Merge remote-tracking branch 'wq/for-7.1-devm-alloc-wq'

Merge branch adding support for device-managed workqueue allocation,
which allows cleaning up a chrome-platform driver.

Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>

Author: Tzung-Bi Shih

Documentation/driver-api/driver-model/devres.rst

@@ -464,3 +464,7 @@ SPI
 
 WATCHDOG
   devm_watchdog_register_device()
+
+WORKQUEUE
+  devm_alloc_workqueue()
+  devm_alloc_ordered_workqueue()

include/linux/workqueue.h

@@ -512,6 +512,26 @@ __printf(1, 4) struct workqueue_struct *
 alloc_workqueue_noprof(const char *fmt, unsigned int flags, int max_active, ...);
 #define alloc_workqueue(...)	alloc_hooks(alloc_workqueue_noprof(__VA_ARGS__))
 
+/**
+ * devm_alloc_workqueue - Resource-managed allocate a workqueue
+ * @dev: Device to allocate workqueue for
+ * @fmt: printf format for the name of the workqueue
+ * @flags: WQ_* flags
+ * @max_active: max in-flight work items, 0 for default
+ * @...: args for @fmt
+ *
+ * Resource managed workqueue, see alloc_workqueue() for details.
+ *
+ * The workqueue will be automatically destroyed on driver detach.  Typically
+ * this should be used in drivers already relying on devm interafaces.
+ *
+ * RETURNS:
+ * Pointer to the allocated workqueue on success, %NULL on failure.
+ */
+__printf(2, 5) struct workqueue_struct *
+devm_alloc_workqueue(struct device *dev, const char *fmt, unsigned int flags,
+		     int max_active, ...);
+
 #ifdef CONFIG_LOCKDEP
 /**
  * alloc_workqueue_lockdep_map - allocate a workqueue with user-defined lockdep_map
@@ -568,6 +588,8 @@ alloc_workqueue_lockdep_map(const char *fmt, unsigned int flags, int max_active,
  */
 #define alloc_ordered_workqueue(fmt, flags, args...)			\
 	alloc_workqueue(fmt, WQ_UNBOUND | __WQ_ORDERED | (flags), 1, ##args)
+#define devm_alloc_ordered_workqueue(dev, fmt, flags, args...)		\
+	devm_alloc_workqueue(dev, fmt, WQ_UNBOUND | __WQ_ORDERED | (flags), 1, ##args)
 
 #define create_workqueue(name)						\
 	alloc_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_PERCPU, 1, (name))

kernel/workqueue.c

@@ -41,6 +41,7 @@
 #include <linux/mempolicy.h>
 #include <linux/freezer.h>
 #include <linux/debug_locks.h>
+#include <linux/device/devres.h>
 #include <linux/lockdep.h>
 #include <linux/idr.h>
 #include <linux/jhash.h>
@@ -5891,6 +5892,33 @@ struct workqueue_struct *alloc_workqueue_noprof(const char *fmt,
 }
 EXPORT_SYMBOL_GPL(alloc_workqueue_noprof);
 
+static void devm_workqueue_release(void *res)
+{
+	destroy_workqueue(res);
+}
+
+__printf(2, 5) struct workqueue_struct *
+devm_alloc_workqueue(struct device *dev, const char *fmt, unsigned int flags,
+		     int max_active, ...)
+{
+	struct workqueue_struct *wq;
+	va_list args;
+	int ret;
+
+	va_start(args, max_active);
+	wq = alloc_workqueue(fmt, flags, max_active, args);
+	va_end(args);
+	if (!wq)
+		return NULL;
+
+	ret = devm_add_action_or_reset(dev, devm_workqueue_release, wq);
+	if (ret)
+		return NULL;
+
+	return wq;
+}
+EXPORT_SYMBOL_GPL(devm_alloc_workqueue);
+
 #ifdef CONFIG_LOCKDEP
 __printf(1, 5)
 struct workqueue_struct *