From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,UNPARSEABLE_RELAY, URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 610CBC43387 for ; Tue, 18 Dec 2018 20:36:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1AB8B20675 for ; Tue, 18 Dec 2018 20:36:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727814AbeLRUgW (ORCPT ); Tue, 18 Dec 2018 15:36:22 -0500 Received: from bhuna.collabora.co.uk ([46.235.227.227]:49954 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726718AbeLRUeq (ORCPT ); Tue, 18 Dec 2018 15:34:46 -0500 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: gtucker) with ESMTPSA id C366A2639CE Subject: Re: [15/15] dma-mapping: bypass indirect calls for dma-direct To: Christoph Hellwig Cc: iommu@lists.linux-foundation.org, Linus Torvalds , Jesper Dangaard Brouer , Tariq Toukan , Ilias Apalodimas , =?UTF-8?Q?Toke_H=c3=b8iland-J=c3=b8rgensen?= , Robin Murphy , Konrad Rzeszutek Wilk , Tony Luck , Fenghua Yu , Marek Szyprowski , Keith Busch , Jonathan Derrick , linux-pci@vger.kernel.org, linux-ia64@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, ezequiel Garcia , "linux-arm-kernel@lists.infradead.org" References: <20181207190720.18517-16-hch@lst.de> From: Guillaume Tucker Message-ID: <2e779fa7-dc9f-7ed8-252a-5d20c5deca9c@collabora.com> Date: Tue, 18 Dec 2018 20:34:37 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.3.0 MIME-Version: 1.0 In-Reply-To: <20181207190720.18517-16-hch@lst.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/12/2018 19:07, Christoph Hellwig wrote: > Avoid expensive indirect calls in the fast path DMA mapping > operations by directly calling the dma_direct_* ops if we are using > the directly mapped DMA operations. > > Signed-off-by: Christoph Hellwig > Signed-off-by: Christoph Hellwig > Reported-by: Marek Szyprowski > Tested-by: Marek Szyprowski I've run a semi-automated bisection on kernelci.org and found that this patch appeared to cause some regressions in linux-next on the rk3399-gru-kevin arm64 platform. The bisection was run between next-20181128 and its merge base in mainline master (6531e115b7ab) with a plain defconfig. The problems seem to start with this message: [ 3.242163] mmc1: Unable to allocate ADMA buffers - falling back to standard DMA then we can see this kind of warnings: [ 3.424261] mmc1: asked for transfer of 512 bytes exceeds bounce buffer 0 bytes [ 3.432488] WARNING: CPU: 3 PID: 1596 at ../drivers/mmc/host/sdhci.c:1050 sdhci_send_command+0x8f0/0xfe8 see also: [ 16.046084] rk_iommu ff8f3f00.iommu: DMA map error for DT The full kernel log is available here: https://lava.collabora.co.uk/scheduler/job/1395093 Reverting this patch makes the errors go away, but I haven't done any further investigation so the actual problem may well lie somewhere else. Hope this helps! Best wishes, Guillaume > --- > arch/alpha/include/asm/dma-mapping.h | 2 +- > arch/arc/mm/cache.c | 2 +- > arch/arm/include/asm/dma-mapping.h | 2 +- > arch/arm/mm/dma-mapping-nommu.c | 14 +--- > arch/arm64/mm/dma-mapping.c | 3 - > arch/ia64/hp/common/hwsw_iommu.c | 2 +- > arch/ia64/hp/common/sba_iommu.c | 4 +- > arch/ia64/kernel/dma-mapping.c | 1 - > arch/mips/include/asm/dma-mapping.h | 2 +- > arch/parisc/kernel/setup.c | 4 - > arch/sparc/include/asm/dma-mapping.h | 4 +- > arch/x86/kernel/pci-dma.c | 2 +- > drivers/gpu/drm/vmwgfx/vmwgfx_drv.c | 2 +- > drivers/iommu/amd_iommu.c | 13 +--- > include/asm-generic/dma-mapping.h | 2 +- > include/linux/dma-direct.h | 17 ---- > include/linux/dma-mapping.h | 111 +++++++++++++++++++++++---- > include/linux/dma-noncoherent.h | 5 +- > kernel/dma/direct.c | 37 ++------- > kernel/dma/mapping.c | 40 ++++++---- > 20 files changed, 150 insertions(+), 119 deletions(-) > > diff --git a/arch/alpha/include/asm/dma-mapping.h b/arch/alpha/include/asm/dma-mapping.h > index 8beeafd4f68e..0ee6a5c99b16 100644 > --- a/arch/alpha/include/asm/dma-mapping.h > +++ b/arch/alpha/include/asm/dma-mapping.h > @@ -7,7 +7,7 @@ extern const struct dma_map_ops alpha_pci_ops; > static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus) > { > #ifdef CONFIG_ALPHA_JENSEN > - return &dma_direct_ops; > + return NULL; > #else > return &alpha_pci_ops; > #endif > diff --git a/arch/arc/mm/cache.c b/arch/arc/mm/cache.c > index f2701c13a66b..e188bb3ede53 100644 > --- a/arch/arc/mm/cache.c > +++ b/arch/arc/mm/cache.c > @@ -1280,7 +1280,7 @@ void __init arc_cache_init_master(void) > /* > * In case of IOC (say IOC+SLC case), pointers above could still be set > * but end up not being relevant as the first function in chain is not > - * called at all for @dma_direct_ops > + * called at all for devices using coherent DMA. > * arch_sync_dma_for_cpu() -> dma_cache_*() -> __dma_cache_*() > */ > } > diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h > index 965b7c846ecb..31d3b96f0f4b 100644 > --- a/arch/arm/include/asm/dma-mapping.h > +++ b/arch/arm/include/asm/dma-mapping.h > @@ -18,7 +18,7 @@ extern const struct dma_map_ops arm_coherent_dma_ops; > > static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus) > { > - return IS_ENABLED(CONFIG_MMU) ? &arm_dma_ops : &dma_direct_ops; > + return IS_ENABLED(CONFIG_MMU) ? &arm_dma_ops : NULL; > } > > #ifdef __arch_page_to_dma > diff --git a/arch/arm/mm/dma-mapping-nommu.c b/arch/arm/mm/dma-mapping-nommu.c > index 712416ecd8e6..f304b10e23a4 100644 > --- a/arch/arm/mm/dma-mapping-nommu.c > +++ b/arch/arm/mm/dma-mapping-nommu.c > @@ -22,7 +22,7 @@ > #include "dma.h" > > /* > - * dma_direct_ops is used if > + * The generic direct mapping code is used if > * - MMU/MPU is off > * - cpu is v7m w/o cache support > * - device is coherent > @@ -209,16 +209,9 @@ const struct dma_map_ops arm_nommu_dma_ops = { > }; > EXPORT_SYMBOL(arm_nommu_dma_ops); > > -static const struct dma_map_ops *arm_nommu_get_dma_map_ops(bool coherent) > -{ > - return coherent ? &dma_direct_ops : &arm_nommu_dma_ops; > -} > - > void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, > const struct iommu_ops *iommu, bool coherent) > { > - const struct dma_map_ops *dma_ops; > - > if (IS_ENABLED(CONFIG_CPU_V7M)) { > /* > * Cache support for v7m is optional, so can be treated as > @@ -234,7 +227,6 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, > dev->archdata.dma_coherent = (get_cr() & CR_M) ? coherent : true; > } > > - dma_ops = arm_nommu_get_dma_map_ops(dev->archdata.dma_coherent); > - > - set_dma_ops(dev, dma_ops); > + if (!dev->archdata.dma_coherent) > + set_dma_ops(dev, &arm_nommu_dma_ops); > } > diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c > index ab1e417204d0..95eda81e3f2d 100644 > --- a/arch/arm64/mm/dma-mapping.c > +++ b/arch/arm64/mm/dma-mapping.c > @@ -462,9 +462,6 @@ static void __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, > void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, > const struct iommu_ops *iommu, bool coherent) > { > - if (!dev->dma_ops) > - dev->dma_ops = &dma_direct_ops; > - > dev->dma_coherent = coherent; > __iommu_setup_dma_ops(dev, dma_base, size, iommu); > > diff --git a/arch/ia64/hp/common/hwsw_iommu.c b/arch/ia64/hp/common/hwsw_iommu.c > index f40ca499b246..8840ed97712f 100644 > --- a/arch/ia64/hp/common/hwsw_iommu.c > +++ b/arch/ia64/hp/common/hwsw_iommu.c > @@ -38,7 +38,7 @@ static inline int use_swiotlb(struct device *dev) > const struct dma_map_ops *hwsw_dma_get_ops(struct device *dev) > { > if (use_swiotlb(dev)) > - return &dma_direct_ops; > + return NULL; > return &sba_dma_ops; > } > EXPORT_SYMBOL(hwsw_dma_get_ops); > diff --git a/arch/ia64/hp/common/sba_iommu.c b/arch/ia64/hp/common/sba_iommu.c > index 5ee74820a0f6..5a361e51cb1e 100644 > --- a/arch/ia64/hp/common/sba_iommu.c > +++ b/arch/ia64/hp/common/sba_iommu.c > @@ -2078,7 +2078,7 @@ sba_init(void) > * a successful kdump kernel boot is to use the swiotlb. > */ > if (is_kdump_kernel()) { > - dma_ops = &dma_direct_ops; > + dma_ops = NULL; > if (swiotlb_late_init_with_default_size(64 * (1<<20)) != 0) > panic("Unable to initialize software I/O TLB:" > " Try machvec=dig boot option"); > @@ -2100,7 +2100,7 @@ sba_init(void) > * If we didn't find something sba_iommu can claim, we > * need to setup the swiotlb and switch to the dig machvec. > */ > - dma_ops = &dma_direct_ops; > + dma_ops = NULL; > if (swiotlb_late_init_with_default_size(64 * (1<<20)) != 0) > panic("Unable to find SBA IOMMU or initialize " > "software I/O TLB: Try machvec=dig boot option"); > diff --git a/arch/ia64/kernel/dma-mapping.c b/arch/ia64/kernel/dma-mapping.c > index 80cd3e1ea95a..ad7d9963de34 100644 > --- a/arch/ia64/kernel/dma-mapping.c > +++ b/arch/ia64/kernel/dma-mapping.c > @@ -36,7 +36,6 @@ long arch_dma_coherent_to_pfn(struct device *dev, void *cpu_addr, > > void __init swiotlb_dma_init(void) > { > - dma_ops = &dma_direct_ops; > swiotlb_init(1); > } > #endif > diff --git a/arch/mips/include/asm/dma-mapping.h b/arch/mips/include/asm/dma-mapping.h > index 69f914667f3e..20dfaad3a55d 100644 > --- a/arch/mips/include/asm/dma-mapping.h > +++ b/arch/mips/include/asm/dma-mapping.h > @@ -11,7 +11,7 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus) > #if defined(CONFIG_MACH_JAZZ) > return &jazz_dma_ops; > #else > - return &dma_direct_ops; > + return NULL; > #endif > } > > diff --git a/arch/parisc/kernel/setup.c b/arch/parisc/kernel/setup.c > index cd227f1cf629..54818cd78bd0 100644 > --- a/arch/parisc/kernel/setup.c > +++ b/arch/parisc/kernel/setup.c > @@ -99,10 +99,6 @@ void __init dma_ops_init(void) > > case pcxl2: > pa7300lc_init(); > - case pcxl: /* falls through */ > - case pcxs: > - case pcxt: > - hppa_dma_ops = &dma_direct_ops; > break; > default: > break; > diff --git a/arch/sparc/include/asm/dma-mapping.h b/arch/sparc/include/asm/dma-mapping.h > index b0bb2fcaf1c9..59f5a0f17316 100644 > --- a/arch/sparc/include/asm/dma-mapping.h > +++ b/arch/sparc/include/asm/dma-mapping.h > @@ -14,11 +14,11 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus) > { > #ifdef CONFIG_SPARC_LEON > if (sparc_cpu_model == sparc_leon) > - return &dma_direct_ops; > + return NULL; > #endif > #if defined(CONFIG_SPARC32) && defined(CONFIG_PCI) > if (bus == &pci_bus_type) > - return &dma_direct_ops; > + return NULL; > #endif > return dma_ops; > } > diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c > index f4562fcec681..d460998ae828 100644 > --- a/arch/x86/kernel/pci-dma.c > +++ b/arch/x86/kernel/pci-dma.c > @@ -17,7 +17,7 @@ > > static bool disable_dac_quirk __read_mostly; > > -const struct dma_map_ops *dma_ops = &dma_direct_ops; > +const struct dma_map_ops *dma_ops; > EXPORT_SYMBOL(dma_ops); > > #ifdef CONFIG_IOMMU_DEBUG > diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c > index 61a84b958d67..50637f372e9f 100644 > --- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c > +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c > @@ -581,7 +581,7 @@ static int vmw_dma_select_mode(struct vmw_private *dev_priv) > > dev_priv->map_mode = vmw_dma_map_populate; > > - if (dma_ops->sync_single_for_cpu) > + if (dma_ops && dma_ops->sync_single_for_cpu) > dev_priv->map_mode = vmw_dma_alloc_coherent; > #ifdef CONFIG_SWIOTLB > if (swiotlb_nr_tbl() == 0) > diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c > index c5d6c7c42b0a..567221cca13c 100644 > --- a/drivers/iommu/amd_iommu.c > +++ b/drivers/iommu/amd_iommu.c > @@ -2184,7 +2184,7 @@ static int amd_iommu_add_device(struct device *dev) > dev_name(dev)); > > iommu_ignore_device(dev); > - dev->dma_ops = &dma_direct_ops; > + dev->dma_ops = NULL; > goto out; > } > init_iommu_group(dev); > @@ -2770,17 +2770,6 @@ int __init amd_iommu_init_dma_ops(void) > swiotlb = (iommu_pass_through || sme_me_mask) ? 1 : 0; > iommu_detected = 1; > > - /* > - * In case we don't initialize SWIOTLB (actually the common case > - * when AMD IOMMU is enabled and SME is not active), make sure there > - * are global dma_ops set as a fall-back for devices not handled by > - * this driver (for example non-PCI devices). When SME is active, > - * make sure that swiotlb variable remains set so the global dma_ops > - * continue to be SWIOTLB. > - */ > - if (!swiotlb) > - dma_ops = &dma_direct_ops; > - > if (amd_iommu_unmap_flush) > pr_info("AMD-Vi: IO/TLB flush on unmap enabled\n"); > else > diff --git a/include/asm-generic/dma-mapping.h b/include/asm-generic/dma-mapping.h > index 880a292d792f..c13f46109e88 100644 > --- a/include/asm-generic/dma-mapping.h > +++ b/include/asm-generic/dma-mapping.h > @@ -4,7 +4,7 @@ > > static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus) > { > - return &dma_direct_ops; > + return NULL; > } > > #endif /* _ASM_GENERIC_DMA_MAPPING_H */ > diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h > index 3b0a3ea3876d..b7338702592a 100644 > --- a/include/linux/dma-direct.h > +++ b/include/linux/dma-direct.h > @@ -60,22 +60,5 @@ void dma_direct_free_pages(struct device *dev, size_t size, void *cpu_addr, > struct page *__dma_direct_alloc_pages(struct device *dev, size_t size, > dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs); > void __dma_direct_free_pages(struct device *dev, size_t size, struct page *page); > -dma_addr_t dma_direct_map_page(struct device *dev, struct page *page, > - unsigned long offset, size_t size, enum dma_data_direction dir, > - unsigned long attrs); > -void dma_direct_unmap_page(struct device *dev, dma_addr_t addr, > - size_t size, enum dma_data_direction dir, unsigned long attrs); > -int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents, > - enum dma_data_direction dir, unsigned long attrs); > -void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl, > - int nents, enum dma_data_direction dir, unsigned long attrs); > -void dma_direct_sync_single_for_device(struct device *dev, > - dma_addr_t addr, size_t size, enum dma_data_direction dir); > -void dma_direct_sync_sg_for_device(struct device *dev, > - struct scatterlist *sgl, int nents, enum dma_data_direction dir); > -void dma_direct_sync_single_for_cpu(struct device *dev, > - dma_addr_t addr, size_t size, enum dma_data_direction dir); > -void dma_direct_sync_sg_for_cpu(struct device *dev, > - struct scatterlist *sgl, int nents, enum dma_data_direction dir); > int dma_direct_supported(struct device *dev, u64 mask); > #endif /* _LINUX_DMA_DIRECT_H */ > diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h > index 269ee27fc3d9..f422aec0f53c 100644 > --- a/include/linux/dma-mapping.h > +++ b/include/linux/dma-mapping.h > @@ -134,7 +134,6 @@ struct dma_map_ops { > > #define DMA_MAPPING_ERROR (~(dma_addr_t)0) > > -extern const struct dma_map_ops dma_direct_ops; > extern const struct dma_map_ops dma_virt_ops; > extern const struct dma_map_ops dma_dummy_ops; > > @@ -222,6 +221,69 @@ static inline const struct dma_map_ops *get_dma_ops(struct device *dev) > } > #endif > > +static inline bool dma_is_direct(const struct dma_map_ops *ops) > +{ > + return likely(!ops); > +} > + > +/* > + * All the dma_direct_* declarations are here just for the indirect call bypass, > + * and must not be used directly drivers! > + */ > +dma_addr_t dma_direct_map_page(struct device *dev, struct page *page, > + unsigned long offset, size_t size, enum dma_data_direction dir, > + unsigned long attrs); > +int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents, > + enum dma_data_direction dir, unsigned long attrs); > + > +#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \ > + defined(CONFIG_SWIOTLB) > +void dma_direct_sync_single_for_device(struct device *dev, > + dma_addr_t addr, size_t size, enum dma_data_direction dir); > +void dma_direct_sync_sg_for_device(struct device *dev, > + struct scatterlist *sgl, int nents, enum dma_data_direction dir); > +#else > +static inline void dma_direct_sync_single_for_device(struct device *dev, > + dma_addr_t addr, size_t size, enum dma_data_direction dir) > +{ > +} > +static inline void dma_direct_sync_sg_for_device(struct device *dev, > + struct scatterlist *sgl, int nents, enum dma_data_direction dir) > +{ > +} > +#endif > + > +#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \ > + defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) || \ > + defined(CONFIG_SWIOTLB) > +void dma_direct_unmap_page(struct device *dev, dma_addr_t addr, > + size_t size, enum dma_data_direction dir, unsigned long attrs); > +void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl, > + int nents, enum dma_data_direction dir, unsigned long attrs); > +void dma_direct_sync_single_for_cpu(struct device *dev, > + dma_addr_t addr, size_t size, enum dma_data_direction dir); > +void dma_direct_sync_sg_for_cpu(struct device *dev, > + struct scatterlist *sgl, int nents, enum dma_data_direction dir); > +#else > +static inline void dma_direct_unmap_page(struct device *dev, dma_addr_t addr, > + size_t size, enum dma_data_direction dir, unsigned long attrs) > +{ > +} > +static inline void dma_direct_unmap_sg(struct device *dev, > + struct scatterlist *sgl, int nents, enum dma_data_direction dir, > + unsigned long attrs) > +{ > +} > +static inline void dma_direct_sync_single_for_cpu(struct device *dev, > + dma_addr_t addr, size_t size, enum dma_data_direction dir) > +{ > +} > +static inline void dma_direct_sync_sg_for_cpu(struct device *dev, > + struct scatterlist *sgl, int nents, enum dma_data_direction dir) > +{ > +} > +#endif > + > static inline dma_addr_t dma_map_single_attrs(struct device *dev, void *ptr, > size_t size, > enum dma_data_direction dir, > @@ -232,9 +294,12 @@ static inline dma_addr_t dma_map_single_attrs(struct device *dev, void *ptr, > > BUG_ON(!valid_dma_direction(dir)); > debug_dma_map_single(dev, ptr, size); > - addr = ops->map_page(dev, virt_to_page(ptr), > - offset_in_page(ptr), size, > - dir, attrs); > + if (dma_is_direct(ops)) > + addr = dma_direct_map_page(dev, virt_to_page(ptr), > + offset_in_page(ptr), size, dir, attrs); > + else > + addr = ops->map_page(dev, virt_to_page(ptr), > + offset_in_page(ptr), size, dir, attrs); > debug_dma_map_page(dev, virt_to_page(ptr), > offset_in_page(ptr), size, > dir, addr, true); > @@ -249,7 +314,9 @@ static inline void dma_unmap_single_attrs(struct device *dev, dma_addr_t addr, > const struct dma_map_ops *ops = get_dma_ops(dev); > > BUG_ON(!valid_dma_direction(dir)); > - if (ops->unmap_page) > + if (dma_is_direct(ops)) > + dma_direct_unmap_page(dev, addr, size, dir, attrs); > + else if (ops->unmap_page) > ops->unmap_page(dev, addr, size, dir, attrs); > debug_dma_unmap_page(dev, addr, size, dir, true); > } > @@ -272,7 +339,10 @@ static inline int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, > int ents; > > BUG_ON(!valid_dma_direction(dir)); > - ents = ops->map_sg(dev, sg, nents, dir, attrs); > + if (dma_is_direct(ops)) > + ents = dma_direct_map_sg(dev, sg, nents, dir, attrs); > + else > + ents = ops->map_sg(dev, sg, nents, dir, attrs); > BUG_ON(ents < 0); > debug_dma_map_sg(dev, sg, nents, ents, dir); > > @@ -287,7 +357,9 @@ static inline void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg > > BUG_ON(!valid_dma_direction(dir)); > debug_dma_unmap_sg(dev, sg, nents, dir); > - if (ops->unmap_sg) > + if (dma_is_direct(ops)) > + dma_direct_unmap_sg(dev, sg, nents, dir, attrs); > + else if (ops->unmap_sg) > ops->unmap_sg(dev, sg, nents, dir, attrs); > } > > @@ -301,7 +373,10 @@ static inline dma_addr_t dma_map_page_attrs(struct device *dev, > dma_addr_t addr; > > BUG_ON(!valid_dma_direction(dir)); > - addr = ops->map_page(dev, page, offset, size, dir, attrs); > + if (dma_is_direct(ops)) > + addr = dma_direct_map_page(dev, page, offset, size, dir, attrs); > + else > + addr = ops->map_page(dev, page, offset, size, dir, attrs); > debug_dma_map_page(dev, page, offset, size, dir, addr, false); > > return addr; > @@ -322,7 +397,7 @@ static inline dma_addr_t dma_map_resource(struct device *dev, > BUG_ON(pfn_valid(PHYS_PFN(phys_addr))); > > addr = phys_addr; > - if (ops->map_resource) > + if (ops && ops->map_resource) > addr = ops->map_resource(dev, phys_addr, size, dir, attrs); > > debug_dma_map_resource(dev, phys_addr, size, dir, addr); > @@ -337,7 +412,7 @@ static inline void dma_unmap_resource(struct device *dev, dma_addr_t addr, > const struct dma_map_ops *ops = get_dma_ops(dev); > > BUG_ON(!valid_dma_direction(dir)); > - if (ops->unmap_resource) > + if (ops && ops->unmap_resource) > ops->unmap_resource(dev, addr, size, dir, attrs); > debug_dma_unmap_resource(dev, addr, size, dir); > } > @@ -349,7 +424,9 @@ static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, > const struct dma_map_ops *ops = get_dma_ops(dev); > > BUG_ON(!valid_dma_direction(dir)); > - if (ops->sync_single_for_cpu) > + if (dma_is_direct(ops)) > + dma_direct_sync_single_for_cpu(dev, addr, size, dir); > + else if (ops->sync_single_for_cpu) > ops->sync_single_for_cpu(dev, addr, size, dir); > debug_dma_sync_single_for_cpu(dev, addr, size, dir); > } > @@ -368,7 +445,9 @@ static inline void dma_sync_single_for_device(struct device *dev, > const struct dma_map_ops *ops = get_dma_ops(dev); > > BUG_ON(!valid_dma_direction(dir)); > - if (ops->sync_single_for_device) > + if (dma_is_direct(ops)) > + dma_direct_sync_single_for_device(dev, addr, size, dir); > + else if (ops->sync_single_for_device) > ops->sync_single_for_device(dev, addr, size, dir); > debug_dma_sync_single_for_device(dev, addr, size, dir); > } > @@ -387,7 +466,9 @@ dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, > const struct dma_map_ops *ops = get_dma_ops(dev); > > BUG_ON(!valid_dma_direction(dir)); > - if (ops->sync_sg_for_cpu) > + if (dma_is_direct(ops)) > + dma_direct_sync_sg_for_cpu(dev, sg, nelems, dir); > + else if (ops->sync_sg_for_cpu) > ops->sync_sg_for_cpu(dev, sg, nelems, dir); > debug_dma_sync_sg_for_cpu(dev, sg, nelems, dir); > } > @@ -399,7 +480,9 @@ dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, > const struct dma_map_ops *ops = get_dma_ops(dev); > > BUG_ON(!valid_dma_direction(dir)); > - if (ops->sync_sg_for_device) > + if (dma_is_direct(ops)) > + dma_direct_sync_sg_for_device(dev, sg, nelems, dir); > + else if (ops->sync_sg_for_device) > ops->sync_sg_for_device(dev, sg, nelems, dir); > debug_dma_sync_sg_for_device(dev, sg, nelems, dir); > > diff --git a/include/linux/dma-noncoherent.h b/include/linux/dma-noncoherent.h > index 306557331d7d..69b36ed31a99 100644 > --- a/include/linux/dma-noncoherent.h > +++ b/include/linux/dma-noncoherent.h > @@ -38,7 +38,10 @@ pgprot_t arch_dma_mmap_pgprot(struct device *dev, pgprot_t prot, > void arch_dma_cache_sync(struct device *dev, void *vaddr, size_t size, > enum dma_data_direction direction); > #else > -#define arch_dma_cache_sync NULL > +static inline void arch_dma_cache_sync(struct device *dev, void *vaddr, > + size_t size, enum dma_data_direction direction) > +{ > +} > #endif /* CONFIG_DMA_NONCOHERENT_CACHE_SYNC */ > > #ifdef CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE > diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c > index 85d8286a0ba2..79da61b49fa4 100644 > --- a/kernel/dma/direct.c > +++ b/kernel/dma/direct.c > @@ -223,6 +223,7 @@ void dma_direct_sync_single_for_device(struct device *dev, > if (!dev_is_dma_coherent(dev)) > arch_sync_dma_for_device(dev, paddr, size, dir); > } > +EXPORT_SYMBOL(dma_direct_sync_single_for_device); > > void dma_direct_sync_sg_for_device(struct device *dev, > struct scatterlist *sgl, int nents, enum dma_data_direction dir) > @@ -240,6 +241,7 @@ void dma_direct_sync_sg_for_device(struct device *dev, > dir); > } > } > +EXPORT_SYMBOL(dma_direct_sync_sg_for_device); > #endif > > #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \ > @@ -258,6 +260,7 @@ void dma_direct_sync_single_for_cpu(struct device *dev, > if (unlikely(is_swiotlb_buffer(paddr))) > swiotlb_tbl_sync_single(dev, paddr, size, dir, SYNC_FOR_CPU); > } > +EXPORT_SYMBOL(dma_direct_sync_single_for_cpu); > > void dma_direct_sync_sg_for_cpu(struct device *dev, > struct scatterlist *sgl, int nents, enum dma_data_direction dir) > @@ -277,6 +280,7 @@ void dma_direct_sync_sg_for_cpu(struct device *dev, > if (!dev_is_dma_coherent(dev)) > arch_sync_dma_for_cpu_all(dev); > } > +EXPORT_SYMBOL(dma_direct_sync_sg_for_cpu); > > void dma_direct_unmap_page(struct device *dev, dma_addr_t addr, > size_t size, enum dma_data_direction dir, unsigned long attrs) > @@ -289,6 +293,7 @@ void dma_direct_unmap_page(struct device *dev, dma_addr_t addr, > if (unlikely(is_swiotlb_buffer(phys))) > swiotlb_tbl_unmap_single(dev, phys, size, dir, attrs); > } > +EXPORT_SYMBOL(dma_direct_unmap_page); > > void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl, > int nents, enum dma_data_direction dir, unsigned long attrs) > @@ -300,11 +305,7 @@ void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl, > dma_direct_unmap_page(dev, sg->dma_address, sg_dma_len(sg), dir, > attrs); > } > -#else > -void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl, > - int nents, enum dma_data_direction dir, unsigned long attrs) > -{ > -} > +EXPORT_SYMBOL(dma_direct_unmap_sg); > #endif > > static inline bool dma_direct_possible(struct device *dev, dma_addr_t dma_addr, > @@ -331,6 +332,7 @@ dma_addr_t dma_direct_map_page(struct device *dev, struct page *page, > arch_sync_dma_for_device(dev, phys, size, dir); > return dma_addr; > } > +EXPORT_SYMBOL(dma_direct_map_page); > > int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents, > enum dma_data_direction dir, unsigned long attrs) > @@ -352,6 +354,7 @@ int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents, > dma_direct_unmap_sg(dev, sgl, i, dir, attrs | DMA_ATTR_SKIP_CPU_SYNC); > return 0; > } > +EXPORT_SYMBOL(dma_direct_map_sg); > > /* > * Because 32-bit DMA masks are so common we expect every architecture to be > @@ -372,27 +375,3 @@ int dma_direct_supported(struct device *dev, u64 mask) > > return mask >= phys_to_dma(dev, min_mask); > } > - > -const struct dma_map_ops dma_direct_ops = { > - .alloc = dma_direct_alloc, > - .free = dma_direct_free, > - .map_page = dma_direct_map_page, > - .map_sg = dma_direct_map_sg, > -#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \ > - defined(CONFIG_SWIOTLB) > - .sync_single_for_device = dma_direct_sync_single_for_device, > - .sync_sg_for_device = dma_direct_sync_sg_for_device, > -#endif > -#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \ > - defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) || \ > - defined(CONFIG_SWIOTLB) > - .sync_single_for_cpu = dma_direct_sync_single_for_cpu, > - .sync_sg_for_cpu = dma_direct_sync_sg_for_cpu, > - .unmap_page = dma_direct_unmap_page, > - .unmap_sg = dma_direct_unmap_sg, > -#endif > - .get_required_mask = dma_direct_get_required_mask, > - .dma_supported = dma_direct_supported, > - .cache_sync = arch_dma_cache_sync, > -}; > -EXPORT_SYMBOL(dma_direct_ops); > diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c > index 0b18cfbdde95..fc84c81029d9 100644 > --- a/kernel/dma/mapping.c > +++ b/kernel/dma/mapping.c > @@ -7,6 +7,7 @@ > */ > #include /* for max_pfn */ > #include > +#include > #include > #include > #include > @@ -229,8 +230,8 @@ int dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt, > unsigned long attrs) > { > const struct dma_map_ops *ops = get_dma_ops(dev); > - BUG_ON(!ops); > - if (ops->get_sgtable) > + > + if (!dma_is_direct(ops) && ops->get_sgtable) > return ops->get_sgtable(dev, sgt, cpu_addr, dma_addr, size, > attrs); > return dma_common_get_sgtable(dev, sgt, cpu_addr, dma_addr, size, > @@ -293,8 +294,8 @@ int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma, > unsigned long attrs) > { > const struct dma_map_ops *ops = get_dma_ops(dev); > - BUG_ON(!ops); > - if (ops->mmap) > + > + if (!dma_is_direct(ops) && ops->mmap) > return ops->mmap(dev, vma, cpu_addr, dma_addr, size, attrs); > return dma_common_mmap(dev, vma, cpu_addr, dma_addr, size, attrs); > } > @@ -324,6 +325,8 @@ u64 dma_get_required_mask(struct device *dev) > { > const struct dma_map_ops *ops = get_dma_ops(dev); > > + if (dma_is_direct(ops)) > + 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); > @@ -341,7 +344,6 @@ void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle, > const struct dma_map_ops *ops = get_dma_ops(dev); > void *cpu_addr; > > - BUG_ON(!ops); > WARN_ON_ONCE(dev && !dev->coherent_dma_mask); > > if (dma_alloc_from_dev_coherent(dev, size, dma_handle, &cpu_addr)) > @@ -352,10 +354,14 @@ void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle, > > if (!arch_dma_alloc_attrs(&dev)) > return NULL; > - if (!ops->alloc) > + > + if (dma_is_direct(ops)) > + cpu_addr = dma_direct_alloc(dev, size, dma_handle, flag, attrs); > + else if (ops->alloc) > + cpu_addr = ops->alloc(dev, size, dma_handle, flag, attrs); > + else > return NULL; > > - cpu_addr = ops->alloc(dev, size, dma_handle, flag, attrs); > debug_dma_alloc_coherent(dev, size, *dma_handle, cpu_addr); > return cpu_addr; > } > @@ -366,8 +372,6 @@ void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr, > { > const struct dma_map_ops *ops = get_dma_ops(dev); > > - BUG_ON(!ops); > - > if (dma_release_from_dev_coherent(dev, get_order(size), cpu_addr)) > return; > /* > @@ -379,11 +383,14 @@ void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr, > */ > WARN_ON(irqs_disabled()); > > - if (!ops->free || !cpu_addr) > + if (!cpu_addr) > return; > > debug_dma_free_coherent(dev, size, cpu_addr, dma_handle); > - ops->free(dev, size, cpu_addr, dma_handle, attrs); > + if (dma_is_direct(ops)) > + dma_direct_free(dev, size, cpu_addr, dma_handle, attrs); > + else if (ops->free) > + ops->free(dev, size, cpu_addr, dma_handle, attrs); > } > EXPORT_SYMBOL(dma_free_attrs); > > @@ -397,9 +404,9 @@ int dma_supported(struct device *dev, u64 mask) > { > const struct dma_map_ops *ops = get_dma_ops(dev); > > - if (!ops) > - return 0; > - if (!ops->dma_supported) > + if (dma_is_direct(ops)) > + return dma_direct_supported(dev, mask); > + if (ops->dma_supported) > return 1; > return ops->dma_supported(dev, mask); > } > @@ -437,7 +444,10 @@ void dma_cache_sync(struct device *dev, void *vaddr, size_t size, > const struct dma_map_ops *ops = get_dma_ops(dev); > > BUG_ON(!valid_dma_direction(dir)); > - if (ops->cache_sync) > + > + if (dma_is_direct(ops)) > + arch_dma_cache_sync(dev, vaddr, size, dir); > + else if (ops->cache_sync) > ops->cache_sync(dev, vaddr, size, dir); > } > EXPORT_SYMBOL(dma_cache_sync); >