u-boot/lib/efi_loader/efi_memory.c

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/*
* EFI application memory management
*
* Copyright (c) 2016 Alexander Graf
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <efi_loader.h>
#include <malloc.h>
#include <asm/global_data.h>
#include <linux/libfdt_env.h>
#include <linux/list_sort.h>
#include <inttypes.h>
#include <watchdog.h>
DECLARE_GLOBAL_DATA_PTR;
struct efi_mem_list {
struct list_head link;
struct efi_mem_desc desc;
};
#define EFI_CARVE_NO_OVERLAP -1
#define EFI_CARVE_LOOP_AGAIN -2
#define EFI_CARVE_OVERLAPS_NONRAM -3
/* This list contains all memory map items */
LIST_HEAD(efi_mem);
#ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
void *efi_bounce_buffer;
#endif
/*
* U-Boot services each EFI AllocatePool request as a separate
* (multiple) page allocation. We have to track the number of pages
* to be able to free the correct amount later.
* EFI requires 8 byte alignment for pool allocations, so we can
* prepend each allocation with an 64 bit header tracking the
* allocation size, and hand out the remainder to the caller.
*/
struct efi_pool_allocation {
u64 num_pages;
char data[] __aligned(ARCH_DMA_MINALIGN);
};
/*
* Sorts the memory list from highest address to lowest address
*
* When allocating memory we should always start from the highest
* address chunk, so sort the memory list such that the first list
* iterator gets the highest address and goes lower from there.
*/
static int efi_mem_cmp(void *priv, struct list_head *a, struct list_head *b)
{
struct efi_mem_list *mema = list_entry(a, struct efi_mem_list, link);
struct efi_mem_list *memb = list_entry(b, struct efi_mem_list, link);
if (mema->desc.physical_start == memb->desc.physical_start)
return 0;
else if (mema->desc.physical_start < memb->desc.physical_start)
return 1;
else
return -1;
}
static void efi_mem_sort(void)
{
list_sort(NULL, &efi_mem, efi_mem_cmp);
}
/*
* Unmaps all memory occupied by the carve_desc region from the
* list entry pointed to by map.
*
* Returns EFI_CARVE_NO_OVERLAP if the regions don't overlap.
* Returns EFI_CARVE_OVERLAPS_NONRAM if the carve and map overlap,
* and the map contains anything but free ram.
* (only when overlap_only_ram is true)
* Returns EFI_CARVE_LOOP_AGAIN if the mapping list should be traversed
* again, as it has been altered
* Returns the number of overlapping pages. The pages are removed from
* the mapping list.
*
* In case of EFI_CARVE_OVERLAPS_NONRAM it is the callers responsibility
* to readd the already carved out pages to the mapping.
*/
static int efi_mem_carve_out(struct efi_mem_list *map,
struct efi_mem_desc *carve_desc,
bool overlap_only_ram)
{
struct efi_mem_list *newmap;
struct efi_mem_desc *map_desc = &map->desc;
uint64_t map_start = map_desc->physical_start;
uint64_t map_end = map_start + (map_desc->num_pages << EFI_PAGE_SHIFT);
uint64_t carve_start = carve_desc->physical_start;
uint64_t carve_end = carve_start +
(carve_desc->num_pages << EFI_PAGE_SHIFT);
/* check whether we're overlapping */
if ((carve_end <= map_start) || (carve_start >= map_end))
return EFI_CARVE_NO_OVERLAP;
/* We're overlapping with non-RAM, warn the caller if desired */
if (overlap_only_ram && (map_desc->type != EFI_CONVENTIONAL_MEMORY))
return EFI_CARVE_OVERLAPS_NONRAM;
/* Sanitize carve_start and carve_end to lie within our bounds */
carve_start = max(carve_start, map_start);
carve_end = min(carve_end, map_end);
/* Carving at the beginning of our map? Just move it! */
if (carve_start == map_start) {
if (map_end == carve_end) {
/* Full overlap, just remove map */
list_del(&map->link);
free(map);
} else {
map->desc.physical_start = carve_end;
map->desc.num_pages = (map_end - carve_end)
>> EFI_PAGE_SHIFT;
}
return (carve_end - carve_start) >> EFI_PAGE_SHIFT;
}
/*
* Overlapping maps, just split the list map at carve_start,
* it will get moved or removed in the next iteration.
*
* [ map_desc |__carve_start__| newmap ]
*/
/* Create a new map from [ carve_start ... map_end ] */
newmap = calloc(1, sizeof(*newmap));
newmap->desc = map->desc;
newmap->desc.physical_start = carve_start;
newmap->desc.num_pages = (map_end - carve_start) >> EFI_PAGE_SHIFT;
/* Insert before current entry (descending address order) */
list_add_tail(&newmap->link, &map->link);
/* Shrink the map to [ map_start ... carve_start ] */
map_desc->num_pages = (carve_start - map_start) >> EFI_PAGE_SHIFT;
return EFI_CARVE_LOOP_AGAIN;
}
uint64_t efi_add_memory_map(uint64_t start, uint64_t pages, int memory_type,
bool overlap_only_ram)
{
struct list_head *lhandle;
struct efi_mem_list *newlist;
bool carve_again;
uint64_t carved_pages = 0;
debug("%s: 0x%" PRIx64 " 0x%" PRIx64 " %d %s\n", __func__,
start, pages, memory_type, overlap_only_ram ? "yes" : "no");
if (!pages)
return start;
newlist = calloc(1, sizeof(*newlist));
newlist->desc.type = memory_type;
newlist->desc.physical_start = start;
newlist->desc.virtual_start = start;
newlist->desc.num_pages = pages;
switch (memory_type) {
case EFI_RUNTIME_SERVICES_CODE:
case EFI_RUNTIME_SERVICES_DATA:
newlist->desc.attribute = (1 << EFI_MEMORY_WB_SHIFT) |
(1ULL << EFI_MEMORY_RUNTIME_SHIFT);
break;
case EFI_MMAP_IO:
newlist->desc.attribute = 1ULL << EFI_MEMORY_RUNTIME_SHIFT;
break;
default:
newlist->desc.attribute = 1 << EFI_MEMORY_WB_SHIFT;
break;
}
/* Add our new map */
do {
carve_again = false;
list_for_each(lhandle, &efi_mem) {
struct efi_mem_list *lmem;
int r;
lmem = list_entry(lhandle, struct efi_mem_list, link);
r = efi_mem_carve_out(lmem, &newlist->desc,
overlap_only_ram);
switch (r) {
case EFI_CARVE_OVERLAPS_NONRAM:
/*
* The user requested to only have RAM overlaps,
* but we hit a non-RAM region. Error out.
*/
return 0;
case EFI_CARVE_NO_OVERLAP:
/* Just ignore this list entry */
break;
case EFI_CARVE_LOOP_AGAIN:
/*
* We split an entry, but need to loop through
* the list again to actually carve it.
*/
carve_again = true;
break;
default:
/* We carved a number of pages */
carved_pages += r;
carve_again = true;
break;
}
if (carve_again) {
/* The list changed, we need to start over */
break;
}
}
} while (carve_again);
if (overlap_only_ram && (carved_pages != pages)) {
/*
* The payload wanted to have RAM overlaps, but we overlapped
* with an unallocated region. Error out.
*/
return 0;
}
/* Add our new map */
list_add_tail(&newlist->link, &efi_mem);
/* And make sure memory is listed in descending order */
efi_mem_sort();
return start;
}
static uint64_t efi_find_free_memory(uint64_t len, uint64_t max_addr)
{
struct list_head *lhandle;
list_for_each(lhandle, &efi_mem) {
struct efi_mem_list *lmem = list_entry(lhandle,
struct efi_mem_list, link);
struct efi_mem_desc *desc = &lmem->desc;
uint64_t desc_len = desc->num_pages << EFI_PAGE_SHIFT;
uint64_t desc_end = desc->physical_start + desc_len;
uint64_t curmax = min(max_addr, desc_end);
uint64_t ret = curmax - len;
/* We only take memory from free RAM */
if (desc->type != EFI_CONVENTIONAL_MEMORY)
continue;
/* Out of bounds for max_addr */
if ((ret + len) > max_addr)
continue;
/* Out of bounds for upper map limit */
if ((ret + len) > desc_end)
continue;
/* Out of bounds for lower map limit */
if (ret < desc->physical_start)
continue;
/* Return the highest address in this map within bounds */
return ret;
}
return 0;
}
/*
* Allocate memory pages.
*
* @type type of allocation to be performed
* @memory_type usage type of the allocated memory
* @pages number of pages to be allocated
* @memory allocated memory
* @return status code
*/
efi_status_t efi_allocate_pages(int type, int memory_type,
efi_uintn_t pages, uint64_t *memory)
{
u64 len = pages << EFI_PAGE_SHIFT;
efi_status_t r = EFI_SUCCESS;
uint64_t addr;
switch (type) {
case 0:
/* Any page */
addr = efi_find_free_memory(len, gd->start_addr_sp);
if (!addr) {
r = EFI_NOT_FOUND;
break;
}
break;
case 1:
/* Max address */
addr = efi_find_free_memory(len, *memory);
if (!addr) {
r = EFI_NOT_FOUND;
break;
}
break;
case 2:
/* Exact address, reserve it. The addr is already in *memory. */
addr = *memory;
break;
default:
/* UEFI doesn't specify other allocation types */
r = EFI_INVALID_PARAMETER;
break;
}
if (r == EFI_SUCCESS) {
uint64_t ret;
/* Reserve that map in our memory maps */
ret = efi_add_memory_map(addr, pages, memory_type, true);
if (ret == addr) {
*memory = addr;
} else {
/* Map would overlap, bail out */
r = EFI_OUT_OF_RESOURCES;
}
}
return r;
}
void *efi_alloc(uint64_t len, int memory_type)
{
uint64_t ret = 0;
uint64_t pages = (len + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
efi_status_t r;
r = efi_allocate_pages(0, memory_type, pages, &ret);
if (r == EFI_SUCCESS)
return (void*)(uintptr_t)ret;
return NULL;
}
/*
* Free memory pages.
*
* @memory start of the memory area to be freed
* @pages number of pages to be freed
* @return status code
*/
efi_status_t efi_free_pages(uint64_t memory, efi_uintn_t pages)
{
uint64_t r = 0;
r = efi_add_memory_map(memory, pages, EFI_CONVENTIONAL_MEMORY, false);
/* Merging of adjacent free regions is missing */
if (r == memory)
return EFI_SUCCESS;
return EFI_NOT_FOUND;
}
/*
* Allocate memory from pool.
*
* @pool_type type of the pool from which memory is to be allocated
* @size number of bytes to be allocated
* @buffer allocated memory
* @return status code
*/
efi_status_t efi_allocate_pool(int pool_type, efi_uintn_t size, void **buffer)
{
efi_status_t r;
efi_physical_addr_t t;
u64 num_pages = (size + sizeof(struct efi_pool_allocation) +
EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
if (size == 0) {
*buffer = NULL;
return EFI_SUCCESS;
}
r = efi_allocate_pages(0, pool_type, num_pages, &t);
if (r == EFI_SUCCESS) {
struct efi_pool_allocation *alloc = (void *)(uintptr_t)t;
alloc->num_pages = num_pages;
*buffer = alloc->data;
}
return r;
}
/*
* Free memory from pool.
*
* @buffer start of memory to be freed
* @return status code
*/
efi_status_t efi_free_pool(void *buffer)
{
efi_status_t r;
struct efi_pool_allocation *alloc;
if (buffer == NULL)
return EFI_INVALID_PARAMETER;
alloc = container_of(buffer, struct efi_pool_allocation, data);
/* Sanity check, was the supplied address returned by allocate_pool */
assert(((uintptr_t)alloc & EFI_PAGE_MASK) == 0);
r = efi_free_pages((uintptr_t)alloc, alloc->num_pages);
return r;
}
/*
* Get map describing memory usage.
*
* @memory_map_size on entry the size, in bytes, of the memory map buffer,
* on exit the size of the copied memory map
* @memory_map buffer to which the memory map is written
* @map_key key for the memory map
* @descriptor_size size of an individual memory descriptor
* @descriptor_version version number of the memory descriptor structure
* @return status code
*/
efi_status_t efi_get_memory_map(efi_uintn_t *memory_map_size,
struct efi_mem_desc *memory_map,
efi_uintn_t *map_key,
efi_uintn_t *descriptor_size,
uint32_t *descriptor_version)
{
efi_uintn_t map_size = 0;
int map_entries = 0;
struct list_head *lhandle;
efi_uintn_t provided_map_size = *memory_map_size;
list_for_each(lhandle, &efi_mem)
map_entries++;
map_size = map_entries * sizeof(struct efi_mem_desc);
*memory_map_size = map_size;
if (provided_map_size < map_size)
return EFI_BUFFER_TOO_SMALL;
if (descriptor_size)
*descriptor_size = sizeof(struct efi_mem_desc);
if (descriptor_version)
*descriptor_version = EFI_MEMORY_DESCRIPTOR_VERSION;
/* Copy list into array */
if (memory_map) {
/* Return the list in ascending order */
memory_map = &memory_map[map_entries - 1];
list_for_each(lhandle, &efi_mem) {
struct efi_mem_list *lmem;
lmem = list_entry(lhandle, struct efi_mem_list, link);
*memory_map = lmem->desc;
memory_map--;
}
}
*map_key = 0;
return EFI_SUCCESS;
}
__weak void efi_add_known_memory(void)
{
int i;
/* Add RAM */
for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
u64 ram_start = gd->bd->bi_dram[i].start;
u64 ram_size = gd->bd->bi_dram[i].size;
u64 start = (ram_start + EFI_PAGE_MASK) & ~EFI_PAGE_MASK;
u64 pages = (ram_size + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
efi_add_memory_map(start, pages, EFI_CONVENTIONAL_MEMORY,
false);
}
}
int efi_memory_init(void)
{
unsigned long runtime_start, runtime_end, runtime_pages;
unsigned long uboot_start, uboot_pages;
unsigned long uboot_stack_size = 16 * 1024 * 1024;
efi_add_known_memory();
/* Add U-Boot */
uboot_start = (gd->start_addr_sp - uboot_stack_size) & ~EFI_PAGE_MASK;
uboot_pages = (gd->ram_top - uboot_start) >> EFI_PAGE_SHIFT;
efi_add_memory_map(uboot_start, uboot_pages, EFI_LOADER_DATA, false);
/* Add Runtime Services */
runtime_start = (ulong)&__efi_runtime_start & ~EFI_PAGE_MASK;
runtime_end = (ulong)&__efi_runtime_stop;
runtime_end = (runtime_end + EFI_PAGE_MASK) & ~EFI_PAGE_MASK;
runtime_pages = (runtime_end - runtime_start) >> EFI_PAGE_SHIFT;
efi_add_memory_map(runtime_start, runtime_pages,
EFI_RUNTIME_SERVICES_CODE, false);
#ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
/* Request a 32bit 64MB bounce buffer region */
uint64_t efi_bounce_buffer_addr = 0xffffffff;
if (efi_allocate_pages(1, EFI_LOADER_DATA,
(64 * 1024 * 1024) >> EFI_PAGE_SHIFT,
&efi_bounce_buffer_addr) != EFI_SUCCESS)
return -1;
efi_bounce_buffer = (void*)(uintptr_t)efi_bounce_buffer_addr;
#endif
return 0;
}