iommu/amd: Make use of the per-domain flush queue

Fill the flush-queue on unmap and only flush the IOMMU and
device TLBs when a per-cpu queue gets full.

Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 2418fcc..9fafc30 100644 (file)
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -1806,6 +1806,61 @@ static int dma_ops_domain_alloc_flush_queue(struct dma_ops_domain *dom)
        return 0;
 }
 
+static inline bool queue_ring_full(struct flush_queue *queue)
+{
+       return (((queue->tail + 1) % FLUSH_QUEUE_SIZE) == queue->head);
+}
+
+#define queue_ring_for_each(i, q) \
+       for (i = (q)->head; i != (q)->tail; i = (i + 1) % FLUSH_QUEUE_SIZE)
+
+static void queue_release(struct dma_ops_domain *dom,
+                         struct flush_queue *queue)
+{
+       unsigned i;
+
+       queue_ring_for_each(i, queue)
+               free_iova_fast(&dom->iovad,
+                              queue->entries[i].iova_pfn,
+                              queue->entries[i].pages);
+
+       queue->head = queue->tail = 0;
+}
+
+static inline unsigned queue_ring_add(struct flush_queue *queue)
+{
+       unsigned idx = queue->tail;
+
+       queue->tail = (idx + 1) % FLUSH_QUEUE_SIZE;
+
+       return idx;
+}
+
+static void queue_add(struct dma_ops_domain *dom,
+                     unsigned long address, unsigned long pages)
+{
+       struct flush_queue *queue;
+       int idx;
+
+       pages     = __roundup_pow_of_two(pages);
+       address >>= PAGE_SHIFT;
+
+       queue = get_cpu_ptr(dom->flush_queue);
+
+       if (queue_ring_full(queue)) {
+               domain_flush_tlb(&dom->domain);
+               domain_flush_complete(&dom->domain);
+               queue_release(dom, queue);
+       }
+
+       idx = queue_ring_add(queue);
+
+       queue->entries[idx].iova_pfn = address;
+       queue->entries[idx].pages    = pages;
+
+       put_cpu_ptr(dom->flush_queue);
+}
+
 /*
  * Free a domain, only used if something went wrong in the
  * allocation path and we need to free an already allocated page table
@@ -2454,10 +2509,7 @@ static void __unmap_single(struct dma_ops_domain *dma_dom,
                domain_flush_tlb(&dma_dom->domain);
                domain_flush_complete(&dma_dom->domain);
        } else {
-               /* Keep the if() around, we need it later again */
-               dma_ops_free_iova(dma_dom, dma_addr, pages);
-               domain_flush_tlb(&dma_dom->domain);
-               domain_flush_complete(&dma_dom->domain);
+               queue_add(dma_dom, dma_addr, pages);
        }
 }