2 files changed, 106 insertions, 58 deletions

diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 81a4e213c6cf..8c0e349f4a6c 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -23,6 +23,29 @@ extern int swiotlb_force;
 #define IO_TLB_SHIFT 11
 
 extern void swiotlb_init(int verbose);
+extern void swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose);
+
+/*
+ * Enumeration for sync targets
+ */
+enum dma_sync_target {
+        SYNC_FOR_CPU = 0,
+        SYNC_FOR_DEVICE = 1,
+};
+extern void *swiotlb_tbl_map_single(struct device *hwdev, dma_addr_t tbl_dma_addr,
+                                    phys_addr_t phys, size_t size,
+                                    enum dma_data_direction dir);
+
+extern void swiotlb_tbl_unmap_single(struct device *hwdev, char *dma_addr,
+                                     size_t size, enum dma_data_direction dir);
+
+extern void swiotlb_tbl_sync_single(struct device *hwdev, char *dma_addr,
+                                    size_t size, enum dma_data_direction dir,
+                                    enum dma_sync_target target);
+
+/* Accessory functions. */
+extern void swiotlb_bounce(phys_addr_t phys, char *dma_addr, size_t size,
+                           enum dma_data_direction dir);
 
 extern void
 *swiotlb_alloc_coherent(struct device *hwdev, size_t size,
@@ -42,11 +65,11 @@ extern void swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
 
 extern int
 swiotlb_map_sg(struct device *hwdev, struct scatterlist *sg, int nents,
-               int direction);
+               enum dma_data_direction dir);
 
 extern void
 swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sg, int nents,
-                 int direction);
+                 enum dma_data_direction dir);
 
 extern int
 swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index a009055140ec..34e3082632d8 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -50,19 +50,11 @@
  */
 #define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT)
 
-/*
- * Enumeration for sync targets
- */
-enum dma_sync_target {
-        SYNC_FOR_CPU = 0,
-        SYNC_FOR_DEVICE = 1,
-};
-
 int swiotlb_force;
 
 /*
- * Used to do a quick range check in unmap_single and
- * sync_single_*, to see if the memory was in fact allocated by this
+ * Used to do a quick range check in swiotlb_tbl_unmap_single and
+ * swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by this
  * API.
  */
 static char *io_tlb_start, *io_tlb_end;
@@ -140,28 +132,14 @@ void swiotlb_print_info(void)
                (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.
- */
-void __init
-swiotlb_init_with_default_size(size_t default_size, int verbose)
+void __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
 {
         unsigned long i, bytes;
 
-        if (!io_tlb_nslabs) {
-                io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
-                io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
-        }
-
-        bytes = io_tlb_nslabs << IO_TLB_SHIFT;
+        bytes = nslabs << IO_TLB_SHIFT;
 
-        /*
-         * Get IO TLB memory from the low pages
-         */
-        io_tlb_start = alloc_bootmem_low_pages(bytes);
-        if (!io_tlb_start)
-                panic("Cannot allocate SWIOTLB buffer");
+        io_tlb_nslabs = nslabs;
+        io_tlb_start = tlb;
         io_tlb_end = io_tlb_start + bytes;
 
         /*
@@ -185,6 +163,32 @@ swiotlb_init_with_default_size(size_t default_size, int verbose)
                 swiotlb_print_info();
 }
 
+/*
+ * Statically reserve bounce buffer space and initialize bounce buffer data
+ * structures for the software IO TLB used to implement the DMA API.
+ */
+void __init
+swiotlb_init_with_default_size(size_t default_size, int verbose)
+{
+        unsigned long bytes;
+
+        if (!io_tlb_nslabs) {
+                io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
+                io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
+        }
+
+        bytes = io_tlb_nslabs << IO_TLB_SHIFT;
+
+        /*
+         * Get IO TLB memory from the low pages
+         */
+        io_tlb_start = alloc_bootmem_low_pages(bytes);
+        if (!io_tlb_start)
+                panic("Cannot allocate SWIOTLB buffer");
+
+        swiotlb_init_with_tbl(io_tlb_start, io_tlb_nslabs, verbose);
+}
+
 void __init
 swiotlb_init(int verbose)
 {
@@ -323,8 +327,8 @@ static int is_swiotlb_buffer(phys_addr_t paddr)
 /*
  * 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)
+void swiotlb_bounce(phys_addr_t phys, char *dma_addr, size_t size,
+                    enum dma_data_direction dir)
 {
         unsigned long pfn = PFN_DOWN(phys);
 
@@ -360,26 +364,25 @@ static void swiotlb_bounce(phys_addr_t phys, char *dma_addr, size_t size,
                         memcpy(phys_to_virt(phys), dma_addr, size);
         }
 }
+EXPORT_SYMBOL_GPL(swiotlb_bounce);
 
-/*
- * Allocates bounce buffer and returns its kernel virtual address.
- */
-static void *
-map_single(struct device *hwdev, phys_addr_t phys, size_t size, int dir)
+void *swiotlb_tbl_map_single(struct device *hwdev, dma_addr_t tbl_dma_addr,
+                             phys_addr_t phys, size_t size,
+                             enum dma_data_direction dir)
 {
         unsigned long flags;
         char *dma_addr;
         unsigned int nslots, stride, index, wrap;
         int i;
-        unsigned long start_dma_addr;
         unsigned long mask;
         unsigned long offset_slots;
         unsigned long max_slots;
 
         mask = dma_get_seg_boundary(hwdev);
-        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;
+        tbl_dma_addr &= mask;
+
+        offset_slots = ALIGN(tbl_dma_addr, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
 
         /*
          * Carefully handle integer overflow which can occur when mask == ~0UL.
@@ -466,12 +469,27 @@ found:
 
         return dma_addr;
 }
+EXPORT_SYMBOL_GPL(swiotlb_tbl_map_single);
+
+/*
+ * Allocates bounce buffer and returns its kernel virtual address.
+ */
+
+static void *
+map_single(struct device *hwdev, phys_addr_t phys, size_t size,
+           enum dma_data_direction dir)
+{
+        dma_addr_t start_dma_addr = swiotlb_virt_to_bus(hwdev, io_tlb_start);
+
+        return swiotlb_tbl_map_single(hwdev, start_dma_addr, phys, size, dir);
+}
 
 /*
  * dma_addr is the kernel virtual address of the bounce buffer to unmap.
  */
-static void
-do_unmap_single(struct device *hwdev, char *dma_addr, size_t size, int dir)
+void
+swiotlb_tbl_unmap_single(struct device *hwdev, char *dma_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;
@@ -509,10 +527,12 @@ do_unmap_single(struct device *hwdev, char *dma_addr, size_t size, int dir)
         }
         spin_unlock_irqrestore(&io_tlb_lock, flags);
 }
+EXPORT_SYMBOL_GPL(swiotlb_tbl_unmap_single);
 
-static void
-sync_single(struct device *hwdev, char *dma_addr, size_t size,
-            int dir, int target)
+void
+swiotlb_tbl_sync_single(struct device *hwdev, char *dma_addr, size_t size,
+                        enum dma_data_direction dir,
+                        enum dma_sync_target target)
 {
         int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT;
         phys_addr_t phys = io_tlb_orig_addr[index];
@@ -536,6 +556,7 @@ sync_single(struct device *hwdev, char *dma_addr, size_t size,
                 BUG();
         }
 }
+EXPORT_SYMBOL_GPL(swiotlb_tbl_sync_single);
 
 void *
 swiotlb_alloc_coherent(struct device *hwdev, size_t size,
@@ -559,8 +580,8 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
         }
         if (!ret) {
                 /*
-                 * We are either out of memory or the device can't DMA
-                 * to GFP_DMA memory; fall back on map_single(), which
+                 * We are either out of memory or the device can't DMA to
+                 * GFP_DMA memory; fall back on map_single(), which
                  * will grab memory from the lowest available address range.
                  */
                 ret = map_single(hwdev, 0, size, DMA_FROM_DEVICE);
@@ -578,7 +599,7 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
                        (unsigned long long)dev_addr);
 
                 /* DMA_TO_DEVICE to avoid memcpy in unmap_single */
-                do_unmap_single(hwdev, ret, size, DMA_TO_DEVICE);
+                swiotlb_tbl_unmap_single(hwdev, ret, size, DMA_TO_DEVICE);
                 return NULL;
         }
         *dma_handle = dev_addr;
@@ -596,13 +617,14 @@ swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
         if (!is_swiotlb_buffer(paddr))
                 free_pages((unsigned long)vaddr, get_order(size));
         else
-                /* DMA_TO_DEVICE to avoid memcpy in unmap_single */
-                do_unmap_single(hwdev, vaddr, size, DMA_TO_DEVICE);
+                /* DMA_TO_DEVICE to avoid memcpy in swiotlb_tbl_unmap_single */
+                swiotlb_tbl_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)
+swiotlb_full(struct device *dev, size_t size, enum dma_data_direction dir,
+             int do_panic)
 {
         /*
          * Ran out of IOMMU space for this operation. This is very bad.
@@ -680,14 +702,14 @@ EXPORT_SYMBOL_GPL(swiotlb_map_page);
  * whatever the device wrote there.
  */
 static void unmap_single(struct device *hwdev, dma_addr_t dev_addr,
-                         size_t size, int dir)
+                         size_t size, enum dma_data_direction dir)
 {
         phys_addr_t paddr = dma_to_phys(hwdev, dev_addr);
 
         BUG_ON(dir == DMA_NONE);
 
         if (is_swiotlb_buffer(paddr)) {
-                do_unmap_single(hwdev, phys_to_virt(paddr), size, dir);
+                swiotlb_tbl_unmap_single(hwdev, phys_to_virt(paddr), size, dir);
                 return;
         }
 
@@ -723,14 +745,16 @@ EXPORT_SYMBOL_GPL(swiotlb_unmap_page);
  */
 static void
 swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr,
-                    size_t size, int dir, int target)
+                    size_t size, enum dma_data_direction dir,
+                    enum dma_sync_target target)
 {
         phys_addr_t paddr = dma_to_phys(hwdev, dev_addr);
 
         BUG_ON(dir == DMA_NONE);
 
         if (is_swiotlb_buffer(paddr)) {
-                sync_single(hwdev, phys_to_virt(paddr), size, dir, target);
+                swiotlb_tbl_sync_single(hwdev, phys_to_virt(paddr), size, dir,
+                                       target);
                 return;
         }
 
@@ -809,7 +833,7 @@ EXPORT_SYMBOL(swiotlb_map_sg_attrs);
 
 int
 swiotlb_map_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
-               int dir)
+               enum dma_data_direction dir)
 {
         return swiotlb_map_sg_attrs(hwdev, sgl, nelems, dir, NULL);
 }
@@ -836,7 +860,7 @@ EXPORT_SYMBOL(swiotlb_unmap_sg_attrs);
 
 void
 swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
-                 int dir)
+                 enum dma_data_direction dir)
 {
         return swiotlb_unmap_sg_attrs(hwdev, sgl, nelems, dir, NULL);
 }
@@ -851,7 +875,8 @@ EXPORT_SYMBOL(swiotlb_unmap_sg);
  */
 static void
 swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl,
-                int nelems, int dir, int target)
+                int nelems, enum dma_data_direction dir,
+                enum dma_sync_target target)
 {
         struct scatterlist *sg;
         int i;