Commit cbce9952 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Konrad Rzeszutek Wilk
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xen-swiotlb: remove xen_io_tlb_start and xen_io_tlb_nslabs 



The xen_io_tlb_start and xen_io_tlb_nslabs variables are now only used in
xen_swiotlb_init, so replace them with local variables.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent 4035b43d

drivers/xen/swiotlb-xen.c

+25 −32
Original line number Diff line number Diff line
@@ -40,14 +40,7 @@ 


#include <trace/events/swiotlb.h>

#define MAX_DMA_BITS 32

/*

 * Used to do a quick range check in swiotlb_tbl_unmap_single and

 * swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by this

 * API.

 */



static char *xen_io_tlb_start;

static unsigned long xen_io_tlb_nslabs;

/*

 * Quick lookup value of the bus address of the IOTLB.

 */
@@ -169,75 +162,75 @@ int __ref xen_swiotlb_init(int verbose, bool early) 
	int rc = -ENOMEM;

	enum xen_swiotlb_err m_ret = XEN_SWIOTLB_UNKNOWN;

	unsigned int repeat = 3;

	char *start;

	unsigned long nslabs;



	xen_io_tlb_nslabs = swiotlb_nr_tbl();

	nslabs = swiotlb_nr_tbl();

retry:

	if (!xen_io_tlb_nslabs)

		xen_io_tlb_nslabs = DEFAULT_NSLABS;

	bytes = xen_io_tlb_nslabs << IO_TLB_SHIFT;

	if (!nslabs)

		nslabs = DEFAULT_NSLABS;

	bytes = nslabs << IO_TLB_SHIFT;

	order = get_order(bytes);



	/*

	 * IO TLB memory already allocated. Just use it.

	 */

	if (io_tlb_start != 0) {

		xen_io_tlb_start = phys_to_virt(io_tlb_start);

	if (io_tlb_start != 0)

		goto end;

	}



	/*

	 * Get IO TLB memory from any location.

	 */

	if (early) {

		xen_io_tlb_start = memblock_alloc(PAGE_ALIGN(bytes),

		start = memblock_alloc(PAGE_ALIGN(bytes),

						  PAGE_SIZE);

		if (!xen_io_tlb_start)

		if (!start)

			panic("%s: Failed to allocate %lu bytes align=0x%lx\n",

			      __func__, PAGE_ALIGN(bytes), PAGE_SIZE);

	} else {

#define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT))

#define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT)

		while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {

			xen_io_tlb_start = (void *)xen_get_swiotlb_free_pages(order);

			if (xen_io_tlb_start)

			start = (void *)xen_get_swiotlb_free_pages(order);

			if (start)

				break;

			order--;

		}

		if (order != get_order(bytes)) {

			pr_warn("Warning: only able to allocate %ld MB for software IO TLB\n",

				(PAGE_SIZE << order) >> 20);

			xen_io_tlb_nslabs = SLABS_PER_PAGE << order;

			bytes = xen_io_tlb_nslabs << IO_TLB_SHIFT;

			nslabs = SLABS_PER_PAGE << order;

			bytes = nslabs << IO_TLB_SHIFT;

		}

	}

	if (!xen_io_tlb_start) {

	if (!start) {

		m_ret = XEN_SWIOTLB_ENOMEM;

		goto error;

	}

	/*

	 * And replace that memory with pages under 4GB.

	 */

	rc = xen_swiotlb_fixup(xen_io_tlb_start,

	rc = xen_swiotlb_fixup(start,

			       bytes,

			       xen_io_tlb_nslabs);

			       nslabs);

	if (rc) {

		if (early)

			memblock_free(__pa(xen_io_tlb_start),

			memblock_free(__pa(start),

				      PAGE_ALIGN(bytes));

		else {

			free_pages((unsigned long)xen_io_tlb_start, order);

			xen_io_tlb_start = NULL;

			free_pages((unsigned long)start, order);

			start = NULL;

		}

		m_ret = XEN_SWIOTLB_EFIXUP;

		goto error;

	}

	if (early) {

		if (swiotlb_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs,

		if (swiotlb_init_with_tbl(start, nslabs,

			 verbose))

			panic("Cannot allocate SWIOTLB buffer");

		rc = 0;

	} else

		rc = swiotlb_late_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs);

		rc = swiotlb_late_init_with_tbl(start, nslabs);



end:

	if (!rc)
@@ -246,17 +239,17 @@ int __ref xen_swiotlb_init(int verbose, bool early) 
	return rc;

error:

	if (repeat--) {

		xen_io_tlb_nslabs = max(1024UL, /* Min is 2MB */

					(xen_io_tlb_nslabs >> 1));

		nslabs = max(1024UL, /* Min is 2MB */

					(nslabs >> 1));

		pr_info("Lowering to %luMB\n",

			(xen_io_tlb_nslabs << IO_TLB_SHIFT) >> 20);

			(nslabs << IO_TLB_SHIFT) >> 20);

		goto retry;

	}

	pr_err("%s (rc:%d)\n", xen_swiotlb_error(m_ret), rc);

	if (early)

		panic("%s (rc:%d)", xen_swiotlb_error(m_ret), rc);

	else

		free_pages((unsigned long)xen_io_tlb_start, order);

		free_pages((unsigned long)start, order);

	return rc;

}