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 | 15 +++++++++++++++ kernel/dma/swiotlb.c | 35 +++++++++++++++++++++++++++++++++-- 2 files changed, 48 insertions(+), 2 deletions(-)
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index 8200c100fe10..d3374497a4f8 100644 --- a/include/linux/swiotlb.h +++ b/include/linux/swiotlb.h @@ -162,4 +162,19 @@ static inline void swiotlb_adjust_size(unsigned long size) extern void swiotlb_print_info(void); extern void swiotlb_set_max_segment(unsigned int);
+#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); +#else +static inline struct page *swiotlb_alloc(struct device *dev, size_t size) +{ + return NULL; +} +static inline bool swiotlb_free(struct device *dev, struct page *page, + size_t size) +{ + return false; +} +#endif /* CONFIG_DMA_RESTRICTED_POOL */ + #endif /* __LINUX_SWIOTLB_H */ diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index a6562573f090..0a19858da5b8 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -461,8 +461,9 @@ 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; } @@ -702,6 +703,36 @@ 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) {