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author | Ard Biesheuvel <ardb@kernel.org> | 2020-01-03 12:39:42 +0100 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2020-01-10 18:55:02 +0100 |
commit | e5f930fe8dafd2055220c95958926af16ee20713 (patch) | |
tree | 9f6c51bdecd6b109e2a004ef9213343975018a72 /arch/x86/platform/uv/bios_uv.c | |
parent | efi/x86: Simplify i386 efi_call_phys() firmware call wrapper (diff) | |
download | linux-dev-e5f930fe8dafd2055220c95958926af16ee20713.tar.xz linux-dev-e5f930fe8dafd2055220c95958926af16ee20713.zip |
efi/x86: Simplify 64-bit EFI firmware call wrapper
The efi_call() wrapper used to invoke EFI runtime services serves
a number of purposes:
- realign the stack to 16 bytes
- preserve FP and CR0 register state
- translate from SysV to MS calling convention.
Preserving CR0.TS is no longer necessary in Linux, and preserving the
FP register state is also redundant in most cases, since efi_call() is
almost always used from within the scope of a pair of kernel_fpu_begin()/
kernel_fpu_end() calls, with the exception of the early call to
SetVirtualAddressMap() and the SGI UV support code.
So let's add a pair of kernel_fpu_begin()/_end() calls there as well,
and remove the unnecessary code from the assembly implementation of
efi_call(), and only keep the pieces that deal with the stack
alignment and the ABI translation.
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/20200103113953.9571-10-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/platform/uv/bios_uv.c')
-rw-r--r-- | arch/x86/platform/uv/bios_uv.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/x86/platform/uv/bios_uv.c b/arch/x86/platform/uv/bios_uv.c index ece9cb9c1189..5c0e2eb5d87c 100644 --- a/arch/x86/platform/uv/bios_uv.c +++ b/arch/x86/platform/uv/bios_uv.c @@ -34,10 +34,13 @@ static s64 __uv_bios_call(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3, * If EFI_OLD_MEMMAP is set, we need to fall back to using our old EFI * callback method, which uses efi_call() directly, with the kernel page tables: */ - if (unlikely(efi_enabled(EFI_OLD_MEMMAP))) + if (unlikely(efi_enabled(EFI_OLD_MEMMAP))) { + kernel_fpu_begin(); ret = efi_call((void *)__va(tab->function), (u64)which, a1, a2, a3, a4, a5); - else + kernel_fpu_end(); + } else { ret = efi_call_virt_pointer(tab, function, (u64)which, a1, a2, a3, a4, a5); + } return ret; } |