net: davinci_cpdma: use dma_addr_t for DMA address

The davinci_cpdma mixes up physical addresses as seen from the CPU
and DMA addresses as seen from a DMA master, since it can operate
on both normal memory or an on-chip buffer. If dma_addr_t is
different from phys_addr_t, this means we get a compile-time warning
about the type mismatch:

ethernet/ti/davinci_cpdma.c: In function 'cpdma_desc_pool_create':
ethernet/ti/davinci_cpdma.c:182:48: error: passing argument 3 of 'dma_alloc_coherent' from incompatible pointer type [-Werror=incompatible-pointer-types]
   pool->cpumap = dma_alloc_coherent(dev, size, &pool->phys,
In file included from ethernet/ti/davinci_cpdma.c:21:0:
dma-mapping.h:398:21: note: expected 'dma_addr_t * {aka long long unsigned int *}' but argument is of type 'phys_addr_t * {aka unsigned int *}'
 static inline void *dma_alloc_coherent(struct device *dev, size_t size,

This slightly restructures the code so the address we use for
mapping RAM into a DMA address is always a dma_addr_t, avoiding
the warning. The code is correct even if both types are 32-bit
because the DMA master in this device only supports 32-bit addressing
anyway, independent of the types that are used.

We still assign this value to pool->phys, and that is wrong if
the driver is ever used with an IOMMU, but that value appears to
be never used, so there is no problem really. I've added a couple
of comments about where we do things that are slightly violating
the API.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/ti/davinci_cpdma.c b/drivers/net/ethernet/ti/davinci_cpdma.c
index 657b65bf5cac64254b4db7c845038d2e40549a8c..18bf3a8fdc505ad2ed8a0fa3b81dfeb7d833b94d 100644 (file)
--- a/drivers/net/ethernet/ti/davinci_cpdma.c
+++ b/drivers/net/ethernet/ti/davinci_cpdma.c
@@ -82,7 +82,7 @@ struct cpdma_desc {
 
 struct cpdma_desc_pool {
        phys_addr_t             phys;
-       u32                     hw_addr;
+       dma_addr_t              hw_addr;
        void __iomem            *iomap;         /* ioremap map */
        void                    *cpumap;        /* dma_alloc map */
        int                     desc_size, mem_size;
@@ -152,7 +152,7 @@ struct cpdma_chan {
  * abstract out these details
  */
 static struct cpdma_desc_pool *
-cpdma_desc_pool_create(struct device *dev, u32 phys, u32 hw_addr,
+cpdma_desc_pool_create(struct device *dev, u32 phys, dma_addr_t hw_addr,
                                int size, int align)
 {
        int bitmap_size;
@@ -176,13 +176,13 @@ cpdma_desc_pool_create(struct device *dev, u32 phys, u32 hw_addr,
 
        if (phys) {
                pool->phys  = phys;
-               pool->iomap = ioremap(phys, size);
+               pool->iomap = ioremap(phys, size); /* should be memremap? */
                pool->hw_addr = hw_addr;
        } else {
-               pool->cpumap = dma_alloc_coherent(dev, size, &pool->phys,
+               pool->cpumap = dma_alloc_coherent(dev, size, &pool->hw_addr,
                                                  GFP_KERNEL);
-               pool->iomap = pool->cpumap;
-               pool->hw_addr = pool->phys;
+               pool->iomap = (void __iomem __force *)pool->cpumap;
+               pool->phys = pool->hw_addr; /* assumes no IOMMU, don't use this value */
        }
 
        if (pool->iomap)