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Commit e08e1f7a authored by Ian Campbell's avatar Ian Campbell Committed by Ingo Molnar
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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: 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 a5ddde4a

include/linux/swiotlb.h

+3 −0
Original line number Diff line number Diff line
@@ -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);

lib/swiotlb.c

+36 −16
Original line number Diff line number Diff line
@@ -125,6 +125,26 @@ void * __weak swiotlb_alloc(unsigned order, unsigned long nslabs) 
	return (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN, order);

}



dma_addr_t __weak swiotlb_phys_to_bus(phys_addr_t paddr)

{

	return paddr;

}



phys_addr_t __weak swiotlb_bus_to_phys(dma_addr_t baddr)

{

	return baddr;

}



static dma_addr_t swiotlb_virt_to_bus(volatile void *address)

{

	return swiotlb_phys_to_bus(virt_to_phys(address));

}



static void *swiotlb_bus_to_virt(dma_addr_t address)

{

	return phys_to_virt(swiotlb_bus_to_phys(address));

}



/*

 * Statically reserve bounce buffer space and initialize bounce buffer data

 * structures for the software IO TLB used to implement the DMA API.
@@ -168,7 +188,7 @@ swiotlb_init_with_default_size(size_t default_size) 
		panic("Cannot allocate SWIOTLB overflow buffer!\n");



	printk(KERN_INFO "Placing software IO TLB between 0x%lx - 0x%lx\n",

	       virt_to_bus(io_tlb_start), virt_to_bus(io_tlb_end));

	       swiotlb_virt_to_bus(io_tlb_start), swiotlb_virt_to_bus(io_tlb_end));

}



void __init
@@ -250,7 +270,7 @@ swiotlb_late_init_with_default_size(size_t default_size) 


	printk(KERN_INFO "Placing %luMB software IO TLB between 0x%lx - "

	       "0x%lx\n", bytes >> 20,

	       virt_to_bus(io_tlb_start), virt_to_bus(io_tlb_end));

	       swiotlb_virt_to_bus(io_tlb_start), swiotlb_virt_to_bus(io_tlb_end));



	return 0;
@@ -298,7 +318,7 @@ map_single(struct device *hwdev, char *buffer, size_t size, int dir) 
	unsigned long max_slots;



	mask = dma_get_seg_boundary(hwdev);

	start_dma_addr = virt_to_bus(io_tlb_start) & mask;

	start_dma_addr = swiotlb_virt_to_bus(io_tlb_start) & mask;



	offset_slots = ALIGN(start_dma_addr, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
@@ -475,7 +495,7 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size, 
		dma_mask = hwdev->coherent_dma_mask;



	ret = (void *)__get_free_pages(flags, order);

	if (ret && !is_buffer_dma_capable(dma_mask, virt_to_bus(ret), size)) {

	if (ret && !is_buffer_dma_capable(dma_mask, swiotlb_virt_to_bus(ret), size)) {

		/*

		 * The allocated memory isn't reachable by the device.

		 * Fall back on swiotlb_map_single().
@@ -496,7 +516,7 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size, 
	}



	memset(ret, 0, size);

	dev_addr = virt_to_bus(ret);

	dev_addr = swiotlb_virt_to_bus(ret);



	/* Confirm address can be DMA'd by device */

	if (!is_buffer_dma_capable(dma_mask, dev_addr, size)) {
@@ -556,7 +576,7 @@ dma_addr_t 
swiotlb_map_single_attrs(struct device *hwdev, void *ptr, size_t size,

			 int dir, struct dma_attrs *attrs)

{

	dma_addr_t dev_addr = virt_to_bus(ptr);

	dma_addr_t dev_addr = swiotlb_virt_to_bus(ptr);

	void *map;



	BUG_ON(dir == DMA_NONE);
@@ -577,7 +597,7 @@ swiotlb_map_single_attrs(struct device *hwdev, void *ptr, size_t size, 
		map = io_tlb_overflow_buffer;

	}



	dev_addr = virt_to_bus(map);

	dev_addr = swiotlb_virt_to_bus(map);



	/*

	 * Ensure that the address returned is DMA'ble
@@ -607,7 +627,7 @@ void 
swiotlb_unmap_single_attrs(struct device *hwdev, dma_addr_t dev_addr,

			   size_t size, int dir, struct dma_attrs *attrs)

{

	char *dma_addr = bus_to_virt(dev_addr);

	char *dma_addr = swiotlb_bus_to_virt(dev_addr);



	BUG_ON(dir == DMA_NONE);

	if (is_swiotlb_buffer(dma_addr))
@@ -637,7 +657,7 @@ static void 
swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr,

		    size_t size, int dir, int target)

{

	char *dma_addr = bus_to_virt(dev_addr);

	char *dma_addr = swiotlb_bus_to_virt(dev_addr);



	BUG_ON(dir == DMA_NONE);

	if (is_swiotlb_buffer(dma_addr))
@@ -668,7 +688,7 @@ swiotlb_sync_single_range(struct device *hwdev, dma_addr_t dev_addr, 
			  unsigned long offset, size_t size,

			  int dir, int target)

{

	char *dma_addr = bus_to_virt(dev_addr) + offset;

	char *dma_addr = swiotlb_bus_to_virt(dev_addr) + offset;



	BUG_ON(dir == DMA_NONE);

	if (is_swiotlb_buffer(dma_addr))
@@ -724,7 +744,7 @@ 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 = virt_to_bus(addr);

		dev_addr = swiotlb_virt_to_bus(addr);

		if (swiotlb_force ||

		    address_needs_mapping(hwdev, dev_addr, sg->length)) {

			void *map = map_single(hwdev, addr, sg->length, dir);
@@ -737,7 +757,7 @@ swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems, 
				sgl[0].dma_length = 0;

				return 0;

			}

			sg->dma_address = virt_to_bus(map);

			sg->dma_address = swiotlb_virt_to_bus(map);

		} else

			sg->dma_address = dev_addr;

		sg->dma_length = sg->length;
@@ -768,7 +788,7 @@ swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl, 


	for_each_sg(sgl, sg, nelems, i) {

		if (sg->dma_address != SG_ENT_PHYS_ADDRESS(sg))

			unmap_single(hwdev, bus_to_virt(sg->dma_address),

			unmap_single(hwdev, swiotlb_bus_to_virt(sg->dma_address),

				     sg->dma_length, dir);

		else if (dir == DMA_FROM_DEVICE)

			dma_mark_clean(SG_ENT_VIRT_ADDRESS(sg), sg->dma_length);
@@ -801,7 +821,7 @@ swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl, 


	for_each_sg(sgl, sg, nelems, i) {

		if (sg->dma_address != SG_ENT_PHYS_ADDRESS(sg))

			sync_single(hwdev, bus_to_virt(sg->dma_address),

			sync_single(hwdev, swiotlb_bus_to_virt(sg->dma_address),

				    sg->dma_length, dir, target);

		else if (dir == DMA_FROM_DEVICE)

			dma_mark_clean(SG_ENT_VIRT_ADDRESS(sg), sg->dma_length);
@@ -825,7 +845,7 @@ swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg, 
int

swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr)

{

	return (dma_addr == virt_to_bus(io_tlb_overflow_buffer));

	return (dma_addr == swiotlb_virt_to_bus(io_tlb_overflow_buffer));

}



/*
@@ -837,7 +857,7 @@ swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr) 
int

swiotlb_dma_supported(struct device *hwdev, u64 mask)

{

	return virt_to_bus(io_tlb_end - 1) <= mask;

	return swiotlb_virt_to_bus(io_tlb_end - 1) <= mask;

}



EXPORT_SYMBOL(swiotlb_map_single);