x86: Kill bad_dma_address variable

This kills bad_dma_address variable, the old mechanism to enable
IOMMU drivers to make dma_mapping_error() work in IOMMU's
specific way.

bad_dma_address variable was introduced to enable IOMMU drivers
to make dma_mapping_error() work in IOMMU's specific way.
However, it can't handle systems that use both swiotlb and HW
IOMMU. SO we introduced dma_map_ops->mapping_error to solve that
case.

Intel VT-d, GART, and swiotlb already use
dma_map_ops->mapping_error. Calgary, AMD IOMMU, and nommu use
zero for an error dma address. This adds DMA_ERROR_CODE and
converts them to use it (as SPARC and POWER does).

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: muli@il.ibm.com
Cc: joerg.roedel@amd.com
LKML-Reference: <1258287594-8777-3-git-send-email-fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 10 insertions, 12 deletions

diff --git a/arch/x86/kernel/pci-calgary_64.c b/arch/x86/kernel/pci-calgary_64.c
index c84ad037f586..af9f436096a2 100644
--- a/arch/x86/kernel/pci-calgary_64.c
+++ b/arch/x86/kernel/pci-calgary_64.c
@@ -245,7 +245,7 @@ static unsigned long iommu_range_alloc(struct device *dev,
                         if (panic_on_overflow)
                                 panic("Calgary: fix the allocator.\n");
                         else
-                                return bad_dma_address;
+                                return DMA_ERROR_CODE;
                 }
         }
 
@@ -261,11 +261,11 @@ static dma_addr_t iommu_alloc(struct device *dev, struct iommu_table *tbl,
                               void *vaddr, unsigned int npages, int direction)
 {
         unsigned long entry;
-        dma_addr_t ret = bad_dma_address;
+        dma_addr_t ret = DMA_ERROR_CODE;
 
         entry = iommu_range_alloc(dev, tbl, npages);
 
-        if (unlikely(entry == bad_dma_address))
+        if (unlikely(entry == DMA_ERROR_CODE))
                 goto error;
 
         /* set the return dma address */
@@ -280,7 +280,7 @@ static dma_addr_t iommu_alloc(struct device *dev, struct iommu_table *tbl,
 error:
         printk(KERN_WARNING "Calgary: failed to allocate %u pages in "
                "iommu %p\n", npages, tbl);
-        return bad_dma_address;
+        return DMA_ERROR_CODE;
 }
 
 static void iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
@@ -291,8 +291,8 @@ static void iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
         unsigned long flags;
 
         /* were we called with bad_dma_address? */
-        badend = bad_dma_address + (EMERGENCY_PAGES * PAGE_SIZE);
-        if (unlikely((dma_addr >= bad_dma_address) && (dma_addr < badend))) {
+        badend = DMA_ERROR_CODE + (EMERGENCY_PAGES * PAGE_SIZE);
+        if (unlikely((dma_addr >= DMA_ERROR_CODE) && (dma_addr < badend))) {
                 WARN(1, KERN_ERR "Calgary: driver tried unmapping bad DMA "
                        "address 0x%Lx\n", dma_addr);
                 return;
@@ -374,7 +374,7 @@ static int calgary_map_sg(struct device *dev, struct scatterlist *sg,
                 npages = iommu_num_pages(vaddr, s->length, PAGE_SIZE);
 
                 entry = iommu_range_alloc(dev, tbl, npages);
-                if (entry == bad_dma_address) {
+                if (entry == DMA_ERROR_CODE) {
                         /* makes sure unmap knows to stop */
                         s->dma_length = 0;
                         goto error;
@@ -392,7 +392,7 @@ static int calgary_map_sg(struct device *dev, struct scatterlist *sg,
 error:
         calgary_unmap_sg(dev, sg, nelems, dir, NULL);
         for_each_sg(sg, s, nelems, i) {
-                sg->dma_address = bad_dma_address;
+                sg->dma_address = DMA_ERROR_CODE;
                 sg->dma_length = 0;
         }
         return 0;
@@ -447,7 +447,7 @@ static void* calgary_alloc_coherent(struct device *dev, size_t size,
 
         /* set up tces to cover the allocated range */
         mapping = iommu_alloc(dev, tbl, ret, npages, DMA_BIDIRECTIONAL);
-        if (mapping == bad_dma_address)
+        if (mapping == DMA_ERROR_CODE)
                 goto free;
         *dma_handle = mapping;
         return ret;
@@ -728,7 +728,7 @@ static void __init calgary_reserve_regions(struct pci_dev *dev)
         struct iommu_table *tbl = pci_iommu(dev->bus);
 
         /* reserve EMERGENCY_PAGES from bad_dma_address and up */
-        iommu_range_reserve(tbl, bad_dma_address, EMERGENCY_PAGES);
+        iommu_range_reserve(tbl, DMA_ERROR_CODE, EMERGENCY_PAGES);
 
         /* avoid the BIOS/VGA first 640KB-1MB region */
         /* for CalIOC2 - avoid the entire first MB */
@@ -1359,8 +1359,6 @@ static int __init calgary_iommu_init(void)
                 return ret;
         }
 
-        bad_dma_address = 0x0;
-
         return 0;
 }