remoteproc: Refactor rproc module locking

Lock the implementation as we hand out references to client drivers
rather than when they try to boot the remote processor. This allows
auto-booting remote processors to be shut down by unloading their
module, in addition to first unbinding them.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

1 files changed, 8 insertions, 12 deletions

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index ede3af14b9d0..c6bfb3496684 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -1035,13 +1035,6 @@ static int __rproc_boot(struct rproc *rproc, bool wait)
                 return ret;
         }
 
-        /* prevent underlying implementation from being removed */
-        if (!try_module_get(dev->parent->driver->owner)) {
-                dev_err(dev, "%s: can't get owner\n", __func__);
-                ret = -EINVAL;
-                goto unlock_mutex;
-        }
-
         /* skip the boot process if rproc is already powered up */
         if (atomic_inc_return(&rproc->power) > 1) {
                 ret = 0;
@@ -1066,10 +1059,8 @@ static int __rproc_boot(struct rproc *rproc, bool wait)
         release_firmware(firmware_p);
 
 downref_rproc:
-        if (ret) {
-                module_put(dev->parent->driver->owner);
+        if (ret)
                 atomic_dec(&rproc->power);
-        }
 unlock_mutex:
         mutex_unlock(&rproc->lock);
         return ret;
@@ -1158,8 +1149,6 @@ void rproc_shutdown(struct rproc *rproc)
 
 out:
         mutex_unlock(&rproc->lock);
-        if (!ret)
-                module_put(dev->parent->driver->owner);
 }
 EXPORT_SYMBOL(rproc_shutdown);
 
@@ -1188,6 +1177,12 @@ struct rproc *rproc_get_by_phandle(phandle phandle)
         mutex_lock(&rproc_list_mutex);
         list_for_each_entry(r, &rproc_list, node) {
                 if (r->dev.parent && r->dev.parent->of_node == np) {
+                        /* prevent underlying implementation from being removed */
+                        if (!try_module_get(r->dev.parent->driver->owner)) {
+                                dev_err(&r->dev, "can't get owner\n");
+                                break;
+                        }
+
                         rproc = r;
                         get_device(&rproc->dev);
                         break;
@@ -1411,6 +1406,7 @@ EXPORT_SYMBOL(rproc_free);
  */
 void rproc_put(struct rproc *rproc)
 {
+        module_put(rproc->dev.parent->driver->owner);
         put_device(&rproc->dev);
 }
 EXPORT_SYMBOL(rproc_put);