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linux-7.2.3/arch/parisc/mm/Makefile

@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for arch/parisc/mm
+#
+
+obj-y	 := init.o fault.o ioremap.o fixmap.o
+obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o

linux-7.2.3/arch/parisc/mm/fault.c

@@ -0,0 +1,535 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ *
+ * Copyright (C) 1995, 1996, 1997, 1998 by Ralf Baechle
+ * Copyright 1999 SuSE GmbH (Philipp Rumpf, prumpf@tux.org)
+ * Copyright 1999 Hewlett Packard Co.
+ *
+ */
+
+#include <linux/mm.h>
+#include <linux/ptrace.h>
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <linux/interrupt.h>
+#include <linux/extable.h>
+#include <linux/uaccess.h>
+#include <linux/hugetlb.h>
+#include <linux/perf_event.h>
+
+#include <asm/traps.h>
+
+#define DEBUG_NATLB 0
+
+/* Various important other fields */
+#define bit22set(x)		(x & 0x00000200)
+#define bits23_25set(x)		(x & 0x000001c0)
+#define isGraphicsFlushRead(x)	((x & 0xfc003fdf) == 0x04001a80)
+				/* extended opcode is 0x6a */
+
+#define BITSSET		0x1c0	/* for identifying LDCW */
+
+
+int show_unhandled_signals = 1;
+
+/*
+ * parisc_acctyp(unsigned int inst) --
+ *    Given a PA-RISC memory access instruction, determine if the
+ *    instruction would perform a memory read or memory write
+ *    operation.
+ *
+ *    This function assumes that the given instruction is a memory access
+ *    instruction (i.e. you should really only call it if you know that
+ *    the instruction has generated some sort of a memory access fault).
+ *
+ * Returns:
+ *   VM_READ  if read operation
+ *   VM_WRITE if write operation
+ *   VM_EXEC  if execute operation
+ */
+unsigned long
+parisc_acctyp(unsigned long code, unsigned int inst)
+{
+	if (code == 6 || code == 16)
+	    return VM_EXEC;
+
+	switch (inst & 0xf0000000) {
+	case 0x40000000: /* load */
+	case 0x50000000: /* new load */
+		return VM_READ;
+
+	case 0x60000000: /* store */
+	case 0x70000000: /* new store */
+		return VM_WRITE;
+
+	case 0x20000000: /* coproc */
+	case 0x30000000: /* coproc2 */
+		if (bit22set(inst))
+			return VM_WRITE;
+		fallthrough;
+
+	case 0x0: /* indexed/memory management */
+		if (bit22set(inst)) {
+			/*
+			 * Check for the 'Graphics Flush Read' instruction.
+			 * It resembles an FDC instruction, except for bits
+			 * 20 and 21. Any combination other than zero will
+			 * utilize the block mover functionality on some
+			 * older PA-RISC platforms.  The case where a block
+			 * move is performed from VM to graphics IO space
+			 * should be treated as a READ.
+			 *
+			 * The significance of bits 20,21 in the FDC
+			 * instruction is:
+			 *
+			 *   00  Flush data cache (normal instruction behavior)
+			 *   01  Graphics flush write  (IO space -> VM)
+			 *   10  Graphics flush read   (VM -> IO space)
+			 *   11  Graphics flush read/write (VM <-> IO space)
+			 */
+			if (isGraphicsFlushRead(inst))
+				return VM_READ;
+			return VM_WRITE;
+		} else {
+			/*
+			 * Check for LDCWX and LDCWS (semaphore instructions).
+			 * If bits 23 through 25 are all 1's it is one of
+			 * the above two instructions and is a write.
+			 *
+			 * Note: With the limited bits we are looking at,
+			 * this will also catch PROBEW and PROBEWI. However,
+			 * these should never get in here because they don't
+			 * generate exceptions of the type:
+			 *   Data TLB miss fault/data page fault
+			 *   Data memory protection trap
+			 */
+			if (bits23_25set(inst) == BITSSET)
+				return VM_WRITE;
+		}
+		return VM_READ; /* Default */
+	}
+	return VM_READ; /* Default */
+}
+
+#undef bit22set
+#undef bits23_25set
+#undef isGraphicsFlushRead
+#undef BITSSET
+
+
+#if 0
+/* This is the treewalk to find a vma which is the highest that has
+ * a start < addr.  We're using find_vma_prev instead right now, but
+ * we might want to use this at some point in the future.  Probably
+ * not, but I want it committed to CVS so I don't lose it :-)
+ */
+			while (tree != vm_avl_empty) {
+				if (tree->vm_start > addr) {
+					tree = tree->vm_avl_left;
+				} else {
+					prev = tree;
+					if (prev->vm_next == NULL)
+						break;
+					if (prev->vm_next->vm_start > addr)
+						break;
+					tree = tree->vm_avl_right;
+				}
+			}
+#endif
+
+int fixup_exception(struct pt_regs *regs)
+{
+	const struct exception_table_entry *fix;
+
+	fix = search_exception_tables(regs->iaoq[0]);
+	if (fix) {
+		/*
+		 * Fix up get_user() and put_user().
+		 * ASM_EXCEPTIONTABLE_ENTRY_EFAULT() sets the least-significant
+		 * bit in the relative address of the fixup routine to indicate
+		 * that the register encoded in the "or %r0,%r0,register"
+		 * opcode should be loaded with -EFAULT to report a userspace
+		 * access error.
+		 */
+		if (fix->fixup & 1) {
+			int fault_error_reg = fix->err_opcode & 0x1f;
+			if (!WARN_ON(!fault_error_reg))
+				regs->gr[fault_error_reg] = -EFAULT;
+			pr_debug("Unalignment fixup of register %d at %pS\n",
+				fault_error_reg, (void*)regs->iaoq[0]);
+
+			/* zero target register for get_user() */
+			if (parisc_acctyp(0, regs->iir) == VM_READ) {
+				int treg = regs->iir & 0x1f;
+				BUG_ON(treg == 0);
+				regs->gr[treg] = 0;
+			}
+		}
+
+		regs->iaoq[0] = (unsigned long)&fix->fixup + fix->fixup;
+		regs->iaoq[0] &= ~3;
+		/*
+		 * NOTE: In some cases the faulting instruction
+		 * may be in the delay slot of a branch. We
+		 * don't want to take the branch, so we don't
+		 * increment iaoq[1], instead we set it to be
+		 * iaoq[0]+4, and clear the B bit in the PSW
+		 */
+		regs->iaoq[1] = regs->iaoq[0] + 4;
+		regs->gr[0] &= ~PSW_B; /* IPSW in gr[0] */
+
+		return 1;
+	}
+
+	return 0;
+}
+
+/*
+ * parisc hardware trap list
+ *
+ * Documented in section 3 "Addressing and Access Control" of the
+ * "PA-RISC 1.1 Architecture and Instruction Set Reference Manual"
+ * https://parisc.wiki.kernel.org/index.php/File:Pa11_acd.pdf
+ *
+ * For implementation see handle_interruption() in traps.c
+ */
+static const char * const trap_description[] = {
+	[1] =	"High-priority machine check (HPMC)",
+	[2] =	"Power failure interrupt",
+	[3] =	"Recovery counter trap",
+	[5] =	"Low-priority machine check",
+	[6] =	"Instruction TLB miss fault",
+	[7] =	"Instruction access rights / protection trap",
+	[8] =	"Illegal instruction trap",
+	[9] =	"Break instruction trap",
+	[10] =	"Privileged operation trap",
+	[11] =	"Privileged register trap",
+	[12] =	"Overflow trap",
+	[13] =	"Conditional trap",
+	[14] =	"FP Assist Exception trap",
+	[15] =	"Data TLB miss fault",
+	[16] =	"Non-access ITLB miss fault",
+	[17] =	"Non-access DTLB miss fault",
+	[18] =	"Data memory protection/unaligned access trap",
+	[19] =	"Data memory break trap",
+	[20] =	"TLB dirty bit trap",
+	[21] =	"Page reference trap",
+	[22] =	"Assist emulation trap",
+	[25] =	"Taken branch trap",
+	[26] =	"Data memory access rights trap",
+	[27] =	"Data memory protection ID trap",
+	[28] =	"Unaligned data reference trap",
+};
+
+const char *trap_name(unsigned long code)
+{
+	const char *t = NULL;
+
+	if (code < ARRAY_SIZE(trap_description))
+		t = trap_description[code];
+
+	return t ? t : "Unknown trap";
+}
+
+/*
+ * Print out info about fatal segfaults, if the show_unhandled_signals
+ * sysctl is set:
+ */
+static inline void
+show_signal_msg(struct pt_regs *regs, unsigned long code,
+		unsigned long address, struct task_struct *tsk,
+		struct vm_area_struct *vma)
+{
+	if (!unhandled_signal(tsk, SIGSEGV))
+		return;
+
+	if (!printk_ratelimit())
+		return;
+
+	pr_warn("\n");
+	pr_warn("do_page_fault() command='%s' type=%lu address=0x%08lx",
+	    tsk->comm, code, address);
+	print_vma_addr(KERN_CONT " in ", regs->iaoq[0]);
+
+	pr_cont("\ntrap #%lu: %s%c", code, trap_name(code),
+		vma ? ',':'\n');
+
+	if (vma)
+		pr_cont(" vm_start = 0x%08lx, vm_end = 0x%08lx\n",
+			vma->vm_start, vma->vm_end);
+
+	show_regs(regs);
+}
+
+void do_page_fault(struct pt_regs *regs, unsigned long code,
+			      unsigned long address)
+{
+	struct vm_area_struct *vma, *prev_vma;
+	struct task_struct *tsk;
+	struct mm_struct *mm;
+	unsigned long acc_type;
+	vm_fault_t fault = 0;
+	unsigned int flags;
+	char *msg;
+
+	tsk = current;
+	mm = tsk->mm;
+	if (!mm) {
+		msg = "Page fault: no context";
+		goto no_context;
+	}
+
+	flags = FAULT_FLAG_DEFAULT;
+	if (user_mode(regs))
+		flags |= FAULT_FLAG_USER;
+
+	acc_type = parisc_acctyp(code, regs->iir);
+	if (acc_type & VM_WRITE)
+		flags |= FAULT_FLAG_WRITE;
+	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
+retry:
+	mmap_read_lock(mm);
+	vma = find_vma_prev(mm, address, &prev_vma);
+	if (!vma || address < vma->vm_start) {
+		if (!prev_vma || !(prev_vma->vm_flags & VM_GROWSUP))
+			goto bad_area;
+		vma = expand_stack(mm, address);
+		if (!vma)
+			goto bad_area_nosemaphore;
+	}
+
+/*
+ * Ok, we have a good vm_area for this memory access. We still need to
+ * check the access permissions.
+ */
+
+	if ((vma->vm_flags & acc_type) != acc_type)
+		goto bad_area;
+
+	/*
+	 * If for any reason at all we couldn't handle the fault, make
+	 * sure we exit gracefully rather than endlessly redo the
+	 * fault.
+	 */
+
+	fault = handle_mm_fault(vma, address, flags, regs);
+
+	if (fault_signal_pending(fault, regs)) {
+		if (!user_mode(regs)) {
+			msg = "Page fault: fault signal on kernel memory";
+			goto no_context;
+		}
+		return;
+	}
+
+	/* The fault is fully completed (including releasing mmap lock) */
+	if (fault & VM_FAULT_COMPLETED)
+		return;
+
+	if (unlikely(fault & VM_FAULT_ERROR)) {
+		/*
+		 * We hit a shared mapping outside of the file, or some
+		 * other thing happened to us that made us unable to
+		 * handle the page fault gracefully.
+		 */
+		if (fault & VM_FAULT_OOM)
+			goto out_of_memory;
+		else if (fault & VM_FAULT_SIGSEGV)
+			goto bad_area;
+		else if (fault & (VM_FAULT_SIGBUS|VM_FAULT_HWPOISON|
+				  VM_FAULT_HWPOISON_LARGE))
+			goto bad_area;
+		BUG();
+	}
+	if (fault & VM_FAULT_RETRY) {
+		/*
+		 * No need to mmap_read_unlock(mm) as we would
+		 * have already released it in __lock_page_or_retry
+		 * in mm/filemap.c.
+		 */
+		flags |= FAULT_FLAG_TRIED;
+		goto retry;
+	}
+	mmap_read_unlock(mm);
+	return;
+
+/*
+ * Something tried to access memory that isn't in our memory map..
+ */
+bad_area:
+	mmap_read_unlock(mm);
+
+bad_area_nosemaphore:
+	if (!user_mode(regs) && fixup_exception(regs)) {
+		return;
+	}
+
+	if (user_mode(regs)) {
+		int signo, si_code;
+
+		switch (code) {
+		case 15:	/* Data TLB miss fault/Data page fault */
+			/* send SIGSEGV when outside of vma */
+			if (!vma ||
+			    address < vma->vm_start || address >= vma->vm_end) {
+				signo = SIGSEGV;
+				si_code = SEGV_MAPERR;
+				break;
+			}
+
+			/* send SIGSEGV for wrong permissions */
+			if ((vma->vm_flags & acc_type) != acc_type) {
+				signo = SIGSEGV;
+				si_code = SEGV_ACCERR;
+				break;
+			}
+
+			/* probably address is outside of mapped file */
+			fallthrough;
+		case 17:	/* NA data TLB miss / page fault */
+		case 18:	/* Unaligned access - PCXS only */
+			signo = SIGBUS;
+			si_code = (code == 18) ? BUS_ADRALN : BUS_ADRERR;
+			break;
+		case 16:	/* Non-access instruction TLB miss fault */
+		case 26:	/* PCXL: Data memory access rights trap */
+		default:
+			signo = SIGSEGV;
+			si_code = (code == 26) ? SEGV_ACCERR : SEGV_MAPERR;
+			break;
+		}
+#ifdef CONFIG_MEMORY_FAILURE
+		if (fault & (VM_FAULT_HWPOISON|VM_FAULT_HWPOISON_LARGE)) {
+			unsigned int lsb = 0;
+			printk(KERN_ERR
+	"MCE: Killing %s:%d due to hardware memory corruption fault at %08lx\n",
+			tsk->comm, tsk->pid, address);
+			/*
+			 * Either small page or large page may be poisoned.
+			 * In other words, VM_FAULT_HWPOISON_LARGE and
+			 * VM_FAULT_HWPOISON are mutually exclusive.
+			 */
+			if (fault & VM_FAULT_HWPOISON_LARGE)
+				lsb = hstate_index_to_shift(VM_FAULT_GET_HINDEX(fault));
+			else if (fault & VM_FAULT_HWPOISON)
+				lsb = PAGE_SHIFT;
+
+			force_sig_mceerr(BUS_MCEERR_AR, (void __user *) address,
+					 lsb);
+			return;
+		}
+#endif
+		show_signal_msg(regs, code, address, tsk, vma);
+
+		force_sig_fault(signo, si_code, (void __user *) address);
+		return;
+	}
+	msg = "Page fault: bad address";
+
+no_context:
+
+	if (!user_mode(regs) && fixup_exception(regs)) {
+		return;
+	}
+
+	parisc_terminate(msg, regs, code, address);
+
+out_of_memory:
+	mmap_read_unlock(mm);
+	if (!user_mode(regs)) {
+		msg = "Page fault: out of memory";
+		goto no_context;
+	}
+	pagefault_out_of_memory();
+}
+
+/* Handle non-access data TLB miss faults.
+ *
+ * For probe instructions, accesses to userspace are considered allowed
+ * if they lie in a valid VMA and the access type matches. We are not
+ * allowed to handle MM faults here so there may be situations where an
+ * actual access would fail even though a probe was successful.
+ */
+int
+handle_nadtlb_fault(struct pt_regs *regs)
+{
+	unsigned long insn = regs->iir;
+	int breg, treg, xreg, val = 0;
+	struct vm_area_struct *vma;
+	struct task_struct *tsk;
+	struct mm_struct *mm;
+	unsigned long address;
+	unsigned long acc_type;
+
+	switch (insn & 0x380) {
+	case 0x280:
+		/* FDC instruction */
+		fallthrough;
+	case 0x380:
+		/* PDC and FIC instructions */
+		if (DEBUG_NATLB && printk_ratelimit()) {
+			pr_warn("WARNING: nullifying cache flush/purge instruction\n");
+			show_regs(regs);
+		}
+		if (insn & 0x20) {
+			/* Base modification */
+			breg = (insn >> 21) & 0x1f;
+			xreg = (insn >> 16) & 0x1f;
+			if (breg && xreg)
+				regs->gr[breg] += regs->gr[xreg];
+		}
+		regs->gr[0] |= PSW_N;
+		return 1;
+
+	case 0x180:
+		/* PROBE instruction */
+		treg = insn & 0x1f;
+		if (regs->isr) {
+			tsk = current;
+			mm = tsk->mm;
+			if (mm) {
+				/* Search for VMA */
+				address = regs->ior;
+				mmap_read_lock(mm);
+				vma = vma_lookup(mm, address);
+				mmap_read_unlock(mm);
+
+				/*
+				 * Check if access to the VMA is okay.
+				 * We don't allow for stack expansion.
+				 */
+				acc_type = (insn & 0x40) ? VM_WRITE : VM_READ;
+				if (vma
+				    && (vma->vm_flags & acc_type) == acc_type)
+					val = 1;
+			}
+		}
+		if (treg)
+			regs->gr[treg] = val;
+		regs->gr[0] |= PSW_N;
+		return 1;
+
+	case 0x300:
+		/* LPA instruction */
+		if (insn & 0x20) {
+			/* Base modification */
+			breg = (insn >> 21) & 0x1f;
+			xreg = (insn >> 16) & 0x1f;
+			if (breg && xreg)
+				regs->gr[breg] += regs->gr[xreg];
+		}
+		treg = insn & 0x1f;
+		if (treg)
+			regs->gr[treg] = 0;
+		regs->gr[0] |= PSW_N;
+		return 1;
+
+	default:
+		break;
+	}
+
+	return 0;
+}

linux-7.2.3/arch/parisc/mm/fixmap.c

@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * fixmaps for parisc
+ *
+ * Copyright (c) 2019 Sven Schnelle <svens@stackframe.org>
+ */
+
+#include <linux/kprobes.h>
+#include <linux/mm.h>
+#include <asm/cacheflush.h>
+#include <asm/fixmap.h>
+
+void notrace set_fixmap(enum fixed_addresses idx, phys_addr_t phys)
+{
+	unsigned long vaddr = __fix_to_virt(idx);
+	pgd_t *pgd = pgd_offset_k(vaddr);
+	p4d_t *p4d = p4d_offset(pgd, vaddr);
+	pud_t *pud = pud_offset(p4d, vaddr);
+	pmd_t *pmd = pmd_offset(pud, vaddr);
+	pte_t *pte;
+
+	pte = pte_offset_kernel(pmd, vaddr);
+	set_pte_at(&init_mm, vaddr, pte, __mk_pte(phys, PAGE_KERNEL_RWX));
+	flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
+}
+
+void notrace clear_fixmap(enum fixed_addresses idx)
+{
+	unsigned long vaddr = __fix_to_virt(idx);
+	pte_t *pte = virt_to_kpte(vaddr);
+
+	if (WARN_ON(pte_none(*pte)))
+		return;
+
+	pte_clear(&init_mm, vaddr, pte);
+
+	flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
+}

linux-7.2.3/arch/parisc/mm/hugetlbpage.c

@@ -0,0 +1,161 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PARISC64 Huge TLB page support.
+ *
+ * This parisc implementation is heavily based on the SPARC and x86 code.
+ *
+ * Copyright (C) 2015 Helge Deller <deller@gmx.de>
+ */
+
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/sched/mm.h>
+#include <linux/hugetlb.h>
+#include <linux/pagemap.h>
+#include <linux/sysctl.h>
+
+#include <asm/mman.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+#include <asm/cacheflush.h>
+#include <asm/mmu_context.h>
+
+
+
+
+pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
+			unsigned long addr, unsigned long sz)
+{
+	pgd_t *pgd;
+	p4d_t *p4d;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte = NULL;
+
+	/* We must align the address, because our caller will run
+	 * set_huge_pte_at() on whatever we return, which writes out
+	 * all of the sub-ptes for the hugepage range.  So we have
+	 * to give it the first such sub-pte.
+	 */
+	addr &= HPAGE_MASK;
+
+	pgd = pgd_offset(mm, addr);
+	p4d = p4d_offset(pgd, addr);
+	pud = pud_alloc(mm, p4d, addr);
+	if (pud) {
+		pmd = pmd_alloc(mm, pud, addr);
+		if (pmd)
+			pte = pte_alloc_huge(mm, pmd, addr);
+	}
+	return pte;
+}
+
+pte_t *huge_pte_offset(struct mm_struct *mm,
+		       unsigned long addr, unsigned long sz)
+{
+	pgd_t *pgd;
+	p4d_t *p4d;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte = NULL;
+
+	addr &= HPAGE_MASK;
+
+	pgd = pgd_offset(mm, addr);
+	if (!pgd_none(*pgd)) {
+		p4d = p4d_offset(pgd, addr);
+		if (!p4d_none(*p4d)) {
+			pud = pud_offset(p4d, addr);
+			if (!pud_none(*pud)) {
+				pmd = pmd_offset(pud, addr);
+				if (!pmd_none(*pmd))
+					pte = pte_offset_huge(pmd, addr);
+			}
+		}
+	}
+	return pte;
+}
+
+/* Purge data and instruction TLB entries.  Must be called holding
+ * the pa_tlb_lock.  The TLB purge instructions are slow on SMP
+ * machines since the purge must be broadcast to all CPUs.
+ */
+static inline void purge_tlb_entries_huge(struct mm_struct *mm, unsigned long addr)
+{
+	int i;
+
+	/* We may use multiple physical huge pages (e.g. 2x1 MB) to emulate
+	 * Linux standard huge pages (e.g. 2 MB) */
+	BUILD_BUG_ON(REAL_HPAGE_SHIFT > HPAGE_SHIFT);
+
+	addr &= HPAGE_MASK;
+	addr |= _HUGE_PAGE_SIZE_ENCODING_DEFAULT;
+
+	for (i = 0; i < (1 << (HPAGE_SHIFT-REAL_HPAGE_SHIFT)); i++) {
+		purge_tlb_entries(mm, addr);
+		addr += (1UL << REAL_HPAGE_SHIFT);
+	}
+}
+
+/* __set_huge_pte_at() must be called holding the pa_tlb_lock. */
+static void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
+		     pte_t *ptep, pte_t entry)
+{
+	unsigned long addr_start;
+	int i;
+
+	addr &= HPAGE_MASK;
+	addr_start = addr;
+
+	for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
+		set_pte(ptep, entry);
+		ptep++;
+
+		addr += PAGE_SIZE;
+		pte_val(entry) += PAGE_SIZE;
+	}
+
+	purge_tlb_entries_huge(mm, addr_start);
+}
+
+void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
+		     pte_t *ptep, pte_t entry, unsigned long sz)
+{
+	__set_huge_pte_at(mm, addr, ptep, entry);
+}
+
+
+pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
+			      pte_t *ptep, unsigned long sz)
+{
+	pte_t entry;
+
+	entry = *ptep;
+	__set_huge_pte_at(mm, addr, ptep, __pte(0));
+
+	return entry;
+}
+
+
+void huge_ptep_set_wrprotect(struct mm_struct *mm,
+				unsigned long addr, pte_t *ptep)
+{
+	pte_t old_pte;
+
+	old_pte = *ptep;
+	__set_huge_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
+}
+
+int huge_ptep_set_access_flags(struct vm_area_struct *vma,
+				unsigned long addr, pte_t *ptep,
+				pte_t pte, int dirty)
+{
+	int changed;
+	struct mm_struct *mm = vma->vm_mm;
+
+	changed = !pte_same(*ptep, pte);
+	if (changed) {
+		__set_huge_pte_at(mm, addr, ptep, pte);
+	}
+	return changed;
+}

linux-7.2.3/arch/parisc/mm/init.c

@@ -0,0 +1,994 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/arch/parisc/mm/init.c
+ *
+ *  Copyright (C) 1995	Linus Torvalds
+ *  Copyright 1999 SuSE GmbH
+ *    changed by Philipp Rumpf
+ *  Copyright 1999 Philipp Rumpf (prumpf@tux.org)
+ *  Copyright 2004 Randolph Chung (tausq@debian.org)
+ *  Copyright 2006-2007 Helge Deller (deller@gmx.de)
+ *
+ */
+
+
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/memblock.h>
+#include <linux/gfp.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/initrd.h>
+#include <linux/swap.h>
+#include <linux/unistd.h>
+#include <linux/nodemask.h>	/* for node_online_map */
+#include <linux/pagemap.h>	/* for release_pages */
+#include <linux/compat.h>
+#include <linux/execmem.h>
+
+#include <asm/pgalloc.h>
+#include <asm/tlb.h>
+#include <asm/pdc_chassis.h>
+#include <asm/mmzone.h>
+#include <asm/sections.h>
+#include <asm/msgbuf.h>
+#include <asm/sparsemem.h>
+#include <asm/asm-offsets.h>
+#include <asm/shmbuf.h>
+
+extern int  data_start;
+extern void parisc_kernel_start(void);	/* Kernel entry point in head.S */
+
+#if CONFIG_PGTABLE_LEVELS == 3
+pmd_t pmd0[PTRS_PER_PMD] __section(".data..vm0.pmd") __attribute__ ((aligned(PAGE_SIZE)));
+#endif
+
+pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".data..vm0.pgd") __attribute__ ((aligned(PAGE_SIZE)));
+pte_t pg0[PT_INITIAL * PTRS_PER_PTE] __section(".data..vm0.pte") __attribute__ ((aligned(PAGE_SIZE)));
+
+static struct resource data_resource = {
+	.name	= "Kernel data",
+	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
+};
+
+static struct resource code_resource = {
+	.name	= "Kernel code",
+	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
+};
+
+static struct resource pdcdata_resource = {
+	.name	= "PDC data (Page Zero)",
+	.start	= 0,
+	.end	= 0x9ff,
+	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM,
+};
+
+static struct resource sysram_resources[MAX_PHYSMEM_RANGES] __ro_after_init;
+
+/* The following array is initialized from the firmware specific
+ * information retrieved in kernel/inventory.c.
+ */
+
+physmem_range_t pmem_ranges[MAX_PHYSMEM_RANGES] __initdata;
+int npmem_ranges __initdata;
+
+#ifdef CONFIG_64BIT
+#define MAX_MEM         (1UL << MAX_PHYSMEM_BITS)
+#else /* !CONFIG_64BIT */
+#define MAX_MEM         (3584U*1024U*1024U)
+#endif /* !CONFIG_64BIT */
+
+static unsigned long mem_limit __read_mostly = MAX_MEM;
+
+static void __init mem_limit_func(void)
+{
+	char *cp, *end;
+	unsigned long limit;
+
+	/* We need this before __setup() functions are called */
+
+	limit = MAX_MEM;
+	for (cp = boot_command_line; *cp; ) {
+		if (memcmp(cp, "mem=", 4) == 0) {
+			cp += 4;
+			limit = memparse(cp, &end);
+			if (end != cp)
+				break;
+			cp = end;
+		} else {
+			while (*cp != ' ' && *cp)
+				++cp;
+			while (*cp == ' ')
+				++cp;
+		}
+	}
+
+	if (limit < mem_limit)
+		mem_limit = limit;
+}
+
+#define MAX_GAP (0x40000000UL >> PAGE_SHIFT)
+
+static void __init setup_bootmem(void)
+{
+	unsigned long mem_max;
+#ifndef CONFIG_SPARSEMEM
+	physmem_range_t pmem_holes[MAX_PHYSMEM_RANGES - 1];
+	int npmem_holes;
+#endif
+	int i, sysram_resource_count;
+
+	disable_sr_hashing(); /* Turn off space register hashing */
+
+	/*
+	 * Sort the ranges. Since the number of ranges is typically
+	 * small, and performance is not an issue here, just do
+	 * a simple insertion sort.
+	 */
+
+	for (i = 1; i < npmem_ranges; i++) {
+		int j;
+
+		for (j = i; j > 0; j--) {
+			if (pmem_ranges[j-1].start_pfn <
+			    pmem_ranges[j].start_pfn) {
+
+				break;
+			}
+			swap(pmem_ranges[j-1], pmem_ranges[j]);
+		}
+	}
+
+#ifndef CONFIG_SPARSEMEM
+	/*
+	 * Throw out ranges that are too far apart (controlled by
+	 * MAX_GAP).
+	 */
+
+	for (i = 1; i < npmem_ranges; i++) {
+		if (pmem_ranges[i].start_pfn -
+			(pmem_ranges[i-1].start_pfn +
+			 pmem_ranges[i-1].pages) > MAX_GAP) {
+			npmem_ranges = i;
+			printk("Large gap in memory detected (%ld pages). "
+			       "Consider turning on CONFIG_SPARSEMEM\n",
+			       pmem_ranges[i].start_pfn -
+			       (pmem_ranges[i-1].start_pfn +
+			        pmem_ranges[i-1].pages));
+			break;
+		}
+	}
+#endif
+
+	/* Print the memory ranges */
+	pr_info("Memory Ranges:\n");
+
+	for (i = 0; i < npmem_ranges; i++) {
+		struct resource *res = &sysram_resources[i];
+		unsigned long start;
+		unsigned long size;
+
+		size = (pmem_ranges[i].pages << PAGE_SHIFT);
+		start = (pmem_ranges[i].start_pfn << PAGE_SHIFT);
+		pr_info("%2d) Start 0x%016lx End 0x%016lx Size %6ld MB\n",
+			i, start, start + (size - 1), size >> 20);
+
+		/* request memory resource */
+		res->name = "System RAM";
+		res->start = start;
+		res->end = start + size - 1;
+		res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
+		request_resource(&iomem_resource, res);
+	}
+
+	sysram_resource_count = npmem_ranges;
+
+	/*
+	 * For 32 bit kernels we limit the amount of memory we can
+	 * support, in order to preserve enough kernel address space
+	 * for other purposes. For 64 bit kernels we don't normally
+	 * limit the memory, but this mechanism can be used to
+	 * artificially limit the amount of memory (and it is written
+	 * to work with multiple memory ranges).
+	 */
+
+	mem_limit_func();       /* check for "mem=" argument */
+
+	mem_max = 0;
+	for (i = 0; i < npmem_ranges; i++) {
+		unsigned long rsize;
+
+		rsize = pmem_ranges[i].pages << PAGE_SHIFT;
+		if ((mem_max + rsize) > mem_limit) {
+			printk(KERN_WARNING "Memory truncated to %ld MB\n", mem_limit >> 20);
+			if (mem_max == mem_limit)
+				npmem_ranges = i;
+			else {
+				pmem_ranges[i].pages =   (mem_limit >> PAGE_SHIFT)
+						       - (mem_max >> PAGE_SHIFT);
+				npmem_ranges = i + 1;
+				mem_max = mem_limit;
+			}
+			break;
+		}
+		mem_max += rsize;
+	}
+
+	printk(KERN_INFO "Total Memory: %ld MB\n",mem_max >> 20);
+
+#ifndef CONFIG_SPARSEMEM
+	/* Merge the ranges, keeping track of the holes */
+	{
+		unsigned long end_pfn;
+		unsigned long hole_pages;
+
+		npmem_holes = 0;
+		end_pfn = pmem_ranges[0].start_pfn + pmem_ranges[0].pages;
+		for (i = 1; i < npmem_ranges; i++) {
+
+			hole_pages = pmem_ranges[i].start_pfn - end_pfn;
+			if (hole_pages) {
+				pmem_holes[npmem_holes].start_pfn = end_pfn;
+				pmem_holes[npmem_holes++].pages = hole_pages;
+				end_pfn += hole_pages;
+			}
+			end_pfn += pmem_ranges[i].pages;
+		}
+
+		pmem_ranges[0].pages = end_pfn - pmem_ranges[0].start_pfn;
+		npmem_ranges = 1;
+	}
+#endif
+
+	/*
+	 * Initialize and free the full range of memory in each range.
+	 */
+
+	max_pfn = 0;
+	for (i = 0; i < npmem_ranges; i++) {
+		unsigned long start_pfn;
+		unsigned long npages;
+		unsigned long start;
+		unsigned long size;
+
+		start_pfn = pmem_ranges[i].start_pfn;
+		npages = pmem_ranges[i].pages;
+
+		start = start_pfn << PAGE_SHIFT;
+		size = npages << PAGE_SHIFT;
+
+		/* add system RAM memblock */
+		memblock_add(start, size);
+
+		if ((start_pfn + npages) > max_pfn)
+			max_pfn = start_pfn + npages;
+	}
+
+	/*
+	 * We can't use memblock top-down allocations because we only
+	 * created the initial mapping up to KERNEL_INITIAL_SIZE in
+	 * the assembly bootup code.
+	 */
+	memblock_set_bottom_up(true);
+
+	/* IOMMU is always used to access "high mem" on those boxes
+	 * that can support enough mem that a PCI device couldn't
+	 * directly DMA to any physical addresses.
+	 * ISA DMA support will need to revisit this.
+	 */
+	max_low_pfn = max_pfn;
+
+	/* reserve PAGE0 pdc memory, kernel text/data/bss & bootmap */
+
+#define PDC_CONSOLE_IO_IODC_SIZE 32768
+
+	memblock_reserve(0UL, (unsigned long)(PAGE0->mem_free +
+				PDC_CONSOLE_IO_IODC_SIZE));
+	memblock_reserve(__pa(KERNEL_BINARY_TEXT_START),
+			(unsigned long)(_end - KERNEL_BINARY_TEXT_START));
+
+#ifndef CONFIG_SPARSEMEM
+
+	/* reserve the holes */
+
+	for (i = 0; i < npmem_holes; i++) {
+		memblock_reserve((pmem_holes[i].start_pfn << PAGE_SHIFT),
+				(pmem_holes[i].pages << PAGE_SHIFT));
+	}
+#endif
+
+#ifdef CONFIG_BLK_DEV_INITRD
+	if (initrd_start) {
+		printk(KERN_INFO "initrd: %08lx-%08lx\n", initrd_start, initrd_end);
+		if (__pa(initrd_start) < mem_max) {
+			unsigned long initrd_reserve;
+
+			if (__pa(initrd_end) > mem_max) {
+				initrd_reserve = mem_max - __pa(initrd_start);
+			} else {
+				initrd_reserve = initrd_end - initrd_start;
+			}
+			initrd_below_start_ok = 1;
+			printk(KERN_INFO "initrd: reserving %08lx-%08lx (mem_max %08lx)\n", __pa(initrd_start), __pa(initrd_start) + initrd_reserve, mem_max);
+
+			memblock_reserve(__pa(initrd_start), initrd_reserve);
+		}
+	}
+#endif
+
+	data_resource.start =  virt_to_phys(&data_start);
+	data_resource.end = virt_to_phys(_end) - 1;
+	code_resource.start = virt_to_phys(_text);
+	code_resource.end = virt_to_phys(&data_start)-1;
+
+	/* We don't know which region the kernel will be in, so try
+	 * all of them.
+	 */
+	for (i = 0; i < sysram_resource_count; i++) {
+		struct resource *res = &sysram_resources[i];
+		request_resource(res, &code_resource);
+		request_resource(res, &data_resource);
+	}
+	request_resource(&sysram_resources[0], &pdcdata_resource);
+
+	/* Initialize Page Deallocation Table (PDT) and check for bad memory. */
+	pdc_pdt_init();
+
+	memblock_allow_resize();
+	memblock_dump_all();
+}
+
+static bool kernel_set_to_readonly;
+
+static void __ref map_pages(unsigned long start_vaddr,
+			    unsigned long start_paddr, unsigned long size,
+			    pgprot_t pgprot, int force)
+{
+	pmd_t *pmd;
+	pte_t *pg_table;
+	unsigned long end_paddr;
+	unsigned long start_pmd;
+	unsigned long start_pte;
+	unsigned long tmp1;
+	unsigned long tmp2;
+	unsigned long address;
+	unsigned long vaddr;
+	unsigned long ro_start;
+	unsigned long ro_end;
+	unsigned long kernel_start, kernel_end;
+
+	ro_start = __pa((unsigned long)_text);
+	ro_end   = __pa((unsigned long)&data_start);
+	kernel_start = __pa((unsigned long)&__init_begin);
+	kernel_end  = __pa((unsigned long)&_end);
+
+	end_paddr = start_paddr + size;
+
+	/* for 2-level configuration PTRS_PER_PMD is 0 so start_pmd will be 0 */
+	start_pmd = ((start_vaddr >> PMD_SHIFT) & (PTRS_PER_PMD - 1));
+	start_pte = ((start_vaddr >> PAGE_SHIFT) & (PTRS_PER_PTE - 1));
+
+	address = start_paddr;
+	vaddr = start_vaddr;
+	while (address < end_paddr) {
+		pgd_t *pgd = pgd_offset_k(vaddr);
+		p4d_t *p4d = p4d_offset(pgd, vaddr);
+		pud_t *pud = pud_offset(p4d, vaddr);
+
+#if CONFIG_PGTABLE_LEVELS == 3
+		if (pud_none(*pud)) {
+			pmd = memblock_alloc_or_panic(PAGE_SIZE << PMD_TABLE_ORDER,
+					     PAGE_SIZE << PMD_TABLE_ORDER);
+			pud_populate(NULL, pud, pmd);
+		}
+#endif
+
+		pmd = pmd_offset(pud, vaddr);
+		for (tmp1 = start_pmd; tmp1 < PTRS_PER_PMD; tmp1++, pmd++) {
+			if (pmd_none(*pmd)) {
+				pg_table = memblock_alloc_or_panic(PAGE_SIZE, PAGE_SIZE);
+				pmd_populate_kernel(NULL, pmd, pg_table);
+			}
+
+			pg_table = pte_offset_kernel(pmd, vaddr);
+			for (tmp2 = start_pte; tmp2 < PTRS_PER_PTE; tmp2++, pg_table++) {
+				pte_t pte;
+				pgprot_t prot;
+				bool huge = false;
+
+				if (force) {
+					prot = pgprot;
+				} else if (address < kernel_start || address >= kernel_end) {
+					/* outside kernel memory */
+					prot = PAGE_KERNEL;
+				} else if (!kernel_set_to_readonly) {
+					/* still initializing, allow writing to RO memory */
+					prot = PAGE_KERNEL_RWX;
+					huge = true;
+				} else if (address >= ro_start) {
+					/* Code (ro) and Data areas */
+					prot = (address < ro_end) ?
+						PAGE_KERNEL_EXEC : PAGE_KERNEL;
+					huge = true;
+				} else {
+					prot = PAGE_KERNEL;
+				}
+
+				pte = __mk_pte(address, prot);
+				if (huge)
+					pte = pte_mkhuge(pte);
+
+				if (address >= end_paddr)
+					break;
+
+				set_pte(pg_table, pte);
+
+				address += PAGE_SIZE;
+				vaddr += PAGE_SIZE;
+			}
+			start_pte = 0;
+
+			if (address >= end_paddr)
+			    break;
+		}
+		start_pmd = 0;
+	}
+}
+
+void __init set_kernel_text_rw(int enable_read_write)
+{
+	unsigned long start = (unsigned long) __init_begin;
+	unsigned long end   = (unsigned long) &data_start;
+
+	map_pages(start, __pa(start), end-start,
+		PAGE_KERNEL_RWX, enable_read_write ? 1:0);
+
+	/* force the kernel to see the new page table entries */
+	flush_cache_all();
+	flush_tlb_all();
+}
+
+void free_initmem(void)
+{
+	unsigned long init_begin = (unsigned long)__init_begin;
+	unsigned long init_end = (unsigned long)__init_end;
+	unsigned long kernel_end  = (unsigned long)&_end;
+
+	/* Remap kernel text and data, but do not touch init section yet. */
+	map_pages(init_end, __pa(init_end), kernel_end - init_end,
+		  PAGE_KERNEL, 0);
+
+	/* The init text pages are marked R-X.  We have to
+	 * flush the icache and mark them RW-
+	 *
+	 * Do a dummy remap of the data section first (the data
+	 * section is already PAGE_KERNEL) to pull in the TLB entries
+	 * for map_kernel */
+	map_pages(init_begin, __pa(init_begin), init_end - init_begin,
+		  PAGE_KERNEL_RWX, 1);
+	/* now remap at PAGE_KERNEL since the TLB is pre-primed to execute
+	 * map_pages */
+	map_pages(init_begin, __pa(init_begin), init_end - init_begin,
+		  PAGE_KERNEL, 1);
+
+	/* force the kernel to see the new TLB entries */
+	__flush_tlb_range(0, init_begin, kernel_end);
+
+	/* finally dump all the instructions which were cached, since the
+	 * pages are no-longer executable */
+	flush_icache_range(init_begin, init_end);
+
+	free_initmem_default(POISON_FREE_INITMEM);
+
+	/* set up a new led state on systems shipped LED State panel */
+	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_BCOMPLETE);
+}
+
+
+#ifdef CONFIG_STRICT_KERNEL_RWX
+void mark_rodata_ro(void)
+{
+	unsigned long start = (unsigned long) &__start_rodata;
+	unsigned long end = (unsigned long) &__end_rodata;
+
+	pr_info("Write protecting the kernel read-only data: %luk\n",
+	       (end - start) >> 10);
+
+	kernel_set_to_readonly = true;
+	map_pages(start, __pa(start), end - start, PAGE_KERNEL, 0);
+
+	/* force the kernel to see the new page table entries */
+	flush_cache_all();
+	flush_tlb_all();
+}
+#endif
+
+
+/*
+ * Just an arbitrary offset to serve as a "hole" between mapping areas
+ * (between top of physical memory and a potential pcxl dma mapping
+ * area, and below the vmalloc mapping area).
+ *
+ * The current 32K value just means that there will be a 32K "hole"
+ * between mapping areas. That means that  any out-of-bounds memory
+ * accesses will hopefully be caught. The vmalloc() routines leaves
+ * a hole of 4kB between each vmalloced area for the same reason.
+ */
+
+ /* Leave room for gateway page expansion */
+#if KERNEL_MAP_START < GATEWAY_PAGE_SIZE
+#error KERNEL_MAP_START is in gateway reserved region
+#endif
+#define MAP_START (KERNEL_MAP_START)
+
+#define VM_MAP_OFFSET  (32*1024)
+#define SET_MAP_OFFSET(x) ((void *)(((unsigned long)(x) + VM_MAP_OFFSET) \
+				     & ~(VM_MAP_OFFSET-1)))
+
+void *parisc_vmalloc_start __ro_after_init;
+EXPORT_SYMBOL(parisc_vmalloc_start);
+
+void __init mem_init(void)
+{
+	/* Do sanity checks on IPC (compat) structures */
+	BUILD_BUG_ON(sizeof(struct ipc64_perm) != 48);
+#ifndef CONFIG_64BIT
+	BUILD_BUG_ON(sizeof(struct semid64_ds) != 80);
+	BUILD_BUG_ON(sizeof(struct msqid64_ds) != 104);
+	BUILD_BUG_ON(sizeof(struct shmid64_ds) != 104);
+#endif
+#ifdef CONFIG_COMPAT
+	BUILD_BUG_ON(sizeof(struct compat_ipc64_perm) != sizeof(struct ipc64_perm));
+	BUILD_BUG_ON(sizeof(struct compat_semid64_ds) != 80);
+	BUILD_BUG_ON(sizeof(struct compat_msqid64_ds) != 104);
+	BUILD_BUG_ON(sizeof(struct compat_shmid64_ds) != 104);
+#endif
+
+	/* Do sanity checks on page table constants */
+	BUILD_BUG_ON(PTE_ENTRY_SIZE != sizeof(pte_t));
+	BUILD_BUG_ON(PMD_ENTRY_SIZE != sizeof(pmd_t));
+	BUILD_BUG_ON(PGD_ENTRY_SIZE != sizeof(pgd_t));
+	BUILD_BUG_ON(PAGE_SHIFT + BITS_PER_PTE + BITS_PER_PMD + BITS_PER_PGD
+			> BITS_PER_LONG);
+#if CONFIG_PGTABLE_LEVELS == 3
+	BUILD_BUG_ON(PT_INITIAL > PTRS_PER_PMD);
+#else
+	BUILD_BUG_ON(PT_INITIAL > PTRS_PER_PGD);
+#endif
+
+#ifdef CONFIG_64BIT
+	/* avoid ldil_%L() asm statements to sign-extend into upper 32-bits */
+	BUILD_BUG_ON(__PAGE_OFFSET >= 0x80000000);
+	BUILD_BUG_ON(TMPALIAS_MAP_START >= 0x80000000);
+#endif
+
+#ifdef CONFIG_PA11
+	if (boot_cpu_data.cpu_type == pcxl2 || boot_cpu_data.cpu_type == pcxl) {
+		pcxl_dma_start = (unsigned long)SET_MAP_OFFSET(MAP_START);
+		parisc_vmalloc_start = SET_MAP_OFFSET(pcxl_dma_start
+						+ PCXL_DMA_MAP_SIZE);
+	} else
+#endif
+		parisc_vmalloc_start = SET_MAP_OFFSET(MAP_START);
+
+#if 0
+	/*
+	 * Do not expose the virtual kernel memory layout to userspace.
+	 * But keep code for debugging purposes.
+	 */
+	printk("virtual kernel memory layout:\n"
+	       "     vmalloc : 0x%px - 0x%px   (%4ld MB)\n"
+	       "     fixmap  : 0x%px - 0x%px   (%4ld kB)\n"
+	       "     memory  : 0x%px - 0x%px   (%4ld MB)\n"
+	       "       .init : 0x%px - 0x%px   (%4ld kB)\n"
+	       "       .data : 0x%px - 0x%px   (%4ld kB)\n"
+	       "       .text : 0x%px - 0x%px   (%4ld kB)\n",
+
+	       (void*)VMALLOC_START, (void*)VMALLOC_END,
+	       (VMALLOC_END - VMALLOC_START) >> 20,
+
+	       (void *)FIXMAP_START, (void *)(FIXMAP_START + FIXMAP_SIZE),
+	       (unsigned long)(FIXMAP_SIZE / 1024),
+
+	       __va(0), high_memory,
+	       ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20,
+
+	       __init_begin, __init_end,
+	       ((unsigned long)__init_end - (unsigned long)__init_begin) >> 10,
+
+	       _etext, _edata,
+	       ((unsigned long)_edata - (unsigned long)_etext) >> 10,
+
+	       _text, _etext,
+	       ((unsigned long)_etext - (unsigned long)_text) >> 10);
+#endif
+}
+
+/*
+ * pagetable_init() sets up the page tables
+ *
+ * Note that gateway_init() places the Linux gateway page at page 0.
+ * Since gateway pages cannot be dereferenced this has the desirable
+ * side effect of trapping those pesky NULL-reference errors in the
+ * kernel.
+ */
+static void __init pagetable_init(void)
+{
+	int range;
+
+	/* Map each physical memory range to its kernel vaddr */
+
+	for (range = 0; range < npmem_ranges; range++) {
+		unsigned long start_paddr;
+		unsigned long size;
+
+		start_paddr = pmem_ranges[range].start_pfn << PAGE_SHIFT;
+		size = pmem_ranges[range].pages << PAGE_SHIFT;
+
+		map_pages((unsigned long)__va(start_paddr), start_paddr,
+			  size, PAGE_KERNEL, 0);
+	}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+	if (initrd_end && initrd_end > mem_limit) {
+		printk(KERN_INFO "initrd: mapping %08lx-%08lx\n", initrd_start, initrd_end);
+		map_pages(initrd_start, __pa(initrd_start),
+			  initrd_end - initrd_start, PAGE_KERNEL, 0);
+	}
+#endif
+}
+
+static void __init gateway_init(void)
+{
+	unsigned long linux_gateway_page_addr;
+	/* FIXME: This is 'const' in order to trick the compiler
+	   into not treating it as DP-relative data. */
+	extern void * const linux_gateway_page;
+
+	linux_gateway_page_addr = LINUX_GATEWAY_ADDR & PAGE_MASK;
+
+	/*
+	 * Setup Linux Gateway page.
+	 *
+	 * The Linux gateway page will reside in kernel space (on virtual
+	 * page 0), so it doesn't need to be aliased into user space.
+	 */
+
+	map_pages(linux_gateway_page_addr, __pa(&linux_gateway_page),
+		  PAGE_SIZE, PAGE_GATEWAY, 1);
+}
+
+static void __init fixmap_init(void)
+{
+	unsigned long addr = FIXMAP_START;
+	unsigned long end = FIXMAP_START + FIXMAP_SIZE;
+	pgd_t *pgd = pgd_offset_k(addr);
+	p4d_t *p4d = p4d_offset(pgd, addr);
+	pud_t *pud = pud_offset(p4d, addr);
+	pmd_t *pmd;
+
+	BUILD_BUG_ON(FIXMAP_SIZE > PMD_SIZE);
+
+#if CONFIG_PGTABLE_LEVELS == 3
+	if (pud_none(*pud)) {
+		pmd = memblock_alloc_or_panic(PAGE_SIZE << PMD_TABLE_ORDER,
+				     PAGE_SIZE << PMD_TABLE_ORDER);
+		pud_populate(NULL, pud, pmd);
+	}
+#endif
+
+	pmd = pmd_offset(pud, addr);
+	do {
+		pte_t *pte = memblock_alloc_or_panic(PAGE_SIZE, PAGE_SIZE);
+
+		pmd_populate_kernel(&init_mm, pmd, pte);
+
+		addr += PAGE_SIZE;
+	} while (addr < end);
+}
+
+void __init arch_zone_limits_init(unsigned long *max_zone_pfns)
+{
+	max_zone_pfns[ZONE_NORMAL] = PFN_DOWN(memblock_end_of_DRAM());
+}
+
+void __init paging_init(void)
+{
+	setup_bootmem();
+	pagetable_init();
+	gateway_init();
+	fixmap_init();
+	flush_cache_all_local(); /* start with known state */
+	flush_tlb_all_local(NULL);
+}
+
+static void alloc_btlb(unsigned long start, unsigned long end, int *slot,
+			unsigned long entry_info)
+{
+	const int slot_max = btlb_info.fixed_range_info.num_comb;
+	int min_num_pages = btlb_info.min_size;
+	unsigned long size;
+
+	/* map at minimum 4 pages */
+	if (min_num_pages < 4)
+		min_num_pages = 4;
+
+	size = HUGEPAGE_SIZE;
+	while (start < end && *slot < slot_max && size >= PAGE_SIZE) {
+		/* starting address must have same alignment as size! */
+		/* if correctly aligned and fits in double size, increase */
+		if (((start & (2 * size - 1)) == 0) &&
+		    (end - start) >= (2 * size)) {
+			size <<= 1;
+			continue;
+		}
+		/* if current size alignment is too big, try smaller size */
+		if ((start & (size - 1)) != 0) {
+			size >>= 1;
+			continue;
+		}
+		if ((end - start) >= size) {
+			if ((size >> PAGE_SHIFT) >= min_num_pages)
+				pdc_btlb_insert(start >> PAGE_SHIFT, __pa(start) >> PAGE_SHIFT,
+					size >> PAGE_SHIFT, entry_info, *slot);
+			(*slot)++;
+			start += size;
+			continue;
+		}
+		size /= 2;
+		continue;
+	}
+}
+
+void btlb_init_per_cpu(void)
+{
+	unsigned long s, t, e;
+	int slot;
+
+	/* BTLBs are not available on 64-bit CPUs */
+	if (IS_ENABLED(CONFIG_PA20))
+		return;
+	else if (pdc_btlb_info(&btlb_info) < 0) {
+		memset(&btlb_info, 0, sizeof btlb_info);
+	}
+
+	/* insert BLTLBs for code and data segments */
+	s = (uintptr_t) dereference_function_descriptor(&_stext);
+	e = (uintptr_t) dereference_function_descriptor(&_etext);
+	t = (uintptr_t) dereference_function_descriptor(&_sdata);
+	BUG_ON(t != e);
+
+	/* code segments */
+	slot = 0;
+	alloc_btlb(s, e, &slot, 0x13800000);
+
+	/* sanity check */
+	t = (uintptr_t) dereference_function_descriptor(&_edata);
+	e = (uintptr_t) dereference_function_descriptor(&__bss_start);
+	BUG_ON(t != e);
+
+	/* data segments */
+	s = (uintptr_t) dereference_function_descriptor(&_sdata);
+	e = (uintptr_t) dereference_function_descriptor(&__bss_stop);
+	alloc_btlb(s, e, &slot, 0x11800000);
+}
+
+#ifdef CONFIG_PA20
+
+/*
+ * Currently, all PA20 chips have 18 bit protection IDs, which is the
+ * limiting factor (space ids are 32 bits).
+ */
+
+#define NR_SPACE_IDS 262144
+
+#else
+
+/*
+ * Currently we have a one-to-one relationship between space IDs and
+ * protection IDs. Older parisc chips (PCXS, PCXT, PCXL, PCXL2) only
+ * support 15 bit protection IDs, so that is the limiting factor.
+ * PCXT' has 18 bit protection IDs, but only 16 bit spaceids, so it's
+ * probably not worth the effort for a special case here.
+ */
+
+#define NR_SPACE_IDS 32768
+
+#endif  /* !CONFIG_PA20 */
+
+#define RECYCLE_THRESHOLD (NR_SPACE_IDS / 2)
+#define SID_ARRAY_SIZE  (NR_SPACE_IDS / (8 * sizeof(long)))
+
+static unsigned long space_id[SID_ARRAY_SIZE] = { 1 }; /* disallow space 0 */
+static unsigned long dirty_space_id[SID_ARRAY_SIZE];
+static unsigned long space_id_index;
+static unsigned long free_space_ids = NR_SPACE_IDS - 1;
+static unsigned long dirty_space_ids;
+
+static DEFINE_SPINLOCK(sid_lock);
+
+unsigned long alloc_sid(void)
+{
+	unsigned long index;
+
+	spin_lock(&sid_lock);
+
+	if (free_space_ids == 0) {
+		if (dirty_space_ids != 0) {
+			spin_unlock(&sid_lock);
+			flush_tlb_all(); /* flush_tlb_all() calls recycle_sids() */
+			spin_lock(&sid_lock);
+		}
+		BUG_ON(free_space_ids == 0);
+	}
+
+	free_space_ids--;
+
+	index = find_next_zero_bit(space_id, NR_SPACE_IDS, space_id_index);
+	space_id[BIT_WORD(index)] |= BIT_MASK(index);
+	space_id_index = index;
+
+	spin_unlock(&sid_lock);
+
+	return index << SPACEID_SHIFT;
+}
+
+void free_sid(unsigned long spaceid)
+{
+	unsigned long index = spaceid >> SPACEID_SHIFT;
+	unsigned long *dirty_space_offset, mask;
+
+	dirty_space_offset = &dirty_space_id[BIT_WORD(index)];
+	mask = BIT_MASK(index);
+
+	spin_lock(&sid_lock);
+
+	BUG_ON(*dirty_space_offset & mask); /* attempt to free space id twice */
+
+	*dirty_space_offset |= mask;
+	dirty_space_ids++;
+
+	spin_unlock(&sid_lock);
+}
+
+
+#ifdef CONFIG_SMP
+static void get_dirty_sids(unsigned long *ndirtyptr,unsigned long *dirty_array)
+{
+	int i;
+
+	/* NOTE: sid_lock must be held upon entry */
+
+	*ndirtyptr = dirty_space_ids;
+	if (dirty_space_ids != 0) {
+	    for (i = 0; i < SID_ARRAY_SIZE; i++) {
+		dirty_array[i] = dirty_space_id[i];
+		dirty_space_id[i] = 0;
+	    }
+	    dirty_space_ids = 0;
+	}
+
+	return;
+}
+
+static void recycle_sids(unsigned long ndirty,unsigned long *dirty_array)
+{
+	int i;
+
+	/* NOTE: sid_lock must be held upon entry */
+
+	if (ndirty != 0) {
+		for (i = 0; i < SID_ARRAY_SIZE; i++) {
+			space_id[i] ^= dirty_array[i];
+		}
+
+		free_space_ids += ndirty;
+		space_id_index = 0;
+	}
+}
+
+#else /* CONFIG_SMP */
+
+static void recycle_sids(void)
+{
+	int i;
+
+	/* NOTE: sid_lock must be held upon entry */
+
+	if (dirty_space_ids != 0) {
+		for (i = 0; i < SID_ARRAY_SIZE; i++) {
+			space_id[i] ^= dirty_space_id[i];
+			dirty_space_id[i] = 0;
+		}
+
+		free_space_ids += dirty_space_ids;
+		dirty_space_ids = 0;
+		space_id_index = 0;
+	}
+}
+#endif
+
+/*
+ * flush_tlb_all() calls recycle_sids(), since whenever the entire tlb is
+ * purged, we can safely reuse the space ids that were released but
+ * not flushed from the tlb.
+ */
+
+#ifdef CONFIG_SMP
+
+static unsigned long recycle_ndirty;
+static unsigned long recycle_dirty_array[SID_ARRAY_SIZE];
+static unsigned int recycle_inuse;
+
+void flush_tlb_all(void)
+{
+	int do_recycle;
+
+	do_recycle = 0;
+	spin_lock(&sid_lock);
+	__inc_irq_stat(irq_tlb_count);
+	if (dirty_space_ids > RECYCLE_THRESHOLD) {
+	    BUG_ON(recycle_inuse);  /* FIXME: Use a semaphore/wait queue here */
+	    get_dirty_sids(&recycle_ndirty,recycle_dirty_array);
+	    recycle_inuse++;
+	    do_recycle++;
+	}
+	spin_unlock(&sid_lock);
+	on_each_cpu(flush_tlb_all_local, NULL, 1);
+	if (do_recycle) {
+	    spin_lock(&sid_lock);
+	    recycle_sids(recycle_ndirty,recycle_dirty_array);
+	    recycle_inuse = 0;
+	    spin_unlock(&sid_lock);
+	}
+}
+#else
+void flush_tlb_all(void)
+{
+	spin_lock(&sid_lock);
+	__inc_irq_stat(irq_tlb_count);
+	flush_tlb_all_local(NULL);
+	recycle_sids();
+	spin_unlock(&sid_lock);
+}
+#endif
+
+static const pgprot_t protection_map[16] = {
+	[VM_NONE]					= PAGE_NONE,
+	[VM_READ]					= PAGE_READONLY,
+	[VM_WRITE]					= PAGE_NONE,
+	[VM_WRITE | VM_READ]				= PAGE_READONLY,
+	[VM_EXEC]					= PAGE_EXECREAD,
+	[VM_EXEC | VM_READ]				= PAGE_EXECREAD,
+	[VM_EXEC | VM_WRITE]				= PAGE_EXECREAD,
+	[VM_EXEC | VM_WRITE | VM_READ]			= PAGE_EXECREAD,
+	[VM_SHARED]					= PAGE_NONE,
+	[VM_SHARED | VM_READ]				= PAGE_READONLY,
+	[VM_SHARED | VM_WRITE]				= PAGE_WRITEONLY,
+	[VM_SHARED | VM_WRITE | VM_READ]		= PAGE_SHARED,
+	[VM_SHARED | VM_EXEC]				= PAGE_EXECREAD,
+	[VM_SHARED | VM_EXEC | VM_READ]			= PAGE_EXECREAD,
+	[VM_SHARED | VM_EXEC | VM_WRITE]		= PAGE_RWX,
+	[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= PAGE_RWX
+};
+DECLARE_VM_GET_PAGE_PROT
+
+#ifdef CONFIG_EXECMEM
+static struct execmem_info execmem_info __ro_after_init;
+
+struct execmem_info __init *execmem_arch_setup(void)
+{
+	execmem_info = (struct execmem_info){
+		.ranges = {
+			[EXECMEM_DEFAULT] = {
+				.start	= VMALLOC_START,
+				.end	= VMALLOC_END,
+				.pgprot	= PAGE_KERNEL_RWX,
+				.alignment = 1,
+			},
+		},
+	};
+
+	return &execmem_info;
+}
+#endif /* CONFIG_EXECMEM */

linux-7.2.3/arch/parisc/mm/ioremap.c

@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * arch/parisc/mm/ioremap.c
+ *
+ * (C) Copyright 1995 1996 Linus Torvalds
+ * (C) Copyright 2001-2019 Helge Deller <deller@gmx.de>
+ * (C) Copyright 2005 Kyle McMartin <kyle@parisc-linux.org>
+ */
+
+#include <linux/vmalloc.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/mm.h>
+
+void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
+			   pgprot_t prot)
+{
+#ifdef CONFIG_EISA
+	unsigned long end = phys_addr + size - 1;
+	/* Support EISA addresses */
+	if ((phys_addr >= 0x00080000 && end < 0x000fffff) ||
+	    (phys_addr >= 0x00500000 && end < 0x03bfffff))
+		phys_addr |= F_EXTEND(0xfc000000);
+#endif
+
+	/*
+	 * Don't allow anybody to remap normal RAM that we're using..
+	 */
+	if (phys_addr < virt_to_phys(high_memory)) {
+		char *t_addr, *t_end;
+		struct page *page;
+
+		t_addr = __va(phys_addr);
+		t_end = t_addr + (size - 1);
+	   
+		for (page = virt_to_page(t_addr); 
+		     page <= virt_to_page(t_end); page++) {
+			if(!PageReserved(page))
+				return NULL;
+		}
+	}
+
+	return generic_ioremap_prot(phys_addr, size, prot);
+}
+EXPORT_SYMBOL(ioremap_prot);