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Commit 255ba065 authored by Emmanuel Grumbach's avatar Emmanuel Grumbach
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Revert "iwlwifi: pcie: New RBD allocation model" 

This reverts commit 5f175703.

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: default avatarEmmanuel Grumbach <emmanuel.grumbach@intel.com>
parent 8465fe6a
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Inline Side-by-side
Showing with 97 additions and 374 deletions
drivers/net/wireless/iwlwifi/iwl-fh.h
View file @ 255ba065
......@@ -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
......
drivers/net/wireless/iwlwifi/pcie/internal.h
View file @ 255ba065
......@@ -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;
......
drivers/net/wireless/iwlwifi/pcie/rx.c
View file @ 255ba065
/******************************************************************************
*
* 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 @@ static void iwl_pcie_rx_handle(struct iwl_trans *trans)
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 @@ static void iwl_pcie_rx_handle(struct iwl_trans *trans)
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++;
}
}
}
/* 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) {
/* 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_rxq_restock(trans);
iwl_pcie_rx_replenish(trans, GFP_ATOMIC);
count = 0;
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);
}
......
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