3 files changed, 66 insertions, 31 deletions

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index dab2c0f5caf0..46c2937ebea9 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -1934,6 +1934,69 @@ struct rproc *rproc_get_by_phandle(phandle phandle)
 #endif
 EXPORT_SYMBOL(rproc_get_by_phandle);
 
+/**
+ * rproc_set_firmware() - assign a new firmware
+ * @rproc: rproc handle to which the new firmware is being assigned
+ * @fw_name: new firmware name to be assigned
+ *
+ * This function allows remoteproc drivers or clients to configure a custom
+ * firmware name that is different from the default name used during remoteproc
+ * registration. The function does not trigger a remote processor boot,
+ * only sets the firmware name used for a subsequent boot. This function
+ * should also be called only when the remote processor is offline.
+ *
+ * This allows either the userspace to configure a different name through
+ * sysfs or a kernel-level remoteproc or a remoteproc client driver to set
+ * a specific firmware when it is controlling the boot and shutdown of the
+ * remote processor.
+ *
+ * Return: 0 on success or a negative value upon failure
+ */
+int rproc_set_firmware(struct rproc *rproc, const char *fw_name)
+{
+	struct device *dev;
+	int ret, len;
+	char *p;
+
+	if (!rproc || !fw_name)
+		return -EINVAL;
+
+	dev = rproc->dev.parent;
+
+	ret = mutex_lock_interruptible(&rproc->lock);
+	if (ret) {
+		dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, ret);
+		return -EINVAL;
+	}
+
+	if (rproc->state != RPROC_OFFLINE) {
+		dev_err(dev, "can't change firmware while running\n");
+		ret = -EBUSY;
+		goto out;
+	}
+
+	len = strcspn(fw_name, "\n");
+	if (!len) {
+		dev_err(dev, "can't provide empty string for firmware name\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	p = kstrndup(fw_name, 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);
+
 static int rproc_validate(struct rproc *rproc)
 {
 	switch (rproc->state) {
diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c
index d1cf7bf277c4..1dbef895e65e 100644
--- a/drivers/remoteproc/remoteproc_sysfs.c
+++ b/drivers/remoteproc/remoteproc_sysfs.c
@@ -154,38 +154,9 @@ static ssize_t firmware_store(struct device *dev,
 			      const char *buf, size_t count)
 {
 	struct rproc *rproc = to_rproc(dev);
-	char *p;
-	int err, len = count;
+	int err;
 
-	err = mutex_lock_interruptible(&rproc->lock);
-	if (err) {
-		dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, err);
-		return -EINVAL;
-	}
-
-	if (rproc->state != RPROC_OFFLINE) {
-		dev_err(dev, "can't change firmware while running\n");
-		err = -EBUSY;
-		goto out;
-	}
-
-	len = strcspn(buf, "\n");
-	if (!len) {
-		dev_err(dev, "can't provide a NULL firmware\n");
-		err = -EINVAL;
-		goto out;
-	}
-
-	p = kstrndup(buf, len, GFP_KERNEL);
-	if (!p) {
-		err = -ENOMEM;
-		goto out;
-	}
-
-	kfree(rproc->firmware);
-	rproc->firmware = p;
-out:
-	mutex_unlock(&rproc->lock);
+	err = rproc_set_firmware(rproc, buf);
 
 	return err ? err : count;
 }
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index 3fa3ba6498e8..e8ac041c64d9 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -653,6 +653,7 @@ rproc_of_resm_mem_entry_init(struct device *dev, u32 of_resm_idx, size_t len,
 
 int rproc_boot(struct rproc *rproc);
 void rproc_shutdown(struct rproc *rproc);
+int rproc_set_firmware(struct rproc *rproc, const char *fw_name);
 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);
 int rproc_coredump_add_custom_segment(struct rproc *rproc,