From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965176AbbLOQ7X (ORCPT ); Tue, 15 Dec 2015 11:59:23 -0500 Received: from g4t3426.houston.hp.com ([15.201.208.54]:31041 "EHLO g4t3426.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751121AbbLOQ7V (ORCPT ); Tue, 15 Dec 2015 11:59:21 -0500 From: Toshi Kani To: rjw@rjwysocki.net, dan.j.williams@intel.com Cc: elliott@hpe.com, linux-nvdimm@ml01.01.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, Toshi Kani Subject: [PATCH RESEND] ACPI/Kconfig: Make ACPI_NFIT depend on EFI_STUB on X86 Date: Tue, 15 Dec 2015 09:59:06 -0700 Message-Id: <1450198746-14161-1-git-send-email-toshi.kani@hpe.com> X-Mailer: git-send-email 2.4.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ACPI 6.0 defines NFIT table and new persistent memory types for EFI memory table (EFI_PERSISTENT_MEMORY) and e820 table (E820_PMEM). setup_e820() enabled by EFI_STUB converts EFI_PERSISTENT_MEMORY to E820_PMEM for the e820_map table on x86 EFI platforms. When EFI_STUB is disabled, x86 kernels rely on the bootloader to perform this conversion. It was found that the upstream grub bootloader since 2012 has a bug that converts EFI_PERSISTENT_MEMORY (or any new type) to E820_RAM, which causes the kernel to use persistent memory ranges as regular memory and corrupts the data in NVDIMM. Therefore, this patch sets ACPI_NFIT to depend on EFI_STUB on x86. This assures that ACPI_NFIT kernels are self-contained and are protected from the upstream grub bug on x86. Note, X86_PMEM_LEGACY allows the kernel to use the pmem driver on pre-ACPI 6.0 platforms, and does not require ACPI_NFIT enabled. References: http://www.mail-archive.com/grub-devel@gnu.org/msg23961.html Reported-by: Robert Elliott Signed-off-by: Toshi Kani Cc: Rafael J. Wysocki Cc: Dan Williams --- drivers/acpi/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index 5eef4cb..5368baa 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -441,6 +441,7 @@ config ACPI_NFIT depends on PHYS_ADDR_T_64BIT depends on BLK_DEV depends on ARCH_HAS_MMIO_FLUSH + depends on !X86 || (X86 && EFI_STUB) select LIBNVDIMM help Infrastructure to probe ACPI 6 compliant platforms for