From patchwork Mon Feb 1 18:00:51 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Lutomirski X-Patchwork-Id: 8182531 Return-Path: X-Original-To: patchwork-xen-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 09325BEEED for ; Mon, 1 Feb 2016 18:03:44 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 1D6A92034E for ; Mon, 1 Feb 2016 18:03:43 +0000 (UTC) Received: from lists.xen.org (lists.xenproject.org [50.57.142.19]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2B305203A1 for ; Mon, 1 Feb 2016 18:03:42 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xen.org) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1aQImj-0007jZ-Uz; Mon, 01 Feb 2016 18:01:09 +0000 Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1aQImi-0007jF-Ea for xen-devel@lists.xenproject.org; Mon, 01 Feb 2016 18:01:08 +0000 Received: from [85.158.137.68] by server-16.bemta-3.messagelabs.com id DC/49-07451-36D9FA65; Mon, 01 Feb 2016 18:01:07 +0000 X-Env-Sender: luto@kernel.org X-Msg-Ref: server-14.tower-31.messagelabs.com!1454349665!19568654!1 X-Originating-IP: [198.145.29.136] X-SpamReason: No, hits=0.0 required=7.0 tests= X-StarScan-Received: X-StarScan-Version: 7.35.1; banners=-,-,- X-VirusChecked: Checked Received: (qmail 18007 invoked from network); 1 Feb 2016 18:01:06 -0000 Received: from mail.kernel.org (HELO mail.kernel.org) (198.145.29.136) by server-14.tower-31.messagelabs.com with SMTP; 1 Feb 2016 18:01:06 -0000 Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id B0DCF2034E; Mon, 1 Feb 2016 18:01:04 +0000 (UTC) Received: from localhost (c-71-202-137-17.hsd1.ca.comcast.net [71.202.137.17]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D29D320340; Mon, 1 Feb 2016 18:01:03 +0000 (UTC) From: Andy Lutomirski To: "Michael S. Tsirkin" Date: Mon, 1 Feb 2016 10:00:51 -0800 Message-Id: <6973e55a7ae955d7aaa94d143e84091c06bdd18f.1454349471.git.luto@kernel.org> X-Mailer: git-send-email 2.5.0 In-Reply-To: References: In-Reply-To: References: X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, 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 Cc: Cornelia Huck , Joerg Roedel , KVM , linux-s390 , Benjamin Herrenschmidt , Stefano Stabellini , Sebastian Ott , "linux-kernel@vger.kernel.org" , Christoph Hellwig , Christian Borntraeger , David Vrabel , xen-devel@lists.xenproject.org, sparclinux@vger.kernel.org, Paolo Bonzini , Linux Virtualization , David Woodhouse , "David S. Miller" , Martin Schwidefsky Subject: [Xen-devel] [PATCH v6 1/9] dma: Provide simple noop dma ops X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org X-Virus-Scanned: ClamAV using ClamSMTP From: Christian Borntraeger We are going to require dma_ops for several common drivers, even for systems that do have an identity mapping. Lets provide some minimal no-op dma_ops that can be used for that purpose. Signed-off-by: Christian Borntraeger Reviewed-by: Joerg Roedel --- include/linux/dma-mapping.h | 2 ++ lib/Makefile | 1 + lib/dma-noop.c | 75 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 78 insertions(+) create mode 100644 lib/dma-noop.c diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 75857cda38e9..c0b27ff2c784 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -70,6 +70,8 @@ struct dma_map_ops { int is_phys; }; +extern struct dma_map_ops dma_noop_ops; + #define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1)) #define DMA_MASK_NONE 0x0ULL diff --git a/lib/Makefile b/lib/Makefile index a7c26a41a738..a572b86a1b1d 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -18,6 +18,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \ obj-$(CONFIG_ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS) += usercopy.o lib-$(CONFIG_MMU) += ioremap.o lib-$(CONFIG_SMP) += cpumask.o +lib-$(CONFIG_HAS_DMA) += dma-noop.o lib-y += kobject.o klist.o obj-y += lockref.o diff --git a/lib/dma-noop.c b/lib/dma-noop.c new file mode 100644 index 000000000000..72145646857e --- /dev/null +++ b/lib/dma-noop.c @@ -0,0 +1,75 @@ +/* + * lib/dma-noop.c + * + * Simple DMA noop-ops that map 1:1 with memory + */ +#include +#include +#include +#include + +static void *dma_noop_alloc(struct device *dev, size_t size, + dma_addr_t *dma_handle, gfp_t gfp, + struct dma_attrs *attrs) +{ + void *ret; + + ret = (void *)__get_free_pages(gfp, get_order(size)); + if (ret) + *dma_handle = virt_to_phys(ret); + return ret; +} + +static void dma_noop_free(struct device *dev, size_t size, + void *cpu_addr, dma_addr_t dma_addr, + struct dma_attrs *attrs) +{ + free_pages((unsigned long)cpu_addr, get_order(size)); +} + +static dma_addr_t dma_noop_map_page(struct device *dev, struct page *page, + unsigned long offset, size_t size, + enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + return page_to_phys(page) + offset; +} + +static int dma_noop_map_sg(struct device *dev, struct scatterlist *sgl, int nents, + enum dma_data_direction dir, struct dma_attrs *attrs) +{ + int i; + struct scatterlist *sg; + + for_each_sg(sgl, sg, nents, i) { + void *va; + + BUG_ON(!sg_page(sg)); + va = sg_virt(sg); + sg_dma_address(sg) = (dma_addr_t)virt_to_phys(va); + sg_dma_len(sg) = sg->length; + } + + return nents; +} + +static int dma_noop_mapping_error(struct device *dev, dma_addr_t dma_addr) +{ + return 0; +} + +static int dma_noop_supported(struct device *dev, u64 mask) +{ + return 1; +} + +struct dma_map_ops dma_noop_ops = { + .alloc = dma_noop_alloc, + .free = dma_noop_free, + .map_page = dma_noop_map_page, + .map_sg = dma_noop_map_sg, + .mapping_error = dma_noop_mapping_error, + .dma_supported = dma_noop_supported, +}; + +EXPORT_SYMBOL(dma_noop_ops);