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path: root/drivers/scsi/scsi_lib.c
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Diffstat (limited to 'drivers/scsi/scsi_lib.c')
-rw-r--r--drivers/scsi/scsi_lib.c59
1 files changed, 59 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 4a602853a98..4362dcde74a 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -16,6 +16,7 @@
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/delay.h>
+#include <linux/hardirq.h>
#include <scsi/scsi.h>
#include <scsi/scsi_dbg.h>
@@ -2248,3 +2249,61 @@ scsi_target_unblock(struct device *dev)
device_for_each_child(dev, NULL, target_unblock);
}
EXPORT_SYMBOL_GPL(scsi_target_unblock);
+
+
+struct work_queue_work {
+ struct work_struct work;
+ void (*fn)(void *);
+ void *data;
+};
+
+static void execute_in_process_context_work(void *data)
+{
+ void (*fn)(void *data);
+ struct work_queue_work *wqw = data;
+
+ fn = wqw->fn;
+ data = wqw->data;
+
+ kfree(wqw);
+
+ fn(data);
+}
+
+/**
+ * scsi_execute_in_process_context - reliably execute the routine with user context
+ * @fn: the function to execute
+ * @data: data to pass to the function
+ *
+ * Executes the function immediately if process context is available,
+ * otherwise schedules the function for delayed execution.
+ *
+ * Returns: 0 - function was executed
+ * 1 - function was scheduled for execution
+ * <0 - error
+ */
+int scsi_execute_in_process_context(void (*fn)(void *data), void *data)
+{
+ struct work_queue_work *wqw;
+
+ if (!in_interrupt()) {
+ fn(data);
+ return 0;
+ }
+
+ wqw = kmalloc(sizeof(struct work_queue_work), GFP_ATOMIC);
+
+ if (unlikely(!wqw)) {
+ printk(KERN_ERR "Failed to allocate memory\n");
+ WARN_ON(1);
+ return -ENOMEM;
+ }
+
+ INIT_WORK(&wqw->work, execute_in_process_context_work, wqw);
+ wqw->fn = fn;
+ wqw->data = data;
+ schedule_work(&wqw->work);
+
+ return 1;
+}
+EXPORT_SYMBOL_GPL(scsi_execute_in_process_context);