From 255ba06533f09875973d6b400f9c5b88065938df Mon Sep 17 00:00:00 2001 From: Emmanuel Grumbach Date: Sat, 11 Jul 2015 22:30:49 +0300 Subject: [PATCH] Revert "iwlwifi: pcie: New RBD allocation model" This reverts commit 5f17570354f91275b0a37a4da33d29a2ab57d32e. This patch introduced a high latency in buffer allocation under extreme load. This latency caused a firmwre crash. The same scenario works fine with this patch reverted. Signed-off-by: Emmanuel Grumbach --- drivers/net/wireless/iwlwifi/iwl-fh.h | 6 + drivers/net/wireless/iwlwifi/pcie/internal.h | 51 +-- drivers/net/wireless/iwlwifi/pcie/rx.c | 414 ++++--------------- 3 files changed, 97 insertions(+), 374 deletions(-) diff --git a/drivers/net/wireless/iwlwifi/iwl-fh.h b/drivers/net/wireless/iwlwifi/iwl-fh.h index d56064861a9c..d45dc021cda2 100644 --- a/drivers/net/wireless/iwlwifi/iwl-fh.h +++ b/drivers/net/wireless/iwlwifi/iwl-fh.h @@ -438,6 +438,12 @@ static inline unsigned int FH_MEM_CBBC_QUEUE(unsigned int chnl) #define RX_QUEUE_MASK 255 #define RX_QUEUE_SIZE_LOG 8 +/* + * RX related structures and functions + */ +#define RX_FREE_BUFFERS 64 +#define RX_LOW_WATERMARK 8 + /** * struct iwl_rb_status - reserve buffer status * host memory mapped FH registers diff --git a/drivers/net/wireless/iwlwifi/pcie/internal.h b/drivers/net/wireless/iwlwifi/pcie/internal.h index 31f72a61cc3f..376b84e54ad7 100644 --- a/drivers/net/wireless/iwlwifi/pcie/internal.h +++ b/drivers/net/wireless/iwlwifi/pcie/internal.h @@ -44,15 +44,6 @@ #include "iwl-io.h" #include "iwl-op-mode.h" -/* - * RX related structures and functions - */ -#define RX_NUM_QUEUES 1 -#define RX_POST_REQ_ALLOC 2 -#define RX_CLAIM_REQ_ALLOC 8 -#define RX_POOL_SIZE ((RX_CLAIM_REQ_ALLOC - RX_POST_REQ_ALLOC) * RX_NUM_QUEUES) -#define RX_LOW_WATERMARK 8 - struct iwl_host_cmd; /*This file includes the declaration that are internal to the @@ -86,29 +77,29 @@ struct isr_statistics { * struct iwl_rxq - Rx queue * @bd: driver's pointer to buffer of receive buffer descriptors (rbd) * @bd_dma: bus address of buffer of receive buffer descriptors (rbd) + * @pool: + * @queue: * @read: Shared index to newest available Rx buffer * @write: Shared index to oldest written Rx packet * @free_count: Number of pre-allocated buffers in rx_free - * @used_count: Number of RBDs handled to allocator to use for allocation * @write_actual: - * @rx_free: list of RBDs with allocated RB ready for use - * @rx_used: list of RBDs with no RB attached + * @rx_free: list of free SKBs for use + * @rx_used: List of Rx buffers with no SKB * @need_update: flag to indicate we need to update read/write index * @rb_stts: driver's pointer to receive buffer status * @rb_stts_dma: bus address of receive buffer status * @lock: - * @pool: initial pool of iwl_rx_mem_buffer for the queue - * @queue: actual rx queue * * NOTE: rx_free and rx_used are used as a FIFO for iwl_rx_mem_buffers */ struct iwl_rxq { __le32 *bd; dma_addr_t bd_dma; + struct iwl_rx_mem_buffer pool[RX_QUEUE_SIZE + RX_FREE_BUFFERS]; + struct iwl_rx_mem_buffer *queue[RX_QUEUE_SIZE]; u32 read; u32 write; u32 free_count; - u32 used_count; u32 write_actual; struct list_head rx_free; struct list_head rx_used; @@ -116,32 +107,6 @@ struct iwl_rxq { struct iwl_rb_status *rb_stts; dma_addr_t rb_stts_dma; spinlock_t lock; - struct iwl_rx_mem_buffer pool[RX_QUEUE_SIZE]; - struct iwl_rx_mem_buffer *queue[RX_QUEUE_SIZE]; -}; - -/** - * struct iwl_rb_allocator - Rx allocator - * @pool: initial pool of allocator - * @req_pending: number of requests the allcator had not processed yet - * @req_ready: number of requests honored and ready for claiming - * @rbd_allocated: RBDs with pages allocated and ready to be handled to - * the queue. This is a list of &struct iwl_rx_mem_buffer - * @rbd_empty: RBDs with no page attached for allocator use. This is a list - * of &struct iwl_rx_mem_buffer - * @lock: protects the rbd_allocated and rbd_empty lists - * @alloc_wq: work queue for background calls - * @rx_alloc: work struct for background calls - */ -struct iwl_rb_allocator { - struct iwl_rx_mem_buffer pool[RX_POOL_SIZE]; - atomic_t req_pending; - atomic_t req_ready; - struct list_head rbd_allocated; - struct list_head rbd_empty; - spinlock_t lock; - struct workqueue_struct *alloc_wq; - struct work_struct rx_alloc; }; struct iwl_dma_ptr { @@ -285,7 +250,7 @@ iwl_pcie_get_scratchbuf_dma(struct iwl_txq *txq, int idx) /** * struct iwl_trans_pcie - PCIe transport specific data * @rxq: all the RX queue data - * @rba: allocator for RX replenishing + * @rx_replenish: work that will be called when buffers need to be allocated * @drv - pointer to iwl_drv * @trans: pointer to the generic transport area * @scd_base_addr: scheduler sram base address in SRAM @@ -308,7 +273,7 @@ iwl_pcie_get_scratchbuf_dma(struct iwl_txq *txq, int idx) */ struct iwl_trans_pcie { struct iwl_rxq rxq; - struct iwl_rb_allocator rba; + struct work_struct rx_replenish; struct iwl_trans *trans; struct iwl_drv *drv; diff --git a/drivers/net/wireless/iwlwifi/pcie/rx.c b/drivers/net/wireless/iwlwifi/pcie/rx.c index a3fbaa0ef5e0..adad8d0fae7f 100644 --- a/drivers/net/wireless/iwlwifi/pcie/rx.c +++ b/drivers/net/wireless/iwlwifi/pcie/rx.c @@ -1,7 +1,7 @@ /****************************************************************************** * * Copyright(c) 2003 - 2014 Intel Corporation. All rights reserved. - * Copyright(c) 2013 - 2015 Intel Mobile Communications GmbH + * Copyright(c) 2013 - 2014 Intel Mobile Communications GmbH * * Portions of this file are derived from the ipw3945 project, as well * as portions of the ieee80211 subsystem header files. @@ -74,29 +74,16 @@ * resets the Rx queue buffers with new memory. * * The management in the driver is as follows: - * + A list of pre-allocated RBDs is stored in iwl->rxq->rx_free. - * When the interrupt handler is called, the request is processed. - * The page is either stolen - transferred to the upper layer - * or reused - added immediately to the iwl->rxq->rx_free list. - * + When the page is stolen - the driver updates the matching queue's used - * count, detaches the RBD and transfers it to the queue used list. - * When there are two used RBDs - they are transferred to the allocator empty - * list. Work is then scheduled for the allocator to start allocating - * eight buffers. - * When there are another 6 used RBDs - they are transferred to the allocator - * empty list and the driver tries to claim the pre-allocated buffers and - * add them to iwl->rxq->rx_free. If it fails - it continues to claim them - * until ready. - * When there are 8+ buffers in the free list - either from allocation or from - * 8 reused unstolen pages - restock is called to update the FW and indexes. - * + In order to make sure the allocator always has RBDs to use for allocation - * the allocator has initial pool in the size of num_queues*(8-2) - the - * maximum missing RBDs per allocation request (request posted with 2 - * empty RBDs, there is no guarantee when the other 6 RBDs are supplied). - * The queues supplies the recycle of the rest of the RBDs. + * + A list of pre-allocated SKBs is stored in iwl->rxq->rx_free. When + * iwl->rxq->free_count drops to or below RX_LOW_WATERMARK, work is scheduled + * to replenish the iwl->rxq->rx_free. + * + In iwl_pcie_rx_replenish (scheduled) if 'processed' != 'read' then the + * iwl->rxq is replenished and the READ INDEX is updated (updating the + * 'processed' and 'read' driver indexes as well) * + A received packet is processed and handed to the kernel network stack, * detached from the iwl->rxq. The driver 'processed' index is updated. - * + If there are no allocated buffers in iwl->rxq->rx_free, + * + The Host/Firmware iwl->rxq is replenished at irq thread time from the + * rx_free list. If there are no allocated buffers in iwl->rxq->rx_free, * the READ INDEX is not incremented and iwl->status(RX_STALLED) is set. * If there were enough free buffers and RX_STALLED is set it is cleared. * @@ -105,32 +92,18 @@ * * iwl_rxq_alloc() Allocates rx_free * iwl_pcie_rx_replenish() Replenishes rx_free list from rx_used, and calls - * iwl_pcie_rxq_restock. - * Used only during initialization. + * iwl_pcie_rxq_restock * iwl_pcie_rxq_restock() Moves available buffers from rx_free into Rx * queue, updates firmware pointers, and updates - * the WRITE index. - * iwl_pcie_rx_allocator() Background work for allocating pages. + * the WRITE index. If insufficient rx_free buffers + * are available, schedules iwl_pcie_rx_replenish * * -- enable interrupts -- * ISR - iwl_rx() Detach iwl_rx_mem_buffers from pool up to the * READ INDEX, detaching the SKB from the pool. * Moves the packet buffer from queue to rx_used. - * Posts and claims requests to the allocator. * Calls iwl_pcie_rxq_restock to refill any empty * slots. - * - * RBD life-cycle: - * - * Init: - * rxq.pool -> rxq.rx_used -> rxq.rx_free -> rxq.queue - * - * Regular Receive interrupt: - * Page Stolen: - * rxq.queue -> rxq.rx_used -> allocator.rbd_empty -> - * allocator.rbd_allocated -> rxq.rx_free -> rxq.queue - * Page not Stolen: - * rxq.queue -> rxq.rx_free -> rxq.queue * ... * */ @@ -267,6 +240,10 @@ static void iwl_pcie_rxq_restock(struct iwl_trans *trans) rxq->free_count--; } spin_unlock(&rxq->lock); + /* If the pre-allocated buffer pool is dropping low, schedule to + * refill it */ + if (rxq->free_count <= RX_LOW_WATERMARK) + schedule_work(&trans_pcie->rx_replenish); /* If we've added more space for the firmware to place data, tell it. * Increment device's write pointer in multiples of 8. */ @@ -277,44 +254,6 @@ static void iwl_pcie_rxq_restock(struct iwl_trans *trans) } } -/* - * iwl_pcie_rx_alloc_page - allocates and returns a page. - * - */ -static struct page *iwl_pcie_rx_alloc_page(struct iwl_trans *trans) -{ - struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); - struct iwl_rxq *rxq = &trans_pcie->rxq; - struct page *page; - gfp_t gfp_mask = GFP_KERNEL; - - if (rxq->free_count > RX_LOW_WATERMARK) - gfp_mask |= __GFP_NOWARN; - - if (trans_pcie->rx_page_order > 0) - gfp_mask |= __GFP_COMP; - - /* Alloc a new receive buffer */ - page = alloc_pages(gfp_mask, trans_pcie->rx_page_order); - if (!page) { - if (net_ratelimit()) - IWL_DEBUG_INFO(trans, "alloc_pages failed, order: %d\n", - trans_pcie->rx_page_order); - /* Issue an error if the hardware has consumed more than half - * of its free buffer list and we don't have enough - * pre-allocated buffers. -` */ - if (rxq->free_count <= RX_LOW_WATERMARK && - iwl_rxq_space(rxq) > (RX_QUEUE_SIZE / 2) && - net_ratelimit()) - IWL_CRIT(trans, - "Failed to alloc_pages with GFP_KERNEL. Only %u free buffers remaining.\n", - rxq->free_count); - return NULL; - } - return page; -} - /* * iwl_pcie_rxq_alloc_rbs - allocate a page for each used RBD * @@ -324,12 +263,13 @@ static struct page *iwl_pcie_rx_alloc_page(struct iwl_trans *trans) * iwl_pcie_rxq_restock. The latter function will update the HW to use the newly * allocated buffers. */ -static void iwl_pcie_rxq_alloc_rbs(struct iwl_trans *trans) +static void iwl_pcie_rxq_alloc_rbs(struct iwl_trans *trans, gfp_t priority) { struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); struct iwl_rxq *rxq = &trans_pcie->rxq; struct iwl_rx_mem_buffer *rxb; struct page *page; + gfp_t gfp_mask = priority; while (1) { spin_lock(&rxq->lock); @@ -339,10 +279,32 @@ static void iwl_pcie_rxq_alloc_rbs(struct iwl_trans *trans) } spin_unlock(&rxq->lock); + if (rxq->free_count > RX_LOW_WATERMARK) + gfp_mask |= __GFP_NOWARN; + + if (trans_pcie->rx_page_order > 0) + gfp_mask |= __GFP_COMP; + /* Alloc a new receive buffer */ - page = iwl_pcie_rx_alloc_page(trans); - if (!page) + page = alloc_pages(gfp_mask, trans_pcie->rx_page_order); + if (!page) { + if (net_ratelimit()) + IWL_DEBUG_INFO(trans, "alloc_pages failed, " + "order: %d\n", + trans_pcie->rx_page_order); + + if ((rxq->free_count <= RX_LOW_WATERMARK) && + net_ratelimit()) + IWL_CRIT(trans, "Failed to alloc_pages with %s." + "Only %u free buffers remaining.\n", + priority == GFP_ATOMIC ? + "GFP_ATOMIC" : "GFP_KERNEL", + rxq->free_count); + /* We don't reschedule replenish work here -- we will + * call the restock method and if it still needs + * more buffers it will schedule replenish */ return; + } spin_lock(&rxq->lock); @@ -393,7 +355,7 @@ static void iwl_pcie_rxq_free_rbs(struct iwl_trans *trans) lockdep_assert_held(&rxq->lock); - for (i = 0; i < RX_QUEUE_SIZE; i++) { + for (i = 0; i < RX_FREE_BUFFERS + RX_QUEUE_SIZE; i++) { if (!rxq->pool[i].page) continue; dma_unmap_page(trans->dev, rxq->pool[i].page_dma, @@ -410,144 +372,32 @@ static void iwl_pcie_rxq_free_rbs(struct iwl_trans *trans) * When moving to rx_free an page is allocated for the slot. * * Also restock the Rx queue via iwl_pcie_rxq_restock. - * This is called only during initialization + * This is called as a scheduled work item (except for during initialization) */ -static void iwl_pcie_rx_replenish(struct iwl_trans *trans) +static void iwl_pcie_rx_replenish(struct iwl_trans *trans, gfp_t gfp) { - iwl_pcie_rxq_alloc_rbs(trans); + iwl_pcie_rxq_alloc_rbs(trans, gfp); iwl_pcie_rxq_restock(trans); } -/* - * iwl_pcie_rx_allocator - Allocates pages in the background for RX queues - * - * Allocates for each received request 8 pages - * Called as a scheduled work item. - */ -static void iwl_pcie_rx_allocator(struct iwl_trans *trans) -{ - struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); - struct iwl_rb_allocator *rba = &trans_pcie->rba; - - while (atomic_read(&rba->req_pending)) { - int i; - struct list_head local_empty; - struct list_head local_allocated; - - INIT_LIST_HEAD(&local_allocated); - spin_lock(&rba->lock); - /* swap out the entire rba->rbd_empty to a local list */ - list_replace_init(&rba->rbd_empty, &local_empty); - spin_unlock(&rba->lock); - - for (i = 0; i < RX_CLAIM_REQ_ALLOC;) { - struct iwl_rx_mem_buffer *rxb; - struct page *page; - - /* List should never be empty - each reused RBD is - * returned to the list, and initial pool covers any - * possible gap between the time the page is allocated - * to the time the RBD is added. - */ - BUG_ON(list_empty(&local_empty)); - /* Get the first rxb from the rbd list */ - rxb = list_first_entry(&local_empty, - struct iwl_rx_mem_buffer, list); - BUG_ON(rxb->page); - - /* Alloc a new receive buffer */ - page = iwl_pcie_rx_alloc_page(trans); - if (!page) - continue; - rxb->page = page; - - /* Get physical address of the RB */ - rxb->page_dma = dma_map_page(trans->dev, page, 0, - PAGE_SIZE << trans_pcie->rx_page_order, - DMA_FROM_DEVICE); - if (dma_mapping_error(trans->dev, rxb->page_dma)) { - rxb->page = NULL; - __free_pages(page, trans_pcie->rx_page_order); - continue; - } - /* dma address must be no more than 36 bits */ - BUG_ON(rxb->page_dma & ~DMA_BIT_MASK(36)); - /* and also 256 byte aligned! */ - BUG_ON(rxb->page_dma & DMA_BIT_MASK(8)); - - /* move the allocated entry to the out list */ - list_move(&rxb->list, &local_allocated); - i++; - } - - spin_lock(&rba->lock); - /* add the allocated rbds to the allocator allocated list */ - list_splice_tail(&local_allocated, &rba->rbd_allocated); - /* add the unused rbds back to the allocator empty list */ - list_splice_tail(&local_empty, &rba->rbd_empty); - spin_unlock(&rba->lock); - - atomic_dec(&rba->req_pending); - atomic_inc(&rba->req_ready); - } -} - -/* - * iwl_pcie_rx_allocator_get - Returns the pre-allocated pages -.* -.* Called by queue when the queue posted allocation request and - * has freed 8 RBDs in order to restock itself. - */ -static int iwl_pcie_rx_allocator_get(struct iwl_trans *trans, - struct iwl_rx_mem_buffer - *out[RX_CLAIM_REQ_ALLOC]) -{ - struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); - struct iwl_rb_allocator *rba = &trans_pcie->rba; - int i; - - if (atomic_dec_return(&rba->req_ready) < 0) { - atomic_inc(&rba->req_ready); - IWL_DEBUG_RX(trans, - "Allocation request not ready, pending requests = %d\n", - atomic_read(&rba->req_pending)); - return -ENOMEM; - } - - spin_lock(&rba->lock); - for (i = 0; i < RX_CLAIM_REQ_ALLOC; i++) { - /* Get next free Rx buffer, remove it from free list */ - out[i] = list_first_entry(&rba->rbd_allocated, - struct iwl_rx_mem_buffer, list); - list_del(&out[i]->list); - } - spin_unlock(&rba->lock); - - return 0; -} - -static void iwl_pcie_rx_allocator_work(struct work_struct *data) +static void iwl_pcie_rx_replenish_work(struct work_struct *data) { - struct iwl_rb_allocator *rba_p = - container_of(data, struct iwl_rb_allocator, rx_alloc); struct iwl_trans_pcie *trans_pcie = - container_of(rba_p, struct iwl_trans_pcie, rba); + container_of(data, struct iwl_trans_pcie, rx_replenish); - iwl_pcie_rx_allocator(trans_pcie->trans); + iwl_pcie_rx_replenish(trans_pcie->trans, GFP_KERNEL); } static int iwl_pcie_rx_alloc(struct iwl_trans *trans) { struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); struct iwl_rxq *rxq = &trans_pcie->rxq; - struct iwl_rb_allocator *rba = &trans_pcie->rba; struct device *dev = trans->dev; memset(&trans_pcie->rxq, 0, sizeof(trans_pcie->rxq)); spin_lock_init(&rxq->lock); - spin_lock_init(&rba->lock); if (WARN_ON(rxq->bd || rxq->rb_stts)) return -EINVAL; @@ -637,49 +487,15 @@ static void iwl_pcie_rx_init_rxb_lists(struct iwl_rxq *rxq) INIT_LIST_HEAD(&rxq->rx_free); INIT_LIST_HEAD(&rxq->rx_used); rxq->free_count = 0; - rxq->used_count = 0; - for (i = 0; i < RX_QUEUE_SIZE; i++) + for (i = 0; i < RX_FREE_BUFFERS + RX_QUEUE_SIZE; i++) list_add(&rxq->pool[i].list, &rxq->rx_used); } -static void iwl_pcie_rx_init_rba(struct iwl_rb_allocator *rba) -{ - int i; - - lockdep_assert_held(&rba->lock); - - INIT_LIST_HEAD(&rba->rbd_allocated); - INIT_LIST_HEAD(&rba->rbd_empty); - - for (i = 0; i < RX_POOL_SIZE; i++) - list_add(&rba->pool[i].list, &rba->rbd_empty); -} - -static void iwl_pcie_rx_free_rba(struct iwl_trans *trans) -{ - struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); - struct iwl_rb_allocator *rba = &trans_pcie->rba; - int i; - - lockdep_assert_held(&rba->lock); - - for (i = 0; i < RX_POOL_SIZE; i++) { - if (!rba->pool[i].page) - continue; - dma_unmap_page(trans->dev, rba->pool[i].page_dma, - PAGE_SIZE << trans_pcie->rx_page_order, - DMA_FROM_DEVICE); - __free_pages(rba->pool[i].page, trans_pcie->rx_page_order); - rba->pool[i].page = NULL; - } -} - int iwl_pcie_rx_init(struct iwl_trans *trans) { struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); struct iwl_rxq *rxq = &trans_pcie->rxq; - struct iwl_rb_allocator *rba = &trans_pcie->rba; int i, err; if (!rxq->bd) { @@ -687,21 +503,11 @@ int iwl_pcie_rx_init(struct iwl_trans *trans) if (err) return err; } - if (!rba->alloc_wq) - rba->alloc_wq = alloc_workqueue("rb_allocator", - WQ_HIGHPRI | WQ_UNBOUND, 1); - INIT_WORK(&rba->rx_alloc, iwl_pcie_rx_allocator_work); - - spin_lock(&rba->lock); - atomic_set(&rba->req_pending, 0); - atomic_set(&rba->req_ready, 0); - /* free all first - we might be reconfigured for a different size */ - iwl_pcie_rx_free_rba(trans); - iwl_pcie_rx_init_rba(rba); - spin_unlock(&rba->lock); spin_lock(&rxq->lock); + INIT_WORK(&trans_pcie->rx_replenish, iwl_pcie_rx_replenish_work); + /* free all first - we might be reconfigured for a different size */ iwl_pcie_rxq_free_rbs(trans); iwl_pcie_rx_init_rxb_lists(rxq); @@ -716,7 +522,7 @@ int iwl_pcie_rx_init(struct iwl_trans *trans) memset(rxq->rb_stts, 0, sizeof(*rxq->rb_stts)); spin_unlock(&rxq->lock); - iwl_pcie_rx_replenish(trans); + iwl_pcie_rx_replenish(trans, GFP_KERNEL); iwl_pcie_rx_hw_init(trans, rxq); @@ -731,7 +537,6 @@ void iwl_pcie_rx_free(struct iwl_trans *trans) { struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); struct iwl_rxq *rxq = &trans_pcie->rxq; - struct iwl_rb_allocator *rba = &trans_pcie->rba; /*if rxq->bd is NULL, it means that nothing has been allocated, * exit now */ @@ -740,15 +545,7 @@ void iwl_pcie_rx_free(struct iwl_trans *trans) return; } - cancel_work_sync(&rba->rx_alloc); - if (rba->alloc_wq) { - destroy_workqueue(rba->alloc_wq); - rba->alloc_wq = NULL; - } - - spin_lock(&rba->lock); - iwl_pcie_rx_free_rba(trans); - spin_unlock(&rba->lock); + cancel_work_sync(&trans_pcie->rx_replenish); spin_lock(&rxq->lock); iwl_pcie_rxq_free_rbs(trans); @@ -769,43 +566,6 @@ void iwl_pcie_rx_free(struct iwl_trans *trans) rxq->rb_stts = NULL; } -/* - * iwl_pcie_rx_reuse_rbd - Recycle used RBDs - * - * Called when a RBD can be reused. The RBD is transferred to the allocator. - * When there are 2 empty RBDs - a request for allocation is posted - */ -static void iwl_pcie_rx_reuse_rbd(struct iwl_trans *trans, - struct iwl_rx_mem_buffer *rxb, - struct iwl_rxq *rxq) -{ - struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); - struct iwl_rb_allocator *rba = &trans_pcie->rba; - - /* Count the used RBDs */ - rxq->used_count++; - - /* Move the RBD to the used list, will be moved to allocator in batches - * before claiming or posting a request*/ - list_add_tail(&rxb->list, &rxq->rx_used); - - /* If we have RX_POST_REQ_ALLOC new released rx buffers - - * issue a request for allocator. Modulo RX_CLAIM_REQ_ALLOC is - * used for the case we failed to claim RX_CLAIM_REQ_ALLOC, - * after but we still need to post another request. - */ - if ((rxq->used_count % RX_CLAIM_REQ_ALLOC) == RX_POST_REQ_ALLOC) { - /* Move the 2 RBDs to the allocator ownership. - Allocator has another 6 from pool for the request completion*/ - spin_lock(&rba->lock); - list_splice_tail_init(&rxq->rx_used, &rba->rbd_empty); - spin_unlock(&rba->lock); - - atomic_inc(&rba->req_pending); - queue_work(rba->alloc_wq, &rba->rx_alloc); - } -} - static void iwl_pcie_rx_handle_rb(struct iwl_trans *trans, struct iwl_rx_mem_buffer *rxb) { @@ -928,13 +688,13 @@ static void iwl_pcie_rx_handle_rb(struct iwl_trans *trans, */ __free_pages(rxb->page, trans_pcie->rx_page_order); rxb->page = NULL; - iwl_pcie_rx_reuse_rbd(trans, rxb, rxq); + list_add_tail(&rxb->list, &rxq->rx_used); } else { list_add_tail(&rxb->list, &rxq->rx_free); rxq->free_count++; } } else - iwl_pcie_rx_reuse_rbd(trans, rxb, rxq); + list_add_tail(&rxb->list, &rxq->rx_used); } /* @@ -944,7 +704,10 @@ static void iwl_pcie_rx_handle(struct iwl_trans *trans) { struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); struct iwl_rxq *rxq = &trans_pcie->rxq; - u32 r, i, j; + u32 r, i; + u8 fill_rx = 0; + u32 count = 8; + int total_empty; restart: spin_lock(&rxq->lock); @@ -957,6 +720,14 @@ restart: if (i == r) IWL_DEBUG_RX(trans, "HW = SW = %d\n", r); + /* calculate total frames need to be restock after handling RX */ + total_empty = r - rxq->write_actual; + if (total_empty < 0) + total_empty += RX_QUEUE_SIZE; + + if (total_empty > (RX_QUEUE_SIZE / 2)) + fill_rx = 1; + while (i != r) { struct iwl_rx_mem_buffer *rxb; @@ -968,48 +739,29 @@ restart: iwl_pcie_rx_handle_rb(trans, rxb); i = (i + 1) & RX_QUEUE_MASK; - - /* If we have RX_CLAIM_REQ_ALLOC released rx buffers - - * try to claim the pre-allocated buffers from the allocator */ - if (rxq->used_count >= RX_CLAIM_REQ_ALLOC) { - struct iwl_rb_allocator *rba = &trans_pcie->rba; - struct iwl_rx_mem_buffer *out[RX_CLAIM_REQ_ALLOC]; - - /* Add the remaining 6 empty RBDs for allocator use */ - spin_lock(&rba->lock); - list_splice_tail_init(&rxq->rx_used, &rba->rbd_empty); - spin_unlock(&rba->lock); - - /* If not ready - continue, will try to reclaim later. - * No need to reschedule work - allocator exits only on - * success */ - if (!iwl_pcie_rx_allocator_get(trans, out)) { - /* If success - then RX_CLAIM_REQ_ALLOC - * buffers were retrieved and should be added - * to free list */ - rxq->used_count -= RX_CLAIM_REQ_ALLOC; - for (j = 0; j < RX_CLAIM_REQ_ALLOC; j++) { - list_add_tail(&out[j]->list, - &rxq->rx_free); - rxq->free_count++; - } + /* If there are a lot of unused frames, + * restock the Rx queue so ucode wont assert. */ + if (fill_rx) { + count++; + if (count >= 8) { + rxq->read = i; + spin_unlock(&rxq->lock); + iwl_pcie_rx_replenish(trans, GFP_ATOMIC); + count = 0; + goto restart; } } - /* handle restock for two cases: - * - we just pulled buffers from the allocator - * - we have 8+ unstolen pages accumulated */ - if (rxq->free_count >= RX_CLAIM_REQ_ALLOC) { - rxq->read = i; - spin_unlock(&rxq->lock); - iwl_pcie_rxq_restock(trans); - goto restart; - } } /* Backtrack one entry */ rxq->read = i; spin_unlock(&rxq->lock); + if (fill_rx) + iwl_pcie_rx_replenish(trans, GFP_ATOMIC); + else + iwl_pcie_rxq_restock(trans); + if (trans_pcie->napi.poll) napi_gro_flush(&trans_pcie->napi, false); } -- 2.20.1