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>

4 files changed, 21 insertions, 27 deletions

diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 66237fde758f..093bd526c949 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -928,7 +928,7 @@ static unsigned long dma_ops_alloc_addresses(struct device *dev,
         }
 
         if (unlikely(address == -1))
-                address = bad_dma_address;
+                address = DMA_ERROR_CODE;
 
         WARN_ON((address + (PAGE_SIZE*pages)) > dom->aperture_size);
 
@@ -1544,7 +1544,7 @@ static dma_addr_t dma_ops_domain_map(struct amd_iommu *iommu,
 
         pte  = dma_ops_get_pte(dom, address);
         if (!pte)
-                return bad_dma_address;
+                return DMA_ERROR_CODE;
 
         __pte = paddr | IOMMU_PTE_P | IOMMU_PTE_FC;
 
@@ -1625,7 +1625,7 @@ static dma_addr_t __map_single(struct device *dev,
 retry:
         address = dma_ops_alloc_addresses(dev, dma_dom, pages, align_mask,
                                           dma_mask);
-        if (unlikely(address == bad_dma_address)) {
+        if (unlikely(address == DMA_ERROR_CODE)) {
                 /*
                  * setting next_address here will let the address
                  * allocator only scan the new allocated range in the
@@ -1646,7 +1646,7 @@ retry:
         start = address;
         for (i = 0; i < pages; ++i) {
                 ret = dma_ops_domain_map(iommu, dma_dom, start, paddr, dir);
-                if (ret == bad_dma_address)
+                if (ret == DMA_ERROR_CODE)
                         goto out_unmap;
 
                 paddr += PAGE_SIZE;
@@ -1674,7 +1674,7 @@ out_unmap:
 
         dma_ops_free_addresses(dma_dom, address, pages);
 
-        return bad_dma_address;
+        return DMA_ERROR_CODE;
 }
 
 /*
@@ -1690,7 +1690,7 @@ static void __unmap_single(struct amd_iommu *iommu,
         dma_addr_t i, start;
         unsigned int pages;
 
-        if ((dma_addr == bad_dma_address) ||
+        if ((dma_addr == DMA_ERROR_CODE) ||
             (dma_addr + size > dma_dom->aperture_size))
                 return;
 
@@ -1732,7 +1732,7 @@ static dma_addr_t map_page(struct device *dev, struct page *page,
         INC_STATS_COUNTER(cnt_map_single);
 
         if (!check_device(dev))
-                return bad_dma_address;
+                return DMA_ERROR_CODE;
 
         dma_mask = *dev->dma_mask;
 
@@ -1743,12 +1743,12 @@ static dma_addr_t map_page(struct device *dev, struct page *page,
                 return (dma_addr_t)paddr;
 
         if (!dma_ops_domain(domain))
-                return bad_dma_address;
+                return DMA_ERROR_CODE;
 
         spin_lock_irqsave(&domain->lock, flags);
         addr = __map_single(dev, iommu, domain->priv, paddr, size, dir, false,
                             dma_mask);
-        if (addr == bad_dma_address)
+        if (addr == DMA_ERROR_CODE)
                 goto out;
 
         iommu_completion_wait(iommu);
@@ -1957,7 +1957,7 @@ static void *alloc_coherent(struct device *dev, size_t size,
         *dma_addr = __map_single(dev, iommu, domain->priv, paddr,
                                  size, DMA_BIDIRECTIONAL, true, dma_mask);
 
-        if (*dma_addr == bad_dma_address) {
+        if (*dma_addr == DMA_ERROR_CODE) {
                 spin_unlock_irqrestore(&domain->lock, flags);
                 goto out_free;
         }
@@ -2110,7 +2110,6 @@ int __init amd_iommu_init_dma_ops(void)
                 prealloc_protection_domains();
 
         iommu_detected = 1;
-        bad_dma_address = 0;
         swiotlb = 0;
 #ifdef CONFIG_GART_IOMMU
         gart_iommu_aperture_disabled = 1;
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;
 }
 
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index bf621b9ee26e..afcc58b69c7c 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -43,9 +43,6 @@ int iommu_detected __read_mostly = 0;
  */
 int iommu_pass_through __read_mostly;
 
-dma_addr_t bad_dma_address __read_mostly = 0;
-EXPORT_SYMBOL(bad_dma_address);
-
 /* Dummy device used for NULL arguments (normally ISA). */
 struct device x86_dma_fallback_dev = {
         .init_name = "fallback device",
diff --git a/arch/x86/kernel/pci-nommu.c b/arch/x86/kernel/pci-nommu.c
index 875e3822ae61..22be12b60a8f 100644
--- a/arch/x86/kernel/pci-nommu.c
+++ b/arch/x86/kernel/pci-nommu.c
@@ -33,7 +33,7 @@ static dma_addr_t nommu_map_page(struct device *dev, struct page *page,
         dma_addr_t bus = page_to_phys(page) + offset;
         WARN_ON(size == 0);
         if (!check_addr("map_single", dev, bus, size))
-                return bad_dma_address;
+                return DMA_ERROR_CODE;
         flush_write_buffers();
         return bus;
 }