^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Copyright (C) 2016 Linaro Ltd; <ard.biesheuvel@linaro.org>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) #include <linux/efi.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) #include <linux/log2.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <asm/efi.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include "efistub.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) * Return the number of slots covered by this entry, i.e., the number of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) * addresses it covers that are suitably aligned and supply enough room
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) * for the allocation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) static unsigned long get_entry_num_slots(efi_memory_desc_t *md,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) unsigned long size,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) unsigned long align_shift)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) unsigned long align = 1UL << align_shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) u64 first_slot, last_slot, region_end;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) if (md->type != EFI_CONVENTIONAL_MEMORY)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) if (efi_soft_reserve_enabled() &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) (md->attribute & EFI_MEMORY_SP))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) region_end = min(md->phys_addr + md->num_pages * EFI_PAGE_SIZE - 1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) (u64)ULONG_MAX);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) if (region_end < size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) first_slot = round_up(md->phys_addr, align);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) last_slot = round_down(region_end - size + 1, align);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) if (first_slot > last_slot)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) return ((unsigned long)(last_slot - first_slot) >> align_shift) + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) * The UEFI memory descriptors have a virtual address field that is only used
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) * when installing the virtual mapping using SetVirtualAddressMap(). Since it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) * is unused here, we can reuse it to keep track of each descriptor's slot
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) * count.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) #define MD_NUM_SLOTS(md) ((md)->virt_addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) efi_status_t efi_random_alloc(unsigned long size,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) unsigned long align,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) unsigned long *addr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) unsigned long random_seed)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) unsigned long map_size, desc_size, total_slots = 0, target_slot;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) unsigned long buff_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) efi_status_t status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) efi_memory_desc_t *memory_map;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) int map_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) struct efi_boot_memmap map;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) map.map = &memory_map;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) map.map_size = &map_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) map.desc_size = &desc_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) map.desc_ver = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) map.key_ptr = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) map.buff_size = &buff_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) status = efi_get_memory_map(&map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) if (status != EFI_SUCCESS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) return status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) if (align < EFI_ALLOC_ALIGN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) align = EFI_ALLOC_ALIGN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) size = round_up(size, EFI_ALLOC_ALIGN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) /* count the suitable slots in each memory map entry */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) for (map_offset = 0; map_offset < map_size; map_offset += desc_size) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) efi_memory_desc_t *md = (void *)memory_map + map_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) unsigned long slots;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) slots = get_entry_num_slots(md, size, ilog2(align));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) MD_NUM_SLOTS(md) = slots;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) total_slots += slots;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) /* find a random number between 0 and total_slots */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) target_slot = (total_slots * (u64)(random_seed & U32_MAX)) >> 32;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) * target_slot is now a value in the range [0, total_slots), and so
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) * it corresponds with exactly one of the suitable slots we recorded
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) * when iterating over the memory map the first time around.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) * So iterate over the memory map again, subtracting the number of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) * slots of each entry at each iteration, until we have found the entry
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) * that covers our chosen slot. Use the residual value of target_slot
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) * to calculate the randomly chosen address, and allocate it directly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) * using EFI_ALLOCATE_ADDRESS.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) for (map_offset = 0; map_offset < map_size; map_offset += desc_size) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) efi_memory_desc_t *md = (void *)memory_map + map_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) efi_physical_addr_t target;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) unsigned long pages;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) if (target_slot >= MD_NUM_SLOTS(md)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) target_slot -= MD_NUM_SLOTS(md);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) target = round_up(md->phys_addr, align) + target_slot * align;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) pages = size / EFI_PAGE_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) status = efi_bs_call(allocate_pages, EFI_ALLOCATE_ADDRESS,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) EFI_LOADER_DATA, pages, &target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) if (status == EFI_SUCCESS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) *addr = target;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) efi_bs_call(free_pool, memory_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) return status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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