Commit ac5abc70 authored by Ard Biesheuvel's avatar Ard Biesheuvel
Browse files

efi/arm: Move FDT param discovery code out of efi.c 



On ARM systems, we discover the UEFI system table address and memory
map address from the /chosen node in the device tree, or in the Xen
case, from a similar node under /hypervisor.

Before making some functional changes to that code, move it into its
own file that only gets built if CONFIG_EFI_PARAMS_FROM_FDT=y.

Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
parent 97aa2765

drivers/firmware/efi/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ KASAN_SANITIZE_runtime-wrappers.o := n 
obj-$(CONFIG_ACPI_BGRT) 		+= efi-bgrt.o

obj-$(CONFIG_EFI)			+= efi.o vars.o reboot.o memattr.o tpm.o

obj-$(CONFIG_EFI)			+= capsule.o memmap.o

obj-$(CONFIG_EFI_PARAMS_FROM_FDT)	+= fdtparams.o

obj-$(CONFIG_EFI_VARS)			+= efivars.o

obj-$(CONFIG_EFI_ESRT)			+= esrt.o

obj-$(CONFIG_EFI_VARS_PSTORE)		+= efi-pstore.o

drivers/firmware/efi/efi.c

+0 −135
Original line number Diff line number Diff line
@@ -20,7 +20,6 @@ 
#include <linux/device.h>

#include <linux/efi.h>

#include <linux/of.h>

#include <linux/of_fdt.h>

#include <linux/io.h>

#include <linux/kexec.h>

#include <linux/platform_device.h>
@@ -646,140 +645,6 @@ static int __init efi_load_efivars(void) 
device_initcall(efi_load_efivars);

#endif



#ifdef CONFIG_EFI_PARAMS_FROM_FDT



#define UEFI_PARAM(name, prop, field)			   \

	{						   \

		{ name },				   \

		{ prop },				   \

		offsetof(struct efi_fdt_params, field),    \

		sizeof_field(struct efi_fdt_params, field) \

	}



struct params {

	const char name[32];

	const char propname[32];

	int offset;

	int size;

};



static __initdata struct params fdt_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)

};



static __initdata struct params xen_fdt_params[] = {

	UEFI_PARAM("System Table", "xen,uefi-system-table", system_table),

	UEFI_PARAM("MemMap Address", "xen,uefi-mmap-start", mmap),

	UEFI_PARAM("MemMap Size", "xen,uefi-mmap-size", mmap_size),

	UEFI_PARAM("MemMap Desc. Size", "xen,uefi-mmap-desc-size", desc_size),

	UEFI_PARAM("MemMap Desc. Version", "xen,uefi-mmap-desc-ver", desc_ver)

};



#define EFI_FDT_PARAMS_SIZE	ARRAY_SIZE(fdt_params)



static __initdata struct {

	const char *uname;

	const char *subnode;

	struct params *params;

} dt_params[] = {

	{ "hypervisor", "uefi", xen_fdt_params },

	{ "chosen", NULL, fdt_params },

};



struct param_info {

	int found;

	void *params;

	const char *missing;

};



static int __init __find_uefi_params(unsigned long node,

				     struct param_info *info,

				     struct params *params)

{

	const void *prop;

	void *dest;

	u64 val;

	int i, len;



	for (i = 0; i < EFI_FDT_PARAMS_SIZE; i++) {

		prop = of_get_flat_dt_prop(node, params[i].propname, &len);

		if (!prop) {

			info->missing = params[i].name;

			return 0;

		}



		dest = info->params + params[i].offset;

		info->found++;



		val = of_read_number(prop, len / sizeof(u32));



		if (params[i].size == sizeof(u32))

			*(u32 *)dest = val;

		else

			*(u64 *)dest = val;



		if (efi_enabled(EFI_DBG))

			pr_info("  %s: 0x%0*llx\n", params[i].name,

				params[i].size * 2, val);

	}



	return 1;

}



static int __init fdt_find_uefi_params(unsigned long node, const char *uname,

				       int depth, void *data)

{

	struct param_info *info = data;

	int i;



	for (i = 0; i < ARRAY_SIZE(dt_params); i++) {

		const char *subnode = dt_params[i].subnode;



		if (depth != 1 || strcmp(uname, dt_params[i].uname) != 0) {

			info->missing = dt_params[i].params[0].name;

			continue;

		}



		if (subnode) {

			int err = of_get_flat_dt_subnode_by_name(node, subnode);



			if (err < 0)

				return 0;



			node = err;

		}



		return __find_uefi_params(node, info, dt_params[i].params);

	}



	return 0;

}



int __init efi_get_fdt_params(struct efi_fdt_params *params)

{

	struct param_info info;

	int ret;



	pr_info("Getting EFI parameters from FDT:\n");



	info.found = 0;

	info.params = params;



	ret = of_scan_flat_dt(fdt_find_uefi_params, &info);

	if (!info.found)

		pr_info("UEFI not found.\n");

	else if (!ret)

		pr_err("Can't find '%s' in device tree!\n",

		       info.missing);



	return ret;

}

#endif /* CONFIG_EFI_PARAMS_FROM_FDT */



static __initdata char memory_type_name[][20] = {

	"Reserved",

	"Loader Code",

drivers/firmware/efi/fdtparams.c

0 → 100644
+142 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only



#define pr_fmt(fmt) "efi: " fmt



#include <linux/module.h>

#include <linux/init.h>

#include <linux/efi.h>

#include <linux/of.h>

#include <linux/of_fdt.h>



#include <asm/early_ioremap.h>



#define UEFI_PARAM(name, prop, field)			   \

	{						   \

		{ name },				   \

		{ prop },				   \

		offsetof(struct efi_fdt_params, field),    \

		sizeof_field(struct efi_fdt_params, field) \

	}



struct params {

	const char name[32];

	const char propname[32];

	int offset;

	int size;

};



static __initdata struct params fdt_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)

};



static __initdata struct params xen_fdt_params[] = {

	UEFI_PARAM("System Table", "xen,uefi-system-table", system_table),

	UEFI_PARAM("MemMap Address", "xen,uefi-mmap-start", mmap),

	UEFI_PARAM("MemMap Size", "xen,uefi-mmap-size", mmap_size),

	UEFI_PARAM("MemMap Desc. Size", "xen,uefi-mmap-desc-size", desc_size),

	UEFI_PARAM("MemMap Desc. Version", "xen,uefi-mmap-desc-ver", desc_ver)

};



#define EFI_FDT_PARAMS_SIZE	ARRAY_SIZE(fdt_params)



static __initdata struct {

	const char *uname;

	const char *subnode;

	struct params *params;

} dt_params[] = {

	{ "hypervisor", "uefi", xen_fdt_params },

	{ "chosen", NULL, fdt_params },

};



struct param_info {

	int found;

	void *params;

	const char *missing;

};



static int __init __find_uefi_params(unsigned long node,

				     struct param_info *info,

				     struct params *params)

{

	const void *prop;

	void *dest;

	u64 val;

	int i, len;



	for (i = 0; i < EFI_FDT_PARAMS_SIZE; i++) {

		prop = of_get_flat_dt_prop(node, params[i].propname, &len);

		if (!prop) {

			info->missing = params[i].name;

			return 0;

		}



		dest = info->params + params[i].offset;

		info->found++;



		val = of_read_number(prop, len / sizeof(u32));



		if (params[i].size == sizeof(u32))

			*(u32 *)dest = val;

		else

			*(u64 *)dest = val;



		if (efi_enabled(EFI_DBG))

			pr_info("  %s: 0x%0*llx\n", params[i].name,

				params[i].size * 2, val);

	}



	return 1;

}



static int __init fdt_find_uefi_params(unsigned long node, const char *uname,

				       int depth, void *data)

{

	struct param_info *info = data;

	int i;



	for (i = 0; i < ARRAY_SIZE(dt_params); i++) {

		const char *subnode = dt_params[i].subnode;



		if (depth != 1 || strcmp(uname, dt_params[i].uname) != 0) {

			info->missing = dt_params[i].params[0].name;

			continue;

		}



		if (subnode) {

			int err = of_get_flat_dt_subnode_by_name(node, subnode);



			if (err < 0)

				return 0;



			node = err;

		}



		return __find_uefi_params(node, info, dt_params[i].params);

	}



	return 0;

}



int __init efi_get_fdt_params(struct efi_fdt_params *params)

{

	struct param_info info;

	int ret;



	pr_info("Getting EFI parameters from FDT:\n");



	info.found = 0;

	info.params = params;



	ret = of_scan_flat_dt(fdt_find_uefi_params, &info);

	if (!info.found)

		pr_info("UEFI not found.\n");

	else if (!ret)

		pr_err("Can't find '%s' in device tree!\n",

		       info.missing);



	return ret;

}