From 92d420ec028d24f18ce194149bd0a0a7c42029a3 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Mon, 21 Dec 2015 19:31:33 +0100 Subject: [PATCH] iommu/amd: Relax locking in dma_ops path Remove the long holding times of the domain->lock and rely on the bitmap_lock instead. Signed-off-by: Joerg Roedel --- drivers/iommu/amd_iommu.c | 70 ++++++--------------------------------- 1 file changed, 11 insertions(+), 59 deletions(-) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 11ee8855a2e0..e98a466faabf 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -1466,8 +1466,10 @@ static int alloc_new_range(struct dma_ops_domain *dma_dom, } } + spin_lock_irqsave(&dma_dom->domain.lock, flags); + /* First take the bitmap_lock and then publish the range */ - spin_lock_irqsave(&range->bitmap_lock, flags); + spin_lock(&range->bitmap_lock); old_size = dma_dom->aperture_size; dma_dom->aperture[index] = range; @@ -1518,7 +1520,9 @@ static int alloc_new_range(struct dma_ops_domain *dma_dom, update_domain(&dma_dom->domain); - spin_unlock_irqrestore(&range->bitmap_lock, flags); + spin_unlock(&range->bitmap_lock); + + spin_unlock_irqrestore(&dma_dom->domain.lock, flags); return 0; @@ -2562,11 +2566,9 @@ static dma_addr_t map_page(struct device *dev, struct page *page, enum dma_data_direction dir, struct dma_attrs *attrs) { - unsigned long flags; + phys_addr_t paddr = page_to_phys(page) + offset; struct protection_domain *domain; - dma_addr_t addr; u64 dma_mask; - phys_addr_t paddr = page_to_phys(page) + offset; INC_STATS_COUNTER(cnt_map_single); @@ -2578,19 +2580,8 @@ static dma_addr_t map_page(struct device *dev, struct page *page, dma_mask = *dev->dma_mask; - spin_lock_irqsave(&domain->lock, flags); - - addr = __map_single(dev, domain->priv, paddr, size, dir, false, + return __map_single(dev, domain->priv, paddr, size, dir, false, dma_mask); - if (addr == DMA_ERROR_CODE) - goto out; - - domain_flush_complete(domain); - -out: - spin_unlock_irqrestore(&domain->lock, flags); - - return addr; } /* @@ -2599,7 +2590,6 @@ out: static void unmap_page(struct device *dev, dma_addr_t dma_addr, size_t size, enum dma_data_direction dir, struct dma_attrs *attrs) { - unsigned long flags; struct protection_domain *domain; INC_STATS_COUNTER(cnt_unmap_single); @@ -2608,13 +2598,7 @@ static void unmap_page(struct device *dev, dma_addr_t dma_addr, size_t size, if (IS_ERR(domain)) return; - spin_lock_irqsave(&domain->lock, flags); - __unmap_single(domain->priv, dma_addr, size, dir); - - domain_flush_complete(domain); - - spin_unlock_irqrestore(&domain->lock, flags); } /* @@ -2625,7 +2609,6 @@ static int map_sg(struct device *dev, struct scatterlist *sglist, int nelems, enum dma_data_direction dir, struct dma_attrs *attrs) { - unsigned long flags; struct protection_domain *domain; int i; struct scatterlist *s; @@ -2641,8 +2624,6 @@ static int map_sg(struct device *dev, struct scatterlist *sglist, dma_mask = *dev->dma_mask; - spin_lock_irqsave(&domain->lock, flags); - for_each_sg(sglist, s, nelems, i) { paddr = sg_phys(s); @@ -2657,12 +2638,8 @@ static int map_sg(struct device *dev, struct scatterlist *sglist, goto unmap; } - domain_flush_complete(domain); - -out: - spin_unlock_irqrestore(&domain->lock, flags); - return mapped_elems; + unmap: for_each_sg(sglist, s, mapped_elems, i) { if (s->dma_address) @@ -2671,9 +2648,7 @@ unmap: s->dma_address = s->dma_length = 0; } - mapped_elems = 0; - - goto out; + return 0; } /* @@ -2684,7 +2659,6 @@ static void unmap_sg(struct device *dev, struct scatterlist *sglist, int nelems, enum dma_data_direction dir, struct dma_attrs *attrs) { - unsigned long flags; struct protection_domain *domain; struct scatterlist *s; int i; @@ -2695,17 +2669,11 @@ static void unmap_sg(struct device *dev, struct scatterlist *sglist, if (IS_ERR(domain)) return; - spin_lock_irqsave(&domain->lock, flags); - for_each_sg(sglist, s, nelems, i) { __unmap_single(domain->priv, s->dma_address, s->dma_length, dir); s->dma_address = s->dma_length = 0; } - - domain_flush_complete(domain); - - spin_unlock_irqrestore(&domain->lock, flags); } /* @@ -2717,7 +2685,6 @@ static void *alloc_coherent(struct device *dev, size_t size, { u64 dma_mask = dev->coherent_dma_mask; struct protection_domain *domain; - unsigned long flags; struct page *page; INC_STATS_COUNTER(cnt_alloc_coherent); @@ -2749,19 +2716,11 @@ static void *alloc_coherent(struct device *dev, size_t size, if (!dma_mask) dma_mask = *dev->dma_mask; - spin_lock_irqsave(&domain->lock, flags); - *dma_addr = __map_single(dev, domain->priv, page_to_phys(page), size, DMA_BIDIRECTIONAL, true, dma_mask); - if (*dma_addr == DMA_ERROR_CODE) { - spin_unlock_irqrestore(&domain->lock, flags); + if (*dma_addr == DMA_ERROR_CODE) goto out_free; - } - - domain_flush_complete(domain); - - spin_unlock_irqrestore(&domain->lock, flags); return page_address(page); @@ -2781,7 +2740,6 @@ static void free_coherent(struct device *dev, size_t size, struct dma_attrs *attrs) { struct protection_domain *domain; - unsigned long flags; struct page *page; INC_STATS_COUNTER(cnt_free_coherent); @@ -2793,14 +2751,8 @@ static void free_coherent(struct device *dev, size_t size, if (IS_ERR(domain)) goto free_mem; - spin_lock_irqsave(&domain->lock, flags); - __unmap_single(domain->priv, dma_addr, size, DMA_BIDIRECTIONAL); - domain_flush_complete(domain); - - spin_unlock_irqrestore(&domain->lock, flags); - free_mem: if (!dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT)) __free_pages(page, get_order(size)); -- 2.20.1