[PATCH v22 4/7] remoteproc: Introduce optional release_fw operation

[Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>]

The release_fw operation allows releasing remote processor resources
configured during rproc_parse_fw() and rproc_load_segments().
For example, it can release carveouts mapped during these operations.

This operation is invoked in the following cases:
 - When an error occurs during remote processor boot.
 - When an error occurs during remote processor recovery start.
 - After stopping the remote processor.

This operation is required for the remoteproc_tee implementation following
a stop or upon encountering an error. Since the remoteproc image is loaded
during resource table parsing, multiple failure scenarios may occur prior
to remote processor startup, including issues with resource handling and
carveout allocation.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>

---

Updates from version 18:
- Rewrite rproc_ops::release_fw documentation
- Improve commit message

Updates from version 16:
- Removed the rproc:load_fw() ops introduced in previous version.
- Removed duplicate calls to rproc_release_fw in rproc_fw_boot and rproc_boot.
---
 drivers/remoteproc/remoteproc_core.c     | 6 ++++++
 drivers/remoteproc/remoteproc_internal.h | 6 ++++++
 include/linux/remoteproc.h               | 5 +++++
 3 files changed, 17 insertions(+)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index ec1860e1cfa9..93ab505ff014 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -1856,6 +1856,8 @@ static int rproc_boot_recovery(struct rproc *rproc)
 
 	/* boot the remote processor up again */
 	ret = rproc_start(rproc, firmware_p);
+	if (ret)
+		rproc_release_fw(rproc);
 
 	release_firmware(firmware_p);
 
@@ -1997,6 +1999,8 @@ int rproc_boot(struct rproc *rproc)
 		}
 
 		ret = rproc_fw_boot(rproc, firmware_p);
+		if (ret)
+			rproc_release_fw(rproc);
 
 		release_firmware(firmware_p);
 	}
@@ -2066,6 +2070,8 @@ int rproc_shutdown(struct rproc *rproc)
 
 	rproc_disable_iommu(rproc);
 
+	rproc_release_fw(rproc);
+
 	/* Free the copy of the resource table */
 	kfree(rproc->cached_table);
 	rproc->cached_table = NULL;
diff --git a/drivers/remoteproc/remoteproc_internal.h b/drivers/remoteproc/remoteproc_internal.h
index 0cd09e67ac14..c7fb908f8652 100644
--- a/drivers/remoteproc/remoteproc_internal.h
+++ b/drivers/remoteproc/remoteproc_internal.h
@@ -221,4 +221,10 @@ bool rproc_u64_fit_in_size_t(u64 val)
 	return (val <= (size_t) -1);
 }
 
+static inline void rproc_release_fw(struct rproc *rproc)
+{
+	if (rproc->ops->release_fw)
+		rproc->ops->release_fw(rproc);
+}
+
 #endif /* REMOTEPROC_INTERNAL_H */
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index 8fd0d7f63c8e..a2bb51a113b1 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -381,6 +381,10 @@ enum rsc_handling_status {
  * @panic:	optional callback to react to system panic, core will delay
  *		panic at least the returned number of milliseconds
  * @coredump:	  collect firmware dump after the subsystem is shutdown
+ * @release_fw:	Optional function to release resources allocated during
+ *		parse_fw() or load() operations. This function is called after
+ *		stopping the remote processor or in case of an error during the
+ *		boot or recovery sequence.
  */
 struct rproc_ops {
 	int (*prepare)(struct rproc *rproc);
@@ -403,6 +407,7 @@ struct rproc_ops {
 	u64 (*get_boot_addr)(struct rproc *rproc, const struct firmware *fw);
 	unsigned long (*panic)(struct rproc *rproc);
 	void (*coredump)(struct rproc *rproc);
+	void (*release_fw)(struct rproc *rproc);
 };
 
 /**
-- 
2.43.0