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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/firmware/efi/fake_mem.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/firmware/efi/fake_mem.c')
-rw-r--r-- | drivers/firmware/efi/fake_mem.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/drivers/firmware/efi/fake_mem.c b/drivers/firmware/efi/fake_mem.c new file mode 100644 index 000000000..6e0f34a38 --- /dev/null +++ b/drivers/firmware/efi/fake_mem.c @@ -0,0 +1,124 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * fake_mem.c + * + * Copyright (C) 2015 FUJITSU LIMITED + * Author: Taku Izumi <izumi.taku@jp.fujitsu.com> + * + * This code introduces new boot option named "efi_fake_mem" + * By specifying this parameter, you can add arbitrary attribute to + * specific memory range by updating original (firmware provided) EFI + * memmap. + */ + +#include <linux/kernel.h> +#include <linux/efi.h> +#include <linux/init.h> +#include <linux/memblock.h> +#include <linux/types.h> +#include <linux/sort.h> +#include "fake_mem.h" + +struct efi_mem_range efi_fake_mems[EFI_MAX_FAKEMEM]; +int nr_fake_mem; + +static int __init cmp_fake_mem(const void *x1, const void *x2) +{ + const struct efi_mem_range *m1 = x1; + const struct efi_mem_range *m2 = x2; + + if (m1->range.start < m2->range.start) + return -1; + if (m1->range.start > m2->range.start) + return 1; + return 0; +} + +static void __init efi_fake_range(struct efi_mem_range *efi_range) +{ + struct efi_memory_map_data data = { 0 }; + int new_nr_map = efi.memmap.nr_map; + efi_memory_desc_t *md; + void *new_memmap; + + /* count up the number of EFI memory descriptor */ + for_each_efi_memory_desc(md) + new_nr_map += efi_memmap_split_count(md, &efi_range->range); + + /* allocate memory for new EFI memmap */ + if (efi_memmap_alloc(new_nr_map, &data) != 0) + return; + + /* create new EFI memmap */ + new_memmap = early_memremap(data.phys_map, data.size); + if (!new_memmap) { + __efi_memmap_free(data.phys_map, data.size, data.flags); + return; + } + + efi_memmap_insert(&efi.memmap, new_memmap, efi_range); + + /* swap into new EFI memmap */ + early_memunmap(new_memmap, data.size); + + efi_memmap_install(&data); +} + +void __init efi_fake_memmap(void) +{ + int i; + + if (!efi_enabled(EFI_MEMMAP) || !nr_fake_mem) + return; + + for (i = 0; i < nr_fake_mem; i++) + efi_fake_range(&efi_fake_mems[i]); + + /* print new EFI memmap */ + efi_print_memmap(); +} + +static int __init setup_fake_mem(char *p) +{ + u64 start = 0, mem_size = 0, attribute = 0; + int i; + + if (!p) + return -EINVAL; + + while (*p != '\0') { + mem_size = memparse(p, &p); + if (*p == '@') + start = memparse(p+1, &p); + else + break; + + if (*p == ':') + attribute = simple_strtoull(p+1, &p, 0); + else + break; + + if (nr_fake_mem >= EFI_MAX_FAKEMEM) + break; + + efi_fake_mems[nr_fake_mem].range.start = start; + efi_fake_mems[nr_fake_mem].range.end = start + mem_size - 1; + efi_fake_mems[nr_fake_mem].attribute = attribute; + nr_fake_mem++; + + if (*p == ',') + p++; + } + + sort(efi_fake_mems, nr_fake_mem, sizeof(struct efi_mem_range), + cmp_fake_mem, NULL); + + for (i = 0; i < nr_fake_mem; i++) + pr_info("efi_fake_mem: add attr=0x%016llx to [mem 0x%016llx-0x%016llx]", + efi_fake_mems[i].attribute, efi_fake_mems[i].range.start, + efi_fake_mems[i].range.end); + + return *p == '\0' ? 0 : -EINVAL; +} + +early_param("efi_fake_mem", setup_fake_mem); |