From 0302f71c0aa59571ac306f93068fbbfe65ea349b Mon Sep 17 00:00:00 2001 From: Mark Salter Date: Mon, 30 Dec 2013 12:12:12 -0500 Subject: [PATCH] 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 Signed-off-by: Leif Lindholm Acked-by: Catalin Marinas Signed-off-by: Matt Fleming --- drivers/firmware/efi/Kconfig | 7 ++++ drivers/firmware/efi/efi.c | 79 ++++++++++++++++++++++++++++++++++++ include/linux/efi.h | 9 ++++ 3 files changed, 95 insertions(+) diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index 1e75f48b61f8..d420ae2d3413 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -47,6 +47,13 @@ config EFI_RUNTIME_MAP See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map. +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 config UEFI_CPER diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index af20f1712337..cd36deb619fa 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -20,6 +20,8 @@ #include #include #include +#include +#include #include 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_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 6a4d8e27d1d7..cd0172e796cb 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -664,6 +664,14 @@ 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; u32 parent_handle; @@ -861,6 +869,7 @@ 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 */ -- 2.20.1