[PATCH 1/2] remoteproc: elf_loader: Create new callback for copying segments to remote cpu

[Uwe Kleine-König]

Some devices have special needs about how an Elf segment is copied to
the remote cpu's memory space where the default implementation using
memcpy_toio/memcpy and memset_io/memset isn't suitable. An affected
mainline driver is imx-dsp-rproc which includes a near-copy of
rproc_elf_load_segments() just to handle the IRAM only allowing 32 bit
accesses. On (not-yet-mainline) ADI SC846 the respective memory isn't
directly accessible at all and DMA must be used to copy the data.

The new callback can be used to implement just the driver specific
memcpy + memset to increase code reuse.

The patch only appears big because of indentation changes.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxx>
---
 drivers/remoteproc/remoteproc_elf_loader.c | 63 ++++++++++++----------
 include/linux/remoteproc.h                 |  3 ++
 2 files changed, 39 insertions(+), 27 deletions(-)

diff --git a/drivers/remoteproc/remoteproc_elf_loader.c b/drivers/remoteproc/remoteproc_elf_loader.c
index da3cddbe7d4c..0698bba2db89 100644
--- a/drivers/remoteproc/remoteproc_elf_loader.c
+++ b/drivers/remoteproc/remoteproc_elf_loader.c
@@ -227,35 +227,44 @@ int rproc_elf_load_segments(struct rproc *rproc, const struct firmware *fw)
 			break;
 		}
 
-		/* grab the kernel address for this device address */
-		ptr = rproc_da_to_va(rproc, da, memsz, &is_iomem);
-		if (!ptr) {
-			dev_err(dev, "bad phdr da 0x%llx mem 0x%llx\n", da,
-				memsz);
-			ret = -EINVAL;
-			break;
-		}
+		if (rproc->ops->memcpy_tova) {
+			ret = rproc->ops->memcpy_tova(rproc, da, elf_data + offset, filesz, memsz);
+			if (ret) {
+				dev_err(dev, "Failed to copy segment %d to device addres 0x%llx: %pe\n",
+					i, da, ERR_PTR(ret));
+				break;
+			}
+		} else {
+			/* grab the kernel address for this device address */
+			ptr = rproc_da_to_va(rproc, da, memsz, &is_iomem);
+			if (!ptr) {
+				dev_err(dev, "bad phdr da 0x%llx mem 0x%llx\n", da,
+					memsz);
+				ret = -EINVAL;
+				break;
+			}
 
-		/* put the segment where the remote processor expects it */
-		if (filesz) {
-			if (is_iomem)
-				memcpy_toio((void __iomem *)ptr, elf_data + offset, filesz);
-			else
-				memcpy(ptr, elf_data + offset, filesz);
-		}
+			/* put the segment where the remote processor expects it */
+			if (filesz) {
+				if (is_iomem)
+					memcpy_toio((void __iomem *)ptr, elf_data + offset, filesz);
+				else
+					memcpy(ptr, elf_data + offset, filesz);
+			}
 
-		/*
-		 * Zero out remaining memory for this segment.
-		 *
-		 * This isn't strictly required since dma_alloc_coherent already
-		 * did this for us. albeit harmless, we may consider removing
-		 * this.
-		 */
-		if (memsz > filesz) {
-			if (is_iomem)
-				memset_io((void __iomem *)(ptr + filesz), 0, memsz - filesz);
-			else
-				memset(ptr + filesz, 0, memsz - filesz);
+			/*
+			 * Zero out remaining memory for this segment.
+			 *
+			 * This isn't strictly required since dma_alloc_coherent already
+			 * did this for us. albeit harmless, we may consider removing
+			 * this.
+			 */
+			if (memsz > filesz) {
+				if (is_iomem)
+					memset_io((void __iomem *)(ptr + filesz), 0, memsz - filesz);
+				else
+					memset(ptr + filesz, 0, memsz - filesz);
+			}
 		}
 	}
 
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index 00019b1895e6..ffa22c2f04af 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -75,6 +75,7 @@ enum rsc_handling_status {
  * @detach:	detach from a device, leaving it powered up
  * @kick:	kick a virtqueue (virtqueue id given as a parameter)
  * @da_to_va:	optional platform hook to perform address translations
+ * @memcpy_tova:optional platform hook to copy data into remote memory range
  * @parse_fw:	parse firmware to extract information (e.g. resource table)
  * @handle_rsc:	optional platform hook to handle vendor resources. Should return
  *		RSC_HANDLED if resource was handled, RSC_IGNORED if not handled
@@ -99,6 +100,8 @@ struct rproc_ops {
 	int (*detach)(struct rproc *rproc);
 	void (*kick)(struct rproc *rproc, int vqid);
 	void * (*da_to_va)(struct rproc *rproc, u64 da, size_t len, bool *is_iomem);
+	int (*memcpy_tova)(struct rproc *rproc, u64 da, const void *src, size_t filesz, size_t memsz);
+
 	int (*parse_fw)(struct rproc *rproc, const struct firmware *fw);
 	int (*handle_rsc)(struct rproc *rproc, u32 rsc_type, void *rsc,
 			  int offset, int avail);
-- 
2.47.3