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>

diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 8a6035a..4cedc28 100644 (file)
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -364,7 +364,7 @@ dma_addr_t xen_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);
                dev_addr = 0;
        }
        return dev_addr;
@@ -388,7 +388,7 @@ static void xen_unmap_single(struct device *hwdev, dma_addr_t dev_addr,
 
        /* NOTE: We use dev_addr here, not paddr! */
        if (is_xen_swiotlb_buffer(dev_addr)) {
-               swiotlb_tbl_unmap_single(hwdev, phys_to_virt(paddr), size, dir);
+               swiotlb_tbl_unmap_single(hwdev, paddr, size, dir);
                return;
        }
 

diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 1995f3e..291643c 100644 (file)
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -43,7 +43,8 @@ extern phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
                                          phys_addr_t phys, size_t size,
                                          enum dma_data_direction dir);
 
-extern void swiotlb_tbl_unmap_single(struct device *hwdev, char *dma_addr,
+extern void swiotlb_tbl_unmap_single(struct device *hwdev,
+                                    phys_addr_t tlb_addr,
                                     size_t size, enum dma_data_direction dir);
 
 extern void swiotlb_tbl_sync_single(struct device *hwdev, char *dma_addr,

diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 3adc148..d7701dc 100644 (file)
--- 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;
        }