linux/arch
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
..
alpha RTC for 4.8 2016-08-05 09:48:22 -04:00
arc ARC: export __udivdi3 for modules 2016-08-19 14:09:33 -07:00
arm Staging/IIO driver fixes for 4.8-rc5 2016-09-03 11:33:33 -07:00
arm64 - arm64 fix: debug exception unmasking on the CPU resume path 2016-09-03 12:31:37 -07:00
avr32 dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
blackfin net: smc91x: fix SMC accesses 2016-08-28 23:44:55 -04:00
c6x dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
cris dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
frv RTC for 4.8 2016-08-05 09:48:22 -04:00
h8300 h8300: Add missing include file to asm/io.h 2016-08-13 08:53:56 -07:00
hexagon dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
ia64 Implements HARDENED_USERCOPY verification of copy_to_user/copy_from_user 2016-08-08 14:48:14 -07:00
m32r mm: do not pass mm_struct into handle_mm_fault 2016-07-26 16:19:19 -07:00
m68k m68knommu: fix user a5 register being overwritten 2016-08-08 12:38:47 +10:00
metag metag: Drop show_mem() from mem_init() 2016-08-09 13:41:30 +01:00
microblaze dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
mips * ARM fixes: 2016-08-27 15:51:50 -07:00
mn10300 RTC for 4.8 2016-08-05 09:48:22 -04:00
nios2 dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
openrisc dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
parisc mm/usercopy: get rid of CONFIG_DEBUG_STRICT_USER_COPY_CHECKS 2016-08-30 10:10:21 -07:00
powerpc powerpc: signals: Discard transaction state from signal frames 2016-08-29 12:48:40 +10:00
s390 mm/usercopy: get rid of CONFIG_DEBUG_STRICT_USER_COPY_CHECKS 2016-08-30 10:10:21 -07:00
score treewide: replace obsolete _refok by __ref 2016-08-02 17:31:41 -04:00
sh These changes improve device tree support (including builtin DTB), add 2016-08-06 09:00:05 -04:00
sparc Implements HARDENED_USERCOPY verification of copy_to_user/copy_from_user 2016-08-08 14:48:14 -07:00
tile mm/usercopy: get rid of CONFIG_DEBUG_STRICT_USER_COPY_CHECKS 2016-08-30 10:10:21 -07:00
um um: Don't discard .text.exit section 2016-08-23 23:16:16 +02:00
unicore32 unicore32: mm: Add missing parameter to arch_vma_access_permitted 2016-08-13 08:53:18 -07:00
x86 efi: Allow drivers to reserve boot services forever 2016-09-09 16:08:34 +01:00
xtensa dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
.gitignore
Kconfig Implements HARDENED_USERCOPY verification of copy_to_user/copy_from_user 2016-08-08 14:48:14 -07:00