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x86/platform/UV: Fix support for EFI_OLD_MEMMAP after BIOS callback updates

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Some time ago, we brought our UV BIOS callback code up to speed with the
new EFI memory mapping scheme, in commit:

    d1be84a232 ("x86/uv: Update uv_bios_call() to use efi_call_virt_pointer()")

By leveraging some changes that I made to a few of the EFI runtime
callback mechanisms, in commit:

    80e7559607 ("efi: Convert efi_call_virt() to efi_call_virt_pointer()")

This got everything running smoothly on UV, with the new EFI mapping
code.  However, this left one, small loose end, in that EFI_OLD_MEMMAP
(a.k.a. efi=old_map) will no longer work on UV, on kernels that include
the aforementioned changes.

At the time this was not a major issue (in fact, it still really isn't),
but there's no reason that EFI_OLD_MEMMAP *shouldn't* work on our
systems.  This commit adds a check into uv_bios_call(), to see if we have
the EFI_OLD_MEMMAP bit set in efi.flags.  If it is set, we fall back to
using our old callback method, which uses efi_call() directly on the __va()
of our function pointer.

Signed-off-by: Alex Thorlton <athorlton@sgi.com>
Acked-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: <stable@vger.kernel.org> # v4.7 and later
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Mike Travis <travis@sgi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <rja@sgi.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1476928131-170101-1-git-send-email-athorlton@sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Alex Thorlton 2016-10-19 20:48:51 -05:00 committed by Ingo Molnar
parent 8214899342
commit caef78b6cd
1 changed files with 9 additions and 1 deletions
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10
arch/x86/platform/uv/bios_uv.c
View File

@ -40,7 +40,15 @@ s64 uv_bios_call(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3, u64 a4, u64 a5)
*/
return BIOS_STATUS_UNIMPLEMENTED;
ret = efi_call_virt_pointer(tab, function, (u64)which, a1, a2, a3, a4, a5);
/*
* 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(test_bit(EFI_OLD_MEMMAP, &efi.flags)))
ret = efi_call((void *)__va(tab->function), (u64)which, a1, a2, a3, a4, a5);
else
ret = efi_call_virt_pointer(tab, function, (u64)which, a1, a2, a3, a4, a5);
return ret;
}
EXPORT_SYMBOL_GPL(uv_bios_call);