1 files changed, 255 insertions, 26 deletions

diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
index 3a58e9db5cfe..dba8fcec7f33 100644
--- a/arch/arm64/kernel/acpi.c
+++ b/arch/arm64/kernel/acpi.c
@@ -13,22 +13,25 @@
 #define pr_fmt(fmt) "ACPI: " fmt
 
 #include <linux/acpi.h>
+#include <linux/arm-smccc.h>
 #include <linux/cpumask.h>
 #include <linux/efi.h>
 #include <linux/efi-bgrt.h>
 #include <linux/init.h>
 #include <linux/irq.h>
 #include <linux/irqdomain.h>
+#include <linux/irq_work.h>
 #include <linux/memblock.h>
 #include <linux/of_fdt.h>
+#include <linux/libfdt.h>
 #include <linux/smp.h>
 #include <linux/serial_core.h>
+#include <linux/pgtable.h>
 
 #include <acpi/ghes.h>
 #include <asm/cputype.h>
 #include <asm/cpu_ops.h>
 #include <asm/daifflags.h>
-#include <asm/pgtable.h>
 #include <asm/smp_plat.h>
 
 int acpi_noirq = 1;		/* skip ACPI IRQ initialization */
@@ -61,29 +64,22 @@ static int __init parse_acpi(char *arg)
 }
 early_param("acpi", parse_acpi);
 
-static int __init dt_scan_depth1_nodes(unsigned long node,
-				       const char *uname, int depth,
-				       void *data)
+static bool __init dt_is_stub(void)
 {
-	/*
-	 * Ignore anything not directly under the root node; we'll
-	 * catch its parent instead.
-	 */
-	if (depth != 1)
-		return 0;
+	int node;
 
-	if (strcmp(uname, "chosen") == 0)
-		return 0;
+	fdt_for_each_subnode(node, initial_boot_params, 0) {
+		const char *name = fdt_get_name(initial_boot_params, node, NULL);
+		if (strcmp(name, "chosen") == 0)
+			continue;
+		if (strcmp(name, "hypervisor") == 0 &&
+		    of_flat_dt_is_compatible(node, "xen,xen"))
+			continue;
 
-	if (strcmp(uname, "hypervisor") == 0 &&
-	    of_flat_dt_is_compatible(node, "xen,xen"))
-		return 0;
+		return false;
+	}
 
-	/*
-	 * This node at depth 1 is neither a chosen node nor a xen node,
-	 * which we do not expect.
-	 */
-	return 1;
+	return true;
 }
 
 /*
@@ -204,8 +200,7 @@ void __init acpi_boot_table_init(void)
 	 *   and ACPI has not been [force] enabled (acpi=on|force)
 	 */
 	if (param_acpi_off ||
-	    (!param_acpi_on && !param_acpi_force &&
-	     of_scan_flat_dt(dt_scan_depth1_nodes, NULL)))
+	    (!param_acpi_on && !param_acpi_force && !dt_is_stub()))
 		goto done;
 
 	/*
@@ -238,6 +233,18 @@ done:
 	}
 }
 
+static pgprot_t __acpi_get_writethrough_mem_attribute(void)
+{
+	/*
+	 * Although UEFI specifies the use of Normal Write-through for
+	 * EFI_MEMORY_WT, it is seldom used in practice and not implemented
+	 * by most (all?) CPUs. Rather than allocate a MAIR just for this
+	 * purpose, emit a warning and use Normal Non-cacheable instead.
+	 */
+	pr_warn_once("No MAIR allocation for EFI_MEMORY_WT; treating as Normal Non-cacheable\n");
+	return __pgprot(PROT_NORMAL_NC);
+}
+
 pgprot_t __acpi_get_mem_attribute(phys_addr_t addr)
 {
 	/*
@@ -245,7 +252,7 @@ pgprot_t __acpi_get_mem_attribute(phys_addr_t addr)
 	 * types" of UEFI 2.5 section 2.3.6.1, each EFI memory type is
 	 * mapped to a corresponding MAIR attribute encoding.
 	 * The EFI memory attribute advises all possible capabilities
-	 * of a memory region. We use the most efficient capability.
+	 * of a memory region.
 	 */
 
 	u64 attr;
@@ -253,13 +260,101 @@ pgprot_t __acpi_get_mem_attribute(phys_addr_t addr)
 	attr = efi_mem_attributes(addr);
 	if (attr & EFI_MEMORY_WB)
 		return PAGE_KERNEL;
-	if (attr & EFI_MEMORY_WT)
-		return __pgprot(PROT_NORMAL_WT);
 	if (attr & EFI_MEMORY_WC)
 		return __pgprot(PROT_NORMAL_NC);
+	if (attr & EFI_MEMORY_WT)
+		return __acpi_get_writethrough_mem_attribute();
 	return __pgprot(PROT_DEVICE_nGnRnE);
 }
 
+void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size)
+{
+	efi_memory_desc_t *md, *region = NULL;
+	pgprot_t prot;
+
+	if (WARN_ON_ONCE(!efi_enabled(EFI_MEMMAP)))
+		return NULL;
+
+	for_each_efi_memory_desc(md) {
+		u64 end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT);
+
+		if (phys < md->phys_addr || phys >= end)
+			continue;
+
+		if (phys + size > end) {
+			pr_warn(FW_BUG "requested region covers multiple EFI memory regions\n");
+			return NULL;
+		}
+		region = md;
+		break;
+	}
+
+	/*
+	 * It is fine for AML to remap regions that are not represented in the
+	 * EFI memory map at all, as it only describes normal memory, and MMIO
+	 * regions that require a virtual mapping to make them accessible to
+	 * the EFI runtime services.
+	 */
+	prot = __pgprot(PROT_DEVICE_nGnRnE);
+	if (region) {
+		switch (region->type) {
+		case EFI_LOADER_CODE:
+		case EFI_LOADER_DATA:
+		case EFI_BOOT_SERVICES_CODE:
+		case EFI_BOOT_SERVICES_DATA:
+		case EFI_CONVENTIONAL_MEMORY:
+		case EFI_PERSISTENT_MEMORY:
+			if (memblock_is_map_memory(phys) ||
+			    !memblock_is_region_memory(phys, size)) {
+				pr_warn(FW_BUG "requested region covers kernel memory @ %pa\n", &phys);
+				return NULL;
+			}
+			/*
+			 * Mapping kernel memory is permitted if the region in
+			 * question is covered by a single memblock with the
+			 * NOMAP attribute set: this enables the use of ACPI
+			 * table overrides passed via initramfs, which are
+			 * reserved in memory using arch_reserve_mem_area()
+			 * below. As this particular use case only requires
+			 * read access, fall through to the R/O mapping case.
+			 */
+			fallthrough;
+
+		case EFI_RUNTIME_SERVICES_CODE:
+			/*
+			 * This would be unusual, but not problematic per se,
+			 * as long as we take care not to create a writable
+			 * mapping for executable code.
+			 */
+			prot = PAGE_KERNEL_RO;
+			break;
+
+		case EFI_ACPI_RECLAIM_MEMORY:
+			/*
+			 * ACPI reclaim memory is used to pass firmware tables
+			 * and other data that is intended for consumption by
+			 * the OS only, which may decide it wants to reclaim
+			 * that memory and use it for something else. We never
+			 * do that, but we usually add it to the linear map
+			 * anyway, in which case we should use the existing
+			 * mapping.
+			 */
+			if (memblock_is_map_memory(phys))
+				return (void __iomem *)__phys_to_virt(phys);
+			fallthrough;
+
+		default:
+			if (region->attribute & EFI_MEMORY_WB)
+				prot = PAGE_KERNEL;
+			else if (region->attribute & EFI_MEMORY_WC)
+				prot = __pgprot(PROT_NORMAL_NC);
+			else if (region->attribute & EFI_MEMORY_WT)
+				prot = __acpi_get_writethrough_mem_attribute();
+		}
+	}
+	return ioremap_prot(phys, size, pgprot_val(prot));
+}
+
 /*
  * Claim Synchronous External Aborts as a firmware first notification.
  *
@@ -269,12 +364,19 @@ pgprot_t __acpi_get_mem_attribute(phys_addr_t addr)
 int apei_claim_sea(struct pt_regs *regs)
 {
 	int err = -ENOENT;
+	bool return_to_irqs_enabled;
 	unsigned long current_flags;
 
 	if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES))
 		return err;
 
-	current_flags = arch_local_save_flags();
+	current_flags = local_daif_save_flags();
+
+	/* current_flags isn't useful here as daif doesn't tell us about pNMI */
+	return_to_irqs_enabled = !irqs_disabled_flags(arch_local_save_flags());
+
+	if (regs)
+		return_to_irqs_enabled = interrupts_enabled(regs);
 
 	/*
 	 * SEA can interrupt SError, mask it and describe this as an NMI so
@@ -284,7 +386,134 @@ int apei_claim_sea(struct pt_regs *regs)
 	nmi_enter();
 	err = ghes_notify_sea();
 	nmi_exit();
+
+	/*
+	 * APEI NMI-like notifications are deferred to irq_work. Unless
+	 * we interrupted irqs-masked code, we can do that now.
+	 */
+	if (!err) {
+		if (return_to_irqs_enabled) {
+			local_daif_restore(DAIF_PROCCTX_NOIRQ);
+			__irq_enter();
+			irq_work_run();
+			__irq_exit();
+		} else {
+			pr_warn_ratelimited("APEI work queued but not completed");
+			err = -EINPROGRESS;
+		}
+	}
+
 	local_daif_restore(current_flags);
 
 	return err;
 }
+
+void arch_reserve_mem_area(acpi_physical_address addr, size_t size)
+{
+	memblock_mark_nomap(addr, size);
+}
+
+#ifdef CONFIG_ACPI_FFH
+/*
+ * Implements ARM64 specific callbacks to support ACPI FFH Operation Region as
+ * specified in https://developer.arm.com/docs/den0048/latest
+ */
+struct acpi_ffh_data {
+	struct acpi_ffh_info info;
+	void (*invoke_ffh_fn)(unsigned long a0, unsigned long a1,
+			      unsigned long a2, unsigned long a3,
+			      unsigned long a4, unsigned long a5,
+			      unsigned long a6, unsigned long a7,
+			      struct arm_smccc_res *args,
+			      struct arm_smccc_quirk *res);
+	void (*invoke_ffh64_fn)(const struct arm_smccc_1_2_regs *args,
+				struct arm_smccc_1_2_regs *res);
+};
+
+int acpi_ffh_address_space_arch_setup(void *handler_ctxt, void **region_ctxt)
+{
+	enum arm_smccc_conduit conduit;
+	struct acpi_ffh_data *ffh_ctxt;
+
+	if (arm_smccc_get_version() < ARM_SMCCC_VERSION_1_2)
+		return -EOPNOTSUPP;
+
+	conduit = arm_smccc_1_1_get_conduit();
+	if (conduit == SMCCC_CONDUIT_NONE) {
+		pr_err("%s: invalid SMCCC conduit\n", __func__);
+		return -EOPNOTSUPP;
+	}
+
+	ffh_ctxt = kzalloc(sizeof(*ffh_ctxt), GFP_KERNEL);
+	if (!ffh_ctxt)
+		return -ENOMEM;
+
+	if (conduit == SMCCC_CONDUIT_SMC) {
+		ffh_ctxt->invoke_ffh_fn = __arm_smccc_smc;
+		ffh_ctxt->invoke_ffh64_fn = arm_smccc_1_2_smc;
+	} else {
+		ffh_ctxt->invoke_ffh_fn = __arm_smccc_hvc;
+		ffh_ctxt->invoke_ffh64_fn = arm_smccc_1_2_hvc;
+	}
+
+	memcpy(ffh_ctxt, handler_ctxt, sizeof(ffh_ctxt->info));
+
+	*region_ctxt = ffh_ctxt;
+	return AE_OK;
+}
+
+static bool acpi_ffh_smccc_owner_allowed(u32 fid)
+{
+	int owner = ARM_SMCCC_OWNER_NUM(fid);
+
+	if (owner == ARM_SMCCC_OWNER_STANDARD ||
+	    owner == ARM_SMCCC_OWNER_SIP || owner == ARM_SMCCC_OWNER_OEM)
+		return true;
+
+	return false;
+}
+
+int acpi_ffh_address_space_arch_handler(acpi_integer *value, void *region_context)
+{
+	int ret = 0;
+	struct acpi_ffh_data *ffh_ctxt = region_context;
+
+	if (ffh_ctxt->info.offset == 0) {
+		/* SMC/HVC 32bit call */
+		struct arm_smccc_res res;
+		u32 a[8] = { 0 }, *ptr = (u32 *)value;
+
+		if (!ARM_SMCCC_IS_FAST_CALL(*ptr) || ARM_SMCCC_IS_64(*ptr) ||
+		    !acpi_ffh_smccc_owner_allowed(*ptr) ||
+		    ffh_ctxt->info.length > 32) {
+			ret = AE_ERROR;
+		} else {
+			int idx, len = ffh_ctxt->info.length >> 2;
+
+			for (idx = 0; idx < len; idx++)
+				a[idx] = *(ptr + idx);
+
+			ffh_ctxt->invoke_ffh_fn(a[0], a[1], a[2], a[3], a[4],
+						a[5], a[6], a[7], &res, NULL);
+			memcpy(value, &res, sizeof(res));
+		}
+
+	} else if (ffh_ctxt->info.offset == 1) {
+		/* SMC/HVC 64bit call */
+		struct arm_smccc_1_2_regs *r = (struct arm_smccc_1_2_regs *)value;
+
+		if (!ARM_SMCCC_IS_FAST_CALL(r->a0) || !ARM_SMCCC_IS_64(r->a0) ||
+		    !acpi_ffh_smccc_owner_allowed(r->a0) ||
+		    ffh_ctxt->info.length > sizeof(*r)) {
+			ret = AE_ERROR;
+		} else {
+			ffh_ctxt->invoke_ffh64_fn(r, r);
+			memcpy(value, r, ffh_ctxt->info.length);
+		}
+	} else {
+		ret = AE_ERROR;
+	}
+
+	return ret;
+}
+#endif /* CONFIG_ACPI_FFH */