[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [RFC PATCH v3 4/6] swiotlb: Add restricted DMA alloc/free support.
Add the functions, swiotlb_alloc and swiotlb_free to support the memory allocation from restricted DMA pool. Signed-off-by: Claire Chang <tientzu@xxxxxxxxxxxx> --- include/linux/swiotlb.h | 6 ++ kernel/dma/direct.c | 12 +++ kernel/dma/swiotlb.c | 171 +++++++++++++++++++++++++++++----------- 3 files changed, 144 insertions(+), 45 deletions(-) diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index 5135e5636042..84fe96e40685 100644 --- a/include/linux/swiotlb.h +++ b/include/linux/swiotlb.h @@ -68,6 +68,12 @@ extern void swiotlb_tbl_sync_single(struct device *hwdev, dma_addr_t swiotlb_map(struct device *dev, phys_addr_t phys, size_t size, enum dma_data_direction dir, unsigned long attrs); +void *swiotlb_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, + unsigned long attrs); + +void swiotlb_free(struct device *dev, size_t size, void *vaddr, + dma_addr_t dma_addr, unsigned long attrs); + #ifdef CONFIG_SWIOTLB extern enum swiotlb_force swiotlb_force; diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 30ccbc08e229..126e9b3354d6 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -137,6 +137,11 @@ void *dma_direct_alloc(struct device *dev, size_t size, void *ret; int err; +#ifdef CONFIG_SWIOTLB + if (unlikely(dev->dma_io_tlb_mem)) + return swiotlb_alloc(dev, size, dma_handle, attrs); +#endif + size = PAGE_ALIGN(size); if (attrs & DMA_ATTR_NO_WARN) gfp |= __GFP_NOWARN; @@ -246,6 +251,13 @@ void dma_direct_free(struct device *dev, size_t size, { unsigned int page_order = get_order(size); +#ifdef CONFIG_SWIOTLB + if (unlikely(dev->dma_io_tlb_mem)) { + swiotlb_free(dev, size, cpu_addr, dma_addr, attrs); + return; + } +#endif + if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) && !force_dma_unencrypted(dev)) { /* cpu_addr is a struct page cookie, not a kernel address */ diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 1f05af09e61a..ca88ef59435d 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -459,14 +459,13 @@ static void swiotlb_bounce(phys_addr_t orig_addr, phys_addr_t tlb_addr, } } -phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, phys_addr_t orig_addr, - size_t mapping_size, size_t alloc_size, - enum dma_data_direction dir, unsigned long attrs) +static int swiotlb_tbl_find_free_region(struct device *hwdev, + dma_addr_t tbl_dma_addr, + size_t alloc_size, + unsigned long attrs) { struct io_tlb_mem *mem = get_io_tlb_mem(hwdev); - dma_addr_t tbl_dma_addr = phys_to_dma_unencrypted(hwdev, mem->start); unsigned long flags; - phys_addr_t tlb_addr; unsigned int nslots, stride, index, wrap; int i; unsigned long mask; @@ -477,15 +476,6 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, phys_addr_t orig_addr, if (no_iotlb_memory && !hwdev->dma_io_tlb_mem) panic("Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer"); - if (mem_encrypt_active()) - pr_warn_once("Memory encryption is active and system is using DMA bounce buffers\n"); - - if (mapping_size > alloc_size) { - dev_warn_once(hwdev, "Invalid sizes (mapping: %zd bytes, alloc: %zd bytes)", - mapping_size, alloc_size); - return (phys_addr_t)DMA_MAPPING_ERROR; - } - mask = dma_get_seg_boundary(hwdev); tbl_dma_addr &= mask; @@ -547,7 +537,6 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, phys_addr_t orig_addr, mem->list[i] = 0; for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE - 1) && mem->list[i]; i--) mem->list[i] = ++count; - tlb_addr = mem->start + (index << IO_TLB_SHIFT); /* * Update the indices to avoid searching in the next @@ -570,45 +559,21 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, phys_addr_t orig_addr, if (!(attrs & DMA_ATTR_NO_WARN) && printk_ratelimit()) dev_warn(hwdev, "swiotlb buffer is full (sz: %zd bytes), total %lu (slots), used %lu (slots)\n", alloc_size, mem->nslabs, tmp_io_tlb_used); - return (phys_addr_t)DMA_MAPPING_ERROR; + return -ENOMEM; + found: mem->used += nslots; spin_unlock_irqrestore(&mem->lock, flags); - /* - * 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 - * needed. - */ - for (i = 0; i < nslots; i++) - mem->orig_addr[index+i] = orig_addr + (i << IO_TLB_SHIFT); - if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) && - (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)) - swiotlb_bounce(orig_addr, tlb_addr, mapping_size, DMA_TO_DEVICE); - - return tlb_addr; + return index; } -/* - * tlb_addr is the physical address of the bounce buffer to unmap. - */ -void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr, - size_t mapping_size, size_t alloc_size, - enum dma_data_direction dir, unsigned long attrs) +static void swiotlb_tbl_release_region(struct device *hwdev, int index, + size_t size) { struct io_tlb_mem *mem = get_io_tlb_mem(hwdev); unsigned long flags; - int i, count, nslots = ALIGN(alloc_size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT; - int index = (tlb_addr - mem->start) >> IO_TLB_SHIFT; - phys_addr_t orig_addr = mem->orig_addr[index]; - - /* - * First, sync the memory before unmapping the entry - */ - if (orig_addr != INVALID_PHYS_ADDR && - !(attrs & DMA_ATTR_SKIP_CPU_SYNC) && - ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL))) - swiotlb_bounce(orig_addr, tlb_addr, mapping_size, DMA_FROM_DEVICE); + int i, count, nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT; /* * Return the buffer to the free list by setting the corresponding @@ -640,6 +605,69 @@ void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr, spin_unlock_irqrestore(&mem->lock, flags); } +phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, phys_addr_t orig_addr, + size_t mapping_size, size_t alloc_size, + enum dma_data_direction dir, unsigned long attrs) +{ + struct io_tlb_mem *mem = get_io_tlb_mem(hwdev); + dma_addr_t tbl_dma_addr = phys_to_dma_unencrypted(hwdev, mem->start); + phys_addr_t tlb_addr; + unsigned int nslots, index; + int i; + + if (mem_encrypt_active()) + pr_warn_once("Memory encryption is active and system is using DMA bounce buffers\n"); + + if (mapping_size > alloc_size) { + dev_warn_once(hwdev, "Invalid sizes (mapping: %zd bytes, alloc: %zd bytes)", + mapping_size, alloc_size); + return (phys_addr_t)DMA_MAPPING_ERROR; + } + + index = swiotlb_tbl_find_free_region(hwdev, tbl_dma_addr, alloc_size, + attrs); + if (index < 0) + return (phys_addr_t)DMA_MAPPING_ERROR; + + tlb_addr = mem->start + (index << IO_TLB_SHIFT); + + /* + * 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 + * needed. + */ + nslots = ALIGN(alloc_size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT; + for (i = 0; i < nslots; i++) + mem->orig_addr[index+i] = orig_addr + (i << IO_TLB_SHIFT); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) && + (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)) + swiotlb_bounce(orig_addr, tlb_addr, mapping_size, DMA_TO_DEVICE); + + return tlb_addr; +} + +/* + * tlb_addr is the physical address of the bounce buffer to unmap. + */ +void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr, + size_t mapping_size, size_t alloc_size, + enum dma_data_direction dir, unsigned long attrs) +{ + struct io_tlb_mem *mem = get_io_tlb_mem(hwdev); + int index = (tlb_addr - mem->start) >> IO_TLB_SHIFT; + phys_addr_t orig_addr = mem->orig_addr[index]; + + /* + * First, sync the memory before unmapping the entry + */ + if (orig_addr != INVALID_PHYS_ADDR && + !(attrs & DMA_ATTR_SKIP_CPU_SYNC) && + ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL))) + swiotlb_bounce(orig_addr, tlb_addr, mapping_size, DMA_FROM_DEVICE); + + swiotlb_tbl_release_region(hwdev, index, alloc_size); +} + void swiotlb_tbl_sync_single(struct device *hwdev, phys_addr_t tlb_addr, size_t size, enum dma_data_direction dir, enum dma_sync_target target) @@ -706,6 +734,59 @@ dma_addr_t swiotlb_map(struct device *dev, phys_addr_t paddr, size_t size, return dma_addr; } +void *swiotlb_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, + unsigned long attrs) +{ + struct io_tlb_mem *mem = dev->dma_io_tlb_mem; + int index; + void *vaddr; + phys_addr_t tlb_addr; + + size = PAGE_ALIGN(size); + index = swiotlb_tbl_find_free_region(dev, mem->start, size, attrs); + if (index < 0) + return NULL; + + tlb_addr = mem->start + (index << IO_TLB_SHIFT); + *dma_handle = phys_to_dma_unencrypted(dev, tlb_addr); + + if (!dev_is_dma_coherent(dev)) { + unsigned long pfn = PFN_DOWN(tlb_addr); + + /* remove any dirty cache lines on the kernel alias */ + arch_dma_prep_coherent(pfn_to_page(pfn), size); + + /* create a coherent mapping */ + vaddr = dma_common_contiguous_remap( + pfn_to_page(pfn), size, + dma_pgprot(dev, PAGE_KERNEL, attrs), + __builtin_return_address(0)); + if (!vaddr) { + swiotlb_tbl_release_region(dev, index, size); + return NULL; + } + } else { + vaddr = phys_to_virt(tlb_addr); + } + + memset(vaddr, 0, size); + + return vaddr; +} + +void swiotlb_free(struct device *dev, size_t size, void *vaddr, + dma_addr_t dma_addr, unsigned long attrs) +{ + struct io_tlb_mem *mem = dev->dma_io_tlb_mem; + unsigned int index; + + if (!dev_is_dma_coherent(dev)) + vunmap(vaddr); + + index = (dma_addr - mem->start) >> IO_TLB_SHIFT; + swiotlb_tbl_release_region(dev, index, PAGE_ALIGN(size)); +} + size_t swiotlb_max_mapping_size(struct device *dev) { return ((size_t)1 << IO_TLB_SHIFT) * IO_TLB_SEGSIZE; -- 2.29.2.729.g45daf8777d-goog
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