[linux.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 <[email protected]
 * Copyright (C) 2013 Red Hat, Inc.
 *     Mark Salter <[email protected]>
 *
 * 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"

/*
 * 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. (512 MB is a reasonable upper bound for the
 * entire footprint of the UEFI runtime services memory regions)
 */
#define EFI_RT_VIRTUAL_BASE	SZ_512M
#define EFI_RT_VIRTUAL_SIZE	SZ_512M

#ifdef CONFIG_ARM64
# define EFI_RT_VIRTUAL_LIMIT	TASK_SIZE_64
#else
# define EFI_RT_VIRTUAL_LIMIT	TASK_SIZE
#endif

static u64 virtmap_base = EFI_RT_VIRTUAL_BASE;

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);
}

static struct screen_info *setup_graphics(efi_system_table_t *sys_table_arg)
{
	efi_guid_t gop_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
	efi_status_t status;
	unsigned long size;
	void **gop_handle = NULL;
	struct screen_info *si = NULL;

	size = 0;
	status = efi_call_early(locate_handle, EFI_LOCATE_BY_PROTOCOL,
				&gop_proto, NULL, &size, gop_handle);
	if (status == EFI_BUFFER_TOO_SMALL) {
		si = alloc_screen_info(sys_table_arg);
		if (!si)
			return NULL;
		efi_setup_gop(sys_table_arg, si, &gop_proto, size);
	}
	return si;
}

void install_memreserve_table(efi_system_table_t *sys_table_arg)
{
	struct linux_efi_memreserve *rsv;
	efi_guid_t memreserve_table_guid = LINUX_EFI_MEMRESERVE_TABLE_GUID;
	efi_status_t status;

	if (IS_ENABLED(CONFIG_ARM))
		return;

	status = efi_call_early(allocate_pool, EFI_LOADER_DATA, sizeof(*rsv),
				(void **)&rsv);
	if (status != EFI_SUCCESS) {
		pr_efi_err(sys_table_arg, "Failed to allocate memreserve entry!\n");
		return;
	}

	rsv->next = 0;
	rsv->base = 0;
	rsv->size = 0;

	status = efi_call_early(install_configuration_table,
				&memreserve_table_guid,
				rsv);
	if (status != EFI_SUCCESS)
		pr_efi_err(sys_table_arg, "Failed to install memreserve config table!\n");
}


/*
 * 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;
	enum efi_secureboot_mode secure_boot;
	struct screen_info *si;

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

	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;
	}

	if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) ||
	    IS_ENABLED(CONFIG_CMDLINE_FORCE) ||
	    cmdline_size == 0)
		efi_parse_options(CONFIG_CMDLINE);

	if (!IS_ENABLED(CONFIG_CMDLINE_FORCE) && cmdline_size > 0)
		efi_parse_options(cmdline_ptr);

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

	si = setup_graphics(sys_table);

	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;
	}

	/* Ask the firmware to clear memory on unclean shutdown */
	efi_enable_reset_attack_mitigation(sys_table);

	secure_boot = efi_get_secureboot(sys_table);

	/*
	 * Unauthenticated device tree data is a security hazard, so ignore
	 * 'dtb=' unless UEFI Secure Boot is disabled.  We assume that secure
	 * boot is enabled if we can't determine its state.
	 */
	if (!IS_ENABLED(CONFIG_EFI_ARMSTUB_DTB_LOADER) ||
	     secure_boot != efi_secureboot_mode_disabled) {
		if (strstr(cmdline_ptr, "dtb="))
			pr_efi(sys_table, "Ignoring DTB from command line.\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=",
				      efi_get_max_initrd_addr(dram_base,
							      *image_addr),
				      (unsigned long *)&initrd_addr,
				      (unsigned long *)&initrd_size);
	if (status != EFI_SUCCESS)
		pr_efi_err(sys_table, "Failed initrd from command line!\n");

	efi_random_get_seed(sys_table);

	/* hibernation expects the runtime regions to stay in the same place */
	if (!IS_ENABLED(CONFIG_HIBERNATION) && !nokaslr()) {
		/*
		 * Randomize the base of the UEFI runtime services region.
		 * Preserve the 2 MB alignment of the region by taking a
		 * shift of 21 bit positions into account when scaling
		 * the headroom value using a 32-bit random value.
		 */
		static const u64 headroom = EFI_RT_VIRTUAL_LIMIT -
					    EFI_RT_VIRTUAL_BASE -
					    EFI_RT_VIRTUAL_SIZE;
		u32 rnd;

		status = efi_get_random_bytes(sys_table, sizeof(rnd),
					      (u8 *)&rnd);
		if (status == EFI_SUCCESS) {
			virtmap_base = EFI_RT_VIRTUAL_BASE +
				       (((headroom >> 21) * rnd) >> (32 - 21));
		}
	}

	install_memreserve_table(sys_table);

	new_fdt_addr = fdt_addr;
	status = allocate_new_fdt_and_exit_boot(sys_table, handle,
				&new_fdt_addr, efi_get_max_fdt_addr(dram_base),
				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:
	free_screen_info(sys_table, si);
	efi_free(sys_table, cmdline_size, (unsigned long)cmdline_ptr);
fail:
	return EFI_ERROR;
}

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 = virtmap_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.
	 */
	if (IS_ENABLED(CONFIG_ARM64))
		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 ((IS_ENABLED(CONFIG_ARM64) &&
		     !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 <[email protected]
	7	* Copyright (C) 2013 Red Hat, Inc.
	8	* Mark Salter <[email protected]>
	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
e69176d6 AB	21	/*
	22	* This is the base address at which to start allocating virtual memory ranges
	23	* for UEFI Runtime Services. This is in the low TTBR0 range so that we can use
	24	* any allocation we choose, and eliminate the risk of a conflict after kexec.
	25	* The value chosen is the largest non-zero power of 2 suitable for this purpose
	26	* both on 32-bit and 64-bit ARM CPUs, to maximize the likelihood that it can
	27	* be mapped efficiently.
	28	* Since 32-bit ARM could potentially execute with a 1G/3G user/kernel split,
	29	* map everything below 1 GB. (512 MB is a reasonable upper bound for the
	30	* entire footprint of the UEFI runtime services memory regions)
	31	*/
	32	#define EFI_RT_VIRTUAL_BASE SZ_512M
	33	#define EFI_RT_VIRTUAL_SIZE SZ_512M
	34
197decef AB	35	#ifdef CONFIG_ARM64
	36	# define EFI_RT_VIRTUAL_LIMIT TASK_SIZE_64
	37	#else
	38	# define EFI_RT_VIRTUAL_LIMIT TASK_SIZE
	39	#endif
	40
e69176d6 AB	41	static u64 virtmap_base = EFI_RT_VIRTUAL_BASE;
e69176d6 AB	42
bd669475	43	void efi_char16_printk(efi_system_table_t *sys_table_arg,
3c7f2550 MS	44	efi_char16_t *str)
	45	{
	46	struct efi_simple_text_output_protocol *out;
	47
	48	out = (struct efi_simple_text_output_protocol *)sys_table_arg->con_out;
	49	out->output_string(out, str);
	50	}
	51
f0827e18 AB	52	static struct screen_info setup_graphics(efi_system_table_t sys_table_arg)
	53	{
	54	efi_guid_t gop_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
	55	efi_status_t status;
	56	unsigned long size;
	57	void **gop_handle = NULL;
	58	struct screen_info *si = NULL;
	59
	60	size = 0;
	61	status = efi_call_early(locate_handle, EFI_LOCATE_BY_PROTOCOL,
	62	&gop_proto, NULL, &size, gop_handle);
	63	if (status == EFI_BUFFER_TOO_SMALL) {
	64	si = alloc_screen_info(sys_table_arg);
	65	if (!si)
	66	return NULL;
	67	efi_setup_gop(sys_table_arg, si, &gop_proto, size);
	68	}
	69	return si;
	70	}
3c7f2550	71
b844470f AB	72	void install_memreserve_table(efi_system_table_t *sys_table_arg)
	73	{
	74	struct linux_efi_memreserve *rsv;
	75	efi_guid_t memreserve_table_guid = LINUX_EFI_MEMRESERVE_TABLE_GUID;
	76	efi_status_t status;
	77
eff89628 AB	78	if (IS_ENABLED(CONFIG_ARM))
	79	return;
	80
b844470f AB	81	status = efi_call_early(allocate_pool, EFI_LOADER_DATA, sizeof(*rsv),
	82	(void **)&rsv);
	83	if (status != EFI_SUCCESS) {
	84	pr_efi_err(sys_table_arg, "Failed to allocate memreserve entry!\n");
	85	return;
	86	}
	87
	88	rsv->next = 0;
	89	rsv->base = 0;
	90	rsv->size = 0;
	91
	92	status = efi_call_early(install_configuration_table,
	93	&memreserve_table_guid,
	94	rsv);
	95	if (status != EFI_SUCCESS)
	96	pr_efi_err(sys_table_arg, "Failed to install memreserve config table!\n");
	97	}
	98
	99
3c7f2550 MS	100	/*
	101	* This function handles the architcture specific differences between arm and
	102	* arm64 regarding where the kernel image must be loaded and any memory that
	103	* must be reserved. On failure it is required to free all
	104	* all allocations it has made.
	105	*/
bd669475 AB	106	efi_status_t handle_kernel_image(efi_system_table_t *sys_table,
	107	unsigned long *image_addr,
	108	unsigned long *image_size,
	109	unsigned long *reserve_addr,
	110	unsigned long *reserve_size,
	111	unsigned long dram_base,
	112	efi_loaded_image_t *image);
3c7f2550 MS	113	/*
	114	* EFI entry point for the arm/arm64 EFI stubs. This is the entrypoint
	115	* that is described in the PE/COFF header. Most of the code is the same
	116	* for both archictectures, with the arch-specific code provided in the
	117	* handle_kernel_image() function.
	118	*/
ddeeefe2	119	unsigned long efi_entry(void handle, efi_system_table_t sys_table,
3c7f2550 MS	120	unsigned long *image_addr)
	121	{
	122	efi_loaded_image_t *image;
	123	efi_status_t status;
	124	unsigned long image_size = 0;
	125	unsigned long dram_base;
	126	/* addr/point and size pairs for memory management*/
	127	unsigned long initrd_addr;
	128	u64 initrd_size = 0;
345c736e	129	unsigned long fdt_addr = 0; /* Original DTB */
a643375f	130	unsigned long fdt_size = 0;
3c7f2550 MS	131	char *cmdline_ptr = NULL;
	132	int cmdline_size = 0;
	133	unsigned long new_fdt_addr;
	134	efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID;
	135	unsigned long reserve_addr = 0;
	136	unsigned long reserve_size = 0;
de8cb458	137	enum efi_secureboot_mode secure_boot;
f0827e18	138	struct screen_info *si;
3c7f2550 MS	139
	140	/* Check if we were booted by the EFI firmware */
	141	if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
	142	goto fail;
	143
b9d6769b AB	144	status = check_platform_features(sys_table);
	145	if (status != EFI_SUCCESS)
	146	goto fail;
	147
3c7f2550 MS	148	/*
	149	* Get a handle to the loaded image protocol. This is used to get
	150	* information about the running image, such as size and the command
	151	* line.
	152	*/
	153	status = sys_table->boottime->handle_protocol(handle,
	154	&loaded_image_proto, (void *)&image);
	155	if (status != EFI_SUCCESS) {
	156	pr_efi_err(sys_table, "Failed to get loaded image protocol\n");
	157	goto fail;
	158	}
	159
	160	dram_base = get_dram_base(sys_table);
	161	if (dram_base == EFI_ERROR) {
	162	pr_efi_err(sys_table, "Failed to find DRAM base\n");
	163	goto fail;
	164	}
3c7f2550 MS	165
	166	/*
	167	* Get the command line from EFI, using the LOADED_IMAGE
	168	* protocol. We are going to copy the command line into the
	169	* device tree, so this can be allocated anywhere.
	170	*/
	171	cmdline_ptr = efi_convert_cmdline(sys_table, image, &cmdline_size);
	172	if (!cmdline_ptr) {
	173	pr_efi_err(sys_table, "getting command line via LOADED_IMAGE_PROTOCOL\n");
2b5fe07a AB	174	goto fail;
	175	}
	176
eeff7d63 AB	177	if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) \|\|
	178	IS_ENABLED(CONFIG_CMDLINE_FORCE) \|\|
	179	cmdline_size == 0)
	180	efi_parse_options(CONFIG_CMDLINE);
	181
	182	if (!IS_ENABLED(CONFIG_CMDLINE_FORCE) && cmdline_size > 0)
	183	efi_parse_options(cmdline_ptr);
	184
	185	pr_efi(sys_table, "Booting Linux Kernel...\n");
	186
f0827e18 AB	187	si = setup_graphics(sys_table);
f0827e18 AB	188
2b5fe07a AB	189	status = handle_kernel_image(sys_table, image_addr, &image_size,
	190	&reserve_addr,
	191	&reserve_size,
	192	dram_base, image);
	193	if (status != EFI_SUCCESS) {
	194	pr_efi_err(sys_table, "Failed to relocate kernel\n");
	195	goto fail_free_cmdline;
3c7f2550 MS	196	}
3c7f2550 MS	197
ccc829ba MG	198	/* Ask the firmware to clear memory on unclean shutdown */
	199	efi_enable_reset_attack_mitigation(sys_table);
	200
73a64925	201	secure_boot = efi_get_secureboot(sys_table);
73a64925	202
345c736e	203	/*
de8cb458 DH	204	* Unauthenticated device tree data is a security hazard, so ignore
	205	* 'dtb=' unless UEFI Secure Boot is disabled. We assume that secure
	206	* boot is enabled if we can't determine its state.
345c736e	207	*/
3d7ee348 AB	208	if (!IS_ENABLED(CONFIG_EFI_ARMSTUB_DTB_LOADER) \|\|
	209	secure_boot != efi_secureboot_mode_disabled) {
	210	if (strstr(cmdline_ptr, "dtb="))
	211	pr_efi(sys_table, "Ignoring DTB from command line.\n");
345c736e	212	} else {
3c7f2550 MS	213	status = handle_cmdline_files(sys_table, image, cmdline_ptr,
3c7f2550 MS	214	"dtb=",
a643375f	215	~0UL, &fdt_addr, &fdt_size);
3c7f2550 MS	216
	217	if (status != EFI_SUCCESS) {
	218	pr_efi_err(sys_table, "Failed to load device tree!\n");
2b5fe07a	219	goto fail_free_image;
3c7f2550 MS	220	}
3c7f2550 MS	221	}
0bcaa904 MR	222
	223	if (fdt_addr) {
	224	pr_efi(sys_table, "Using DTB from command line\n");
	225	} else {
345c736e	226	/* Look for a device tree configuration table entry. */
a643375f	227	fdt_addr = (uintptr_t)get_fdt(sys_table, &fdt_size);
0bcaa904 MR	228	if (fdt_addr)
	229	pr_efi(sys_table, "Using DTB from configuration table\n");
	230	}
	231
	232	if (!fdt_addr)
	233	pr_efi(sys_table, "Generating empty DTB\n");
3c7f2550	234
138728dd AB	235	status = handle_cmdline_files(sys_table, image, cmdline_ptr, "initrd=",
	236	efi_get_max_initrd_addr(dram_base,
	237	*image_addr),
3c7f2550 MS	238	(unsigned long *)&initrd_addr,
	239	(unsigned long *)&initrd_size);
	240	if (status != EFI_SUCCESS)
	241	pr_efi_err(sys_table, "Failed initrd from command line!\n");
	242
568bc4e8 AB	243	efi_random_get_seed(sys_table);
568bc4e8 AB	244
38fb6652 AB	245	/* hibernation expects the runtime regions to stay in the same place */
38fb6652 AB	246	if (!IS_ENABLED(CONFIG_HIBERNATION) && !nokaslr()) {
e69176d6 AB	247	/*
	248	* Randomize the base of the UEFI runtime services region.
	249	* Preserve the 2 MB alignment of the region by taking a
	250	* shift of 21 bit positions into account when scaling
	251	* the headroom value using a 32-bit random value.
	252	*/
197decef AB	253	static const u64 headroom = EFI_RT_VIRTUAL_LIMIT -
	254	EFI_RT_VIRTUAL_BASE -
	255	EFI_RT_VIRTUAL_SIZE;
e69176d6 AB	256	u32 rnd;
	257
	258	status = efi_get_random_bytes(sys_table, sizeof(rnd),
	259	(u8 *)&rnd);
	260	if (status == EFI_SUCCESS) {
	261	virtmap_base = EFI_RT_VIRTUAL_BASE +
	262	(((headroom >> 21) * rnd) >> (32 - 21));
	263	}
	264	}
	265
b844470f AB	266	install_memreserve_table(sys_table);
b844470f AB	267
3c7f2550 MS	268	new_fdt_addr = fdt_addr;
3c7f2550 MS	269	status = allocate_new_fdt_and_exit_boot(sys_table, handle,
138728dd	270	&new_fdt_addr, efi_get_max_fdt_addr(dram_base),
3c7f2550 MS	271	initrd_addr, initrd_size, cmdline_ptr,
	272	fdt_addr, fdt_size);
	273
	274	/*
	275	* If all went well, we need to return the FDT address to the
	276	* calling function so it can be passed to kernel as part of
	277	* the kernel boot protocol.
	278	*/
	279	if (status == EFI_SUCCESS)
	280	return new_fdt_addr;
	281
	282	pr_efi_err(sys_table, "Failed to update FDT and exit boot services\n");
	283
	284	efi_free(sys_table, initrd_size, initrd_addr);
	285	efi_free(sys_table, fdt_size, fdt_addr);
	286
3c7f2550 MS	287	fail_free_image:
	288	efi_free(sys_table, image_size, *image_addr);
	289	efi_free(sys_table, reserve_size, reserve_addr);
2b5fe07a	290	fail_free_cmdline:
f0827e18	291	free_screen_info(sys_table, si);
2b5fe07a	292	efi_free(sys_table, cmdline_size, (unsigned long)cmdline_ptr);
3c7f2550 MS	293	fail:
	294	return EFI_ERROR;
	295	}
f3cdfd23	296
0ce3cc00 AB	297	static int cmp_mem_desc(const void l, const void r)
	298	{
	299	const efi_memory_desc_t left = l, right = r;
	300
	301	return (left->phys_addr > right->phys_addr) ? 1 : -1;
	302	}
	303
	304	/*
	305	* Returns whether region @left ends exactly where region @right starts,
	306	* or false if either argument is NULL.
	307	*/
	308	static bool regions_are_adjacent(efi_memory_desc_t *left,
	309	efi_memory_desc_t *right)
	310	{
	311	u64 left_end;
	312
	313	if (left == NULL \|\| right == NULL)
	314	return false;
	315
	316	left_end = left->phys_addr + left->num_pages * EFI_PAGE_SIZE;
	317
	318	return left_end == right->phys_addr;
	319	}
	320
	321	/*
	322	* Returns whether region @left and region @right have compatible memory type
	323	* mapping attributes, and are both EFI_MEMORY_RUNTIME regions.
	324	*/
	325	static bool regions_have_compatible_memory_type_attrs(efi_memory_desc_t *left,
	326	efi_memory_desc_t *right)
	327	{
	328	static const u64 mem_type_mask = EFI_MEMORY_WB \| EFI_MEMORY_WT \|
	329	EFI_MEMORY_WC \| EFI_MEMORY_UC \|
	330	EFI_MEMORY_RUNTIME;
	331
	332	return ((left->attribute ^ right->attribute) & mem_type_mask) == 0;
	333	}
	334
f3cdfd23 AB	335	/*
	336	* efi_get_virtmap() - create a virtual mapping for the EFI memory map
	337	*
	338	* This function populates the virt_addr fields of all memory region descriptors
	339	* in @memory_map whose EFI_MEMORY_RUNTIME attribute is set. Those descriptors
	340	* are also copied to @runtime_map, and their total count is returned in @count.
	341	*/
	342	void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size,
	343	unsigned long desc_size, efi_memory_desc_t *runtime_map,
	344	int *count)
	345	{
e69176d6	346	u64 efi_virt_base = virtmap_base;
0ce3cc00	347	efi_memory_desc_t in, prev = NULL, *out = runtime_map;
f3cdfd23 AB	348	int l;
f3cdfd23 AB	349
0ce3cc00 AB	350	/*
	351	* To work around potential issues with the Properties Table feature
	352	* introduced in UEFI 2.5, which may split PE/COFF executable images
	353	* in memory into several RuntimeServicesCode and RuntimeServicesData
	354	* regions, we need to preserve the relative offsets between adjacent
	355	* EFI_MEMORY_RUNTIME regions with the same memory type attributes.
	356	* The easiest way to find adjacent regions is to sort the memory map
	357	* before traversing it.
	358	*/
29f9007b AB	359	if (IS_ENABLED(CONFIG_ARM64))
	360	sort(memory_map, map_size / desc_size, desc_size, cmp_mem_desc,
	361	NULL);
0ce3cc00 AB	362
0ce3cc00 AB	363	for (l = 0; l < map_size; l += desc_size, prev = in) {
f3cdfd23 AB	364	u64 paddr, size;
f3cdfd23 AB	365
0ce3cc00	366	in = (void *)memory_map + l;
f3cdfd23 AB	367	if (!(in->attribute & EFI_MEMORY_RUNTIME))
	368	continue;
	369
0ce3cc00 AB	370	paddr = in->phys_addr;
	371	size = in->num_pages * EFI_PAGE_SIZE;
	372
f3cdfd23 AB	373	/*
	374	* Make the mapping compatible with 64k pages: this allows
	375	* a 4k page size kernel to kexec a 64k page size kernel and
	376	* vice versa.
	377	*/
29f9007b AB	378	if ((IS_ENABLED(CONFIG_ARM64) &&
29f9007b AB	379	!regions_are_adjacent(prev, in)) \|\|
0ce3cc00 AB	380	!regions_have_compatible_memory_type_attrs(prev, in)) {
	381
	382	paddr = round_down(in->phys_addr, SZ_64K);
	383	size += in->phys_addr - paddr;
	384
	385	/*
	386	* Avoid wasting memory on PTEs by choosing a virtual
	387	* base that is compatible with section mappings if this
	388	* region has the appropriate size and physical
	389	* alignment. (Sections are 2 MB on 4k granule kernels)
	390	*/
	391	if (IS_ALIGNED(in->phys_addr, SZ_2M) && size >= SZ_2M)
	392	efi_virt_base = round_up(efi_virt_base, SZ_2M);
	393	else
	394	efi_virt_base = round_up(efi_virt_base, SZ_64K);
	395	}
f3cdfd23 AB	396
	397	in->virt_addr = efi_virt_base + in->phys_addr - paddr;
	398	efi_virt_base += size;
	399
	400	memcpy(out, in, desc_size);
	401	out = (void *)out + desc_size;
	402	++*count;
	403	}
	404	}