omap: mailbox: OMAP4 Mailbox-driver Patch to support tasklet implementation

This patch uses a tasklet implementation for
sending mailbox messages.

Signed-off-by: C A Subramaniam <subramaniam.ca@ti.com>
Signed-off-by: Ramesh Gupta G <grgupta@ti.com>
Signed-off-by: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

2 files changed, 23 insertions, 44 deletions

diff --git a/arch/arm/plat-omap/include/plat/mailbox.h b/arch/arm/plat-omap/include/plat/mailbox.h
index bf0695310bde..729166b76a7c 100644
--- a/arch/arm/plat-omap/include/plat/mailbox.h
+++ b/arch/arm/plat-omap/include/plat/mailbox.h
@@ -6,6 +6,7 @@
 #include <linux/wait.h>
 #include <linux/workqueue.h>
 #include <linux/blkdev.h>
+#include <linux/interrupt.h>
 
 typedef u32 mbox_msg_t;
 struct omap_mbox;
@@ -28,8 +29,10 @@ struct omap_mbox_ops {
         int             (*fifo_empty)(struct omap_mbox *mbox);
         int             (*fifo_full)(struct omap_mbox *mbox);
         /* irq */
-        void            (*enable_irq)(struct omap_mbox *mbox, omap_mbox_irq_t irq);
-        void            (*disable_irq)(struct omap_mbox *mbox, omap_mbox_irq_t irq);
+        void            (*enable_irq)(struct omap_mbox *mbox,
+                                                omap_mbox_irq_t irq);
+        void            (*disable_irq)(struct omap_mbox *mbox,
+                                                omap_mbox_irq_t irq);
         void            (*ack_irq)(struct omap_mbox *mbox, omap_mbox_irq_t irq);
         int             (*is_irq)(struct omap_mbox *mbox, omap_mbox_irq_t irq);
         /* ctx */
@@ -41,6 +44,7 @@ struct omap_mbox_queue {
         spinlock_t              lock;
         struct request_queue    *queue;
         struct work_struct      work;
+        struct tasklet_struct   tasklet;
         int     (*callback)(void *);
         struct omap_mbox        *mbox;
 };
diff --git a/arch/arm/plat-omap/mailbox.c b/arch/arm/plat-omap/mailbox.c
index 4d7947e5dd95..8e90633e4cb9 100644
--- a/arch/arm/plat-omap/mailbox.c
+++ b/arch/arm/plat-omap/mailbox.c
@@ -80,74 +80,45 @@ static int __mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg)
         return ret;
 }
 
-struct omap_msg_tx_data {
-        mbox_msg_t      msg;
-};
-
-static void omap_msg_tx_end_io(struct request *rq, int error)
-{
-        kfree(rq->special);
-        __blk_put_request(rq->q, rq);
-}
 
 int omap_mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg)
 {
-        struct omap_msg_tx_data *tx_data;
+
         struct request *rq;
         struct request_queue *q = mbox->txq->queue;
 
-        tx_data = kmalloc(sizeof(*tx_data), GFP_ATOMIC);
-        if (unlikely(!tx_data))
-                return -ENOMEM;
-
         rq = blk_get_request(q, WRITE, GFP_ATOMIC);
-        if (unlikely(!rq)) {
-                kfree(tx_data);
+        if (unlikely(!rq))
                 return -ENOMEM;
-        }
 
-        tx_data->msg = msg;
-        rq->end_io = omap_msg_tx_end_io;
-        blk_insert_request(q, rq, 0, tx_data);
+        blk_insert_request(q, rq, 0, (void *) msg);
+        tasklet_schedule(&mbox->txq->tasklet);
 
-        schedule_work(&mbox->txq->work);
         return 0;
 }
 EXPORT_SYMBOL(omap_mbox_msg_send);
 
-static void mbox_tx_work(struct work_struct *work)
+static void mbox_tx_tasklet(unsigned long tx_data)
 {
         int ret;
         struct request *rq;
-        struct omap_mbox_queue *mq = container_of(work,
-                                struct omap_mbox_queue, work);
-        struct omap_mbox *mbox = mq->queue->queuedata;
+        struct omap_mbox *mbox = (struct omap_mbox *)tx_data;
         struct request_queue *q = mbox->txq->queue;
 
         while (1) {
-                struct omap_msg_tx_data *tx_data;
 
-                spin_lock(q->queue_lock);
                 rq = blk_fetch_request(q);
-                spin_unlock(q->queue_lock);
 
                 if (!rq)
                         break;
 
-                tx_data = rq->special;
-
-                ret = __mbox_msg_send(mbox, tx_data->msg);
+                ret = __mbox_msg_send(mbox, (mbox_msg_t)rq->special);
                 if (ret) {
                         omap_mbox_enable_irq(mbox, IRQ_TX);
-                        spin_lock(q->queue_lock);
                         blk_requeue_request(q, rq);
-                        spin_unlock(q->queue_lock);
                         return;
                 }
-
-                spin_lock(q->queue_lock);
-                __blk_end_request_all(rq, 0);
-                spin_unlock(q->queue_lock);
+                blk_end_request_all(rq, 0);
         }
 }
 
@@ -192,7 +163,7 @@ static void __mbox_tx_interrupt(struct omap_mbox *mbox)
 {
         omap_mbox_disable_irq(mbox, IRQ_TX);
         ack_mbox_irq(mbox, IRQ_TX);
-        schedule_work(&mbox->txq->work);
+        tasklet_schedule(&mbox->txq->tasklet);
 }
 
 static void __mbox_rx_interrupt(struct omap_mbox *mbox)
@@ -235,7 +206,8 @@ static irqreturn_t mbox_interrupt(int irq, void *p)
 
 static struct omap_mbox_queue *mbox_queue_alloc(struct omap_mbox *mbox,
                                         request_fn_proc *proc,
-                                        void (*work) (struct work_struct *))
+                                        void (*work) (struct work_struct *),
+                                        void (*tasklet)(unsigned long))
 {
         struct request_queue *q;
         struct omap_mbox_queue *mq;
@@ -252,8 +224,11 @@ static struct omap_mbox_queue *mbox_queue_alloc(struct omap_mbox *mbox,
         q->queuedata = mbox;
         mq->queue = q;
 
-        INIT_WORK(&mq->work, work);
+        if (work)
+                INIT_WORK(&mq->work, work);
 
+        if (tasklet)
+                tasklet_init(&mq->tasklet, tasklet, (unsigned long)mbox);
         return mq;
 error:
         kfree(mq);
@@ -292,14 +267,14 @@ static int omap_mbox_startup(struct omap_mbox *mbox)
                 goto fail_request_irq;
         }
 
-        mq = mbox_queue_alloc(mbox, mbox_txq_fn, mbox_tx_work);
+        mq = mbox_queue_alloc(mbox, mbox_txq_fn, NULL, mbox_tx_tasklet);
         if (!mq) {
                 ret = -ENOMEM;
                 goto fail_alloc_txq;
         }
         mbox->txq = mq;
 
-        mq = mbox_queue_alloc(mbox, mbox_rxq_fn, mbox_rx_work);
+        mq = mbox_queue_alloc(mbox, mbox_rxq_fn, mbox_rx_work, NULL);
         if (!mq) {
                 ret = -ENOMEM;
                 goto fail_alloc_rxq;