Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933727AbaGOTqy (ORCPT ); Tue, 15 Jul 2014 15:46:54 -0400 Received: from g9t1613g.houston.hp.com ([15.240.0.71]:38549 "EHLO g9t1613g.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933671AbaGOTpo (ORCPT ); Tue, 15 Jul 2014 15:45:44 -0400 From: Toshi Kani To: hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com, akpm@linux-foundation.org, arnd@arndb.de, konrad.wilk@oracle.com, plagnioj@jcrosoft.com, tomi.valkeinen@ti.com Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, stefan.bader@canonical.com, luto@amacapital.net, airlied@gmail.com, bp@alien8.de, Toshi Kani Subject: [RFC PATCH 2/11] x86, mm, pat: Define _PAGE_CACHE_WT for PA3/7 of PAT Date: Tue, 15 Jul 2014 13:34:35 -0600 Message-Id: <1405452884-25688-3-git-send-email-toshi.kani@hp.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1405452884-25688-1-git-send-email-toshi.kani@hp.com> References: <1405452884-25688-1-git-send-email-toshi.kani@hp.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch defines _PAGE_CACHE_WT and its relevant macros, which now use the PA3/7 slot in the PAT MSR. pat_init() is also changed to set the WT memory type to the PA3/7 slot in the PAT MSR. Signed-off-by: Toshi Kani --- arch/x86/include/asm/pgtable_types.h | 5 +++++ arch/x86/mm/pat.c | 8 ++++---- 2 files changed, 9 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index 03d40da..7b905cb 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -132,6 +132,7 @@ #define _PAGE_CACHE_MASK (_PAGE_PCD | _PAGE_PWT) #define _PAGE_CACHE_WB (0) #define _PAGE_CACHE_WC (_PAGE_PWT) +#define _PAGE_CACHE_WT (_PAGE_PCD | _PAGE_PWT) #define _PAGE_CACHE_UC_MINUS (_PAGE_PCD) #define _PAGE_CACHE_UC (_PAGE_CACHE_UC_MINUS) @@ -159,6 +160,7 @@ #define __PAGE_KERNEL_RX (__PAGE_KERNEL_EXEC & ~_PAGE_RW) #define __PAGE_KERNEL_EXEC_NOCACHE (__PAGE_KERNEL_EXEC | _PAGE_CACHE_UC) #define __PAGE_KERNEL_WC (__PAGE_KERNEL | _PAGE_CACHE_WC) +#define __PAGE_KERNEL_WT (__PAGE_KERNEL | _PAGE_CACHE_WT) #define __PAGE_KERNEL_NOCACHE (__PAGE_KERNEL | _PAGE_CACHE_UC) #define __PAGE_KERNEL_UC_MINUS (__PAGE_KERNEL | _PAGE_CACHE_UC_MINUS) #define __PAGE_KERNEL_VSYSCALL (__PAGE_KERNEL_RX | _PAGE_USER) @@ -172,12 +174,14 @@ #define __PAGE_KERNEL_IO_NOCACHE (__PAGE_KERNEL_NOCACHE | _PAGE_IOMAP) #define __PAGE_KERNEL_IO_UC_MINUS (__PAGE_KERNEL_UC_MINUS | _PAGE_IOMAP) #define __PAGE_KERNEL_IO_WC (__PAGE_KERNEL_WC | _PAGE_IOMAP) +#define __PAGE_KERNEL_IO_WT (__PAGE_KERNEL_WT | _PAGE_IOMAP) #define PAGE_KERNEL __pgprot(__PAGE_KERNEL) #define PAGE_KERNEL_RO __pgprot(__PAGE_KERNEL_RO) #define PAGE_KERNEL_EXEC __pgprot(__PAGE_KERNEL_EXEC) #define PAGE_KERNEL_RX __pgprot(__PAGE_KERNEL_RX) #define PAGE_KERNEL_WC __pgprot(__PAGE_KERNEL_WC) +#define PAGE_KERNEL_WT __pgprot(__PAGE_KERNEL_WT) #define PAGE_KERNEL_NOCACHE __pgprot(__PAGE_KERNEL_NOCACHE) #define PAGE_KERNEL_UC_MINUS __pgprot(__PAGE_KERNEL_UC_MINUS) #define PAGE_KERNEL_EXEC_NOCACHE __pgprot(__PAGE_KERNEL_EXEC_NOCACHE) @@ -192,6 +196,7 @@ #define PAGE_KERNEL_IO_NOCACHE __pgprot(__PAGE_KERNEL_IO_NOCACHE) #define PAGE_KERNEL_IO_UC_MINUS __pgprot(__PAGE_KERNEL_IO_UC_MINUS) #define PAGE_KERNEL_IO_WC __pgprot(__PAGE_KERNEL_IO_WC) +#define PAGE_KERNEL_IO_WT __pgprot(__PAGE_KERNEL_IO_WT) /* xwr */ #define __P000 PAGE_NONE diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index c3567a5..176d4d6 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -101,7 +101,7 @@ void pat_init(void) } } - /* Set PWT to Write-Combining. All other bits stay the same */ + /* Set PWT to Write-Combining, and PCD|PWT to Write-Through. */ /* * PTE encoding used in Linux: * PAT @@ -111,11 +111,11 @@ void pat_init(void) * 000 WB _PAGE_CACHE_WB * 001 WC _PAGE_CACHE_WC * 010 UC- _PAGE_CACHE_UC_MINUS - * 011 UC _PAGE_CACHE_UC + * 011 WT _PAGE_CACHE_WT * PAT bit unused */ - pat = PAT(0, WB) | PAT(1, WC) | PAT(2, UC_MINUS) | PAT(3, UC) | - PAT(4, WB) | PAT(5, WC) | PAT(6, UC_MINUS) | PAT(7, UC); + pat = PAT(0, WB) | PAT(1, WC) | PAT(2, UC_MINUS) | PAT(3, WT) | + PAT(4, WB) | PAT(5, WC) | PAT(6, UC_MINUS) | PAT(7, WT); /* Boot CPU check */ if (!boot_pat_state) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/