Resguardo inicial

linux-7.2.3/drivers/acpi/riscv/Kconfig

@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# ACPI Configuration for RISC-V
+#
+
+config ACPI_RIMT
+	bool

linux-7.2.3/drivers/acpi/riscv/Makefile

@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-y					+= rhct.o init.o irq.o
+obj-$(CONFIG_ACPI_PROCESSOR_IDLE)	+= cpuidle.o
+obj-$(CONFIG_ACPI_CPPC_LIB)		+= cppc.o
+obj-$(CONFIG_ACPI_RIMT)			+= rimt.o

linux-7.2.3/drivers/acpi/riscv/cppc.c

@@ -0,0 +1,155 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Implement CPPC FFH helper routines for RISC-V.
+ *
+ * Copyright (C) 2024 Ventana Micro Systems Inc.
+ */
+
+#include <acpi/cppc_acpi.h>
+#include <asm/csr.h>
+#include <asm/sbi.h>
+
+#define SBI_EXT_CPPC 0x43505043
+
+/* CPPC interfaces defined in SBI spec */
+#define SBI_CPPC_PROBE			0x0
+#define SBI_CPPC_READ			0x1
+#define SBI_CPPC_READ_HI		0x2
+#define SBI_CPPC_WRITE			0x3
+
+/* RISC-V FFH definitions from RISC-V FFH spec */
+#define FFH_CPPC_TYPE(r)		(((r) & GENMASK_ULL(63, 60)) >> 60)
+#define FFH_CPPC_SBI_REG(r)		((r) & GENMASK(31, 0))
+#define FFH_CPPC_CSR_NUM(r)		((r) & GENMASK(11, 0))
+
+#define FFH_CPPC_SBI			0x1
+#define FFH_CPPC_CSR			0x2
+
+struct sbi_cppc_data {
+	u64 val;
+	u32 reg;
+	struct sbiret ret;
+};
+
+static bool cppc_ext_present;
+
+static int __init sbi_cppc_init(void)
+{
+	if (sbi_spec_version >= sbi_mk_version(2, 0) &&
+	    sbi_probe_extension(SBI_EXT_CPPC) > 0) {
+		cppc_ext_present = true;
+	} else {
+		cppc_ext_present = false;
+	}
+
+	return 0;
+}
+device_initcall(sbi_cppc_init);
+
+static void sbi_cppc_read(void *read_data)
+{
+	struct sbi_cppc_data *data = (struct sbi_cppc_data *)read_data;
+
+	data->ret = sbi_ecall(SBI_EXT_CPPC, SBI_CPPC_READ,
+			      data->reg, 0, 0, 0, 0, 0);
+}
+
+static void sbi_cppc_write(void *write_data)
+{
+	struct sbi_cppc_data *data = (struct sbi_cppc_data *)write_data;
+
+	data->ret = sbi_ecall(SBI_EXT_CPPC, SBI_CPPC_WRITE,
+			      data->reg, data->val, 0, 0, 0, 0);
+}
+
+static void cppc_ffh_csr_read(void *read_data)
+{
+	struct sbi_cppc_data *data = (struct sbi_cppc_data *)read_data;
+
+	switch (data->reg) {
+	/* Support only TIME CSR for now */
+	case CSR_TIME:
+		data->ret.value = csr_read(CSR_TIME);
+		data->ret.error = 0;
+		break;
+	default:
+		data->ret.error = -EINVAL;
+		break;
+	}
+}
+
+static void cppc_ffh_csr_write(void *write_data)
+{
+	struct sbi_cppc_data *data = (struct sbi_cppc_data *)write_data;
+
+	data->ret.error = -EINVAL;
+}
+
+/*
+ * Refer to drivers/acpi/cppc_acpi.c for the description of the functions
+ * below.
+ */
+bool cpc_ffh_supported(void)
+{
+	return true;
+}
+
+int cpc_read_ffh(int cpu, struct cpc_reg *reg, u64 *val)
+{
+	struct sbi_cppc_data data;
+
+	if (WARN_ON_ONCE(irqs_disabled()))
+		return -EPERM;
+
+	if (FFH_CPPC_TYPE(reg->address) == FFH_CPPC_SBI) {
+		if (!cppc_ext_present)
+			return -EINVAL;
+
+		data.reg = FFH_CPPC_SBI_REG(reg->address);
+
+		smp_call_function_single(cpu, sbi_cppc_read, &data, 1);
+
+		*val = data.ret.value;
+
+		return (data.ret.error) ? sbi_err_map_linux_errno(data.ret.error) : 0;
+	} else if (FFH_CPPC_TYPE(reg->address) == FFH_CPPC_CSR) {
+		data.reg = FFH_CPPC_CSR_NUM(reg->address);
+
+		smp_call_function_single(cpu, cppc_ffh_csr_read, &data, 1);
+
+		*val = data.ret.value;
+
+		return data.ret.error;
+	}
+
+	return -EINVAL;
+}
+
+int cpc_write_ffh(int cpu, struct cpc_reg *reg, u64 val)
+{
+	struct sbi_cppc_data data;
+
+	if (WARN_ON_ONCE(irqs_disabled()))
+		return -EPERM;
+
+	if (FFH_CPPC_TYPE(reg->address) == FFH_CPPC_SBI) {
+		if (!cppc_ext_present)
+			return -EINVAL;
+
+		data.reg = FFH_CPPC_SBI_REG(reg->address);
+		data.val = val;
+
+		smp_call_function_single(cpu, sbi_cppc_write, &data, 1);
+
+		return (data.ret.error) ? sbi_err_map_linux_errno(data.ret.error) : 0;
+	} else if (FFH_CPPC_TYPE(reg->address) == FFH_CPPC_CSR) {
+		data.reg = FFH_CPPC_CSR_NUM(reg->address);
+		data.val = val;
+
+		smp_call_function_single(cpu, cppc_ffh_csr_write, &data, 1);
+
+		return data.ret.error;
+	}
+
+	return -EINVAL;
+}

linux-7.2.3/drivers/acpi/riscv/cpuidle.c

@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2024, Ventana Micro Systems Inc
+ *	Author: Sunil V L <sunilvl@ventanamicro.com>
+ *
+ */
+
+#include <linux/acpi.h>
+#include <acpi/processor.h>
+#include <linux/cpu_pm.h>
+#include <linux/cpuidle.h>
+#include <linux/suspend.h>
+#include <asm/cpuidle.h>
+#include <asm/sbi.h>
+#include <asm/suspend.h>
+
+#define RISCV_FFH_LPI_TYPE_MASK	GENMASK_ULL(63, 60)
+#define RISCV_FFH_LPI_RSVD_MASK	GENMASK_ULL(59, 32)
+
+#define RISCV_FFH_LPI_TYPE_SBI	BIT_ULL(60)
+
+static int acpi_cpu_init_idle(unsigned int cpu)
+{
+	int i;
+	struct acpi_lpi_state *lpi;
+	struct acpi_processor *pr = per_cpu(processors, cpu);
+
+	if (unlikely(!pr || !pr->flags.has_lpi))
+		return -EINVAL;
+
+	if (!riscv_sbi_hsm_is_supported())
+		return -ENODEV;
+
+	if (pr->power.count <= 1)
+		return -ENODEV;
+
+	for (i = 1; i < pr->power.count; i++) {
+		u32 state;
+
+		lpi = &pr->power.lpi_states[i];
+
+		/*
+		 * Validate Entry Method as per FFH spec.
+		 * bits[63:60] should be 0x1
+		 * bits[59:32] should be 0x0
+		 * bits[31:0] represent a SBI power_state
+		 */
+		if (((lpi->address & RISCV_FFH_LPI_TYPE_MASK) != RISCV_FFH_LPI_TYPE_SBI) ||
+		    (lpi->address & RISCV_FFH_LPI_RSVD_MASK)) {
+			pr_warn("Invalid LPI entry method %#llx\n", lpi->address);
+			return -EINVAL;
+		}
+
+		state = lpi->address;
+		if (!riscv_sbi_suspend_state_is_valid(state)) {
+			pr_warn("Invalid SBI power state %#x\n", state);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+int acpi_processor_ffh_lpi_probe(unsigned int cpu)
+{
+	return acpi_cpu_init_idle(cpu);
+}
+
+int __cpuidle acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
+{
+	u32 state = lpi->address;
+
+	if (state & SBI_HSM_SUSP_NON_RET_BIT)
+		return CPU_PM_CPU_IDLE_ENTER_PARAM(riscv_sbi_hart_suspend,
+						   lpi->index,
+						   state);
+	else
+		return CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM(riscv_sbi_hart_suspend,
+							     lpi->index,
+							     state);
+}

linux-7.2.3/drivers/acpi/riscv/init.c

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2023-2024, Ventana Micro Systems Inc
+ *	Author: Sunil V L <sunilvl@ventanamicro.com>
+ */
+
+#include <linux/acpi.h>
+#include "init.h"
+
+void __init acpi_arch_init(void)
+{
+	riscv_acpi_init_gsi_mapping();
+	if (IS_ENABLED(CONFIG_ACPI_RIMT))
+		riscv_acpi_rimt_init();
+}

linux-7.2.3/drivers/acpi/riscv/init.h

@@ -0,0 +1,5 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#include <linux/init.h>
+
+void __init riscv_acpi_init_gsi_mapping(void);
+void __init riscv_acpi_rimt_init(void);

linux-7.2.3/drivers/acpi/riscv/irq.c

@@ -0,0 +1,406 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2023-2024, Ventana Micro Systems Inc
+ *	Author: Sunil V L <sunilvl@ventanamicro.com>
+ */
+
+#include <linux/acpi.h>
+#include <linux/sort.h>
+#include <linux/irq.h>
+
+#include "init.h"
+
+#define RISCV_ACPI_INTC_FLAG_PENDING BIT(0)
+
+struct riscv_ext_intc_list {
+	acpi_handle		handle;
+	u32			gsi_base;
+	u32			nr_irqs;
+	u32			nr_idcs;
+	u32			id;
+	u32			type;
+	u32			flag;
+	struct list_head	list;
+};
+
+struct acpi_irq_dep_ctx {
+	int		rc;
+	unsigned int	index;
+	acpi_handle	handle;
+};
+
+LIST_HEAD(ext_intc_list);
+
+static int irqchip_cmp_func(const void *in0, const void *in1)
+{
+	struct acpi_probe_entry *elem0 = (struct acpi_probe_entry *)in0;
+	struct acpi_probe_entry *elem1 = (struct acpi_probe_entry *)in1;
+
+	return (elem0->type > elem1->type) - (elem0->type < elem1->type);
+}
+
+/*
+ * On RISC-V, RINTC structures in MADT should be probed before any other
+ * interrupt controller structures and IMSIC before APLIC. The interrupt
+ * controller subtypes in MADT of ACPI spec for RISC-V are defined in
+ * the incremental order like RINTC(24)->IMSIC(25)->APLIC(26)->PLIC(27).
+ * Hence, simply sorting the subtypes in incremental order will
+ * establish the required order.
+ */
+void arch_sort_irqchip_probe(struct acpi_probe_entry *ap_head, int nr)
+{
+	struct acpi_probe_entry *ape = ap_head;
+
+	if (nr == 1 || !ACPI_COMPARE_NAMESEG(ACPI_SIG_MADT, ape->id))
+		return;
+	sort(ape, nr, sizeof(*ape), irqchip_cmp_func, NULL);
+}
+
+static acpi_status riscv_acpi_update_gsi_handle(u32 gsi_base, acpi_handle handle)
+{
+	struct riscv_ext_intc_list *ext_intc_element;
+	struct list_head *i, *tmp;
+
+	list_for_each_safe(i, tmp, &ext_intc_list) {
+		ext_intc_element = list_entry(i, struct riscv_ext_intc_list, list);
+		if (gsi_base == ext_intc_element->gsi_base) {
+			ext_intc_element->handle = handle;
+			return AE_OK;
+		}
+	}
+
+	return AE_NOT_FOUND;
+}
+
+int riscv_acpi_update_gsi_range(u32 gsi_base, u32 nr_irqs)
+{
+	struct riscv_ext_intc_list *ext_intc_element;
+
+	list_for_each_entry(ext_intc_element, &ext_intc_list, list) {
+		if (gsi_base == ext_intc_element->gsi_base &&
+		    (ext_intc_element->flag & RISCV_ACPI_INTC_FLAG_PENDING)) {
+			ext_intc_element->nr_irqs = nr_irqs;
+			ext_intc_element->flag &= ~RISCV_ACPI_INTC_FLAG_PENDING;
+			return 0;
+		}
+	}
+
+	return -ENODEV;
+}
+
+int riscv_acpi_get_gsi_info(struct fwnode_handle *fwnode, u32 *gsi_base,
+			    u32 *id, u32 *nr_irqs, u32 *nr_idcs)
+{
+	struct riscv_ext_intc_list *ext_intc_element;
+	struct list_head *i;
+
+	list_for_each(i, &ext_intc_list) {
+		ext_intc_element = list_entry(i, struct riscv_ext_intc_list, list);
+		if (ext_intc_element->handle == ACPI_HANDLE_FWNODE(fwnode)) {
+			*gsi_base = ext_intc_element->gsi_base;
+			*id = ext_intc_element->id;
+			*nr_irqs = ext_intc_element->nr_irqs;
+			if (nr_idcs)
+				*nr_idcs = ext_intc_element->nr_idcs;
+
+			return 0;
+		}
+	}
+
+	return -ENODEV;
+}
+
+struct fwnode_handle *riscv_acpi_get_gsi_domain_id(u32 gsi)
+{
+	struct riscv_ext_intc_list *ext_intc_element;
+	struct acpi_device *adev;
+	struct list_head *i;
+
+	list_for_each(i, &ext_intc_list) {
+		ext_intc_element = list_entry(i, struct riscv_ext_intc_list, list);
+		if (gsi >= ext_intc_element->gsi_base &&
+		    gsi < (ext_intc_element->gsi_base + ext_intc_element->nr_irqs)) {
+			adev = acpi_fetch_acpi_dev(ext_intc_element->handle);
+			if (!adev)
+				return NULL;
+
+			return acpi_fwnode_handle(adev);
+		}
+	}
+
+	return NULL;
+}
+
+static int __init riscv_acpi_register_ext_intc(u32 gsi_base, u32 nr_irqs, u32 nr_idcs,
+					       u32 id, u32 type)
+{
+	struct riscv_ext_intc_list *ext_intc_element, *node, *prev;
+
+	ext_intc_element = kzalloc_obj(*ext_intc_element);
+	if (!ext_intc_element)
+		return -ENOMEM;
+
+	ext_intc_element->gsi_base = gsi_base;
+
+	/* If nr_irqs is zero, indicate it in flag and set to max range possible */
+	if (nr_irqs) {
+		ext_intc_element->nr_irqs = nr_irqs;
+	} else {
+		ext_intc_element->flag |= RISCV_ACPI_INTC_FLAG_PENDING;
+		ext_intc_element->nr_irqs = U32_MAX - ext_intc_element->gsi_base;
+	}
+
+	ext_intc_element->nr_idcs = nr_idcs;
+	ext_intc_element->id = id;
+	list_for_each_entry(node, &ext_intc_list, list) {
+		if (node->gsi_base < ext_intc_element->gsi_base)
+			break;
+	}
+
+	/* Adjust the previous node's GSI range if that has pending registration */
+	prev = list_prev_entry(node, list);
+	if (!list_entry_is_head(prev, &ext_intc_list, list)) {
+		if (prev->flag & RISCV_ACPI_INTC_FLAG_PENDING)
+			prev->nr_irqs = ext_intc_element->gsi_base - prev->gsi_base;
+	}
+
+	list_add_tail(&ext_intc_element->list, &node->list);
+	return 0;
+}
+
+static acpi_status __init riscv_acpi_create_gsi_map_smsi(acpi_handle handle, u32 level,
+							 void *context, void **return_value)
+{
+	acpi_status status;
+	u64 gbase;
+
+	if (!acpi_has_method(handle, "_GSB")) {
+		acpi_handle_err(handle, "_GSB method not found\n");
+		return AE_ERROR;
+	}
+
+	status = acpi_evaluate_integer(handle, "_GSB", NULL, &gbase);
+	if (ACPI_FAILURE(status)) {
+		acpi_handle_err(handle, "failed to evaluate _GSB method\n");
+		return status;
+	}
+
+	riscv_acpi_register_ext_intc(gbase, 0, 0, 0, ACPI_RISCV_IRQCHIP_SMSI);
+	status = riscv_acpi_update_gsi_handle((u32)gbase, handle);
+	if (ACPI_FAILURE(status)) {
+		acpi_handle_err(handle, "failed to find the GSI mapping entry\n");
+		return status;
+	}
+
+	return AE_OK;
+}
+
+static acpi_status __init riscv_acpi_create_gsi_map(acpi_handle handle, u32 level,
+						    void *context, void **return_value)
+{
+	acpi_status status;
+	u64 gbase;
+
+	if (!acpi_has_method(handle, "_GSB")) {
+		acpi_handle_err(handle, "_GSB method not found\n");
+		return AE_ERROR;
+	}
+
+	status = acpi_evaluate_integer(handle, "_GSB", NULL, &gbase);
+	if (ACPI_FAILURE(status)) {
+		acpi_handle_err(handle, "failed to evaluate _GSB method\n");
+		return status;
+	}
+
+	status = riscv_acpi_update_gsi_handle((u32)gbase, handle);
+	if (ACPI_FAILURE(status)) {
+		acpi_handle_err(handle, "failed to find the GSI mapping entry\n");
+		return status;
+	}
+
+	return AE_OK;
+}
+
+static int __init riscv_acpi_aplic_parse_madt(union acpi_subtable_headers *header,
+					      const unsigned long end)
+{
+	struct acpi_madt_aplic *aplic = (struct acpi_madt_aplic *)header;
+
+	return riscv_acpi_register_ext_intc(aplic->gsi_base, aplic->num_sources, aplic->num_idcs,
+					    aplic->id, ACPI_RISCV_IRQCHIP_APLIC);
+}
+
+static int __init riscv_acpi_plic_parse_madt(union acpi_subtable_headers *header,
+					     const unsigned long end)
+{
+	struct acpi_madt_plic *plic = (struct acpi_madt_plic *)header;
+
+	return riscv_acpi_register_ext_intc(plic->gsi_base, plic->num_irqs, 0,
+					    plic->id, ACPI_RISCV_IRQCHIP_PLIC);
+}
+
+void __init riscv_acpi_init_gsi_mapping(void)
+{
+	/* There can be either PLIC or APLIC */
+	if (acpi_table_parse_madt(ACPI_MADT_TYPE_PLIC, riscv_acpi_plic_parse_madt, 0) > 0) {
+		acpi_get_devices("RSCV0001", riscv_acpi_create_gsi_map, NULL, NULL);
+		return;
+	}
+
+	if (acpi_table_parse_madt(ACPI_MADT_TYPE_APLIC, riscv_acpi_aplic_parse_madt, 0) > 0)
+		acpi_get_devices("RSCV0002", riscv_acpi_create_gsi_map, NULL, NULL);
+
+	/* Unlike PLIC/APLIC, SYSMSI doesn't have MADT */
+	acpi_get_devices("RSCV0006", riscv_acpi_create_gsi_map_smsi, NULL, NULL);
+}
+
+static acpi_handle riscv_acpi_get_gsi_handle(u32 gsi)
+{
+	struct riscv_ext_intc_list *ext_intc_element;
+	struct list_head *i;
+
+	list_for_each(i, &ext_intc_list) {
+		ext_intc_element = list_entry(i, struct riscv_ext_intc_list, list);
+		if (gsi >= ext_intc_element->gsi_base &&
+		    gsi < (ext_intc_element->gsi_base + ext_intc_element->nr_irqs))
+			return ext_intc_element->handle;
+	}
+
+	return NULL;
+}
+
+static acpi_status riscv_acpi_irq_get_parent(struct acpi_resource *ares, void *context)
+{
+	struct acpi_irq_dep_ctx *ctx = context;
+	struct acpi_resource_irq *irq;
+	struct acpi_resource_extended_irq *eirq;
+
+	switch (ares->type) {
+	case ACPI_RESOURCE_TYPE_IRQ:
+		irq = &ares->data.irq;
+		if (ctx->index >= irq->interrupt_count) {
+			ctx->index -= irq->interrupt_count;
+			return AE_OK;
+		}
+		ctx->handle = riscv_acpi_get_gsi_handle(irq->interrupts[ctx->index]);
+		return AE_CTRL_TERMINATE;
+	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
+		eirq = &ares->data.extended_irq;
+		if (eirq->producer_consumer == ACPI_PRODUCER)
+			return AE_OK;
+
+		if (ctx->index >= eirq->interrupt_count) {
+			ctx->index -= eirq->interrupt_count;
+			return AE_OK;
+		}
+
+		/* Support GSIs only */
+		if (eirq->resource_source.string_length)
+			return AE_OK;
+
+		ctx->handle = riscv_acpi_get_gsi_handle(eirq->interrupts[ctx->index]);
+		return AE_CTRL_TERMINATE;
+	}
+
+	return AE_OK;
+}
+
+static int riscv_acpi_irq_get_dep(acpi_handle handle, unsigned int index, acpi_handle *gsi_handle)
+{
+	struct acpi_irq_dep_ctx ctx = {-EINVAL, index, NULL};
+
+	if (!gsi_handle)
+		return 0;
+
+	acpi_walk_resources(handle, METHOD_NAME__CRS, riscv_acpi_irq_get_parent, &ctx);
+	*gsi_handle = ctx.handle;
+	if (*gsi_handle)
+		return 1;
+
+	return 0;
+}
+
+static u32 riscv_acpi_add_prt_dep(acpi_handle handle)
+{
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	struct acpi_pci_routing_table *entry;
+	struct acpi_handle_list dep_devices;
+	acpi_handle gsi_handle;
+	acpi_handle link_handle;
+	acpi_status status;
+	u32 count = 0;
+
+	status = acpi_get_irq_routing_table(handle, &buffer);
+	if (ACPI_FAILURE(status)) {
+		acpi_handle_err(handle, "failed to get IRQ routing table\n");
+		kfree(buffer.pointer);
+		return 0;
+	}
+
+	entry = buffer.pointer;
+	while (entry && (entry->length > 0)) {
+		if (entry->source[0]) {
+			acpi_get_handle(handle, entry->source, &link_handle);
+			dep_devices.count = 1;
+			dep_devices.handles = kzalloc_objs(*dep_devices.handles,
+							   1);
+			if (!dep_devices.handles) {
+				acpi_handle_err(handle, "failed to allocate memory\n");
+				continue;
+			}
+
+			dep_devices.handles[0] = link_handle;
+			count += acpi_scan_add_dep(handle, &dep_devices);
+		} else {
+			gsi_handle = riscv_acpi_get_gsi_handle(entry->source_index);
+			dep_devices.count = 1;
+			dep_devices.handles = kzalloc_objs(*dep_devices.handles,
+							   1);
+			if (!dep_devices.handles) {
+				acpi_handle_err(handle, "failed to allocate memory\n");
+				continue;
+			}
+
+			dep_devices.handles[0] = gsi_handle;
+			count += acpi_scan_add_dep(handle, &dep_devices);
+		}
+
+		entry = (struct acpi_pci_routing_table *)
+			((unsigned long)entry + entry->length);
+	}
+
+	kfree(buffer.pointer);
+	return count;
+}
+
+static u32 riscv_acpi_add_irq_dep(acpi_handle handle)
+{
+	struct acpi_handle_list dep_devices;
+	acpi_handle gsi_handle;
+	u32 count = 0;
+	int i;
+
+	for (i = 0;
+	     riscv_acpi_irq_get_dep(handle, i, &gsi_handle);
+	     i++) {
+		dep_devices.count = 1;
+		dep_devices.handles = kzalloc_objs(*dep_devices.handles, 1);
+		if (!dep_devices.handles) {
+			acpi_handle_err(handle, "failed to allocate memory\n");
+			continue;
+		}
+
+		dep_devices.handles[0] = gsi_handle;
+		count += acpi_scan_add_dep(handle, &dep_devices);
+	}
+
+	return count;
+}
+
+u32 arch_acpi_add_auto_dep(acpi_handle handle)
+{
+	if (acpi_has_method(handle, "_PRT"))
+		return riscv_acpi_add_prt_dep(handle);
+
+	return riscv_acpi_add_irq_dep(handle);
+}

linux-7.2.3/drivers/acpi/riscv/rhct.c

@@ -0,0 +1,175 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2022-2023, Ventana Micro Systems Inc
+ *	Author: Sunil V L <sunilvl@ventanamicro.com>
+ *
+ */
+
+#define pr_fmt(fmt)     "ACPI: RHCT: " fmt
+
+#include <linux/acpi.h>
+#include <linux/bits.h>
+
+static struct acpi_table_rhct *acpi_get_rhct(void)
+{
+	static struct acpi_table_header *rhct;
+	acpi_status status;
+
+	/*
+	 * RHCT will be used at runtime on every CPU, so we
+	 * don't need to call acpi_put_table() to release the table mapping.
+	 */
+	if (!rhct) {
+		status = acpi_get_table(ACPI_SIG_RHCT, 0, &rhct);
+		if (ACPI_FAILURE(status)) {
+			pr_warn_once("No RHCT table found\n");
+			return NULL;
+		}
+	}
+
+	return (struct acpi_table_rhct *)rhct;
+}
+
+/*
+ * During early boot, the caller should call acpi_get_table() and pass its pointer to
+ * these functions(and free up later). At run time, since this table can be used
+ * multiple times, NULL may be passed in order to use the cached table.
+ */
+int acpi_get_riscv_isa(struct acpi_table_header *table, unsigned int cpu, const char **isa)
+{
+	struct acpi_rhct_node_header *node, *ref_node, *end;
+	u32 size_hdr = sizeof(struct acpi_rhct_node_header);
+	u32 size_hartinfo = sizeof(struct acpi_rhct_hart_info);
+	struct acpi_rhct_hart_info *hart_info;
+	struct acpi_rhct_isa_string *isa_node;
+	struct acpi_table_rhct *rhct;
+	u32 *hart_info_node_offset;
+	u32 acpi_cpu_id;
+	int ret;
+
+	BUG_ON(acpi_disabled);
+
+	ret = acpi_get_cpu_uid(cpu, &acpi_cpu_id);
+	if (ret != 0)
+		return ret;
+
+	if (!table) {
+		rhct = acpi_get_rhct();
+		if (!rhct)
+			return -ENOENT;
+	} else {
+		rhct = (struct acpi_table_rhct *)table;
+	}
+
+	end = ACPI_ADD_PTR(struct acpi_rhct_node_header, rhct, rhct->header.length);
+
+	for (node = ACPI_ADD_PTR(struct acpi_rhct_node_header, rhct, rhct->node_offset);
+	     node < end;
+	     node = ACPI_ADD_PTR(struct acpi_rhct_node_header, node, node->length)) {
+		if (node->type == ACPI_RHCT_NODE_TYPE_HART_INFO) {
+			hart_info = ACPI_ADD_PTR(struct acpi_rhct_hart_info, node, size_hdr);
+			hart_info_node_offset = ACPI_ADD_PTR(u32, hart_info, size_hartinfo);
+			if (acpi_cpu_id != hart_info->uid)
+				continue;
+
+			for (int i = 0; i < hart_info->num_offsets; i++) {
+				ref_node = ACPI_ADD_PTR(struct acpi_rhct_node_header,
+							rhct, hart_info_node_offset[i]);
+				if (ref_node->type == ACPI_RHCT_NODE_TYPE_ISA_STRING) {
+					isa_node = ACPI_ADD_PTR(struct acpi_rhct_isa_string,
+								ref_node, size_hdr);
+					*isa = isa_node->isa;
+					return 0;
+				}
+			}
+		}
+	}
+
+	return -1;
+}
+
+static void acpi_parse_hart_info_cmo_node(struct acpi_table_rhct *rhct,
+					  struct acpi_rhct_hart_info *hart_info,
+					  u32 *cbom_size, u32 *cboz_size, u32 *cbop_size)
+{
+	u32 size_hartinfo = sizeof(struct acpi_rhct_hart_info);
+	u32 size_hdr = sizeof(struct acpi_rhct_node_header);
+	struct acpi_rhct_node_header *ref_node;
+	struct acpi_rhct_cmo_node *cmo_node;
+	u32 *hart_info_node_offset;
+
+	hart_info_node_offset = ACPI_ADD_PTR(u32, hart_info, size_hartinfo);
+	for (int i = 0; i < hart_info->num_offsets; i++) {
+		ref_node = ACPI_ADD_PTR(struct acpi_rhct_node_header,
+					rhct, hart_info_node_offset[i]);
+		if (ref_node->type == ACPI_RHCT_NODE_TYPE_CMO) {
+			cmo_node = ACPI_ADD_PTR(struct acpi_rhct_cmo_node,
+						ref_node, size_hdr);
+			if (cbom_size && cmo_node->cbom_size <= 30) {
+				if (!*cbom_size)
+					*cbom_size = BIT(cmo_node->cbom_size);
+				else if (*cbom_size != BIT(cmo_node->cbom_size))
+					pr_warn("CBOM size is not the same across harts\n");
+			}
+
+			if (cboz_size && cmo_node->cboz_size <= 30) {
+				if (!*cboz_size)
+					*cboz_size = BIT(cmo_node->cboz_size);
+				else if (*cboz_size != BIT(cmo_node->cboz_size))
+					pr_warn("CBOZ size is not the same across harts\n");
+			}
+
+			if (cbop_size && cmo_node->cbop_size <= 30) {
+				if (!*cbop_size)
+					*cbop_size = BIT(cmo_node->cbop_size);
+				else if (*cbop_size != BIT(cmo_node->cbop_size))
+					pr_warn("CBOP size is not the same across harts\n");
+			}
+		}
+	}
+}
+
+/*
+ * During early boot, the caller should call acpi_get_table() and pass its pointer to
+ * these functions (and free up later). At run time, since this table can be used
+ * multiple times, pass NULL so that the table remains in memory.
+ */
+void acpi_get_cbo_block_size(struct acpi_table_header *table, u32 *cbom_size,
+			     u32 *cboz_size, u32 *cbop_size)
+{
+	u32 size_hdr = sizeof(struct acpi_rhct_node_header);
+	struct acpi_rhct_node_header *node, *end;
+	struct acpi_rhct_hart_info *hart_info;
+	struct acpi_table_rhct *rhct;
+
+	if (acpi_disabled)
+		return;
+
+	if (table) {
+		rhct = (struct acpi_table_rhct *)table;
+	} else {
+		rhct = acpi_get_rhct();
+		if (!rhct)
+			return;
+	}
+
+	if (cbom_size)
+		*cbom_size = 0;
+
+	if (cboz_size)
+		*cboz_size = 0;
+
+	if (cbop_size)
+		*cbop_size = 0;
+
+	end = ACPI_ADD_PTR(struct acpi_rhct_node_header, rhct, rhct->header.length);
+	for (node = ACPI_ADD_PTR(struct acpi_rhct_node_header, rhct, rhct->node_offset);
+	     node < end;
+	     node = ACPI_ADD_PTR(struct acpi_rhct_node_header, node, node->length)) {
+		if (node->type == ACPI_RHCT_NODE_TYPE_HART_INFO) {
+			hart_info = ACPI_ADD_PTR(struct acpi_rhct_hart_info, node, size_hdr);
+			acpi_parse_hart_info_cmo_node(rhct, hart_info, cbom_size,
+						      cboz_size, cbop_size);
+		}
+	}
+}

linux-7.2.3/drivers/acpi/riscv/rimt.c

@@ -0,0 +1,528 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2024-2025, Ventana Micro Systems Inc
+ *	Author: Sunil V L <sunilvl@ventanamicro.com>
+ *
+ */
+
+#define pr_fmt(fmt)	"ACPI: RIMT: " fmt
+
+#include <linux/acpi.h>
+#include <linux/acpi_rimt.h>
+#include <linux/device/driver.h>
+#include <linux/iommu.h>
+#include <linux/list.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include "init.h"
+
+struct rimt_fwnode {
+	struct list_head list;
+	struct acpi_rimt_node *rimt_node;
+	struct fwnode_handle *fwnode;
+};
+
+static LIST_HEAD(rimt_fwnode_list);
+static DEFINE_SPINLOCK(rimt_fwnode_lock);
+
+#define RIMT_TYPE_MASK(type)	(1 << (type))
+#define RIMT_IOMMU_TYPE		BIT(0)
+
+/* Root pointer to the mapped RIMT table */
+static struct acpi_table_header *rimt_table;
+
+/**
+ * rimt_set_fwnode() - Create rimt_fwnode and use it to register
+ *		       iommu data in the rimt_fwnode_list
+ *
+ * @rimt_node: RIMT table node associated with the IOMMU
+ * @fwnode: fwnode associated with the RIMT node
+ *
+ * Returns: 0 on success
+ *          <0 on failure
+ */
+static int rimt_set_fwnode(struct acpi_rimt_node *rimt_node,
+			   struct fwnode_handle *fwnode)
+{
+	struct rimt_fwnode *np;
+
+	np = kzalloc_obj(*np, GFP_ATOMIC);
+
+	if (WARN_ON(!np))
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&np->list);
+	np->rimt_node = rimt_node;
+	np->fwnode = fwnode;
+
+	spin_lock(&rimt_fwnode_lock);
+	list_add_tail(&np->list, &rimt_fwnode_list);
+	spin_unlock(&rimt_fwnode_lock);
+
+	return 0;
+}
+
+static acpi_status rimt_match_node_callback(struct acpi_rimt_node *node,
+					    void *context)
+{
+	acpi_status status = AE_NOT_FOUND;
+	struct device *dev = context;
+
+	if (node->type == ACPI_RIMT_NODE_TYPE_IOMMU) {
+		struct acpi_rimt_iommu *iommu_node = (struct acpi_rimt_iommu *)&node->node_data;
+
+		if (dev_is_pci(dev)) {
+			struct pci_dev *pdev;
+			u16 bdf;
+
+			pdev = to_pci_dev(dev);
+			bdf = PCI_DEVID(pdev->bus->number, pdev->devfn);
+			if ((pci_domain_nr(pdev->bus) == iommu_node->pcie_segment_number) &&
+			    bdf == iommu_node->pcie_bdf) {
+				status = AE_OK;
+			} else {
+				status = AE_NOT_FOUND;
+			}
+		} else {
+			struct platform_device *pdev = to_platform_device(dev);
+			struct resource *res;
+
+			res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+			if (res && res->start == iommu_node->base_address)
+				status = AE_OK;
+			else
+				status = AE_NOT_FOUND;
+		}
+	} else if (node->type == ACPI_RIMT_NODE_TYPE_PCIE_ROOT_COMPLEX) {
+		struct acpi_rimt_pcie_rc *pci_rc;
+		struct pci_bus *bus;
+
+		bus = to_pci_bus(dev);
+		pci_rc = (struct acpi_rimt_pcie_rc *)node->node_data;
+
+		/*
+		 * It is assumed that PCI segment numbers maps one-to-one
+		 * with root complexes. Each segment number can represent only
+		 * one root complex.
+		 */
+		status = pci_rc->pcie_segment_number == pci_domain_nr(bus) ?
+							AE_OK : AE_NOT_FOUND;
+	} else if (node->type == ACPI_RIMT_NODE_TYPE_PLAT_DEVICE) {
+		struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
+		struct acpi_rimt_platform_device *ncomp;
+		struct device *plat_dev = dev;
+		struct acpi_device *adev;
+
+		/*
+		 * Walk the device tree to find a device with an
+		 * ACPI companion; there is no point in scanning
+		 * RIMT for a device matching a platform device if
+		 * the device does not have an ACPI companion to
+		 * start with.
+		 */
+		do {
+			adev = ACPI_COMPANION(plat_dev);
+			if (adev)
+				break;
+
+			plat_dev = plat_dev->parent;
+		} while (plat_dev);
+
+		if (!adev)
+			return status;
+
+		status = acpi_get_name(adev->handle, ACPI_FULL_PATHNAME, &buf);
+		if (ACPI_FAILURE(status)) {
+			dev_warn(plat_dev, "Can't get device full path name\n");
+			return status;
+		}
+
+		ncomp = (struct acpi_rimt_platform_device *)node->node_data;
+		status = !strcmp(ncomp->device_name, buf.pointer) ?
+							AE_OK : AE_NOT_FOUND;
+		acpi_os_free(buf.pointer);
+	}
+
+	return status;
+}
+
+static struct acpi_rimt_node *rimt_scan_node(enum acpi_rimt_node_type type,
+					     void *context)
+{
+	struct acpi_rimt_node *rimt_node, *rimt_end;
+	struct acpi_table_rimt *rimt;
+	int i;
+
+	if (!rimt_table)
+		return NULL;
+
+	/* Get the first RIMT node */
+	rimt = (struct acpi_table_rimt *)rimt_table;
+	rimt_node = ACPI_ADD_PTR(struct acpi_rimt_node, rimt,
+				 rimt->node_offset);
+	rimt_end = ACPI_ADD_PTR(struct acpi_rimt_node, rimt_table,
+				rimt_table->length);
+
+	for (i = 0; i < rimt->num_nodes; i++) {
+		if (WARN_TAINT(rimt_node >= rimt_end, TAINT_FIRMWARE_WORKAROUND,
+			       "RIMT node pointer overflows, bad table!\n"))
+			return NULL;
+
+		if (rimt_node->type == type &&
+		    ACPI_SUCCESS(rimt_match_node_callback(rimt_node, context)))
+			return rimt_node;
+
+		rimt_node = ACPI_ADD_PTR(struct acpi_rimt_node, rimt_node,
+					 rimt_node->length);
+	}
+
+	return NULL;
+}
+
+/*
+ * RISC-V supports IOMMU as a PCI device or a platform device.
+ * When it is a platform device, there should be a namespace device as
+ * well along with RIMT. To create the link between RIMT information and
+ * the platform device, the IOMMU driver should register itself with the
+ * RIMT module. This is true for PCI based IOMMU as well.
+ */
+int rimt_iommu_register(struct device *dev)
+{
+	struct fwnode_handle *rimt_fwnode;
+	struct acpi_rimt_node *node;
+
+	node = rimt_scan_node(ACPI_RIMT_NODE_TYPE_IOMMU, dev);
+	if (!node) {
+		pr_err("Could not find IOMMU node in RIMT\n");
+		return -ENODEV;
+	}
+
+	if (dev_is_pci(dev)) {
+		rimt_fwnode = acpi_alloc_fwnode_static();
+		if (!rimt_fwnode)
+			return -ENOMEM;
+
+		rimt_fwnode->dev = dev;
+		if (!dev->fwnode)
+			dev->fwnode = rimt_fwnode;
+
+		rimt_set_fwnode(node, rimt_fwnode);
+	} else {
+		rimt_set_fwnode(node, dev->fwnode);
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_IOMMU_API
+
+/**
+ * rimt_get_fwnode() - Retrieve fwnode associated with an RIMT node
+ *
+ * @node: RIMT table node to be looked-up
+ *
+ * Returns: fwnode_handle pointer on success, NULL on failure
+ */
+static struct fwnode_handle *rimt_get_fwnode(struct acpi_rimt_node *node)
+{
+	struct fwnode_handle *fwnode = NULL;
+	struct rimt_fwnode *curr;
+
+	spin_lock(&rimt_fwnode_lock);
+	list_for_each_entry(curr, &rimt_fwnode_list, list) {
+		if (curr->rimt_node == node) {
+			fwnode = curr->fwnode;
+			break;
+		}
+	}
+	spin_unlock(&rimt_fwnode_lock);
+
+	return fwnode;
+}
+
+static bool rimt_pcie_rc_supports_ats(struct acpi_rimt_node *node)
+{
+	struct acpi_rimt_pcie_rc *pci_rc;
+
+	pci_rc = (struct acpi_rimt_pcie_rc *)node->node_data;
+	return pci_rc->flags & ACPI_RIMT_PCIE_ATS_SUPPORTED;
+}
+
+static int rimt_iommu_xlate(struct device *dev, struct acpi_rimt_node *node, u32 deviceid)
+{
+	struct fwnode_handle *rimt_fwnode;
+
+	if (!node)
+		return -ENODEV;
+
+	rimt_fwnode = rimt_get_fwnode(node);
+
+	/*
+	 * The IOMMU drivers may not be probed yet. Defer the IOMMU
+	 * configuration if it's still in initialization stage.
+	 */
+	if (!rimt_fwnode)
+		return driver_deferred_probe_check_state(dev);
+
+	/*
+	 * EPROBE_DEFER ensures IOMMU is probed before the devices that
+	 * depend on them. During shutdown, however, the IOMMU may be removed
+	 * first, leading to issues. To avoid this, a device link is added
+	 * which enforces the correct removal order.
+	 */
+	device_link_add(dev, rimt_fwnode->dev, DL_FLAG_AUTOREMOVE_CONSUMER);
+	return acpi_iommu_fwspec_init(dev, deviceid, rimt_fwnode);
+}
+
+struct rimt_pci_alias_info {
+	struct device *dev;
+	struct acpi_rimt_node *node;
+	const struct iommu_ops *ops;
+};
+
+static int rimt_id_map(struct acpi_rimt_id_mapping *map, u8 type, u32 rid_in, u32 *rid_out)
+{
+	if (rid_in < map->source_id_base ||
+	    (rid_in > map->source_id_base + map->num_ids))
+		return -ENXIO;
+
+	*rid_out = map->dest_id_base + (rid_in - map->source_id_base);
+	return 0;
+}
+
+static struct acpi_rimt_node *rimt_node_get_id(struct acpi_rimt_node *node,
+					       u32 *id_out, int index)
+{
+	struct acpi_rimt_platform_device *plat_node;
+	u32 id_mapping_offset, num_id_mapping;
+	struct acpi_rimt_pcie_rc *pci_node;
+	struct acpi_rimt_id_mapping *map;
+	struct acpi_rimt_node *parent;
+
+	if (node->type == ACPI_RIMT_NODE_TYPE_PCIE_ROOT_COMPLEX) {
+		pci_node = (struct acpi_rimt_pcie_rc *)&node->node_data;
+		id_mapping_offset = pci_node->id_mapping_offset;
+		num_id_mapping = pci_node->num_id_mappings;
+	} else if (node->type == ACPI_RIMT_NODE_TYPE_PLAT_DEVICE) {
+		plat_node = (struct acpi_rimt_platform_device *)&node->node_data;
+		id_mapping_offset = plat_node->id_mapping_offset;
+		num_id_mapping = plat_node->num_id_mappings;
+	} else {
+		return NULL;
+	}
+
+	if (!id_mapping_offset || !num_id_mapping || index >= num_id_mapping)
+		return NULL;
+
+	map = ACPI_ADD_PTR(struct acpi_rimt_id_mapping, node,
+			   id_mapping_offset + index * sizeof(*map));
+
+	/* Firmware bug! */
+	if (!map->dest_offset) {
+		pr_err(FW_BUG "[node %p type %d] ID map has NULL parent reference\n",
+		       node, node->type);
+		return NULL;
+	}
+
+	parent = ACPI_ADD_PTR(struct acpi_rimt_node, rimt_table, map->dest_offset);
+
+	if (node->type == ACPI_RIMT_NODE_TYPE_PLAT_DEVICE ||
+	    node->type == ACPI_RIMT_NODE_TYPE_PCIE_ROOT_COMPLEX) {
+		*id_out = map->dest_id_base;
+		return parent;
+	}
+
+	return NULL;
+}
+
+static struct acpi_rimt_node *rimt_node_map_id(struct acpi_rimt_node *node,
+					       u32 id_in, u32 *id_out,
+					       u8 type_mask)
+{
+	struct acpi_rimt_platform_device *plat_node;
+	u32 id_mapping_offset, num_id_mapping;
+	struct acpi_rimt_pcie_rc *pci_node;
+	u32 id = id_in;
+
+	/* Parse the ID mapping tree to find specified node type */
+	while (node) {
+		struct acpi_rimt_id_mapping *map;
+		int i, rc = 0;
+		u32 map_id = id;
+
+		if (RIMT_TYPE_MASK(node->type) & type_mask) {
+			if (id_out)
+				*id_out = id;
+			return node;
+		}
+
+		if (node->type == ACPI_RIMT_NODE_TYPE_PCIE_ROOT_COMPLEX) {
+			pci_node = (struct acpi_rimt_pcie_rc *)&node->node_data;
+			id_mapping_offset = pci_node->id_mapping_offset;
+			num_id_mapping = pci_node->num_id_mappings;
+		} else if (node->type == ACPI_RIMT_NODE_TYPE_PLAT_DEVICE) {
+			plat_node = (struct acpi_rimt_platform_device *)&node->node_data;
+			id_mapping_offset = plat_node->id_mapping_offset;
+			num_id_mapping = plat_node->num_id_mappings;
+		} else {
+			goto fail_map;
+		}
+
+		if (!id_mapping_offset || !num_id_mapping)
+			goto fail_map;
+
+		map = ACPI_ADD_PTR(struct acpi_rimt_id_mapping, node,
+				   id_mapping_offset);
+
+		/* Firmware bug! */
+		if (!map->dest_offset) {
+			pr_err(FW_BUG "[node %p type %d] ID map has NULL parent reference\n",
+			       node, node->type);
+			goto fail_map;
+		}
+
+		/* Do the ID translation */
+		for (i = 0; i < num_id_mapping; i++, map++) {
+			rc = rimt_id_map(map, node->type, map_id, &id);
+			if (!rc)
+				break;
+		}
+
+		if (i == num_id_mapping)
+			goto fail_map;
+
+		node = ACPI_ADD_PTR(struct acpi_rimt_node, rimt_table,
+				    rc ? 0 : map->dest_offset);
+	}
+
+fail_map:
+	/* Map input ID to output ID unchanged on mapping failure */
+	if (id_out)
+		*id_out = id_in;
+
+	return NULL;
+}
+
+static struct acpi_rimt_node *rimt_node_map_platform_id(struct acpi_rimt_node *node, u32 *id_out,
+							u8 type_mask, int index)
+{
+	struct acpi_rimt_node *parent;
+	u32 id;
+
+	parent = rimt_node_get_id(node, &id, index);
+	if (!parent)
+		return NULL;
+
+	if (!(RIMT_TYPE_MASK(parent->type) & type_mask))
+		parent = rimt_node_map_id(parent, id, id_out, type_mask);
+	else
+		if (id_out)
+			*id_out = id;
+
+	return parent;
+}
+
+static int rimt_pci_iommu_init(struct pci_dev *pdev, u16 alias, void *data)
+{
+	struct rimt_pci_alias_info *info = data;
+	struct acpi_rimt_node *parent;
+	u32 deviceid;
+
+	parent = rimt_node_map_id(info->node, alias, &deviceid, RIMT_IOMMU_TYPE);
+	return rimt_iommu_xlate(info->dev, parent, deviceid);
+}
+
+static int rimt_plat_iommu_map(struct device *dev, struct acpi_rimt_node *node)
+{
+	struct acpi_rimt_node *parent;
+	int err = -ENODEV, i = 0;
+	u32 deviceid = 0;
+
+	do {
+		parent = rimt_node_map_platform_id(node, &deviceid,
+						   RIMT_IOMMU_TYPE,
+						   i++);
+
+		if (parent)
+			err = rimt_iommu_xlate(dev, parent, deviceid);
+	} while (parent && !err);
+
+	return err;
+}
+
+static int rimt_plat_iommu_map_id(struct device *dev,
+				  struct acpi_rimt_node *node,
+				  const u32 *in_id)
+{
+	struct acpi_rimt_node *parent;
+	u32 deviceid;
+
+	parent = rimt_node_map_id(node, *in_id, &deviceid, RIMT_IOMMU_TYPE);
+	if (parent)
+		return rimt_iommu_xlate(dev, parent, deviceid);
+
+	return -ENODEV;
+}
+
+/**
+ * rimt_iommu_configure_id - Set-up IOMMU configuration for a device.
+ *
+ * @dev: device to configure
+ * @id_in: optional input id const value pointer
+ *
+ * Returns: 0 on success, <0 on failure
+ */
+int rimt_iommu_configure_id(struct device *dev, const u32 *id_in)
+{
+	struct acpi_rimt_node *node;
+	int err = -ENODEV;
+
+	if (dev_is_pci(dev)) {
+		struct iommu_fwspec *fwspec;
+		struct pci_bus *bus = to_pci_dev(dev)->bus;
+		struct rimt_pci_alias_info info = { .dev = dev };
+
+		node = rimt_scan_node(ACPI_RIMT_NODE_TYPE_PCIE_ROOT_COMPLEX, &bus->dev);
+		if (!node)
+			return -ENODEV;
+
+		info.node = node;
+		err = pci_for_each_dma_alias(to_pci_dev(dev),
+					     rimt_pci_iommu_init, &info);
+
+		fwspec = dev_iommu_fwspec_get(dev);
+		if (fwspec && rimt_pcie_rc_supports_ats(node))
+			fwspec->flags |= IOMMU_FWSPEC_PCI_RC_ATS;
+	} else {
+		node = rimt_scan_node(ACPI_RIMT_NODE_TYPE_PLAT_DEVICE, dev);
+		if (!node)
+			return -ENODEV;
+
+		err = id_in ? rimt_plat_iommu_map_id(dev, node, id_in) :
+			      rimt_plat_iommu_map(dev, node);
+	}
+
+	return err;
+}
+
+#endif
+
+void __init riscv_acpi_rimt_init(void)
+{
+	acpi_status status;
+
+	/* rimt_table will be used at runtime after the rimt init,
+	 * so we don't need to call acpi_put_table() to release
+	 * the RIMT table mapping.
+	 */
+	status = acpi_get_table(ACPI_SIG_RIMT, 0, &rimt_table);
+	if (ACPI_FAILURE(status)) {
+		if (status != AE_NOT_FOUND) {
+			const char *msg = acpi_format_exception(status);
+
+			pr_err("Failed to get table, %s\n", msg);
+		}
+
+		return;
+	}
+}