remoteproc: mtk_scp: use dma_addr_t for DMA API

dma_addr_t and phys_addr_t are distinct types and must not be
mixed, as both the values and the size of the type may be
different depending on what the remote device uses.

In this driver the compiler warns when the two types are different:

drivers/remoteproc/mtk_scp.c: In function 'scp_map_memory_region':
drivers/remoteproc/mtk_scp.c:454:9: error: passing argument 3 of 'dma_alloc_coherent' from incompatible pointer type [-Werror=incompatible-pointer-types]
  454 |         &scp->phys_addr, GFP_KERNEL);
      |         ^~~~~~~~~~~~~~~
      |         |
      |         phys_addr_t * {aka unsigned int *}
In file included from drivers/remoteproc/mtk_scp.c:7:
include/linux/dma-mapping.h:642:15: note: expected 'dma_addr_t *' {aka 'long long unsigned int *'} but argument is of type 'phys_addr_t *' {aka 'unsigned int *'}
  642 |   dma_addr_t *dma_handle, gfp_t gfp)

Change the phys_addr member to be typed and named according
to how it is allocated.

Fixes: 63c13d61 ("remoteproc/mediatek: add SCP support for mt8183")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20200408155450.2186471-1-arnd@arndb.deSigned-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

drivers/remoteproc/mtk_common.h

@@ -68,7 +68,7 @@ struct mtk_scp {
 	wait_queue_head_t ack_wq;
 
 	void __iomem *cpu_addr;
-	phys_addr_t phys_addr;
+	dma_addr_t dma_addr;
 	size_t dram_size;
 
 	struct rproc_subdev *rpmsg_subdev;

drivers/remoteproc/mtk_scp.c

@@ -330,7 +330,7 @@ static void *scp_da_to_va(struct rproc *rproc, u64 da, size_t len)
 		if (offset >= 0 && (offset + len) < scp->sram_size)
 			return (void __force *)scp->sram_base + offset;
 	} else {
-		offset = da - scp->phys_addr;
+		offset = da - scp->dma_addr;
 		if (offset >= 0 && (offset + len) < scp->dram_size)
 			return (void __force *)scp->cpu_addr + offset;
 	}
@@ -451,7 +451,7 @@ static int scp_map_memory_region(struct mtk_scp *scp)
 	/* Reserved SCP code size */
 	scp->dram_size = MAX_CODE_SIZE;
 	scp->cpu_addr = dma_alloc_coherent(scp->dev, scp->dram_size,
-					   &scp->phys_addr, GFP_KERNEL);
+					   &scp->dma_addr, GFP_KERNEL);
 	if (!scp->cpu_addr)
 		return -ENOMEM;
 
@@ -461,7 +461,7 @@ static int scp_map_memory_region(struct mtk_scp *scp)
 static void scp_unmap_memory_region(struct mtk_scp *scp)
 {
 	dma_free_coherent(scp->dev, scp->dram_size, scp->cpu_addr,
-			  scp->phys_addr);
+			  scp->dma_addr);
 	of_reserved_mem_device_release(scp->dev);
 }