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>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 694f1839cbc0..325af1de0351 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);