linux/arch/x86/platform
Ard Biesheuvel ea5e1919b4 efi/x86: Simplify mixed mode call wrapper
Calling 32-bit EFI runtime services from a 64-bit OS involves
switching back to the flat mapping with a stack carved out of
memory that is 32-bit addressable.

There is no need to actually execute the 64-bit part of this
routine from the flat mapping as well, as long as the entry
and return address fit in 32 bits. There is also no need to
preserve part of the calling context in global variables: we
can simply push the old stack pointer value to the new stack,
and keep the return address from the code32 section in EBX.

While at it, move the conditional check whether to invoke
the mixed mode version of SetVirtualAddressMap() into the
64-bit implementation of the wrapper routine.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Matthew Garrett <mjg59@google.com>
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20200103113953.9571-11-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-01-10 18:55:03 +01:00
..
atom Driver Core and debugfs changes for 5.3-rc1 2019-07-12 12:24:03 -07:00
ce4100 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
efi efi/x86: Simplify mixed mode call wrapper 2020-01-10 18:55:03 +01:00
geode Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-07-08 17:49:45 -07:00
goldfish treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282 2019-06-05 17:36:37 +02:00
intel x86/platform/intel/iosf_mbi Rewrite locking 2019-08-19 20:52:39 +02:00
intel-mid treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
intel-quark x86: platform: no need to check return value of debugfs_create functions 2019-06-03 16:18:12 +02:00
iris treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 70 2019-05-24 17:36:47 +02:00
olpc - Core Frameworks 2019-12-01 16:16:31 -08:00
pvh x86/asm: Make some functions local 2019-10-18 11:34:39 +02:00
scx200 treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
sfi x86: Use pr_warn instead of pr_warning 2019-10-18 15:00:18 +02:00
ts5500 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
uv efi/x86: Simplify 64-bit EFI firmware call wrapper 2020-01-10 18:55:02 +01:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00