From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932492Ab1EIXRV (ORCPT ); Mon, 9 May 2011 19:17:21 -0400 Received: from hera.kernel.org ([140.211.167.34]:60086 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755115Ab1EIXRU (ORCPT ); Mon, 9 May 2011 19:17:20 -0400 Date: Mon, 9 May 2011 23:17:15 GMT From: tip-bot for Matthew Garrett Message-ID: Cc: linux-kernel@vger.kernel.org, mjg@redhat.com, hpa@zytor.com, mingo@redhat.com, tglx@linutronix.de, hpa@linux.intel.com Reply-To: mingo@redhat.com, hpa@zytor.com, mjg@redhat.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, hpa@linux.intel.com In-Reply-To: <1304623186-18261-3-git-send-email-mjg@redhat.com> References: <1304623186-18261-3-git-send-email-mjg@redhat.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/efi] x86, efi: Merge contiguous memory regions of the same type and attribute Git-Commit-ID: 202f9d0a41809e3424af5f61489b48b622824aed X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Mon, 09 May 2011 23:17:15 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 202f9d0a41809e3424af5f61489b48b622824aed Gitweb: http://git.kernel.org/tip/202f9d0a41809e3424af5f61489b48b622824aed Author: Matthew Garrett AuthorDate: Thu, 5 May 2011 15:19:44 -0400 Committer: H. Peter Anvin CommitDate: Mon, 9 May 2011 12:14:34 -0700 x86, efi: Merge contiguous memory regions of the same type and attribute Some firmware implementations assume that physically contiguous regions will be contiguous in virtual address space. This assumption is, obviously, entirely unjustifiable. Said firmware implementations lack the good grace to handle their failings in a measured and reasonable manner, instead tending to shit all over address space and oopsing the kernel. In an ideal universe these firmware implementations would simultaneously catch fire and cease to be a problem, but since some of them are present in attractively thin and shiny metal devices vanity wins out and some poor developer spends an extended period of time surrounded by a growing array of empty bottles until the underlying reason becomes apparent. Said developer presents this patch, which simply merges adjacent regions if they happen to be contiguous and have the same EFI memory type and caching attributes. Signed-off-by: Matthew Garrett Link: http://lkml.kernel.org/r/1304623186-18261-3-git-send-email-mjg@redhat.com Signed-off-by: H. Peter Anvin --- arch/x86/platform/efi/efi.c | 30 +++++++++++++++++++++++++++++- 1 files changed, 29 insertions(+), 1 deletions(-) diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index 7daae27..a46a73e 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -498,13 +498,41 @@ static void __init runtime_code_page_mkexec(void) */ void __init efi_enter_virtual_mode(void) { - efi_memory_desc_t *md; + efi_memory_desc_t *md, *prev_md = NULL; efi_status_t status; unsigned long size; u64 end, systab, addr, npages, end_pfn; void *p, *va; efi.systab = NULL; + + /* Merge contiguous regions of the same type and attribute */ + for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { + u64 prev_size; + md = p; + + if (!prev_md) { + prev_md = md; + continue; + } + + if (prev_md->type != md->type || + prev_md->attribute != md->attribute) { + prev_md = md; + continue; + } + + prev_size = prev_md->num_pages << EFI_PAGE_SHIFT; + + if (md->phys_addr == (prev_md->phys_addr + prev_size)) { + prev_md->num_pages += md->num_pages; + md->type = EFI_RESERVED_TYPE; + md->attribute = 0; + continue; + } + prev_md = md; + } + for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { md = p; if (!(md->attribute & EFI_MEMORY_RUNTIME))