From 8a2f11878771da65b8ac135c73b47dae13afbd62 Mon Sep 17 00:00:00 2001 From: Suren Baghdasaryan Date: Thu, 21 Mar 2024 09:36:39 -0700 Subject: change alloc_pages name in dma_map_ops to avoid name conflicts MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit After redefining alloc_pages, all uses of that name are being replaced. Change the conflicting names to prevent preprocessor from replacing them when it's not intended. Link: https://lkml.kernel.org/r/20240321163705.3067592-18-surenb@google.com Signed-off-by: Suren Baghdasaryan Tested-by: Kees Cook Cc: Alexander Viro Cc: Alex Gaynor Cc: Alice Ryhl Cc: Andreas Hindborg Cc: Benno Lossin Cc: "Björn Roy Baron" Cc: Boqun Feng Cc: Christoph Lameter Cc: Dennis Zhou Cc: Gary Guo Cc: Kent Overstreet Cc: Miguel Ojeda Cc: Pasha Tatashin Cc: Peter Zijlstra Cc: Tejun Heo Cc: Vlastimil Babka Cc: Wedson Almeida Filho Signed-off-by: Andrew Morton --- kernel/dma/mapping.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/dma/mapping.c') diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index 58db8fd70471..5e2d51e1cdf6 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -570,9 +570,9 @@ static struct page *__dma_alloc_pages(struct device *dev, size_t size, size = PAGE_ALIGN(size); if (dma_alloc_direct(dev, ops)) return dma_direct_alloc_pages(dev, size, dma_handle, dir, gfp); - if (!ops->alloc_pages) + if (!ops->alloc_pages_op) return NULL; - return ops->alloc_pages(dev, size, dma_handle, dir, gfp); + return ops->alloc_pages_op(dev, size, dma_handle, dir, gfp); } struct page *dma_alloc_pages(struct device *dev, size_t size, -- cgit v1.2.3-59-g8ed1b From fe7514b149e0a8a6f3031d286e52d40163b0b11a Mon Sep 17 00:00:00 2001 From: Alexander Lobakin Date: Tue, 7 May 2024 13:20:20 +0200 Subject: dma: compile-out DMA sync op calls when not used Some platforms do have DMA, but DMA there is always direct and coherent. Currently, even on such platforms DMA sync operations are compiled and called. Add a new hidden Kconfig symbol, DMA_NEED_SYNC, and set it only when either sync operations are needed or there is DMA ops or swiotlb or DMA debug is enabled. Compile global dma_sync_*() and dma_need_sync() only when it's set, otherwise provide empty inline stubs. The change allows for future optimizations of DMA sync calls depending on runtime conditions. Signed-off-by: Alexander Lobakin Signed-off-by: Christoph Hellwig --- include/linux/dma-mapping.h | 62 ++++++++++++++++++++++++--------------------- kernel/dma/Kconfig | 5 ++++ kernel/dma/mapping.c | 22 ++++++++-------- 3 files changed, 50 insertions(+), 39 deletions(-) (limited to 'kernel/dma/mapping.c') diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 4a658de44ee9..a569b56b25e2 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -117,14 +117,6 @@ dma_addr_t dma_map_resource(struct device *dev, phys_addr_t phys_addr, size_t size, enum dma_data_direction dir, unsigned long attrs); void dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size, enum dma_data_direction dir, unsigned long attrs); -void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size, - enum dma_data_direction dir); -void dma_sync_single_for_device(struct device *dev, dma_addr_t addr, - size_t size, enum dma_data_direction dir); -void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, - int nelems, enum dma_data_direction dir); -void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, - int nelems, enum dma_data_direction dir); void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t flag, unsigned long attrs); void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr, @@ -147,7 +139,6 @@ u64 dma_get_required_mask(struct device *dev); bool dma_addressing_limited(struct device *dev); size_t dma_max_mapping_size(struct device *dev); size_t dma_opt_mapping_size(struct device *dev); -bool dma_need_sync(struct device *dev, dma_addr_t dma_addr); unsigned long dma_get_merge_boundary(struct device *dev); struct sg_table *dma_alloc_noncontiguous(struct device *dev, size_t size, enum dma_data_direction dir, gfp_t gfp, unsigned long attrs); @@ -195,22 +186,6 @@ static inline void dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size, enum dma_data_direction dir, unsigned long attrs) { } -static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, - size_t size, enum dma_data_direction dir) -{ -} -static inline void dma_sync_single_for_device(struct device *dev, - dma_addr_t addr, size_t size, enum dma_data_direction dir) -{ -} -static inline void dma_sync_sg_for_cpu(struct device *dev, - struct scatterlist *sg, int nelems, enum dma_data_direction dir) -{ -} -static inline void dma_sync_sg_for_device(struct device *dev, - struct scatterlist *sg, int nelems, enum dma_data_direction dir) -{ -} static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr) { return -ENOMEM; @@ -277,10 +252,6 @@ static inline size_t dma_opt_mapping_size(struct device *dev) { return 0; } -static inline bool dma_need_sync(struct device *dev, dma_addr_t dma_addr) -{ - return false; -} static inline unsigned long dma_get_merge_boundary(struct device *dev) { return 0; @@ -310,6 +281,39 @@ static inline int dma_mmap_noncontiguous(struct device *dev, } #endif /* CONFIG_HAS_DMA */ +#if defined(CONFIG_HAS_DMA) && defined(CONFIG_DMA_NEED_SYNC) +void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size, + enum dma_data_direction dir); +void dma_sync_single_for_device(struct device *dev, dma_addr_t addr, + size_t size, enum dma_data_direction dir); +void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, + int nelems, enum dma_data_direction dir); +void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, + int nelems, enum dma_data_direction dir); +bool dma_need_sync(struct device *dev, dma_addr_t dma_addr); +#else /* !CONFIG_HAS_DMA || !CONFIG_DMA_NEED_SYNC */ +static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, + size_t size, enum dma_data_direction dir) +{ +} +static inline void dma_sync_single_for_device(struct device *dev, + dma_addr_t addr, size_t size, enum dma_data_direction dir) +{ +} +static inline void dma_sync_sg_for_cpu(struct device *dev, + struct scatterlist *sg, int nelems, enum dma_data_direction dir) +{ +} +static inline void dma_sync_sg_for_device(struct device *dev, + struct scatterlist *sg, int nelems, enum dma_data_direction dir) +{ +} +static inline bool dma_need_sync(struct device *dev, dma_addr_t dma_addr) +{ + return false; +} +#endif /* !CONFIG_HAS_DMA || !CONFIG_DMA_NEED_SYNC */ + struct page *dma_alloc_pages(struct device *dev, size_t size, dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp); void dma_free_pages(struct device *dev, size_t size, struct page *page, diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig index d62f5957f36b..c06e56be0ca1 100644 --- a/kernel/dma/Kconfig +++ b/kernel/dma/Kconfig @@ -107,6 +107,11 @@ config DMA_BOUNCE_UNALIGNED_KMALLOC bool depends on SWIOTLB +config DMA_NEED_SYNC + def_bool ARCH_HAS_SYNC_DMA_FOR_DEVICE || ARCH_HAS_SYNC_DMA_FOR_CPU || \ + ARCH_HAS_SYNC_DMA_FOR_CPU_ALL || DMA_API_DEBUG || DMA_OPS || \ + SWIOTLB + config DMA_RESTRICTED_POOL bool "DMA Restricted Pool" depends on OF && OF_RESERVED_MEM && SWIOTLB diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index 58db8fd70471..c78b78e95a26 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -329,6 +329,7 @@ void dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size, } EXPORT_SYMBOL(dma_unmap_resource); +#ifdef CONFIG_DMA_NEED_SYNC void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size, enum dma_data_direction dir) { @@ -385,6 +386,17 @@ void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, } EXPORT_SYMBOL(dma_sync_sg_for_device); +bool dma_need_sync(struct device *dev, dma_addr_t dma_addr) +{ + const struct dma_map_ops *ops = get_dma_ops(dev); + + if (dma_map_direct(dev, ops)) + return dma_direct_need_sync(dev, dma_addr); + return ops->sync_single_for_cpu || ops->sync_single_for_device; +} +EXPORT_SYMBOL_GPL(dma_need_sync); +#endif /* CONFIG_DMA_NEED_SYNC */ + /* * The whole dma_get_sgtable() idea is fundamentally unsafe - it seems * that the intention is to allow exporting memory allocated via the @@ -841,16 +853,6 @@ size_t dma_opt_mapping_size(struct device *dev) } EXPORT_SYMBOL_GPL(dma_opt_mapping_size); -bool dma_need_sync(struct device *dev, dma_addr_t dma_addr) -{ - const struct dma_map_ops *ops = get_dma_ops(dev); - - if (dma_map_direct(dev, ops)) - return dma_direct_need_sync(dev, dma_addr); - return ops->sync_single_for_cpu || ops->sync_single_for_device; -} -EXPORT_SYMBOL_GPL(dma_need_sync); - unsigned long dma_get_merge_boundary(struct device *dev) { const struct dma_map_ops *ops = get_dma_ops(dev); -- cgit v1.2.3-59-g8ed1b From f406c8e4b770ca3b0df84a17349e13f2b6b07d10 Mon Sep 17 00:00:00 2001 From: Alexander Lobakin Date: Tue, 7 May 2024 13:20:21 +0200 Subject: dma: avoid redundant calls for sync operations Quite often, devices do not need dma_sync operations on x86_64 at least. Indeed, when dev_is_dma_coherent(dev) is true and dev_use_swiotlb(dev) is false, iommu_dma_sync_single_for_cpu() and friends do nothing. However, indirectly calling them when CONFIG_RETPOLINE=y consumes about 10% of cycles on a cpu receiving packets from softirq at ~100Gbit rate. Even if/when CONFIG_RETPOLINE is not set, there is a cost of about 3%. Add dev->need_dma_sync boolean and turn it off during the device initialization (dma_set_mask()) depending on the setup: dev_is_dma_coherent() for the direct DMA, !(sync_single_for_device || sync_single_for_cpu) or the new dma_map_ops flag, %DMA_F_CAN_SKIP_SYNC, advertised for non-NULL DMA ops. Then later, if/when swiotlb is used for the first time, the flag is reset back to on, from swiotlb_tbl_map_single(). On iavf, the UDP trafficgen with XDP_DROP in skb mode test shows +3-5% increase for direct DMA. Suggested-by: Christoph Hellwig # direct DMA shortcut Co-developed-by: Eric Dumazet Signed-off-by: Eric Dumazet Signed-off-by: Alexander Lobakin Signed-off-by: Christoph Hellwig --- include/linux/device.h | 4 ++++ include/linux/dma-map-ops.h | 12 ++++++++++ include/linux/dma-mapping.h | 53 ++++++++++++++++++++++++++++++++++++++----- kernel/dma/mapping.c | 55 +++++++++++++++++++++++++++++++++++---------- kernel/dma/swiotlb.c | 6 +++++ 5 files changed, 113 insertions(+), 17 deletions(-) (limited to 'kernel/dma/mapping.c') diff --git a/include/linux/device.h b/include/linux/device.h index b9f5464f44ed..ed95b829f05b 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -691,6 +691,7 @@ struct device_physical_location { * and optionall (if the coherent mask is large enough) also * for dma allocations. This flag is managed by the dma ops * instance from ->dma_supported. + * @dma_need_sync: The device needs performing DMA sync operations. * * At the lowest level, every device in a Linux system is represented by an * instance of struct device. The device structure contains the information @@ -803,6 +804,9 @@ struct device { #ifdef CONFIG_DMA_OPS_BYPASS bool dma_ops_bypass : 1; #endif +#ifdef CONFIG_DMA_NEED_SYNC + bool dma_need_sync:1; +#endif }; /** diff --git a/include/linux/dma-map-ops.h b/include/linux/dma-map-ops.h index 4abc60f04209..4893cb89cb52 100644 --- a/include/linux/dma-map-ops.h +++ b/include/linux/dma-map-ops.h @@ -18,8 +18,11 @@ struct iommu_ops; * * DMA_F_PCI_P2PDMA_SUPPORTED: Indicates the dma_map_ops implementation can * handle PCI P2PDMA pages in the map_sg/unmap_sg operation. + * DMA_F_CAN_SKIP_SYNC: DMA sync operations can be skipped if the device is + * coherent and it's not an SWIOTLB buffer. */ #define DMA_F_PCI_P2PDMA_SUPPORTED (1 << 0) +#define DMA_F_CAN_SKIP_SYNC (1 << 1) struct dma_map_ops { unsigned int flags; @@ -273,6 +276,15 @@ static inline bool dev_is_dma_coherent(struct device *dev) } #endif /* CONFIG_ARCH_HAS_DMA_COHERENCE_H */ +static inline void dma_reset_need_sync(struct device *dev) +{ +#ifdef CONFIG_DMA_NEED_SYNC + /* Reset it only once so that the function can be called on hotpath */ + if (unlikely(!dev->dma_need_sync)) + dev->dma_need_sync = true; +#endif +} + /* * Check whether potential kmalloc() buffers are safe for non-coherent DMA. */ diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index a569b56b25e2..eb4e15893b6c 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -282,16 +282,59 @@ static inline int dma_mmap_noncontiguous(struct device *dev, #endif /* CONFIG_HAS_DMA */ #if defined(CONFIG_HAS_DMA) && defined(CONFIG_DMA_NEED_SYNC) -void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size, +void __dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size, enum dma_data_direction dir); -void dma_sync_single_for_device(struct device *dev, dma_addr_t addr, +void __dma_sync_single_for_device(struct device *dev, dma_addr_t addr, size_t size, enum dma_data_direction dir); -void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, +void __dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nelems, enum dma_data_direction dir); -void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, +void __dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nelems, enum dma_data_direction dir); -bool dma_need_sync(struct device *dev, dma_addr_t dma_addr); +bool __dma_need_sync(struct device *dev, dma_addr_t dma_addr); + +static inline bool dma_dev_need_sync(const struct device *dev) +{ + /* Always call DMA sync operations when debugging is enabled */ + return dev->dma_need_sync || IS_ENABLED(CONFIG_DMA_API_DEBUG); +} + +static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, + size_t size, enum dma_data_direction dir) +{ + if (dma_dev_need_sync(dev)) + __dma_sync_single_for_cpu(dev, addr, size, dir); +} + +static inline void dma_sync_single_for_device(struct device *dev, + dma_addr_t addr, size_t size, enum dma_data_direction dir) +{ + if (dma_dev_need_sync(dev)) + __dma_sync_single_for_device(dev, addr, size, dir); +} + +static inline void dma_sync_sg_for_cpu(struct device *dev, + struct scatterlist *sg, int nelems, enum dma_data_direction dir) +{ + if (dma_dev_need_sync(dev)) + __dma_sync_sg_for_cpu(dev, sg, nelems, dir); +} + +static inline void dma_sync_sg_for_device(struct device *dev, + struct scatterlist *sg, int nelems, enum dma_data_direction dir) +{ + if (dma_dev_need_sync(dev)) + __dma_sync_sg_for_device(dev, sg, nelems, dir); +} + +static inline bool dma_need_sync(struct device *dev, dma_addr_t dma_addr) +{ + return dma_dev_need_sync(dev) ? __dma_need_sync(dev, dma_addr) : false; +} #else /* !CONFIG_HAS_DMA || !CONFIG_DMA_NEED_SYNC */ +static inline bool dma_dev_need_sync(const struct device *dev) +{ + return false; +} static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size, enum dma_data_direction dir) { diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index c78b78e95a26..3524bc92c37f 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -330,7 +330,7 @@ void dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size, EXPORT_SYMBOL(dma_unmap_resource); #ifdef CONFIG_DMA_NEED_SYNC -void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size, +void __dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size, enum dma_data_direction dir) { const struct dma_map_ops *ops = get_dma_ops(dev); @@ -342,9 +342,9 @@ void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size, ops->sync_single_for_cpu(dev, addr, size, dir); debug_dma_sync_single_for_cpu(dev, addr, size, dir); } -EXPORT_SYMBOL(dma_sync_single_for_cpu); +EXPORT_SYMBOL(__dma_sync_single_for_cpu); -void dma_sync_single_for_device(struct device *dev, dma_addr_t addr, +void __dma_sync_single_for_device(struct device *dev, dma_addr_t addr, size_t size, enum dma_data_direction dir) { const struct dma_map_ops *ops = get_dma_ops(dev); @@ -356,9 +356,9 @@ void dma_sync_single_for_device(struct device *dev, dma_addr_t addr, ops->sync_single_for_device(dev, addr, size, dir); debug_dma_sync_single_for_device(dev, addr, size, dir); } -EXPORT_SYMBOL(dma_sync_single_for_device); +EXPORT_SYMBOL(__dma_sync_single_for_device); -void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, +void __dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nelems, enum dma_data_direction dir) { const struct dma_map_ops *ops = get_dma_ops(dev); @@ -370,9 +370,9 @@ void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, ops->sync_sg_for_cpu(dev, sg, nelems, dir); debug_dma_sync_sg_for_cpu(dev, sg, nelems, dir); } -EXPORT_SYMBOL(dma_sync_sg_for_cpu); +EXPORT_SYMBOL(__dma_sync_sg_for_cpu); -void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, +void __dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nelems, enum dma_data_direction dir) { const struct dma_map_ops *ops = get_dma_ops(dev); @@ -384,18 +384,47 @@ void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, ops->sync_sg_for_device(dev, sg, nelems, dir); debug_dma_sync_sg_for_device(dev, sg, nelems, dir); } -EXPORT_SYMBOL(dma_sync_sg_for_device); +EXPORT_SYMBOL(__dma_sync_sg_for_device); -bool dma_need_sync(struct device *dev, dma_addr_t dma_addr) +bool __dma_need_sync(struct device *dev, dma_addr_t dma_addr) { const struct dma_map_ops *ops = get_dma_ops(dev); if (dma_map_direct(dev, ops)) + /* + * dma_need_sync could've been reset on first SWIOTLB buffer + * mapping, but @dma_addr is not necessary an SWIOTLB buffer. + * In this case, fall back to more granular check. + */ return dma_direct_need_sync(dev, dma_addr); - return ops->sync_single_for_cpu || ops->sync_single_for_device; + return true; } -EXPORT_SYMBOL_GPL(dma_need_sync); -#endif /* CONFIG_DMA_NEED_SYNC */ +EXPORT_SYMBOL_GPL(__dma_need_sync); + +static void dma_setup_need_sync(struct device *dev) +{ + const struct dma_map_ops *ops = get_dma_ops(dev); + + if (dma_map_direct(dev, ops) || (ops->flags & DMA_F_CAN_SKIP_SYNC)) + /* + * dma_need_sync will be reset to %true on first SWIOTLB buffer + * mapping, if any. During the device initialization, it's + * enough to check only for the DMA coherence. + */ + dev->dma_need_sync = !dev_is_dma_coherent(dev); + else if (!ops->sync_single_for_device && !ops->sync_single_for_cpu && + !ops->sync_sg_for_device && !ops->sync_sg_for_cpu) + /* + * Synchronization is not possible when none of DMA sync ops + * is set. + */ + dev->dma_need_sync = false; + else + dev->dma_need_sync = true; +} +#else /* !CONFIG_DMA_NEED_SYNC */ +static inline void dma_setup_need_sync(struct device *dev) { } +#endif /* !CONFIG_DMA_NEED_SYNC */ /* * The whole dma_get_sgtable() idea is fundamentally unsafe - it seems @@ -785,6 +814,8 @@ int dma_set_mask(struct device *dev, u64 mask) arch_dma_set_mask(dev, mask); *dev->dma_mask = mask; + dma_setup_need_sync(dev); + return 0; } EXPORT_SYMBOL(dma_set_mask); diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 046da973a7e2..ae3e593eaadb 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -1408,6 +1408,12 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr, return (phys_addr_t)DMA_MAPPING_ERROR; } + /* + * If dma_need_sync wasn't set, reset it on first SWIOTLB buffer + * mapping to always sync SWIOTLB buffers. + */ + dma_reset_need_sync(dev); + /* * Save away the mapping from the original address to the DMA address. * This is needed when we sync the memory. Then we sync the buffer if -- cgit v1.2.3-59-g8ed1b From a6016aac5252da9d22a4dc0b98121b0acdf6d2f5 Mon Sep 17 00:00:00 2001 From: Alexander Lobakin Date: Thu, 9 May 2024 16:46:16 +0200 Subject: dma: fix DMA sync for drivers not calling dma_set_mask*() There are several reports that the DMA sync shortcut broke non-coherent devices. dev->dma_need_sync is false after the &device allocation and if a driver didn't call dma_set_mask*(), it will still be false even if the device is not DMA-coherent and thus needs synchronizing. Due to historical reasons, there's still a lot of drivers not calling it. Invert the boolean, so that the sync will be performed by default and the shortcut will be enabled only when calling dma_set_mask*(). Reported-by: Steven Price Closes: https://lore.kernel.org/lkml/010686f5-3049-46a1-8230-7752a1b433ff@arm.com Reported-by: Marek Szyprowski Closes: https://lore.kernel.org/lkml/46160534-5003-4809-a408-6b3a3f4921e9@samsung.com Fixes: f406c8e4b770. ("dma: avoid redundant calls for sync operations") Signed-off-by: Alexander Lobakin Signed-off-by: Christoph Hellwig Tested-by: Steven Price Tested-by: Marek Szyprowski --- include/linux/device.h | 4 ++-- include/linux/dma-map-ops.h | 4 ++-- include/linux/dma-mapping.h | 2 +- kernel/dma/mapping.c | 10 +++++----- kernel/dma/swiotlb.c | 2 +- 5 files changed, 11 insertions(+), 11 deletions(-) (limited to 'kernel/dma/mapping.c') diff --git a/include/linux/device.h b/include/linux/device.h index ed95b829f05b..d4b50accff26 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -691,7 +691,7 @@ struct device_physical_location { * and optionall (if the coherent mask is large enough) also * for dma allocations. This flag is managed by the dma ops * instance from ->dma_supported. - * @dma_need_sync: The device needs performing DMA sync operations. + * @dma_skip_sync: DMA sync operations can be skipped for coherent buffers. * * At the lowest level, every device in a Linux system is represented by an * instance of struct device. The device structure contains the information @@ -805,7 +805,7 @@ struct device { bool dma_ops_bypass : 1; #endif #ifdef CONFIG_DMA_NEED_SYNC - bool dma_need_sync:1; + bool dma_skip_sync:1; #endif }; diff --git a/include/linux/dma-map-ops.h b/include/linux/dma-map-ops.h index 4893cb89cb52..5217b922d29f 100644 --- a/include/linux/dma-map-ops.h +++ b/include/linux/dma-map-ops.h @@ -280,8 +280,8 @@ static inline void dma_reset_need_sync(struct device *dev) { #ifdef CONFIG_DMA_NEED_SYNC /* Reset it only once so that the function can be called on hotpath */ - if (unlikely(!dev->dma_need_sync)) - dev->dma_need_sync = true; + if (unlikely(dev->dma_skip_sync)) + dev->dma_skip_sync = false; #endif } diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index eb4e15893b6c..f693aafe221f 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -295,7 +295,7 @@ bool __dma_need_sync(struct device *dev, dma_addr_t dma_addr); static inline bool dma_dev_need_sync(const struct device *dev) { /* Always call DMA sync operations when debugging is enabled */ - return dev->dma_need_sync || IS_ENABLED(CONFIG_DMA_API_DEBUG); + return !dev->dma_skip_sync || IS_ENABLED(CONFIG_DMA_API_DEBUG); } static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index 3524bc92c37f..3f77c3f8d16d 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -392,7 +392,7 @@ bool __dma_need_sync(struct device *dev, dma_addr_t dma_addr) if (dma_map_direct(dev, ops)) /* - * dma_need_sync could've been reset on first SWIOTLB buffer + * dma_skip_sync could've been reset on first SWIOTLB buffer * mapping, but @dma_addr is not necessary an SWIOTLB buffer. * In this case, fall back to more granular check. */ @@ -407,20 +407,20 @@ static void dma_setup_need_sync(struct device *dev) if (dma_map_direct(dev, ops) || (ops->flags & DMA_F_CAN_SKIP_SYNC)) /* - * dma_need_sync will be reset to %true on first SWIOTLB buffer + * dma_skip_sync will be reset to %false on first SWIOTLB buffer * mapping, if any. During the device initialization, it's * enough to check only for the DMA coherence. */ - dev->dma_need_sync = !dev_is_dma_coherent(dev); + dev->dma_skip_sync = dev_is_dma_coherent(dev); else if (!ops->sync_single_for_device && !ops->sync_single_for_cpu && !ops->sync_sg_for_device && !ops->sync_sg_for_cpu) /* * Synchronization is not possible when none of DMA sync ops * is set. */ - dev->dma_need_sync = false; + dev->dma_skip_sync = true; else - dev->dma_need_sync = true; + dev->dma_skip_sync = false; } #else /* !CONFIG_DMA_NEED_SYNC */ static inline void dma_setup_need_sync(struct device *dev) { } diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index ae3e593eaadb..068134697cf1 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -1409,7 +1409,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr, } /* - * If dma_need_sync wasn't set, reset it on first SWIOTLB buffer + * If dma_skip_sync was set, reset it on first SWIOTLB buffer * mapping to always sync SWIOTLB buffers. */ dma_reset_need_sync(dev); -- cgit v1.2.3-59-g8ed1b