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authorIan Campbell <ian.campbell@citrix.com>2008-12-16 12:17:31 -0800
committerIngo Molnar <mingo@elte.hu>2008-12-17 18:58:13 +0100
commitb81ea27b2329bf44b30c427800954f845896d476 (patch)
tree84bbfc80477c3561ee601c1c05dcc0917ced196b /lib/swiotlb.c
parente08e1f7adba522378e8d2ae941bf25443866136d (diff)
downloadlinux-b81ea27b2329bf44b30c427800954f845896d476.tar.gz
swiotlb: add arch hook to force mapping
Impact: generalize the sw-IOTLB range checks

Some architectures require special rules to determine whether a range
needs mapping or not.  This adds a weak function for architectures to
override.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'lib/swiotlb.c')
-rw-r--r--lib/swiotlb.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 3494263cdd9a..d8b09051c455 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -145,6 +145,11 @@ static void *swiotlb_bus_to_virt(dma_addr_t address)
 	return phys_to_virt(swiotlb_bus_to_phys(address));
 }
 
+int __weak swiotlb_arch_range_needs_mapping(void *ptr, size_t size)
+{
+	return 0;
+}
+
 /*
  * Statically reserve bounce buffer space and initialize bounce buffer data
  * structures for the software IO TLB used to implement the DMA API.
@@ -297,6 +302,11 @@ address_needs_mapping(struct device *hwdev, dma_addr_t addr, size_t size)
 	return !is_buffer_dma_capable(dma_get_mask(hwdev), addr, size);
 }
 
+static inline int range_needs_mapping(void *ptr, size_t size)
+{
+	return swiotlb_force || swiotlb_arch_range_needs_mapping(ptr, size);
+}
+
 static int is_swiotlb_buffer(char *addr)
 {
 	return addr >= io_tlb_start && addr < io_tlb_end;
@@ -585,7 +595,8 @@ swiotlb_map_single_attrs(struct device *hwdev, void *ptr, size_t size,
 	 * we can safely return the device addr and not worry about bounce
 	 * buffering it.
 	 */
-	if (!address_needs_mapping(hwdev, dev_addr, size) && !swiotlb_force)
+	if (!address_needs_mapping(hwdev, dev_addr, size) &&
+	    !range_needs_mapping(ptr, size))
 		return dev_addr;
 
 	/*
@@ -745,7 +756,7 @@ swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
 	for_each_sg(sgl, sg, nelems, i) {
 		addr = SG_ENT_VIRT_ADDRESS(sg);
 		dev_addr = swiotlb_virt_to_bus(addr);
-		if (swiotlb_force ||
+		if (range_needs_mapping(sg_virt(sg), sg->length) ||
 		    address_needs_mapping(hwdev, dev_addr, sg->length)) {
 			void *map = map_single(hwdev, addr, sg->length, dir);
 			if (!map) {