From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f43.google.com (mail-wg0-f43.google.com [74.125.82.43]) by kanga.kvack.org (Postfix) with ESMTP id 1C9996B02D4 for ; Tue, 21 Jul 2015 00:49:08 -0400 (EDT) Received: by wgav7 with SMTP id v7so80442609wga.2 for ; Mon, 20 Jul 2015 21:49:07 -0700 (PDT) Received: from mx2.suse.de (cantor2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id he1si16952120wib.34.2015.07.20.21.49.05 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 20 Jul 2015 21:49:06 -0700 (PDT) Subject: Re: [Patch V6 12/16] mm: provide early_memremap_ro to establish read-only mapping References: <1437108697-4115-1-git-send-email-jgross@suse.com> <1437108697-4115-13-git-send-email-jgross@suse.com> From: Juergen Gross Message-ID: <55ADCF40.6010903@suse.com> Date: Tue, 21 Jul 2015 06:49:04 +0200 MIME-Version: 1.0 In-Reply-To: <1437108697-4115-13-git-send-email-jgross@suse.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org, Arnd Bergmann , linux-mm@kvack.org, linux-arch@vger.kernel.org Cc: xen-devel@lists.xensource.com, konrad.wilk@oracle.com, david.vrabel@citrix.com, boris.ostrovsky@oracle.com Hi MM maintainers, this patch is the last requiring an ack for the series to go in. Could you please comment? Juergen On 07/17/2015 06:51 AM, Juergen Gross wrote: > 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 > Acked-by: Konrad Rzeszutek Wilk > Cc: Arnd Bergmann > Cc: linux-mm@kvack.org > Cc: linux-arch@vger.kernel.org > --- > include/asm-generic/early_ioremap.h | 2 ++ > include/asm-generic/fixmap.h | 3 +++ > mm/early_ioremap.c | 12 ++++++++++++ > 3 files changed, 17 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..1cbb833 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 > +#if !defined(FIXMAP_PAGE_RO) && defined(PAGE_KERNEL_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..0cfadaf 100644 > --- a/mm/early_ioremap.c > +++ b/mm/early_ioremap.c > @@ -217,6 +217,13 @@ early_memremap(resource_size_t phys_addr, unsigned long size) > return (__force void *)__early_ioremap(phys_addr, size, > FIXMAP_PAGE_NORMAL); > } > +#ifdef FIXMAP_PAGE_RO > +void __init * > +early_memremap_ro(resource_size_t phys_addr, unsigned long size) > +{ > + return (__force void *)__early_ioremap(phys_addr, size, FIXMAP_PAGE_RO); > +} > +#endif > #else /* CONFIG_MMU */ > > void __init __iomem * > @@ -231,6 +238,11 @@ 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) > { > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org