3 files changed, 64 insertions, 68 deletions

diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig
index 78b49a626d0..111d39a47ad 100644
--- a/arch/arm/plat-omap/Kconfig
+++ b/arch/arm/plat-omap/Kconfig
@@ -106,6 +106,15 @@ config OMAP_MBOX_FWK
           Say Y here if you want to use OMAP Mailbox framework support for
           DSP, IVA1.0 and IVA2 in OMAP1/2/3.
 
+config OMAP_MBOX_KFIFO_SIZE
+        int "Mailbox kfifo default buffer size (bytes)"
+        depends on OMAP_MBOX_FWK
+        default 256
+        help
+          Specify the default size of mailbox's kfifo buffers (bytes).
+          This can also be changed at runtime (via the mbox_kfifo_size
+          module parameter).
+
 config OMAP_IOMMU
         tristate
 
diff --git a/arch/arm/plat-omap/include/plat/mailbox.h b/arch/arm/plat-omap/include/plat/mailbox.h
index 729166b76a7..0c3c4a5f4b4 100644
--- a/arch/arm/plat-omap/include/plat/mailbox.h
+++ b/arch/arm/plat-omap/include/plat/mailbox.h
@@ -5,8 +5,8 @@
 
 #include <linux/wait.h>
 #include <linux/workqueue.h>
-#include <linux/blkdev.h>
 #include <linux/interrupt.h>
+#include <linux/kfifo.h>
 
 typedef u32 mbox_msg_t;
 struct omap_mbox;
@@ -42,7 +42,7 @@ struct omap_mbox_ops {
 
 struct omap_mbox_queue {
         spinlock_t              lock;
-        struct request_queue    *queue;
+        struct kfifo            fifo;
         struct work_struct      work;
         struct tasklet_struct   tasklet;
         int     (*callback)(void *);
diff --git a/arch/arm/plat-omap/mailbox.c b/arch/arm/plat-omap/mailbox.c
index 81076b54d37..ec0e1596b4f 100644
--- a/arch/arm/plat-omap/mailbox.c
+++ b/arch/arm/plat-omap/mailbox.c
@@ -21,11 +21,14 @@
  *
  */
 
+#include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/interrupt.h>
 #include <linux/device.h>
 #include <linux/delay.h>
 #include <linux/slab.h>
+#include <linux/kfifo.h>
+#include <linux/err.h>
 
 #include <plat/mailbox.h>
 
@@ -37,6 +40,10 @@ static bool rq_full;
 static int mbox_configured;
 static DEFINE_MUTEX(mbox_configured_lock);
 
+static unsigned int mbox_kfifo_size = CONFIG_OMAP_MBOX_KFIFO_SIZE;
+module_param(mbox_kfifo_size, uint, S_IRUGO);
+MODULE_PARM_DESC(mbox_kfifo_size, "Size of omap's mailbox kfifo (bytes)");
+
 /* Mailbox FIFO handle functions */
 static inline mbox_msg_t mbox_fifo_read(struct omap_mbox *mbox)
 {
@@ -69,7 +76,7 @@ static inline int is_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
 /*
  * message sender
  */
-static int __mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg)
+static int __mbox_poll_for_space(struct omap_mbox *mbox)
 {
         int ret = 0, i = 1000;
 
@@ -80,49 +87,50 @@ static int __mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg)
                         return -1;
                 udelay(1);
         }
-        mbox_fifo_write(mbox, msg);
         return ret;
 }
 
-
 int omap_mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg)
 {
+        struct omap_mbox_queue *mq = mbox->txq;
+        int ret = 0, len;
 
-        struct request *rq;
-        struct request_queue *q = mbox->txq->queue;
+        spin_lock(&mq->lock);
 
-        rq = blk_get_request(q, WRITE, GFP_ATOMIC);
-        if (unlikely(!rq))
-                return -ENOMEM;
+        if (kfifo_avail(&mq->fifo) < sizeof(msg)) {
+                ret = -ENOMEM;
+                goto out;
+        }
+
+        len = kfifo_in(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
+        WARN_ON(len != sizeof(msg));
 
-        blk_insert_request(q, rq, 0, (void *) msg);
         tasklet_schedule(&mbox->txq->tasklet);
 
-        return 0;
+out:
+        spin_unlock(&mq->lock);
+        return ret;
 }
 EXPORT_SYMBOL(omap_mbox_msg_send);
 
 static void mbox_tx_tasklet(unsigned long tx_data)
 {
-        int ret;
-        struct request *rq;
         struct omap_mbox *mbox = (struct omap_mbox *)tx_data;
-        struct request_queue *q = mbox->txq->queue;
-
-        while (1) {
-
-                rq = blk_fetch_request(q);
-
-                if (!rq)
-                        break;
+        struct omap_mbox_queue *mq = mbox->txq;
+        mbox_msg_t msg;
+        int ret;
 
-                ret = __mbox_msg_send(mbox, (mbox_msg_t)rq->special);
-                if (ret) {
+        while (kfifo_len(&mq->fifo)) {
+                if (__mbox_poll_for_space(mbox)) {
                         omap_mbox_enable_irq(mbox, IRQ_TX);
-                        blk_requeue_request(q, rq);
-                        return;
+                        break;
                 }
-                blk_end_request_all(rq, 0);
+
+                ret = kfifo_out(&mq->fifo, (unsigned char *)&msg,
+                                                                sizeof(msg));
+                WARN_ON(ret != sizeof(msg));
+
+                mbox_fifo_write(mbox, msg);
         }
 }
 
@@ -133,41 +141,21 @@ static void mbox_rx_work(struct work_struct *work)
 {
         struct omap_mbox_queue *mq =
                         container_of(work, struct omap_mbox_queue, work);
-        struct omap_mbox *mbox = mq->queue->queuedata;
-        struct request_queue *q = mbox->rxq->queue;
-        struct request *rq;
         mbox_msg_t msg;
-        unsigned long flags;
-
-        while (1) {
-                spin_lock_irqsave(q->queue_lock, flags);
-                rq = blk_fetch_request(q);
-                if (rq_full) {
-                        omap_mbox_enable_irq(mbox, IRQ_RX);
-                        rq_full = false;
-                }
-                spin_unlock_irqrestore(q->queue_lock, flags);
-                if (!rq)
-                        break;
+        int len;
+
+        while (kfifo_len(&mq->fifo) >= sizeof(msg)) {
+                len = kfifo_out(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
+                WARN_ON(len != sizeof(msg));
 
-                msg = (mbox_msg_t)rq->special;
-                blk_end_request_all(rq, 0);
-                if (mbox->rxq->callback)
-                        mbox->rxq->callback((void *)msg);
+                if (mq->callback)
+                        mq->callback((void *)msg);
         }
 }
 
 /*
  * Mailbox interrupt handler
  */
-static void mbox_txq_fn(struct request_queue *q)
-{
-}
-
-static void mbox_rxq_fn(struct request_queue *q)
-{
-}
-
 static void __mbox_tx_interrupt(struct omap_mbox *mbox)
 {
         omap_mbox_disable_irq(mbox, IRQ_TX);
@@ -177,13 +165,12 @@ static void __mbox_tx_interrupt(struct omap_mbox *mbox)
 
 static void __mbox_rx_interrupt(struct omap_mbox *mbox)
 {
-        struct request *rq;
+        struct omap_mbox_queue *mq = mbox->rxq;
         mbox_msg_t msg;
-        struct request_queue *q = mbox->rxq->queue;
+        int len;
 
         while (!mbox_fifo_empty(mbox)) {
-                rq = blk_get_request(q, WRITE, GFP_ATOMIC);
-                if (unlikely(!rq)) {
+                if (unlikely(kfifo_avail(&mq->fifo) < sizeof(msg))) {
                         omap_mbox_disable_irq(mbox, IRQ_RX);
                         rq_full = true;
                         goto nomem;
@@ -191,8 +178,9 @@ static void __mbox_rx_interrupt(struct omap_mbox *mbox)
 
                 msg = mbox_fifo_read(mbox);
 
+                len = kfifo_in(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
+                WARN_ON(len != sizeof(msg));
 
-                blk_insert_request(q, rq, 0, (void *)msg);
                 if (mbox->ops->type == OMAP_MBOX_TYPE1)
                         break;
         }
@@ -217,11 +205,9 @@ 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 (*tasklet)(unsigned long))
 {
-        struct request_queue *q;
         struct omap_mbox_queue *mq;
 
         mq = kzalloc(sizeof(struct omap_mbox_queue), GFP_KERNEL);
@@ -230,11 +216,8 @@ static struct omap_mbox_queue *mbox_queue_alloc(struct omap_mbox *mbox,
 
         spin_lock_init(&mq->lock);
 
-        q = blk_init_queue(proc, &mq->lock);
-        if (!q)
+        if (kfifo_alloc(&mq->fifo, mbox_kfifo_size, GFP_KERNEL))
                 goto error;
-        q->queuedata = mbox;
-        mq->queue = q;
 
         if (work)
                 INIT_WORK(&mq->work, work);
@@ -249,7 +232,7 @@ error:
 
 static void mbox_queue_free(struct omap_mbox_queue *q)
 {
-        blk_cleanup_queue(q->queue);
+        kfifo_free(&q->fifo);
         kfree(q);
 }
 
@@ -279,14 +262,14 @@ static int omap_mbox_startup(struct omap_mbox *mbox)
                 goto fail_request_irq;
         }
 
-        mq = mbox_queue_alloc(mbox, mbox_txq_fn, NULL, mbox_tx_tasklet);
+        mq = mbox_queue_alloc(mbox, 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, NULL);
+        mq = mbox_queue_alloc(mbox, mbox_rx_work, NULL);
         if (!mq) {
                 ret = -ENOMEM;
                 goto fail_alloc_rxq;
@@ -418,6 +401,10 @@ static int __init omap_mbox_init(void)
         if (!mboxd)
                 return -ENOMEM;
 
+        /* kfifo size sanity check: alignment and minimal size */
+        mbox_kfifo_size = ALIGN(mbox_kfifo_size, sizeof(mbox_msg_t));
+        mbox_kfifo_size = max_t(unsigned int, mbox_kfifo_size, sizeof(mbox_msg_t));
+
         return 0;
 }
 module_init(omap_mbox_init);