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Commit 7b5e25b8 authored by Joerg Roedel's avatar Joerg Roedel
Browse files

iommu/amd: Use trylock to aquire bitmap_lock 



First search for a non-contended aperture with trylock
before spinning.

Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 5f6bed50

drivers/iommu/amd_iommu.c

+17 −3
Original line number Diff line number Diff line
@@ -1542,7 +1542,8 @@ static dma_addr_t dma_ops_aperture_alloc(struct dma_ops_domain *dom, 
					 unsigned long pages,

					 unsigned long dma_mask,

					 unsigned long boundary_size,

					 unsigned long align_mask)

					 unsigned long align_mask,

					 bool trylock)

{

	unsigned long offset, limit, flags;

	dma_addr_t address;
@@ -1552,7 +1553,13 @@ static dma_addr_t dma_ops_aperture_alloc(struct dma_ops_domain *dom, 
	limit  = iommu_device_max_index(APERTURE_RANGE_PAGES, offset,

					dma_mask >> PAGE_SHIFT);



	if (trylock) {

		if (!spin_trylock_irqsave(&range->bitmap_lock, flags))

			return -1;

	} else {

		spin_lock_irqsave(&range->bitmap_lock, flags);

	}



	address = iommu_area_alloc(range->bitmap, limit, range->next_bit,

				   pages, offset, boundary_size, align_mask);

	if (address == -1) {
@@ -1584,12 +1591,14 @@ static unsigned long dma_ops_area_alloc(struct device *dev, 
{

	unsigned long boundary_size, mask;

	unsigned long address = -1;

	bool first = true;

	u32 start, i;



	preempt_disable();



	mask = dma_get_seg_boundary(dev);



again:

	start = this_cpu_read(*dom->next_index);



	/* Sanity check - is it really necessary? */
@@ -1614,7 +1623,7 @@ static unsigned long dma_ops_area_alloc(struct device *dev, 


		address = dma_ops_aperture_alloc(dom, range, pages,

						 dma_mask, boundary_size,

						 align_mask);

						 align_mask, first);

		if (address != -1) {

			address = range->offset + (address << PAGE_SHIFT);

			this_cpu_write(*dom->next_index, index);
@@ -1622,6 +1631,11 @@ static unsigned long dma_ops_area_alloc(struct device *dev, 
		}

	}



	if (address == -1 && first) {

		first = false;

		goto again;

	}



	preempt_enable();



	return address;