@@ -82,7 +82,9 @@ struct gsi_trans_pool {
struct gsi_trans_info {
atomic_t tre_avail; /* TREs available for allocation */
- struct gsi_trans_pool pool; /* transaction pool */
+
+ u16 free_id; /* first free trans in array */
+ struct gsi_trans *trans; /* transaction array */
struct gsi_trans **map; /* TRE -> transaction map */
struct gsi_trans_pool sg_pool; /* scatterlist pool */
@@ -343,20 +343,22 @@ struct gsi_trans *gsi_channel_trans_alloc(struct gsi *gsi, u32 channel_id,
struct gsi_channel *channel = &gsi->channel[channel_id];
struct gsi_trans_info *trans_info;
struct gsi_trans *trans;
+ u16 trans_index;
if (WARN_ON(tre_count > channel->trans_tre_max))
return NULL;
trans_info = &channel->trans_info;
- /* We reserve the TREs now, but consume them at commit time.
- * If there aren't enough available, we're done.
- */
+ /* If we can't reserve the TREs for the transaction, we're done */
if (!gsi_trans_tre_reserve(trans_info, tre_count))
return NULL;
- /* Allocate and initialize non-zero fields in the transaction */
- trans = gsi_trans_pool_alloc(&trans_info->pool, 1);
+ trans_index = trans_info->free_id % channel->tre_count;
+ trans = &trans_info->trans[trans_index];
+ memset(trans, 0, sizeof(*trans));
+
+ /* Initialize non-zero fields in the transaction */
trans->gsi = gsi;
trans->channel_id = channel_id;
trans->rsvd_count = tre_count;
@@ -367,15 +369,17 @@ struct gsi_trans *gsi_channel_trans_alloc(struct gsi *gsi, u32 channel_id,
sg_init_marker(trans->sgl, tre_count);
trans->direction = direction;
-
- spin_lock_bh(&trans_info->spinlock);
-
- list_add_tail(&trans->links, &trans_info->alloc);
-
- spin_unlock_bh(&trans_info->spinlock);
-
refcount_set(&trans->refcount, 1);
+ /* This free transaction will now be allocated */
+ trans_info->free_id++;
+
+ spin_lock_bh(&trans_info->spinlock);
+
+ list_add_tail(&trans->links, &trans_info->alloc);
+
+ spin_unlock_bh(&trans_info->spinlock);
+
return trans;
}
@@ -736,10 +740,11 @@ int gsi_channel_trans_init(struct gsi *gsi, u32 channel_id)
* 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)
+ trans_info->trans = kcalloc(tre_count, sizeof(*trans_info->trans),
+ GFP_KERNEL);
+ if (!trans_info->trans)
return -ENOMEM;
+ trans_info->free_id = 0; /* modulo channel->tre_count */
/* A completion event contains a pointer to the TRE that caused
* the event (which will be the last one used by the transaction).
@@ -777,7 +782,7 @@ int gsi_channel_trans_init(struct gsi *gsi, u32 channel_id)
err_map_free:
kfree(trans_info->map);
err_trans_free:
- gsi_trans_pool_exit(&trans_info->pool);
+ kfree(trans_info->trans);
dev_err(gsi->dev, "error %d initializing channel %u transactions\n",
ret, channel_id);
@@ -791,6 +796,6 @@ void gsi_channel_trans_exit(struct gsi_channel *channel)
struct gsi_trans_info *trans_info = &channel->trans_info;
gsi_trans_pool_exit(&trans_info->sg_pool);
- gsi_trans_pool_exit(&trans_info->pool);
+ kfree(trans_info->trans);
kfree(trans_info->map);
}
Transactions are always allocated one at a time. The maximum number of them we could ever need occurs if each TRE is assigned to a transaction. So a channel requires no more transactions than the number of TREs in its transfer ring. That number is known to be a power-of-2 less than 65536. The transaction pool abstraction is used for other things, but for transactions we can use a simple array of transaction structures, and use a free index to indicate which entry in the array is the next one free for allocation. By having the number of elements in the array be a power-of-2, we can use an ever-incrementing 16-bit free index, and use it modulo the array size. Distinguish a "trans_id" (whose value can exceed the number of entries in the transaction array) from a "trans_index" (which is less than the number of entries). Signed-off-by: Alex Elder <elder@linaro.org> --- drivers/net/ipa/gsi.h | 4 +++- drivers/net/ipa/gsi_trans.c | 39 +++++++++++++++++++++---------------- 2 files changed, 25 insertions(+), 18 deletions(-)