diff options
Diffstat (limited to 'drivers/net/ipa/gsi.c')
| -rw-r--r-- | drivers/net/ipa/gsi.c | 94 |
1 files changed, 39 insertions, 55 deletions
diff --git a/drivers/net/ipa/gsi.c b/drivers/net/ipa/gsi.c index 9e307eebd33f..bea2da1c4c51 100644 --- a/drivers/net/ipa/gsi.c +++ b/drivers/net/ipa/gsi.c @@ -1,7 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 /* Copyright (c) 2015-2018, The Linux Foundation. All rights reserved. - * Copyright (C) 2018-2021 Linaro Ltd. + * Copyright (C) 2018-2022 Linaro Ltd. */ #include <linux/types.h> @@ -56,9 +56,9 @@ * element can also contain an immediate command, requesting the IPA perform * actions other than data transfer. * - * Each TRE refers to a block of data--also located DRAM. After writing one - * or more TREs to a channel, the writer (either the IPA or an EE) writes a - * doorbell register to inform the receiving side how many elements have + * Each TRE refers to a block of data--also located in DRAM. After writing + * one or more TREs to a channel, the writer (either the IPA or an EE) writes + * a doorbell register to inform the receiving side how many elements have * been written. * * Each channel has a GSI "event ring" associated with it. An event ring @@ -710,43 +710,32 @@ static void gsi_evt_ring_program(struct gsi *gsi, u32 evt_ring_id) static struct gsi_trans *gsi_channel_trans_last(struct gsi_channel *channel) { struct gsi_trans_info *trans_info = &channel->trans_info; - const struct list_head *list; + u32 pending_id = trans_info->pending_id; struct gsi_trans *trans; - - spin_lock_bh(&trans_info->spinlock); - - /* There is a small chance a TX transaction got allocated just - * before we disabled transmits, so check for that. - */ - 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; - if (!list_empty(list)) - goto done; + u16 trans_id; + + if (channel->toward_ipa && pending_id != trans_info->free_id) { + /* There is a small chance a TX transaction got allocated + * just before we disabled transmits, so check for that. + * The last allocated, committed, or pending transaction + * precedes the first free transaction. + */ + trans_id = trans_info->free_id - 1; + } else if (trans_info->polled_id != pending_id) { + /* Otherwise (TX or RX) we want to wait for anything that + * has completed, or has been polled but not released yet. + * + * The last completed or polled transaction precedes the + * first pending transaction. + */ + trans_id = pending_id - 1; + } else { + return NULL; } - /* Otherwise (TX or RX) we want to wait for anything that - * has completed, or has been polled but not released yet. - */ - list = &trans_info->complete; - if (!list_empty(list)) - goto done; - list = &trans_info->polled; - if (list_empty(list)) - list = NULL; -done: - trans = list ? list_last_entry(list, struct gsi_trans, links) : NULL; - /* Caller will wait for this, so take a reference */ - if (trans) - refcount_inc(&trans->refcount); - - spin_unlock_bh(&trans_info->spinlock); + trans = &trans_info->trans[trans_id % channel->tre_count]; + refcount_inc(&trans->refcount); return trans; } @@ -1358,8 +1347,8 @@ gsi_event_trans(struct gsi *gsi, struct gsi_event *event) * we update transactions to record their actual received lengths. * * When an event for a TX channel arrives we use information in the - * transaction to report the number of requests and bytes have been - * transferred. + * transaction to report the number of requests and bytes that have + * been transferred. * * This function is called whenever we learn that the GSI hardware has filled * new events since the last time we checked. The ring's index field tells @@ -1485,8 +1474,8 @@ void gsi_channel_doorbell(struct gsi_channel *channel) iowrite32(val, gsi->virt + GSI_CH_C_DOORBELL_0_OFFSET(channel_id)); } -/* Consult hardware, move any newly completed transactions to completed list */ -static struct gsi_trans *gsi_channel_update(struct gsi_channel *channel) +/* Consult hardware, move newly completed transactions to completed state */ +void gsi_channel_update(struct gsi_channel *channel) { u32 evt_ring_id = channel->evt_ring_id; struct gsi *gsi = channel->gsi; @@ -1505,12 +1494,12 @@ static struct gsi_trans *gsi_channel_update(struct gsi_channel *channel) offset = GSI_EV_CH_E_CNTXT_4_OFFSET(evt_ring_id); index = gsi_ring_index(ring, ioread32(gsi->virt + offset)); if (index == ring->index % ring->count) - return NULL; + return; /* Get the transaction for the latest completed event. */ trans = gsi_event_trans(gsi, gsi_ring_virt(ring, index - 1)); if (!trans) - return NULL; + return; /* For RX channels, update each completed transaction with the number * of bytes that were actually received. For TX channels, report @@ -1518,8 +1507,6 @@ static struct gsi_trans *gsi_channel_update(struct gsi_channel *channel) * up the network stack. */ gsi_evt_ring_update(gsi, evt_ring_id, index); - - return gsi_channel_trans_complete(channel); } /** @@ -1528,21 +1515,18 @@ static struct gsi_trans *gsi_channel_update(struct gsi_channel *channel) * * Return: Transaction pointer, or null if none are available * - * This function returns the first entry on a channel's completed transaction - * list. If that list is empty, the hardware is consulted to determine - * whether any new transactions have completed. If so, they're moved to the - * completed list and the new first entry is returned. If there are no more - * completed transactions, a null pointer is returned. + * This function returns the first of a channel's completed transactions. + * If no transactions are in completed state, the hardware is consulted to + * determine whether any new transactions have completed. If so, they're + * moved to completed state and the first such transaction is returned. + * If there are no more completed transactions, a null pointer is returned. */ static struct gsi_trans *gsi_channel_poll_one(struct gsi_channel *channel) { struct gsi_trans *trans; - /* Get the first transaction from the completed list */ + /* Get the first completed transaction */ trans = gsi_channel_trans_complete(channel); - if (!trans) /* List is empty; see if there's more to do */ - trans = gsi_channel_update(channel); - if (trans) gsi_trans_move_polled(trans); @@ -1623,7 +1607,7 @@ static int gsi_channel_setup_one(struct gsi *gsi, u32 channel_id) gsi_channel_poll); else netif_napi_add(&gsi->dummy_dev, &channel->napi, - gsi_channel_poll, NAPI_POLL_WEIGHT); + gsi_channel_poll); return 0; |