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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)
{
struct efi_boot_memmap tmp, *m __free(efi_pool) = NULL;
int memtype = install_cfg_tbl ? EFI_ACPI_RECLAIM_MEMORY
: EFI_LOADER_DATA;
efi_guid_t tbl_guid = LINUX_EFI_BOOT_MEMMAP_GUID;
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)
return status;
}
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) {
if (install_cfg_tbl)
efi_bs_call(install_configuration_table, &tbl_guid, NULL);
return status;
}
*map = no_free_ptr(m);
return EFI_SUCCESS;
}
/**
* 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);
}
/**
* efi_low_alloc_above() - allocate pages at or above given address
* @size: size of the memory area to allocate
* @align: minimum alignment of the allocated memory area. It should
* a power of two.
* @addr: on exit the address of the allocated memory
* @min: minimum address to used for the memory allocation
*
* Allocate at the lowest possible address that is not below @min as
* EFI_LOADER_DATA. The allocated pages are aligned according to @align but at
* least EFI_ALLOC_ALIGN. The first allocated page will not below the address
* given by @min.
*
* Return: status code
*/
efi_status_t efi_low_alloc_above(unsigned long size, unsigned long align,
unsigned long *addr, unsigned long min)
{
struct efi_boot_memmap *map __free(efi_pool) = NULL;
efi_status_t status;
unsigned long nr_pages;
int i;
status = efi_get_memory_map(&map, false);
if (status != EFI_SUCCESS)
return status;
/*
* 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->map_size / map->desc_size; i++) {
efi_memory_desc_t *desc;
unsigned long m = (unsigned long)map->map;
u64 start, end;
desc = efi_memdesc_ptr(m, map->desc_size, i);
if (desc->type != EFI_CONVENTIONAL_MEMORY)
continue;
if (desc->attribute & EFI_MEMORY_HOT_PLUGGABLE)
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->map_size / map->desc_size)
return EFI_NOT_FOUND;
return EFI_SUCCESS;
}
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