linux/arch/x86
Yinghai Lu 0212f91596 x86: Add Crash kernel low reservation
During kdump kernel's booting stage, it need to find low ram for
swiotlb buffer when system does not support intel iommu/dmar remapping.

kexed-tools is appending memmap=exactmap and range from /proc/iomem
with "Crash kernel", and that range is above 4G for 64bit after boot
protocol 2.12.

We need to add another range in /proc/iomem like "Crash kernel low",
so kexec-tools could find that info and append to kdump kernel
command line.

Try to reserve some under 4G if the normal "Crash kernel" is above 4G.

User could specify the size with crashkernel_low=XX[KMG].

-v2: fix warning that is found by Fengguang's test robot.
-v3: move out get_mem_size change to another patch, to solve compiling
     warning that is found by Borislav Petkov <bp@alien8.de>
-v4: user must specify crashkernel_low if system does not support
     intel or amd iommu.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1359058816-7615-31-git-send-email-yinghai@kernel.org
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Rob Landley <rob@landley.net>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-01-29 19:32:58 -08:00
..
boot x86, boot: Update comments about entries for 64bit image 2013-01-29 19:32:57 -08:00
configs x86/Kconfig: Turn off DEBUG_NX_TEST module in defconfigs 2012-09-05 10:43:12 +02:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2012-12-15 12:35:19 -08:00
ia32 new helpers: __save_altstack/__compat_save_altstack, switch x86 and um to those 2012-12-19 18:07:41 -05:00
include x86, kexec, 64bit: Only set ident mapping for ram. 2013-01-29 15:26:35 -08:00
kernel x86: Add Crash kernel low reservation 2013-01-29 19:32:58 -08:00
kvm KVM: x86: use dynamic percpu allocations for shared msrs area 2013-01-08 12:51:56 -02:00
lguest x86, MCA: Finish mca_config conversion 2012-10-26 14:37:58 +02:00
lib X86: drivers: remove __dev* attributes. 2013-01-03 15:57:04 -08:00
math-emu
mm x86, kexec, 64bit: Only set ident mapping for ram. 2013-01-29 15:26:35 -08:00
net x86: bpf_jit_comp: add vlan tag support 2012-10-31 14:00:15 -04:00
oprofile oprofile, x86: Fix wrapping bug in op_x86_get_ctrl() 2012-10-15 14:38:24 +02:00
pci X86: drivers: remove __dev* attributes. 2013-01-03 15:57:04 -08:00
platform Merge remote-tracking branch 'origin/x86/boot' into x86/mm2 2013-01-29 15:10:15 -08:00
power x86, topology: Debug CPU0 hotplug 2012-11-14 15:28:11 -08:00
realmode x86, realmode: Separate real_mode reserve and setup 2013-01-29 15:13:24 -08:00
syscalls Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2012-12-20 18:05:28 -08:00
tools x86/boot: Fix minor fd leakage in tools/relocs.c 2013-01-27 10:24:28 -08:00
um Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2012-12-20 18:05:28 -08:00
vdso Merge tag 'kvm-3.8-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2012-12-13 15:31:08 -08:00
video x86: Use vga_default_device() when determining whether an fb is primary 2012-04-24 09:50:17 +01:00
xen Merge remote-tracking branch 'origin/x86/boot' into x86/mm2 2013-01-29 15:10:15 -08:00
.gitignore
Kbuild x86, realmode: realmode.bin infrastructure 2012-05-08 11:41:48 -07:00
Kconfig Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2012-12-20 18:05:28 -08:00
Kconfig.cpu x86, 386 removal: Document Nx586 as a 386 and thus unsupported 2012-11-29 13:28:39 -08:00
Kconfig.debug x86/tlb: add tlb_flushall_shift knob into debugfs 2012-06-27 19:29:10 -07:00
Makefile md update for 3.8 2012-12-18 09:32:44 -08:00
Makefile_32.cpu x86, 386 removal: Remove CONFIG_M386 from Kconfig 2012-11-29 13:23:01 -08:00
Makefile.um um: fix linker script generation 2012-04-09 13:59:00 -04:00