swiotlb: Use physical addresses for swiotlb_tbl_unmap_single

This change makes it so that the unmap functionality also uses physical
addresses.  This helps to further reduce the use of virt_to_phys and
phys_to_virt functions.

In order to clarify things since we now have 2 physical addresses in use
inside of swiotlb_tbl_unmap_single I am renaming phys to orig_addr, and
dma_addr to tlb_addr.  This way is should be clear that orig_addr is
contained within io_orig_addr and tlb_addr is an address within the
io_tlb_addr buffer.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

1 files changed, 19 insertions, 18 deletions

diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 3adc148bb8d8..d7701dcf407f 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -515,20 +515,20 @@ phys_addr_t map_single(struct device *hwdev, phys_addr_t phys, size_t size,
 /*
  * dma_addr is the kernel virtual address of the bounce buffer to unmap.
  */
-void
-swiotlb_tbl_unmap_single(struct device *hwdev, char *dma_addr, size_t size,
-                        enum dma_data_direction dir)
+void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr,
+                              size_t size, enum dma_data_direction dir)
 {
         unsigned long flags;
         int i, count, nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
-        int index = (dma_addr - (char *)phys_to_virt(io_tlb_start)) >> IO_TLB_SHIFT;
-        phys_addr_t phys = io_tlb_orig_addr[index];
+        int index = (tlb_addr - io_tlb_start) >> IO_TLB_SHIFT;
+        phys_addr_t orig_addr = io_tlb_orig_addr[index];
 
         /*
          * First, sync the memory before unmapping the entry
          */
         if (phys && ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL)))
-                swiotlb_bounce(phys, dma_addr, size, DMA_FROM_DEVICE);
+                swiotlb_bounce(orig_addr, phys_to_virt(tlb_addr),
+                               size, DMA_FROM_DEVICE);
 
         /*
          * Return the buffer to the free list by setting the corresponding
@@ -621,17 +621,18 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
 
                 ret = phys_to_virt(paddr);
                 dev_addr = phys_to_dma(hwdev, paddr);
-        }
 
-        /* Confirm address can be DMA'd by device */
-        if (dev_addr + size - 1 > dma_mask) {
-                printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n",
-                       (unsigned long long)dma_mask,
-                       (unsigned long long)dev_addr);
+                /* Confirm address can be DMA'd by device */
+                if (dev_addr + size - 1 > dma_mask) {
+                        printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n",
+                               (unsigned long long)dma_mask,
+                               (unsigned long long)dev_addr);
 
-                /* DMA_TO_DEVICE to avoid memcpy in unmap_single */
-                swiotlb_tbl_unmap_single(hwdev, ret, size, DMA_TO_DEVICE);
-                return NULL;
+                        /* DMA_TO_DEVICE to avoid memcpy in unmap_single */
+                        swiotlb_tbl_unmap_single(hwdev, paddr,
+                                                 size, DMA_TO_DEVICE);
+                        return NULL;
+                }
         }
 
         *dma_handle = dev_addr;
@@ -652,7 +653,7 @@ swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
                 free_pages((unsigned long)vaddr, get_order(size));
         else
                 /* DMA_TO_DEVICE to avoid memcpy in swiotlb_tbl_unmap_single */
-                swiotlb_tbl_unmap_single(hwdev, vaddr, size, DMA_TO_DEVICE);
+                swiotlb_tbl_unmap_single(hwdev, paddr, size, DMA_TO_DEVICE);
 }
 EXPORT_SYMBOL(swiotlb_free_coherent);
 
@@ -716,7 +717,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
 
         /* Ensure that the address returned is DMA'ble */
         if (!dma_capable(dev, dev_addr, size)) {
-                swiotlb_tbl_unmap_single(dev, phys_to_virt(map), size, dir);
+                swiotlb_tbl_unmap_single(dev, map, size, dir);
                 return phys_to_dma(dev, io_tlb_overflow_buffer);
         }
 
@@ -740,7 +741,7 @@ static void unmap_single(struct device *hwdev, dma_addr_t dev_addr,
         BUG_ON(dir == DMA_NONE);
 
         if (is_swiotlb_buffer(paddr)) {
-                swiotlb_tbl_unmap_single(hwdev, phys_to_virt(paddr), size, dir);
+                swiotlb_tbl_unmap_single(hwdev, paddr, size, dir);
                 return;
         }