nfsd: nfsd should drop CAP_MKNOD for non-root
[safe/jmp/linux-2.6] / lib / swiotlb.c
index d568894..1f991ac 100644 (file)
@@ -14,6 +14,7 @@
  * 04/07/.. ak         Better overflow handling. Assorted fixes.
  * 05/09/10 linville   Add support for syncing ranges, support syncing for
  *                     DMA_BIDIRECTIONAL mappings, miscellaneous cleanup.
+ * 08/12/11 beckyb     Add highmem support
  */
 
 #include <linux/cache.h>
 #include <linux/module.h>
 #include <linux/spinlock.h>
 #include <linux/string.h>
+#include <linux/swiotlb.h>
+#include <linux/pfn.h>
 #include <linux/types.h>
 #include <linux/ctype.h>
+#include <linux/highmem.h>
 
 #include <asm/io.h>
 #include <asm/dma.h>
 #define OFFSET(val,align) ((unsigned long)     \
                           ( (val) & ( (align) - 1)))
 
-#define SG_ENT_VIRT_ADDRESS(sg)        (sg_virt((sg)))
-#define SG_ENT_PHYS_ADDRESS(sg)        virt_to_bus(SG_ENT_VIRT_ADDRESS(sg))
-
-/*
- * Maximum allowable number of contiguous slabs to map,
- * must be a power of 2.  What is the appropriate value ?
- * The complexity of {map,unmap}_single is linearly dependent on this value.
- */
-#define IO_TLB_SEGSIZE 128
-
-/*
- * log of the size of each IO TLB slab.  The number of slabs is command line
- * controllable.
- */
-#define IO_TLB_SHIFT 11
-
 #define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT))
 
 /*
@@ -102,7 +90,7 @@ static unsigned int io_tlb_index;
  * We need to save away the original address corresponding to a mapped entry
  * for the sync operations.
  */
-static unsigned char **io_tlb_orig_addr;
+static phys_addr_t *io_tlb_orig_addr;
 
 /*
  * Protect the above data structures in the map and unmap calls
@@ -126,6 +114,56 @@ setup_io_tlb_npages(char *str)
 __setup("swiotlb=", setup_io_tlb_npages);
 /* make io_tlb_overflow tunable too? */
 
+void * __weak __init swiotlb_alloc_boot(size_t size, unsigned long nslabs)
+{
+       return alloc_bootmem_low_pages(size);
+}
+
+void * __weak swiotlb_alloc(unsigned order, unsigned long nslabs)
+{
+       return (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN, order);
+}
+
+dma_addr_t __weak swiotlb_phys_to_bus(struct device *hwdev, phys_addr_t paddr)
+{
+       return paddr;
+}
+
+phys_addr_t __weak swiotlb_bus_to_phys(dma_addr_t baddr)
+{
+       return baddr;
+}
+
+static dma_addr_t swiotlb_virt_to_bus(struct device *hwdev,
+                                     volatile void *address)
+{
+       return swiotlb_phys_to_bus(hwdev, virt_to_phys(address));
+}
+
+static void *swiotlb_bus_to_virt(dma_addr_t address)
+{
+       return phys_to_virt(swiotlb_bus_to_phys(address));
+}
+
+int __weak swiotlb_arch_range_needs_mapping(void *ptr, size_t size)
+{
+       return 0;
+}
+
+static void swiotlb_print_info(unsigned long bytes)
+{
+       phys_addr_t pstart, pend;
+
+       pstart = virt_to_phys(io_tlb_start);
+       pend = virt_to_phys(io_tlb_end);
+
+       printk(KERN_INFO "Placing %luMB software IO TLB between %p - %p\n",
+              bytes >> 20, io_tlb_start, io_tlb_end);
+       printk(KERN_INFO "software IO TLB at phys %#llx - %#llx\n",
+              (unsigned long long)pstart,
+              (unsigned long long)pend);
+}
+
 /*
  * Statically reserve bounce buffer space and initialize bounce buffer data
  * structures for the software IO TLB used to implement the DMA API.
@@ -145,7 +183,7 @@ swiotlb_init_with_default_size(size_t default_size)
        /*
         * Get IO TLB memory from the low pages
         */
-       io_tlb_start = alloc_bootmem_low_pages(bytes);
+       io_tlb_start = swiotlb_alloc_boot(bytes, io_tlb_nslabs);
        if (!io_tlb_start)
                panic("Cannot allocate SWIOTLB buffer");
        io_tlb_end = io_tlb_start + bytes;
@@ -159,7 +197,7 @@ swiotlb_init_with_default_size(size_t default_size)
        for (i = 0; i < io_tlb_nslabs; i++)
                io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
        io_tlb_index = 0;
-       io_tlb_orig_addr = alloc_bootmem(io_tlb_nslabs * sizeof(char *));
+       io_tlb_orig_addr = alloc_bootmem(io_tlb_nslabs * sizeof(phys_addr_t));
 
        /*
         * Get the overflow emergency buffer
@@ -168,8 +206,7 @@ swiotlb_init_with_default_size(size_t default_size)
        if (!io_tlb_overflow_buffer)
                panic("Cannot allocate SWIOTLB overflow buffer!\n");
 
-       printk(KERN_INFO "Placing software IO TLB between 0x%lx - 0x%lx\n",
-              virt_to_bus(io_tlb_start), virt_to_bus(io_tlb_end));
+       swiotlb_print_info(bytes);
 }
 
 void __init
@@ -202,8 +239,7 @@ swiotlb_late_init_with_default_size(size_t default_size)
        bytes = io_tlb_nslabs << IO_TLB_SHIFT;
 
        while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
-               io_tlb_start = (char *)__get_free_pages(GFP_DMA | __GFP_NOWARN,
-                                                       order);
+               io_tlb_start = swiotlb_alloc(order, io_tlb_nslabs);
                if (io_tlb_start)
                        break;
                order--;
@@ -235,12 +271,14 @@ swiotlb_late_init_with_default_size(size_t default_size)
                io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
        io_tlb_index = 0;
 
-       io_tlb_orig_addr = (unsigned char **)__get_free_pages(GFP_KERNEL,
-                                  get_order(io_tlb_nslabs * sizeof(char *)));
+       io_tlb_orig_addr = (phys_addr_t *)
+               __get_free_pages(GFP_KERNEL,
+                                get_order(io_tlb_nslabs *
+                                          sizeof(phys_addr_t)));
        if (!io_tlb_orig_addr)
                goto cleanup3;
 
-       memset(io_tlb_orig_addr, 0, io_tlb_nslabs * sizeof(char *));
+       memset(io_tlb_orig_addr, 0, io_tlb_nslabs * sizeof(phys_addr_t));
 
        /*
         * Get the overflow emergency buffer
@@ -250,15 +288,13 @@ swiotlb_late_init_with_default_size(size_t default_size)
        if (!io_tlb_overflow_buffer)
                goto cleanup4;
 
-       printk(KERN_INFO "Placing %luMB software IO TLB between 0x%lx - "
-              "0x%lx\n", bytes >> 20,
-              virt_to_bus(io_tlb_start), virt_to_bus(io_tlb_end));
+       swiotlb_print_info(bytes);
 
        return 0;
 
 cleanup4:
-       free_pages((unsigned long)io_tlb_orig_addr, get_order(io_tlb_nslabs *
-                                                             sizeof(char *)));
+       free_pages((unsigned long)io_tlb_orig_addr,
+                  get_order(io_tlb_nslabs * sizeof(phys_addr_t)));
        io_tlb_orig_addr = NULL;
 cleanup3:
        free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
@@ -274,20 +310,67 @@ cleanup1:
 }
 
 static int
-address_needs_mapping(struct device *hwdev, dma_addr_t addr)
+address_needs_mapping(struct device *hwdev, dma_addr_t addr, size_t size)
+{
+       return !is_buffer_dma_capable(dma_get_mask(hwdev), addr, size);
+}
+
+static inline int range_needs_mapping(void *ptr, size_t size)
 {
-       dma_addr_t mask = 0xffffffff;
-       /* If the device has a mask, use it, otherwise default to 32 bits */
-       if (hwdev && hwdev->dma_mask)
-               mask = *hwdev->dma_mask;
-       return (addr & ~mask) != 0;
+       return swiotlb_force || swiotlb_arch_range_needs_mapping(ptr, size);
+}
+
+static int is_swiotlb_buffer(char *addr)
+{
+       return addr >= io_tlb_start && addr < io_tlb_end;
+}
+
+/*
+ * Bounce: copy the swiotlb buffer back to the original dma location
+ */
+static void swiotlb_bounce(phys_addr_t phys, char *dma_addr, size_t size,
+                          enum dma_data_direction dir)
+{
+       unsigned long pfn = PFN_DOWN(phys);
+
+       if (PageHighMem(pfn_to_page(pfn))) {
+               /* The buffer does not have a mapping.  Map it in and copy */
+               unsigned int offset = phys & ~PAGE_MASK;
+               char *buffer;
+               unsigned int sz = 0;
+               unsigned long flags;
+
+               while (size) {
+                       sz = min(PAGE_SIZE - offset, size);
+
+                       local_irq_save(flags);
+                       buffer = kmap_atomic(pfn_to_page(pfn),
+                                            KM_BOUNCE_READ);
+                       if (dir == DMA_TO_DEVICE)
+                               memcpy(dma_addr, buffer + offset, sz);
+                       else
+                               memcpy(buffer + offset, dma_addr, sz);
+                       kunmap_atomic(buffer, KM_BOUNCE_READ);
+                       local_irq_restore(flags);
+
+                       size -= sz;
+                       pfn++;
+                       dma_addr += sz;
+                       offset = 0;
+               }
+       } else {
+               if (dir == DMA_TO_DEVICE)
+                       memcpy(dma_addr, phys_to_virt(phys), size);
+               else
+                       memcpy(phys_to_virt(phys), dma_addr, size);
+       }
 }
 
 /*
  * Allocates bounce buffer and returns its kernel virtual address.
  */
 static void *
-map_single(struct device *hwdev, char *buffer, size_t size, int dir)
+map_single(struct device *hwdev, phys_addr_t phys, size_t size, int dir)
 {
        unsigned long flags;
        char *dma_addr;
@@ -299,9 +382,13 @@ map_single(struct device *hwdev, char *buffer, size_t size, int dir)
        unsigned long max_slots;
 
        mask = dma_get_seg_boundary(hwdev);
-       start_dma_addr = virt_to_bus(io_tlb_start) & mask;
+       start_dma_addr = swiotlb_virt_to_bus(hwdev, io_tlb_start) & mask;
 
        offset_slots = ALIGN(start_dma_addr, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
+
+       /*
+        * Carefully handle integer overflow which can occur when mask == ~0UL.
+        */
        max_slots = mask + 1
                    ? ALIGN(mask + 1, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT
                    : 1UL << (BITS_PER_LONG - IO_TLB_SHIFT);
@@ -378,9 +465,9 @@ found:
         * needed.
         */
        for (i = 0; i < nslots; i++)
-               io_tlb_orig_addr[index+i] = buffer + (i << IO_TLB_SHIFT);
+               io_tlb_orig_addr[index+i] = phys + (i << IO_TLB_SHIFT);
        if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)
-               memcpy(dma_addr, buffer, size);
+               swiotlb_bounce(phys, dma_addr, size, DMA_TO_DEVICE);
 
        return dma_addr;
 }
@@ -394,17 +481,13 @@ unmap_single(struct device *hwdev, char *dma_addr, size_t size, int dir)
        unsigned long flags;
        int i, count, nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
        int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT;
-       char *buffer = io_tlb_orig_addr[index];
+       phys_addr_t phys = io_tlb_orig_addr[index];
 
        /*
         * First, sync the memory before unmapping the entry
         */
-       if (buffer && ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL)))
-               /*
-                * bounce... copy the data back into the original buffer * and
-                * delete the bounce buffer.
-                */
-               memcpy(buffer, dma_addr, size);
+       if (phys && ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL)))
+               swiotlb_bounce(phys, dma_addr, size, DMA_FROM_DEVICE);
 
        /*
         * Return the buffer to the free list by setting the corresponding
@@ -437,20 +520,20 @@ sync_single(struct device *hwdev, char *dma_addr, size_t size,
            int dir, int target)
 {
        int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT;
-       char *buffer = io_tlb_orig_addr[index];
+       phys_addr_t phys = io_tlb_orig_addr[index];
 
-       buffer += ((unsigned long)dma_addr & ((1 << IO_TLB_SHIFT) - 1));
+       phys += ((unsigned long)dma_addr & ((1 << IO_TLB_SHIFT) - 1));
 
        switch (target) {
        case SYNC_FOR_CPU:
                if (likely(dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL))
-                       memcpy(buffer, dma_addr, size);
+                       swiotlb_bounce(phys, dma_addr, size, DMA_FROM_DEVICE);
                else
                        BUG_ON(dir != DMA_TO_DEVICE);
                break;
        case SYNC_FOR_DEVICE:
                if (likely(dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL))
-                       memcpy(dma_addr, buffer, size);
+                       swiotlb_bounce(phys, dma_addr, size, DMA_TO_DEVICE);
                else
                        BUG_ON(dir != DMA_FROM_DEVICE);
                break;
@@ -466,16 +549,15 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
        dma_addr_t dev_addr;
        void *ret;
        int order = get_order(size);
+       u64 dma_mask = DMA_32BIT_MASK;
 
-       /*
-        * XXX fix me: the DMA API should pass us an explicit DMA mask
-        * instead, or use ZONE_DMA32 (ia64 overloads ZONE_DMA to be a ~32
-        * bit range instead of a 16MB one).
-        */
-       flags |= GFP_DMA;
+       if (hwdev && hwdev->coherent_dma_mask)
+               dma_mask = hwdev->coherent_dma_mask;
 
        ret = (void *)__get_free_pages(flags, order);
-       if (ret && address_needs_mapping(hwdev, virt_to_bus(ret))) {
+       if (ret &&
+           !is_buffer_dma_capable(dma_mask, swiotlb_virt_to_bus(hwdev, ret),
+                                  size)) {
                /*
                 * The allocated memory isn't reachable by the device.
                 * Fall back on swiotlb_map_single().
@@ -490,41 +572,41 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
                 * swiotlb_map_single(), which will grab memory from
                 * the lowest available address range.
                 */
-               dma_addr_t handle;
-               handle = swiotlb_map_single(NULL, NULL, size, DMA_FROM_DEVICE);
-               if (swiotlb_dma_mapping_error(handle))
+               ret = map_single(hwdev, 0, size, DMA_FROM_DEVICE);
+               if (!ret)
                        return NULL;
-
-               ret = bus_to_virt(handle);
        }
 
        memset(ret, 0, size);
-       dev_addr = virt_to_bus(ret);
+       dev_addr = swiotlb_virt_to_bus(hwdev, ret);
 
        /* Confirm address can be DMA'd by device */
-       if (address_needs_mapping(hwdev, dev_addr)) {
+       if (!is_buffer_dma_capable(dma_mask, dev_addr, size)) {
                printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n",
-                      (unsigned long long)*hwdev->dma_mask,
+                      (unsigned long long)dma_mask,
                       (unsigned long long)dev_addr);
-               panic("swiotlb_alloc_coherent: allocated memory is out of "
-                     "range for device");
+
+               /* DMA_TO_DEVICE to avoid memcpy in unmap_single */
+               unmap_single(hwdev, ret, size, DMA_TO_DEVICE);
+               return NULL;
        }
        *dma_handle = dev_addr;
        return ret;
 }
+EXPORT_SYMBOL(swiotlb_alloc_coherent);
 
 void
 swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
                      dma_addr_t dma_handle)
 {
        WARN_ON(irqs_disabled());
-       if (!(vaddr >= (void *)io_tlb_start
-                    && vaddr < (void *)io_tlb_end))
+       if (!is_swiotlb_buffer(vaddr))
                free_pages((unsigned long) vaddr, get_order(size));
        else
                /* DMA_TO_DEVICE to avoid memcpy in unmap_single */
-               swiotlb_unmap_single (hwdev, dma_handle, size, DMA_TO_DEVICE);
+               unmap_single(hwdev, vaddr, size, DMA_TO_DEVICE);
 }
+EXPORT_SYMBOL(swiotlb_free_coherent);
 
 static void
 swiotlb_full(struct device *dev, size_t size, int dir, int do_panic)
@@ -537,7 +619,7 @@ swiotlb_full(struct device *dev, size_t size, int dir, int do_panic)
         * the damage, or panic when the transfer is too big.
         */
        printk(KERN_ERR "DMA: Out of SW-IOMMU space for %zu bytes at "
-              "device %s\n", size, dev ? dev->bus_id : "?");
+              "device %s\n", size, dev ? dev_name(dev) : "?");
 
        if (size > io_tlb_overflow && do_panic) {
                if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)
@@ -558,7 +640,7 @@ dma_addr_t
 swiotlb_map_single_attrs(struct device *hwdev, void *ptr, size_t size,
                         int dir, struct dma_attrs *attrs)
 {
-       dma_addr_t dev_addr = virt_to_bus(ptr);
+       dma_addr_t dev_addr = swiotlb_virt_to_bus(hwdev, ptr);
        void *map;
 
        BUG_ON(dir == DMA_NONE);
@@ -567,24 +649,25 @@ swiotlb_map_single_attrs(struct device *hwdev, void *ptr, size_t size,
         * we can safely return the device addr and not worry about bounce
         * buffering it.
         */
-       if (!address_needs_mapping(hwdev, dev_addr) && !swiotlb_force)
+       if (!address_needs_mapping(hwdev, dev_addr, size) &&
+           !range_needs_mapping(ptr, size))
                return dev_addr;
 
        /*
         * Oh well, have to allocate and map a bounce buffer.
         */
-       map = map_single(hwdev, ptr, size, dir);
+       map = map_single(hwdev, virt_to_phys(ptr), size, dir);
        if (!map) {
                swiotlb_full(hwdev, size, dir, 1);
                map = io_tlb_overflow_buffer;
        }
 
-       dev_addr = virt_to_bus(map);
+       dev_addr = swiotlb_virt_to_bus(hwdev, map);
 
        /*
         * Ensure that the address returned is DMA'ble
         */
-       if (address_needs_mapping(hwdev, dev_addr))
+       if (address_needs_mapping(hwdev, dev_addr, size))
                panic("map_single: bounce buffer is not DMA'ble");
 
        return dev_addr;
@@ -596,6 +679,7 @@ swiotlb_map_single(struct device *hwdev, void *ptr, size_t size, int dir)
 {
        return swiotlb_map_single_attrs(hwdev, ptr, size, dir, NULL);
 }
+EXPORT_SYMBOL(swiotlb_map_single);
 
 /*
  * Unmap a single streaming mode DMA translation.  The dma_addr and size must
@@ -609,10 +693,10 @@ void
 swiotlb_unmap_single_attrs(struct device *hwdev, dma_addr_t dev_addr,
                           size_t size, int dir, struct dma_attrs *attrs)
 {
-       char *dma_addr = bus_to_virt(dev_addr);
+       char *dma_addr = swiotlb_bus_to_virt(dev_addr);
 
        BUG_ON(dir == DMA_NONE);
-       if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end)
+       if (is_swiotlb_buffer(dma_addr))
                unmap_single(hwdev, dma_addr, size, dir);
        else if (dir == DMA_FROM_DEVICE)
                dma_mark_clean(dma_addr, size);
@@ -625,6 +709,8 @@ swiotlb_unmap_single(struct device *hwdev, dma_addr_t dev_addr, size_t size,
 {
        return swiotlb_unmap_single_attrs(hwdev, dev_addr, size, dir, NULL);
 }
+EXPORT_SYMBOL(swiotlb_unmap_single);
+
 /*
  * Make physical memory consistent for a single streaming mode DMA translation
  * after a transfer.
@@ -639,10 +725,10 @@ static void
 swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr,
                    size_t size, int dir, int target)
 {
-       char *dma_addr = bus_to_virt(dev_addr);
+       char *dma_addr = swiotlb_bus_to_virt(dev_addr);
 
        BUG_ON(dir == DMA_NONE);
-       if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end)
+       if (is_swiotlb_buffer(dma_addr))
                sync_single(hwdev, dma_addr, size, dir, target);
        else if (dir == DMA_FROM_DEVICE)
                dma_mark_clean(dma_addr, size);
@@ -654,6 +740,7 @@ swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr,
 {
        swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_CPU);
 }
+EXPORT_SYMBOL(swiotlb_sync_single_for_cpu);
 
 void
 swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr,
@@ -661,6 +748,7 @@ swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr,
 {
        swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_DEVICE);
 }
+EXPORT_SYMBOL(swiotlb_sync_single_for_device);
 
 /*
  * Same as above, but for a sub-range of the mapping.
@@ -670,10 +758,10 @@ swiotlb_sync_single_range(struct device *hwdev, dma_addr_t dev_addr,
                          unsigned long offset, size_t size,
                          int dir, int target)
 {
-       char *dma_addr = bus_to_virt(dev_addr) + offset;
+       char *dma_addr = swiotlb_bus_to_virt(dev_addr) + offset;
 
        BUG_ON(dir == DMA_NONE);
-       if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end)
+       if (is_swiotlb_buffer(dma_addr))
                sync_single(hwdev, dma_addr, size, dir, target);
        else if (dir == DMA_FROM_DEVICE)
                dma_mark_clean(dma_addr, size);
@@ -686,6 +774,7 @@ swiotlb_sync_single_range_for_cpu(struct device *hwdev, dma_addr_t dev_addr,
        swiotlb_sync_single_range(hwdev, dev_addr, offset, size, dir,
                                  SYNC_FOR_CPU);
 }
+EXPORT_SYMBOL_GPL(swiotlb_sync_single_range_for_cpu);
 
 void
 swiotlb_sync_single_range_for_device(struct device *hwdev, dma_addr_t dev_addr,
@@ -694,9 +783,8 @@ swiotlb_sync_single_range_for_device(struct device *hwdev, dma_addr_t dev_addr,
        swiotlb_sync_single_range(hwdev, dev_addr, offset, size, dir,
                                  SYNC_FOR_DEVICE);
 }
+EXPORT_SYMBOL_GPL(swiotlb_sync_single_range_for_device);
 
-void swiotlb_unmap_sg_attrs(struct device *, struct scatterlist *, int, int,
-                           struct dma_attrs *);
 /*
  * Map a set of buffers described by scatterlist in streaming mode for DMA.
  * This is the scatter-gather version of the above swiotlb_map_single
@@ -718,17 +806,18 @@ swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
                     int dir, struct dma_attrs *attrs)
 {
        struct scatterlist *sg;
-       void *addr;
-       dma_addr_t dev_addr;
        int i;
 
        BUG_ON(dir == DMA_NONE);
 
        for_each_sg(sgl, sg, nelems, i) {
-               addr = SG_ENT_VIRT_ADDRESS(sg);
-               dev_addr = virt_to_bus(addr);
-               if (swiotlb_force || address_needs_mapping(hwdev, dev_addr)) {
-                       void *map = map_single(hwdev, addr, sg->length, dir);
+               void *addr = sg_virt(sg);
+               dma_addr_t dev_addr = swiotlb_virt_to_bus(hwdev, addr);
+
+               if (range_needs_mapping(addr, sg->length) ||
+                   address_needs_mapping(hwdev, dev_addr, sg->length)) {
+                       void *map = map_single(hwdev, sg_phys(sg),
+                                              sg->length, dir);
                        if (!map) {
                                /* Don't panic here, we expect map_sg users
                                   to do proper error handling. */
@@ -738,7 +827,7 @@ swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
                                sgl[0].dma_length = 0;
                                return 0;
                        }
-                       sg->dma_address = virt_to_bus(map);
+                       sg->dma_address = swiotlb_virt_to_bus(hwdev, map);
                } else
                        sg->dma_address = dev_addr;
                sg->dma_length = sg->length;
@@ -753,6 +842,7 @@ swiotlb_map_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
 {
        return swiotlb_map_sg_attrs(hwdev, sgl, nelems, dir, NULL);
 }
+EXPORT_SYMBOL(swiotlb_map_sg);
 
 /*
  * Unmap a set of streaming mode DMA translations.  Again, cpu read rules
@@ -768,11 +858,11 @@ swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
        BUG_ON(dir == DMA_NONE);
 
        for_each_sg(sgl, sg, nelems, i) {
-               if (sg->dma_address != SG_ENT_PHYS_ADDRESS(sg))
-                       unmap_single(hwdev, bus_to_virt(sg->dma_address),
+               if (sg->dma_address != swiotlb_virt_to_bus(hwdev, sg_virt(sg)))
+                       unmap_single(hwdev, swiotlb_bus_to_virt(sg->dma_address),
                                     sg->dma_length, dir);
                else if (dir == DMA_FROM_DEVICE)
-                       dma_mark_clean(SG_ENT_VIRT_ADDRESS(sg), sg->dma_length);
+                       dma_mark_clean(sg_virt(sg), sg->dma_length);
        }
 }
 EXPORT_SYMBOL(swiotlb_unmap_sg_attrs);
@@ -783,6 +873,7 @@ swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
 {
        return swiotlb_unmap_sg_attrs(hwdev, sgl, nelems, dir, NULL);
 }
+EXPORT_SYMBOL(swiotlb_unmap_sg);
 
 /*
  * Make physical memory consistent for a set of streaming mode DMA translations
@@ -801,11 +892,11 @@ swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl,
        BUG_ON(dir == DMA_NONE);
 
        for_each_sg(sgl, sg, nelems, i) {
-               if (sg->dma_address != SG_ENT_PHYS_ADDRESS(sg))
-                       sync_single(hwdev, bus_to_virt(sg->dma_address),
+               if (sg->dma_address != swiotlb_virt_to_bus(hwdev, sg_virt(sg)))
+                       sync_single(hwdev, swiotlb_bus_to_virt(sg->dma_address),
                                    sg->dma_length, dir, target);
                else if (dir == DMA_FROM_DEVICE)
-                       dma_mark_clean(SG_ENT_VIRT_ADDRESS(sg), sg->dma_length);
+                       dma_mark_clean(sg_virt(sg), sg->dma_length);
        }
 }
 
@@ -815,6 +906,7 @@ swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg,
 {
        swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_CPU);
 }
+EXPORT_SYMBOL(swiotlb_sync_sg_for_cpu);
 
 void
 swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
@@ -822,12 +914,14 @@ swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
 {
        swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_DEVICE);
 }
+EXPORT_SYMBOL(swiotlb_sync_sg_for_device);
 
 int
-swiotlb_dma_mapping_error(dma_addr_t dma_addr)
+swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr)
 {
-       return (dma_addr == virt_to_bus(io_tlb_overflow_buffer));
+       return (dma_addr == swiotlb_virt_to_bus(hwdev, io_tlb_overflow_buffer));
 }
+EXPORT_SYMBOL(swiotlb_dma_mapping_error);
 
 /*
  * Return whether the given device DMA address mask can be supported
@@ -838,20 +932,6 @@ swiotlb_dma_mapping_error(dma_addr_t dma_addr)
 int
 swiotlb_dma_supported(struct device *hwdev, u64 mask)
 {
-       return virt_to_bus(io_tlb_end - 1) <= mask;
+       return swiotlb_virt_to_bus(hwdev, io_tlb_end - 1) <= mask;
 }
-
-EXPORT_SYMBOL(swiotlb_map_single);
-EXPORT_SYMBOL(swiotlb_unmap_single);
-EXPORT_SYMBOL(swiotlb_map_sg);
-EXPORT_SYMBOL(swiotlb_unmap_sg);
-EXPORT_SYMBOL(swiotlb_sync_single_for_cpu);
-EXPORT_SYMBOL(swiotlb_sync_single_for_device);
-EXPORT_SYMBOL_GPL(swiotlb_sync_single_range_for_cpu);
-EXPORT_SYMBOL_GPL(swiotlb_sync_single_range_for_device);
-EXPORT_SYMBOL(swiotlb_sync_sg_for_cpu);
-EXPORT_SYMBOL(swiotlb_sync_sg_for_device);
-EXPORT_SYMBOL(swiotlb_dma_mapping_error);
-EXPORT_SYMBOL(swiotlb_alloc_coherent);
-EXPORT_SYMBOL(swiotlb_free_coherent);
 EXPORT_SYMBOL(swiotlb_dma_supported);