Hi Ohad,
From: ext Ohad Ben-Cohen <ohad@xxxxxxxxxx>
Subject: [PATCH 4/4] omap: mailbox: convert block api to kfifo
Date: Tue, 27 Apr 2010 19:56:22 +0200
> The underlying buffering implementation of mailbox
> is converted from block API to kfifo due to the simplicity
> and speed of kfifo.
>
> Signed-off-by: Ohad Ben-Cohen <ohad@xxxxxxxxxx>
> Signed-off-by: Hari Kanigeri <h-kanigeri2@xxxxxx>
> ---
> arch/arm/plat-omap/include/plat/mailbox.h | 5 +-
> arch/arm/plat-omap/mailbox.c | 108 +++++++++++++----------------
> 2 files changed, 52 insertions(+), 61 deletions(-)
>
> diff --git a/arch/arm/plat-omap/include/plat/mailbox.h b/arch/arm/plat-omap/include/plat/mailbox.h
> index 729166b..014cc58 100644
> --- a/arch/arm/plat-omap/include/plat/mailbox.h
> +++ b/arch/arm/plat-omap/include/plat/mailbox.h
> @@ -7,6 +7,7 @@
> #include <linux/workqueue.h>
> #include <linux/blkdev.h>
> #include <linux/interrupt.h>
> +#include <linux/kfifo.h>
>
> typedef u32 mbox_msg_t;
> struct omap_mbox;
> @@ -19,6 +20,8 @@ typedef int __bitwise omap_mbox_type_t;
> #define OMAP_MBOX_TYPE1 ((__force omap_mbox_type_t) 1)
> #define OMAP_MBOX_TYPE2 ((__force omap_mbox_type_t) 2)
>
> +#define MBOX_KFIFO_SIZE (256)
Can this be a module parameter? Then, OEM could set their optimized value.
> +
> struct omap_mbox_ops {
> omap_mbox_type_t type;
> int (*startup)(struct omap_mbox *mbox);
> @@ -42,7 +45,7 @@ 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 72b17ad..b1324f3 100644
> --- a/arch/arm/plat-omap/mailbox.c
> +++ b/arch/arm/plat-omap/mailbox.c
> @@ -26,6 +26,7 @@
> #include <linux/device.h>
> #include <linux/delay.h>
> #include <linux/slab.h>
> +#include <linux/kfifo.h>
>
> #include <plat/mailbox.h>
>
> @@ -67,7 +68,7 @@ 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;
>
> @@ -78,49 +79,54 @@ 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));
> + if (unlikely(len != sizeof(msg))) {
> + pr_err("%s: kfifo_in anomaly\n", __func__);
> + ret = -ENOMEM;
> + }
>
> - 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));
> + if (unlikely(ret != sizeof(msg)))
> + pr_err("%s: kfifo_out anomaly\n", __func__);
No error recovery? same for other anomalies.
> +
> + mbox_fifo_write(mbox, msg);
> }
> }
>
> @@ -131,36 +137,22 @@ 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;
> + int len;
>
> - while (1) {
> - spin_lock_irqsave(q->queue_lock, flags);
> - rq = blk_fetch_request(q);
> - spin_unlock_irqrestore(q->queue_lock, flags);
> - if (!rq)
> - break;
> + while (kfifo_len(&mq->fifo) >= sizeof(msg)) {
> + len = kfifo_out(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
> + if (unlikely(len != sizeof(msg)))
> + pr_err("%s: kfifo_out anomaly detected\n", __func__);
>
> - msg = (mbox_msg_t)rq->special;
> - blk_end_request_all(rq, 0);
> - 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);
> @@ -170,19 +162,20 @@ 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)))
> goto nomem;
>
> msg = mbox_fifo_read(mbox);
>
>
> - blk_insert_request(q, rq, 0, (void *)msg);
> + len = kfifo_in(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
> + if (unlikely(len != sizeof(msg)))
> + pr_err("%s: kfifo_in anomaly detected\n", __func__);
> if (mbox->ops->type == OMAP_MBOX_TYPE1)
> break;
> }
> @@ -207,11 +200,9 @@ 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);
> @@ -220,11 +211,8 @@ 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);
> @@ -239,7 +227,7 @@ error:
>
> static void mbox_queue_free(struct omap_mbox_queue *q)
> {
> - blk_cleanup_queue(q->queue);
> + kfifo_free(&q->fifo);
> kfree(q);
> }
>
> @@ -269,14 +257,14 @@ 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;
> --
> 1.6.3.3
>
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