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efi: Add "efi_fake_mem" boot option

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This patch introduces new boot option named "efi_fake_mem".
By specifying this parameter, you can add arbitrary attribute
to specific memory range.
This is useful for debugging of Address Range Mirroring feature.

For example, if "efi_fake_mem=2G@4G:0x10000,2G@0x10a0000000:0x10000"
is specified, the original (firmware provided) EFI memmap will be
updated so that the specified memory regions have
EFI_MEMORY_MORE_RELIABLE attribute (0x10000):

 <original>
   efi: mem36: [Conventional Memory|  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000100000000-0x00000020a0000000) (129536MB)

 <updated>
   efi: mem36: [Conventional Memory|  |MR|  |  |  |   |WB|WT|WC|UC] range=[0x0000000100000000-0x0000000180000000) (2048MB)
   efi: mem37: [Conventional Memory|  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000000180000000-0x00000010a0000000) (61952MB)
   efi: mem38: [Conventional Memory|  |MR|  |  |  |   |WB|WT|WC|UC] range=[0x00000010a0000000-0x0000001120000000) (2048MB)
   efi: mem39: [Conventional Memory|  |  |  |  |  |   |WB|WT|WC|UC] range=[0x0000001120000000-0x00000020a0000000) (63488MB)

And you will find that the following message is output:

   efi: Memory: 4096M/131455M mirrored memory

Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
This commit is contained in:
Taku Izumi
2015-09-30 23:01:56 +09:00
committed by Matt Fleming
parent 0bbea1ce98
commit 0f96a99dab
6 changed files with 285 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files
drivers/firmware/efi/Kconfig
+22
View File
@@ -52,6 +52,28 @@ config EFI_RUNTIME_MAP
See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map.
config EFI_FAKE_MEMMAP
bool "Enable EFI fake memory map"
depends on EFI && X86
default n
help
Saying Y here will enable "efi_fake_mem" boot option.
By specifying this parameter, you can add arbitrary attribute
to specific memory range by updating original (firmware provided)
EFI memmap.
This is useful for debugging of EFI memmap related feature.
e.g. Address Range Mirroring feature.
config EFI_MAX_FAKE_MEM
int "maximum allowable number of ranges in efi_fake_mem boot option"
depends on EFI_FAKE_MEMMAP
range 1 128
default 8
help
Maximum allowable number of ranges in efi_fake_mem boot option.
Ranges can be set up to this value using comma-separated list.
The default value is 8.
config EFI_PARAMS_FROM_FDT
bool
help
drivers/firmware/efi/Makefile
+1
View File
@@ -9,3 +9,4 @@ obj-$(CONFIG_UEFI_CPER) += cper.o
obj-$(CONFIG_EFI_RUNTIME_MAP) += runtime-map.o
obj-$(CONFIG_EFI_RUNTIME_WRAPPERS) += runtime-wrappers.o
obj-$(CONFIG_EFI_STUB) += libstub/
obj-$(CONFIG_EFI_FAKE_MEMMAP) += fake_mem.o
drivers/firmware/efi/fake_mem.c
+238
View File
@@ -0,0 +1,238 @@
/*
* 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.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, see <http://www.gnu.org/licenses/>.
*
* The full GNU General Public License is included in this distribution in
* the file called "COPYING".
*/
#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/efi.h>
#define EFI_MAX_FAKEMEM CONFIG_EFI_MAX_FAKE_MEM
struct fake_mem {
struct range range;
u64 attribute;
};
static struct fake_mem fake_mems[EFI_MAX_FAKEMEM];
static int nr_fake_mem;
static int __init cmp_fake_mem(const void *x1, const void *x2)
{
const struct fake_mem *m1 = x1;
const struct fake_mem *m2 = x2;
if (m1->range.start < m2->range.start)
return -1;
if (m1->range.start > m2->range.start)
return 1;
return 0;
}
void __init efi_fake_memmap(void)
{
u64 start, end, m_start, m_end, m_attr;
int new_nr_map = memmap.nr_map;
efi_memory_desc_t *md;
u64 new_memmap_phy;
void *new_memmap;
void *old, *new;
int i;
if (!nr_fake_mem || !efi_enabled(EFI_MEMMAP))
return;
/* count up the number of EFI memory descriptor */
for (old = memmap.map; old < memmap.map_end; old += memmap.desc_size) {
md = old;
start = md->phys_addr;
end = start + (md->num_pages << EFI_PAGE_SHIFT) - 1;
for (i = 0; i < nr_fake_mem; i++) {
/* modifying range */
m_start = fake_mems[i].range.start;
m_end = fake_mems[i].range.end;
if (m_start <= start) {
/* split into 2 parts */
if (start < m_end && m_end < end)
new_nr_map++;
}
if (start < m_start && m_start < end) {
/* split into 3 parts */
if (m_end < end)
new_nr_map += 2;
/* split into 2 parts */
if (end <= m_end)
new_nr_map++;
}
}
}
/* allocate memory for new EFI memmap */
new_memmap_phy = memblock_alloc(memmap.desc_size * new_nr_map,
PAGE_SIZE);
if (!new_memmap_phy)
return;
/* create new EFI memmap */
new_memmap = early_memremap(new_memmap_phy,
memmap.desc_size * new_nr_map);
if (!new_memmap) {
memblock_free(new_memmap_phy, memmap.desc_size * new_nr_map);
return;
}
for (old = memmap.map, new = new_memmap;
old < memmap.map_end;
old += memmap.desc_size, new += memmap.desc_size) {
/* copy original EFI memory descriptor */
memcpy(new, old, memmap.desc_size);
md = new;
start = md->phys_addr;
end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1;
for (i = 0; i < nr_fake_mem; i++) {
/* modifying range */
m_start = fake_mems[i].range.start;
m_end = fake_mems[i].range.end;
m_attr = fake_mems[i].attribute;
if (m_start <= start && end <= m_end)
md->attribute |= m_attr;
if (m_start <= start &&
(start < m_end && m_end < end)) {
/* first part */
md->attribute |= m_attr;
md->num_pages = (m_end - md->phys_addr + 1) >>
EFI_PAGE_SHIFT;
/* latter part */
new += memmap.desc_size;
memcpy(new, old, memmap.desc_size);
md = new;
md->phys_addr = m_end + 1;
md->num_pages = (end - md->phys_addr + 1) >>
EFI_PAGE_SHIFT;
}
if ((start < m_start && m_start < end) && m_end < end) {
/* first part */
md->num_pages = (m_start - md->phys_addr) >>
EFI_PAGE_SHIFT;
/* middle part */
new += memmap.desc_size;
memcpy(new, old, memmap.desc_size);
md = new;
md->attribute |= m_attr;
md->phys_addr = m_start;
md->num_pages = (m_end - m_start + 1) >>
EFI_PAGE_SHIFT;
/* last part */
new += memmap.desc_size;
memcpy(new, old, memmap.desc_size);
md = new;
md->phys_addr = m_end + 1;
md->num_pages = (end - m_end) >>
EFI_PAGE_SHIFT;
}
if ((start < m_start && m_start < end) &&
(end <= m_end)) {
/* first part */
md->num_pages = (m_start - md->phys_addr) >>
EFI_PAGE_SHIFT;
/* latter part */
new += memmap.desc_size;
memcpy(new, old, memmap.desc_size);
md = new;
md->phys_addr = m_start;
md->num_pages = (end - md->phys_addr + 1) >>
EFI_PAGE_SHIFT;
md->attribute |= m_attr;
}
}
}
/* swap into new EFI memmap */
efi_unmap_memmap();
memmap.map = new_memmap;
memmap.phys_map = (void *)new_memmap_phy;
memmap.nr_map = new_nr_map;
memmap.map_end = memmap.map + memmap.nr_map * memmap.desc_size;
set_bit(EFI_MEMMAP, &efi.flags);
/* 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;
fake_mems[nr_fake_mem].range.start = start;
fake_mems[nr_fake_mem].range.end = start + mem_size - 1;
fake_mems[nr_fake_mem].attribute = attribute;
nr_fake_mem++;
if (*p == ',')
p++;
}
sort(fake_mems, nr_fake_mem, sizeof(struct fake_mem),
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]",
fake_mems[i].attribute, fake_mems[i].range.start,
fake_mems[i].range.end);
return *p == '\0' ? 0 : -EINVAL;
}
early_param("efi_fake_mem", setup_fake_mem);