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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
parente08e1f7adba522378e8d2ae941bf25443866136d (diff)
downloadop-kernel-dev-b81ea27b2329bf44b30c427800954f845896d476.zip
op-kernel-dev-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>
-rw-r--r--include/linux/swiotlb.h2
-rw-r--r--lib/swiotlb.c15
2 files changed, 15 insertions, 2 deletions
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 694f183..325af1d 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -30,6 +30,8 @@ extern void *swiotlb_alloc(unsigned order, unsigned long nslabs);
extern dma_addr_t swiotlb_phys_to_bus(phys_addr_t address);
extern phys_addr_t swiotlb_bus_to_phys(dma_addr_t address);
+extern int swiotlb_arch_range_needs_mapping(void *ptr, size_t size);
+
extern void
*swiotlb_alloc_coherent(struct device *hwdev, size_t size,
dma_addr_t *dma_handle, gfp_t flags);
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 3494263..d8b0905 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) {
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