From b63f507c06e6835aaefe89faee220aefedad0a1d Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Tue, 19 Jul 2022 13:10:16 -0500 Subject: [PATCH 1/5] net: ipa: add a transaction committed list We currently put a transaction on the pending list when it has been committed. But until the channel's doorbell rings, these transactions aren't actually "owned" by the hardware yet. Add a new "committed" state (and list), to represent transactions that have been committed but not yet sent to hardware. Define "pending" to mean committed transactions that have been sent to hardware but have not yet completed. Signed-off-by: Alex Elder Signed-off-by: Jakub Kicinski --- drivers/net/ipa/gsi.c | 5 ++++- drivers/net/ipa/gsi.h | 5 +++-- drivers/net/ipa/gsi_trans.c | 26 ++++++++++++++++++++++---- 3 files changed, 29 insertions(+), 7 deletions(-) diff --git a/drivers/net/ipa/gsi.c b/drivers/net/ipa/gsi.c index fcd05acf893b3..9e307eebd33f9 100644 --- a/drivers/net/ipa/gsi.c +++ b/drivers/net/ipa/gsi.c @@ -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. */ diff --git a/drivers/net/ipa/gsi.h b/drivers/net/ipa/gsi.h index 982c57550ef37..85fb03465713f 100644 --- a/drivers/net/ipa/gsi.h +++ b/drivers/net/ipa/gsi.h @@ -89,7 +89,8 @@ struct gsi_trans_info { 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 +186,7 @@ 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); diff --git a/drivers/net/ipa/gsi_trans.c b/drivers/net/ipa/gsi_trans.c index 29496ca15825f..45572ebb76e95 100644 --- a/drivers/net/ipa/gsi_trans.c +++ b/drivers/net/ipa/gsi_trans.c @@ -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 */ +/* 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); } @@ -581,13 +597,14 @@ 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); } } @@ -710,7 +727,7 @@ int gsi_channel_trans_init(struct gsi *gsi, u32 channel_id) 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. + * 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). We allocate resources * for transactions (including transaction structures) based on @@ -747,6 +764,7 @@ int gsi_channel_trans_init(struct gsi *gsi, u32 channel_id) 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); From 4920065888fa27edf1cb3f2d03c6d1c245e493bf Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Tue, 19 Jul 2022 13:10:17 -0500 Subject: [PATCH 2/5] net: ipa: rearrange transaction initialization The transaction map is really associated with the transaction pool; move its definition earlier in the gsi_trans_info structure. Rearrange initialization in gsi_channel_trans_init() so it sets the tre_avail value first, then initializes the transaction pool, and finally allocating the transaction map. Update comments. Signed-off-by: Alex Elder Signed-off-by: Jakub Kicinski --- drivers/net/ipa/gsi.h | 3 +- drivers/net/ipa/gsi_trans.c | 60 +++++++++++++++++++------------------ 2 files changed, 33 insertions(+), 30 deletions(-) diff --git a/drivers/net/ipa/gsi.h b/drivers/net/ipa/gsi.h index 85fb03465713f..23de5f67374cf 100644 --- a/drivers/net/ipa/gsi.h +++ b/drivers/net/ipa/gsi.h @@ -83,9 +83,10 @@ 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 */ diff --git a/drivers/net/ipa/gsi_trans.c b/drivers/net/ipa/gsi_trans.c index 45572ebb76e95..3f52932e9e413 100644 --- a/drivers/net/ipa/gsi_trans.c +++ b/drivers/net/ipa/gsi_trans.c @@ -709,6 +709,7 @@ 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; @@ -716,30 +717,40 @@ 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 outstanding. - * 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 @@ -751,16 +762,7 @@ 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); @@ -771,10 +773,10 @@ int gsi_channel_trans_init(struct gsi *gsi, u32 channel_id) 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); From 4d8996cbeeabba028714d0e0bd5957b5515cae43 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Tue, 19 Jul 2022 13:10:18 -0500 Subject: [PATCH 3/5] net: ipa: skip some cleanup for unused transactions In gsi_trans_free(), there's no point in ipa_gsi_trans_release() if a transaction is unused. No used TREs means no IPA layer resources to clean up. So only call ipa_gsi_trans_release() if at least one TRE was used. Signed-off-by: Alex Elder Signed-off-by: Jakub Kicinski --- drivers/net/ipa/gsi_trans.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/ipa/gsi_trans.c b/drivers/net/ipa/gsi_trans.c index 3f52932e9e413..55987e35af2dd 100644 --- a/drivers/net/ipa/gsi_trans.c +++ b/drivers/net/ipa/gsi_trans.c @@ -404,7 +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. From 3c91c86d1bb61bd59d3b9a0b8003fe272fc9e774 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Tue, 19 Jul 2022 13:10:19 -0500 Subject: [PATCH 4/5] net: ipa: report when the driver has been removed When the IPA driver has completed its initialization and setup stages, it emits a brief message to the log. Add a small message that reports when it has been removed. Signed-off-by: Alex Elder Signed-off-by: Jakub Kicinski --- drivers/net/ipa/ipa_main.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/ipa/ipa_main.c b/drivers/net/ipa/ipa_main.c index b989259b02047..32962d885acd5 100644 --- a/drivers/net/ipa/ipa_main.c +++ b/drivers/net/ipa/ipa_main.c @@ -836,6 +836,8 @@ static int ipa_remove(struct platform_device *pdev) kfree(ipa); ipa_power_exit(power); + dev_info(dev, "IPA driver removed"); + return 0; } From 616c4a83b6eaf2e517849d90203ac1c3f6f61b57 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Tue, 19 Jul 2022 13:10:20 -0500 Subject: [PATCH 5/5] net: ipa: fix an outdated comment Since commit 8797972afff3d ("net: ipa: remove command info pool"), we don't allocate "command info" entries for command channel transactions. Fix a comment that seems to suggest we still do. (Even before that commit, the comment was out of place.) Signed-off-by: Alex Elder Signed-off-by: Jakub Kicinski --- drivers/net/ipa/gsi_trans.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ipa/gsi_trans.c b/drivers/net/ipa/gsi_trans.c index 55987e35af2dd..18e7e8c405bea 100644 --- a/drivers/net/ipa/gsi_trans.c +++ b/drivers/net/ipa/gsi_trans.c @@ -362,7 +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);