Commit f57db62c authored by Ard Biesheuvel's avatar Ard Biesheuvel
Browse files

efi/libstub: Move memory map handling and allocation routines to mem.c 



Create a new source file mem.c to keep the routines involved in memory
allocation and deallocation and manipulation of the EFI memory map.

Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
parent 184d7e0d

drivers/firmware/efi/libstub/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -40,7 +40,7 @@ OBJECT_FILES_NON_STANDARD := y 
KCOV_INSTRUMENT			:= n



lib-y				:= efi-stub-helper.o gop.o secureboot.o tpm.o \

				   random.o pci.o

				   mem.o random.o pci.o



# include the stub's generic dependencies from lib/ when building for ARM/arm64

arm-deps-y := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c

drivers/firmware/efi/libstub/efi-stub-helper.c

+0 −313
Original line number Diff line number Diff line
@@ -53,8 +53,6 @@ bool __pure __efi_soft_reserve_enabled(void) 
	return !efi_nosoftreserve;

}



#define EFI_MMAP_NR_SLACK_SLOTS	8



struct file_info {

	efi_file_handle_t *handle;

	u64 size;
@@ -77,64 +75,6 @@ void efi_printk(char *str) 
	}

}



static inline bool mmap_has_headroom(unsigned long buff_size,

				     unsigned long map_size,

				     unsigned long desc_size)

{

	unsigned long slack = buff_size - map_size;



	return slack / desc_size >= EFI_MMAP_NR_SLACK_SLOTS;

}



efi_status_t efi_get_memory_map(struct efi_boot_memmap *map)

{

	efi_memory_desc_t *m = NULL;

	efi_status_t status;

	unsigned long key;

	u32 desc_version;



	*map->desc_size =	sizeof(*m);

	*map->map_size =	*map->desc_size * 32;

	*map->buff_size =	*map->map_size;

again:

	status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,

			     *map->map_size, (void **)&m);

	if (status != EFI_SUCCESS)

		goto fail;



	*map->desc_size = 0;

	key = 0;

	status = efi_bs_call(get_memory_map, map->map_size, m,

			     &key, map->desc_size, &desc_version);

	if (status == EFI_BUFFER_TOO_SMALL ||

	    !mmap_has_headroom(*map->buff_size, *map->map_size,

			       *map->desc_size)) {

		efi_bs_call(free_pool, m);

		/*

		 * Make sure there is some entries of headroom so that the

		 * buffer can be reused for a new map after allocations are

		 * no longer permitted.  Its unlikely that the map will grow to

		 * exceed this headroom once we are ready to trigger

		 * ExitBootServices()

		 */

		*map->map_size += *map->desc_size * EFI_MMAP_NR_SLACK_SLOTS;

		*map->buff_size = *map->map_size;

		goto again;

	}



	if (status != EFI_SUCCESS)

		efi_bs_call(free_pool, m);



	if (map->key_ptr && status == EFI_SUCCESS)

		*map->key_ptr = key;

	if (map->desc_ver && status == EFI_SUCCESS)

		*map->desc_ver = desc_version;



fail:

	*map->map = m;

	return status;

}





unsigned long get_dram_base(void)

{
@@ -170,192 +110,6 @@ unsigned long get_dram_base(void) 
	return membase;

}



/*

 * Allocate at the highest possible address that is not above 'max'.

 */

efi_status_t efi_high_alloc(unsigned long size, unsigned long align,

			    unsigned long *addr, unsigned long max)

{

	unsigned long map_size, desc_size, buff_size;

	efi_memory_desc_t *map;

	efi_status_t status;

	unsigned long nr_pages;

	u64 max_addr = 0;

	int i;

	struct efi_boot_memmap boot_map;



	boot_map.map =		&map;

	boot_map.map_size =	&map_size;

	boot_map.desc_size =	&desc_size;

	boot_map.desc_ver =	NULL;

	boot_map.key_ptr =	NULL;

	boot_map.buff_size =	&buff_size;



	status = efi_get_memory_map(&boot_map);

	if (status != EFI_SUCCESS)

		goto fail;



	/*

	 * Enforce minimum alignment that EFI or Linux requires when

	 * requesting a specific address.  We are doing page-based (or

	 * larger) allocations, and both the address and size must meet

	 * alignment constraints.

	 */

	if (align < EFI_ALLOC_ALIGN)

		align = EFI_ALLOC_ALIGN;



	size = round_up(size, EFI_ALLOC_ALIGN);

	nr_pages = size / EFI_PAGE_SIZE;

again:

	for (i = 0; i < map_size / desc_size; i++) {

		efi_memory_desc_t *desc;

		unsigned long m = (unsigned long)map;

		u64 start, end;



		desc = efi_early_memdesc_ptr(m, desc_size, i);

		if (desc->type != EFI_CONVENTIONAL_MEMORY)

			continue;



		if (efi_soft_reserve_enabled() &&

		    (desc->attribute & EFI_MEMORY_SP))

			continue;



		if (desc->num_pages < nr_pages)

			continue;



		start = desc->phys_addr;

		end = start + desc->num_pages * EFI_PAGE_SIZE;



		if (end > max)

			end = max;



		if ((start + size) > end)

			continue;



		if (round_down(end - size, align) < start)

			continue;



		start = round_down(end - size, align);



		/*

		 * Don't allocate at 0x0. It will confuse code that

		 * checks pointers against NULL.

		 */

		if (start == 0x0)

			continue;



		if (start > max_addr)

			max_addr = start;

	}



	if (!max_addr)

		status = EFI_NOT_FOUND;

	else {

		status = efi_bs_call(allocate_pages, EFI_ALLOCATE_ADDRESS,

				     EFI_LOADER_DATA, nr_pages, &max_addr);

		if (status != EFI_SUCCESS) {

			max = max_addr;

			max_addr = 0;

			goto again;

		}



		*addr = max_addr;

	}



	efi_bs_call(free_pool, map);

fail:

	return status;

}



/*

 * Allocate at the lowest possible address that is not below 'min'.

 */

efi_status_t efi_low_alloc_above(unsigned long size, unsigned long align,

				 unsigned long *addr, unsigned long min)

{

	unsigned long map_size, desc_size, buff_size;

	efi_memory_desc_t *map;

	efi_status_t status;

	unsigned long nr_pages;

	int i;

	struct efi_boot_memmap boot_map;



	boot_map.map =		&map;

	boot_map.map_size =	&map_size;

	boot_map.desc_size =	&desc_size;

	boot_map.desc_ver =	NULL;

	boot_map.key_ptr =	NULL;

	boot_map.buff_size =	&buff_size;



	status = efi_get_memory_map(&boot_map);

	if (status != EFI_SUCCESS)

		goto fail;



	/*

	 * Enforce minimum alignment that EFI or Linux requires when

	 * requesting a specific address.  We are doing page-based (or

	 * larger) allocations, and both the address and size must meet

	 * alignment constraints.

	 */

	if (align < EFI_ALLOC_ALIGN)

		align = EFI_ALLOC_ALIGN;



	size = round_up(size, EFI_ALLOC_ALIGN);

	nr_pages = size / EFI_PAGE_SIZE;

	for (i = 0; i < map_size / desc_size; i++) {

		efi_memory_desc_t *desc;

		unsigned long m = (unsigned long)map;

		u64 start, end;



		desc = efi_early_memdesc_ptr(m, desc_size, i);



		if (desc->type != EFI_CONVENTIONAL_MEMORY)

			continue;



		if (efi_soft_reserve_enabled() &&

		    (desc->attribute & EFI_MEMORY_SP))

			continue;



		if (desc->num_pages < nr_pages)

			continue;



		start = desc->phys_addr;

		end = start + desc->num_pages * EFI_PAGE_SIZE;



		if (start < min)

			start = min;



		start = round_up(start, align);

		if ((start + size) > end)

			continue;



		status = efi_bs_call(allocate_pages, EFI_ALLOCATE_ADDRESS,

				     EFI_LOADER_DATA, nr_pages, &start);

		if (status == EFI_SUCCESS) {

			*addr = start;

			break;

		}

	}



	if (i == map_size / desc_size)

		status = EFI_NOT_FOUND;



	efi_bs_call(free_pool, map);

fail:

	return status;

}



void efi_free(unsigned long size, unsigned long addr)

{

	unsigned long nr_pages;



	if (!size)

		return;



	nr_pages = round_up(size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE;

	efi_bs_call(free_pages, addr, nr_pages);

}



static efi_status_t efi_file_size(void *__fh, efi_char16_t *filename_16,

				  void **handle, u64 *file_sz)

{
@@ -695,73 +449,6 @@ efi_status_t handle_cmdline_files(efi_loaded_image_t *image, 


	return status;

}

/*

 * Relocate a kernel image, either compressed or uncompressed.

 * In the ARM64 case, all kernel images are currently

 * uncompressed, and as such when we relocate it we need to

 * allocate additional space for the BSS segment. Any low

 * memory that this function should avoid needs to be

 * unavailable in the EFI memory map, as if the preferred

 * address is not available the lowest available address will

 * be used.

 */

efi_status_t efi_relocate_kernel(unsigned long *image_addr,

				 unsigned long image_size,

				 unsigned long alloc_size,

				 unsigned long preferred_addr,

				 unsigned long alignment,

				 unsigned long min_addr)

{

	unsigned long cur_image_addr;

	unsigned long new_addr = 0;

	efi_status_t status;

	unsigned long nr_pages;

	efi_physical_addr_t efi_addr = preferred_addr;



	if (!image_addr || !image_size || !alloc_size)

		return EFI_INVALID_PARAMETER;

	if (alloc_size < image_size)

		return EFI_INVALID_PARAMETER;



	cur_image_addr = *image_addr;



	/*

	 * The EFI firmware loader could have placed the kernel image

	 * anywhere in memory, but the kernel has restrictions on the

	 * max physical address it can run at.  Some architectures

	 * also have a prefered address, so first try to relocate

	 * to the preferred address.  If that fails, allocate as low

	 * as possible while respecting the required alignment.

	 */

	nr_pages = round_up(alloc_size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE;

	status = efi_bs_call(allocate_pages, EFI_ALLOCATE_ADDRESS,

			     EFI_LOADER_DATA, nr_pages, &efi_addr);

	new_addr = efi_addr;

	/*

	 * If preferred address allocation failed allocate as low as

	 * possible.

	 */

	if (status != EFI_SUCCESS) {

		status = efi_low_alloc_above(alloc_size, alignment, &new_addr,

					     min_addr);

	}

	if (status != EFI_SUCCESS) {

		pr_efi_err("Failed to allocate usable memory for kernel.\n");

		return status;

	}



	/*

	 * We know source/dest won't overlap since both memory ranges

	 * have been allocated by UEFI, so we can safely use memcpy.

	 */

	memcpy((void *)new_addr, (void *)cur_image_addr, image_size);



	/* Return the new address of the relocated image. */

	*image_addr = new_addr;



	return status;

}



/*

 * Get the number of UTF-8 bytes corresponding to an UTF-16 character.

 * This overestimates for surrogates, but that is okay.

drivers/firmware/efi/libstub/mem.c

0 → 100644
+319 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0



#include <linux/efi.h>

#include <asm/efi.h>



#include "efistub.h"



#define EFI_MMAP_NR_SLACK_SLOTS	8



static inline bool mmap_has_headroom(unsigned long buff_size,

				     unsigned long map_size,

				     unsigned long desc_size)

{

	unsigned long slack = buff_size - map_size;



	return slack / desc_size >= EFI_MMAP_NR_SLACK_SLOTS;

}



efi_status_t efi_get_memory_map(struct efi_boot_memmap *map)

{

	efi_memory_desc_t *m = NULL;

	efi_status_t status;

	unsigned long key;

	u32 desc_version;



	*map->desc_size =	sizeof(*m);

	*map->map_size =	*map->desc_size * 32;

	*map->buff_size =	*map->map_size;

again:

	status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,

			     *map->map_size, (void **)&m);

	if (status != EFI_SUCCESS)

		goto fail;



	*map->desc_size = 0;

	key = 0;

	status = efi_bs_call(get_memory_map, map->map_size, m,

			     &key, map->desc_size, &desc_version);

	if (status == EFI_BUFFER_TOO_SMALL ||

	    !mmap_has_headroom(*map->buff_size, *map->map_size,

			       *map->desc_size)) {

		efi_bs_call(free_pool, m);

		/*

		 * Make sure there is some entries of headroom so that the

		 * buffer can be reused for a new map after allocations are

		 * no longer permitted.  Its unlikely that the map will grow to

		 * exceed this headroom once we are ready to trigger

		 * ExitBootServices()

		 */

		*map->map_size += *map->desc_size * EFI_MMAP_NR_SLACK_SLOTS;

		*map->buff_size = *map->map_size;

		goto again;

	}



	if (status != EFI_SUCCESS)

		efi_bs_call(free_pool, m);



	if (map->key_ptr && status == EFI_SUCCESS)

		*map->key_ptr = key;

	if (map->desc_ver && status == EFI_SUCCESS)

		*map->desc_ver = desc_version;



fail:

	*map->map = m;

	return status;

}



/*

 * Allocate at the highest possible address that is not above 'max'.

 */

efi_status_t efi_high_alloc(unsigned long size, unsigned long align,

			    unsigned long *addr, unsigned long max)

{

	unsigned long map_size, desc_size, buff_size;

	efi_memory_desc_t *map;

	efi_status_t status;

	unsigned long nr_pages;

	u64 max_addr = 0;

	int i;

	struct efi_boot_memmap boot_map;



	boot_map.map =		&map;

	boot_map.map_size =	&map_size;

	boot_map.desc_size =	&desc_size;

	boot_map.desc_ver =	NULL;

	boot_map.key_ptr =	NULL;

	boot_map.buff_size =	&buff_size;



	status = efi_get_memory_map(&boot_map);

	if (status != EFI_SUCCESS)

		goto fail;



	/*

	 * Enforce minimum alignment that EFI or Linux requires when

	 * requesting a specific address.  We are doing page-based (or

	 * larger) allocations, and both the address and size must meet

	 * alignment constraints.

	 */

	if (align < EFI_ALLOC_ALIGN)

		align = EFI_ALLOC_ALIGN;



	size = round_up(size, EFI_ALLOC_ALIGN);

	nr_pages = size / EFI_PAGE_SIZE;

again:

	for (i = 0; i < map_size / desc_size; i++) {

		efi_memory_desc_t *desc;

		unsigned long m = (unsigned long)map;

		u64 start, end;



		desc = efi_early_memdesc_ptr(m, desc_size, i);

		if (desc->type != EFI_CONVENTIONAL_MEMORY)

			continue;



		if (efi_soft_reserve_enabled() &&

		    (desc->attribute & EFI_MEMORY_SP))

			continue;



		if (desc->num_pages < nr_pages)

			continue;



		start = desc->phys_addr;

		end = start + desc->num_pages * EFI_PAGE_SIZE;



		if (end > max)

			end = max;



		if ((start + size) > end)

			continue;



		if (round_down(end - size, align) < start)

			continue;



		start = round_down(end - size, align);



		/*

		 * Don't allocate at 0x0. It will confuse code that

		 * checks pointers against NULL.

		 */

		if (start == 0x0)

			continue;



		if (start > max_addr)

			max_addr = start;

	}



	if (!max_addr)

		status = EFI_NOT_FOUND;

	else {

		status = efi_bs_call(allocate_pages, EFI_ALLOCATE_ADDRESS,

				     EFI_LOADER_DATA, nr_pages, &max_addr);

		if (status != EFI_SUCCESS) {

			max = max_addr;

			max_addr = 0;

			goto again;

		}



		*addr = max_addr;

	}



	efi_bs_call(free_pool, map);

fail:

	return status;

}



/*

 * Allocate at the lowest possible address that is not below 'min'.

 */

efi_status_t efi_low_alloc_above(unsigned long size, unsigned long align,

				 unsigned long *addr, unsigned long min)

{

	unsigned long map_size, desc_size, buff_size;

	efi_memory_desc_t *map;

	efi_status_t status;

	unsigned long nr_pages;

	int i;

	struct efi_boot_memmap boot_map;



	boot_map.map		= &map;

	boot_map.map_size	= &map_size;

	boot_map.desc_size	= &desc_size;

	boot_map.desc_ver	= NULL;

	boot_map.key_ptr	= NULL;

	boot_map.buff_size	= &buff_size;



	status = efi_get_memory_map(&boot_map);

	if (status != EFI_SUCCESS)

		goto fail;



	/*

	 * Enforce minimum alignment that EFI or Linux requires when

	 * requesting a specific address.  We are doing page-based (or

	 * larger) allocations, and both the address and size must meet

	 * alignment constraints.

	 */

	if (align < EFI_ALLOC_ALIGN)

		align = EFI_ALLOC_ALIGN;



	size = round_up(size, EFI_ALLOC_ALIGN);

	nr_pages = size / EFI_PAGE_SIZE;

	for (i = 0; i < map_size / desc_size; i++) {

		efi_memory_desc_t *desc;

		unsigned long m = (unsigned long)map;

		u64 start, end;



		desc = efi_early_memdesc_ptr(m, desc_size, i);



		if (desc->type != EFI_CONVENTIONAL_MEMORY)

			continue;



		if (efi_soft_reserve_enabled() &&

		    (desc->attribute & EFI_MEMORY_SP))

			continue;



		if (desc->num_pages < nr_pages)

			continue;



		start = desc->phys_addr;

		end = start + desc->num_pages * EFI_PAGE_SIZE;



		if (start < min)

			start = min;



		start = round_up(start, align);

		if ((start + size) > end)

			continue;



		status = efi_bs_call(allocate_pages, EFI_ALLOCATE_ADDRESS,

				     EFI_LOADER_DATA, nr_pages, &start);

		if (status == EFI_SUCCESS) {

			*addr = start;

			break;

		}

	}



	if (i == map_size / desc_size)

		status = EFI_NOT_FOUND;



	efi_bs_call(free_pool, map);

fail:

	return status;

}



void efi_free(unsigned long size, unsigned long addr)

{

	unsigned long nr_pages;



	if (!size)

		return;



	nr_pages = round_up(size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE;

	efi_bs_call(free_pages, addr, nr_pages);

}



/*

 * Relocate a kernel image, either compressed or uncompressed.

 * In the ARM64 case, all kernel images are currently

 * uncompressed, and as such when we relocate it we need to

 * allocate additional space for the BSS segment. Any low

 * memory that this function should avoid needs to be

 * unavailable in the EFI memory map, as if the preferred

 * address is not available the lowest available address will

 * be used.

 */

efi_status_t efi_relocate_kernel(unsigned long *image_addr,

				 unsigned long image_size,

				 unsigned long alloc_size,

				 unsigned long preferred_addr,

				 unsigned long alignment,

				 unsigned long min_addr)

{

	unsigned long cur_image_addr;

	unsigned long new_addr = 0;

	efi_status_t status;

	unsigned long nr_pages;

	efi_physical_addr_t efi_addr = preferred_addr;



	if (!image_addr || !image_size || !alloc_size)

		return EFI_INVALID_PARAMETER;

	if (alloc_size < image_size)

		return EFI_INVALID_PARAMETER;



	cur_image_addr = *image_addr;



	/*

	 * The EFI firmware loader could have placed the kernel image

	 * anywhere in memory, but the kernel has restrictions on the

	 * max physical address it can run at.  Some architectures

	 * also have a prefered address, so first try to relocate

	 * to the preferred address.  If that fails, allocate as low

	 * as possible while respecting the required alignment.

	 */

	nr_pages = round_up(alloc_size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE;

	status = efi_bs_call(allocate_pages, EFI_ALLOCATE_ADDRESS,

			     EFI_LOADER_DATA, nr_pages, &efi_addr);

	new_addr = efi_addr;

	/*

	 * If preferred address allocation failed allocate as low as

	 * possible.

	 */

	if (status != EFI_SUCCESS) {

		status = efi_low_alloc_above(alloc_size, alignment, &new_addr,

					     min_addr);

	}

	if (status != EFI_SUCCESS) {

		pr_efi_err("Failed to allocate usable memory for kernel.\n");

		return status;

	}



	/*

	 * We know source/dest won't overlap since both memory ranges

	 * have been allocated by UEFI, so we can safely use memcpy.

	 */

	memcpy((void *)new_addr, (void *)cur_image_addr, image_size);



	/* Return the new address of the relocated image. */

	*image_addr = new_addr;



	return status;

}