From patchwork Thu Aug 8 15:59:58 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11084463 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 3211B912 for ; Thu, 8 Aug 2019 16:00:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1E17C2878E for ; Thu, 8 Aug 2019 16:00:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 12416287A1; Thu, 8 Aug 2019 16:00:51 +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=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 99AC0287C9 for ; Thu, 8 Aug 2019 16:00:45 +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:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version: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=vMDfYkgabQRhkiAZxibfenar3+hbZGRrMgrCRLmtJoA=; b=kGDiUksn0Z5Sot FKTgY2Es/JobaSDRSRrBKriqhraFuQ1mkzxkQJ8NrqXN0lPnEPJfxV+/QSslU+pU92R1b+SBgw/Is cIWGJcphk7f4WNwziU5qzocEZRRpxyTvftwsQqjP4+i3p3/Un7jQO7EAEDsiH7EOQ41PEQJW+eoQJ M6wP2I6scXQga/qCBmqvpMKU0xzlksl/xJS7d/Q9tG59jooaKAqubmUNG4yy7+0Bs0dWrdmLtUNfw fPMpu8QvCnAecKpeXL2qPsgp5anjI3VX/21fTUlzdMZ2Jra5sE2ezwMT0aAcjawvkKdvN/aK8sjbQ 4DYP0sZJbXuas7eUGoCQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hvkqK-0006lI-DX; Thu, 08 Aug 2019 16:00:44 +0000 Received: from [195.167.85.94] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1hvkq4-0006XB-S9; Thu, 08 Aug 2019 16:00:30 +0000 From: Christoph Hellwig To: iommu@lists.linux-foundation.org, Marek Szyprowski Subject: [PATCH 1/8] dma-mapping: provide a better default ->get_required_mask Date: Thu, 8 Aug 2019 18:59:58 +0300 Message-Id: <20190808160005.10325-2-hch@lst.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190808160005.10325-1-hch@lst.de> References: <20190808160005.10325-1-hch@lst.de> MIME-Version: 1.0 X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-xtensa@linux-xtensa.org, Michal Simek , Vladimir Murzin , linux-parisc@vger.kernel.org, linux-sh@vger.kernel.org, Takashi Iwai , linuxppc-dev@lists.ozlabs.org, Helge Deller , x86@kernel.org, linux-kernel@vger.kernel.org, linux-m68k@lists.linux-m68k.org, Robin Murphy , 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-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 8c0b0baeb398..ad64d32fb39a 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 98410119c47b..6818317073b9 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, }; @@ -708,7 +702,6 @@ 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, }; diff --git a/arch/x86/kernel/amd_gart_64.c b/arch/x86/kernel/amd_gart_64.c index a585ea6f686a..03ed9675f954 100644 --- a/arch/x86/kernel/amd_gart_64.c +++ b/arch/x86/kernel/amd_gart_64.c @@ -678,6 +678,7 @@ static const struct dma_map_ops gart_dma_ops = { .alloc = gart_alloc_coherent, .free = gart_free_coherent, .dma_supported = dma_direct_supported, + .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 b0038ca3aa92..9c0f6a8eb5cb 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -233,25 +233,6 @@ 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); @@ -260,7 +241,16 @@ 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);