iommu/amd: Optimize map_sg and unmap_sg
Optimize these functions so that they need only one call
into the address alloctor. This also saves a couple of
io-tlb flushes in the unmap_sg path.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 281cacb..acad37c 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -2396,50 +2396,110 @@
__unmap_single(domain->priv, dma_addr, size, dir);
}
+static int sg_num_pages(struct device *dev,
+ struct scatterlist *sglist,
+ int nelems)
+{
+ unsigned long mask, boundary_size;
+ struct scatterlist *s;
+ int i, npages = 0;
+
+ mask = dma_get_seg_boundary(dev);
+ boundary_size = mask + 1 ? ALIGN(mask + 1, PAGE_SIZE) >> PAGE_SHIFT :
+ 1UL << (BITS_PER_LONG - PAGE_SHIFT);
+
+ for_each_sg(sglist, s, nelems, i) {
+ int p, n;
+
+ s->dma_address = npages << PAGE_SHIFT;
+ p = npages % boundary_size;
+ n = iommu_num_pages(sg_phys(s), s->length, PAGE_SIZE);
+ if (p + n > boundary_size)
+ npages += boundary_size - p;
+ npages += n;
+ }
+
+ return npages;
+}
+
/*
* The exported map_sg function for dma_ops (handles scatter-gather
* lists).
*/
static int map_sg(struct device *dev, struct scatterlist *sglist,
- int nelems, enum dma_data_direction dir,
+ int nelems, enum dma_data_direction direction,
struct dma_attrs *attrs)
{
+ int mapped_pages = 0, npages = 0, prot = 0, i;
struct protection_domain *domain;
- int i;
+ struct dma_ops_domain *dma_dom;
struct scatterlist *s;
- phys_addr_t paddr;
- int mapped_elems = 0;
+ unsigned long address;
u64 dma_mask;
domain = get_domain(dev);
if (IS_ERR(domain))
return 0;
+ dma_dom = domain->priv;
dma_mask = *dev->dma_mask;
+ npages = sg_num_pages(dev, sglist, nelems);
+
+ address = dma_ops_alloc_iova(dev, dma_dom, npages, dma_mask);
+ if (address == DMA_ERROR_CODE)
+ goto out_err;
+
+ prot = dir2prot(direction);
+
+ /* Map all sg entries */
for_each_sg(sglist, s, nelems, i) {
- paddr = sg_phys(s);
+ int j, pages = iommu_num_pages(sg_phys(s), s->length, PAGE_SIZE);
- s->dma_address = __map_single(dev, domain->priv,
- paddr, s->length, dir, dma_mask);
+ for (j = 0; j < pages; ++j) {
+ unsigned long bus_addr, phys_addr;
+ int ret;
- if (s->dma_address) {
- s->dma_length = s->length;
- mapped_elems++;
- } else
- goto unmap;
+ bus_addr = address + s->dma_address + (j << PAGE_SHIFT);
+ phys_addr = (sg_phys(s) & PAGE_MASK) + (j << PAGE_SHIFT);
+ ret = iommu_map_page(domain, bus_addr, phys_addr, PAGE_SIZE, prot, GFP_ATOMIC);
+ if (ret)
+ goto out_unmap;
+
+ mapped_pages += 1;
+ }
}
- return mapped_elems;
-
-unmap:
- for_each_sg(sglist, s, mapped_elems, i) {
- if (s->dma_address)
- __unmap_single(domain->priv, s->dma_address,
- s->dma_length, dir);
- s->dma_address = s->dma_length = 0;
+ /* Everything is mapped - write the right values into s->dma_address */
+ for_each_sg(sglist, s, nelems, i) {
+ s->dma_address += address + s->offset;
+ s->dma_length = s->length;
}
+ return nelems;
+
+out_unmap:
+ pr_err("%s: IOMMU mapping error in map_sg (io-pages: %d)\n",
+ dev_name(dev), npages);
+
+ for_each_sg(sglist, s, nelems, i) {
+ int j, pages = iommu_num_pages(sg_phys(s), s->length, PAGE_SIZE);
+
+ for (j = 0; j < pages; ++j) {
+ unsigned long bus_addr;
+
+ bus_addr = address + s->dma_address + (j << PAGE_SHIFT);
+ iommu_unmap_page(domain, bus_addr, PAGE_SIZE);
+
+ if (--mapped_pages)
+ goto out_free_iova;
+ }
+ }
+
+out_free_iova:
+ free_iova_fast(&dma_dom->iovad, address, npages);
+
+out_err:
return 0;
}
@@ -2452,18 +2512,17 @@
struct dma_attrs *attrs)
{
struct protection_domain *domain;
- struct scatterlist *s;
- int i;
+ unsigned long startaddr;
+ int npages = 2;
domain = get_domain(dev);
if (IS_ERR(domain))
return;
- 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;
- }
+ startaddr = sg_dma_address(sglist) & PAGE_MASK;
+ npages = sg_num_pages(dev, sglist, nelems);
+
+ __unmap_single(domain->priv, startaddr, npages << PAGE_SHIFT, dir);
}
/*