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authorMark Salter <msalter@redhat.com>2013-12-30 12:12:12 -0500
committerMark Brown <broonie@linaro.org>2014-06-16 21:35:23 +0100
commit37d133e5122b80b5a13b2658b15baf695d3fda19 (patch)
tree0dc6db6442029c57ec8b85936b6e04a03f63243f
parent8ef5a88c0bdda0b47913f82a1fc6f28e481a486d (diff)
downloadlinux-linaro-stable-37d133e5122b80b5a13b2658b15baf695d3fda19.tar.gz
efi: add helper function to get UEFI params from FDT
ARM and ARM64 architectures use the device tree to pass UEFI parameters from stub to kernel. These parameters are things known to the stub but not discoverable by the kernel after the stub calls ExitBootSerives(). There is a helper function in: drivers/firmware/efi/fdt.c which the stub uses to add the UEFI parameters to the device tree. This patch adds a complimentary helper function which UEFI runtime support may use to retrieve the parameters from the device tree. If an architecture wants to use this helper, it should select CONFIG_EFI_PARAMS_FROM_FDT. Signed-off-by: Mark Salter <msalter@redhat.com> Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com> (cherry picked from commit 0302f71c0aa59571ac306f93068fbbfe65ea349b) Signed-off-by: Mark Brown <broonie@linaro.org> Conflicts: drivers/firmware/efi/Kconfig
-rw-r--r--drivers/firmware/efi/Kconfig7
-rw-r--r--drivers/firmware/efi/efi.c79
-rw-r--r--include/linux/efi.h9
3 files changed, 95 insertions, 0 deletions
diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig
index b0fc7c79dfbb..0d32596ad092 100644
--- a/drivers/firmware/efi/Kconfig
+++ b/drivers/firmware/efi/Kconfig
@@ -36,4 +36,11 @@ config EFI_VARS_PSTORE_DEFAULT_DISABLE
backend for pstore by default. This setting can be overridden
using the efivars module's pstore_disable parameter.
+config EFI_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
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 2e2fbdec0845..0c98165c1cd7 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -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 = {
@@ -272,3 +274,80 @@ int __init efi_config_init(efi_config_table_type_t *arch_tables)
early_iounmap(config_tables, efi.systab->nr_tables * sz);
return 0;
}
+
+#ifdef CONFIG_EFI_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_EFI_PARAMS_FROM_FDT */
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 115b15b27ba9..05111092d728 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -478,6 +478,14 @@ 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;
@@ -605,6 +613,7 @@ extern void efi_initialize_iomem_resources(struct resource *code_resource,
extern unsigned long efi_get_time(void);
extern int efi_set_rtc_mmss(unsigned long nowtime);
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;
/**