From patchwork Sat Jul 25 02:38:42 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 6864031 Return-Path: X-Original-To: patchwork-linux-arm@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 2D7BB9F380 for ; Sat, 25 Jul 2015 02:48:05 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 1853A20452 for ; Sat, 25 Jul 2015 02:48:04 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0705F20435 for ; Sat, 25 Jul 2015 02:48:03 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZIpTX-0002un-3H; Sat, 25 Jul 2015 02:46:11 +0000 Received: from mga03.intel.com ([134.134.136.65]) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZIpS9-0000YO-Hs for linux-arm-kernel@lists.infradead.org; Sat, 25 Jul 2015 02:44:48 +0000 Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga103.jf.intel.com with ESMTP; 24 Jul 2015 19:44:25 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.15,542,1432623600"; d="scan'208";a="754443750" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.11]) by fmsmga001.fm.intel.com with ESMTP; 24 Jul 2015 19:44:24 -0700 Subject: [PATCH v2 08/25] arch: introduce memremap() From: Dan Williams To: tglx@linutronix.de, mingo@kernel.org, hpa@zytor.com Date: Fri, 24 Jul 2015 22:38:42 -0400 Message-ID: <20150725023842.8664.97620.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <20150725023649.8664.59145.stgit@dwillia2-desk3.amr.corp.intel.com> References: <20150725023649.8664.59145.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.17.1-8-g92dd MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150724_194445_893423_8AC2AAE3 X-CRM114-Status: GOOD ( 22.16 ) X-Spam-Score: -8.1 (--------) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, toshi.kani@hp.com, Arnd Bergmann , linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, rmk+kernel@arm.linux.org.uk, hch@lst.de, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-5.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, 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 Existing users of ioremap_cache() are mapping memory that is known in advance to not have i/o side effects. These users are forced to cast away the __iomem annotation, or otherwise neglect to fix the sparse errors thrown when dereferencing pointers to this memory. Provide memremap() as a non __iomem annotated ioremap_*() in the case when ioremap is otherwise a pointer to memory. Outside of ioremap() and ioremap_nocache(), the expectation is that most calls to ioremap_() are seeking memory-like semantics (e.g. speculative reads, and prefetching permitted). These callsites can be moved to memremap() over time. memremap() is a break from the ioremap implementation pattern of adding a new memremap_() for each mapping type and having silent compatibility fall backs. Instead, the implementation defines flags that are passed to the central memremap() and if a mapping type is not supported by an arch memremap returns NULL. The behavior change to return NULL on an unsupported request is reserved for a later patch. This initial implementation starts off by using ioremap_cache() directly. Once all ioremap_cache() and ioremap_wt() instances have been converted the functionality for establishing these mappings will be pushed to a per-architecture arch_memremap() implementation. Cc: Arnd Bergmann Signed-off-by: Dan Williams --- arch/ia64/include/asm/io.h | 1 + arch/sh/include/asm/io.h | 1 + arch/xtensa/include/asm/io.h | 1 + include/linux/io.h | 9 +++++ kernel/Makefile | 2 + kernel/memremap.c | 82 ++++++++++++++++++++++++++++++++++++++++++ 6 files changed, 96 insertions(+) create mode 100644 kernel/memremap.c diff --git a/arch/ia64/include/asm/io.h b/arch/ia64/include/asm/io.h index 80a7e34be009..9041bbe2b7b4 100644 --- a/arch/ia64/include/asm/io.h +++ b/arch/ia64/include/asm/io.h @@ -435,6 +435,7 @@ static inline void __iomem * ioremap_cache (unsigned long phys_addr, unsigned lo { return ioremap(phys_addr, size); } +#define ioremap_cache ioremap_cache /* diff --git a/arch/sh/include/asm/io.h b/arch/sh/include/asm/io.h index 728c4c571f40..6194e20fccca 100644 --- a/arch/sh/include/asm/io.h +++ b/arch/sh/include/asm/io.h @@ -342,6 +342,7 @@ ioremap_cache(phys_addr_t offset, unsigned long size) { return __ioremap_mode(offset, size, PAGE_KERNEL); } +#define ioremap_cache ioremap_cache #ifdef CONFIG_HAVE_IOREMAP_PROT static inline void __iomem * diff --git a/arch/xtensa/include/asm/io.h b/arch/xtensa/include/asm/io.h index c39bb6e61911..867840f5400f 100644 --- a/arch/xtensa/include/asm/io.h +++ b/arch/xtensa/include/asm/io.h @@ -57,6 +57,7 @@ static inline void __iomem *ioremap_cache(unsigned long offset, else BUG(); } +#define ioremap_cache ioremap_cache #define ioremap_wc ioremap_nocache #define ioremap_wt ioremap_nocache diff --git a/include/linux/io.h b/include/linux/io.h index fb5a99800e77..dfed9d608bb3 100644 --- a/include/linux/io.h +++ b/include/linux/io.h @@ -121,4 +121,13 @@ static inline int arch_phys_wc_index(int handle) #endif #endif +enum { + MEMREMAP_WB = 1 << 0, + MEMREMAP_WT = 1 << 1, + MEMREMAP_CACHE = MEMREMAP_WB, +}; + +extern void *memremap(resource_size_t offset, size_t size, unsigned long flags); +extern void memunmap(void *addr); + #endif /* _LINUX_IO_H */ diff --git a/kernel/Makefile b/kernel/Makefile index 43c4c920f30a..92866d36e376 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -99,6 +99,8 @@ obj-$(CONFIG_JUMP_LABEL) += jump_label.o obj-$(CONFIG_CONTEXT_TRACKING) += context_tracking.o obj-$(CONFIG_TORTURE_TEST) += torture.o +obj-$(CONFIG_HAS_IOMEM) += memremap.o + $(obj)/configs.o: $(obj)/config_data.h # config_data.h contains the same information as ikconfig.h but gzipped. diff --git a/kernel/memremap.c b/kernel/memremap.c new file mode 100644 index 000000000000..ba206fd11785 --- /dev/null +++ b/kernel/memremap.c @@ -0,0 +1,82 @@ +/* + * Copyright(c) 2015 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ +#include +#include +#include + +#ifndef ioremap_cache +/* temporary while we convert existing ioremap_cache users to memremap */ +__weak void __iomem *ioremap_cache(resource_size_t offset, unsigned long size) +{ + return ioremap(offset, size); +} +#endif + +/* + * memremap() is "ioremap" for cases where it is known that the resource + * being mapped does not have i/o side effects and the __iomem + * annotation is not applicable. + */ +void *memremap(resource_size_t offset, size_t size, unsigned long flags) +{ + int is_ram = region_is_ram(offset, size); + void *addr = NULL; + + if (is_ram < 0) { + WARN_ONCE(1, "memremap attempted on mixed range %pa size: %zu\n", + &offset, size); + return NULL; + } + + /* Try all mapping types requested until one returns non-NULL */ + if (flags & MEMREMAP_CACHE) { + flags &= ~MEMREMAP_CACHE; + /* + * MEMREMAP_CACHE is special in that it can be satisifed + * from the direct map. Some archs depend on the + * capability of memremap() to autodetect cases where + * the requested range is potentially in "System RAM" + */ + if (is_ram) + addr = __va(offset); + else + addr = ioremap_cache(offset, size); + } + + /* + * If we don't have a mapping yet and more request flags are + * pending then we will be attempting to establish a new virtual + * address mapping. Enforce that this mapping is not aliasing + * "System RAM" + */ + if (!addr && is_ram && flags) { + WARN_ONCE(1, "memremap attempted on ram %pa size: %zu\n", + &offset, size); + return NULL; + } + + if (!addr && (flags & MEMREMAP_WT)) { + flags &= ~MEMREMAP_WT; + addr = ioremap_wt(offset, size); + } + + return addr; +} +EXPORT_SYMBOL(memremap); + +void memunmap(void *addr) +{ + if (is_vmalloc_addr(addr)) + iounmap((void __iomem *) addr); +} +EXPORT_SYMBOL(memunmap);