continuing on for size. Again, you *must* observe the cache line
boundaries when doing this.
-::
-
- int
- dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
- dma_addr_t device_addr, size_t size);
-
-Declare region of memory to be handed out by dma_alloc_coherent() when
-it's asked for coherent memory for this device.
-
-phys_addr is the CPU physical address to which the memory is currently
-assigned (this will be ioremapped so the CPU can access the region).
-
-device_addr is the DMA address the device needs to be programmed
-with to actually address this memory (this will be handed out as the
-dma_addr_t in dma_alloc_coherent()).
-
-size is the size of the area (must be multiples of PAGE_SIZE).
-
-As a simplification for the platforms, only *one* such region of
-memory may be declared per device.
-
-For reasons of efficiency, most platforms choose to track the declared
-region only at the granularity of a page. For smaller allocations,
-you should use the dma_pool() API.
Part III - Debug drivers use of the DMA-API
-------------------------------------------
return 0;
}
+/*
+ * Declare a region of memory to be handed out by dma_alloc_coherent() when it
+ * is asked for coherent memory for this device. This shall only be used
+ * from platform code, usually based on the device tree description.
+ *
+ * phys_addr is the CPU physical address to which the memory is currently
+ * assigned (this will be ioremapped so the CPU can access the region).
+ *
+ * device_addr is the DMA address the device needs to be programmed with to
+ * actually address this memory (this will be handed out as the dma_addr_t in
+ * dma_alloc_coherent()).
+ *
+ * size is the size of the area (must be a multiple of PAGE_SIZE).
+ *
+ * As a simplification for the platforms, only *one* such region of memory may
+ * be declared per device.
+ */
int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
dma_addr_t device_addr, size_t size)
{