swiotlb: add is_swiotlb_buffer helper function

This adds is_swiotlb_buffer() helper function to see whether a buffer
belongs to the swiotlb buffer or not.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 9 insertions, 5 deletions

diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index bf61c73a341..b5f5d113304 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -283,6 +283,11 @@ address_needs_mapping(struct device *hwdev, dma_addr_t addr)
         return (addr & ~mask) != 0;
 }
 
+static int is_swiotlb_buffer(char *addr)
+{
+        return addr >= io_tlb_start && addr < io_tlb_end;
+}
+
 /*
  * Allocates bounce buffer and returns its kernel virtual address.
  */
@@ -508,8 +513,7 @@ swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
                       dma_addr_t dma_handle)
 {
         WARN_ON(irqs_disabled());
-        if (!(vaddr >= (void *)io_tlb_start
-                    && vaddr < (void *)io_tlb_end))
+        if (!is_swiotlb_buffer(vaddr))
                 free_pages((unsigned long) vaddr, get_order(size));
         else
                 /* DMA_TO_DEVICE to avoid memcpy in unmap_single */
@@ -602,7 +606,7 @@ swiotlb_unmap_single_attrs(struct device *hwdev, dma_addr_t dev_addr,
         char *dma_addr = bus_to_virt(dev_addr);
 
         BUG_ON(dir == DMA_NONE);
-        if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end)
+        if (is_swiotlb_buffer(dma_addr))
                 unmap_single(hwdev, dma_addr, size, dir);
         else if (dir == DMA_FROM_DEVICE)
                 dma_mark_clean(dma_addr, size);
@@ -632,7 +636,7 @@ swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr,
         char *dma_addr = bus_to_virt(dev_addr);
 
         BUG_ON(dir == DMA_NONE);
-        if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end)
+        if (is_swiotlb_buffer(dma_addr))
                 sync_single(hwdev, dma_addr, size, dir, target);
         else if (dir == DMA_FROM_DEVICE)
                 dma_mark_clean(dma_addr, size);
@@ -663,7 +667,7 @@ swiotlb_sync_single_range(struct device *hwdev, dma_addr_t dev_addr,
         char *dma_addr = bus_to_virt(dev_addr) + offset;
 
         BUG_ON(dir == DMA_NONE);
-        if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end)
+        if (is_swiotlb_buffer(dma_addr))
                 sync_single(hwdev, dma_addr, size, dir, target);
         else if (dir == DMA_FROM_DEVICE)
                 dma_mark_clean(dma_addr, size);