4 files changed, 167 insertions, 52 deletions

diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 05509f3aaee8..8730fd475bf3 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -24,6 +24,9 @@
 #include <linux/of_fdt.h>
 #include <linux/io.h>
 #include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/acpi.h>
+#include <linux/ucs2_string.h>
 
 #include <asm/early_ioremap.h>
 
@@ -195,6 +198,96 @@ static void generic_ops_unregister(void)
 	efivars_unregister(&generic_efivars);
 }
 
+#if IS_ENABLED(CONFIG_ACPI)
+#define EFIVAR_SSDT_NAME_MAX	16
+static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata;
+static int __init efivar_ssdt_setup(char *str)
+{
+	if (strlen(str) < sizeof(efivar_ssdt))
+		memcpy(efivar_ssdt, str, strlen(str));
+	else
+		pr_warn("efivar_ssdt: name too long: %s\n", str);
+	return 0;
+}
+__setup("efivar_ssdt=", efivar_ssdt_setup);
+
+static __init int efivar_ssdt_iter(efi_char16_t *name, efi_guid_t vendor,
+				   unsigned long name_size, void *data)
+{
+	struct efivar_entry *entry;
+	struct list_head *list = data;
+	char utf8_name[EFIVAR_SSDT_NAME_MAX];
+	int limit = min_t(unsigned long, EFIVAR_SSDT_NAME_MAX, name_size);
+
+	ucs2_as_utf8(utf8_name, name, limit - 1);
+	if (strncmp(utf8_name, efivar_ssdt, limit) != 0)
+		return 0;
+
+	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
+	if (!entry)
+		return 0;
+
+	memcpy(entry->var.VariableName, name, name_size);
+	memcpy(&entry->var.VendorGuid, &vendor, sizeof(efi_guid_t));
+
+	efivar_entry_add(entry, list);
+
+	return 0;
+}
+
+static __init int efivar_ssdt_load(void)
+{
+	LIST_HEAD(entries);
+	struct efivar_entry *entry, *aux;
+	unsigned long size;
+	void *data;
+	int ret;
+
+	ret = efivar_init(efivar_ssdt_iter, &entries, true, &entries);
+
+	list_for_each_entry_safe(entry, aux, &entries, list) {
+		pr_info("loading SSDT from variable %s-%pUl\n", efivar_ssdt,
+			&entry->var.VendorGuid);
+
+		list_del(&entry->list);
+
+		ret = efivar_entry_size(entry, &size);
+		if (ret) {
+			pr_err("failed to get var size\n");
+			goto free_entry;
+		}
+
+		data = kmalloc(size, GFP_KERNEL);
+		if (!data)
+			goto free_entry;
+
+		ret = efivar_entry_get(entry, NULL, &size, data);
+		if (ret) {
+			pr_err("failed to get var data\n");
+			goto free_data;
+		}
+
+		ret = acpi_load_table(data);
+		if (ret) {
+			pr_err("failed to load table: %d\n", ret);
+			goto free_data;
+		}
+
+		goto free_entry;
+
+free_data:
+		kfree(data);
+
+free_entry:
+		kfree(entry);
+	}
+
+	return ret;
+}
+#else
+static inline int efivar_ssdt_load(void) { return 0; }
+#endif
+
 /*
  * We register the efi subsystem with the firmware subsystem and the
  * efivars subsystem with the efi subsystem, if the system was booted with
@@ -218,6 +311,9 @@ static int __init efisubsys_init(void)
 	if (error)
 		goto err_put;
 
+	if (efi_enabled(EFI_RUNTIME_SERVICES))
+		efivar_ssdt_load();
+
 	error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
 	if (error) {
 		pr_err("efi: Sysfs attribute export failed with error %d.\n",
diff --git a/drivers/firmware/efi/efibc.c b/drivers/firmware/efi/efibc.c
index 8dd0c7085e59..503bbe2a9d49 100644
--- a/drivers/firmware/efi/efibc.c
+++ b/drivers/firmware/efi/efibc.c
@@ -37,13 +37,13 @@ static int efibc_set_variable(const char *name, const char *value)
 	size_t size = (strlen(value) + 1) * sizeof(efi_char16_t);
 
 	if (size > sizeof(entry->var.Data)) {
-		pr_err("value is too large");
+		pr_err("value is too large (%zu bytes) for '%s' EFI variable\n", size, name);
 		return -EINVAL;
 	}
 
 	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
 	if (!entry) {
-		pr_err("failed to allocate efivar entry");
+		pr_err("failed to allocate efivar entry for '%s' EFI variable\n", name);
 		return -ENOMEM;
 	}
 
diff --git a/drivers/firmware/efi/runtime-wrappers.c b/drivers/firmware/efi/runtime-wrappers.c
index 23bef6bb73ee..41958774cde3 100644
--- a/drivers/firmware/efi/runtime-wrappers.c
+++ b/drivers/firmware/efi/runtime-wrappers.c
@@ -22,7 +22,16 @@
 #include <linux/stringify.h>
 #include <asm/efi.h>
 
-static void efi_call_virt_check_flags(unsigned long flags, const char *call)
+/*
+ * Wrap around the new efi_call_virt_generic() macros so that the
+ * code doesn't get too cluttered:
+ */
+#define efi_call_virt(f, args...)   \
+	efi_call_virt_pointer(efi.systab->runtime, f, args)
+#define __efi_call_virt(f, args...) \
+	__efi_call_virt_pointer(efi.systab->runtime, f, args)
+
+void efi_call_virt_check_flags(unsigned long flags, const char *call)
 {
 	unsigned long cur_flags, mismatch;
 
@@ -39,48 +48,6 @@ static void efi_call_virt_check_flags(unsigned long flags, const char *call)
 }
 
 /*
- * Arch code can implement the following three template macros, avoiding
- * reptition for the void/non-void return cases of {__,}efi_call_virt:
- *
- *  * arch_efi_call_virt_setup
- *
- *    Sets up the environment for the call (e.g. switching page tables,
- *    allowing kernel-mode use of floating point, if required).
- *
- *  * arch_efi_call_virt
- *
- *    Performs the call. The last expression in the macro must be the call
- *    itself, allowing the logic to be shared by the void and non-void
- *    cases.
- *
- *  * arch_efi_call_virt_teardown
- *
- *    Restores the usual kernel environment once the call has returned.
- */
-
-#define efi_call_virt(f, args...)					\
-({									\
-	efi_status_t __s;						\
-	unsigned long flags;						\
-	arch_efi_call_virt_setup();					\
-	local_save_flags(flags);					\
-	__s = arch_efi_call_virt(f, args);				\
-	efi_call_virt_check_flags(flags, __stringify(f));		\
-	arch_efi_call_virt_teardown();					\
-	__s;								\
-})
-
-#define __efi_call_virt(f, args...)					\
-({									\
-	unsigned long flags;						\
-	arch_efi_call_virt_setup();					\
-	local_save_flags(flags);					\
-	arch_efi_call_virt(f, args);					\
-	efi_call_virt_check_flags(flags, __stringify(f));		\
-	arch_efi_call_virt_teardown();					\
-})
-
-/*
  * According to section 7.1 of the UEFI spec, Runtime Services are not fully
  * reentrant, and there are particular combinations of calls that need to be
  * serialized. (source: UEFI Specification v2.4A)
diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
index 03e04582791c..8263429e21b8 100644
--- a/drivers/firmware/psci.c
+++ b/drivers/firmware/psci.c
@@ -13,6 +13,7 @@
 
 #define pr_fmt(fmt) "psci: " fmt
 
+#include <linux/acpi.h>
 #include <linux/arm-smccc.h>
 #include <linux/cpuidle.h>
 #include <linux/errno.h>
@@ -256,13 +257,6 @@ static int psci_dt_cpu_init_idle(struct device_node *cpu_node, int cpu)
 	u32 *psci_states;
 	struct device_node *state_node;
 
-	/*
-	 * If the PSCI cpu_suspend function hook has not been initialized
-	 * idle states must not be enabled, so bail out
-	 */
-	if (!psci_ops.cpu_suspend)
-		return -EOPNOTSUPP;
-
 	/* Count idle states */
 	while ((state_node = of_parse_phandle(cpu_node, "cpu-idle-states",
 					      count))) {
@@ -310,11 +304,69 @@ free_mem:
 	return ret;
 }
 
+#ifdef CONFIG_ACPI
+#include <acpi/processor.h>
+
+static int __maybe_unused psci_acpi_cpu_init_idle(unsigned int cpu)
+{
+	int i, count;
+	u32 *psci_states;
+	struct acpi_lpi_state *lpi;
+	struct acpi_processor *pr = per_cpu(processors, cpu);
+
+	if (unlikely(!pr || !pr->flags.has_lpi))
+		return -EINVAL;
+
+	count = pr->power.count - 1;
+	if (count <= 0)
+		return -ENODEV;
+
+	psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL);
+	if (!psci_states)
+		return -ENOMEM;
+
+	for (i = 0; i < count; i++) {
+		u32 state;
+
+		lpi = &pr->power.lpi_states[i + 1];
+		/*
+		 * Only bits[31:0] represent a PSCI power_state while
+		 * bits[63:32] must be 0x0 as per ARM ACPI FFH Specification
+		 */
+		state = lpi->address;
+		if (!psci_power_state_is_valid(state)) {
+			pr_warn("Invalid PSCI power state %#x\n", state);
+			kfree(psci_states);
+			return -EINVAL;
+		}
+		psci_states[i] = state;
+	}
+	/* Idle states parsed correctly, initialize per-cpu pointer */
+	per_cpu(psci_power_state, cpu) = psci_states;
+	return 0;
+}
+#else
+static int __maybe_unused psci_acpi_cpu_init_idle(unsigned int cpu)
+{
+	return -EINVAL;
+}
+#endif
+
 int psci_cpu_init_idle(unsigned int cpu)
 {
 	struct device_node *cpu_node;
 	int ret;
 
+	/*
+	 * If the PSCI cpu_suspend function hook has not been initialized
+	 * idle states must not be enabled, so bail out
+	 */
+	if (!psci_ops.cpu_suspend)
+		return -EOPNOTSUPP;
+
+	if (!acpi_disabled)
+		return psci_acpi_cpu_init_idle(cpu);
+
 	cpu_node = of_get_cpu_node(cpu, NULL);
 	if (!cpu_node)
 		return -ENODEV;