From patchwork Fri Dec 29 08:18:54 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 10136837 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 891236037D for ; Fri, 29 Dec 2017 08:40:46 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 730DF2D9AF for ; Fri, 29 Dec 2017 08:40:46 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6654A2D938; Fri, 29 Dec 2017 08:40:46 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id F0EBD2D7ED for ; Fri, 29 Dec 2017 08:40:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=MvqNQdj1ltgTvtufLviyOxTEyr9/hvAV9HnCHfFB+Gs=; b=dShcqBjdBLCL8WuSneljQdXkOY w7rdnfIfgkYaHkd9ndfyS167OuNu6G06two3fwA+pi282cWKLNzxE6Gb2FdQXLgrbR9o95zqwBOJu 2DpYCh8I69DZt4nCe96hQwVBAahJncH22zy73Js6Dq6z6qRs0UMiObtRttFyX7Tbu5mxv/TFb2bEk /Qk/qy2f3x4I8hSGNpFIku18vw/iEea7QGNNMmwjB/vS5qcwyvCY1Xpr4pJF305RhKgJ5Jwp/T6/8 yIIy1qsntlWyYCeqQZipxwDTHn/LFd+5ERzZDkNAWPLfP2Fdb6HLtXylLvOl9rOW+IJ99YNyl/VfP LyYv+tzw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.89 #1 (Red Hat Linux)) id 1eUqDY-0000Pl-4A; Fri, 29 Dec 2017 08:40:40 +0000 Received: from 77.117.237.29.wireless.dyn.drei.com ([77.117.237.29] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.89 #1 (Red Hat Linux)) id 1eUpwM-0003IU-VO; Fri, 29 Dec 2017 08:22:55 +0000 From: Christoph Hellwig To: iommu@lists.linux-foundation.org Subject: [PATCH 50/67] swiotlb: refactor coherent buffer allocation Date: Fri, 29 Dec 2017 09:18:54 +0100 Message-Id: <20171229081911.2802-51-hch@lst.de> X-Mailer: git-send-email 2.14.2 In-Reply-To: <20171229081911.2802-1-hch@lst.de> References: <20171229081911.2802-1-hch@lst.de> X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-mips@linux-mips.org, linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, Guan Xuetao , linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, linux-c6x-dev@linux-c6x.org, linux-hexagon@vger.kernel.org, x86@kernel.org, linux-snps-arc@lists.infradead.org, adi-buildroot-devel@lists.sourceforge.net, linux-m68k@lists.linux-m68k.org, patches@groups.riscv.org, linux-metag@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Michal Simek , linux-parisc@vger.kernel.org, linux-cris-kernel@axis.com, linux-kernel@vger.kernel.org, linux-alpha@vger.kernel.org, linuxppc-dev@lists.ozlabs.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Factor out a new swiotlb_alloc_buffer helper that allocates DMA coherent memory from the swiotlb bounce buffer. This allows to simplify the swiotlb_alloc implemenation that uses dma_direct_alloc to try to allocate a reachable buffer first. Signed-off-by: Christoph Hellwig --- lib/swiotlb.c | 100 ++++++++++++++++++++++++++++++---------------------------- 1 file changed, 51 insertions(+), 49 deletions(-) diff --git a/lib/swiotlb.c b/lib/swiotlb.c index adb4dd0091fa..905eea6353a3 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -709,67 +709,69 @@ void swiotlb_tbl_sync_single(struct device *hwdev, phys_addr_t tlb_addr, } EXPORT_SYMBOL_GPL(swiotlb_tbl_sync_single); +static void * +swiotlb_alloc_buffer(struct device *dev, size_t size, dma_addr_t *dma_handle) +{ + phys_addr_t phys_addr; + + if (swiotlb_force == SWIOTLB_NO_FORCE) + goto out_warn; + + phys_addr = swiotlb_tbl_map_single(dev, + swiotlb_phys_to_dma(dev, io_tlb_start), + 0, size, DMA_FROM_DEVICE, 0); + if (phys_addr == SWIOTLB_MAP_ERROR) + goto out_warn; + + *dma_handle = swiotlb_phys_to_dma(dev, phys_addr); + + /* Confirm address can be DMA'd by device */ + if (*dma_handle + size - 1 > dev->coherent_dma_mask) + goto out_unmap; + + memset(phys_to_virt(phys_addr), 0, size); + return phys_to_virt(phys_addr); + +out_unmap: + dev_warn(dev, "hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n", + (unsigned long long)dev->coherent_dma_mask, + (unsigned long long)*dma_handle); + + /* + * DMA_TO_DEVICE to avoid memcpy in unmap_single. + * DMA_ATTR_SKIP_CPU_SYNC is optional. + */ + swiotlb_tbl_unmap_single(dev, phys_addr, size, DMA_TO_DEVICE, + DMA_ATTR_SKIP_CPU_SYNC); +out_warn: + dev_warn(dev, + "swiotlb: coherent allocation failed, size=%zu\n", size); + dump_stack(); + return NULL; +} + void * swiotlb_alloc_coherent(struct device *hwdev, size_t size, dma_addr_t *dma_handle, gfp_t flags) { - dma_addr_t dev_addr; - void *ret; int order = get_order(size); + void *ret; ret = (void *)__get_free_pages(flags, order); if (ret) { - dev_addr = swiotlb_virt_to_bus(hwdev, ret); - if (dev_addr + size - 1 > hwdev->coherent_dma_mask) { - /* - * The allocated memory isn't reachable by the device. - */ - free_pages((unsigned long) ret, order); - ret = NULL; + *dma_handle = swiotlb_virt_to_bus(hwdev, ret); + if (*dma_handle + size - 1 <= hwdev->coherent_dma_mask) { + memset(ret, 0, size); + return ret; } - } - if (!ret) { + /* - * We are either out of memory or the device can't DMA to - * GFP_DMA memory; fall back on map_single(), which - * will grab memory from the lowest available address range. + * The allocated memory isn't reachable by the device. */ - phys_addr_t paddr = map_single(hwdev, 0, size, - DMA_FROM_DEVICE, 0); - if (paddr == SWIOTLB_MAP_ERROR) - goto err_warn; - - ret = phys_to_virt(paddr); - dev_addr = swiotlb_phys_to_dma(hwdev, paddr); - - /* Confirm address can be DMA'd by device */ - if (dev_addr + size - 1 > hwdev->coherent_dma_mask) { - printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n", - (unsigned long long)hwdev->coherent_dma_mask, - (unsigned long long)dev_addr); - - /* - * DMA_TO_DEVICE to avoid memcpy in unmap_single. - * The DMA_ATTR_SKIP_CPU_SYNC is optional. - */ - swiotlb_tbl_unmap_single(hwdev, paddr, - size, DMA_TO_DEVICE, - DMA_ATTR_SKIP_CPU_SYNC); - goto err_warn; - } + free_pages((unsigned long) ret, order); } - *dma_handle = dev_addr; - memset(ret, 0, size); - - return ret; - -err_warn: - pr_warn("swiotlb: coherent allocation failed for device %s size=%zu\n", - dev_name(hwdev), size); - dump_stack(); - - return NULL; + return swiotlb_alloc_buffer(hwdev, size, dma_handle); } EXPORT_SYMBOL(swiotlb_alloc_coherent); @@ -1105,7 +1107,7 @@ void *swiotlb_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, vaddr = dma_direct_alloc(dev, size, dma_handle, gfp, attrs); if (!vaddr) - vaddr = swiotlb_alloc_coherent(dev, size, dma_handle, gfp); + vaddr = swiotlb_alloc_buffer(dev, size, dma_handle); return vaddr; }