linux_dsm_epyc7002/arch/x86/platform
Matt Fleming 816e76129e efi: Allow drivers to reserve boot services forever
Today, it is not possible for drivers to reserve EFI boot services for
access after efi_free_boot_services() has been called on x86. For
ARM/arm64 it can be done simply by calling memblock_reserve().

Having this ability for all three architectures is desirable for a
couple of reasons,

  1) It saves drivers copying data out of those regions
  2) kexec reboot can now make use of things like ESRT

Instead of using the standard memblock_reserve() which is insufficient
to reserve the region on x86 (see efi_reserve_boot_services()), a new
API is introduced in this patch; efi_mem_reserve().

efi.memmap now always represents which EFI memory regions are
available. On x86 the EFI boot services regions that have not been
reserved via efi_mem_reserve() will be removed from efi.memmap during
efi_free_boot_services().

This has implications for kexec, since it is not possible for a newly
kexec'd kernel to access the same boot services regions that the
initial boot kernel had access to unless they are reserved by every
kexec kernel in the chain.

Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
2016-09-09 16:08:34 +01:00
..
atom x86/platform/atom/punit: Enable support for Merrifield 2016-06-14 12:44:51 +02:00
ce4100 x86/ce4100: Remove duplicated include from ce4100.c 2016-07-19 16:02:17 +02:00
efi efi: Allow drivers to reserve boot services forever 2016-09-09 16:08:34 +01:00
geode x86/platform: Make platform/geode/net5501.c explicitly non-modular 2016-02-16 09:11:09 +01:00
goldfish goldfish: platform device for x86 2013-01-21 12:09:19 -08:00
intel x86/platform/iosf_mbi: Add Intel Tangier PCI id 2015-07-16 17:48:48 +02:00
intel-mid RTC for 4.8 2016-08-05 09:48:22 -04:00
intel-quark x86/platform/intel/quark: Drop IMR lock bit support 2016-02-23 07:37:23 +01:00
iris x86: platform: iris: drop owner assignment from platform_drivers 2014-10-20 16:20:15 +02:00
olpc x86/platform: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:59 +02:00
scx200 X86: drivers: remove __dev* attributes. 2013-01-03 15:57:04 -08:00
sfi x86: Cleanup irq_domain ops 2015-04-24 15:36:55 +02:00
ts5500 x86/platform: Delete extraneous MODULE_* tags fromm ts5500 2016-07-16 22:41:00 +02:00
uv Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-08-12 14:31:10 -07:00
Makefile x86/platform/iosf_mbi: Move to dedicated folder 2015-07-16 17:48:47 +02:00