you are really sure that your UEFI does sane gc and
fulfills the spec otherwise your board may brick.
- efi_fake_mem= nn[KMG]@ss[KMG]:aa[,nn[KMG]@ss[KMG]:aa,..] [EFI,X86,EARLY]
- Add arbitrary attribute to specific memory range by
- updating original EFI memory map.
- Region of memory which aa attribute is added to is
- from ss to ss+nn.
-
- If efi_fake_mem=2G@4G:0x10000,2G@0x10a0000000:0x10000
- is specified, EFI_MEMORY_MORE_RELIABLE(0x10000)
- attribute is added to range 0x100000000-0x180000000 and
- 0x10a0000000-0x1120000000.
-
- If efi_fake_mem=8G@9G:0x40000 is specified, the
- EFI_MEMORY_SP(0x40000) attribute is added to
- range 0x240000000-0x43fffffff.
-
- Using this parameter you can do debugging of EFI memmap
- related features. For example, you can do debugging of
- Address Range Mirroring feature even if your box
- doesn't support it, or mark specific memory as
- "soft reserved".
-
efivar_ssdt= [EFI; X86] Name of an EFI variable that contains an SSDT
that is to be dynamically loaded by Linux. If there are
multiple variables with the same name but with different
#include "../../../../lib/ctype.c"
#include "../../../../lib/cmdline.c"
-enum parse_mode {
- PARSE_MEMMAP,
- PARSE_EFI,
-};
-
static int
-parse_memmap(char *p, u64 *start, u64 *size, enum parse_mode mode)
+parse_memmap(char *p, u64 *start, u64 *size)
{
char *oldp;
*start = memparse(p + 1, &p);
return 0;
case '@':
- if (mode == PARSE_MEMMAP) {
- /*
- * memmap=nn@ss specifies usable region, should
- * be skipped
- */
- *size = 0;
- } else {
- u64 flags;
-
- /*
- * efi_fake_mem=nn@ss:attr the attr specifies
- * flags that might imply a soft-reservation.
- */
- *start = memparse(p + 1, &p);
- if (p && *p == ':') {
- p++;
- if (kstrtoull(p, 0, &flags) < 0)
- *size = 0;
- else if (flags & EFI_MEMORY_SP)
- return 0;
- }
- *size = 0;
- }
+ /*
+ * memmap=nn@ss specifies usable region, should
+ * be skipped
+ */
+ *size = 0;
fallthrough;
default:
/*
return -EINVAL;
}
-static void mem_avoid_memmap(enum parse_mode mode, char *str)
+static void mem_avoid_memmap(char *str)
{
static int i;
if (k)
*k++ = 0;
- rc = parse_memmap(str, &start, &size, mode);
+ rc = parse_memmap(str, &start, &size);
if (rc < 0)
break;
str = k;
break;
if (!strcmp(param, "memmap")) {
- mem_avoid_memmap(PARSE_MEMMAP, val);
+ mem_avoid_memmap(val);
} else if (IS_ENABLED(CONFIG_X86_64) && strstr(param, "hugepages")) {
parse_gb_huge_pages(param, val);
} else if (!strcmp(param, "mem")) {
if (mem_size < mem_limit)
mem_limit = mem_size;
- } else if (!strcmp(param, "efi_fake_mem")) {
- mem_avoid_memmap(PARSE_EFI, val);
}
}
+++ /dev/null
-// 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 <asm/e820/api.h>
-#include <asm/efi.h>
-
-#define EFI_MAX_FAKEMEM CONFIG_EFI_MAX_FAKE_MEM
-
-static struct efi_mem_range efi_fake_mems[EFI_MAX_FAKEMEM];
-static 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);
-
-void __init efi_fake_memmap_early(void)
-{
- int i;
-
- /*
- * The late efi_fake_mem() call can handle all requests if
- * EFI_MEMORY_SP support is disabled.
- */
- if (!efi_soft_reserve_enabled())
- return;
-
- if (!efi_enabled(EFI_MEMMAP) || !nr_fake_mem)
- return;
-
- /*
- * Given that efi_fake_memmap() needs to perform memblock
- * allocations it needs to run after e820__memblock_setup().
- * However, if efi_fake_mem specifies EFI_MEMORY_SP for a given
- * address range that potentially needs to mark the memory as
- * reserved prior to e820__memblock_setup(). Update e820
- * directly if EFI_MEMORY_SP is specified for an
- * EFI_CONVENTIONAL_MEMORY descriptor.
- */
- for (i = 0; i < nr_fake_mem; i++) {
- struct efi_mem_range *mem = &efi_fake_mems[i];
- efi_memory_desc_t *md;
- u64 m_start, m_end;
-
- if ((mem->attribute & EFI_MEMORY_SP) == 0)
- continue;
-
- m_start = mem->range.start;
- m_end = mem->range.end;
- for_each_efi_memory_desc(md) {
- u64 start, end, size;
-
- if (md->type != EFI_CONVENTIONAL_MEMORY)
- continue;
-
- start = md->phys_addr;
- end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1;
-
- if (m_start <= end && m_end >= start)
- /* fake range overlaps descriptor */;
- else
- continue;
-
- /*
- * Trim the boundary of the e820 update to the
- * descriptor in case the fake range overlaps
- * !EFI_CONVENTIONAL_MEMORY
- */
- start = max(start, m_start);
- end = min(end, m_end);
- size = end - start + 1;
-
- if (end <= start)
- continue;
-
- /*
- * Ensure each efi_fake_mem instance results in
- * a unique e820 resource
- */
- e820__range_remove(start, size, E820_TYPE_RAM, 1);
- e820__range_add(start, size, E820_TYPE_SOFT_RESERVED);
- e820__update_table(e820_table);
- }
- }
-}
projects / linux-block.git / commitdiff