[PATCH 09/22] swiotlb: refactor coherent buffer freeing
From: Christoph Hellwig <hch@lst.de>
Date: 2018-01-10 08:10:11
Also in:
linux-arch, linux-arm-kernel, linux-iommu, linux-mips, lkml
Subsystem:
library code, the rest · Maintainers:
Andrew Morton, Linus Torvalds
Factor out a new swiotlb_free_buffer helper that checks if an address is allocated from the swiotlb bounce buffer, and if yes frees it. This allows to simplify the swiotlb_free implemenation that uses dma_direct_free to free the non-bounce buffer allocations. Signed-off-by: Christoph Hellwig <hch@lst.de> --- lib/swiotlb.c | 35 +++++++++++++++++++++-------------- 1 file changed, 21 insertions(+), 14 deletions(-)
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 539fd1099ba9..1a147f1354a1 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c@@ -780,22 +780,31 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size, } EXPORT_SYMBOL(swiotlb_alloc_coherent); +static bool swiotlb_free_buffer(struct device *dev, size_t size, + dma_addr_t dma_addr) +{ + phys_addr_t phys_addr = dma_to_phys(dev, dma_addr); + + WARN_ON_ONCE(irqs_disabled()); + + if (!is_swiotlb_buffer(phys_addr)) + return false; + + /* + * DMA_TO_DEVICE to avoid memcpy in swiotlb_tbl_unmap_single. + * DMA_ATTR_SKIP_CPU_SYNC is optional. + */ + swiotlb_tbl_unmap_single(dev, phys_addr, size, DMA_TO_DEVICE, + DMA_ATTR_SKIP_CPU_SYNC); + return true; +} + void swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr, dma_addr_t dev_addr) { - phys_addr_t paddr = dma_to_phys(hwdev, dev_addr); - - WARN_ON(irqs_disabled()); - if (!is_swiotlb_buffer(paddr)) + if (!swiotlb_free_buffer(hwdev, size, dev_addr)) free_pages((unsigned long)vaddr, get_order(size)); - else - /* - * DMA_TO_DEVICE to avoid memcpy in swiotlb_tbl_unmap_single. - * DMA_ATTR_SKIP_CPU_SYNC is optional. - */ - swiotlb_tbl_unmap_single(hwdev, paddr, size, DMA_TO_DEVICE, - DMA_ATTR_SKIP_CPU_SYNC); } EXPORT_SYMBOL(swiotlb_free_coherent);
@@ -1110,9 +1119,7 @@ void *swiotlb_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, void swiotlb_free(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_addr, unsigned long attrs) { - if (is_swiotlb_buffer(dma_to_phys(dev, dma_addr))) - swiotlb_free_coherent(dev, size, vaddr, dma_addr); - else + if (!swiotlb_free_buffer(dev, size, dma_addr)) dma_direct_free(dev, size, vaddr, dma_addr, attrs); }
--
2.14.2