Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit b81ea27b authored by Ian Campbell's avatar Ian Campbell Committed by Ingo Molnar
Browse files

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: default avatarIan Campbell <ian.campbell@citrix.com>
Signed-off-by: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent e08e1f7a

include/linux/swiotlb.h

+2 −0
Original line number Diff line number Diff line
@@ -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);

lib/swiotlb.c

+13 −2
Original line number Diff line number Diff line
@@ -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) {