From: Joerg Roedel <[email protected]> First search for a non-contended aperture with trylock before spinning.
Signed-off-by: Joerg Roedel <[email protected]> --- drivers/iommu/amd_iommu.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 84c7da1..eed355c 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -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); - spin_lock_irqsave(&range->bitmap_lock, flags); + 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; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
