vserver 1.9.3

[linux-2.6.git] / arch / arm / common / dmabounce.c

diff --git a/arch/arm/common/dmabounce.c b/arch/arm/common/dmabounce.c
index c3a8766..5797b1b 100644 (file)
--- a/arch/arm/common/dmabounce.c
+++ b/arch/arm/common/dmabounce.c
@@ -121,9 +121,9 @@ alloc_safe_buffer(struct dmabounce_device_info *device_info, void *ptr,
        DO_STATS ( device_info->total_allocs++ );
 
        buf = kmalloc(sizeof(struct safe_buffer), GFP_ATOMIC);
-       if (buf == 0) {
+       if (buf == NULL) {
                dev_warn(dev, "%s: kmalloc failed\n", __func__);
-               return 0;
+               return NULL;
        }
 
        if (size <= device_info->small_buffer_size) {
@@ -137,16 +137,16 @@ alloc_safe_buffer(struct dmabounce_device_info *device_info, void *ptr,
 
                DO_STATS ( device_info->lbp_allocs++ );
        } else {
-               pool = 0;
+               pool = NULL;
                safe = dma_alloc_coherent(dev, size, &safe_dma_addr, GFP_ATOMIC);
        }
 
-       if (safe == 0) {
+       if (safe == NULL) {
                dev_warn(device_info->dev,
                        "%s: could not alloc dma memory (size=%d)\n",
                       __func__, size);
                kfree(buf);
-               return 0;
+               return NULL;
        }
 
 #ifdef STATS
@@ -216,27 +216,33 @@ static inline dma_addr_t
 map_single(struct device *dev, void *ptr, size_t size,
                enum dma_data_direction dir)
 {
-       dma_addr_t dma_addr;
        struct dmabounce_device_info *device_info = find_dmabounce_dev(dev);
+       dma_addr_t dma_addr;
+       int needs_bounce = 0;
 
        if (device_info)
                DO_STATS ( device_info->map_op_count++ );
 
+       dma_addr = virt_to_dma(dev, ptr);
+
        if (dev->dma_mask) {
+               unsigned long mask = *dev->dma_mask;
                unsigned long limit;
 
-               limit = (*dev->dma_mask + 1) & ~(*dev->dma_mask);
-               if (limit && (size > limit)) {
-                       dev_err(dev, "DMA mapping too big "
-                               "(requested %#x mask %#Lx)\n",
-                               size, *dev->dma_mask);
+               limit = (mask + 1) & ~mask;
+               if (limit && size > limit) {
+                       dev_err(dev, "DMA mapping too big (requested %#x "
+                               "mask %#Lx)\n", size, *dev->dma_mask);
                        return ~0;
                }
-       }
 
-       dma_addr = virt_to_dma(dev, ptr);
+               /*
+                * Figure out if we need to bounce from the DMA mask.
+                */
+               needs_bounce = (dma_addr | (dma_addr + size - 1)) & ~mask;
+       }
 
-       if (device_info && dma_needs_bounce(dev, dma_addr, size)) {
+       if (device_info && (needs_bounce || dma_needs_bounce(dev, dma_addr, size))) {
                struct safe_buffer *buf;
 
                buf = alloc_safe_buffer(device_info, ptr, size, dir);