remoteproc: Add a rproc_set_firmware() API

A new API, rproc_set_firmware() is added to allow the remoteproc platform
drivers and remoteproc client drivers to be able to configure a custom
firmware name that is different from the default name used during
remoteproc registration. This function is being introduced to provide
a kernel-level equivalent of the current sysfs interface to remoteproc
client drivers, and can only change firmwares when the remoteproc is
offline. This allows some remoteproc drivers to choose different firmwares
at runtime based on the functionality the remote processor is providing.
The TI PRU Ethernet driver will be an example of such usage as it
requires to use different firmwares for different supported protocols.

Also, update the firmware_store() function used by the sysfs interface
to reuse this function to avoid code duplication.

Signed-off-by: Suman Anna <s-anna@ti.com>

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index 6df156f80c7c32b88dea88240aa1fa5726318267..0503b7f61897741808963172543ceaa501318e37 100644 (file)
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -1878,6 +1878,69 @@ void rproc_report_crash(struct rproc *rproc, enum rproc_crash_type type)
 }
 EXPORT_SYMBOL(rproc_report_crash);
 
+/**
+ * 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.
+ *
+ * Returns 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 __init remoteproc_init(void)
 {
        rproc_init_sysfs();

diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c
index 97e41f9d60de74b7c278fedf5ef95498fe35873f..184c899b7a0d163283fce3158ce061c4aab92400 100644 (file)
--- a/drivers/remoteproc/remoteproc_sysfs.c
+++ b/drivers/remoteproc/remoteproc_sysfs.c
@@ -32,42 +32,13 @@ 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;
 
        /* restrict sysfs operations if not allowed by remoteproc drivers */
        if (rproc->deny_sysfs_ops)
                return -EPERM;
 
-       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 32c16cef928d1d6fca6ca38c51a4580efb296ad7..e78b6e5d0886adaa54e2f1455b87f89d72e6a7ad 100644 (file)
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -564,6 +564,7 @@ void rproc_free(struct rproc *rproc);
 
 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_get_id(struct rproc *rproc);