Resguardo inicial

linux-7.2.3/arch/powerpc/kexec/Makefile

@@ -0,0 +1,19 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the linux kernel.
+#
+
+obj-y				+= core.o core_$(BITS).o ranges.o
+
+obj-$(CONFIG_PPC32)		+= relocate_32.o
+
+obj-$(CONFIG_KEXEC_FILE)	+= file_load.o file_load_$(BITS).o elf_$(BITS).o
+obj-$(CONFIG_VMCORE_INFO)	+= vmcore_info.o
+obj-$(CONFIG_CRASH_DUMP)	+= crash.o
+
+# Disable GCOV, KCOV & sanitizers in odd or sensitive code
+GCOV_PROFILE_core_$(BITS).o := n
+KCOV_INSTRUMENT_core_$(BITS).o := n
+UBSAN_SANITIZE_core_$(BITS).o := n
+KASAN_SANITIZE_core.o := n
+KASAN_SANITIZE_core_$(BITS).o := n

linux-7.2.3/arch/powerpc/kexec/core.c

@@ -0,0 +1,227 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Code to handle transition of Linux booting another kernel.
+ *
+ * Copyright (C) 2002-2003 Eric Biederman  <ebiederm@xmission.com>
+ * GameCube/ppc32 port Copyright (C) 2004 Albert Herranz
+ * Copyright (C) 2005 IBM Corporation.
+ */
+
+#include <linux/kexec.h>
+#include <linux/reboot.h>
+#include <linux/threads.h>
+#include <linux/memblock.h>
+#include <linux/of.h>
+#include <linux/irq.h>
+#include <linux/ftrace.h>
+
+#include <asm/kdump.h>
+#include <asm/machdep.h>
+#include <asm/pgalloc.h>
+#include <asm/sections.h>
+#include <asm/setup.h>
+#include <asm/firmware.h>
+
+#define cpu_to_be_ulong __PASTE(cpu_to_be, BITS_PER_LONG)
+#define __be_word __PASTE(__be, BITS_PER_LONG)
+
+#ifdef CONFIG_CRASH_DUMP
+void machine_crash_shutdown(struct pt_regs *regs)
+{
+	default_machine_crash_shutdown(regs);
+}
+#endif
+
+void machine_kexec_cleanup(struct kimage *image)
+{
+}
+
+/*
+ * Do not allocate memory (or fail in any way) in machine_kexec().
+ * We are past the point of no return, committed to rebooting now.
+ */
+void machine_kexec(struct kimage *image)
+{
+	int save_ftrace_enabled;
+
+	save_ftrace_enabled = __ftrace_enabled_save();
+	this_cpu_disable_ftrace();
+
+	if (ppc_md.machine_kexec)
+		ppc_md.machine_kexec(image);
+	else
+		default_machine_kexec(image);
+
+	this_cpu_enable_ftrace();
+	__ftrace_enabled_restore(save_ftrace_enabled);
+
+	/* Fall back to normal restart if we're still alive. */
+	machine_restart(NULL);
+	for(;;);
+}
+
+#ifdef CONFIG_CRASH_RESERVE
+
+static unsigned long long crashk_cma_size;
+
+static unsigned long long __init get_crash_base(unsigned long long crash_base)
+{
+
+#ifndef CONFIG_NONSTATIC_KERNEL
+	if (crash_base != KDUMP_KERNELBASE)
+		printk("Crash kernel location must be 0x%x\n",
+				KDUMP_KERNELBASE);
+
+	return KDUMP_KERNELBASE;
+#else
+	unsigned long long crash_base_align;
+
+	if (!crash_base) {
+#ifdef CONFIG_PPC64
+		/*
+		 * On the LPAR platform place the crash kernel to mid of
+		 * RMA size (max. of 512MB) to ensure the crash kernel
+		 * gets enough space to place itself and some stack to be
+		 * in the first segment. At the same time normal kernel
+		 * also get enough space to allocate memory for essential
+		 * system resource in the first segment. Keep the crash
+		 * kernel starts at 128MB offset on other platforms.
+		 */
+		if (firmware_has_feature(FW_FEATURE_LPAR))
+			crash_base = min_t(u64, ppc64_rma_size / 2, SZ_512M);
+		else
+			crash_base = min_t(u64, ppc64_rma_size / 2, SZ_128M);
+#else
+		crash_base = KDUMP_KERNELBASE;
+#endif
+	}
+
+	crash_base_align = PAGE_ALIGN(crash_base);
+	if (crash_base != crash_base_align)
+		pr_warn("Crash kernel base must be aligned to 0x%lx\n", PAGE_SIZE);
+
+	return crash_base_align;
+#endif
+}
+
+void __init arch_reserve_crashkernel(void)
+{
+	unsigned long long crash_size, crash_base, crash_end;
+	unsigned long long kernel_start, kernel_size;
+	unsigned long long total_mem_sz;
+	int ret;
+
+	total_mem_sz = memory_limit ? memory_limit : memblock_phys_mem_size();
+
+	/* use common parsing */
+	ret = parse_crashkernel(boot_command_line, total_mem_sz, &crash_size,
+				&crash_base, NULL, &crashk_cma_size, NULL);
+
+	if (ret)
+		return;
+
+	crash_base = get_crash_base(crash_base);
+	crash_end = crash_base + crash_size - 1;
+
+	kernel_start = __pa(_stext);
+	kernel_size = _end - _stext;
+
+	/* The crash region must not overlap the current kernel */
+	if ((kernel_start + kernel_size > crash_base) && (kernel_start <= crash_end)) {
+		pr_warn("Crash kernel can not overlap current kernel\n");
+		return;
+	}
+
+	reserve_crashkernel_generic(crash_size, crash_base, 0, false);
+}
+
+void __init kdump_cma_reserve(void)
+{
+	if (crashk_cma_size)
+		reserve_crashkernel_cma(crashk_cma_size);
+}
+
+int __init overlaps_crashkernel(unsigned long start, unsigned long size)
+{
+	return (start + size) > crashk_res.start && start <= crashk_res.end;
+}
+
+/* Values we need to export to the second kernel via the device tree. */
+static __be_word crashk_base;
+static __be_word crashk_size;
+static __be_word mem_limit;
+
+static struct property crashk_base_prop = {
+	.name = "linux,crashkernel-base",
+	.length = sizeof(__be_word),
+	.value = &crashk_base
+};
+
+static struct property crashk_size_prop = {
+	.name = "linux,crashkernel-size",
+	.length = sizeof(__be_word),
+	.value = &crashk_size,
+};
+
+static struct property memory_limit_prop = {
+	.name = "linux,memory-limit",
+	.length = sizeof(__be_word),
+	.value = &mem_limit,
+};
+
+static void __init export_crashk_values(struct device_node *node)
+{
+	/* There might be existing crash kernel properties, but we can't
+	 * be sure what's in them, so remove them. */
+	of_remove_property(node, of_find_property(node,
+				"linux,crashkernel-base", NULL));
+	of_remove_property(node, of_find_property(node,
+				"linux,crashkernel-size", NULL));
+
+	if (crashk_res.start != 0) {
+		crashk_base = cpu_to_be_ulong(crashk_res.start),
+		of_add_property(node, &crashk_base_prop);
+		crashk_size = cpu_to_be_ulong(resource_size(&crashk_res));
+		of_add_property(node, &crashk_size_prop);
+	}
+
+	/*
+	 * memory_limit is required by the kexec-tools to limit the
+	 * crash regions to the actual memory used.
+	 */
+	mem_limit = cpu_to_be_ulong(memory_limit);
+	of_update_property(node, &memory_limit_prop);
+}
+#endif /* CONFIG_CRASH_RESERVE */
+
+static __be_word kernel_end;
+
+static struct property kernel_end_prop = {
+	.name = "linux,kernel-end",
+	.length = sizeof(__be_word),
+	.value = &kernel_end,
+};
+
+static int __init kexec_setup(void)
+{
+	struct device_node *node;
+
+	node = of_find_node_by_path("/chosen");
+	if (!node)
+		return -ENOENT;
+
+	/* remove any stale properties so ours can be found */
+	of_remove_property(node, of_find_property(node, kernel_end_prop.name,
+						  NULL));
+
+	/* information needed by userspace when using default_machine_kexec */
+	kernel_end = cpu_to_be_ulong(__pa(_end));
+	of_add_property(node, &kernel_end_prop);
+
+#ifdef CONFIG_CRASH_RESERVE
+	export_crashk_values(node);
+#endif
+	of_node_put(node);
+	return 0;
+}
+late_initcall(kexec_setup);

linux-7.2.3/arch/powerpc/kexec/core_32.c

@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * PPC32 code to handle Linux booting another kernel.
+ *
+ * Copyright (C) 2002-2003 Eric Biederman  <ebiederm@xmission.com>
+ * GameCube/ppc32 port Copyright (C) 2004 Albert Herranz
+ * Copyright (C) 2005 IBM Corporation.
+ */
+
+#include <linux/irq.h>
+#include <linux/kexec.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <asm/cacheflush.h>
+#include <asm/hw_irq.h>
+#include <asm/io.h>
+
+typedef void (*relocate_new_kernel_t)(
+				unsigned long indirection_page,
+				unsigned long reboot_code_buffer,
+				unsigned long start_address) __noreturn;
+
+/*
+ * This is a generic machine_kexec function suitable at least for
+ * non-OpenFirmware embedded platforms.
+ * It merely copies the image relocation code to the control page and
+ * jumps to it.
+ * A platform specific function may just call this one.
+ */
+void default_machine_kexec(struct kimage *image)
+{
+	extern const unsigned int relocate_new_kernel_size;
+	unsigned long page_list;
+	unsigned long reboot_code_buffer, reboot_code_buffer_phys;
+	relocate_new_kernel_t rnk;
+
+	/* Interrupts aren't acceptable while we reboot */
+	local_irq_disable();
+
+	/* mask each interrupt so we are in a more sane state for the
+	 * kexec kernel */
+	machine_kexec_mask_interrupts();
+
+	page_list = image->head;
+
+	/* we need both effective and real address here */
+	reboot_code_buffer =
+			(unsigned long)page_address(image->control_code_page);
+	reboot_code_buffer_phys = virt_to_phys((void *)reboot_code_buffer);
+
+	/* copy our kernel relocation code to the control code page */
+	memcpy((void *)reboot_code_buffer, relocate_new_kernel,
+						relocate_new_kernel_size);
+
+	flush_icache_range(reboot_code_buffer,
+				reboot_code_buffer + KEXEC_CONTROL_PAGE_SIZE);
+	printk(KERN_INFO "Bye!\n");
+
+	if (!IS_ENABLED(CONFIG_PPC_85xx) && !IS_ENABLED(CONFIG_44x))
+		relocate_new_kernel(page_list, reboot_code_buffer_phys, image->start);
+
+	/* now call it */
+	rnk = (relocate_new_kernel_t) reboot_code_buffer;
+	(*rnk)(page_list, reboot_code_buffer_phys, image->start);
+}
+
+int machine_kexec_prepare(struct kimage *image)
+{
+	return 0;
+}

linux-7.2.3/arch/powerpc/kexec/core_64.c

@@ -0,0 +1,561 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * PPC64 code to handle Linux booting another kernel.
+ *
+ * Copyright (C) 2004-2005, IBM Corp.
+ *
+ * Created by: Milton D Miller II
+ */
+
+
+#include <linux/kexec.h>
+#include <linux/smp.h>
+#include <linux/thread_info.h>
+#include <linux/init_task.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/cpu.h>
+#include <linux/hardirq.h>
+#include <linux/of.h>
+#include <linux/libfdt.h>
+
+#include <asm/page.h>
+#include <asm/current.h>
+#include <asm/machdep.h>
+#include <asm/cacheflush.h>
+#include <asm/firmware.h>
+#include <asm/paca.h>
+#include <asm/mmu.h>
+#include <asm/sections.h>	/* _end */
+#include <asm/setup.h>
+#include <asm/smp.h>
+#include <asm/hw_breakpoint.h>
+#include <asm/svm.h>
+#include <asm/ultravisor.h>
+#include <asm/crashdump-ppc64.h>
+
+int machine_kexec_prepare(struct kimage *image)
+{
+	int i;
+	unsigned long begin, end;	/* limits of segment */
+	unsigned long low, high;	/* limits of blocked memory range */
+	struct device_node *node;
+	const unsigned long *basep;
+	const unsigned int *sizep;
+
+	/*
+	 * Since we use the kernel fault handlers and paging code to
+	 * handle the virtual mode, we must make sure no destination
+	 * overlaps kernel static data or bss.
+	 */
+	for (i = 0; i < image->nr_segments; i++)
+		if (image->segment[i].mem < __pa(_end))
+			return -ETXTBSY;
+
+	/* We also should not overwrite the tce tables */
+	for_each_node_by_type(node, "pci") {
+		basep = of_get_property(node, "linux,tce-base", NULL);
+		sizep = of_get_property(node, "linux,tce-size", NULL);
+		if (basep == NULL || sizep == NULL)
+			continue;
+
+		low = *basep;
+		high = low + (*sizep);
+
+		for (i = 0; i < image->nr_segments; i++) {
+			begin = image->segment[i].mem;
+			end = begin + image->segment[i].memsz;
+
+			if ((begin < high) && (end > low)) {
+				of_node_put(node);
+				return -ETXTBSY;
+			}
+		}
+	}
+
+	return 0;
+}
+
+/* Called during kexec sequence with MMU off */
+static notrace void copy_segments(unsigned long ind)
+{
+	unsigned long entry;
+	unsigned long *ptr;
+	void *dest;
+	void *addr;
+
+	/*
+	 * We rely on kexec_load to create a lists that properly
+	 * initializes these pointers before they are used.
+	 * We will still crash if the list is wrong, but at least
+	 * the compiler will be quiet.
+	 */
+	ptr = NULL;
+	dest = NULL;
+
+	for (entry = ind; !(entry & IND_DONE); entry = *ptr++) {
+		addr = __va(entry & PAGE_MASK);
+
+		switch (entry & IND_FLAGS) {
+		case IND_DESTINATION:
+			dest = addr;
+			break;
+		case IND_INDIRECTION:
+			ptr = addr;
+			break;
+		case IND_SOURCE:
+			copy_page(dest, addr);
+			dest += PAGE_SIZE;
+		}
+	}
+}
+
+/* Called during kexec sequence with MMU off */
+notrace void kexec_copy_flush(struct kimage *image)
+{
+	long i, nr_segments = image->nr_segments;
+	struct  kexec_segment ranges[KEXEC_SEGMENT_MAX];
+
+	/* save the ranges on the stack to efficiently flush the icache */
+	memcpy(ranges, image->segment, sizeof(ranges));
+
+	/*
+	 * After this call we may not use anything allocated in dynamic
+	 * memory, including *image.
+	 *
+	 * Only globals and the stack are allowed.
+	 */
+	copy_segments(image->head);
+
+	/*
+	 * we need to clear the icache for all dest pages sometime,
+	 * including ones that were in place on the original copy
+	 */
+	for (i = 0; i < nr_segments; i++)
+		flush_icache_range((unsigned long)__va(ranges[i].mem),
+			(unsigned long)__va(ranges[i].mem + ranges[i].memsz));
+}
+
+#ifdef CONFIG_SMP
+
+static int kexec_all_irq_disabled = 0;
+
+static void kexec_smp_down(void *arg)
+{
+	local_irq_disable();
+	hard_irq_disable();
+
+	mb(); /* make sure our irqs are disabled before we say they are */
+	get_paca()->kexec_state = KEXEC_STATE_IRQS_OFF;
+	while(kexec_all_irq_disabled == 0)
+		cpu_relax();
+	mb(); /* make sure all irqs are disabled before this */
+	hw_breakpoint_disable();
+	/*
+	 * Now every CPU has IRQs off, we can clear out any pending
+	 * IPIs and be sure that no more will come in after this.
+	 */
+	if (ppc_md.kexec_cpu_down)
+		ppc_md.kexec_cpu_down(0, 1);
+
+	reset_sprs();
+
+	kexec_smp_wait();
+	/* NOTREACHED */
+}
+
+static void kexec_prepare_cpus_wait(int wait_state)
+{
+	int my_cpu, i, notified=-1;
+
+	hw_breakpoint_disable();
+	my_cpu = raw_smp_processor_id();
+	/* Make sure each CPU has at least made it to the state we need.
+	 *
+	 * FIXME: There is a (slim) chance of a problem if not all of the CPUs
+	 * are correctly onlined.  If somehow we start a CPU on boot with RTAS
+	 * start-cpu, but somehow that CPU doesn't write callin_cpu_map[] in
+	 * time, the boot CPU will timeout.  If it does eventually execute
+	 * stuff, the secondary will start up (paca_ptrs[]->cpu_start was
+	 * written) and get into a peculiar state.
+	 * If the platform supports smp_ops->take_timebase(), the secondary CPU
+	 * will probably be spinning in there.  If not (i.e. pseries), the
+	 * secondary will continue on and try to online itself/idle/etc. If it
+	 * survives that, we need to find these
+	 * possible-but-not-online-but-should-be CPUs and chaperone them into
+	 * kexec_smp_wait().
+	 */
+	for_each_online_cpu(i) {
+		if (i == my_cpu)
+			continue;
+
+		while (paca_ptrs[i]->kexec_state < wait_state) {
+			barrier();
+			if (i != notified) {
+				printk(KERN_INFO "kexec: waiting for cpu %d "
+				       "(physical %d) to enter %i state\n",
+				       i, paca_ptrs[i]->hw_cpu_id, wait_state);
+				notified = i;
+			}
+		}
+	}
+	mb();
+}
+
+
+/*
+ * The add_cpu() call in wake_offline_cpus() can fail as cpu_bootable()
+ * returns false for CPUs that fail the cpu_smt_thread_allowed() check
+ * or non primary threads if SMT is disabled. Re-enable SMT and set the
+ * number of SMT threads to threads per core.
+ */
+static void kexec_smt_reenable(void)
+{
+#if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT)
+	lock_device_hotplug();
+	cpu_smt_num_threads = threads_per_core;
+	cpu_smt_control = CPU_SMT_ENABLED;
+	unlock_device_hotplug();
+#endif
+}
+
+/*
+ * We need to make sure each present CPU is online.  The next kernel will scan
+ * the device tree and assume primary threads are online and query secondary
+ * threads via RTAS to online them if required.  If we don't online primary
+ * threads, they will be stuck.  However, we also online secondary threads as we
+ * may be using 'cede offline'.  In this case RTAS doesn't see the secondary
+ * threads as offline -- and again, these CPUs will be stuck.
+ *
+ * So, we online all CPUs that should be running, including secondary threads.
+ */
+static void wake_offline_cpus(void)
+{
+	int cpu = 0;
+
+	kexec_smt_reenable();
+
+	for_each_present_cpu(cpu) {
+		if (!cpu_online(cpu)) {
+			printk(KERN_INFO "kexec: Waking offline cpu %d.\n",
+			       cpu);
+			WARN_ON(add_cpu(cpu));
+		}
+	}
+}
+
+static void kexec_prepare_cpus(void)
+{
+	wake_offline_cpus();
+	smp_call_function(kexec_smp_down, NULL, /* wait */0);
+	local_irq_disable();
+	hard_irq_disable();
+
+	mb(); /* make sure IRQs are disabled before we say they are */
+	get_paca()->kexec_state = KEXEC_STATE_IRQS_OFF;
+
+	kexec_prepare_cpus_wait(KEXEC_STATE_IRQS_OFF);
+	/* we are sure every CPU has IRQs off at this point */
+	kexec_all_irq_disabled = 1;
+
+	/*
+	 * Before removing MMU mappings make sure all CPUs have entered real
+	 * mode:
+	 */
+	kexec_prepare_cpus_wait(KEXEC_STATE_REAL_MODE);
+
+	/* after we tell the others to go down */
+	if (ppc_md.kexec_cpu_down)
+		ppc_md.kexec_cpu_down(0, 0);
+}
+
+#else /* ! SMP */
+
+static void kexec_prepare_cpus(void)
+{
+	/*
+	 * move the secondarys to us so that we can copy
+	 * the new kernel 0-0x100 safely
+	 *
+	 * do this if kexec in setup.c ?
+	 *
+	 * We need to release the cpus if we are ever going from an
+	 * UP to an SMP kernel.
+	 */
+	smp_release_cpus();
+	if (ppc_md.kexec_cpu_down)
+		ppc_md.kexec_cpu_down(0, 0);
+	local_irq_disable();
+	hard_irq_disable();
+}
+
+#endif /* SMP */
+
+/*
+ * kexec thread structure and stack.
+ *
+ * We need to make sure that this is 16384-byte aligned due to the
+ * way process stacks are handled.  It also must be statically allocated
+ * or allocated as part of the kimage, because everything else may be
+ * overwritten when we copy the kexec image.  We piggyback on the
+ * "init_task" linker section here to statically allocate a stack.
+ *
+ * We could use a smaller stack if we don't care about anything using
+ * current, but that audit has not been performed.
+ */
+static union thread_union kexec_stack = { };
+
+/*
+ * For similar reasons to the stack above, the kexecing CPU needs to be on a
+ * static PACA; we switch to kexec_paca.
+ */
+static struct paca_struct kexec_paca;
+
+/* Our assembly helper, in misc_64.S */
+extern void kexec_sequence(void *newstack, unsigned long start,
+			   void *image, void *control,
+			   void (*clear_all)(void),
+			   bool copy_with_mmu_off) __noreturn;
+
+/* too late to fail here */
+void default_machine_kexec(struct kimage *image)
+{
+	bool copy_with_mmu_off;
+
+	/* prepare control code if any */
+
+	/*
+        * If the kexec boot is the normal one, need to shutdown other cpus
+        * into our wait loop and quiesce interrupts.
+        * Otherwise, in the case of crashed mode (crashing_cpu >= 0),
+        * stopping other CPUs and collecting their pt_regs is done before
+        * using debugger IPI.
+        */
+
+	if (!kdump_in_progress())
+		kexec_prepare_cpus();
+
+#ifdef CONFIG_PPC_PSERIES
+	/*
+	 * This must be done after other CPUs have shut down, otherwise they
+	 * could execute the 'scv' instruction, which is not supported with
+	 * reloc disabled (see configure_exceptions()).
+	 */
+	if (firmware_has_feature(FW_FEATURE_SET_MODE))
+		pseries_disable_reloc_on_exc();
+#endif
+
+	printk("kexec: Starting switchover sequence.\n");
+
+	/* switch to a staticly allocated stack.  Based on irq stack code.
+	 * We setup preempt_count to avoid using VMX in memcpy.
+	 * XXX: the task struct will likely be invalid once we do the copy!
+	 */
+	current_thread_info()->flags = 0;
+	current_thread_info()->preempt_count = HARDIRQ_OFFSET;
+
+	/* We need a static PACA, too; copy this CPU's PACA over and switch to
+	 * it. Also poison per_cpu_offset and NULL lppaca to catch anyone using
+	 * non-static data.
+	 */
+	memcpy(&kexec_paca, get_paca(), sizeof(struct paca_struct));
+	kexec_paca.data_offset = 0xedeaddeadeeeeeeeUL;
+#ifdef CONFIG_PPC_PSERIES
+	kexec_paca.lppaca_ptr = NULL;
+#endif
+
+	if (is_secure_guest() && !(image->preserve_context ||
+				   image->type == KEXEC_TYPE_CRASH)) {
+		uv_unshare_all_pages();
+		printk("kexec: Unshared all shared pages.\n");
+	}
+
+	paca_ptrs[kexec_paca.paca_index] = &kexec_paca;
+
+	setup_paca(&kexec_paca);
+
+	/*
+	 * The lppaca should be unregistered at this point so the HV won't
+	 * touch it. In the case of a crash, none of the lppacas are
+	 * unregistered so there is not much we can do about it here.
+	 */
+
+	/*
+	 * On Book3S, the copy must happen with the MMU off if we are either
+	 * using Radix page tables or we are not in an LPAR since we can
+	 * overwrite the page tables while copying.
+	 *
+	 * In an LPAR, we keep the MMU on otherwise we can't access beyond
+	 * the RMA. On BookE there is no real MMU off mode, so we have to
+	 * keep it enabled as well (but then we have bolted TLB entries).
+	 */
+#ifdef CONFIG_PPC_BOOK3E_64
+	copy_with_mmu_off = false;
+#else
+	copy_with_mmu_off = radix_enabled() ||
+		!(firmware_has_feature(FW_FEATURE_LPAR) ||
+		  firmware_has_feature(FW_FEATURE_PS3_LV1));
+#endif
+
+	/* Some things are best done in assembly.  Finding globals with
+	 * a toc is easier in C, so pass in what we can.
+	 */
+	kexec_sequence(&kexec_stack, image->start, image,
+		       page_address(image->control_code_page),
+		       mmu_cleanup_all, copy_with_mmu_off);
+	/* NOTREACHED */
+}
+
+#ifdef CONFIG_PPC_64S_HASH_MMU
+/* Values we need to export to the second kernel via the device tree. */
+static __be64 htab_base;
+static __be64 htab_size;
+
+static struct property htab_base_prop = {
+	.name = "linux,htab-base",
+	.length = sizeof(unsigned long),
+	.value = &htab_base,
+};
+
+static struct property htab_size_prop = {
+	.name = "linux,htab-size",
+	.length = sizeof(unsigned long),
+	.value = &htab_size,
+};
+
+static int __init export_htab_values(void)
+{
+	struct device_node *node;
+
+	/* On machines with no htab htab_address is NULL */
+	if (!htab_address)
+		return -ENODEV;
+
+	node = of_find_node_by_path("/chosen");
+	if (!node)
+		return -ENODEV;
+
+	/* remove any stale properties so ours can be found */
+	of_remove_property(node, of_find_property(node, htab_base_prop.name, NULL));
+	of_remove_property(node, of_find_property(node, htab_size_prop.name, NULL));
+
+	htab_base = cpu_to_be64(__pa(htab_address));
+	of_add_property(node, &htab_base_prop);
+	htab_size = cpu_to_be64(htab_size_bytes);
+	of_add_property(node, &htab_size_prop);
+
+	of_node_put(node);
+	return 0;
+}
+late_initcall(export_htab_values);
+#endif /* CONFIG_PPC_64S_HASH_MMU */
+
+#if defined(CONFIG_KEXEC_FILE) || defined(CONFIG_CRASH_DUMP)
+/**
+ * add_node_props - Reads node properties from device node structure and add
+ *                  them to fdt.
+ * @fdt:            Flattened device tree of the kernel
+ * @node_offset:    offset of the node to add a property at
+ * @dn:             device node pointer
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+static int add_node_props(void *fdt, int node_offset, const struct device_node *dn)
+{
+	int ret = 0;
+	struct property *pp;
+
+	if (!dn)
+		return -EINVAL;
+
+	for_each_property_of_node(dn, pp) {
+		ret = fdt_setprop(fdt, node_offset, pp->name, pp->value, pp->length);
+		if (ret < 0) {
+			pr_err("Unable to add %s property: %s\n", pp->name, fdt_strerror(ret));
+			return ret;
+		}
+	}
+	return ret;
+}
+
+/**
+ * update_cpus_node - Update cpus node of flattened device tree using of_root
+ *                    device node.
+ * @fdt:              Flattened device tree of the kernel.
+ *
+ * Returns 0 on success, negative errno on error.
+ *
+ * Note: expecting no subnodes under /cpus/<node> with device_type == "cpu".
+ * If this changes, update this function to include them.
+ */
+int update_cpus_node(void *fdt)
+{
+	int prev_node_offset;
+	const char *device_type;
+	const struct fdt_property *prop;
+	struct device_node *cpus_node, *dn;
+	int cpus_offset, cpus_subnode_offset, ret = 0;
+
+	cpus_offset = fdt_path_offset(fdt, "/cpus");
+	if (cpus_offset < 0 && cpus_offset != -FDT_ERR_NOTFOUND) {
+		pr_err("Malformed device tree: error reading /cpus node: %s\n",
+		       fdt_strerror(cpus_offset));
+		return cpus_offset;
+	}
+
+	prev_node_offset = cpus_offset;
+	/* Delete sub-nodes of /cpus node with device_type == "cpu" */
+	for (cpus_subnode_offset = fdt_first_subnode(fdt, cpus_offset); cpus_subnode_offset >= 0;) {
+		/* Ignore nodes that do not have a device_type property or device_type != "cpu" */
+		prop = fdt_get_property(fdt, cpus_subnode_offset, "device_type", NULL);
+		if (!prop || strcmp(prop->data, "cpu")) {
+			prev_node_offset = cpus_subnode_offset;
+			goto next_node;
+		}
+
+		ret = fdt_del_node(fdt, cpus_subnode_offset);
+		if (ret < 0) {
+			pr_err("Failed to delete a cpus sub-node: %s\n", fdt_strerror(ret));
+			return ret;
+		}
+next_node:
+		if (prev_node_offset == cpus_offset)
+			cpus_subnode_offset = fdt_first_subnode(fdt, cpus_offset);
+		else
+			cpus_subnode_offset = fdt_next_subnode(fdt, prev_node_offset);
+	}
+
+	cpus_node = of_find_node_by_path("/cpus");
+	/* Fail here to avoid kexec/kdump kernel boot hung */
+	if (!cpus_node) {
+		pr_err("No /cpus node found\n");
+		return -EINVAL;
+	}
+
+	/* Add all /cpus sub-nodes of device_type == "cpu" to FDT */
+	for_each_child_of_node(cpus_node, dn) {
+		/* Ignore device nodes that do not have a device_type property
+		 * or device_type != "cpu".
+		 */
+		device_type = of_get_property(dn, "device_type", NULL);
+		if (!device_type || strcmp(device_type, "cpu"))
+			continue;
+
+		cpus_subnode_offset = fdt_add_subnode(fdt, cpus_offset, dn->full_name);
+		if (cpus_subnode_offset < 0) {
+			pr_err("Unable to add %s subnode: %s\n", dn->full_name,
+			       fdt_strerror(cpus_subnode_offset));
+			ret = cpus_subnode_offset;
+			goto out;
+		}
+
+		ret = add_node_props(fdt, cpus_subnode_offset, dn);
+		if (ret < 0)
+			goto out;
+	}
+out:
+	of_node_put(cpus_node);
+	of_node_put(dn);
+	return ret;
+}
+#endif /* CONFIG_KEXEC_FILE || CONFIG_CRASH_DUMP */

linux-7.2.3/arch/powerpc/kexec/crash.c

@@ -0,0 +1,656 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Architecture specific (PPC64) functions for kexec based crash dumps.
+ *
+ * Copyright (C) 2005, IBM Corp.
+ *
+ * Created by: Haren Myneni
+ */
+
+#include <linux/kernel.h>
+#include <linux/smp.h>
+#include <linux/reboot.h>
+#include <linux/kexec.h>
+#include <linux/export.h>
+#include <linux/crash_dump.h>
+#include <linux/delay.h>
+#include <linux/irq.h>
+#include <linux/types.h>
+#include <linux/libfdt.h>
+#include <linux/memory.h>
+
+#include <asm/processor.h>
+#include <asm/machdep.h>
+#include <asm/kexec.h>
+#include <asm/smp.h>
+#include <asm/setjmp.h>
+#include <asm/debug.h>
+#include <asm/interrupt.h>
+#include <asm/kexec_ranges.h>
+#include <asm/crashdump-ppc64.h>
+
+/*
+ * The primary CPU waits a while for all secondary CPUs to enter. This is to
+ * avoid sending an IPI if the secondary CPUs are entering
+ * crash_kexec_secondary on their own (eg via a system reset).
+ *
+ * The secondary timeout has to be longer than the primary. Both timeouts are
+ * in milliseconds.
+ */
+#define PRIMARY_TIMEOUT		500
+#define SECONDARY_TIMEOUT	1000
+
+#define IPI_TIMEOUT		10000
+#define REAL_MODE_TIMEOUT	10000
+
+static int time_to_dump;
+
+/*
+ * In case of system reset, secondary CPUs enter crash_kexec_secondary with out
+ * having to send an IPI explicitly. So, indicate if the crash is via
+ * system reset to avoid sending another IPI.
+ */
+static int is_via_system_reset;
+
+/*
+ * crash_wake_offline should be set to 1 by platforms that intend to wake
+ * up offline cpus prior to jumping to a kdump kernel. Currently powernv
+ * sets it to 1, since we want to avoid things from happening when an
+ * offline CPU wakes up due to something like an HMI (malfunction error),
+ * which propagates to all threads.
+ */
+int crash_wake_offline;
+
+#define CRASH_HANDLER_MAX 3
+/* List of shutdown handles */
+static crash_shutdown_t crash_shutdown_handles[CRASH_HANDLER_MAX];
+static DEFINE_SPINLOCK(crash_handlers_lock);
+
+static unsigned long crash_shutdown_buf[JMP_BUF_LEN];
+static int crash_shutdown_cpu = -1;
+
+static int handle_fault(struct pt_regs *regs)
+{
+	if (crash_shutdown_cpu == smp_processor_id())
+		longjmp(crash_shutdown_buf, 1);
+	return 0;
+}
+
+#ifdef CONFIG_SMP
+
+static atomic_t cpus_in_crash;
+void crash_ipi_callback(struct pt_regs *regs)
+{
+	static cpumask_t cpus_state_saved = CPU_MASK_NONE;
+
+	int cpu = smp_processor_id();
+
+	hard_irq_disable();
+	if (!cpumask_test_cpu(cpu, &cpus_state_saved)) {
+		crash_save_cpu(regs, cpu);
+		cpumask_set_cpu(cpu, &cpus_state_saved);
+	}
+
+	atomic_inc(&cpus_in_crash);
+	smp_mb__after_atomic();
+
+	/*
+	 * Starting the kdump boot.
+	 * This barrier is needed to make sure that all CPUs are stopped.
+	 */
+	while (!time_to_dump)
+		cpu_relax();
+
+	if (ppc_md.kexec_cpu_down)
+		ppc_md.kexec_cpu_down(1, 1);
+
+#ifdef CONFIG_PPC64
+	kexec_smp_wait();
+#else
+	for (;;);	/* FIXME */
+#endif
+
+	/* NOTREACHED */
+}
+
+static void crash_kexec_prepare_cpus(void)
+{
+	unsigned int msecs;
+	volatile unsigned int ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */
+	volatile int tries = 0;
+	int (*old_handler)(struct pt_regs *regs);
+
+	printk(KERN_EMERG "Sending IPI to other CPUs\n");
+
+	if (crash_wake_offline)
+		ncpus = num_present_cpus() - 1;
+
+	/*
+	 * If we came in via system reset, secondaries enter via crash_kexec_secondary().
+	 * So, wait a while for the secondary CPUs to enter for that case.
+	 * Else, send IPI to all other CPUs.
+	 */
+	if (is_via_system_reset)
+		mdelay(PRIMARY_TIMEOUT);
+	else
+		crash_send_ipi(crash_ipi_callback);
+	smp_wmb();
+
+again:
+	/*
+	 * FIXME: Until we will have the way to stop other CPUs reliably,
+	 * the crash CPU will send an IPI and wait for other CPUs to
+	 * respond.
+	 */
+	msecs = IPI_TIMEOUT;
+	while ((atomic_read(&cpus_in_crash) < ncpus) && (--msecs > 0))
+		mdelay(1);
+
+	/* Would it be better to replace the trap vector here? */
+
+	if (atomic_read(&cpus_in_crash) >= ncpus) {
+		printk(KERN_EMERG "IPI complete\n");
+		return;
+	}
+
+	printk(KERN_EMERG "ERROR: %d cpu(s) not responding\n",
+		ncpus - atomic_read(&cpus_in_crash));
+
+	/*
+	 * If we have a panic timeout set then we can't wait indefinitely
+	 * for someone to activate system reset. We also give up on the
+	 * second time through if system reset fail to work.
+	 */
+	if ((panic_timeout > 0) || (tries > 0))
+		return;
+
+	/*
+	 * A system reset will cause all CPUs to take an 0x100 exception.
+	 * The primary CPU returns here via setjmp, and the secondary
+	 * CPUs reexecute the crash_kexec_secondary path.
+	 */
+	old_handler = __debugger;
+	__debugger = handle_fault;
+	crash_shutdown_cpu = smp_processor_id();
+
+	if (setjmp(crash_shutdown_buf) == 0) {
+		printk(KERN_EMERG "Activate system reset (dumprestart) "
+				  "to stop other cpu(s)\n");
+
+		/*
+		 * A system reset will force all CPUs to execute the
+		 * crash code again. We need to reset cpus_in_crash so we
+		 * wait for everyone to do this.
+		 */
+		atomic_set(&cpus_in_crash, 0);
+		smp_mb();
+
+		while (atomic_read(&cpus_in_crash) < ncpus)
+			cpu_relax();
+	}
+
+	crash_shutdown_cpu = -1;
+	__debugger = old_handler;
+
+	tries++;
+	goto again;
+}
+
+/*
+ * This function will be called by secondary cpus.
+ */
+void crash_kexec_secondary(struct pt_regs *regs)
+{
+	unsigned long flags;
+	int msecs = SECONDARY_TIMEOUT;
+
+	local_irq_save(flags);
+
+	/* Wait for the primary crash CPU to signal its progress */
+	while (crashing_cpu < 0) {
+		if (--msecs < 0) {
+			/* No response, kdump image may not have been loaded */
+			local_irq_restore(flags);
+			return;
+		}
+
+		mdelay(1);
+	}
+
+	crash_ipi_callback(regs);
+}
+
+#else	/* ! CONFIG_SMP */
+
+static void crash_kexec_prepare_cpus(void)
+{
+	/*
+	 * move the secondaries to us so that we can copy
+	 * the new kernel 0-0x100 safely
+	 *
+	 * do this if kexec in setup.c ?
+	 */
+#ifdef CONFIG_PPC64
+	smp_release_cpus();
+#else
+	/* FIXME */
+#endif
+}
+
+void crash_kexec_secondary(struct pt_regs *regs)
+{
+}
+#endif	/* CONFIG_SMP */
+
+/* wait for all the CPUs to hit real mode but timeout if they don't come in */
+#if defined(CONFIG_SMP) && defined(CONFIG_PPC64)
+noinstr static void __maybe_unused crash_kexec_wait_realmode(int cpu)
+{
+	unsigned int msecs;
+	int i;
+
+	msecs = REAL_MODE_TIMEOUT;
+	for (i=0; i < nr_cpu_ids && msecs > 0; i++) {
+		if (i == cpu)
+			continue;
+
+		while (paca_ptrs[i]->kexec_state < KEXEC_STATE_REAL_MODE) {
+			barrier();
+			if (!cpu_possible(i) || !cpu_online(i) || (msecs <= 0))
+				break;
+			msecs--;
+			mdelay(1);
+		}
+	}
+	mb();
+}
+#else
+static inline void crash_kexec_wait_realmode(int cpu) {}
+#endif	/* CONFIG_SMP && CONFIG_PPC64 */
+
+void crash_kexec_prepare(void)
+{
+	/* Avoid hardlocking with irresponsive CPU holding logbuf_lock */
+	printk_deferred_enter();
+
+	/*
+	 * This function is only called after the system
+	 * has panicked or is otherwise in a critical state.
+	 * The minimum amount of code to allow a kexec'd kernel
+	 * to run successfully needs to happen here.
+	 *
+	 * In practice this means stopping other cpus in
+	 * an SMP system.
+	 * The kernel is broken so disable interrupts.
+	 */
+	hard_irq_disable();
+
+	/*
+	 * Make a note of crashing cpu. Will be used in machine_kexec
+	 * such that another IPI will not be sent.
+	 */
+	crashing_cpu = smp_processor_id();
+
+	crash_kexec_prepare_cpus();
+}
+
+/*
+ * Register a function to be called on shutdown.  Only use this if you
+ * can't reset your device in the second kernel.
+ */
+int crash_shutdown_register(crash_shutdown_t handler)
+{
+	unsigned int i, rc;
+
+	spin_lock(&crash_handlers_lock);
+	for (i = 0 ; i < CRASH_HANDLER_MAX; i++)
+		if (!crash_shutdown_handles[i]) {
+			/* Insert handle at first empty entry */
+			crash_shutdown_handles[i] = handler;
+			rc = 0;
+			break;
+		}
+
+	if (i == CRASH_HANDLER_MAX) {
+		printk(KERN_ERR "Crash shutdown handles full, "
+		       "not registered.\n");
+		rc = 1;
+	}
+
+	spin_unlock(&crash_handlers_lock);
+	return rc;
+}
+EXPORT_SYMBOL(crash_shutdown_register);
+
+int crash_shutdown_unregister(crash_shutdown_t handler)
+{
+	unsigned int i, rc;
+
+	spin_lock(&crash_handlers_lock);
+	for (i = 0 ; i < CRASH_HANDLER_MAX; i++)
+		if (crash_shutdown_handles[i] == handler)
+			break;
+
+	if (i == CRASH_HANDLER_MAX) {
+		printk(KERN_ERR "Crash shutdown handle not found\n");
+		rc = 1;
+	} else {
+		/* Shift handles down */
+		for (; i < (CRASH_HANDLER_MAX - 1); i++)
+			crash_shutdown_handles[i] =
+				crash_shutdown_handles[i+1];
+		/*
+		 * Reset last entry to NULL now that it has been shifted down,
+		 * this will allow new handles to be added here.
+		 */
+		crash_shutdown_handles[i] = NULL;
+		rc = 0;
+	}
+
+	spin_unlock(&crash_handlers_lock);
+	return rc;
+}
+EXPORT_SYMBOL(crash_shutdown_unregister);
+
+void default_machine_crash_shutdown(struct pt_regs *regs)
+{
+	volatile unsigned int i;
+	int (*old_handler)(struct pt_regs *regs);
+
+	if (TRAP(regs) == INTERRUPT_SYSTEM_RESET)
+		is_via_system_reset = 1;
+
+	if (IS_ENABLED(CONFIG_SMP))
+		crash_smp_send_stop();
+	else
+		crash_kexec_prepare();
+
+	crash_save_cpu(regs, crashing_cpu);
+
+	time_to_dump = 1;
+
+	crash_kexec_wait_realmode(crashing_cpu);
+
+	machine_kexec_mask_interrupts();
+
+	/*
+	 * Call registered shutdown routines safely.  Swap out
+	 * __debugger_fault_handler, and replace on exit.
+	 */
+	old_handler = __debugger_fault_handler;
+	__debugger_fault_handler = handle_fault;
+	crash_shutdown_cpu = smp_processor_id();
+	for (i = 0; i < CRASH_HANDLER_MAX && crash_shutdown_handles[i]; i++) {
+		if (setjmp(crash_shutdown_buf) == 0) {
+			/*
+			 * Insert syncs and delay to ensure
+			 * instructions in the dangerous region don't
+			 * leak away from this protected region.
+			 */
+			asm volatile("sync; isync");
+			/* dangerous region */
+			crash_shutdown_handles[i]();
+			asm volatile("sync; isync");
+		}
+	}
+	crash_shutdown_cpu = -1;
+	__debugger_fault_handler = old_handler;
+
+	if (ppc_md.kexec_cpu_down)
+		ppc_md.kexec_cpu_down(1, 0);
+}
+
+#ifdef CONFIG_CRASH_DUMP
+/**
+ * sync_backup_region_phdr - synchronize backup region offset between
+ *			    kexec image and ELF core header.
+ * @image: Kexec image.
+ * @ehdr: ELF core header.
+ * @phdr_to_kimage: If true, read the offset from the ELF program header
+ *		    and update the kimage backup region. If false, update
+ *		    the ELF program header offset from the kimage backup
+ *		    region.
+ *
+ * Note: During kexec_load, this is called with phdr_to_kimage = true. For
+ * kexec_file_load and ELF core header recreation during memory hotplug
+ * events, it is called with phdr_to_kimage = false.
+ *
+ * Returns nothing.
+ */
+void sync_backup_region_phdr(struct kimage *image, Elf64_Ehdr *ehdr, bool phdr_to_kimage)
+{
+	Elf64_Phdr *phdr;
+	unsigned int i;
+
+	phdr = (Elf64_Phdr *)(ehdr + 1);
+	for (i = 0; i < ehdr->e_phnum; i++, phdr++) {
+		if (phdr->p_paddr == BACKUP_SRC_START) {
+			if (phdr_to_kimage)
+				image->arch.backup_start = phdr->p_offset;
+			else
+				phdr->p_offset = image->arch.backup_start;
+
+			kexec_dprintk("Backup region offset updated to 0x%lx\n",
+				      image->arch.backup_start);
+			return;
+		}
+	}
+}
+#endif /* CONFIG_CRASH_DUMP */
+
+#ifdef CONFIG_CRASH_HOTPLUG
+
+int machine_kexec_post_load(struct kimage *image)
+{
+	int i;
+	unsigned long mem;
+	unsigned char *ptr;
+
+	if (image->type != KEXEC_TYPE_CRASH)
+		return 0;
+
+	if (image->file_mode)
+		return 0;
+
+	for (i = 0; i < image->nr_segments; i++) {
+		mem = image->segment[i].mem;
+		ptr = (char *)__va(mem);
+
+		if (ptr && memcmp(ptr, ELFMAG, SELFMAG) == 0)
+			sync_backup_region_phdr(image, (Elf64_Ehdr *) ptr, true);
+	}
+	return 0;
+}
+
+#undef pr_fmt
+#define pr_fmt(fmt) "crash hp: " fmt
+
+/*
+ * Advertise preferred elfcorehdr size to userspace via
+ * /sys/kernel/crash_elfcorehdr_size sysfs interface.
+ */
+unsigned int arch_crash_get_elfcorehdr_size(void)
+{
+	unsigned long phdr_cnt;
+
+	/* A program header for possible CPUs + vmcoreinfo */
+	phdr_cnt = num_possible_cpus() + 1;
+	if (IS_ENABLED(CONFIG_MEMORY_HOTPLUG))
+		phdr_cnt += CONFIG_CRASH_MAX_MEMORY_RANGES;
+
+	return sizeof(struct elfhdr) + (phdr_cnt * sizeof(Elf64_Phdr));
+}
+
+/**
+ * update_crash_elfcorehdr() - Recreate the elfcorehdr and replace it with old
+ *			       elfcorehdr in the kexec segment array.
+ * @image: the active struct kimage
+ * @mn: struct memory_notify data handler
+ */
+static void update_crash_elfcorehdr(struct kimage *image, struct memory_notify *mn)
+{
+	int ret;
+	struct crash_mem *cmem = NULL;
+	struct kexec_segment *ksegment;
+	void *ptr, *mem, *elfbuf = NULL;
+	unsigned long elfsz, memsz, base_addr, size;
+
+	ksegment = &image->segment[image->elfcorehdr_index];
+	mem = (void *) ksegment->mem;
+	memsz = ksegment->memsz;
+
+	ret = get_crash_memory_ranges(&cmem);
+	if (ret) {
+		pr_err("Failed to get crash mem range\n");
+		return;
+	}
+
+	/*
+	 * The hot unplugged memory is part of crash memory ranges,
+	 * remove it here.
+	 */
+	if (image->hp_action == KEXEC_CRASH_HP_REMOVE_MEMORY) {
+		base_addr = PFN_PHYS(mn->start_pfn);
+		size = mn->nr_pages * PAGE_SIZE;
+		ret = remove_mem_range(&cmem, base_addr, size);
+		if (ret) {
+			pr_err("Failed to remove hot-unplugged memory from crash memory ranges\n");
+			goto out;
+		}
+	}
+
+	ret = crash_prepare_elf64_headers(cmem, false, &elfbuf, &elfsz);
+	if (ret) {
+		pr_err("Failed to prepare elf header\n");
+		goto out;
+	}
+
+	/*
+	 * It is unlikely that kernel hit this because elfcorehdr kexec
+	 * segment (memsz) is built with addition space to accommodate growing
+	 * number of crash memory ranges while loading the kdump kernel. It is
+	 * Just to avoid any unforeseen case.
+	 */
+	if (elfsz > memsz) {
+		pr_err("Updated crash elfcorehdr elfsz %lu > memsz %lu", elfsz, memsz);
+		goto out;
+	}
+
+	sync_backup_region_phdr(image, (Elf64_Ehdr *) elfbuf, false);
+
+	ptr = __va(mem);
+	if (ptr) {
+		/* Temporarily invalidate the crash image while it is replaced */
+		xchg(&kexec_crash_image, NULL);
+
+		/* Replace the old elfcorehdr with newly prepared elfcorehdr */
+		memcpy((void *)ptr, elfbuf, elfsz);
+
+		/* The crash image is now valid once again */
+		xchg(&kexec_crash_image, image);
+	}
+out:
+	kvfree(cmem);
+	kvfree(elfbuf);
+}
+
+/**
+ * get_fdt_index - Loop through the kexec segment array and find
+ *		   the index of the FDT segment.
+ * @image: a pointer to kexec_crash_image
+ *
+ * Returns the index of FDT segment in the kexec segment array
+ * if found; otherwise -1.
+ */
+static int get_fdt_index(struct kimage *image)
+{
+	void *ptr;
+	unsigned long mem;
+	int i, fdt_index = -1;
+
+	/* Find the FDT segment index in kexec segment array. */
+	for (i = 0; i < image->nr_segments; i++) {
+		mem = image->segment[i].mem;
+		ptr = __va(mem);
+
+		if (ptr && fdt_magic(ptr) == FDT_MAGIC) {
+			fdt_index = i;
+			break;
+		}
+	}
+
+	return fdt_index;
+}
+
+/**
+ * update_crash_fdt - updates the cpus node of the crash FDT.
+ *
+ * @image: a pointer to kexec_crash_image
+ */
+static void update_crash_fdt(struct kimage *image)
+{
+	void *fdt;
+	int fdt_index;
+
+	fdt_index = get_fdt_index(image);
+	if (fdt_index < 0) {
+		pr_err("Unable to locate FDT segment.\n");
+		return;
+	}
+
+	fdt = __va((void *)image->segment[fdt_index].mem);
+
+	/* Temporarily invalidate the crash image while it is replaced */
+	xchg(&kexec_crash_image, NULL);
+
+	/* update FDT to reflect changes in CPU resources */
+	if (update_cpus_node(fdt))
+		pr_err("Failed to update crash FDT");
+
+	/* The crash image is now valid once again */
+	xchg(&kexec_crash_image, image);
+}
+
+int arch_crash_hotplug_support(struct kimage *image, unsigned long kexec_flags)
+{
+#ifdef CONFIG_KEXEC_FILE
+	if (image->file_mode)
+		return 1;
+#endif
+	return kexec_flags & KEXEC_CRASH_HOTPLUG_SUPPORT;
+}
+
+/**
+ * arch_crash_handle_hotplug_event - Handle crash CPU/Memory hotplug events to update the
+ *				     necessary kexec segments based on the hotplug event.
+ * @image: a pointer to kexec_crash_image
+ * @arg: struct memory_notify handler for memory hotplug case and NULL for CPU hotplug case.
+ *
+ * Update the kdump image based on the type of hotplug event, represented by image->hp_action.
+ * CPU add: Update the FDT segment to include the newly added CPU.
+ * CPU remove: No action is needed, with the assumption that it's okay to have offline CPUs
+ *	       part of the FDT.
+ * Memory add/remove: No action is taken as this is not yet supported.
+ */
+void arch_crash_handle_hotplug_event(struct kimage *image, void *arg)
+{
+	struct memory_notify *mn;
+
+	switch (image->hp_action) {
+	case KEXEC_CRASH_HP_REMOVE_CPU:
+		return;
+
+	case KEXEC_CRASH_HP_ADD_CPU:
+		update_crash_fdt(image);
+		break;
+
+	case KEXEC_CRASH_HP_REMOVE_MEMORY:
+	case KEXEC_CRASH_HP_ADD_MEMORY:
+		mn = (struct memory_notify *)arg;
+		update_crash_elfcorehdr(image, mn);
+		return;
+	default:
+		pr_warn_once("Unknown hotplug action\n");
+	}
+}
+#endif /* CONFIG_CRASH_HOTPLUG */

linux-7.2.3/arch/powerpc/kexec/elf_64.c

@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Load ELF vmlinux file for the kexec_file_load syscall.
+ *
+ * Copyright (C) 2004  Adam Litke (agl@us.ibm.com)
+ * Copyright (C) 2004  IBM Corp.
+ * Copyright (C) 2005  R Sharada (sharada@in.ibm.com)
+ * Copyright (C) 2006  Mohan Kumar M (mohan@in.ibm.com)
+ * Copyright (C) 2016  IBM Corporation
+ *
+ * Based on kexec-tools' kexec-elf-exec.c and kexec-elf-ppc64.c.
+ * Heavily modified for the kernel by
+ * Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>.
+ */
+
+#define pr_fmt(fmt)	"kexec_elf: " fmt
+
+#include <linux/elf.h>
+#include <linux/kexec.h>
+#include <linux/libfdt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <asm/kexec_ranges.h>
+
+static void *elf64_load(struct kimage *image, char *kernel_buf,
+			unsigned long kernel_len, char *initrd,
+			unsigned long initrd_len, char *cmdline,
+			unsigned long cmdline_len)
+{
+	int ret;
+	unsigned long kernel_load_addr;
+	unsigned long initrd_load_addr = 0, fdt_load_addr;
+	void *fdt;
+	const void *slave_code;
+	struct elfhdr ehdr;
+	char *modified_cmdline = NULL;
+	struct crash_mem *rmem = NULL;
+	struct kexec_elf_info elf_info;
+	struct kexec_buf kbuf = { .image = image, .buf_min = 0,
+				  .buf_max = ppc64_rma_size };
+	struct kexec_buf pbuf = { .image = image, .buf_min = 0,
+				  .buf_max = ppc64_rma_size, .top_down = true,
+				  .mem = KEXEC_BUF_MEM_UNKNOWN };
+
+	ret = kexec_build_elf_info(kernel_buf, kernel_len, &ehdr, &elf_info);
+	if (ret)
+		return ERR_PTR(ret);
+
+	if (IS_ENABLED(CONFIG_CRASH_DUMP) && image->type == KEXEC_TYPE_CRASH) {
+		/* min & max buffer values for kdump case */
+		kbuf.buf_min = pbuf.buf_min = crashk_res.start;
+		kbuf.buf_max = pbuf.buf_max =
+				((crashk_res.end < ppc64_rma_size) ?
+				 crashk_res.end : (ppc64_rma_size - 1));
+	}
+
+	ret = kexec_elf_load(image, &ehdr, &elf_info, &kbuf, &kernel_load_addr);
+	if (ret)
+		goto out;
+
+	kexec_dprintk("Loaded the kernel at 0x%lx\n", kernel_load_addr);
+
+	ret = kexec_load_purgatory(image, &pbuf);
+	if (ret) {
+		pr_err("Loading purgatory failed.\n");
+		goto out;
+	}
+
+	kexec_dprintk("Loaded purgatory at 0x%lx\n", pbuf.mem);
+
+	/* Load additional segments needed for panic kernel */
+	if (IS_ENABLED(CONFIG_CRASH_DUMP) && image->type == KEXEC_TYPE_CRASH) {
+		ret = load_crashdump_segments_ppc64(image, &kbuf);
+		if (ret) {
+			pr_err("Failed to load kdump kernel segments\n");
+			goto out;
+		}
+
+		ret = crash_load_dm_crypt_keys(image);
+		if (ret)
+			goto out;
+
+		/* Setup cmdline for kdump kernel case */
+		modified_cmdline = setup_kdump_cmdline(image, cmdline,
+						       cmdline_len);
+		if (!modified_cmdline) {
+			pr_err("Setting up cmdline for kdump kernel failed\n");
+			ret = -EINVAL;
+			goto out;
+		}
+		cmdline = modified_cmdline;
+	}
+
+	if (initrd != NULL) {
+		kbuf.buffer = initrd;
+		kbuf.bufsz = kbuf.memsz = initrd_len;
+		kbuf.buf_align = PAGE_SIZE;
+		kbuf.top_down = false;
+		kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
+		ret = kexec_add_buffer(&kbuf);
+		if (ret)
+			goto out;
+		initrd_load_addr = kbuf.mem;
+
+		kexec_dprintk("Loaded initrd at 0x%lx\n", initrd_load_addr);
+	}
+
+	ret = get_reserved_memory_ranges(&rmem);
+	if (ret)
+		goto out;
+
+	fdt = of_kexec_alloc_and_setup_fdt(image, initrd_load_addr,
+					   initrd_len, cmdline,
+					   kexec_extra_fdt_size_ppc64(image, rmem));
+	if (!fdt) {
+		pr_err("Error setting up the new device tree.\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = setup_new_fdt_ppc64(image, fdt, rmem);
+	if (ret)
+		goto out_free_fdt;
+
+	if (!IS_ENABLED(CONFIG_CRASH_HOTPLUG) || image->type != KEXEC_TYPE_CRASH)
+		fdt_pack(fdt);
+
+	kbuf.buffer = fdt;
+	kbuf.bufsz = kbuf.memsz = fdt_totalsize(fdt);
+	kbuf.buf_align = PAGE_SIZE;
+	kbuf.top_down = true;
+	kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
+	ret = kexec_add_buffer(&kbuf);
+	if (ret)
+		goto out_free_fdt;
+
+	/* FDT will be freed in arch_kimage_file_post_load_cleanup */
+	image->arch.fdt = fdt;
+
+	fdt_load_addr = kbuf.mem;
+
+	kexec_dprintk("Loaded device tree at 0x%lx\n", fdt_load_addr);
+
+	slave_code = elf_info.buffer + elf_info.proghdrs[0].p_offset;
+	ret = setup_purgatory_ppc64(image, slave_code, fdt, kernel_load_addr,
+				    fdt_load_addr);
+	if (ret)
+		pr_err("Error setting up the purgatory.\n");
+
+	goto out;
+
+out_free_fdt:
+	kvfree(fdt);
+out:
+	kfree(rmem);
+	kfree(modified_cmdline);
+	kexec_free_elf_info(&elf_info);
+
+	return ret ? ERR_PTR(ret) : NULL;
+}
+
+const struct kexec_file_ops kexec_elf64_ops = {
+	.probe = kexec_elf_probe,
+	.load = elf64_load,
+};

linux-7.2.3/arch/powerpc/kexec/file_load.c

@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * powerpc code to implement the kexec_file_load syscall
+ *
+ * Copyright (C) 2004  Adam Litke (agl@us.ibm.com)
+ * Copyright (C) 2004  IBM Corp.
+ * Copyright (C) 2004,2005  Milton D Miller II, IBM Corporation
+ * Copyright (C) 2005  R Sharada (sharada@in.ibm.com)
+ * Copyright (C) 2006  Mohan Kumar M (mohan@in.ibm.com)
+ * Copyright (C) 2016  IBM Corporation
+ *
+ * Based on kexec-tools' kexec-elf-ppc64.c, fs2dt.c.
+ * Heavily modified for the kernel by
+ * Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>.
+ */
+
+#include <linux/slab.h>
+#include <linux/kexec.h>
+#include <linux/of_fdt.h>
+#include <linux/libfdt.h>
+#include <asm/setup.h>
+
+#define SLAVE_CODE_SIZE		256	/* First 0x100 bytes */
+
+/**
+ * setup_kdump_cmdline - Prepend "elfcorehdr=<addr> " to command line
+ *                       of kdump kernel for exporting the core.
+ * @image:               Kexec image
+ * @cmdline:             Command line parameters to update.
+ * @cmdline_len:         Length of the cmdline parameters.
+ *
+ * kdump segment must be setup before calling this function.
+ *
+ * Returns new cmdline buffer for kdump kernel on success, NULL otherwise.
+ */
+char *setup_kdump_cmdline(struct kimage *image, char *cmdline,
+			  unsigned long cmdline_len)
+{
+	int elfcorehdr_strlen;
+	char *cmdline_ptr;
+
+	cmdline_ptr = kzalloc(COMMAND_LINE_SIZE, GFP_KERNEL);
+	if (!cmdline_ptr)
+		return NULL;
+
+	elfcorehdr_strlen = sprintf(cmdline_ptr, "elfcorehdr=0x%lx ",
+				    image->elf_load_addr);
+
+	if (elfcorehdr_strlen + cmdline_len > COMMAND_LINE_SIZE) {
+		pr_err("Appending elfcorehdr=<addr> exceeds cmdline size\n");
+		kfree(cmdline_ptr);
+		return NULL;
+	}
+
+	memcpy(cmdline_ptr + elfcorehdr_strlen, cmdline, cmdline_len);
+	// Ensure it's nul terminated
+	cmdline_ptr[COMMAND_LINE_SIZE - 1] = '\0';
+	return cmdline_ptr;
+}
+
+/**
+ * setup_purgatory - initialize the purgatory's global variables
+ * @image:		kexec image.
+ * @slave_code:		Slave code for the purgatory.
+ * @fdt:		Flattened device tree for the next kernel.
+ * @kernel_load_addr:	Address where the kernel is loaded.
+ * @fdt_load_addr:	Address where the flattened device tree is loaded.
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+int setup_purgatory(struct kimage *image, const void *slave_code,
+		    const void *fdt, unsigned long kernel_load_addr,
+		    unsigned long fdt_load_addr)
+{
+	unsigned int *slave_code_buf, master_entry;
+	int ret;
+
+	slave_code_buf = kmalloc(SLAVE_CODE_SIZE, GFP_KERNEL);
+	if (!slave_code_buf)
+		return -ENOMEM;
+
+	/* Get the slave code from the new kernel and put it in purgatory. */
+	ret = kexec_purgatory_get_set_symbol(image, "purgatory_start",
+					     slave_code_buf, SLAVE_CODE_SIZE,
+					     true);
+	if (ret) {
+		kfree(slave_code_buf);
+		return ret;
+	}
+
+	master_entry = slave_code_buf[0];
+	memcpy(slave_code_buf, slave_code, SLAVE_CODE_SIZE);
+	slave_code_buf[0] = master_entry;
+	ret = kexec_purgatory_get_set_symbol(image, "purgatory_start",
+					     slave_code_buf, SLAVE_CODE_SIZE,
+					     false);
+	kfree(slave_code_buf);
+
+	ret = kexec_purgatory_get_set_symbol(image, "kernel", &kernel_load_addr,
+					     sizeof(kernel_load_addr), false);
+	if (ret)
+		return ret;
+	ret = kexec_purgatory_get_set_symbol(image, "dt_offset", &fdt_load_addr,
+					     sizeof(fdt_load_addr), false);
+	if (ret)
+		return ret;
+
+	return 0;
+}

linux-7.2.3/arch/powerpc/kexec/file_load_64.c

@@ -0,0 +1,856 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ppc64 code to implement the kexec_file_load syscall
+ *
+ * Copyright (C) 2004  Adam Litke (agl@us.ibm.com)
+ * Copyright (C) 2004  IBM Corp.
+ * Copyright (C) 2004,2005  Milton D Miller II, IBM Corporation
+ * Copyright (C) 2005  R Sharada (sharada@in.ibm.com)
+ * Copyright (C) 2006  Mohan Kumar M (mohan@in.ibm.com)
+ * Copyright (C) 2020  IBM Corporation
+ *
+ * Based on kexec-tools' kexec-ppc64.c, kexec-elf-rel-ppc64.c, fs2dt.c.
+ * Heavily modified for the kernel by
+ * Hari Bathini, IBM Corporation.
+ */
+
+#include <linux/kexec.h>
+#include <linux/of_fdt.h>
+#include <linux/libfdt.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/memblock.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <asm/setup.h>
+#include <asm/drmem.h>
+#include <asm/firmware.h>
+#include <asm/kexec_ranges.h>
+#include <asm/crashdump-ppc64.h>
+#include <asm/mmzone.h>
+#include <asm/iommu.h>
+#include <asm/prom.h>
+#include <asm/plpks.h>
+#include <asm/cputhreads.h>
+
+struct umem_info {
+	__be64 *buf;		/* data buffer for usable-memory property */
+	u32 size;		/* size allocated for the data buffer */
+	u32 max_entries;	/* maximum no. of entries */
+	u32 idx;		/* index of current entry */
+
+	/* usable memory ranges to look up */
+	unsigned int nr_ranges;
+	const struct range *ranges;
+};
+
+const struct kexec_file_ops * const kexec_file_loaders[] = {
+	&kexec_elf64_ops,
+	NULL
+};
+
+int arch_check_excluded_range(struct kimage *image, unsigned long start,
+			      unsigned long end)
+{
+	struct crash_mem *emem;
+	int i;
+
+	emem = image->arch.exclude_ranges;
+	for (i = 0; i < emem->nr_ranges; i++)
+		if (start < emem->ranges[i].end && end > emem->ranges[i].start)
+			return 1;
+
+	return 0;
+}
+
+#ifdef CONFIG_CRASH_DUMP
+/**
+ * check_realloc_usable_mem - Reallocate buffer if it can't accommodate entries
+ * @um_info:                  Usable memory buffer and ranges info.
+ * @cnt:                      No. of entries to accommodate.
+ *
+ * Frees up the old buffer if memory reallocation fails.
+ *
+ * Returns buffer on success, NULL on error.
+ */
+static __be64 *check_realloc_usable_mem(struct umem_info *um_info, int cnt)
+{
+	u32 new_size;
+	__be64 *tbuf;
+
+	if ((um_info->idx + cnt) <= um_info->max_entries)
+		return um_info->buf;
+
+	new_size = um_info->size + MEM_RANGE_CHUNK_SZ;
+	tbuf = krealloc(um_info->buf, new_size, GFP_KERNEL);
+	if (tbuf) {
+		um_info->buf = tbuf;
+		um_info->size = new_size;
+		um_info->max_entries = (um_info->size / sizeof(u64));
+	}
+
+	return tbuf;
+}
+
+/**
+ * add_usable_mem - Add the usable memory ranges within the given memory range
+ *                  to the buffer
+ * @um_info:        Usable memory buffer and ranges info.
+ * @base:           Base address of memory range to look for.
+ * @end:            End address of memory range to look for.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+static int add_usable_mem(struct umem_info *um_info, u64 base, u64 end)
+{
+	u64 loc_base, loc_end;
+	bool add;
+	int i;
+
+	for (i = 0; i < um_info->nr_ranges; i++) {
+		add = false;
+		loc_base = um_info->ranges[i].start;
+		loc_end = um_info->ranges[i].end;
+		if (loc_base >= base && loc_end <= end)
+			add = true;
+		else if (base < loc_end && end > loc_base) {
+			if (loc_base < base)
+				loc_base = base;
+			if (loc_end > end)
+				loc_end = end;
+			add = true;
+		}
+
+		if (add) {
+			if (!check_realloc_usable_mem(um_info, 2))
+				return -ENOMEM;
+
+			um_info->buf[um_info->idx++] = cpu_to_be64(loc_base);
+			um_info->buf[um_info->idx++] =
+					cpu_to_be64(loc_end - loc_base + 1);
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * kdump_setup_usable_lmb - This is a callback function that gets called by
+ *                          walk_drmem_lmbs for every LMB to set its
+ *                          usable memory ranges.
+ * @lmb:                    LMB info.
+ * @usm:                    linux,drconf-usable-memory property value.
+ * @data:                   Pointer to usable memory buffer and ranges info.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+static int kdump_setup_usable_lmb(struct drmem_lmb *lmb, const __be32 **usm,
+				  void *data)
+{
+	struct umem_info *um_info;
+	int tmp_idx, ret;
+	u64 base, end;
+
+	/*
+	 * kdump load isn't supported on kernels already booted with
+	 * linux,drconf-usable-memory property.
+	 */
+	if (*usm) {
+		pr_err("linux,drconf-usable-memory property already exists!");
+		return -EINVAL;
+	}
+
+	um_info = data;
+	tmp_idx = um_info->idx;
+	if (!check_realloc_usable_mem(um_info, 1))
+		return -ENOMEM;
+
+	um_info->idx++;
+	base = lmb->base_addr;
+	end = base + drmem_lmb_size() - 1;
+	ret = add_usable_mem(um_info, base, end);
+	if (!ret) {
+		/*
+		 * Update the no. of ranges added. Two entries (base & size)
+		 * for every range added.
+		 */
+		um_info->buf[tmp_idx] =
+				cpu_to_be64((um_info->idx - tmp_idx - 1) / 2);
+	}
+
+	return ret;
+}
+
+#define NODE_PATH_LEN		256
+/**
+ * add_usable_mem_property - Add usable memory property for the given
+ *                           memory node.
+ * @fdt:                     Flattened device tree for the kdump kernel.
+ * @dn:                      Memory node.
+ * @um_info:                 Usable memory buffer and ranges info.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+static int add_usable_mem_property(void *fdt, struct device_node *dn,
+				   struct umem_info *um_info)
+{
+	int node;
+	char path[NODE_PATH_LEN];
+	int i, ret;
+	u64 base, size;
+
+	of_node_get(dn);
+
+	if (snprintf(path, NODE_PATH_LEN, "%pOF", dn) > (NODE_PATH_LEN - 1)) {
+		pr_err("Buffer (%d) too small for memory node: %pOF\n",
+		       NODE_PATH_LEN, dn);
+		return -EOVERFLOW;
+	}
+	kexec_dprintk("Memory node path: %s\n", path);
+
+	/* Now that we know the path, find its offset in kdump kernel's fdt */
+	node = fdt_path_offset(fdt, path);
+	if (node < 0) {
+		pr_err("Malformed device tree: error reading %s\n", path);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	um_info->idx  = 0;
+	if (!check_realloc_usable_mem(um_info, 2)) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	/*
+	 * "reg" property represents sequence of (addr,size) tuples
+	 * each representing a memory range.
+	 */
+	for (i = 0; ; i++) {
+		ret = of_property_read_reg(dn, i, &base, &size);
+		if (ret)
+			break;
+
+		ret = add_usable_mem(um_info, base, base + size - 1);
+		if (ret)
+			goto out;
+	}
+
+	// No reg or empty reg? Skip this node.
+	if (i == 0)
+		goto out;
+
+	/*
+	 * No kdump kernel usable memory found in this memory node.
+	 * Write (0,0) tuple in linux,usable-memory property for
+	 * this region to be ignored.
+	 */
+	if (um_info->idx == 0) {
+		um_info->buf[0] = 0;
+		um_info->buf[1] = 0;
+		um_info->idx = 2;
+	}
+
+	ret = fdt_setprop(fdt, node, "linux,usable-memory", um_info->buf,
+			  (um_info->idx * sizeof(u64)));
+
+out:
+	of_node_put(dn);
+	return ret;
+}
+
+
+/**
+ * update_usable_mem_fdt - Updates kdump kernel's fdt with linux,usable-memory
+ *                         and linux,drconf-usable-memory DT properties as
+ *                         appropriate to restrict its memory usage.
+ * @fdt:                   Flattened device tree for the kdump kernel.
+ * @usable_mem:            Usable memory ranges for kdump kernel.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+static int update_usable_mem_fdt(void *fdt, struct crash_mem *usable_mem)
+{
+	struct umem_info um_info;
+	struct device_node *dn;
+	int node, ret = 0;
+
+	if (!usable_mem) {
+		pr_err("Usable memory ranges for kdump kernel not found\n");
+		return -ENOENT;
+	}
+
+	node = fdt_path_offset(fdt, "/ibm,dynamic-reconfiguration-memory");
+	if (node == -FDT_ERR_NOTFOUND)
+		kexec_dprintk("No dynamic reconfiguration memory found\n");
+	else if (node < 0) {
+		pr_err("Malformed device tree: error reading /ibm,dynamic-reconfiguration-memory.\n");
+		return -EINVAL;
+	}
+
+	um_info.buf  = NULL;
+	um_info.size = 0;
+	um_info.max_entries = 0;
+	um_info.idx  = 0;
+	/* Memory ranges to look up */
+	um_info.ranges = &(usable_mem->ranges[0]);
+	um_info.nr_ranges = usable_mem->nr_ranges;
+
+	dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
+	if (dn) {
+		ret = walk_drmem_lmbs(dn, &um_info, kdump_setup_usable_lmb);
+		of_node_put(dn);
+
+		if (ret) {
+			pr_err("Could not setup linux,drconf-usable-memory property for kdump\n");
+			goto out;
+		}
+
+		ret = fdt_setprop(fdt, node, "linux,drconf-usable-memory",
+				  um_info.buf, (um_info.idx * sizeof(u64)));
+		if (ret) {
+			pr_err("Failed to update fdt with linux,drconf-usable-memory property: %s",
+			       fdt_strerror(ret));
+			goto out;
+		}
+	}
+
+	/*
+	 * Walk through each memory node and set linux,usable-memory property
+	 * for the corresponding node in kdump kernel's fdt.
+	 */
+	for_each_node_by_type(dn, "memory") {
+		ret = add_usable_mem_property(fdt, dn, &um_info);
+		if (ret) {
+			pr_err("Failed to set linux,usable-memory property for %s node",
+			       dn->full_name);
+			of_node_put(dn);
+			goto out;
+		}
+	}
+
+out:
+	kfree(um_info.buf);
+	return ret;
+}
+
+/**
+ * load_backup_segment - Locate a memory hole to place the backup region.
+ * @image:               Kexec image.
+ * @kbuf:                Buffer contents and memory parameters.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+static int load_backup_segment(struct kimage *image, struct kexec_buf *kbuf)
+{
+	void *buf;
+	int ret;
+
+	/*
+	 * Setup a source buffer for backup segment.
+	 *
+	 * A source buffer has no meaning for backup region as data will
+	 * be copied from backup source, after crash, in the purgatory.
+	 * But as load segment code doesn't recognize such segments,
+	 * setup a dummy source buffer to keep it happy for now.
+	 */
+	buf = vzalloc(BACKUP_SRC_SIZE);
+	if (!buf)
+		return -ENOMEM;
+
+	kbuf->buffer = buf;
+	kbuf->mem = KEXEC_BUF_MEM_UNKNOWN;
+	kbuf->bufsz = kbuf->memsz = BACKUP_SRC_SIZE;
+	kbuf->top_down = false;
+
+	ret = kexec_add_buffer(kbuf);
+	if (ret) {
+		vfree(buf);
+		return ret;
+	}
+
+	image->arch.backup_buf = buf;
+	image->arch.backup_start = kbuf->mem;
+	return 0;
+}
+
+static unsigned int kdump_extra_elfcorehdr_size(struct crash_mem *cmem)
+{
+#if defined(CONFIG_CRASH_HOTPLUG) && defined(CONFIG_MEMORY_HOTPLUG)
+	unsigned int extra_sz = 0;
+
+	if (CONFIG_CRASH_MAX_MEMORY_RANGES > (unsigned int)PN_XNUM)
+		pr_warn("Number of Phdrs %u exceeds max\n", CONFIG_CRASH_MAX_MEMORY_RANGES);
+	else if (cmem->nr_ranges >= CONFIG_CRASH_MAX_MEMORY_RANGES)
+		pr_warn("Configured crash mem ranges may not be enough\n");
+	else
+		extra_sz = (CONFIG_CRASH_MAX_MEMORY_RANGES - cmem->nr_ranges) * sizeof(Elf64_Phdr);
+
+	return extra_sz;
+#endif
+	return 0;
+}
+
+/**
+ * load_elfcorehdr_segment - Setup crash memory ranges and initialize elfcorehdr
+ *                           segment needed to load kdump kernel.
+ * @image:                   Kexec image.
+ * @kbuf:                    Buffer contents and memory parameters.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+static int load_elfcorehdr_segment(struct kimage *image, struct kexec_buf *kbuf)
+{
+	struct crash_mem *cmem = NULL;
+	unsigned long headers_sz;
+	void *headers = NULL;
+	int ret;
+
+	ret = get_crash_memory_ranges(&cmem);
+	if (ret)
+		goto out;
+
+	/* Setup elfcorehdr segment */
+	ret = crash_prepare_elf64_headers(cmem, false, &headers, &headers_sz);
+	if (ret) {
+		pr_err("Failed to prepare elf headers for the core\n");
+		goto out;
+	}
+
+	/* Fix the offset for backup region in the ELF header */
+	sync_backup_region_phdr(image, headers, false);
+
+	kbuf->buffer = headers;
+	kbuf->mem = KEXEC_BUF_MEM_UNKNOWN;
+	kbuf->bufsz = headers_sz;
+
+	/*
+	 * Account for extra space required to accommodate additional memory
+	 * ranges in elfcorehdr due to memory hotplug events.
+	 */
+	kbuf->memsz = headers_sz + kdump_extra_elfcorehdr_size(cmem);
+	kbuf->top_down = false;
+
+	ret = kexec_add_buffer(kbuf);
+	if (ret) {
+		vfree(headers);
+		goto out;
+	}
+
+	image->elf_load_addr = kbuf->mem;
+
+	/*
+	 * If CONFIG_CRASH_HOTPLUG is enabled, the elfcorehdr kexec segment
+	 * memsz can be larger than bufsz. Always initialize elf_headers_sz
+	 * with memsz. This ensures the correct size is reserved for elfcorehdr
+	 * memory in the FDT prepared for kdump.
+	 */
+	image->elf_headers_sz = kbuf->memsz;
+	image->elf_headers = headers;
+out:
+	kfree(cmem);
+	return ret;
+}
+
+/**
+ * load_crashdump_segments_ppc64 - Initialize the additional segements needed
+ *                                 to load kdump kernel.
+ * @image:                         Kexec image.
+ * @kbuf:                          Buffer contents and memory parameters.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+int load_crashdump_segments_ppc64(struct kimage *image,
+				  struct kexec_buf *kbuf)
+{
+	int ret;
+
+	/* Load backup segment - first 64K bytes of the crashing kernel */
+	ret = load_backup_segment(image, kbuf);
+	if (ret) {
+		pr_err("Failed to load backup segment\n");
+		return ret;
+	}
+	kexec_dprintk("Loaded the backup region at 0x%lx\n", kbuf->mem);
+
+	/* Load elfcorehdr segment - to export crashing kernel's vmcore */
+	ret = load_elfcorehdr_segment(image, kbuf);
+	if (ret) {
+		pr_err("Failed to load elfcorehdr segment\n");
+		return ret;
+	}
+	kexec_dprintk("Loaded elf core header at 0x%lx, bufsz=0x%lx memsz=0x%lx\n",
+		      image->elf_load_addr, kbuf->bufsz, kbuf->memsz);
+
+	return 0;
+}
+#endif
+
+/**
+ * setup_purgatory_ppc64 - initialize PPC64 specific purgatory's global
+ *                         variables and call setup_purgatory() to initialize
+ *                         common global variable.
+ * @image:                 kexec image.
+ * @slave_code:            Slave code for the purgatory.
+ * @fdt:                   Flattened device tree for the next kernel.
+ * @kernel_load_addr:      Address where the kernel is loaded.
+ * @fdt_load_addr:         Address where the flattened device tree is loaded.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+int setup_purgatory_ppc64(struct kimage *image, const void *slave_code,
+			  const void *fdt, unsigned long kernel_load_addr,
+			  unsigned long fdt_load_addr)
+{
+	struct device_node *dn = NULL;
+	int ret;
+
+	ret = setup_purgatory(image, slave_code, fdt, kernel_load_addr,
+			      fdt_load_addr);
+	if (ret)
+		goto out;
+
+	if (image->type == KEXEC_TYPE_CRASH) {
+		u32 my_run_at_load = 1;
+
+		/*
+		 * Tell relocatable kernel to run at load address
+		 * via the word meant for that at 0x5c.
+		 */
+		ret = kexec_purgatory_get_set_symbol(image, "run_at_load",
+						     &my_run_at_load,
+						     sizeof(my_run_at_load),
+						     false);
+		if (ret)
+			goto out;
+	}
+
+	/* Tell purgatory where to look for backup region */
+	ret = kexec_purgatory_get_set_symbol(image, "backup_start",
+					     &image->arch.backup_start,
+					     sizeof(image->arch.backup_start),
+					     false);
+	if (ret)
+		goto out;
+
+	/* Setup OPAL base & entry values */
+	dn = of_find_node_by_path("/ibm,opal");
+	if (dn) {
+		u64 val;
+
+		ret = of_property_read_u64(dn, "opal-base-address", &val);
+		if (ret)
+			goto out;
+
+		ret = kexec_purgatory_get_set_symbol(image, "opal_base", &val,
+						     sizeof(val), false);
+		if (ret)
+			goto out;
+
+		ret = of_property_read_u64(dn, "opal-entry-address", &val);
+		if (ret)
+			goto out;
+		ret = kexec_purgatory_get_set_symbol(image, "opal_entry", &val,
+						     sizeof(val), false);
+	}
+out:
+	if (ret)
+		pr_err("Failed to setup purgatory symbols");
+	of_node_put(dn);
+	return ret;
+}
+
+/**
+ * cpu_node_size - Compute the size of a CPU node in the FDT.
+ *                 This should be done only once and the value is stored in
+ *                 a static variable.
+ * Returns the max size of a CPU node in the FDT.
+ */
+static unsigned int cpu_node_size(void)
+{
+	static unsigned int size;
+	struct device_node *dn;
+	struct property *pp;
+
+	/*
+	 * Don't compute it twice, we are assuming that the per CPU node size
+	 * doesn't change during the system's life.
+	 */
+	if (size)
+		return size;
+
+	dn = of_find_node_by_type(NULL, "cpu");
+	if (WARN_ON_ONCE(!dn)) {
+		// Unlikely to happen
+		return 0;
+	}
+
+	/*
+	 * We compute the sub node size for a CPU node, assuming it
+	 * will be the same for all.
+	 */
+	size += strlen(dn->name) + 5;
+	for_each_property_of_node(dn, pp) {
+		size += strlen(pp->name);
+		size += pp->length;
+	}
+
+	of_node_put(dn);
+	return size;
+}
+
+static unsigned int kdump_extra_fdt_size_ppc64(struct kimage *image, unsigned int cpu_nodes)
+{
+	unsigned int extra_size = 0;
+	u64 usm_entries;
+#ifdef CONFIG_CRASH_HOTPLUG
+	unsigned int possible_cpu_nodes;
+#endif
+
+	if (!IS_ENABLED(CONFIG_CRASH_DUMP) || image->type != KEXEC_TYPE_CRASH)
+		return 0;
+
+	/*
+	 * For kdump kernel, account for linux,usable-memory and
+	 * linux,drconf-usable-memory properties. Get an approximate on the
+	 * number of usable memory entries and use for FDT size estimation.
+	 */
+	if (drmem_lmb_size()) {
+		usm_entries = ((memory_hotplug_max() / drmem_lmb_size()) +
+			       (2 * (resource_size(&crashk_res) / drmem_lmb_size())));
+		extra_size += (unsigned int)(usm_entries * sizeof(u64));
+	}
+
+#ifdef CONFIG_CRASH_HOTPLUG
+	/*
+	 * Make sure enough space is reserved to accommodate possible CPU nodes
+	 * in the crash FDT. This allows packing possible CPU nodes which are
+	 * not yet present in the system without regenerating the entire FDT.
+	 */
+	if (image->type == KEXEC_TYPE_CRASH) {
+		possible_cpu_nodes = num_possible_cpus() / threads_per_core;
+		if (possible_cpu_nodes > cpu_nodes)
+			extra_size += (possible_cpu_nodes - cpu_nodes) * cpu_node_size();
+	}
+#endif
+
+	return extra_size;
+}
+
+/**
+ * kexec_extra_fdt_size_ppc64 - Return the estimated additional size needed to
+ *                              setup FDT for kexec/kdump kernel.
+ * @image:                      kexec image being loaded.
+ *
+ * Returns the estimated extra size needed for kexec/kdump kernel FDT.
+ */
+unsigned int kexec_extra_fdt_size_ppc64(struct kimage *image, struct crash_mem *rmem)
+{
+	struct device_node *dn;
+	unsigned int cpu_nodes = 0, extra_size = 0;
+
+	// Budget some space for the password blob. There's already extra space
+	// for the key name
+	if (plpks_is_available())
+		extra_size += (unsigned int)plpks_get_passwordlen();
+
+	/* Get the number of CPU nodes in the current device tree */
+	for_each_node_by_type(dn, "cpu") {
+		cpu_nodes++;
+	}
+
+	/* Consider extra space for CPU nodes added since the boot time */
+	if (cpu_nodes > boot_cpu_node_count)
+		extra_size += (cpu_nodes - boot_cpu_node_count) * cpu_node_size();
+
+	/* Consider extra space for reserved memory ranges if any */
+	if (rmem->nr_ranges > 0)
+		extra_size += sizeof(struct fdt_reserve_entry) * rmem->nr_ranges;
+
+	return extra_size + kdump_extra_fdt_size_ppc64(image, cpu_nodes);
+}
+
+static int copy_property(void *fdt, int node_offset, const struct device_node *dn,
+			 const char *propname)
+{
+	const void *prop, *fdtprop;
+	int len = 0, fdtlen = 0;
+
+	prop = of_get_property(dn, propname, &len);
+	fdtprop = fdt_getprop(fdt, node_offset, propname, &fdtlen);
+
+	if (fdtprop && !prop)
+		return fdt_delprop(fdt, node_offset, propname);
+	else if (prop)
+		return fdt_setprop(fdt, node_offset, propname, prop, len);
+	else
+		return -FDT_ERR_NOTFOUND;
+}
+
+static int update_pci_dma_nodes(void *fdt, const char *dmapropname)
+{
+	struct device_node *dn;
+	int pci_offset, root_offset, ret = 0;
+
+	if (!firmware_has_feature(FW_FEATURE_LPAR))
+		return 0;
+
+	root_offset = fdt_path_offset(fdt, "/");
+	for_each_node_with_property(dn, dmapropname) {
+		pci_offset = fdt_subnode_offset(fdt, root_offset, of_node_full_name(dn));
+		if (pci_offset < 0)
+			continue;
+
+		ret = copy_property(fdt, pci_offset, dn, "ibm,dma-window");
+		if (ret < 0) {
+			of_node_put(dn);
+			break;
+		}
+		ret = copy_property(fdt, pci_offset, dn, dmapropname);
+		if (ret < 0) {
+			of_node_put(dn);
+			break;
+		}
+	}
+
+	return ret;
+}
+
+/**
+ * setup_new_fdt_ppc64 - Update the flattend device-tree of the kernel
+ *                       being loaded.
+ * @image:               kexec image being loaded.
+ * @fdt:                 Flattened device tree for the next kernel.
+ * @rmem:                Reserved memory ranges.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+int setup_new_fdt_ppc64(const struct kimage *image, void *fdt, struct crash_mem *rmem)
+{
+	struct crash_mem *umem = NULL;
+	int i, nr_ranges, ret;
+
+#ifdef CONFIG_CRASH_DUMP
+	/*
+	 * Restrict memory usage for kdump kernel by setting up
+	 * usable memory ranges and memory reserve map.
+	 */
+	if (image->type == KEXEC_TYPE_CRASH) {
+		ret = get_usable_memory_ranges(&umem);
+		if (ret)
+			goto out;
+
+		ret = update_usable_mem_fdt(fdt, umem);
+		if (ret) {
+			pr_err("Error setting up usable-memory property for kdump kernel\n");
+			goto out;
+		}
+
+		/*
+		 * Ensure we don't touch crashed kernel's memory except the
+		 * first 64K of RAM, which will be backed up.
+		 */
+		ret = fdt_add_mem_rsv(fdt, BACKUP_SRC_END + 1,
+				      crashk_res.start - BACKUP_SRC_SIZE);
+		if (ret) {
+			pr_err("Error reserving crash memory: %s\n",
+			       fdt_strerror(ret));
+			goto out;
+		}
+
+		/* Ensure backup region is not used by kdump/capture kernel */
+		ret = fdt_add_mem_rsv(fdt, image->arch.backup_start,
+				      BACKUP_SRC_SIZE);
+		if (ret) {
+			pr_err("Error reserving memory for backup: %s\n",
+			       fdt_strerror(ret));
+			goto out;
+		}
+	}
+#endif
+
+	/* Update cpus nodes information to account hotplug CPUs. */
+	ret =  update_cpus_node(fdt);
+	if (ret < 0)
+		goto out;
+
+	ret = update_pci_dma_nodes(fdt, DIRECT64_PROPNAME);
+	if (ret < 0)
+		goto out;
+
+	ret = update_pci_dma_nodes(fdt, DMA64_PROPNAME);
+	if (ret < 0)
+		goto out;
+
+	/* Update memory reserve map */
+	nr_ranges = rmem ? rmem->nr_ranges : 0;
+	for (i = 0; i < nr_ranges; i++) {
+		u64 base, size;
+
+		base = rmem->ranges[i].start;
+		size = rmem->ranges[i].end - base + 1;
+		ret = fdt_add_mem_rsv(fdt, base, size);
+		if (ret) {
+			pr_err("Error updating memory reserve map: %s\n",
+			       fdt_strerror(ret));
+			goto out;
+		}
+	}
+
+	// If we have PLPKS active, we need to provide the password to the new kernel
+	if (plpks_is_available())
+		ret = plpks_populate_fdt(fdt);
+
+out:
+	kfree(umem);
+	return ret;
+}
+
+/**
+ * arch_kexec_kernel_image_probe - Does additional handling needed to setup
+ *                                 kexec segments.
+ * @image:                         kexec image being loaded.
+ * @buf:                           Buffer pointing to elf data.
+ * @buf_len:                       Length of the buffer.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
+				  unsigned long buf_len)
+{
+	int ret;
+
+	/* Get exclude memory ranges needed for setting up kexec segments */
+	ret = get_exclude_memory_ranges(&(image->arch.exclude_ranges));
+	if (ret) {
+		pr_err("Failed to setup exclude memory ranges for buffer lookup\n");
+		return ret;
+	}
+
+	return kexec_image_probe_default(image, buf, buf_len);
+}
+
+/**
+ * arch_kimage_file_post_load_cleanup - Frees up all the allocations done
+ *                                      while loading the image.
+ * @image:                              kexec image being loaded.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+int arch_kimage_file_post_load_cleanup(struct kimage *image)
+{
+	kfree(image->arch.exclude_ranges);
+	image->arch.exclude_ranges = NULL;
+
+	vfree(image->arch.backup_buf);
+	image->arch.backup_buf = NULL;
+
+	vfree(image->elf_headers);
+	image->elf_headers = NULL;
+	image->elf_headers_sz = 0;
+
+	kvfree(image->arch.fdt);
+	image->arch.fdt = NULL;
+
+	return kexec_image_post_load_cleanup_default(image);
+}

linux-7.2.3/arch/powerpc/kexec/ranges.c

@@ -0,0 +1,729 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * powerpc code to implement the kexec_file_load syscall
+ *
+ * Copyright (C) 2004  Adam Litke (agl@us.ibm.com)
+ * Copyright (C) 2004  IBM Corp.
+ * Copyright (C) 2004,2005  Milton D Miller II, IBM Corporation
+ * Copyright (C) 2005  R Sharada (sharada@in.ibm.com)
+ * Copyright (C) 2006  Mohan Kumar M (mohan@in.ibm.com)
+ * Copyright (C) 2020  IBM Corporation
+ *
+ * Based on kexec-tools' kexec-ppc64.c, fs2dt.c.
+ * Heavily modified for the kernel by
+ * Hari Bathini, IBM Corporation.
+ */
+
+#define pr_fmt(fmt) "kexec ranges: " fmt
+
+#include <linux/sort.h>
+#include <linux/kexec.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/memblock.h>
+#include <linux/crash_core.h>
+#include <asm/sections.h>
+#include <asm/kexec_ranges.h>
+#include <asm/crashdump-ppc64.h>
+
+#if defined(CONFIG_KEXEC_FILE) || defined(CONFIG_CRASH_DUMP)
+/**
+ * get_max_nr_ranges - Get the max no. of ranges crash_mem structure
+ *                     could hold, given the size allocated for it.
+ * @size:              Allocation size of crash_mem structure.
+ *
+ * Returns the maximum no. of ranges.
+ */
+static inline unsigned int get_max_nr_ranges(size_t size)
+{
+	return ((size - sizeof(struct crash_mem)) /
+		sizeof(struct range));
+}
+
+/**
+ * get_mem_rngs_size - Get the allocated size of mem_rngs based on
+ *                     max_nr_ranges and chunk size.
+ * @mem_rngs:          Memory ranges.
+ *
+ * Returns the maximum size of @mem_rngs.
+ */
+static inline size_t get_mem_rngs_size(struct crash_mem *mem_rngs)
+{
+	size_t size;
+
+	if (!mem_rngs)
+		return 0;
+
+	size = (sizeof(struct crash_mem) +
+		(mem_rngs->max_nr_ranges * sizeof(struct range)));
+
+	/*
+	 * Memory is allocated in size multiple of MEM_RANGE_CHUNK_SZ.
+	 * So, align to get the actual length.
+	 */
+	return ALIGN(size, MEM_RANGE_CHUNK_SZ);
+}
+
+/**
+ * __add_mem_range - add a memory range to memory ranges list.
+ * @mem_ranges:      Range list to add the memory range to.
+ * @base:            Base address of the range to add.
+ * @size:            Size of the memory range to add.
+ *
+ * (Re)allocates memory, if needed.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+static int __add_mem_range(struct crash_mem **mem_ranges, u64 base, u64 size)
+{
+	struct crash_mem *mem_rngs = *mem_ranges;
+
+	if (!mem_rngs || (mem_rngs->nr_ranges == mem_rngs->max_nr_ranges)) {
+		mem_rngs = realloc_mem_ranges(mem_ranges);
+		if (!mem_rngs)
+			return -ENOMEM;
+	}
+
+	mem_rngs->ranges[mem_rngs->nr_ranges].start = base;
+	mem_rngs->ranges[mem_rngs->nr_ranges].end = base + size - 1;
+	pr_debug("Added memory range [%#016llx - %#016llx] at index %d\n",
+		 base, base + size - 1, mem_rngs->nr_ranges);
+	mem_rngs->nr_ranges++;
+	return 0;
+}
+
+/**
+ * __merge_memory_ranges - Merges the given memory ranges list.
+ * @mem_rngs:              Range list to merge.
+ *
+ * Assumes a sorted range list.
+ *
+ * Returns nothing.
+ */
+static void __merge_memory_ranges(struct crash_mem *mem_rngs)
+{
+	struct range *ranges;
+	int i, idx;
+
+	if (!mem_rngs)
+		return;
+
+	idx = 0;
+	ranges = &(mem_rngs->ranges[0]);
+	for (i = 1; i < mem_rngs->nr_ranges; i++) {
+		if (ranges[i].start <= (ranges[i-1].end + 1))
+			ranges[idx].end = ranges[i].end;
+		else {
+			idx++;
+			if (i == idx)
+				continue;
+
+			ranges[idx] = ranges[i];
+		}
+	}
+	mem_rngs->nr_ranges = idx + 1;
+}
+
+/* cmp_func_t callback to sort ranges with sort() */
+static int rngcmp(const void *_x, const void *_y)
+{
+	const struct range *x = _x, *y = _y;
+
+	if (x->start > y->start)
+		return 1;
+	if (x->start < y->start)
+		return -1;
+	return 0;
+}
+
+/**
+ * sort_memory_ranges - Sorts the given memory ranges list.
+ * @mem_rngs:           Range list to sort.
+ * @merge:              If true, merge the list after sorting.
+ *
+ * Returns nothing.
+ */
+void sort_memory_ranges(struct crash_mem *mem_rngs, bool merge)
+{
+	int i;
+
+	if (!mem_rngs)
+		return;
+
+	/* Sort the ranges in-place */
+	sort(&(mem_rngs->ranges[0]), mem_rngs->nr_ranges,
+	     sizeof(mem_rngs->ranges[0]), rngcmp, NULL);
+
+	if (merge)
+		__merge_memory_ranges(mem_rngs);
+
+	/* For debugging purpose */
+	pr_debug("Memory ranges:\n");
+	for (i = 0; i < mem_rngs->nr_ranges; i++) {
+		pr_debug("\t[%03d][%#016llx - %#016llx]\n", i,
+			 mem_rngs->ranges[i].start,
+			 mem_rngs->ranges[i].end);
+	}
+}
+
+/**
+ * realloc_mem_ranges - reallocate mem_ranges with size incremented
+ *                      by MEM_RANGE_CHUNK_SZ. Frees up the old memory,
+ *                      if memory allocation fails.
+ * @mem_ranges:         Memory ranges to reallocate.
+ *
+ * Returns pointer to reallocated memory on success, NULL otherwise.
+ */
+struct crash_mem *realloc_mem_ranges(struct crash_mem **mem_ranges)
+{
+	struct crash_mem *mem_rngs = *mem_ranges;
+	unsigned int nr_ranges;
+	size_t size;
+
+	size = get_mem_rngs_size(mem_rngs);
+	nr_ranges = mem_rngs ? mem_rngs->nr_ranges : 0;
+
+	size += MEM_RANGE_CHUNK_SZ;
+	mem_rngs = krealloc(*mem_ranges, size, GFP_KERNEL);
+	if (!mem_rngs) {
+		kfree(*mem_ranges);
+		*mem_ranges = NULL;
+		return NULL;
+	}
+
+	mem_rngs->nr_ranges = nr_ranges;
+	mem_rngs->max_nr_ranges = get_max_nr_ranges(size);
+	*mem_ranges = mem_rngs;
+
+	return mem_rngs;
+}
+
+/**
+ * add_mem_range - Updates existing memory range, if there is an overlap.
+ *                 Else, adds a new memory range.
+ * @mem_ranges:    Range list to add the memory range to.
+ * @base:          Base address of the range to add.
+ * @size:          Size of the memory range to add.
+ *
+ * (Re)allocates memory, if needed.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+int add_mem_range(struct crash_mem **mem_ranges, u64 base, u64 size)
+{
+	struct crash_mem *mem_rngs = *mem_ranges;
+	u64 mstart, mend, end;
+	unsigned int i;
+
+	if (!size)
+		return 0;
+
+	end = base + size - 1;
+
+	if (!mem_rngs || !(mem_rngs->nr_ranges))
+		return __add_mem_range(mem_ranges, base, size);
+
+	for (i = 0; i < mem_rngs->nr_ranges; i++) {
+		mstart = mem_rngs->ranges[i].start;
+		mend = mem_rngs->ranges[i].end;
+		if (base < mend && end > mstart) {
+			if (base < mstart)
+				mem_rngs->ranges[i].start = base;
+			if (end > mend)
+				mem_rngs->ranges[i].end = end;
+			return 0;
+		}
+	}
+
+	return __add_mem_range(mem_ranges, base, size);
+}
+
+#endif /* CONFIG_KEXEC_FILE || CONFIG_CRASH_DUMP */
+
+#ifdef CONFIG_KEXEC_FILE
+/**
+ * add_tce_mem_ranges - Adds tce-table range to the given memory ranges list.
+ * @mem_ranges:         Range list to add the memory range(s) to.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+static int add_tce_mem_ranges(struct crash_mem **mem_ranges)
+{
+	struct device_node *dn = NULL;
+	int ret = 0;
+
+	for_each_node_by_type(dn, "pci") {
+		u64 base;
+		u32 size;
+
+		ret = of_property_read_u64(dn, "linux,tce-base", &base);
+		ret |= of_property_read_u32(dn, "linux,tce-size", &size);
+		if (ret) {
+			/*
+			 * It is ok to have pci nodes without tce. So, ignore
+			 * property does not exist error.
+			 */
+			if (ret == -EINVAL) {
+				ret = 0;
+				continue;
+			}
+			break;
+		}
+
+		ret = add_mem_range(mem_ranges, base, size);
+		if (ret)
+			break;
+	}
+
+	of_node_put(dn);
+	return ret;
+}
+
+/**
+ * add_initrd_mem_range - Adds initrd range to the given memory ranges list,
+ *                        if the initrd was retained.
+ * @mem_ranges:           Range list to add the memory range to.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+static int add_initrd_mem_range(struct crash_mem **mem_ranges)
+{
+	u64 base, end;
+	int ret;
+
+	/* This range means something, only if initrd was retained */
+	if (!strstr(saved_command_line, "retain_initrd"))
+		return 0;
+
+	ret = of_property_read_u64(of_chosen, "linux,initrd-start", &base);
+	ret |= of_property_read_u64(of_chosen, "linux,initrd-end", &end);
+	if (!ret)
+		ret = add_mem_range(mem_ranges, base, end - base + 1);
+
+	return ret;
+}
+
+/**
+ * add_htab_mem_range - Adds htab range to the given memory ranges list,
+ *                      if it exists
+ * @mem_ranges:         Range list to add the memory range to.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+static int add_htab_mem_range(struct crash_mem **mem_ranges)
+{
+
+#ifdef CONFIG_PPC_64S_HASH_MMU
+	if (!htab_address)
+		return 0;
+
+	return add_mem_range(mem_ranges, __pa(htab_address), htab_size_bytes);
+#else
+	return 0;
+#endif
+}
+
+/**
+ * add_kernel_mem_range - Adds kernel text region to the given
+ *                        memory ranges list.
+ * @mem_ranges:           Range list to add the memory range to.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+static int add_kernel_mem_range(struct crash_mem **mem_ranges)
+{
+	return add_mem_range(mem_ranges, 0, __pa(_end));
+}
+#endif /* CONFIG_KEXEC_FILE */
+
+#if defined(CONFIG_KEXEC_FILE) || defined(CONFIG_CRASH_DUMP)
+/**
+ * add_rtas_mem_range - Adds RTAS region to the given memory ranges list.
+ * @mem_ranges:         Range list to add the memory range to.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+static int add_rtas_mem_range(struct crash_mem **mem_ranges)
+{
+	struct device_node *dn;
+	u32 base, size;
+	int ret = 0;
+
+	dn = of_find_node_by_path("/rtas");
+	if (!dn)
+		return 0;
+
+	ret = of_property_read_u32(dn, "linux,rtas-base", &base);
+	ret |= of_property_read_u32(dn, "rtas-size", &size);
+	if (!ret)
+		ret = add_mem_range(mem_ranges, base, size);
+
+	of_node_put(dn);
+	return ret;
+}
+
+/**
+ * add_opal_mem_range - Adds OPAL region to the given memory ranges list.
+ * @mem_ranges:         Range list to add the memory range to.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+static int add_opal_mem_range(struct crash_mem **mem_ranges)
+{
+	struct device_node *dn;
+	u64 base, size;
+	int ret;
+
+	dn = of_find_node_by_path("/ibm,opal");
+	if (!dn)
+		return 0;
+
+	ret = of_property_read_u64(dn, "opal-base-address", &base);
+	ret |= of_property_read_u64(dn, "opal-runtime-size", &size);
+	if (!ret)
+		ret = add_mem_range(mem_ranges, base, size);
+
+	of_node_put(dn);
+	return ret;
+}
+#endif /* CONFIG_KEXEC_FILE || CONFIG_CRASH_DUMP */
+
+#ifdef CONFIG_KEXEC_FILE
+/**
+ * add_reserved_mem_ranges - Adds "/reserved-ranges" regions exported by f/w
+ *                           to the given memory ranges list.
+ * @mem_ranges:              Range list to add the memory ranges to.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+static int add_reserved_mem_ranges(struct crash_mem **mem_ranges)
+{
+	int n_mem_addr_cells, n_mem_size_cells, i, len, cells, ret = 0;
+	struct device_node *root = of_find_node_by_path("/");
+	const __be32 *prop;
+
+	prop = of_get_property(root, "reserved-ranges", &len);
+	n_mem_addr_cells = of_n_addr_cells(root);
+	n_mem_size_cells = of_n_size_cells(root);
+	of_node_put(root);
+	if (!prop)
+		return 0;
+
+	cells = n_mem_addr_cells + n_mem_size_cells;
+
+	/* Each reserved range is an (address,size) pair */
+	for (i = 0; i < (len / (sizeof(u32) * cells)); i++) {
+		u64 base, size;
+
+		base = of_read_number(prop + (i * cells), n_mem_addr_cells);
+		size = of_read_number(prop + (i * cells) + n_mem_addr_cells,
+				      n_mem_size_cells);
+
+		ret = add_mem_range(mem_ranges, base, size);
+		if (ret)
+			break;
+	}
+
+	return ret;
+}
+
+/**
+ * get_reserved_memory_ranges - Get reserve memory ranges. This list includes
+ *                              memory regions that should be added to the
+ *                              memory reserve map to ensure the region is
+ *                              protected from any mischief.
+ * @mem_ranges:                 Range list to add the memory ranges to.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+int get_reserved_memory_ranges(struct crash_mem **mem_ranges)
+{
+	int ret;
+
+	ret = add_rtas_mem_range(mem_ranges);
+	if (ret)
+		goto out;
+
+	ret = add_tce_mem_ranges(mem_ranges);
+	if (ret)
+		goto out;
+
+	ret = add_reserved_mem_ranges(mem_ranges);
+out:
+	if (ret)
+		pr_err("Failed to setup reserved memory ranges\n");
+	return ret;
+}
+
+/**
+ * get_exclude_memory_ranges - Get exclude memory ranges. This list includes
+ *                             regions like opal/rtas, tce-table, initrd,
+ *                             kernel, htab which should be avoided while
+ *                             setting up kexec load segments.
+ * @mem_ranges:                Range list to add the memory ranges to.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+int get_exclude_memory_ranges(struct crash_mem **mem_ranges)
+{
+	int ret;
+
+	ret = add_tce_mem_ranges(mem_ranges);
+	if (ret)
+		goto out;
+
+	ret = add_initrd_mem_range(mem_ranges);
+	if (ret)
+		goto out;
+
+	ret = add_htab_mem_range(mem_ranges);
+	if (ret)
+		goto out;
+
+	ret = add_kernel_mem_range(mem_ranges);
+	if (ret)
+		goto out;
+
+	ret = add_rtas_mem_range(mem_ranges);
+	if (ret)
+		goto out;
+
+	ret = add_opal_mem_range(mem_ranges);
+	if (ret)
+		goto out;
+
+	ret = add_reserved_mem_ranges(mem_ranges);
+	if (ret)
+		goto out;
+
+	/* exclude memory ranges should be sorted for easy lookup */
+	sort_memory_ranges(*mem_ranges, true);
+out:
+	if (ret)
+		pr_err("Failed to setup exclude memory ranges\n");
+	return ret;
+}
+
+#ifdef CONFIG_CRASH_DUMP
+/**
+ * get_usable_memory_ranges - Get usable memory ranges. This list includes
+ *                            regions like crashkernel, opal/rtas & tce-table,
+ *                            that kdump kernel could use.
+ * @mem_ranges:               Range list to add the memory ranges to.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+int get_usable_memory_ranges(struct crash_mem **mem_ranges)
+{
+	int ret, i;
+
+	/*
+	 * Early boot failure observed on guests when low memory (first memory
+	 * block?) is not added to usable memory. So, add [0, crashk_res.end]
+	 * instead of [crashk_res.start, crashk_res.end] to workaround it.
+	 * Also, crashed kernel's memory must be added to reserve map to
+	 * avoid kdump kernel from using it.
+	 */
+	ret = add_mem_range(mem_ranges, 0, crashk_res.end + 1);
+	if (ret)
+		goto out;
+
+	for (i = 0; i < crashk_cma_cnt; i++) {
+		ret = add_mem_range(mem_ranges, crashk_cma_ranges[i].start,
+				    crashk_cma_ranges[i].end - crashk_cma_ranges[i].start + 1);
+		if (ret)
+			goto out;
+	}
+
+	ret = add_rtas_mem_range(mem_ranges);
+	if (ret)
+		goto out;
+
+	ret = add_opal_mem_range(mem_ranges);
+	if (ret)
+		goto out;
+
+	ret = add_tce_mem_ranges(mem_ranges);
+out:
+	if (ret)
+		pr_err("Failed to setup usable memory ranges\n");
+	return ret;
+}
+#endif /* CONFIG_CRASH_DUMP */
+#endif /* CONFIG_KEXEC_FILE */
+
+#ifdef CONFIG_CRASH_DUMP
+static int crash_exclude_mem_range_guarded(struct crash_mem **mem_ranges,
+					   unsigned long long mstart,
+					   unsigned long long mend)
+{
+	struct crash_mem *tmem = *mem_ranges;
+
+	/* Reallocate memory ranges if there is no space to split ranges */
+	if (tmem && (tmem->nr_ranges == tmem->max_nr_ranges)) {
+		tmem = realloc_mem_ranges(mem_ranges);
+		if (!tmem)
+			return -ENOMEM;
+	}
+
+	return crash_exclude_mem_range(tmem, mstart, mend);
+}
+
+/**
+ * get_crash_memory_ranges - Get crash memory ranges. This list includes
+ *                           first/crashing kernel's memory regions that
+ *                           would be exported via an elfcore.
+ * @mem_ranges:              Range list to add the memory ranges to.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+int get_crash_memory_ranges(struct crash_mem **mem_ranges)
+{
+	phys_addr_t base, end;
+	u64 i;
+	int ret;
+
+	for_each_mem_range(i, &base, &end) {
+		u64 size = end - base;
+
+		/* Skip backup memory region, which needs a separate entry */
+		if (base == BACKUP_SRC_START) {
+			if (size > BACKUP_SRC_SIZE) {
+				base = BACKUP_SRC_END + 1;
+				size -= BACKUP_SRC_SIZE;
+			} else
+				continue;
+		}
+
+		ret = add_mem_range(mem_ranges, base, size);
+		if (ret)
+			goto out;
+
+		/* Try merging adjacent ranges before reallocation attempt */
+		if ((*mem_ranges)->nr_ranges == (*mem_ranges)->max_nr_ranges)
+			sort_memory_ranges(*mem_ranges, true);
+	}
+
+	/* Exclude crashkernel region */
+	ret = crash_exclude_mem_range_guarded(mem_ranges, crashk_res.start, crashk_res.end);
+	if (ret)
+		goto out;
+
+	for (i = 0; i < crashk_cma_cnt; ++i) {
+		ret = crash_exclude_mem_range_guarded(mem_ranges, crashk_cma_ranges[i].start,
+					      crashk_cma_ranges[i].end);
+		if (ret)
+			goto out;
+	}
+
+	/*
+	 * FIXME: For now, stay in parity with kexec-tools but if RTAS/OPAL
+	 *        regions are exported to save their context at the time of
+	 *        crash, they should actually be backed up just like the
+	 *        first 64K bytes of memory.
+	 */
+	ret = add_rtas_mem_range(mem_ranges);
+	if (ret)
+		goto out;
+
+	ret = add_opal_mem_range(mem_ranges);
+	if (ret)
+		goto out;
+
+	/* create a separate program header for the backup region */
+	ret = add_mem_range(mem_ranges, BACKUP_SRC_START, BACKUP_SRC_SIZE);
+	if (ret)
+		goto out;
+
+	sort_memory_ranges(*mem_ranges, false);
+out:
+	if (ret)
+		pr_err("Failed to setup crash memory ranges\n");
+	return ret;
+}
+
+/**
+ * remove_mem_range - Removes the given memory range from the range list.
+ * @mem_ranges:    Range list to remove the memory range to.
+ * @base:          Base address of the range to remove.
+ * @size:          Size of the memory range to remove.
+ *
+ * (Re)allocates memory, if needed.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+int remove_mem_range(struct crash_mem **mem_ranges, u64 base, u64 size)
+{
+	u64 end;
+	int ret = 0;
+	unsigned int i;
+	u64 mstart, mend;
+	struct crash_mem *mem_rngs = *mem_ranges;
+
+	if (!size)
+		return 0;
+
+	/*
+	 * Memory range are stored as start and end address, use
+	 * the same format to do remove operation.
+	 */
+	end = base + size - 1;
+
+	for (i = 0; i < mem_rngs->nr_ranges; i++) {
+		mstart = mem_rngs->ranges[i].start;
+		mend = mem_rngs->ranges[i].end;
+
+		/*
+		 * Memory range to remove is not part of this range entry
+		 * in the memory range list
+		 */
+		if (!(base >= mstart && end <= mend))
+			continue;
+
+		/*
+		 * Memory range to remove is equivalent to this entry in the
+		 * memory range list. Remove the range entry from the list.
+		 */
+		if (base == mstart && end == mend) {
+			for (; i < mem_rngs->nr_ranges - 1; i++) {
+				mem_rngs->ranges[i].start = mem_rngs->ranges[i+1].start;
+				mem_rngs->ranges[i].end = mem_rngs->ranges[i+1].end;
+			}
+			mem_rngs->nr_ranges--;
+			goto out;
+		}
+		/*
+		 * Start address of the memory range to remove and the
+		 * current memory range entry in the list is same. Just
+		 * move the start address of the current memory range
+		 * entry in the list to end + 1.
+		 */
+		else if (base == mstart) {
+			mem_rngs->ranges[i].start = end + 1;
+			goto out;
+		}
+		/*
+		 * End address of the memory range to remove and the
+		 * current memory range entry in the list is same.
+		 * Just move the end address of the current memory
+		 * range entry in the list to base - 1.
+		 */
+		else if (end == mend)  {
+			mem_rngs->ranges[i].end = base - 1;
+			goto out;
+		}
+		/*
+		 * Memory range to remove is not at the edge of current
+		 * memory range entry. Split the current memory entry into
+		 * two half.
+		 */
+		else {
+			size = mem_rngs->ranges[i].end - end + 1;
+			mem_rngs->ranges[i].end = base - 1;
+			ret = add_mem_range(mem_ranges, end + 1, size);
+		}
+	}
+out:
+	return ret;
+}
+#endif /* CONFIG_CRASH_DUMP */

linux-7.2.3/arch/powerpc/kexec/relocate_32.S

@@ -0,0 +1,499 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * This file contains kexec low-level functions.
+ *
+ * Copyright (C) 2002-2003 Eric Biederman  <ebiederm@xmission.com>
+ * GameCube/ppc32 port Copyright (C) 2004 Albert Herranz
+ * PPC44x port. Copyright (C) 2011,  IBM Corporation
+ * 		Author: Suzuki Poulose <suzuki@in.ibm.com>
+ */
+
+#include <linux/objtool.h>
+#include <asm/reg.h>
+#include <asm/page.h>
+#include <asm/mmu.h>
+#include <asm/ppc_asm.h>
+#include <asm/kexec.h>
+
+	.text
+
+	/*
+	 * Must be relocatable PIC code callable as a C function.
+	 */
+	.globl relocate_new_kernel
+relocate_new_kernel:
+	/* r3 = page_list   */
+	/* r4 = reboot_code_buffer */
+	/* r5 = start_address      */
+
+#ifdef CONFIG_PPC_85xx
+
+	mr	r29, r3
+	mr	r30, r4
+	mr	r31, r5
+
+#define ENTRY_MAPPING_KEXEC_SETUP
+#include <kernel/85xx_entry_mapping.S>
+#undef ENTRY_MAPPING_KEXEC_SETUP
+
+	mr      r3, r29
+	mr      r4, r30
+	mr      r5, r31
+
+	li	r0, 0
+#elif defined(CONFIG_44x)
+
+	/* Save our parameters */
+	mr	r29, r3
+	mr	r30, r4
+	mr	r31, r5
+
+#ifdef CONFIG_PPC_47x
+	/* Check for 47x cores */
+	mfspr	r3,SPRN_PVR
+	srwi	r3,r3,16
+	cmplwi	cr0,r3,PVR_476FPE@h
+	beq	setup_map_47x
+	cmplwi	cr0,r3,PVR_476@h
+	beq	setup_map_47x
+	cmplwi	cr0,r3,PVR_476_ISS@h
+	beq	setup_map_47x
+#endif /* CONFIG_PPC_47x */
+
+/*
+ * Code for setting up 1:1 mapping for PPC440x for KEXEC
+ *
+ * We cannot switch off the MMU on PPC44x.
+ * So we:
+ * 1) Invalidate all the mappings except the one we are running from.
+ * 2) Create a tmp mapping for our code in the other address space(TS) and
+ *    jump to it. Invalidate the entry we started in.
+ * 3) Create a 1:1 mapping for 0-2GiB in chunks of 256M in original TS.
+ * 4) Jump to the 1:1 mapping in original TS.
+ * 5) Invalidate the tmp mapping.
+ *
+ * - Based on the kexec support code for FSL BookE
+ *
+ */
+
+	/*
+	 * Load the PID with kernel PID (0).
+	 * Also load our MSR_IS and TID to MMUCR for TLB search.
+	 */
+	li	r3, 0
+	mtspr	SPRN_PID, r3
+	mfmsr	r4
+	andi.	r4,r4,MSR_IS@l
+	beq	wmmucr
+	oris	r3,r3,PPC44x_MMUCR_STS@h
+wmmucr:
+	mtspr	SPRN_MMUCR,r3
+	sync
+
+	/*
+	 * Invalidate all the TLB entries except the current entry
+	 * where we are running from
+	 */
+	bcl	20,31,$+4			/* Find our address */
+0:	mflr	r5				/* Make it accessible */
+	tlbsx	r23,0,r5			/* Find entry we are in */
+	li	r4,0				/* Start at TLB entry 0 */
+	li	r3,0				/* Set PAGEID inval value */
+1:	cmpw	r23,r4				/* Is this our entry? */
+	beq	skip				/* If so, skip the inval */
+	tlbwe	r3,r4,PPC44x_TLB_PAGEID		/* If not, inval the entry */
+skip:
+	addi	r4,r4,1				/* Increment */
+	cmpwi	r4,64				/* Are we done?	*/
+	bne	1b				/* If not, repeat */
+	isync
+
+	/* Create a temp mapping and jump to it */
+	andi.	r6, r23, 1		/* Find the index to use */
+	addi	r24, r6, 1		/* r24 will contain 1 or 2 */
+
+	mfmsr	r9			/* get the MSR */
+	rlwinm	r5, r9, 27, 31, 31	/* Extract the MSR[IS] */
+	xori	r7, r5, 1		/* Use the other address space */
+
+	/* Read the current mapping entries */
+	tlbre	r3, r23, PPC44x_TLB_PAGEID
+	tlbre	r4, r23, PPC44x_TLB_XLAT
+	tlbre	r5, r23, PPC44x_TLB_ATTRIB
+
+	/* Save our current XLAT entry */
+	mr	r25, r4
+
+	/* Extract the TLB PageSize */
+	li	r10, 1 			/* r10 will hold PageSize */
+	rlwinm	r11, r3, 0, 24, 27	/* bits 24-27 */
+
+	/* XXX: As of now we use 256M, 4K pages */
+	cmpwi	r11, PPC44x_TLB_256M
+	bne	tlb_4k
+	rotlwi	r10, r10, 28		/* r10 = 256M */
+	b	write_out
+tlb_4k:
+	cmpwi	r11, PPC44x_TLB_4K
+	bne	default
+	rotlwi	r10, r10, 12		/* r10 = 4K */
+	b	write_out
+default:
+	rotlwi	r10, r10, 10		/* r10 = 1K */
+
+write_out:
+	/*
+	 * Write out the tmp 1:1 mapping for this code in other address space
+	 * Fixup  EPN = RPN , TS=other address space
+	 */
+	insrwi	r3, r7, 1, 23		/* Bit 23 is TS for PAGEID field */
+
+	/* Write out the tmp mapping entries */
+	tlbwe	r3, r24, PPC44x_TLB_PAGEID
+	tlbwe	r4, r24, PPC44x_TLB_XLAT
+	tlbwe	r5, r24, PPC44x_TLB_ATTRIB
+
+	subi	r11, r10, 1		/* PageOffset Mask = PageSize - 1 */
+	not	r10, r11		/* Mask for PageNum */
+
+	/* Switch to other address space in MSR */
+	insrwi	r9, r7, 1, 26		/* Set MSR[IS] = r7 */
+
+	bcl	20,31,$+4
+1:	mflr	r8
+	addi	r8, r8, (2f-1b)		/* Find the target offset */
+
+	/* Jump to the tmp mapping */
+	mtspr	SPRN_SRR0, r8
+	mtspr	SPRN_SRR1, r9
+	rfi
+
+2:
+	/* Invalidate the entry we were executing from */
+	li	r3, 0
+	tlbwe	r3, r23, PPC44x_TLB_PAGEID
+
+	/* attribute fields. rwx for SUPERVISOR mode */
+	li	r5, 0
+	ori	r5, r5, (PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_SX | PPC44x_TLB_G)
+
+	/* Create 1:1 mapping in 256M pages */
+	xori	r7, r7, 1			/* Revert back to Original TS */
+
+	li	r8, 0				/* PageNumber */
+	li	r6, 3				/* TLB Index, start at 3  */
+
+next_tlb:
+	rotlwi	r3, r8, 28			/* Create EPN (bits 0-3) */
+	mr	r4, r3				/* RPN = EPN  */
+	ori	r3, r3, (PPC44x_TLB_VALID | PPC44x_TLB_256M) /* SIZE = 256M, Valid */
+	insrwi	r3, r7, 1, 23			/* Set TS from r7 */
+
+	tlbwe	r3, r6, PPC44x_TLB_PAGEID	/* PageID field : EPN, V, SIZE */
+	tlbwe	r4, r6, PPC44x_TLB_XLAT		/* Address translation : RPN   */
+	tlbwe	r5, r6, PPC44x_TLB_ATTRIB	/* Attributes */
+
+	addi	r8, r8, 1			/* Increment PN */
+	addi	r6, r6, 1			/* Increment TLB Index */
+	cmpwi	r8, 8				/* Are we done ? */
+	bne	next_tlb
+	isync
+
+	/* Jump to the new mapping 1:1 */
+	li	r9,0
+	insrwi	r9, r7, 1, 26			/* Set MSR[IS] = r7 */
+
+	bcl	20,31,$+4
+1:	mflr	r8
+	and	r8, r8, r11			/* Get our offset within page */
+	addi	r8, r8, (2f-1b)
+
+	and	r5, r25, r10			/* Get our target PageNum */
+	or	r8, r8, r5			/* Target jump address */
+
+	mtspr	SPRN_SRR0, r8
+	mtspr	SPRN_SRR1, r9
+	rfi
+2:
+	/* Invalidate the tmp entry we used */
+	li	r3, 0
+	tlbwe	r3, r24, PPC44x_TLB_PAGEID
+	sync
+	b	ppc44x_map_done
+
+#ifdef CONFIG_PPC_47x
+
+	/* 1:1 mapping for 47x */
+
+setup_map_47x:
+
+	/*
+	 * Load the kernel pid (0) to PID and also to MMUCR[TID].
+	 * Also set the MSR IS->MMUCR STS
+	 */
+	li	r3, 0
+	mtspr	SPRN_PID, r3			/* Set PID */
+	mfmsr	r4				/* Get MSR */
+	andi.	r4, r4, MSR_IS@l		/* TS=1? */
+	beq	1f				/* If not, leave STS=0 */
+	oris	r3, r3, PPC47x_MMUCR_STS@h	/* Set STS=1 */
+1:	mtspr	SPRN_MMUCR, r3			/* Put MMUCR */
+	sync
+
+	/* Find the entry we are running from */
+	bcl	20,31,$+4
+2:	mflr	r23
+	tlbsx	r23, 0, r23
+	tlbre	r24, r23, 0			/* TLB Word 0 */
+	tlbre	r25, r23, 1			/* TLB Word 1 */
+	tlbre	r26, r23, 2			/* TLB Word 2 */
+
+
+	/*
+	 * Invalidates all the tlb entries by writing to 256 RPNs(r4)
+	 * of 4k page size in all  4 ways (0-3 in r3).
+	 * This would invalidate the entire UTLB including the one we are
+	 * running from. However the shadow TLB entries would help us
+	 * to continue the execution, until we flush them (rfi/isync).
+	 */
+	addis	r3, 0, 0x8000			/* specify the way */
+	addi	r4, 0, 0			/* TLB Word0 = (EPN=0, VALID = 0) */
+	addi	r5, 0, 0
+	b	clear_utlb_entry
+
+	/* Align the loop to speed things up. from head_44x.S */
+	.align	6
+
+clear_utlb_entry:
+
+	tlbwe	r4, r3, 0
+	tlbwe	r5, r3, 1
+	tlbwe	r5, r3, 2
+	addis	r3, r3, 0x2000			/* Increment the way */
+	cmpwi	r3, 0
+	bne	clear_utlb_entry
+	addis	r3, 0, 0x8000
+	addis	r4, r4, 0x100			/* Increment the EPN */
+	cmpwi	r4, 0
+	bne	clear_utlb_entry
+
+	/* Create the entries in the other address space */
+	mfmsr	r5
+	rlwinm	r7, r5, 27, 31, 31		/* Get the TS (Bit 26) from MSR */
+	xori	r7, r7, 1			/* r7 = !TS */
+
+	insrwi	r24, r7, 1, 21			/* Change the TS in the saved TLB word 0 */
+
+	/*
+	 * write out the TLB entries for the tmp mapping
+	 * Use way '0' so that we could easily invalidate it later.
+	 */
+	lis	r3, 0x8000			/* Way '0' */
+
+	tlbwe	r24, r3, 0
+	tlbwe	r25, r3, 1
+	tlbwe	r26, r3, 2
+
+	/* Update the msr to the new TS */
+	insrwi	r5, r7, 1, 26
+
+	bcl	20,31,$+4
+1:	mflr	r6
+	addi	r6, r6, (2f-1b)
+
+	mtspr	SPRN_SRR0, r6
+	mtspr	SPRN_SRR1, r5
+	rfi
+
+	/*
+	 * Now we are in the tmp address space.
+	 * Create a 1:1 mapping for 0-2GiB in the original TS.
+	 */
+2:
+	li	r3, 0
+	li	r4, 0				/* TLB Word 0 */
+	li	r5, 0				/* TLB Word 1 */
+	li	r6, 0
+	ori	r6, r6, PPC47x_TLB2_S_RWX	/* TLB word 2 */
+
+	li	r8, 0				/* PageIndex */
+
+	xori	r7, r7, 1			/* revert back to original TS */
+
+write_utlb:
+	rotlwi	r5, r8, 28			/* RPN = PageIndex * 256M */
+						/* ERPN = 0 as we don't use memory above 2G */
+
+	mr	r4, r5				/* EPN = RPN */
+	ori	r4, r4, (PPC47x_TLB0_VALID | PPC47x_TLB0_256M)
+	insrwi	r4, r7, 1, 21			/* Insert the TS to Word 0 */
+
+	tlbwe	r4, r3, 0			/* Write out the entries */
+	tlbwe	r5, r3, 1
+	tlbwe	r6, r3, 2
+	addi	r8, r8, 1
+	cmpwi	r8, 8				/* Have we completed ? */
+	bne	write_utlb
+
+	/* make sure we complete the TLB write up */
+	isync
+
+	/*
+	 * Prepare to jump to the 1:1 mapping.
+	 * 1) Extract page size of the tmp mapping
+	 *    DSIZ = TLB_Word0[22:27]
+	 * 2) Calculate the physical address of the address
+	 *    to jump to.
+	 */
+	rlwinm	r10, r24, 0, 22, 27
+
+	cmpwi	r10, PPC47x_TLB0_4K
+	li	r10, 0x1000			/* r10 = 4k */
+	beq	0f
+
+	/* Defaults to 256M */
+	lis	r10, 0x1000
+
+0:	bcl	20,31,$+4
+1:	mflr	r4
+	addi	r4, r4, (2f-1b)			/* virtual address  of 2f */
+
+	subi	r11, r10, 1			/* offsetmask = Pagesize - 1 */
+	not	r10, r11			/* Pagemask = ~(offsetmask) */
+
+	and	r5, r25, r10			/* Physical page */
+	and	r6, r4, r11			/* offset within the current page */
+
+	or	r5, r5, r6			/* Physical address for 2f */
+
+	/* Switch the TS in MSR to the original one */
+	mfmsr	r8
+	insrwi	r8, r7, 1, 26
+
+	mtspr	SPRN_SRR1, r8
+	mtspr	SPRN_SRR0, r5
+	rfi
+
+2:
+	/* Invalidate the tmp mapping */
+	lis	r3, 0x8000			/* Way '0' */
+
+	clrrwi	r24, r24, 12			/* Clear the valid bit */
+	tlbwe	r24, r3, 0
+	tlbwe	r25, r3, 1
+	tlbwe	r26, r3, 2
+
+	/* Make sure we complete the TLB write and flush the shadow TLB */
+	isync
+
+#endif
+
+ppc44x_map_done:
+
+
+	/* Restore the parameters */
+	mr	r3, r29
+	mr	r4, r30
+	mr	r5, r31
+
+	li	r0, 0
+#else
+	li	r0, 0
+
+	/*
+	 * Set Machine Status Register to a known status,
+	 * switch the MMU off and jump to 1: in a single step.
+	 */
+
+	mr	r8, r0
+	ori     r8, r8, MSR_RI|MSR_ME
+	mtspr	SPRN_SRR1, r8
+	addi	r8, r4, 1f - relocate_new_kernel
+	mtspr	SPRN_SRR0, r8
+	sync
+	rfi
+
+1:
+#endif
+	/* from this point address translation is turned off */
+	/* and interrupts are disabled */
+
+	/* set a new stack at the bottom of our page... */
+	/* (not really needed now) */
+	addi	r1, r4, KEXEC_CONTROL_PAGE_SIZE - 8 /* for LR Save+Back Chain */
+	stw	r0, 0(r1)
+
+	/* Do the copies */
+	li	r6, 0 /* checksum */
+	mr	r0, r3
+	b	1f
+
+0:	/* top, read another word for the indirection page */
+	lwzu	r0, 4(r3)
+
+1:
+	/* is it a destination page? (r8) */
+	rlwinm.	r7, r0, 0, 31, 31 /* IND_DESTINATION (1<<0) */
+	beq	2f
+
+	rlwinm	r8, r0, 0, 0, 19 /* clear kexec flags, page align */
+	b	0b
+
+2:	/* is it an indirection page? (r3) */
+	rlwinm.	r7, r0, 0, 30, 30 /* IND_INDIRECTION (1<<1) */
+	beq	2f
+
+	rlwinm	r3, r0, 0, 0, 19 /* clear kexec flags, page align */
+	subi	r3, r3, 4
+	b	0b
+
+2:	/* are we done? */
+	rlwinm.	r7, r0, 0, 29, 29 /* IND_DONE (1<<2) */
+	beq	2f
+	b	3f
+
+2:	/* is it a source page? (r9) */
+	rlwinm.	r7, r0, 0, 28, 28 /* IND_SOURCE (1<<3) */
+	beq	0b
+
+	rlwinm	r9, r0, 0, 0, 19 /* clear kexec flags, page align */
+
+	li	r7, PAGE_SIZE / 4
+	mtctr   r7
+	subi    r9, r9, 4
+	subi    r8, r8, 4
+9:
+	lwzu    r0, 4(r9)  /* do the copy */
+	xor	r6, r6, r0
+	stwu    r0, 4(r8)
+	dcbst	0, r8
+	sync
+	icbi	0, r8
+	bdnz    9b
+
+	addi    r9, r9, 4
+	addi    r8, r8, 4
+	b	0b
+
+3:
+
+	/* To be certain of avoiding problems with self-modifying code
+	 * execute a serializing instruction here.
+	 */
+	isync
+	sync
+
+	mfspr	r3, SPRN_PIR /* current core we are running on */
+	mr	r4, r5 /* load physical address of chunk called */
+
+	/* jump to the entry point, usually the setup routine */
+	mtlr	r5
+	blrl
+
+1:	b	1b
+
+relocate_new_kernel_end:
+
+	.globl relocate_new_kernel_size
+relocate_new_kernel_size:
+	.long relocate_new_kernel_end - relocate_new_kernel

linux-7.2.3/arch/powerpc/kexec/vmcore_info.c

@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/vmcore_info.h>
+#include <asm/pgalloc.h>
+
+void arch_crash_save_vmcoreinfo(void)
+{
+
+#ifdef CONFIG_NUMA
+	VMCOREINFO_SYMBOL(node_data);
+	VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
+#endif
+#ifndef CONFIG_NUMA
+	VMCOREINFO_SYMBOL(contig_page_data);
+#endif
+#if defined(CONFIG_PPC64) && defined(CONFIG_SPARSEMEM_VMEMMAP)
+	VMCOREINFO_SYMBOL(vmemmap_list);
+	VMCOREINFO_SYMBOL(mmu_vmemmap_psize);
+	VMCOREINFO_SYMBOL(mmu_psize_defs);
+	VMCOREINFO_STRUCT_SIZE(vmemmap_backing);
+	VMCOREINFO_OFFSET(vmemmap_backing, list);
+	VMCOREINFO_OFFSET(vmemmap_backing, phys);
+	VMCOREINFO_OFFSET(vmemmap_backing, virt_addr);
+	VMCOREINFO_STRUCT_SIZE(mmu_psize_def);
+	VMCOREINFO_OFFSET(mmu_psize_def, shift);
+#endif
+	VMCOREINFO_SYMBOL(cur_cpu_spec);
+	VMCOREINFO_OFFSET(cpu_spec, cpu_features);
+	VMCOREINFO_OFFSET(cpu_spec, mmu_features);
+	vmcoreinfo_append_str("NUMBER(RADIX_MMU)=%d\n", early_radix_enabled());
+	vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
+}