iommu/amd: Relax locking in dma_ops path
Remove the long holding times of the domain->lock and rely
on the bitmap_lock instead.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 11ee885..e98a466 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -1466,8 +1466,10 @@
}
}
+ spin_lock_irqsave(&dma_dom->domain.lock, flags);
+
/* First take the bitmap_lock and then publish the range */
- spin_lock_irqsave(&range->bitmap_lock, flags);
+ spin_lock(&range->bitmap_lock);
old_size = dma_dom->aperture_size;
dma_dom->aperture[index] = range;
@@ -1518,7 +1520,9 @@
update_domain(&dma_dom->domain);
- spin_unlock_irqrestore(&range->bitmap_lock, flags);
+ spin_unlock(&range->bitmap_lock);
+
+ spin_unlock_irqrestore(&dma_dom->domain.lock, flags);
return 0;
@@ -2562,11 +2566,9 @@
enum dma_data_direction dir,
struct dma_attrs *attrs)
{
- unsigned long flags;
- struct protection_domain *domain;
- dma_addr_t addr;
- u64 dma_mask;
phys_addr_t paddr = page_to_phys(page) + offset;
+ struct protection_domain *domain;
+ u64 dma_mask;
INC_STATS_COUNTER(cnt_map_single);
@@ -2578,19 +2580,8 @@
dma_mask = *dev->dma_mask;
- spin_lock_irqsave(&domain->lock, flags);
-
- addr = __map_single(dev, domain->priv, paddr, size, dir, false,
+ return __map_single(dev, domain->priv, paddr, size, dir, false,
dma_mask);
- if (addr == DMA_ERROR_CODE)
- goto out;
-
- domain_flush_complete(domain);
-
-out:
- spin_unlock_irqrestore(&domain->lock, flags);
-
- return addr;
}
/*
@@ -2599,7 +2590,6 @@
static void unmap_page(struct device *dev, dma_addr_t dma_addr, size_t size,
enum dma_data_direction dir, struct dma_attrs *attrs)
{
- unsigned long flags;
struct protection_domain *domain;
INC_STATS_COUNTER(cnt_unmap_single);
@@ -2608,13 +2598,7 @@
if (IS_ERR(domain))
return;
- spin_lock_irqsave(&domain->lock, flags);
-
__unmap_single(domain->priv, dma_addr, size, dir);
-
- domain_flush_complete(domain);
-
- spin_unlock_irqrestore(&domain->lock, flags);
}
/*
@@ -2625,7 +2609,6 @@
int nelems, enum dma_data_direction dir,
struct dma_attrs *attrs)
{
- unsigned long flags;
struct protection_domain *domain;
int i;
struct scatterlist *s;
@@ -2641,8 +2624,6 @@
dma_mask = *dev->dma_mask;
- spin_lock_irqsave(&domain->lock, flags);
-
for_each_sg(sglist, s, nelems, i) {
paddr = sg_phys(s);
@@ -2657,12 +2638,8 @@
goto unmap;
}
- domain_flush_complete(domain);
-
-out:
- spin_unlock_irqrestore(&domain->lock, flags);
-
return mapped_elems;
+
unmap:
for_each_sg(sglist, s, mapped_elems, i) {
if (s->dma_address)
@@ -2671,9 +2648,7 @@
s->dma_address = s->dma_length = 0;
}
- mapped_elems = 0;
-
- goto out;
+ return 0;
}
/*
@@ -2684,7 +2659,6 @@
int nelems, enum dma_data_direction dir,
struct dma_attrs *attrs)
{
- unsigned long flags;
struct protection_domain *domain;
struct scatterlist *s;
int i;
@@ -2695,17 +2669,11 @@
if (IS_ERR(domain))
return;
- spin_lock_irqsave(&domain->lock, flags);
-
for_each_sg(sglist, s, nelems, i) {
__unmap_single(domain->priv, s->dma_address,
s->dma_length, dir);
s->dma_address = s->dma_length = 0;
}
-
- domain_flush_complete(domain);
-
- spin_unlock_irqrestore(&domain->lock, flags);
}
/*
@@ -2717,7 +2685,6 @@
{
u64 dma_mask = dev->coherent_dma_mask;
struct protection_domain *domain;
- unsigned long flags;
struct page *page;
INC_STATS_COUNTER(cnt_alloc_coherent);
@@ -2749,19 +2716,11 @@
if (!dma_mask)
dma_mask = *dev->dma_mask;
- spin_lock_irqsave(&domain->lock, flags);
-
*dma_addr = __map_single(dev, domain->priv, page_to_phys(page),
size, DMA_BIDIRECTIONAL, true, dma_mask);
- if (*dma_addr == DMA_ERROR_CODE) {
- spin_unlock_irqrestore(&domain->lock, flags);
+ if (*dma_addr == DMA_ERROR_CODE)
goto out_free;
- }
-
- domain_flush_complete(domain);
-
- spin_unlock_irqrestore(&domain->lock, flags);
return page_address(page);
@@ -2781,7 +2740,6 @@
struct dma_attrs *attrs)
{
struct protection_domain *domain;
- unsigned long flags;
struct page *page;
INC_STATS_COUNTER(cnt_free_coherent);
@@ -2793,14 +2751,8 @@
if (IS_ERR(domain))
goto free_mem;
- spin_lock_irqsave(&domain->lock, flags);
-
__unmap_single(domain->priv, dma_addr, size, DMA_BIDIRECTIONAL);
- domain_flush_complete(domain);
-
- spin_unlock_irqrestore(&domain->lock, flags);
-
free_mem:
if (!dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT))
__free_pages(page, get_order(size));