From patchwork Mon Aug 5 09:11:59 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11076327 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0224B14E5 for ; Mon, 5 Aug 2019 09:12:37 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E3568286A4 for ; Mon, 5 Aug 2019 09:12:36 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D6F492882C; Mon, 5 Aug 2019 09:12:36 +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=-7.7 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 634B4286A4 for ; Mon, 5 Aug 2019 09:12:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728182AbfHEJM3 (ORCPT ); Mon, 5 Aug 2019 05:12:29 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:35352 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728118AbfHEJM2 (ORCPT ); Mon, 5 Aug 2019 05:12:28 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From :Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=zRn6JVJn4nNeK9wOHHuTKPsPuOuS2mnSYsSa9Gwz7Rk=; b=RG4oxykeFe0JQMLxGAJ/8S5At7 GAA+923n7YeCeXJyTRg/ZL9Qyb+qPDEIyukrr+DcbOQq72koKv2qN+5j1CU6aIokVzQ4sVzvBcaiJ ++jVLfUSymTseLXFVf6usBQU9aUsW7R0FxhIbLRtCrsmVz8LQgwJ2h4VX31/Ozvyyx21f60h2MbfJ CWwUfwJuwZHzEiXGtZ7U22+YZJWxrZr02eb2yC5TmivTYjwDHaczSqQXwDnYMVNCh9482Q9MSjCK8 Uqnfuucwd7+du9IIxt0oItEHV40lhkfFXb38uyDMXjoCcwQxHlFnUp8mqXfI+3ot63ZjpR2ENbrpS Qlh3exXQ==; Received: from [195.167.85.94] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1huZ2V-00058g-L3; Mon, 05 Aug 2019 09:12:24 +0000 From: Christoph Hellwig To: iommu@lists.linux-foundation.org, Marek Szyprowski Cc: Takashi Iwai , Robin Murphy , Michal Simek , linux-arm-kernel@lists.infradead.org, linux-m68k@lists.linux-m68k.org, linux-parisc@vger.kernel.org, linux-sh@vger.kernel.org, linux-xtensa@linux-xtensa.org, linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 7/7] dma-mapping: provide a better default ->get_required_mask Date: Mon, 5 Aug 2019 12:11:59 +0300 Message-Id: <20190805091159.7826-8-hch@lst.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190805091159.7826-1-hch@lst.de> References: <20190805091159.7826-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-parisc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Most dma_map_ops instances are IOMMUs that work perfectly fine in 32-bits of IOVA space, and the generic direct mapping code already provides its own routines that is intelligent based on the amount of memory actually present. Wire up the dma-direct routine for the ARM direct mapping code as well, and otherwise default to the constant 32-bit mask. This way we only need to override it for the occasional odd IOMMU that requires 64-bit IOVA support, or IOMMU drivers that are more efficient if they can fall back to the direct mapping. Signed-off-by: Christoph Hellwig --- arch/arm/mm/dma-mapping.c | 3 +++ arch/powerpc/platforms/ps3/system-bus.c | 7 ------ arch/x86/kernel/amd_gart_64.c | 1 + kernel/dma/mapping.c | 30 +++++++++---------------- 4 files changed, 14 insertions(+), 27 deletions(-) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 4410af33c5c4..9c9a23e5600d 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -192,6 +193,7 @@ const struct dma_map_ops arm_dma_ops = { .sync_sg_for_cpu = arm_dma_sync_sg_for_cpu, .sync_sg_for_device = arm_dma_sync_sg_for_device, .dma_supported = arm_dma_supported, + .get_required_mask = dma_direct_get_required_mask, }; EXPORT_SYMBOL(arm_dma_ops); @@ -212,6 +214,7 @@ const struct dma_map_ops arm_coherent_dma_ops = { .map_sg = arm_dma_map_sg, .map_resource = dma_direct_map_resource, .dma_supported = arm_dma_supported, + .get_required_mask = dma_direct_get_required_mask, }; EXPORT_SYMBOL(arm_coherent_dma_ops); diff --git a/arch/powerpc/platforms/ps3/system-bus.c b/arch/powerpc/platforms/ps3/system-bus.c index 70fcc9736a8c..3542b7bd6a46 100644 --- a/arch/powerpc/platforms/ps3/system-bus.c +++ b/arch/powerpc/platforms/ps3/system-bus.c @@ -686,18 +686,12 @@ static int ps3_dma_supported(struct device *_dev, u64 mask) return mask >= DMA_BIT_MASK(32); } -static u64 ps3_dma_get_required_mask(struct device *_dev) -{ - return DMA_BIT_MASK(32); -} - static const struct dma_map_ops ps3_sb_dma_ops = { .alloc = ps3_alloc_coherent, .free = ps3_free_coherent, .map_sg = ps3_sb_map_sg, .unmap_sg = ps3_sb_unmap_sg, .dma_supported = ps3_dma_supported, - .get_required_mask = ps3_dma_get_required_mask, .map_page = ps3_sb_map_page, .unmap_page = ps3_unmap_page, .mmap = dma_common_mmap, @@ -710,7 +704,6 @@ static const struct dma_map_ops ps3_ioc0_dma_ops = { .map_sg = ps3_ioc0_map_sg, .unmap_sg = ps3_ioc0_unmap_sg, .dma_supported = ps3_dma_supported, - .get_required_mask = ps3_dma_get_required_mask, .map_page = ps3_ioc0_map_page, .unmap_page = ps3_unmap_page, .mmap = dma_common_mmap, diff --git a/arch/x86/kernel/amd_gart_64.c b/arch/x86/kernel/amd_gart_64.c index a65b4a9c7f87..d02662238b57 100644 --- a/arch/x86/kernel/amd_gart_64.c +++ b/arch/x86/kernel/amd_gart_64.c @@ -680,6 +680,7 @@ static const struct dma_map_ops gart_dma_ops = { .dma_supported = dma_direct_supported, .mmap = dma_common_mmap, .get_sgtable = dma_common_get_sgtable, + .get_required_mask = dma_direct_get_required_mask, }; static void gart_iommu_shutdown(void) diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index 47765c96fe09..96599f39f67a 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -247,25 +247,6 @@ int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma, } EXPORT_SYMBOL(dma_mmap_attrs); -static u64 dma_default_get_required_mask(struct device *dev) -{ - u32 low_totalram = ((max_pfn - 1) << PAGE_SHIFT); - u32 high_totalram = ((max_pfn - 1) >> (32 - PAGE_SHIFT)); - u64 mask; - - if (!high_totalram) { - /* convert to mask just covering totalram */ - low_totalram = (1 << (fls(low_totalram) - 1)); - low_totalram += low_totalram - 1; - mask = low_totalram; - } else { - high_totalram = (1 << (fls(high_totalram) - 1)); - high_totalram += high_totalram - 1; - mask = (((u64)high_totalram) << 32) + 0xffffffff; - } - return mask; -} - u64 dma_get_required_mask(struct device *dev) { const struct dma_map_ops *ops = get_dma_ops(dev); @@ -274,7 +255,16 @@ u64 dma_get_required_mask(struct device *dev) return dma_direct_get_required_mask(dev); if (ops->get_required_mask) return ops->get_required_mask(dev); - return dma_default_get_required_mask(dev); + + /* + * We require every DMA ops implementation to at least support a 32-bit + * DMA mask (and use bounce buffering if that isn't supported in + * hardware). As the direct mapping code has its own routine to + * actually report an optimal mask we default to 32-bit here as that + * is the right thing for most IOMMUs, and at least not actively + * harmful in general. + */ + return DMA_BIT_MASK(32); } EXPORT_SYMBOL_GPL(dma_get_required_mask);