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author | Bernhard Walle <bwalle@suse.de> | 2008-06-27 13:12:54 +0200 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2008-07-08 17:55:41 +0200 |
commit | 69ac9cd629ca96e59f34eb4ccd12d00b2c8276a7 (patch) | |
tree | e9bb108c5ec36c666d64a52ca35ccf0197c84306 /include/linux/firmware-map.h | |
parent | 6247943d8ab699b57653afd453a4940cca70ef8a (diff) | |
download | linux-stable-69ac9cd629ca96e59f34eb4ccd12d00b2c8276a7.tar.gz linux-stable-69ac9cd629ca96e59f34eb4ccd12d00b2c8276a7.tar.bz2 linux-stable-69ac9cd629ca96e59f34eb4ccd12d00b2c8276a7.zip |
sysfs: add /sys/firmware/memmap
This patch adds /sys/firmware/memmap interface that represents the BIOS
(or Firmware) provided memory map. The tree looks like:
/sys/firmware/memmap/0/start (hex number)
end (hex number)
type (string)
... /1/start
end
type
With the following shell snippet one can print the memory map in the same form
the kernel prints itself when booting on x86 (the E820 map).
--------- 8< --------------------------
#!/bin/sh
cd /sys/firmware/memmap
for dir in * ; do
start=$(cat $dir/start)
end=$(cat $dir/end)
type=$(cat $dir/type)
printf "%016x-%016x (%s)\n" $start $[ $end +1] "$type"
done
--------- >8 --------------------------
That patch only provides the needed interface:
1. The sysfs interface.
2. The structure and enumeration definition.
3. The function firmware_map_add() and firmware_map_add_early()
that should be called from architecture code (E820/EFI, for
example) to add the contents to the interface.
If the kernel is compiled without CONFIG_FIRMWARE_MEMMAP, the interface does
nothing without cluttering the architecture-specific code with #ifdef's.
The purpose of the new interface is kexec: While /proc/iomem represents
the *used* memory map (e.g. modified via kernel parameters like 'memmap'
and 'mem'), the /sys/firmware/memmap tree represents the unmodified memory
map provided via the firmware. So kexec can:
- use the original memory map for rebooting,
- use the /proc/iomem for setting up the ELF core headers for kdump
case that should only represent the memory of the system.
The patch has been tested on i386 and x86_64.
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Acked-by: Greg KH <gregkh@suse.de>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: kexec@lists.infradead.org
Cc: yhlu.kernel@gmail.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/firmware-map.h')
-rw-r--r-- | include/linux/firmware-map.h | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/include/linux/firmware-map.h b/include/linux/firmware-map.h new file mode 100644 index 000000000000..acbdbcc16051 --- /dev/null +++ b/include/linux/firmware-map.h @@ -0,0 +1,74 @@ +/* + * include/linux/firmware-map.h: + * Copyright (C) 2008 SUSE LINUX Products GmbH + * by Bernhard Walle <bwalle@suse.de> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License v2.0 as published by + * the Free Software Foundation + * + * This program is distributed in the hope that 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. + * + */ +#ifndef _LINUX_FIRMWARE_MAP_H +#define _LINUX_FIRMWARE_MAP_H + +#include <linux/list.h> +#include <linux/kobject.h> + +/* + * provide a dummy interface if CONFIG_FIRMWARE_MEMMAP is disabled + */ +#ifdef CONFIG_FIRMWARE_MEMMAP + +/** + * Adds a firmware mapping entry. This function uses kmalloc() for memory + * allocation. Use firmware_map_add_early() if you want to use the bootmem + * allocator. + * + * That function must be called before late_initcall. + * + * @start: Start of the memory range. + * @end: End of the memory range (inclusive). + * @type: Type of the memory range. + * + * Returns 0 on success, or -ENOMEM if no memory could be allocated. + */ +int firmware_map_add(resource_size_t start, resource_size_t end, + const char *type); + +/** + * Adds a firmware mapping entry. This function uses the bootmem allocator + * for memory allocation. Use firmware_map_add() if you want to use kmalloc(). + * + * That function must be called before late_initcall. + * + * @start: Start of the memory range. + * @end: End of the memory range (inclusive). + * @type: Type of the memory range. + * + * Returns 0 on success, or -ENOMEM if no memory could be allocated. + */ +int firmware_map_add_early(resource_size_t start, resource_size_t end, + const char *type); + +#else /* CONFIG_FIRMWARE_MEMMAP */ + +static inline int firmware_map_add(resource_size_t start, resource_size_t end, + const char *type) +{ + return 0; +} + +static inline int firmware_map_add_early(resource_size_t start, + resource_size_t end, const char *type) +{ + return 0; +} + +#endif /* CONFIG_FIRMWARE_MEMMAP */ + +#endif /* _LINUX_FIRMWARE_MAP_H */ |