swiotlb: allow architectures to override phys<->bus<->phys conversions

Impact: generalize phys<->bus<->phys conversions in the swiotlb code

Architectures may need to override these conversions. Implement a
__weak hook point containing the default implementation.

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, 3 insertions, 0 deletions

diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 58b996a642f9..694f1839cbc0 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -27,6 +27,9 @@ swiotlb_init(void);
 extern void *swiotlb_alloc_boot(size_t bytes, unsigned long nslabs);
 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 void
 *swiotlb_alloc_coherent(struct device *hwdev, size_t size,
                         dma_addr_t *dma_handle, gfp_t flags);