[PATCH v3 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
da_to_va() + 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. To
cover that usecase don't keep rproc_da_to_va() in
rproc_elf_load_segments() and let the new callback operate on the device
address.

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

The patch only appears big because of indentation changes.

Reviewed-by: Peng Fan <peng.fan@xxxxxxx>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxx>
---
 drivers/remoteproc/remoteproc_elf_loader.c | 64 +++++++++++++---------
 include/linux/remoteproc.h                 |  4 ++
 2 files changed, 41 insertions(+), 27 deletions(-)

diff --git a/drivers/remoteproc/remoteproc_elf_loader.c b/drivers/remoteproc/remoteproc_elf_loader.c
index da3cddbe7d4c..3c749a39e5da 100644
--- a/drivers/remoteproc/remoteproc_elf_loader.c
+++ b/drivers/remoteproc/remoteproc_elf_loader.c
@@ -227,35 +227,45 @@ 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 address 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..e750a127cbc4 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 +100,9 @@ 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