Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932194AbbFHMJM (ORCPT ); Mon, 8 Jun 2015 08:09:12 -0400 Received: from cantor2.suse.de ([195.135.220.15]:43137 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752195AbbFHMHG (ORCPT ); Mon, 8 Jun 2015 08:07:06 -0400 From: Juergen Gross To: xen-devel@lists.xensource.com, konrad.wilk@oracle.com, david.vrabel@citrix.com, boris.ostrovsky@oracle.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Juergen Gross Subject: [Patch V4 12/16] mm: provide early_memremap_ro to establish read-only mapping Date: Mon, 8 Jun 2015 14:06:53 +0200 Message-Id: <1433765217-16333-13-git-send-email-jgross@suse.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1433765217-16333-1-git-send-email-jgross@suse.com> References: <1433765217-16333-1-git-send-email-jgross@suse.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2778 Lines: 79 During early boot as Xen pv domain the kernel needs to map some page tables supplied by the hypervisor read only. This is needed to be able to relocate some data structures conflicting with the physical memory map especially on systems with huge RAM (above 512GB). Provide the function early_memremap_ro() to provide this read only mapping. Signed-off-by: Juergen Gross --- include/asm-generic/early_ioremap.h | 2 ++ include/asm-generic/fixmap.h | 3 +++ mm/early_ioremap.c | 11 +++++++++++ 3 files changed, 16 insertions(+) diff --git a/include/asm-generic/early_ioremap.h b/include/asm-generic/early_ioremap.h index a5de55c..316bd04 100644 --- a/include/asm-generic/early_ioremap.h +++ b/include/asm-generic/early_ioremap.h @@ -11,6 +11,8 @@ extern void __iomem *early_ioremap(resource_size_t phys_addr, unsigned long size); extern void *early_memremap(resource_size_t phys_addr, unsigned long size); +extern void *early_memremap_ro(resource_size_t phys_addr, + unsigned long size); extern void early_iounmap(void __iomem *addr, unsigned long size); extern void early_memunmap(void *addr, unsigned long size); diff --git a/include/asm-generic/fixmap.h b/include/asm-generic/fixmap.h index f23174f..d8cc637 100644 --- a/include/asm-generic/fixmap.h +++ b/include/asm-generic/fixmap.h @@ -46,6 +46,9 @@ static inline unsigned long virt_to_fix(const unsigned long vaddr) #ifndef FIXMAP_PAGE_NORMAL #define FIXMAP_PAGE_NORMAL PAGE_KERNEL #endif +#ifndef FIXMAP_PAGE_RO +#define FIXMAP_PAGE_RO PAGE_KERNEL_RO +#endif #ifndef FIXMAP_PAGE_NOCACHE #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NOCACHE #endif diff --git a/mm/early_ioremap.c b/mm/early_ioremap.c index e10ccd2..e4ffaac 100644 --- a/mm/early_ioremap.c +++ b/mm/early_ioremap.c @@ -217,6 +217,12 @@ early_memremap(resource_size_t phys_addr, unsigned long size) return (__force void *)__early_ioremap(phys_addr, size, FIXMAP_PAGE_NORMAL); } +void __init * +early_memremap_ro(resource_size_t phys_addr, unsigned long size) +{ + return (__force void *)__early_ioremap(phys_addr, size, + FIXMAP_PAGE_RO); +} #else /* CONFIG_MMU */ void __init __iomem * @@ -231,6 +237,11 @@ early_memremap(resource_size_t phys_addr, unsigned long size) { return (void *)phys_addr; } +void __init * +early_memremap_ro(resource_size_t phys_addr, unsigned long size) +{ + return (void *)phys_addr; +} void __init early_iounmap(void __iomem *addr, unsigned long size) { -- 2.1.4 -- 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/