[linux-2.6-block.git] / drivers / firmware / efi / libstub / arm-stub.c

/*
 * EFI stub implementation that is shared by arm and arm64 architectures.
 * This should be #included by the EFI stub implementation files.
 *
 * Copyright (C) 2013,2014 Linaro Limited
 *     Roy Franz <roy.franz@linaro.org
 * Copyright (C) 2013 Red Hat, Inc.
 *     Mark Salter <msalter@redhat.com>
 *
 * This file is part of the Linux kernel, and is made available under the
 * terms of the GNU General Public License version 2.
 *
 */

#include <linux/efi.h>
#include <linux/sort.h>
#include <asm/efi.h>

#include "efistub.h"

bool __nokaslr;

static int efi_secureboot_enabled(efi_system_table_t *sys_table_arg)
{
	static efi_guid_t const var_guid = EFI_GLOBAL_VARIABLE_GUID;
	static efi_char16_t const var_name[] = {
		'S', 'e', 'c', 'u', 'r', 'e', 'B', 'o', 'o', 't', 0 };

	efi_get_variable_t *f_getvar = sys_table_arg->runtime->get_variable;
	unsigned long size = sizeof(u8);
	efi_status_t status;
	u8 val;

	status = f_getvar((efi_char16_t *)var_name, (efi_guid_t *)&var_guid,
			  NULL, &size, &val);

	switch (status) {
	case EFI_SUCCESS:
		return val;
	case EFI_NOT_FOUND:
		return 0;
	default:
		return 1;
	}
}

efi_status_t efi_open_volume(efi_system_table_t *sys_table_arg,
			     void *__image, void **__fh)
{
	efi_file_io_interface_t *io;
	efi_loaded_image_t *image = __image;
	efi_file_handle_t *fh;
	efi_guid_t fs_proto = EFI_FILE_SYSTEM_GUID;
	efi_status_t status;
	void *handle = (void *)(unsigned long)image->device_handle;

	status = sys_table_arg->boottime->handle_protocol(handle,
				 &fs_proto, (void **)&io);
	if (status != EFI_SUCCESS) {
		efi_printk(sys_table_arg, "Failed to handle fs_proto\n");
		return status;
	}

	status = io->open_volume(io, &fh);
	if (status != EFI_SUCCESS)
		efi_printk(sys_table_arg, "Failed to open volume\n");

	*__fh = fh;
	return status;
}

efi_status_t efi_file_close(void *handle)
{
	efi_file_handle_t *fh = handle;

	return fh->close(handle);
}

efi_status_t
efi_file_read(void *handle, unsigned long *size, void *addr)
{
	efi_file_handle_t *fh = handle;

	return fh->read(handle, size, addr);
}


efi_status_t
efi_file_size(efi_system_table_t *sys_table_arg, void *__fh,
	      efi_char16_t *filename_16, void **handle, u64 *file_sz)
{
	efi_file_handle_t *h, *fh = __fh;
	efi_file_info_t *info;
	efi_status_t status;
	efi_guid_t info_guid = EFI_FILE_INFO_ID;
	unsigned long info_sz;

	status = fh->open(fh, &h, filename_16, EFI_FILE_MODE_READ, (u64)0);
	if (status != EFI_SUCCESS) {
		efi_printk(sys_table_arg, "Failed to open file: ");
		efi_char16_printk(sys_table_arg, filename_16);
		efi_printk(sys_table_arg, "\n");
		return status;
	}

	*handle = h;

	info_sz = 0;
	status = h->get_info(h, &info_guid, &info_sz, NULL);
	if (status != EFI_BUFFER_TOO_SMALL) {
		efi_printk(sys_table_arg, "Failed to get file info size\n");
		return status;
	}

grow:
	status = sys_table_arg->boottime->allocate_pool(EFI_LOADER_DATA,
				 info_sz, (void **)&info);
	if (status != EFI_SUCCESS) {
		efi_printk(sys_table_arg, "Failed to alloc mem for file info\n");
		return status;
	}

	status = h->get_info(h, &info_guid, &info_sz,
						   info);
	if (status == EFI_BUFFER_TOO_SMALL) {
		sys_table_arg->boottime->free_pool(info);
		goto grow;
	}

	*file_sz = info->file_size;
	sys_table_arg->boottime->free_pool(info);

	if (status != EFI_SUCCESS)
		efi_printk(sys_table_arg, "Failed to get initrd info\n");

	return status;
}


void efi_char16_printk(efi_system_table_t *sys_table_arg,
			      efi_char16_t *str)
{
	struct efi_simple_text_output_protocol *out;

	out = (struct efi_simple_text_output_protocol *)sys_table_arg->con_out;
	out->output_string(out, str);
}


/*
 * This function handles the architcture specific differences between arm and
 * arm64 regarding where the kernel image must be loaded and any memory that
 * must be reserved. On failure it is required to free all
 * all allocations it has made.
 */
efi_status_t handle_kernel_image(efi_system_table_t *sys_table,
				 unsigned long *image_addr,
				 unsigned long *image_size,
				 unsigned long *reserve_addr,
				 unsigned long *reserve_size,
				 unsigned long dram_base,
				 efi_loaded_image_t *image);
/*
 * EFI entry point for the arm/arm64 EFI stubs.  This is the entrypoint
 * that is described in the PE/COFF header.  Most of the code is the same
 * for both archictectures, with the arch-specific code provided in the
 * handle_kernel_image() function.
 */
unsigned long efi_entry(void *handle, efi_system_table_t *sys_table,
			       unsigned long *image_addr)
{
	efi_loaded_image_t *image;
	efi_status_t status;
	unsigned long image_size = 0;
	unsigned long dram_base;
	/* addr/point and size pairs for memory management*/
	unsigned long initrd_addr;
	u64 initrd_size = 0;
	unsigned long fdt_addr = 0;  /* Original DTB */
	unsigned long fdt_size = 0;
	char *cmdline_ptr = NULL;
	int cmdline_size = 0;
	unsigned long new_fdt_addr;
	efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID;
	unsigned long reserve_addr = 0;
	unsigned long reserve_size = 0;

	/* Check if we were booted by the EFI firmware */
	if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
		goto fail;

	pr_efi(sys_table, "Booting Linux Kernel...\n");

	status = check_platform_features(sys_table);
	if (status != EFI_SUCCESS)
		goto fail;

	/*
	 * Get a handle to the loaded image protocol.  This is used to get
	 * information about the running image, such as size and the command
	 * line.
	 */
	status = sys_table->boottime->handle_protocol(handle,
					&loaded_image_proto, (void *)&image);
	if (status != EFI_SUCCESS) {
		pr_efi_err(sys_table, "Failed to get loaded image protocol\n");
		goto fail;
	}

	dram_base = get_dram_base(sys_table);
	if (dram_base == EFI_ERROR) {
		pr_efi_err(sys_table, "Failed to find DRAM base\n");
		goto fail;
	}

	/*
	 * Get the command line from EFI, using the LOADED_IMAGE
	 * protocol. We are going to copy the command line into the
	 * device tree, so this can be allocated anywhere.
	 */
	cmdline_ptr = efi_convert_cmdline(sys_table, image, &cmdline_size);
	if (!cmdline_ptr) {
		pr_efi_err(sys_table, "getting command line via LOADED_IMAGE_PROTOCOL\n");
		goto fail;
	}

	/* check whether 'nokaslr' was passed on the command line */
	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
		static const u8 default_cmdline[] = CONFIG_CMDLINE;
		const u8 *str, *cmdline = cmdline_ptr;

		if (IS_ENABLED(CONFIG_CMDLINE_FORCE))
			cmdline = default_cmdline;
		str = strstr(cmdline, "nokaslr");
		if (str == cmdline || (str > cmdline && *(str - 1) == ' '))
			__nokaslr = true;
	}

	status = handle_kernel_image(sys_table, image_addr, &image_size,
				     &reserve_addr,
				     &reserve_size,
				     dram_base, image);
	if (status != EFI_SUCCESS) {
		pr_efi_err(sys_table, "Failed to relocate kernel\n");
		goto fail_free_cmdline;
	}

	status = efi_parse_options(cmdline_ptr);
	if (status != EFI_SUCCESS)
		pr_efi_err(sys_table, "Failed to parse EFI cmdline options\n");

	/*
	 * Unauthenticated device tree data is a security hazard, so
	 * ignore 'dtb=' unless UEFI Secure Boot is disabled.
	 */
	if (efi_secureboot_enabled(sys_table)) {
		pr_efi(sys_table, "UEFI Secure Boot is enabled.\n");
	} else {
		status = handle_cmdline_files(sys_table, image, cmdline_ptr,
					      "dtb=",
					      ~0UL, &fdt_addr, &fdt_size);

		if (status != EFI_SUCCESS) {
			pr_efi_err(sys_table, "Failed to load device tree!\n");
			goto fail_free_image;
		}
	}

	if (fdt_addr) {
		pr_efi(sys_table, "Using DTB from command line\n");
	} else {
		/* Look for a device tree configuration table entry. */
		fdt_addr = (uintptr_t)get_fdt(sys_table, &fdt_size);
		if (fdt_addr)
			pr_efi(sys_table, "Using DTB from configuration table\n");
	}

	if (!fdt_addr)
		pr_efi(sys_table, "Generating empty DTB\n");

	status = handle_cmdline_files(sys_table, image, cmdline_ptr,
				      "initrd=", dram_base + SZ_512M,
				      (unsigned long *)&initrd_addr,
				      (unsigned long *)&initrd_size);
	if (status != EFI_SUCCESS)
		pr_efi_err(sys_table, "Failed initrd from command line!\n");

	new_fdt_addr = fdt_addr;
	status = allocate_new_fdt_and_exit_boot(sys_table, handle,
				&new_fdt_addr, dram_base + MAX_FDT_OFFSET,
				initrd_addr, initrd_size, cmdline_ptr,
				fdt_addr, fdt_size);

	/*
	 * If all went well, we need to return the FDT address to the
	 * calling function so it can be passed to kernel as part of
	 * the kernel boot protocol.
	 */
	if (status == EFI_SUCCESS)
		return new_fdt_addr;

	pr_efi_err(sys_table, "Failed to update FDT and exit boot services\n");

	efi_free(sys_table, initrd_size, initrd_addr);
	efi_free(sys_table, fdt_size, fdt_addr);

fail_free_image:
	efi_free(sys_table, image_size, *image_addr);
	efi_free(sys_table, reserve_size, reserve_addr);
fail_free_cmdline:
	efi_free(sys_table, cmdline_size, (unsigned long)cmdline_ptr);
fail:
	return EFI_ERROR;
}

/*
 * This is the base address at which to start allocating virtual memory ranges
 * for UEFI Runtime Services. This is in the low TTBR0 range so that we can use
 * any allocation we choose, and eliminate the risk of a conflict after kexec.
 * The value chosen is the largest non-zero power of 2 suitable for this purpose
 * both on 32-bit and 64-bit ARM CPUs, to maximize the likelihood that it can
 * be mapped efficiently.
 * Since 32-bit ARM could potentially execute with a 1G/3G user/kernel split,
 * map everything below 1 GB.
 */
#define EFI_RT_VIRTUAL_BASE	SZ_512M

static int cmp_mem_desc(const void *l, const void *r)
{
	const efi_memory_desc_t *left = l, *right = r;

	return (left->phys_addr > right->phys_addr) ? 1 : -1;
}

/*
 * Returns whether region @left ends exactly where region @right starts,
 * or false if either argument is NULL.
 */
static bool regions_are_adjacent(efi_memory_desc_t *left,
				 efi_memory_desc_t *right)
{
	u64 left_end;

	if (left == NULL || right == NULL)
		return false;

	left_end = left->phys_addr + left->num_pages * EFI_PAGE_SIZE;

	return left_end == right->phys_addr;
}

/*
 * Returns whether region @left and region @right have compatible memory type
 * mapping attributes, and are both EFI_MEMORY_RUNTIME regions.
 */
static bool regions_have_compatible_memory_type_attrs(efi_memory_desc_t *left,
						      efi_memory_desc_t *right)
{
	static const u64 mem_type_mask = EFI_MEMORY_WB | EFI_MEMORY_WT |
					 EFI_MEMORY_WC | EFI_MEMORY_UC |
					 EFI_MEMORY_RUNTIME;

	return ((left->attribute ^ right->attribute) & mem_type_mask) == 0;
}

/*
 * efi_get_virtmap() - create a virtual mapping for the EFI memory map
 *
 * This function populates the virt_addr fields of all memory region descriptors
 * in @memory_map whose EFI_MEMORY_RUNTIME attribute is set. Those descriptors
 * are also copied to @runtime_map, and their total count is returned in @count.
 */
void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size,
		     unsigned long desc_size, efi_memory_desc_t *runtime_map,
		     int *count)
{
	u64 efi_virt_base = EFI_RT_VIRTUAL_BASE;
	efi_memory_desc_t *in, *prev = NULL, *out = runtime_map;
	int l;

	/*
	 * To work around potential issues with the Properties Table feature
	 * introduced in UEFI 2.5, which may split PE/COFF executable images
	 * in memory into several RuntimeServicesCode and RuntimeServicesData
	 * regions, we need to preserve the relative offsets between adjacent
	 * EFI_MEMORY_RUNTIME regions with the same memory type attributes.
	 * The easiest way to find adjacent regions is to sort the memory map
	 * before traversing it.
	 */
	sort(memory_map, map_size / desc_size, desc_size, cmp_mem_desc, NULL);

	for (l = 0; l < map_size; l += desc_size, prev = in) {
		u64 paddr, size;

		in = (void *)memory_map + l;
		if (!(in->attribute & EFI_MEMORY_RUNTIME))
			continue;

		paddr = in->phys_addr;
		size = in->num_pages * EFI_PAGE_SIZE;

		/*
		 * Make the mapping compatible with 64k pages: this allows
		 * a 4k page size kernel to kexec a 64k page size kernel and
		 * vice versa.
		 */
		if (!regions_are_adjacent(prev, in) ||
		    !regions_have_compatible_memory_type_attrs(prev, in)) {

			paddr = round_down(in->phys_addr, SZ_64K);
			size += in->phys_addr - paddr;

			/*
			 * Avoid wasting memory on PTEs by choosing a virtual
			 * base that is compatible with section mappings if this
			 * region has the appropriate size and physical
			 * alignment. (Sections are 2 MB on 4k granule kernels)
			 */
			if (IS_ALIGNED(in->phys_addr, SZ_2M) && size >= SZ_2M)
				efi_virt_base = round_up(efi_virt_base, SZ_2M);
			else
				efi_virt_base = round_up(efi_virt_base, SZ_64K);
		}

		in->virt_addr = efi_virt_base + in->phys_addr - paddr;
		efi_virt_base += size;

		memcpy(out, in, desc_size);
		out = (void *)out + desc_size;
		++*count;
	}
}
Commit	Line	Data
3c7f2550 MS	1	/*
	2	* EFI stub implementation that is shared by arm and arm64 architectures.
	3	* This should be #included by the EFI stub implementation files.
	4	*
	5	* Copyright (C) 2013,2014 Linaro Limited
	6	* Roy Franz <roy.franz@linaro.org
	7	* Copyright (C) 2013 Red Hat, Inc.
	8	* Mark Salter <msalter@redhat.com>
	9	*
	10	* This file is part of the Linux kernel, and is made available under the
	11	* terms of the GNU General Public License version 2.
	12	*
	13	*/
	14
bd669475	15	#include <linux/efi.h>
0ce3cc00	16	#include <linux/sort.h>
bd669475 AB	17	#include <asm/efi.h>
	18
	19	#include "efistub.h"
	20
2b5fe07a AB	21	bool __nokaslr;
2b5fe07a AB	22
ddeeefe2	23	static int efi_secureboot_enabled(efi_system_table_t *sys_table_arg)
345c736e	24	{
ddeeefe2 AB	25	static efi_guid_t const var_guid = EFI_GLOBAL_VARIABLE_GUID;
ddeeefe2 AB	26	static efi_char16_t const var_name[] = {
345c736e AB	27	'S', 'e', 'c', 'u', 'r', 'e', 'B', 'o', 'o', 't', 0 };
	28
	29	efi_get_variable_t *f_getvar = sys_table_arg->runtime->get_variable;
	30	unsigned long size = sizeof(u8);
	31	efi_status_t status;
	32	u8 val;
	33
	34	status = f_getvar((efi_char16_t )var_name, (efi_guid_t )&var_guid,
	35	NULL, &size, &val);
	36
	37	switch (status) {
	38	case EFI_SUCCESS:
	39	return val;
	40	case EFI_NOT_FOUND:
	41	return 0;
	42	default:
	43	return 1;
	44	}
	45	}
	46
bd669475 AB	47	efi_status_t efi_open_volume(efi_system_table_t *sys_table_arg,
bd669475 AB	48	void __image, void *__fh)
3c7f2550 MS	49	{
	50	efi_file_io_interface_t *io;
	51	efi_loaded_image_t *image = __image;
	52	efi_file_handle_t *fh;
	53	efi_guid_t fs_proto = EFI_FILE_SYSTEM_GUID;
	54	efi_status_t status;
	55	void handle = (void )(unsigned long)image->device_handle;
	56
	57	status = sys_table_arg->boottime->handle_protocol(handle,
	58	&fs_proto, (void **)&io);
	59	if (status != EFI_SUCCESS) {
	60	efi_printk(sys_table_arg, "Failed to handle fs_proto\n");
	61	return status;
	62	}
	63
	64	status = io->open_volume(io, &fh);
	65	if (status != EFI_SUCCESS)
	66	efi_printk(sys_table_arg, "Failed to open volume\n");
	67
	68	*__fh = fh;
	69	return status;
	70	}
bd669475 AB	71
bd669475 AB	72	efi_status_t efi_file_close(void *handle)
3c7f2550 MS	73	{
	74	efi_file_handle_t *fh = handle;
	75
	76	return fh->close(handle);
	77	}
	78
bd669475	79	efi_status_t
3c7f2550 MS	80	efi_file_read(void handle, unsigned long size, void *addr)
	81	{
	82	efi_file_handle_t *fh = handle;
	83
	84	return fh->read(handle, size, addr);
	85	}
	86
	87
bd669475	88	efi_status_t
3c7f2550 MS	89	efi_file_size(efi_system_table_t sys_table_arg, void __fh,
	90	efi_char16_t filename_16, void handle, u64 file_sz)
	91	{
	92	efi_file_handle_t h, fh = __fh;
	93	efi_file_info_t *info;
	94	efi_status_t status;
	95	efi_guid_t info_guid = EFI_FILE_INFO_ID;
	96	unsigned long info_sz;
	97
	98	status = fh->open(fh, &h, filename_16, EFI_FILE_MODE_READ, (u64)0);
	99	if (status != EFI_SUCCESS) {
	100	efi_printk(sys_table_arg, "Failed to open file: ");
	101	efi_char16_printk(sys_table_arg, filename_16);
	102	efi_printk(sys_table_arg, "\n");
	103	return status;
	104	}
	105
	106	*handle = h;
	107
	108	info_sz = 0;
	109	status = h->get_info(h, &info_guid, &info_sz, NULL);
	110	if (status != EFI_BUFFER_TOO_SMALL) {
	111	efi_printk(sys_table_arg, "Failed to get file info size\n");
	112	return status;
	113	}
	114
	115	grow:
	116	status = sys_table_arg->boottime->allocate_pool(EFI_LOADER_DATA,
	117	info_sz, (void **)&info);
	118	if (status != EFI_SUCCESS) {
	119	efi_printk(sys_table_arg, "Failed to alloc mem for file info\n");
	120	return status;
	121	}
	122
	123	status = h->get_info(h, &info_guid, &info_sz,
	124	info);
	125	if (status == EFI_BUFFER_TOO_SMALL) {
	126	sys_table_arg->boottime->free_pool(info);
	127	goto grow;
	128	}
	129
	130	*file_sz = info->file_size;
	131	sys_table_arg->boottime->free_pool(info);
	132
	133	if (status != EFI_SUCCESS)
	134	efi_printk(sys_table_arg, "Failed to get initrd info\n");
	135
	136	return status;
	137	}
	138
	139
	140
bd669475	141	void efi_char16_printk(efi_system_table_t *sys_table_arg,
3c7f2550 MS	142	efi_char16_t *str)
	143	{
	144	struct efi_simple_text_output_protocol *out;
	145
	146	out = (struct efi_simple_text_output_protocol *)sys_table_arg->con_out;
	147	out->output_string(out, str);
	148	}
	149
	150
	151	/*
	152	* This function handles the architcture specific differences between arm and
	153	* arm64 regarding where the kernel image must be loaded and any memory that
	154	* must be reserved. On failure it is required to free all
	155	* all allocations it has made.
	156	*/
bd669475 AB	157	efi_status_t handle_kernel_image(efi_system_table_t *sys_table,
	158	unsigned long *image_addr,
	159	unsigned long *image_size,
	160	unsigned long *reserve_addr,
	161	unsigned long *reserve_size,
	162	unsigned long dram_base,
	163	efi_loaded_image_t *image);
3c7f2550 MS	164	/*
	165	* EFI entry point for the arm/arm64 EFI stubs. This is the entrypoint
	166	* that is described in the PE/COFF header. Most of the code is the same
	167	* for both archictectures, with the arch-specific code provided in the
	168	* handle_kernel_image() function.
	169	*/
ddeeefe2	170	unsigned long efi_entry(void handle, efi_system_table_t sys_table,
3c7f2550 MS	171	unsigned long *image_addr)
	172	{
	173	efi_loaded_image_t *image;
	174	efi_status_t status;
	175	unsigned long image_size = 0;
	176	unsigned long dram_base;
	177	/* addr/point and size pairs for memory management*/
	178	unsigned long initrd_addr;
	179	u64 initrd_size = 0;
345c736e	180	unsigned long fdt_addr = 0; /* Original DTB */
a643375f	181	unsigned long fdt_size = 0;
3c7f2550 MS	182	char *cmdline_ptr = NULL;
	183	int cmdline_size = 0;
	184	unsigned long new_fdt_addr;
	185	efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID;
	186	unsigned long reserve_addr = 0;
	187	unsigned long reserve_size = 0;
	188
	189	/* Check if we were booted by the EFI firmware */
	190	if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
	191	goto fail;
	192
	193	pr_efi(sys_table, "Booting Linux Kernel...\n");
	194
b9d6769b AB	195	status = check_platform_features(sys_table);
	196	if (status != EFI_SUCCESS)
	197	goto fail;
	198
3c7f2550 MS	199	/*
	200	* Get a handle to the loaded image protocol. This is used to get
	201	* information about the running image, such as size and the command
	202	* line.
	203	*/
	204	status = sys_table->boottime->handle_protocol(handle,
	205	&loaded_image_proto, (void *)&image);
	206	if (status != EFI_SUCCESS) {
	207	pr_efi_err(sys_table, "Failed to get loaded image protocol\n");
	208	goto fail;
	209	}
	210
	211	dram_base = get_dram_base(sys_table);
	212	if (dram_base == EFI_ERROR) {
	213	pr_efi_err(sys_table, "Failed to find DRAM base\n");
	214	goto fail;
	215	}
3c7f2550 MS	216
	217	/*
	218	* Get the command line from EFI, using the LOADED_IMAGE
	219	* protocol. We are going to copy the command line into the
	220	* device tree, so this can be allocated anywhere.
	221	*/
	222	cmdline_ptr = efi_convert_cmdline(sys_table, image, &cmdline_size);
	223	if (!cmdline_ptr) {
	224	pr_efi_err(sys_table, "getting command line via LOADED_IMAGE_PROTOCOL\n");
2b5fe07a AB	225	goto fail;
	226	}
	227
	228	/* check whether 'nokaslr' was passed on the command line */
	229	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
	230	static const u8 default_cmdline[] = CONFIG_CMDLINE;
	231	const u8 str, cmdline = cmdline_ptr;
	232
	233	if (IS_ENABLED(CONFIG_CMDLINE_FORCE))
	234	cmdline = default_cmdline;
	235	str = strstr(cmdline, "nokaslr");
	236	if (str == cmdline \|\| (str > cmdline && *(str - 1) == ' '))
	237	__nokaslr = true;
	238	}
	239
	240	status = handle_kernel_image(sys_table, image_addr, &image_size,
	241	&reserve_addr,
	242	&reserve_size,
	243	dram_base, image);
	244	if (status != EFI_SUCCESS) {
	245	pr_efi_err(sys_table, "Failed to relocate kernel\n");
	246	goto fail_free_cmdline;
3c7f2550 MS	247	}
3c7f2550 MS	248
5a17dae4 MF	249	status = efi_parse_options(cmdline_ptr);
	250	if (status != EFI_SUCCESS)
	251	pr_efi_err(sys_table, "Failed to parse EFI cmdline options\n");
	252
345c736e AB	253	/*
	254	* Unauthenticated device tree data is a security hazard, so
	255	* ignore 'dtb=' unless UEFI Secure Boot is disabled.
	256	*/
	257	if (efi_secureboot_enabled(sys_table)) {
	258	pr_efi(sys_table, "UEFI Secure Boot is enabled.\n");
	259	} else {
3c7f2550 MS	260	status = handle_cmdline_files(sys_table, image, cmdline_ptr,
3c7f2550 MS	261	"dtb=",
a643375f	262	~0UL, &fdt_addr, &fdt_size);
3c7f2550 MS	263
	264	if (status != EFI_SUCCESS) {
	265	pr_efi_err(sys_table, "Failed to load device tree!\n");
2b5fe07a	266	goto fail_free_image;
3c7f2550 MS	267	}
3c7f2550 MS	268	}
0bcaa904 MR	269
	270	if (fdt_addr) {
	271	pr_efi(sys_table, "Using DTB from command line\n");
	272	} else {
345c736e	273	/* Look for a device tree configuration table entry. */
a643375f	274	fdt_addr = (uintptr_t)get_fdt(sys_table, &fdt_size);
0bcaa904 MR	275	if (fdt_addr)
	276	pr_efi(sys_table, "Using DTB from configuration table\n");
	277	}
	278
	279	if (!fdt_addr)
	280	pr_efi(sys_table, "Generating empty DTB\n");
3c7f2550 MS	281
	282	status = handle_cmdline_files(sys_table, image, cmdline_ptr,
	283	"initrd=", dram_base + SZ_512M,
	284	(unsigned long *)&initrd_addr,
	285	(unsigned long *)&initrd_size);
	286	if (status != EFI_SUCCESS)
	287	pr_efi_err(sys_table, "Failed initrd from command line!\n");
	288
	289	new_fdt_addr = fdt_addr;
	290	status = allocate_new_fdt_and_exit_boot(sys_table, handle,
	291	&new_fdt_addr, dram_base + MAX_FDT_OFFSET,
	292	initrd_addr, initrd_size, cmdline_ptr,
	293	fdt_addr, fdt_size);
	294
	295	/*
	296	* If all went well, we need to return the FDT address to the
	297	* calling function so it can be passed to kernel as part of
	298	* the kernel boot protocol.
	299	*/
	300	if (status == EFI_SUCCESS)
	301	return new_fdt_addr;
	302
	303	pr_efi_err(sys_table, "Failed to update FDT and exit boot services\n");
	304
	305	efi_free(sys_table, initrd_size, initrd_addr);
	306	efi_free(sys_table, fdt_size, fdt_addr);
	307
3c7f2550 MS	308	fail_free_image:
	309	efi_free(sys_table, image_size, *image_addr);
	310	efi_free(sys_table, reserve_size, reserve_addr);
2b5fe07a AB	311	fail_free_cmdline:
2b5fe07a AB	312	efi_free(sys_table, cmdline_size, (unsigned long)cmdline_ptr);
3c7f2550 MS	313	fail:
	314	return EFI_ERROR;
	315	}
f3cdfd23 AB	316
	317	/*
	318	* This is the base address at which to start allocating virtual memory ranges
	319	* for UEFI Runtime Services. This is in the low TTBR0 range so that we can use
	320	* any allocation we choose, and eliminate the risk of a conflict after kexec.
	321	* The value chosen is the largest non-zero power of 2 suitable for this purpose
	322	* both on 32-bit and 64-bit ARM CPUs, to maximize the likelihood that it can
	323	* be mapped efficiently.
81a0bc39 RF	324	* Since 32-bit ARM could potentially execute with a 1G/3G user/kernel split,
81a0bc39 RF	325	* map everything below 1 GB.
f3cdfd23	326	*/
81a0bc39	327	#define EFI_RT_VIRTUAL_BASE SZ_512M
f3cdfd23	328
0ce3cc00 AB	329	static int cmp_mem_desc(const void l, const void r)
	330	{
	331	const efi_memory_desc_t left = l, right = r;
	332
	333	return (left->phys_addr > right->phys_addr) ? 1 : -1;
	334	}
	335
	336	/*
	337	* Returns whether region @left ends exactly where region @right starts,
	338	* or false if either argument is NULL.
	339	*/
	340	static bool regions_are_adjacent(efi_memory_desc_t *left,
	341	efi_memory_desc_t *right)
	342	{
	343	u64 left_end;
	344
	345	if (left == NULL \|\| right == NULL)
	346	return false;
	347
	348	left_end = left->phys_addr + left->num_pages * EFI_PAGE_SIZE;
	349
	350	return left_end == right->phys_addr;
	351	}
	352
	353	/*
	354	* Returns whether region @left and region @right have compatible memory type
	355	* mapping attributes, and are both EFI_MEMORY_RUNTIME regions.
	356	*/
	357	static bool regions_have_compatible_memory_type_attrs(efi_memory_desc_t *left,
	358	efi_memory_desc_t *right)
	359	{
	360	static const u64 mem_type_mask = EFI_MEMORY_WB \| EFI_MEMORY_WT \|
	361	EFI_MEMORY_WC \| EFI_MEMORY_UC \|
	362	EFI_MEMORY_RUNTIME;
	363
	364	return ((left->attribute ^ right->attribute) & mem_type_mask) == 0;
	365	}
	366
f3cdfd23 AB	367	/*
	368	* efi_get_virtmap() - create a virtual mapping for the EFI memory map
	369	*
	370	* This function populates the virt_addr fields of all memory region descriptors
	371	* in @memory_map whose EFI_MEMORY_RUNTIME attribute is set. Those descriptors
	372	* are also copied to @runtime_map, and their total count is returned in @count.
	373	*/
	374	void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size,
	375	unsigned long desc_size, efi_memory_desc_t *runtime_map,
	376	int *count)
	377	{
	378	u64 efi_virt_base = EFI_RT_VIRTUAL_BASE;
0ce3cc00	379	efi_memory_desc_t in, prev = NULL, *out = runtime_map;
f3cdfd23 AB	380	int l;
f3cdfd23 AB	381
0ce3cc00 AB	382	/*
	383	* To work around potential issues with the Properties Table feature
	384	* introduced in UEFI 2.5, which may split PE/COFF executable images
	385	* in memory into several RuntimeServicesCode and RuntimeServicesData
	386	* regions, we need to preserve the relative offsets between adjacent
	387	* EFI_MEMORY_RUNTIME regions with the same memory type attributes.
	388	* The easiest way to find adjacent regions is to sort the memory map
	389	* before traversing it.
	390	*/
	391	sort(memory_map, map_size / desc_size, desc_size, cmp_mem_desc, NULL);
	392
	393	for (l = 0; l < map_size; l += desc_size, prev = in) {
f3cdfd23 AB	394	u64 paddr, size;
f3cdfd23 AB	395
0ce3cc00	396	in = (void *)memory_map + l;
f3cdfd23 AB	397	if (!(in->attribute & EFI_MEMORY_RUNTIME))
	398	continue;
	399
0ce3cc00 AB	400	paddr = in->phys_addr;
	401	size = in->num_pages * EFI_PAGE_SIZE;
	402
f3cdfd23 AB	403	/*
	404	* Make the mapping compatible with 64k pages: this allows
	405	* a 4k page size kernel to kexec a 64k page size kernel and
	406	* vice versa.
	407	*/
0ce3cc00 AB	408	if (!regions_are_adjacent(prev, in) \|\|
	409	!regions_have_compatible_memory_type_attrs(prev, in)) {
	410
	411	paddr = round_down(in->phys_addr, SZ_64K);
	412	size += in->phys_addr - paddr;
	413
	414	/*
	415	* Avoid wasting memory on PTEs by choosing a virtual
	416	* base that is compatible with section mappings if this
	417	* region has the appropriate size and physical
	418	* alignment. (Sections are 2 MB on 4k granule kernels)
	419	*/
	420	if (IS_ALIGNED(in->phys_addr, SZ_2M) && size >= SZ_2M)
	421	efi_virt_base = round_up(efi_virt_base, SZ_2M);
	422	else
	423	efi_virt_base = round_up(efi_virt_base, SZ_64K);
	424	}
f3cdfd23 AB	425
	426	in->virt_addr = efi_virt_base + in->phys_addr - paddr;
	427	efi_virt_base += size;
	428
	429	memcpy(out, in, desc_size);
	430	out = (void *)out + desc_size;
	431	++*count;
	432	}
	433	}