diff options
| -rw-r--r-- | include/linux/device.h | 8 | ||||
| -rw-r--r-- | kernel/dma/Kconfig | 8 | ||||
| -rw-r--r-- | kernel/dma/mapping.c | 74 |
3 files changed, 68 insertions, 22 deletions
diff --git a/include/linux/device.h b/include/linux/device.h index 4c4af98321eb..1f71acf37f78 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -523,6 +523,11 @@ struct dev_links_info { * sync_state() callback. * @dma_coherent: this particular device is dma coherent, even if the * architecture supports non-coherent devices. + * @dma_ops_bypass: If set to %true then the dma_ops are bypassed for the + * streaming DMA operations (->map_* / ->unmap_* / ->sync_*), + * 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. * * At the lowest level, every device in a Linux system is represented by an * instance of struct device. The device structure contains the information @@ -623,6 +628,9 @@ struct device { defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) bool dma_coherent:1; #endif +#ifdef CONFIG_DMA_OPS_BYPASS + bool dma_ops_bypass : 1; +#endif }; static inline struct device *kobj_to_dev(struct kobject *kobj) diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig index 5cfb2428593a..f4770fcfa62b 100644 --- a/kernel/dma/Kconfig +++ b/kernel/dma/Kconfig @@ -8,6 +8,14 @@ config HAS_DMA config DMA_OPS bool +# +# IOMMU drivers that can bypass the IOMMU code and optionally use the direct +# mapping fast path should select this option and set the dma_ops_bypass +# flag in struct device where applicable +# +config DMA_OPS_BYPASS + bool + config NEED_SG_DMA_LENGTH bool diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index b53953024512..0d129421e75f 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -105,9 +105,35 @@ void *dmam_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle, } EXPORT_SYMBOL(dmam_alloc_attrs); -static inline bool dma_is_direct(const struct dma_map_ops *ops) +static bool dma_go_direct(struct device *dev, dma_addr_t mask, + const struct dma_map_ops *ops) { - return likely(!ops); + if (likely(!ops)) + return true; +#ifdef CONFIG_DMA_OPS_BYPASS + if (dev->dma_ops_bypass) + return min_not_zero(mask, dev->bus_dma_limit) >= + dma_direct_get_required_mask(dev); +#endif + return false; +} + + +/* + * Check if the devices uses a direct mapping for streaming DMA operations. + * This allows IOMMU drivers to set a bypass mode if the DMA mask is large + * enough. + */ +static inline bool dma_alloc_direct(struct device *dev, + const struct dma_map_ops *ops) +{ + return dma_go_direct(dev, dev->coherent_dma_mask, ops); +} + +static inline bool dma_map_direct(struct device *dev, + const struct dma_map_ops *ops) +{ + return dma_go_direct(dev, *dev->dma_mask, ops); } dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page, @@ -118,7 +144,7 @@ dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page, dma_addr_t addr; BUG_ON(!valid_dma_direction(dir)); - if (dma_is_direct(ops)) + if (dma_map_direct(dev, ops)) addr = dma_direct_map_page(dev, page, offset, size, dir, attrs); else addr = ops->map_page(dev, page, offset, size, dir, attrs); @@ -134,7 +160,7 @@ void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size, const struct dma_map_ops *ops = get_dma_ops(dev); BUG_ON(!valid_dma_direction(dir)); - if (dma_is_direct(ops)) + if (dma_map_direct(dev, ops)) dma_direct_unmap_page(dev, addr, size, dir, attrs); else if (ops->unmap_page) ops->unmap_page(dev, addr, size, dir, attrs); @@ -153,7 +179,7 @@ int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, int nents, int ents; BUG_ON(!valid_dma_direction(dir)); - if (dma_is_direct(ops)) + if (dma_map_direct(dev, ops)) ents = dma_direct_map_sg(dev, sg, nents, dir, attrs); else ents = ops->map_sg(dev, sg, nents, dir, attrs); @@ -172,7 +198,7 @@ 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 (dma_is_direct(ops)) + if (dma_map_direct(dev, ops)) dma_direct_unmap_sg(dev, sg, nents, dir, attrs); else if (ops->unmap_sg) ops->unmap_sg(dev, sg, nents, dir, attrs); @@ -191,7 +217,7 @@ dma_addr_t dma_map_resource(struct device *dev, phys_addr_t phys_addr, if (WARN_ON_ONCE(pfn_valid(PHYS_PFN(phys_addr)))) return DMA_MAPPING_ERROR; - if (dma_is_direct(ops)) + if (dma_map_direct(dev, ops)) addr = dma_direct_map_resource(dev, phys_addr, size, dir, attrs); else if (ops->map_resource) addr = ops->map_resource(dev, phys_addr, size, dir, attrs); @@ -207,7 +233,7 @@ void dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size, const struct dma_map_ops *ops = get_dma_ops(dev); BUG_ON(!valid_dma_direction(dir)); - if (!dma_is_direct(ops) && ops->unmap_resource) + if (!dma_map_direct(dev, ops) && ops->unmap_resource) ops->unmap_resource(dev, addr, size, dir, attrs); debug_dma_unmap_resource(dev, addr, size, dir); } @@ -219,7 +245,7 @@ void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size, const struct dma_map_ops *ops = get_dma_ops(dev); BUG_ON(!valid_dma_direction(dir)); - if (dma_is_direct(ops)) + if (dma_map_direct(dev, 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); @@ -233,7 +259,7 @@ void dma_sync_single_for_device(struct device *dev, dma_addr_t addr, const struct dma_map_ops *ops = get_dma_ops(dev); BUG_ON(!valid_dma_direction(dir)); - if (dma_is_direct(ops)) + if (dma_map_direct(dev, 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); @@ -247,7 +273,7 @@ void 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 (dma_is_direct(ops)) + if (dma_map_direct(dev, 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); @@ -261,7 +287,7 @@ void 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 (dma_is_direct(ops)) + if (dma_map_direct(dev, 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); @@ -302,7 +328,7 @@ int dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt, { const struct dma_map_ops *ops = get_dma_ops(dev); - if (dma_is_direct(ops)) + if (dma_alloc_direct(dev, ops)) return dma_direct_get_sgtable(dev, sgt, cpu_addr, dma_addr, size, attrs); if (!ops->get_sgtable) @@ -372,7 +398,7 @@ bool dma_can_mmap(struct device *dev) { const struct dma_map_ops *ops = get_dma_ops(dev); - if (dma_is_direct(ops)) + if (dma_alloc_direct(dev, ops)) return dma_direct_can_mmap(dev); return ops->mmap != NULL; } @@ -397,7 +423,7 @@ int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma, { const struct dma_map_ops *ops = get_dma_ops(dev); - if (dma_is_direct(ops)) + if (dma_alloc_direct(dev, ops)) return dma_direct_mmap(dev, vma, cpu_addr, dma_addr, size, attrs); if (!ops->mmap) @@ -410,7 +436,7 @@ u64 dma_get_required_mask(struct device *dev) { const struct dma_map_ops *ops = get_dma_ops(dev); - if (dma_is_direct(ops)) + if (dma_alloc_direct(dev, ops)) return dma_direct_get_required_mask(dev); if (ops->get_required_mask) return ops->get_required_mask(dev); @@ -441,7 +467,7 @@ void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle, /* let the implementation decide on the zone to allocate from: */ flag &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM); - if (dma_is_direct(ops)) + if (dma_alloc_direct(dev, 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); @@ -473,7 +499,7 @@ void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr, return; debug_dma_free_coherent(dev, size, cpu_addr, dma_handle); - if (dma_is_direct(ops)) + if (dma_alloc_direct(dev, ops)) dma_direct_free(dev, size, cpu_addr, dma_handle, attrs); else if (ops->free) ops->free(dev, size, cpu_addr, dma_handle, attrs); @@ -484,7 +510,11 @@ int dma_supported(struct device *dev, u64 mask) { const struct dma_map_ops *ops = get_dma_ops(dev); - if (dma_is_direct(ops)) + /* + * ->dma_supported sets the bypass flag, so we must always call + * into the method here unless the device is truly direct mapped. + */ + if (!ops) return dma_direct_supported(dev, mask); if (!ops->dma_supported) return 1; @@ -540,7 +570,7 @@ void dma_cache_sync(struct device *dev, void *vaddr, size_t size, BUG_ON(!valid_dma_direction(dir)); - if (dma_is_direct(ops)) + if (dma_alloc_direct(dev, ops)) arch_dma_cache_sync(dev, vaddr, size, dir); else if (ops->cache_sync) ops->cache_sync(dev, vaddr, size, dir); @@ -552,7 +582,7 @@ size_t dma_max_mapping_size(struct device *dev) const struct dma_map_ops *ops = get_dma_ops(dev); size_t size = SIZE_MAX; - if (dma_is_direct(ops)) + if (dma_map_direct(dev, ops)) size = dma_direct_max_mapping_size(dev); else if (ops && ops->max_mapping_size) size = ops->max_mapping_size(dev); @@ -565,7 +595,7 @@ bool dma_need_sync(struct device *dev, dma_addr_t dma_addr) { const struct dma_map_ops *ops = get_dma_ops(dev); - if (dma_is_direct(ops)) + 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; } |