Patch "x86/platform/UV: Fix support for EFI_OLD_MEMMAP after BIOS callback updates" has been added to the 4.8-stable tree
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This is a note to let you know that I've just added the patch titled
x86/platform/UV: Fix support for EFI_OLD_MEMMAP after BIOS callback updates
to the 4.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-platform-uv-fix-support-for-efi_old_memmap-after-bios-callback-updates.patch
and it can be found in the queue-4.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.
Quoted 1 line
From
caef78b6cdeddf4ad364f95910bba6b43b8eb9bfMon Sep 17 00:00:00 2001
From: Alex Thorlton <[email protected]>
Date: Wed, 19 Oct 2016 20:48:51 -0500
Subject: x86/platform/UV: Fix support for EFI_OLD_MEMMAP after BIOS callback updates
From: Alex Thorlton <[email protected]>
commit caef78b6cdeddf4ad364f95910bba6b43b8eb9bf upstream.
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.
--- arch/x86/platform/uv/bios_uv.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
arch/x86/platform/uv/bios_uv.c +9 -1
@@ -40,7 +40,15 @@ s64 uv_bios_call(enum uv_bios_cmd which,*/ 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);
Patches currently in stable-queue which might be from [email protected] are
queue-4.8/x86-platform-uv-fix-support-for-efi_old_memmap-after-bios-callback-updates.patch