Add the functions, swiotlb_{alloc,free} to support the memory allocation from restricted DMA pool.
Signed-off-by: Claire Chang tientzu@chromium.org --- include/linux/swiotlb.h | 4 ++++ kernel/dma/swiotlb.c | 35 +++++++++++++++++++++++++++++++++-- 2 files changed, 37 insertions(+), 2 deletions(-)
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index 0c5a18d9cf89..e8cf49bd90c5 100644 --- a/include/linux/swiotlb.h +++ b/include/linux/swiotlb.h @@ -134,6 +134,10 @@ unsigned int swiotlb_max_segment(void); size_t swiotlb_max_mapping_size(struct device *dev); bool is_swiotlb_active(struct device *dev); void __init swiotlb_adjust_size(unsigned long size); +#ifdef CONFIG_DMA_RESTRICTED_POOL +struct page *swiotlb_alloc(struct device *dev, size_t size); +bool swiotlb_free(struct device *dev, struct page *page, size_t size); +#endif /* CONFIG_DMA_RESTRICTED_POOL */ #else #define swiotlb_force SWIOTLB_NO_FORCE static inline bool is_swiotlb_buffer(struct device *dev, phys_addr_t paddr) diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index c4fc2e444e7a..648bfdde4b0c 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -457,8 +457,9 @@ static int find_slots(struct device *dev, phys_addr_t orig_addr,
index = wrap = wrap_index(mem, ALIGN(mem->index, stride)); do { - if ((slot_addr(tbl_dma_addr, index) & iotlb_align_mask) != - (orig_addr & iotlb_align_mask)) { + if (orig_addr && + (slot_addr(tbl_dma_addr, index) & iotlb_align_mask) != + (orig_addr & iotlb_align_mask)) { index = wrap_index(mem, index + 1); continue; } @@ -704,6 +705,36 @@ late_initcall(swiotlb_create_default_debugfs); #endif
#ifdef CONFIG_DMA_RESTRICTED_POOL +struct page *swiotlb_alloc(struct device *dev, size_t size) +{ + struct io_tlb_mem *mem = dev->dma_io_tlb_mem; + phys_addr_t tlb_addr; + int index; + + if (!mem) + return NULL; + + index = find_slots(dev, 0, size); + if (index == -1) + return NULL; + + tlb_addr = slot_addr(mem->start, index); + + return pfn_to_page(PFN_DOWN(tlb_addr)); +} + +bool swiotlb_free(struct device *dev, struct page *page, size_t size) +{ + phys_addr_t tlb_addr = page_to_phys(page); + + if (!is_swiotlb_buffer(dev, tlb_addr)) + return false; + + release_slots(dev, tlb_addr); + + return true; +} + static int rmem_swiotlb_device_init(struct reserved_mem *rmem, struct device *dev) {