Commit 0f96a99d authored by Taku Izumi's avatar Taku Izumi Committed by Matt Fleming
Browse files

efi: Add "efi_fake_mem" boot option



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: default avatarTaku 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: default avatarMatt Fleming <matt.fleming@intel.com>
parent 0bbea1ce
......@@ -1092,6 +1092,21 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
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]
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.
Using this parameter you can do debugging of EFI memmap
related feature. For example, you can do debugging of
Address Range Mirroring feature even if your box
doesn't support it.
eisa_irq_edge= [PARISC,HW]
See header of drivers/parisc/eisa.c.
......
......@@ -1104,8 +1104,10 @@ void __init setup_arch(char **cmdline_p)
memblock_set_current_limit(ISA_END_ADDRESS);
memblock_x86_fill();
if (efi_enabled(EFI_BOOT))
if (efi_enabled(EFI_BOOT)) {
efi_fake_memmap();
efi_find_mirror();
}
/*
* The EFI specification says that boot service code won't be called
......
......@@ -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
......
......@@ -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
/*
* 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);
......@@ -922,6 +922,12 @@ extern struct kobject *efi_kobj;
extern int efi_reboot_quirk_mode;
extern bool efi_poweroff_required(void);
#ifdef CONFIG_EFI_FAKE_MEMMAP
extern void __init efi_fake_memmap(void);
#else
static inline void efi_fake_memmap(void) { }
#endif
/* Iterate through an efi_memory_map */
#define for_each_efi_memory_desc(m, md) \
for ((md) = (m)->map; \
......
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