Messages in this thread Patch in this message | | | From | Alex Thorlton <> | Subject | [PATCH v2] x86/platform/UV: Fix support for EFI_OLD_MEMMAP after BIOS callback updates | Date | Wed, 19 Oct 2016 20:48:51 -0500 |
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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:
d1be84a232e3 ("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:
80e75596079f ("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.
v2: Invert if-statement and add unlikely() hint.
Signed-off-by: Alex Thorlton <athorlton@sgi.com> Cc: Mike Travis <travis@sgi.com> Cc: Russ Anderson <rja@sgi.com> Cc: Dimitri Sivanich <sivanich@sgi.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: x86@kernel.org --- arch/x86/platform/uv/bios_uv.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/arch/x86/platform/uv/bios_uv.c b/arch/x86/platform/uv/bios_uv.c index b4d5e95..d1f7422 100644 --- a/arch/x86/platform/uv/bios_uv.c +++ b/arch/x86/platform/uv/bios_uv.c @@ -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); -- 1.8.5.6
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