arm-omap: don't abuse rq->data

omap mailbox uses rq->data as the second opaque pointer to carry
mbox_msg_t and rq->special message argument which is needed only for
tx.  Add and use omap_msg_tx_data struct for tx and use rq->special
for mbox_msg_t for rx such that only rq->special is used as opaque
pointer.

[ Impact: cleanup rq->data usage, extra kmalloc in msg_send ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>

diff --git a/arch/arm/plat-omap/mailbox.c b/arch/arm/plat-omap/mailbox.c
index cf81bad..538ba75 100644 (file)
--- a/arch/arm/plat-omap/mailbox.c
+++ b/arch/arm/plat-omap/mailbox.c
@@ -147,24 +147,40 @@ static int __mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg, void *arg)
        return ret;
 }
 
+struct omap_msg_tx_data {
+       mbox_msg_t      msg;
+       void            *arg;
+};
+
+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, void* arg)
 {
+       struct omap_msg_tx_data *tx_data;
        struct request *rq;
        struct request_queue *q = mbox->txq->queue;
-       int ret = 0;
+
+       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)) {
-               ret = -ENOMEM;
-               goto fail;
+               kfree(tx_data);
+               return -ENOMEM;
        }
 
-       rq->data = (void *)msg;
-       blk_insert_request(q, rq, 0, arg);
+       tx_data->msg = msg;
+       tx_data->arg = arg;
+       rq->end_io = omap_msg_tx_end_io;
+       blk_insert_request(q, rq, 0, tx_data);
 
        schedule_work(&mbox->txq->work);
- fail:
-       return ret;
+       return 0;
 }
 EXPORT_SYMBOL(omap_mbox_msg_send);
 
@@ -178,6 +194,8 @@ static void mbox_tx_work(struct work_struct *work)
        struct request_queue *q = mbox->txq->queue;
 
        while (1) {
+               struct omap_msg_tx_data *tx_data;
+
                spin_lock(q->queue_lock);
                rq = elv_next_request(q);
                spin_unlock(q->queue_lock);
@@ -185,7 +203,9 @@ static void mbox_tx_work(struct work_struct *work)
                if (!rq)
                        break;
 
-               ret = __mbox_msg_send(mbox, (mbox_msg_t) rq->data, rq->special);
+               tx_data = rq->special;
+
+               ret = __mbox_msg_send(mbox, tx_data->msg, tx_data->arg);
                if (ret) {
                        enable_mbox_irq(mbox, IRQ_TX);
                        return;
@@ -222,7 +242,7 @@ static void mbox_rx_work(struct work_struct *work)
                if (!rq)
                        break;
 
-               msg = (mbox_msg_t) rq->data;
+               msg = (mbox_msg_t)rq->special;
                blk_end_request_all(rq, 0);
                mbox->rxq->callback((void *)msg);
        }
@@ -260,7 +280,6 @@ static void __mbox_rx_interrupt(struct omap_mbox *mbox)
                        goto nomem;
 
                msg = mbox_fifo_read(mbox);
-               rq->data = (void *)msg;
 
                if (unlikely(mbox_seq_test(mbox, msg))) {
                        pr_info("mbox: Illegal seq bit!(%08x)\n", msg);
@@ -268,7 +287,7 @@ static void __mbox_rx_interrupt(struct omap_mbox *mbox)
                                mbox->err_notify();
                }
 
-               blk_insert_request(q, rq, 0, NULL);
+               blk_insert_request(q, rq, 0, (void *)msg);
                if (mbox->ops->type == OMAP_MBOX_TYPE1)
                        break;
        }
@@ -331,7 +350,7 @@ omap_mbox_read(struct device *dev, struct device_attribute *attr, char *buf)
                if (!rq)
                        break;
 
-               *p = (mbox_msg_t) rq->data;
+               *p = (mbox_msg_t)rq->special;
 
                blk_end_request_all(rq, 0);