linux/drivers/firmware
Yasuaki Ishimatsu 46c66c4b7b memory-hotplug: remove /sys/firmware/memmap/X sysfs
When (hot)adding memory into system, /sys/firmware/memmap/X/{end, start,
type} sysfs files are created.  But there is no code to remove these
files.  This patch implements the function to remove them.

We cannot free firmware_map_entry which is allocated by bootmem because
there is no way to do so when the system is up.  But we can at least
remember the address of that memory and reuse the storage when the
memory is added next time.

This patch also introduces a new list map_entries_bootmem to link the
map entries allocated by bootmem when they are removed, and a lock to
protect it.  And these entries will be reused when the memory is
hot-added again.

The idea is suggestted by Andrew Morton.

NOTE: It is unsafe to return an entry pointer and release the
      map_entries_lock.  So we should not hold the map_entries_lock
      separately in firmware_map_find_entry() and
      firmware_map_remove_entry().  Hold the map_entries_lock across find
      and remove /sys/firmware/memmap/X operation.

       And also, users of these two functions need to be careful to
      hold the lock when using these two functions.

[tangchen@cn.fujitsu.com: Hold spinlock across find|remove /sys operation]
[tangchen@cn.fujitsu.com: fix the wrong comments of map_entries]
[tangchen@cn.fujitsu.com: reuse the storage of /sys/firmware/memmap/X/ allocated by bootmem]
[tangchen@cn.fujitsu.com: fix section mismatch problem]
[tangchen@cn.fujitsu.com: fix the doc format in drivers/firmware/memmap.c]
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Reviewed-by: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Julian Calaby <julian.calaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-23 17:50:12 -08:00
..
google firmware: google: fix gsmi.c build warning 2011-12-09 16:23:49 -08:00
dcdbas.c Drivers: misc: remove __dev* attributes. 2013-01-03 15:57:16 -08:00
dcdbas.h dcdbas: export functionality for use in other drivers 2009-01-08 08:31:12 -08:00
dell_rbu.c sysfs: add struct file* to bin_attr callbacks 2010-05-21 09:37:31 -07:00
dmi_scan.c efi: Make 'efi_enabled' a function to query EFI facilities 2013-01-30 11:51:59 -08:00
dmi-id.c dmi-id: fix a memory leak in dmi_id_init error path 2010-08-05 13:53:34 -07:00
dmi-sysfs.c firmware: Fix unaligned memory accesses in dmi-sysfs 2011-02-25 16:10:03 -08:00
edd.c [SCSI] edd: Treat "XPRS" host bus type the same as "PCI" 2011-10-31 13:26:19 +04:00
efivars.c A few fixes to reduce places where pstore might hang 2013-02-21 09:38:18 -08:00
iscsi_ibft_find.c efi: Make 'efi_enabled' a function to query EFI facilities 2013-01-30 11:51:59 -08:00
iscsi_ibft.c switch ->is_visible() to returning umode_t 2012-01-03 22:54:55 -05:00
Kconfig ASoC: Move SigmaDSP firmware loader to ASoC 2011-11-29 12:01:10 +00:00
Makefile ASoC: Move SigmaDSP firmware loader to ASoC 2011-11-29 12:01:10 +00:00
memmap.c memory-hotplug: remove /sys/firmware/memmap/X sysfs 2013-02-23 17:50:12 -08:00
pcdp.c pcdp: use early_ioremap/early_iounmap to access pcdp table 2012-07-30 17:25:11 -07:00
pcdp.h Update broken web addresses in the kernel. 2010-10-18 11:03:14 +02:00