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Merge branch 'net-ipa-small-transaction-updates'

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Alex Elder says:

====================
net: ipa: small transaction updates

Version 2 of this series corrects a misspelling of "outstanding"
pointed out by the netdev test bots.  (For some reason I don't see
that when I run "checkpatch".)  I found and fixed a second instance
of that word being misspelled as well.

This series includes three changes to the transaction code.  The
first adds a new transaction list that represents a distinct state
that has not been maintained.  The second moves a field in the
transaction information structure, and reorders its initialization
a bit.  The third skips a function call when it is known not to be
necessary.

The last two are very small "leftover" patches.
====================

Link: https://lore.kernel.org/r/20220719181020.372697-1-elder@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Jakub Kicinski 2022-07-20 21:05:07 -07:00
commit 4ab6e359f8
4 changed files with 67 additions and 39 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
drivers/net/ipa/gsi.c
View File

@ -720,6 +720,9 @@ static struct gsi_trans *gsi_channel_trans_last(struct gsi_channel *channel)
*/
if (channel->toward_ipa) {
list = &trans_info->alloc;
if (!list_empty(list))
goto done;
list = &trans_info->committed;
if (!list_empty(list))
goto done;
list = &trans_info->pending;
@ -1364,7 +1367,7 @@ gsi_event_trans(struct gsi *gsi, struct gsi_event *event)
* first *unfilled* event in the ring (following the last filled one).
*
* Events are sequential within the event ring, and transactions are
* sequential within the transaction pool.
* sequential within the transaction array.
*
* Note that @index always refers to an element *within* the event ring.
*/

8
drivers/net/ipa/gsi.h
View File

@ -83,13 +83,15 @@ struct gsi_trans_pool {
struct gsi_trans_info {
atomic_t tre_avail; /* TREs available for allocation */
struct gsi_trans_pool pool; /* transaction pool */
struct gsi_trans **map; /* TRE -> transaction map */
struct gsi_trans_pool sg_pool; /* scatterlist pool */
struct gsi_trans_pool cmd_pool; /* command payload DMA pool */
struct gsi_trans **map; /* TRE -> transaction map */
spinlock_t spinlock; /* protects updates to the lists */
struct list_head alloc; /* allocated, not committed */
struct list_head pending; /* committed, awaiting completion */
struct list_head committed; /* committed, awaiting doorbell */
struct list_head pending; /* pending, awaiting completion */
struct list_head complete; /* completed, awaiting poll */
struct list_head polled; /* returned by gsi_channel_poll_one() */
};
@ -185,7 +187,7 @@ void gsi_teardown(struct gsi *gsi);
* @gsi: GSI pointer
* @channel_id: Channel whose limit is to be returned
*
* Return: The maximum number of TREs oustanding on the channel
* Return: The maximum number of TREs outstanding on the channel
*/
u32 gsi_channel_tre_max(struct gsi *gsi, u32 channel_id);

91
drivers/net/ipa/gsi_trans.c
View File

@ -241,15 +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 */
static void gsi_trans_move_pending(struct gsi_trans *trans)
/* 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->pending);
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);
/* 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);
}
@ -346,7 +362,7 @@ struct gsi_trans *gsi_channel_trans_alloc(struct gsi *gsi, u32 channel_id,
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);
@ -388,7 +404,8 @@ 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.
@ -581,13 +598,14 @@ static void __gsi_trans_commit(struct gsi_trans *trans, bool ring_db)
if (channel->toward_ipa)
gsi_trans_tx_committed(trans);
gsi_trans_move_pending(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_trans_tx_queued(trans);
gsi_trans_move_pending(trans);
gsi_channel_doorbell(channel);
}
}
@ -692,6 +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;
@ -699,30 +718,40 @@ 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
@ -734,29 +763,21 @@ int gsi_channel_trans_init(struct gsi *gsi, u32 channel_id)
sizeof(struct scatterlist),
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);

2
drivers/net/ipa/ipa_main.c
View File

@ -836,6 +836,8 @@ out_power_put:
kfree(ipa);
ipa_power_exit(power);
dev_info(dev, "IPA driver removed");
return 0;
}