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| author | Ian Campbell <ian.campbell@citrix.com> | 2008-12-16 12:17:31 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-12-17 18:58:13 +0100 |
| commit | b81ea27b2329bf44b30c427800954f845896d476 (patch) | |
| tree | 84bbfc80477c3561ee601c1c05dcc0917ced196b | |
| parent | e08e1f7adba522378e8d2ae941bf25443866136d (diff) | |
| download | op-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.h | 2 | ||||
| -rw-r--r-- | lib/swiotlb.c | 15 |
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) { |
