mmc: queue: add a second mmc queue request member

Add an additional mmc queue request instance to make way for two active
block requests. One request may be active while the other request is
being prepared.

Signed-off-by: Per Forlin <per.forlin@linaro.org>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Venkatraman S <svenkatr@ti.com>
Tested-by: Sourav Poddar <sourav.poddar@ti.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/card/queue.c

@@ -153,6 +153,7 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
 	u64 limit = BLK_BOUNCE_HIGH;
 	int ret;
 	struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
+	struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
 
 	if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
 		limit = *mmc_dev(host)->dma_mask;
@@ -163,7 +164,9 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
 		return -ENOMEM;
 
 	memset(&mq->mqrq_cur, 0, sizeof(mq->mqrq_cur));
+	memset(&mq->mqrq_prev, 0, sizeof(mq->mqrq_prev));
 	mq->mqrq_cur = mqrq_cur;
+	mq->mqrq_prev = mqrq_prev;
 	mq->queue->queuedata = mq;
 
 	blk_queue_prep_rq(mq->queue, mmc_prep_request);
@@ -191,9 +194,17 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
 					"allocate bounce cur buffer\n",
 					mmc_card_name(card));
 			}
+			mqrq_prev->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
+			if (!mqrq_prev->bounce_buf) {
+				printk(KERN_WARNING "%s: unable to "
+					"allocate bounce prev buffer\n",
+					mmc_card_name(card));
+				kfree(mqrq_cur->bounce_buf);
+				mqrq_cur->bounce_buf = NULL;
+			}
 		}
 
-		if (mqrq_cur->bounce_buf) {
+		if (mqrq_cur->bounce_buf && mqrq_prev->bounce_buf) {
 			blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY);
 			blk_queue_max_hw_sectors(mq->queue, bouncesz / 512);
 			blk_queue_max_segments(mq->queue, bouncesz / 512);
@@ -208,11 +219,19 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
 			if (ret)
 				goto cleanup_queue;
 
+			mqrq_prev->sg = mmc_alloc_sg(1, &ret);
+			if (ret)
+				goto cleanup_queue;
+
+			mqrq_prev->bounce_sg =
+				mmc_alloc_sg(bouncesz / 512, &ret);
+			if (ret)
+				goto cleanup_queue;
 		}
 	}
 #endif
 
-	if (!mqrq_cur->bounce_buf) {
+	if (!mqrq_cur->bounce_buf && !mqrq_prev->bounce_buf) {
 		blk_queue_bounce_limit(mq->queue, limit);
 		blk_queue_max_hw_sectors(mq->queue,
 			min(host->max_blk_count, host->max_req_size / 512));
@@ -223,6 +242,10 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
 		if (ret)
 			goto cleanup_queue;
 
+
+		mqrq_prev->sg = mmc_alloc_sg(host->max_segs, &ret);
+		if (ret)
+			goto cleanup_queue;
 	}
 
 	sema_init(&mq->thread_sem, 1);
@@ -239,13 +262,20 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
  free_bounce_sg:
 	kfree(mqrq_cur->bounce_sg);
 	mqrq_cur->bounce_sg = NULL;
+	kfree(mqrq_prev->bounce_sg);
+	mqrq_prev->bounce_sg = NULL;
 
  cleanup_queue:
 	kfree(mqrq_cur->sg);
 	mqrq_cur->sg = NULL;
 	kfree(mqrq_cur->bounce_buf);
 	mqrq_cur->bounce_buf = NULL;
 
+	kfree(mqrq_prev->sg);
+	mqrq_prev->sg = NULL;
+	kfree(mqrq_prev->bounce_buf);
+	mqrq_prev->bounce_buf = NULL;
+
 	blk_cleanup_queue(mq->queue);
 	return ret;
 }
@@ -255,6 +285,7 @@ void mmc_cleanup_queue(struct mmc_queue *mq)
 	struct request_queue *q = mq->queue;
 	unsigned long flags;
 	struct mmc_queue_req *mqrq_cur = mq->mqrq_cur;
+	struct mmc_queue_req *mqrq_prev = mq->mqrq_prev;
 
 	/* Make sure the queue isn't suspended, as that will deadlock */
 	mmc_queue_resume(mq);
@@ -277,6 +308,15 @@ void mmc_cleanup_queue(struct mmc_queue *mq)
 	kfree(mqrq_cur->bounce_buf);
 	mqrq_cur->bounce_buf = NULL;
 
+	kfree(mqrq_prev->bounce_sg);
+	mqrq_prev->bounce_sg = NULL;
+
+	kfree(mqrq_prev->sg);
+	mqrq_prev->sg = NULL;
+
+	kfree(mqrq_prev->bounce_buf);
+	mqrq_prev->bounce_buf = NULL;
+
 	mq->card = NULL;
 }
 EXPORT_SYMBOL(mmc_cleanup_queue);

drivers/mmc/card/queue.h

@@ -29,8 +29,9 @@ struct mmc_queue {
 	int			(*issue_fn)(struct mmc_queue *, struct request *);
 	void			*data;
 	struct request_queue	*queue;
-	struct mmc_queue_req	mqrq[1];
+	struct mmc_queue_req	mqrq[2];
 	struct mmc_queue_req	*mqrq_cur;
+	struct mmc_queue_req	*mqrq_prev;
 };
 
 extern int mmc_init_queue(struct mmc_queue *, struct mmc_card *, spinlock_t *,