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// SPDX-License-Identifier: GPL-2.0
#include <linux/efi.h>
#include <asm/efi.h>
#include "efistub.h"
/**
* efi_get_memory_map() - get memory map
* @map: pointer to memory map pointer to which to assign the
* newly allocated memory map
* @install_cfg_tbl: whether or not to install the boot memory map as a
* configuration table
*
* Retrieve the UEFI memory map. The allocated memory leaves room for
* up to EFI_MMAP_NR_SLACK_SLOTS additional memory map entries.
*
* Return: status code
*/
efi_status_t efi_get_memory_map(struct efi_boot_memmap **map,
bool install_cfg_tbl)
{
int memtype = install_cfg_tbl ? EFI_ACPI_RECLAIM_MEMORY
: EFI_LOADER_DATA;
efi_guid_t tbl_guid = LINUX_EFI_BOOT_MEMMAP_GUID;
struct efi_boot_memmap *m, tmp;
efi_status_t status;
unsigned long size;
tmp.map_size = 0;
status = efi_bs_call(get_memory_map, &tmp.map_size, NULL, &tmp.map_key,
&tmp.desc_size, &tmp.desc_ver);
if (status != EFI_BUFFER_TOO_SMALL)
return EFI_LOAD_ERROR;
size = tmp.map_size + tmp.desc_size * EFI_MMAP_NR_SLACK_SLOTS;
status = efi_bs_call(allocate_pool, memtype, sizeof(*m) + size,
(void **)&m);
if (status != EFI_SUCCESS)
return status;
if (install_cfg_tbl) {
/*
* Installing a configuration table might allocate memory, and
* this may modify the memory map. This means we should install
* the configuration table first, and re-install or delete it
* as needed.
*/
status = efi_bs_call(install_configuration_table, &tbl_guid, m);
if (status != EFI_SUCCESS)
goto free_map;
}
m->buff_size = m->map_size = size;
status = efi_bs_call(get_memory_map, &m->map_size, m->map, &m->map_key,
&m->desc_size, &m->desc_ver);
if (status != EFI_SUCCESS)
goto uninstall_table;
*map = m;
return EFI_SUCCESS;
uninstall_table:
if (install_cfg_tbl)
efi_bs_call(install_configuration_table, &tbl_guid, NULL);
free_map:
efi_bs_call(free_pool, m);
return status;
}
/**
* efi_allocate_pages() - Allocate memory pages
* @size: minimum number of bytes to allocate
* @addr: On return the address of the first allocated page. The first
* allocated page has alignment EFI_ALLOC_ALIGN which is an
* architecture dependent multiple of the page size.
* @max: the address that the last allocated memory page shall not
* exceed
*
* Allocate pages as EFI_LOADER_DATA. The allocated pages are aligned according
* to EFI_ALLOC_ALIGN. The last allocated page will not exceed the address
* given by @max.
*
* Return: status code
*/
efi_status_t efi_allocate_pages(unsigned long size, unsigned long *addr,
unsigned long max)
{
efi_physical_addr_t alloc_addr;
efi_status_t status;
max = min(max, EFI_ALLOC_LIMIT);
if (EFI_ALLOC_ALIGN > EFI_PAGE_SIZE)
return efi_allocate_pages_aligned(size, addr, max,
EFI_ALLOC_ALIGN,
EFI_LOADER_DATA);
alloc_addr = ALIGN_DOWN(max + 1, EFI_ALLOC_ALIGN) - 1;
status = efi_bs_call(allocate_pages, EFI_ALLOCATE_MAX_ADDRESS,
EFI_LOADER_DATA, DIV_ROUND_UP(size, EFI_PAGE_SIZE),
&alloc_addr);
if (status != EFI_SUCCESS)
return status;
*addr = alloc_addr;
return EFI_SUCCESS;
}
/**
* efi_free() - free memory pages
* @size: size of the memory area to free in bytes
* @addr: start of the memory area to free (must be EFI_PAGE_SIZE
* aligned)
*
* @size is rounded up to a multiple of EFI_ALLOC_ALIGN which is an
* architecture specific multiple of EFI_PAGE_SIZE. So this function should
* only be used to return pages allocated with efi_allocate_pages() or
* efi_low_alloc_above().
*/
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);
}
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