[PATCH v2 1/2] remoteproc: core: Add an API for changing firmware name

[Siddharth Gupta <sidgup@codeaurora.org>]

Add an API which allows to change the name of the firmware to be booted on
the specified rproc. This change gives us the flixibility to change the
firmware at run-time depending on the usecase. Some remoteprocs might use
a different firmware for testing, production and development purposes,
which may be selected based on the fuse settings during bootup.

Signed-off-by: Siddharth Gupta <sidgup@codeaurora.org>
---
 drivers/remoteproc/remoteproc_core.c | 43 ++++++++++++++++++++++++++++++++++++
 include/linux/remoteproc.h           |  1 +
 2 files changed, 44 insertions(+)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index fb9c813..9f99fe2 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -1796,6 +1796,49 @@ int rproc_boot(struct rproc *rproc)
 EXPORT_SYMBOL(rproc_boot);
 
 /**
+ * rproc_set_firmware_name() - change the firmware name for specified remoteproc
+ * @rproc: handle of a remote processor
+ * @firmware: name of the firmware to boot with
+ *
+ * Change the name of the firmware to be loaded to @firmware in the rproc
+ * structure. We should ensure that the remoteproc is not running.
+ *
+ * Returns 0 on success, and an appropriate error value otherwise.
+ */
+int rproc_set_firmware_name(struct rproc *rproc, const char *firmware)
+{
+	int len, ret = 0;
+	char *p;
+
+	if (!rproc || !firmware)
+		return -EINVAL;
+
+	len = strcspn(firmware, "\n");
+	if (!len)
+		return -EINVAL;
+
+	mutex_lock(&rproc->lock);
+
+	if (rproc->state != RPROC_OFFLINE) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	p = kstrndup(firmware, len, GFP_KERNEL);
+	if (!p) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	kfree(rproc->firmware);
+	rproc->firmware = p;
+out:
+	mutex_unlock(&rproc->lock);
+	return ret;
+}
+EXPORT_SYMBOL(rproc_set_firmware_name);
+
+/**
  * rproc_shutdown() - power off the remote processor
  * @rproc: the remote processor
  *
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index 9c07d79..c5d36e6 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -613,6 +613,7 @@ rproc_of_resm_mem_entry_init(struct device *dev, u32 of_resm_idx, size_t len,
 			     u32 da, const char *name, ...);
 
 int rproc_boot(struct rproc *rproc);
+int rproc_set_firmware_name(struct rproc *rproc, const char *firmware);
 void rproc_shutdown(struct rproc *rproc);
 void rproc_report_crash(struct rproc *rproc, enum rproc_crash_type type);
 int rproc_coredump_add_segment(struct rproc *rproc, dma_addr_t da, size_t size);
-- 
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