1 files changed, 99 insertions, 98 deletions

diff --git a/drivers/net/ipa/gsi_trans.c b/drivers/net/ipa/gsi_trans.c
index 55f8fe7d2668..18e7e8c405be 100644
--- a/drivers/net/ipa/gsi_trans.c
+++ b/drivers/net/ipa/gsi_trans.c
@@ -214,26 +214,14 @@ void *gsi_trans_pool_alloc_dma(struct gsi_trans_pool *pool, dma_addr_t *addr)
 	return pool->base + offset;
 }
 
-/* Return the pool element that immediately follows the one given.
- * This only works done if elements are allocated one at a time.
- */
-void *gsi_trans_pool_next(struct gsi_trans_pool *pool, void *element)
+/* Map a TRE ring entry index to the transaction it is associated with */
+static void gsi_trans_map(struct gsi_trans *trans, u32 index)
 {
-	void *end = pool->base + pool->count * pool->size;
-
-	WARN_ON(element < pool->base);
-	WARN_ON(element >= end);
-	WARN_ON(pool->max_alloc != 1);
-
-	element += pool->size;
+	struct gsi_channel *channel = &trans->gsi->channel[trans->channel_id];
 
-	return element < end ? element : pool->base;
-}
+	/* The completion event will indicate the last TRE used */
+	index += trans->used_count - 1;
 
-/* Map a given ring entry index to the transaction associated with it */
-static void gsi_channel_trans_map(struct gsi_channel *channel, u32 index,
-				  struct gsi_trans *trans)
-{
 	/* Note: index *must* be used modulo the ring count here */
 	channel->trans_info.map[index % channel->tre_ring.count] = trans;
 }
@@ -253,15 +241,31 @@ struct gsi_trans *gsi_channel_trans_complete(struct gsi_channel *channel)
 					struct gsi_trans, links);
 }
 
-/* Move a transaction from the allocated list to the pending list */
+/* Move a transaction from the allocated list to the committed list */
+static void gsi_trans_move_committed(struct gsi_trans *trans)
+{
+	struct gsi_channel *channel = &trans->gsi->channel[trans->channel_id];
+	struct gsi_trans_info *trans_info = &channel->trans_info;
+
+	spin_lock_bh(&trans_info->spinlock);
+
+	list_move_tail(&trans->links, &trans_info->committed);
+
+	spin_unlock_bh(&trans_info->spinlock);
+}
+
+/* Move transactions from the committed list to the pending list */
 static void gsi_trans_move_pending(struct gsi_trans *trans)
 {
 	struct gsi_channel *channel = &trans->gsi->channel[trans->channel_id];
 	struct gsi_trans_info *trans_info = &channel->trans_info;
+	struct list_head list;
 
 	spin_lock_bh(&trans_info->spinlock);
 
-	list_move_tail(&trans->links, &trans_info->pending);
+	/* Move this transaction and all predecessors to the pending list */
+	list_cut_position(&list, &trans_info->committed, &trans->links);
+	list_splice_tail(&list, &trans_info->pending);
 
 	spin_unlock_bh(&trans_info->spinlock);
 }
@@ -340,7 +344,7 @@ struct gsi_trans *gsi_channel_trans_alloc(struct gsi *gsi, u32 channel_id,
 	struct gsi_trans_info *trans_info;
 	struct gsi_trans *trans;
 
-	if (WARN_ON(tre_count > gsi_channel_trans_tre_max(gsi, channel_id)))
+	if (WARN_ON(tre_count > channel->trans_tre_max))
 		return NULL;
 
 	trans_info = &channel->trans_info;
@@ -351,14 +355,14 @@ struct gsi_trans *gsi_channel_trans_alloc(struct gsi *gsi, u32 channel_id,
 	if (!gsi_trans_tre_reserve(trans_info, tre_count))
 		return NULL;
 
-	/* Allocate and initialize non-zero fields in the the transaction */
+	/* Allocate and initialize non-zero fields in the transaction */
 	trans = gsi_trans_pool_alloc(&trans_info->pool, 1);
 	trans->gsi = gsi;
 	trans->channel_id = channel_id;
-	trans->tre_count = tre_count;
+	trans->rsvd_count = tre_count;
 	init_completion(&trans->completion);
 
-	/* Allocate the scatterlist and (if requested) info entries. */
+	/* Allocate the scatterlist */
 	trans->sgl = gsi_trans_pool_alloc(&trans_info->sg_pool, tre_count);
 	sg_init_marker(trans->sgl, tre_count);
 
@@ -400,22 +404,23 @@ void gsi_trans_free(struct gsi_trans *trans)
 	if (!last)
 		return;
 
-	ipa_gsi_trans_release(trans);
+	if (trans->used_count)
+		ipa_gsi_trans_release(trans);
 
 	/* Releasing the reserved TREs implicitly frees the sgl[] and
 	 * (if present) info[] arrays, plus the transaction itself.
 	 */
-	gsi_trans_tre_release(trans_info, trans->tre_count);
+	gsi_trans_tre_release(trans_info, trans->rsvd_count);
 }
 
 /* Add an immediate command to a transaction */
 void gsi_trans_cmd_add(struct gsi_trans *trans, void *buf, u32 size,
 		       dma_addr_t addr, enum ipa_cmd_opcode opcode)
 {
-	u32 which = trans->used++;
+	u32 which = trans->used_count++;
 	struct scatterlist *sg;
 
-	WARN_ON(which >= trans->tre_count);
+	WARN_ON(which >= trans->rsvd_count);
 
 	/* Commands are quite different from data transfer requests.
 	 * Their payloads come from a pool whose memory is allocated
@@ -446,9 +451,9 @@ int gsi_trans_page_add(struct gsi_trans *trans, struct page *page, u32 size,
 	struct scatterlist *sg = &trans->sgl[0];
 	int ret;
 
-	if (WARN_ON(trans->tre_count != 1))
+	if (WARN_ON(trans->rsvd_count != 1))
 		return -EINVAL;
-	if (WARN_ON(trans->used))
+	if (WARN_ON(trans->used_count))
 		return -EINVAL;
 
 	sg_set_page(sg, page, size, offset);
@@ -456,7 +461,7 @@ int gsi_trans_page_add(struct gsi_trans *trans, struct page *page, u32 size,
 	if (!ret)
 		return -ENOMEM;
 
-	trans->used++;	/* Transaction now owns the (DMA mapped) page */
+	trans->used_count++;	/* Transaction now owns the (DMA mapped) page */
 
 	return 0;
 }
@@ -465,25 +470,26 @@ int gsi_trans_page_add(struct gsi_trans *trans, struct page *page, u32 size,
 int gsi_trans_skb_add(struct gsi_trans *trans, struct sk_buff *skb)
 {
 	struct scatterlist *sg = &trans->sgl[0];
-	u32 used;
+	u32 used_count;
 	int ret;
 
-	if (WARN_ON(trans->tre_count != 1))
+	if (WARN_ON(trans->rsvd_count != 1))
 		return -EINVAL;
-	if (WARN_ON(trans->used))
+	if (WARN_ON(trans->used_count))
 		return -EINVAL;
 
 	/* skb->len will not be 0 (checked early) */
 	ret = skb_to_sgvec(skb, sg, 0, skb->len);
 	if (ret < 0)
 		return ret;
-	used = ret;
+	used_count = ret;
 
-	ret = dma_map_sg(trans->gsi->dev, sg, used, trans->direction);
+	ret = dma_map_sg(trans->gsi->dev, sg, used_count, trans->direction);
 	if (!ret)
 		return -ENOMEM;
 
-	trans->used += used;	/* Transaction now owns the (DMA mapped) skb */
+	/* Transaction now owns the (DMA mapped) skb */
+	trans->used_count += used_count;
 
 	return 0;
 }
@@ -549,7 +555,7 @@ static void gsi_trans_tre_fill(struct gsi_tre *dest_tre, dma_addr_t addr,
 static void __gsi_trans_commit(struct gsi_trans *trans, bool ring_db)
 {
 	struct gsi_channel *channel = &trans->gsi->channel[trans->channel_id];
-	struct gsi_ring *ring = &channel->tre_ring;
+	struct gsi_ring *tre_ring = &channel->tre_ring;
 	enum ipa_cmd_opcode opcode = IPA_CMD_NONE;
 	bool bei = channel->toward_ipa;
 	struct gsi_tre *dest_tre;
@@ -559,7 +565,7 @@ static void __gsi_trans_commit(struct gsi_trans *trans, bool ring_db)
 	u32 avail;
 	u32 i;
 
-	WARN_ON(!trans->used);
+	WARN_ON(!trans->used_count);
 
 	/* Consume the entries.  If we cross the end of the ring while
 	 * filling them we'll switch to the beginning to finish.
@@ -567,43 +573,39 @@ static void __gsi_trans_commit(struct gsi_trans *trans, bool ring_db)
 	 * transfer request, whose opcode is IPA_CMD_NONE.
 	 */
 	cmd_opcode = channel->command ? &trans->cmd_opcode[0] : NULL;
-	avail = ring->count - ring->index % ring->count;
-	dest_tre = gsi_ring_virt(ring, ring->index);
-	for_each_sg(trans->sgl, sg, trans->used, i) {
-		bool last_tre = i == trans->used - 1;
+	avail = tre_ring->count - tre_ring->index % tre_ring->count;
+	dest_tre = gsi_ring_virt(tre_ring, tre_ring->index);
+	for_each_sg(trans->sgl, sg, trans->used_count, i) {
+		bool last_tre = i == trans->used_count - 1;
 		dma_addr_t addr = sg_dma_address(sg);
 		u32 len = sg_dma_len(sg);
 
 		byte_count += len;
 		if (!avail--)
-			dest_tre = gsi_ring_virt(ring, 0);
+			dest_tre = gsi_ring_virt(tre_ring, 0);
 		if (cmd_opcode)
 			opcode = *cmd_opcode++;
 
 		gsi_trans_tre_fill(dest_tre, addr, len, last_tre, bei, opcode);
 		dest_tre++;
 	}
-	ring->index += trans->used;
-
-	if (channel->toward_ipa) {
-		/* We record TX bytes when they are sent */
-		trans->len = byte_count;
-		trans->trans_count = channel->trans_count;
-		trans->byte_count = channel->byte_count;
-		channel->trans_count++;
-		channel->byte_count += byte_count;
-	}
+	/* Associate the TRE with the transaction */
+	gsi_trans_map(trans, tre_ring->index);
 
-	/* Associate the last TRE with the transaction */
-	gsi_channel_trans_map(channel, ring->index - 1, trans);
+	tre_ring->index += trans->used_count;
 
-	gsi_trans_move_pending(trans);
+	trans->len = byte_count;
+	if (channel->toward_ipa)
+		gsi_trans_tx_committed(trans);
+
+	gsi_trans_move_committed(trans);
 
 	/* Ring doorbell if requested, or if all TREs are allocated */
 	if (ring_db || !atomic_read(&channel->trans_info.tre_avail)) {
 		/* Report what we're handing off to hardware for TX channels */
 		if (channel->toward_ipa)
-			gsi_channel_tx_queued(channel);
+			gsi_trans_tx_queued(trans);
+		gsi_trans_move_pending(trans);
 		gsi_channel_doorbell(channel);
 	}
 }
@@ -611,7 +613,7 @@ static void __gsi_trans_commit(struct gsi_trans *trans, bool ring_db)
 /* Commit a GSI transaction */
 void gsi_trans_commit(struct gsi_trans *trans, bool ring_db)
 {
-	if (trans->used)
+	if (trans->used_count)
 		__gsi_trans_commit(trans, ring_db);
 	else
 		gsi_trans_free(trans);
@@ -620,7 +622,7 @@ void gsi_trans_commit(struct gsi_trans *trans, bool ring_db)
 /* Commit a GSI transaction and wait for it to complete */
 void gsi_trans_commit_wait(struct gsi_trans *trans)
 {
-	if (!trans->used)
+	if (!trans->used_count)
 		goto out_trans_free;
 
 	refcount_inc(&trans->refcount);
@@ -638,7 +640,7 @@ void gsi_trans_complete(struct gsi_trans *trans)
 {
 	/* If the entire SGL was mapped when added, unmap it now */
 	if (trans->direction != DMA_NONE)
-		dma_unmap_sg(trans->gsi->dev, trans->sgl, trans->used,
+		dma_unmap_sg(trans->gsi->dev, trans->sgl, trans->used_count,
 			     trans->direction);
 
 	ipa_gsi_trans_complete(trans);
@@ -675,7 +677,7 @@ void gsi_channel_trans_cancel_pending(struct gsi_channel *channel)
 int gsi_trans_read_byte(struct gsi *gsi, u32 channel_id, dma_addr_t addr)
 {
 	struct gsi_channel *channel = &gsi->channel[channel_id];
-	struct gsi_ring *ring = &channel->tre_ring;
+	struct gsi_ring *tre_ring = &channel->tre_ring;
 	struct gsi_trans_info *trans_info;
 	struct gsi_tre *dest_tre;
 
@@ -685,12 +687,12 @@ int gsi_trans_read_byte(struct gsi *gsi, u32 channel_id, dma_addr_t addr)
 	if (!gsi_trans_tre_reserve(trans_info, 1))
 		return -EBUSY;
 
-	/* Now fill the the reserved TRE and tell the hardware */
+	/* Now fill the reserved TRE and tell the hardware */
 
-	dest_tre = gsi_ring_virt(ring, ring->index);
+	dest_tre = gsi_ring_virt(tre_ring, tre_ring->index);
 	gsi_trans_tre_fill(dest_tre, addr, 1, true, false, IPA_CMD_NONE);
 
-	ring->index++;
+	tre_ring->index++;
 	gsi_channel_doorbell(channel);
 
 	return 0;
@@ -708,6 +710,7 @@ void gsi_trans_read_byte_done(struct gsi *gsi, u32 channel_id)
 int gsi_channel_trans_init(struct gsi *gsi, u32 channel_id)
 {
 	struct gsi_channel *channel = &gsi->channel[channel_id];
+	u32 tre_count = channel->tre_count;
 	struct gsi_trans_info *trans_info;
 	u32 tre_max;
 	int ret;
@@ -715,68 +718,66 @@ int gsi_channel_trans_init(struct gsi *gsi, u32 channel_id)
 	/* Ensure the size of a channel element is what's expected */
 	BUILD_BUG_ON(sizeof(struct gsi_tre) != GSI_RING_ELEMENT_SIZE);
 
-	/* The map array is used to determine what transaction is associated
-	 * with a TRE that the hardware reports has completed.  We need one
-	 * map entry per TRE.
-	 */
 	trans_info = &channel->trans_info;
-	trans_info->map = kcalloc(channel->tre_count, sizeof(*trans_info->map),
-				  GFP_KERNEL);
-	if (!trans_info->map)
-		return -ENOMEM;
 
-	/* We can't use more TREs than there are available in the ring.
-	 * This limits the number of transactions that can be oustanding.
-	 * Worst case is one TRE per transaction (but we actually limit
-	 * it to something a little less than that).  We allocate resources
-	 * for transactions (including transaction structures) based on
-	 * this maximum number.
+	/* The tre_avail field is what ultimately limits the number of
+	 * outstanding transactions and their resources.  A transaction
+	 * allocation succeeds only if the TREs available are sufficient
+	 * for what the transaction might need.
 	 */
 	tre_max = gsi_channel_tre_max(channel->gsi, channel_id);
+	atomic_set(&trans_info->tre_avail, tre_max);
 
-	/* Transactions are allocated one at a time. */
+	/* We can't use more TREs than the number available in the ring.
+	 * This limits the number of transactions that can be outstanding.
+	 * Worst case is one TRE per transaction (but we actually limit
+	 * it to something a little less than that).  By allocating a
+	 * power-of-two number of transactions we can use an index
+	 * modulo that number to determine the next one that's free.
+	 * Transactions are allocated one at a time.
+	 */
 	ret = gsi_trans_pool_init(&trans_info->pool, sizeof(struct gsi_trans),
 				  tre_max, 1);
 	if (ret)
-		goto err_kfree;
+		return -ENOMEM;
+
+	/* A completion event contains a pointer to the TRE that caused
+	 * the event (which will be the last one used by the transaction).
+	 * Each entry in this map records the transaction associated
+	 * with a corresponding completed TRE.
+	 */
+	trans_info->map = kcalloc(tre_count, sizeof(*trans_info->map),
+				  GFP_KERNEL);
+	if (!trans_info->map) {
+		ret = -ENOMEM;
+		goto err_trans_free;
+	}
 
 	/* A transaction uses a scatterlist array to represent the data
 	 * transfers implemented by the transaction.  Each scatterlist
 	 * element is used to fill a single TRE when the transaction is
 	 * committed.  So we need as many scatterlist elements as the
 	 * maximum number of TREs that can be outstanding.
-	 *
-	 * All TREs in a transaction must fit within the channel's TLV FIFO.
-	 * A transaction on a channel can allocate as many TREs as that but
-	 * no more.
 	 */
 	ret = gsi_trans_pool_init(&trans_info->sg_pool,
 				  sizeof(struct scatterlist),
-				  tre_max, channel->tlv_count);
+				  tre_max, channel->trans_tre_max);
 	if (ret)
-		goto err_trans_pool_exit;
-
-	/* Finally, the tre_avail field is what ultimately limits the number
-	 * of outstanding transactions and their resources.  A transaction
-	 * allocation succeeds only if the TREs available are sufficient for
-	 * what the transaction might need.  Transaction resource pools are
-	 * sized based on the maximum number of outstanding TREs, so there
-	 * will always be resources available if there are TREs available.
-	 */
-	atomic_set(&trans_info->tre_avail, tre_max);
+		goto err_map_free;
 
 	spin_lock_init(&trans_info->spinlock);
 	INIT_LIST_HEAD(&trans_info->alloc);
+	INIT_LIST_HEAD(&trans_info->committed);
 	INIT_LIST_HEAD(&trans_info->pending);
 	INIT_LIST_HEAD(&trans_info->complete);
 	INIT_LIST_HEAD(&trans_info->polled);
 
 	return 0;
 
-err_trans_pool_exit:
-	gsi_trans_pool_exit(&trans_info->pool);
-err_kfree:
+err_map_free:
 	kfree(trans_info->map);
+err_trans_free:
+	gsi_trans_pool_exit(&trans_info->pool);
 
 	dev_err(gsi->dev, "error %d initializing channel %u transactions\n",
 		ret, channel_id);