// 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);
|
