From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757366AbYIGWY4 (ORCPT ); Sun, 7 Sep 2008 18:24:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755679AbYIGWYQ (ORCPT ); Sun, 7 Sep 2008 18:24:16 -0400 Received: from gw.goop.org ([64.81.55.164]:39650 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753091AbYIGWYO (ORCPT ); Sun, 7 Sep 2008 18:24:14 -0400 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [PATCH 1 of 7] x86: add _PAGE_IOMAP pte flag for IO mappings X-Mercurial-Node: 4d93ba619c716c45cca0b7042e4a4e493608917c Message-Id: <4d93ba619c716c45cca0.1220826073@localhost> In-Reply-To: Date: Sun, 07 Sep 2008 15:21:13 -0700 From: Jeremy Fitzhardinge To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, "H. Peter Anvin" , Xen Devel , Andi Kleen Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Use one of the software-defined PTE bits to indicate that a mapping is intended for an IO address. On native hardware this is irrelevent, since a physical address is a physical address. But in a virtual environment, physical addresses are also virtualized, so there needs to be some way to distinguish between pseudo-physical addresses and actual hardware addresses; _PAGE_IOMAP indicates this intent. By default, __supported_pte_mask masks out _PAGE_IOMAP, so it doesn't even appear in the final pagetable. Signed-off-by: Jeremy Fitzhardinge --- arch/x86/mm/init_32.c | 2 +- arch/x86/mm/init_64.c | 2 +- arch/x86/mm/ioremap.c | 8 ++++---- include/asm-x86/fixmap.h | 2 +- include/asm-x86/pgtable.h | 14 ++++++++++++-- 5 files changed, 19 insertions(+), 9 deletions(-) diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c --- a/arch/x86/mm/init_32.c +++ b/arch/x86/mm/init_32.c @@ -503,7 +503,7 @@ int nx_enabled; -pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL); +pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL | _PAGE_IOMAP); EXPORT_SYMBOL_GPL(__supported_pte_mask); #ifdef CONFIG_X86_PAE diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -88,7 +88,7 @@ int after_bootmem; -unsigned long __supported_pte_mask __read_mostly = ~0UL; +pteval_t __supported_pte_mask __read_mostly = ~_PAGE_IOMAP; EXPORT_SYMBOL_GPL(__supported_pte_mask); static int do_not_nx __cpuinitdata; diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -223,16 +223,16 @@ switch (prot_val) { case _PAGE_CACHE_UC: default: - prot = PAGE_KERNEL_NOCACHE; + prot = PAGE_KERNEL_IO_NOCACHE; break; case _PAGE_CACHE_UC_MINUS: - prot = PAGE_KERNEL_UC_MINUS; + prot = PAGE_KERNEL_IO_UC_MINUS; break; case _PAGE_CACHE_WC: - prot = PAGE_KERNEL_WC; + prot = PAGE_KERNEL_IO_WC; break; case _PAGE_CACHE_WB: - prot = PAGE_KERNEL; + prot = PAGE_KERNEL_IO; break; } diff --git a/include/asm-x86/pgtable.h b/include/asm-x86/pgtable.h --- a/include/asm-x86/pgtable.h +++ b/include/asm-x86/pgtable.h @@ -15,7 +15,7 @@ #define _PAGE_BIT_PAT 7 /* on 4KB pages */ #define _PAGE_BIT_GLOBAL 8 /* Global TLB entry PPro+ */ #define _PAGE_BIT_UNUSED1 9 /* available for programmer */ -#define _PAGE_BIT_UNUSED2 10 +#define _PAGE_BIT_IOMAP 10 /* flag used to indicate IO mapping */ #define _PAGE_BIT_HIDDEN 11 /* hidden by kmemcheck */ #define _PAGE_BIT_PAT_LARGE 12 /* On 2MB or 1GB pages */ #define _PAGE_BIT_SPECIAL _PAGE_BIT_UNUSED1 @@ -32,7 +32,7 @@ #define _PAGE_PSE (_AT(pteval_t, 1) << _PAGE_BIT_PSE) #define _PAGE_GLOBAL (_AT(pteval_t, 1) << _PAGE_BIT_GLOBAL) #define _PAGE_UNUSED1 (_AT(pteval_t, 1) << _PAGE_BIT_UNUSED1) -#define _PAGE_UNUSED2 (_AT(pteval_t, 1) << _PAGE_BIT_UNUSED2) +#define _PAGE_IOMAP (_AT(pteval_t, 1) << _PAGE_BIT_IOMAP) #define _PAGE_HIDDEN (_AT(pteval_t, 1) << _PAGE_BIT_HIDDEN) #define _PAGE_PAT (_AT(pteval_t, 1) << _PAGE_BIT_PAT) #define _PAGE_PAT_LARGE (_AT(pteval_t, 1) << _PAGE_BIT_PAT_LARGE) @@ -99,6 +99,11 @@ #define __PAGE_KERNEL_LARGE_NOCACHE (__PAGE_KERNEL | _PAGE_CACHE_UC | _PAGE_PSE) #define __PAGE_KERNEL_LARGE_EXEC (__PAGE_KERNEL_EXEC | _PAGE_PSE) +#define __PAGE_KERNEL_IO (__PAGE_KERNEL | _PAGE_IOMAP) +#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 __pgprot(__PAGE_KERNEL) #define PAGE_KERNEL_RO __pgprot(__PAGE_KERNEL_RO) #define PAGE_KERNEL_EXEC __pgprot(__PAGE_KERNEL_EXEC) @@ -112,6 +117,11 @@ #define PAGE_KERNEL_LARGE_EXEC __pgprot(__PAGE_KERNEL_LARGE_EXEC) #define PAGE_KERNEL_VSYSCALL __pgprot(__PAGE_KERNEL_VSYSCALL) #define PAGE_KERNEL_VSYSCALL_NOCACHE __pgprot(__PAGE_KERNEL_VSYSCALL_NOCACHE) + +#define PAGE_KERNEL_IO __pgprot(__PAGE_KERNEL_IO) +#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) /* xwr */ #define __P000 PAGE_NONE