@@ -47,6 +47,13 @@ config EFI_RUNTIME_MAP
See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map.
+config UEFI_PARAMS_FROM_FDT
+ bool
+ help
+ Select this config option from the architecture Kconfig if
+ the EFI runtime support gets system table address, memory
+ map address, and other parameters from the device tree.
+
endmenu
config UEFI_CPER
@@ -20,6 +20,8 @@
#include <linux/init.h>
#include <linux/device.h>
#include <linux/efi.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
#include <linux/io.h>
struct efi __read_mostly efi = {
@@ -318,3 +320,80 @@ int __init efi_config_init(efi_config_table_type_t *arch_tables)
return 0;
}
+
+#ifdef CONFIG_UEFI_PARAMS_FROM_FDT
+
+#define UEFI_PARAM(name, prop, field) \
+ { \
+ { name }, \
+ { prop }, \
+ offsetof(struct efi_fdt_params, field), \
+ FIELD_SIZEOF(struct efi_fdt_params, field) \
+ }
+
+static __initdata struct {
+ const char name[32];
+ const char propname[32];
+ int offset;
+ int size;
+} dt_params[] = {
+ UEFI_PARAM("System Table", "linux,uefi-system-table", system_table),
+ UEFI_PARAM("MemMap Address", "linux,uefi-mmap-start", mmap),
+ UEFI_PARAM("MemMap Size", "linux,uefi-mmap-size", mmap_size),
+ UEFI_PARAM("MemMap Desc. Size", "linux,uefi-mmap-desc-size", desc_size),
+ UEFI_PARAM("MemMap Desc. Version", "linux,uefi-mmap-desc-ver", desc_ver)
+};
+
+struct param_info {
+ int verbose;
+ void *params;
+};
+
+static int __init fdt_find_uefi_params(unsigned long node, const char *uname,
+ int depth, void *data)
+{
+ struct param_info *info = data;
+ void *prop, *dest;
+ unsigned long len;
+ u64 val;
+ int i;
+
+ if (depth != 1 ||
+ (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
+ return 0;
+
+ pr_info("Getting parameters from FDT:\n");
+
+ for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
+ prop = of_get_flat_dt_prop(node, dt_params[i].propname, &len);
+ if (!prop) {
+ pr_err("Can't find %s in device tree!\n",
+ dt_params[i].name);
+ return 0;
+ }
+ dest = info->params + dt_params[i].offset;
+
+ val = of_read_number(prop, len / sizeof(u32));
+
+ if (dt_params[i].size == sizeof(u32))
+ *(u32 *)dest = val;
+ else
+ *(u64 *)dest = val;
+
+ if (info->verbose)
+ pr_info(" %s: 0x%0*llx\n", dt_params[i].name,
+ dt_params[i].size * 2, val);
+ }
+ return 1;
+}
+
+int __init efi_get_fdt_params(struct efi_fdt_params *params, int verbose)
+{
+ struct param_info info;
+
+ info.verbose = verbose;
+ info.params = params;
+
+ return of_scan_flat_dt(fdt_find_uefi_params, &info);
+}
+#endif /* CONFIG_UEFI_PARAMS_FROM_FDT */
@@ -483,6 +483,14 @@ struct efi_memory_map {
unsigned long desc_size;
};
+struct efi_fdt_params {
+ u64 system_table;
+ u64 mmap;
+ u32 mmap_size;
+ u32 desc_size;
+ u32 desc_ver;
+};
+
typedef struct {
u32 revision;
void *parent_handle;
@@ -620,6 +628,7 @@ extern void efi_initialize_iomem_resources(struct resource *code_resource,
extern void efi_get_time(struct timespec *now);
extern int efi_set_rtc_mmss(const struct timespec *now);
extern void efi_reserve_boot_services(void);
+extern int efi_get_fdt_params(struct efi_fdt_params *params, int verbose);
extern struct efi_memory_map memmap;
/* Iterate through an efi_memory_map */