Commit 7374153d authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

swiotlb: provide swiotlb_init variants that remap the buffer 



To shared more code between swiotlb and xen-swiotlb, offer a
swiotlb_init_remap interface and add a remap callback to
swiotlb_init_late that will allow Xen to remap the buffer without
duplicating much of the logic.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
parent 74251953

arch/x86/pci/sta2x11-fixup.c

+1 −1
Original line number Diff line number Diff line
@@ -57,7 +57,7 @@ static void sta2x11_new_instance(struct pci_dev *pdev) 
		int size = STA2X11_SWIOTLB_SIZE;

		/* First instance: register your own swiotlb area */

		dev_info(&pdev->dev, "Using SWIOTLB (size %i)\n", size);

		if (swiotlb_init_late(size, GFP_DMA))

		if (swiotlb_init_late(size, GFP_DMA, NULL))

			dev_emerg(&pdev->dev, "init swiotlb failed\n");

	}

	list_add(&instance->list, &sta2x11_instance_list);

include/linux/swiotlb.h

+4 −1
Original line number Diff line number Diff line
@@ -36,8 +36,11 @@ struct scatterlist; 


int swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, unsigned int flags);

unsigned long swiotlb_size_or_default(void);

void __init swiotlb_init_remap(bool addressing_limit, unsigned int flags,

	int (*remap)(void *tlb, unsigned long nslabs));

int swiotlb_init_late(size_t size, gfp_t gfp_mask,

	int (*remap)(void *tlb, unsigned long nslabs));

extern int swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs);

int swiotlb_init_late(size_t size, gfp_t gfp_mask);

extern void __init swiotlb_update_mem_attributes(void);



phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, phys_addr_t phys,

kernel/dma/swiotlb.c

+33 −3
Original line number Diff line number Diff line
@@ -256,9 +256,11 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, 
 * Statically reserve bounce buffer space and initialize bounce buffer data

 * structures for the software IO TLB used to implement the DMA API.

 */

void __init swiotlb_init(bool addressing_limit, unsigned int flags)

void __init swiotlb_init_remap(bool addressing_limit, unsigned int flags,

		int (*remap)(void *tlb, unsigned long nslabs))

{

	size_t bytes = PAGE_ALIGN(default_nslabs << IO_TLB_SHIFT);

	unsigned long nslabs = default_nslabs;

	size_t bytes;

	void *tlb;



	if (!addressing_limit && !swiotlb_force_bounce)
@@ -271,12 +273,23 @@ void __init swiotlb_init(bool addressing_limit, unsigned int flags) 
	 * allow to pick a location everywhere for hypervisors with guest

	 * memory encryption.

	 */

retry:

	bytes = PAGE_ALIGN(default_nslabs << IO_TLB_SHIFT);

	if (flags & SWIOTLB_ANY)

		tlb = memblock_alloc(bytes, PAGE_SIZE);

	else

		tlb = memblock_alloc_low(bytes, PAGE_SIZE);

	if (!tlb)

		goto fail;

	if (remap && remap(tlb, nslabs) < 0) {

		memblock_free(tlb, PAGE_ALIGN(bytes));



		nslabs = ALIGN(nslabs >> 1, IO_TLB_SEGSIZE);

		if (nslabs < IO_TLB_MIN_SLABS)

			panic("%s: Failed to remap %zu bytes\n",

			      __func__, bytes);

		goto retry;

	}

	if (swiotlb_init_with_tbl(tlb, default_nslabs, flags))

		goto fail_free_mem;

	return;
@@ -287,12 +300,18 @@ void __init swiotlb_init(bool addressing_limit, unsigned int flags) 
	pr_warn("Cannot allocate buffer");

}



void __init swiotlb_init(bool addressing_limit, unsigned int flags)

{

	return swiotlb_init_remap(addressing_limit, flags, NULL);

}



/*

 * Systems with larger DMA zones (those that don't support ISA) can

 * initialize the swiotlb later using the slab allocator if needed.

 * This should be just like above, but with some error catching.

 */

int swiotlb_init_late(size_t size, gfp_t gfp_mask)

int swiotlb_init_late(size_t size, gfp_t gfp_mask,

		int (*remap)(void *tlb, unsigned long nslabs))

{

	unsigned long nslabs = ALIGN(size >> IO_TLB_SHIFT, IO_TLB_SEGSIZE);

	unsigned long bytes;
@@ -303,6 +322,7 @@ int swiotlb_init_late(size_t size, gfp_t gfp_mask) 
	if (swiotlb_force_disable)

		return 0;



retry:

	order = get_order(nslabs << IO_TLB_SHIFT);

	nslabs = SLABS_PER_PAGE << order;

	bytes = nslabs << IO_TLB_SHIFT;
@@ -323,6 +343,16 @@ int swiotlb_init_late(size_t size, gfp_t gfp_mask) 
			(PAGE_SIZE << order) >> 20);

		nslabs = SLABS_PER_PAGE << order;

	}

	if (remap)

		rc = remap(vstart, nslabs);

	if (rc) {

		free_pages((unsigned long)vstart, order);



		nslabs = ALIGN(nslabs >> 1, IO_TLB_SEGSIZE);

		if (nslabs < IO_TLB_MIN_SLABS)

			return rc;

		goto retry;

	}

	rc = swiotlb_late_init_with_tbl(vstart, nslabs);

	if (rc)

		free_pages((unsigned long)vstart, order);