From patchwork Wed May 13 21:05:48 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Toshi Kani X-Patchwork-Id: 6400301 Return-Path: X-Original-To: patchwork-linux-nvdimm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 7C5EC9F374 for ; Wed, 13 May 2015 21:25:40 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 7A0B32041A for ; Wed, 13 May 2015 21:25:39 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EACFB2042B for ; Wed, 13 May 2015 21:25:37 +0000 (UTC) Received: from ml01.vlan14.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id DAD021826AC; Wed, 13 May 2015 14:25:37 -0700 (PDT) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received: from g9t5009.houston.hp.com (g9t5009.houston.hp.com [15.240.92.67]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id B496E18269C for ; Wed, 13 May 2015 14:25:36 -0700 (PDT) Received: from g4t3433.houston.hp.com (g4t3433.houston.hp.com [16.210.25.219]) by g9t5009.houston.hp.com (Postfix) with ESMTP id 0DAC810E; Wed, 13 May 2015 21:25:36 +0000 (UTC) Received: from misato.fc.hp.com (misato.fc.hp.com [16.78.168.61]) by g4t3433.houston.hp.com (Postfix) with ESMTP id 9DB2C7A; Wed, 13 May 2015 21:25:34 +0000 (UTC) From: Toshi Kani To: hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com, akpm@linux-foundation.org, arnd@arndb.de Subject: [PATCH v9 7/10] x86, mm, asm: Add WT support to set_page_memtype() Date: Wed, 13 May 2015 15:05:48 -0600 Message-Id: <1431551151-19124-8-git-send-email-toshi.kani@hp.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1431551151-19124-1-git-send-email-toshi.kani@hp.com> References: <1431551151-19124-1-git-send-email-toshi.kani@hp.com> Cc: jgross@suse.com, konrad.wilk@oracle.com, linux-nvdimm@lists.01.org, mcgrof@suse.com, x86@kernel.org, linux-kernel@vger.kernel.org, stefan.bader@canonical.com, luto@amacapital.net, linux-mm@kvack.org, hmh@hmh.eng.br, hch@lst.de X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP As set_memory_wb() calls free_ram_pages_type(), which then calls set_page_memtype() with -1, _PGMT_DEFAULT is used for tracking the WB type. _PGMT_WB is defined but unused. Hence, this patch renames _PGMT_DEFAULT to _PGMT_WB to clarify the usage, and releases the slot used by _PGMT_WB before. free_ram_pages_type() is changed to call set_page_memtype() with _PGMT_WB, and get_page_memtype() returns _PAGE_CACHE_MODE_WB for _PGMT_WB. This patch then defines _PGMT_WT to the released slot. This enables set_page_memtype() to track the WT type. Signed-off-by: Toshi Kani --- arch/x86/mm/pat.c | 48 +++++++++++++++++++++--------------------------- 1 file changed, 21 insertions(+), 27 deletions(-) diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index aee5cdf..ed191e0 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -69,18 +69,18 @@ static u64 __read_mostly boot_pat_state; #ifdef CONFIG_X86_PAT /* - * X86 PAT uses page flags WC and Uncached together to keep track of - * memory type of pages that have backing page struct. X86 PAT supports 3 - * different memory types, _PAGE_CACHE_MODE_WB, _PAGE_CACHE_MODE_WC and - * _PAGE_CACHE_MODE_UC_MINUS and fourth state where page's memory type has not - * been changed from its default (value of -1 used to denote this). + * X86 PAT uses page flags arch_1 and uncached together to keep track of + * memory type of pages that have backing page struct. X86 PAT supports 4 + * different memory types, _PAGE_CACHE_MODE_WT, _PAGE_CACHE_MODE_WC, + * _PAGE_CACHE_MODE_UC_MINUS and _PAGE_CACHE_MODE_WB where page's memory + * type has not been changed from its default. * Note we do not support _PAGE_CACHE_MODE_UC here. */ -#define _PGMT_DEFAULT 0 +#define _PGMT_WB 0 /* default */ #define _PGMT_WC (1UL << PG_arch_1) #define _PGMT_UC_MINUS (1UL << PG_uncached) -#define _PGMT_WB (1UL << PG_uncached | 1UL << PG_arch_1) +#define _PGMT_WT (1UL << PG_uncached | 1UL << PG_arch_1) #define _PGMT_MASK (1UL << PG_uncached | 1UL << PG_arch_1) #define _PGMT_CLEAR_MASK (~_PGMT_MASK) @@ -88,14 +88,14 @@ static inline enum page_cache_mode get_page_memtype(struct page *pg) { unsigned long pg_flags = pg->flags & _PGMT_MASK; - if (pg_flags == _PGMT_DEFAULT) - return -1; + if (pg_flags == _PGMT_WB) + return _PAGE_CACHE_MODE_WB; else if (pg_flags == _PGMT_WC) return _PAGE_CACHE_MODE_WC; else if (pg_flags == _PGMT_UC_MINUS) return _PAGE_CACHE_MODE_UC_MINUS; else - return _PAGE_CACHE_MODE_WB; + return _PAGE_CACHE_MODE_WT; } static inline void set_page_memtype(struct page *pg, @@ -112,11 +112,12 @@ static inline void set_page_memtype(struct page *pg, case _PAGE_CACHE_MODE_UC_MINUS: memtype_flags = _PGMT_UC_MINUS; break; - case _PAGE_CACHE_MODE_WB: - memtype_flags = _PGMT_WB; + case _PAGE_CACHE_MODE_WT: + memtype_flags = _PGMT_WT; break; + case _PAGE_CACHE_MODE_WB: default: - memtype_flags = _PGMT_DEFAULT; + memtype_flags = _PGMT_WB; /* default */ break; } @@ -365,8 +366,9 @@ static int pat_pagerange_is_ram(resource_size_t start, resource_size_t end) /* * For RAM pages, we use page flags to mark the pages with appropriate type. - * The page flags are limited to three types, WB, WC and UC-. - * WT and WP requests fail with -EINVAL, and UC gets redirected to UC-. + * The page flags are limited to four types, WB (default), WC, WT and UC-. + * WP request fails with -EINVAL, and UC gets redirected to UC-. + * A new memtype can only be set to the default memtype WB. * Here we do two pass: * - Find the memtype of all the pages in the range, look for any conflicts * - In case of no conflicts, set the new memtype for pages in the range @@ -378,8 +380,7 @@ static int reserve_ram_pages_type(u64 start, u64 end, struct page *page; u64 pfn; - if ((req_type == _PAGE_CACHE_MODE_WT) || - (req_type == _PAGE_CACHE_MODE_WP)) { + if (req_type == _PAGE_CACHE_MODE_WP) { if (new_type) *new_type = _PAGE_CACHE_MODE_UC_MINUS; return -EINVAL; @@ -396,7 +397,7 @@ static int reserve_ram_pages_type(u64 start, u64 end, page = pfn_to_page(pfn); type = get_page_memtype(page); - if (type != -1) { + if (type != _PAGE_CACHE_MODE_WB) { pr_info("reserve_ram_pages_type failed [mem %#010Lx-%#010Lx], track 0x%x, req 0x%x\n", start, end - 1, type, req_type); if (new_type) @@ -423,7 +424,7 @@ static int free_ram_pages_type(u64 start, u64 end) for (pfn = (start >> PAGE_SHIFT); pfn < (end >> PAGE_SHIFT); ++pfn) { page = pfn_to_page(pfn); - set_page_memtype(page, -1); + set_page_memtype(page, _PAGE_CACHE_MODE_WB); } return 0; } @@ -568,7 +569,7 @@ int free_memtype(u64 start, u64 end) * Only to be called when PAT is enabled * * Returns _PAGE_CACHE_MODE_WB, _PAGE_CACHE_MODE_WC, _PAGE_CACHE_MODE_UC_MINUS - * or _PAGE_CACHE_MODE_UC + * or _PAGE_CACHE_MODE_WT. */ static enum page_cache_mode lookup_memtype(u64 paddr) { @@ -582,13 +583,6 @@ static enum page_cache_mode lookup_memtype(u64 paddr) struct page *page; page = pfn_to_page(paddr >> PAGE_SHIFT); rettype = get_page_memtype(page); - /* - * -1 from get_page_memtype() implies RAM page is in its - * default state and not reserved, and hence of type WB - */ - if (rettype == -1) - rettype = _PAGE_CACHE_MODE_WB; - return rettype; }