From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg Kroah-Hartman Subject: [PATCH 4.8 104/140] x86/platform/UV: Fix support for EFI_OLD_MEMMAP after BIOS callback updates Date: Wed, 26 Oct 2016 14:22:44 +0200 Message-ID: <20161026122224.839245613@linuxfoundation.org> References: <20161026122220.384323763@linuxfoundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: In-Reply-To: <20161026122220.384323763@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alex Thorlton , Matt Fleming , Andy Lutomirski , Ard Biesheuvel , Borislav Petkov , Brian Gerst , Denys Vlasenko , Dimitri Sivanich , "H. Peter Anvin" , Josh Poimboeuf , Linus Torvalds , Masahiro Yamada , Mike Travis , Peter Zijlstra , Russ Anderson , Thomas Gleixner , linux-efi@vger.kernel.org, Ingo Molnar List-Id: linux-efi@vger.kernel.org 4.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alex Thorlton 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. Signed-off-by: Alex Thorlton Acked-by: Matt Fleming Cc: Andy Lutomirski Cc: Ard Biesheuvel Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: Dimitri Sivanich Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Masahiro Yamada Cc: Mike Travis Cc: Peter Zijlstra Cc: Russ Anderson Cc: Thomas Gleixner 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 Signed-off-by: Greg Kroah-Hartman --- arch/x86/platform/uv/bios_uv.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- 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, */ 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);