/******************************************************************************
*
* Copyright(c) 2003 - 2014 Intel Corporation. All rights reserved.
- * Copyright(c) 2013 - 2014 Intel Mobile Communications GmbH
+ * Copyright(c) 2013 - 2015 Intel Mobile Communications GmbH
*
* Portions of this file are derived from the ipw3945 project, as well
* as portions of the ieee80211 subsystem header files.
* resets the Rx queue buffers with new memory.
*
* The management in the driver is as follows:
- * + 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 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 received packet is processed and handed to the kernel network stack,
* detached from the iwl->rxq. The driver 'processed' index is updated.
- * + 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,
+ * + 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.
*
*
* iwl_rxq_alloc() Allocates rx_free
* iwl_pcie_rx_replenish() Replenishes rx_free list from rx_used, and calls
- * iwl_pcie_rxq_restock
+ * iwl_pcie_rxq_restock.
+ * Used only during initialization.
* iwl_pcie_rxq_restock() Moves available buffers from rx_free into Rx
* queue, updates firmware pointers, and updates
- * the WRITE index. If insufficient rx_free buffers
- * are available, schedules iwl_pcie_rx_replenish
+ * the WRITE index.
+ * iwl_pcie_rx_allocator() Background work for allocating pages.
*
* -- 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
* ...
*
*/
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. */
}
}
+/*
+ * 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
*
* 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, gfp_t priority)
+static void iwl_pcie_rxq_alloc_rbs(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_rx_mem_buffer *rxb;
struct page *page;
- gfp_t gfp_mask = priority;
while (1) {
spin_lock(&rxq->lock);
}
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 = 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 */
+ page = iwl_pcie_rx_alloc_page(trans);
+ if (!page)
return;
- }
spin_lock(&rxq->lock);
lockdep_assert_held(&rxq->lock);
- for (i = 0; i < RX_FREE_BUFFERS + RX_QUEUE_SIZE; i++) {
+ for (i = 0; i < RX_QUEUE_SIZE; i++) {
if (!rxq->pool[i].page)
continue;
dma_unmap_page(trans->dev, rxq->pool[i].page_dma,
* 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 as a scheduled work item (except for during initialization)
+ * This is called only during initialization
*/
-static void iwl_pcie_rx_replenish(struct iwl_trans *trans, gfp_t gfp)
+static void iwl_pcie_rx_replenish(struct iwl_trans *trans)
{
- iwl_pcie_rxq_alloc_rbs(trans, gfp);
+ iwl_pcie_rxq_alloc_rbs(trans);
iwl_pcie_rxq_restock(trans);
}
-static void iwl_pcie_rx_replenish_work(struct work_struct *data)
+/*
+ * 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)
{
+ struct iwl_rb_allocator *rba_p =
+ container_of(data, struct iwl_rb_allocator, rx_alloc);
struct iwl_trans_pcie *trans_pcie =
- container_of(data, struct iwl_trans_pcie, rx_replenish);
+ container_of(rba_p, struct iwl_trans_pcie, rba);
- iwl_pcie_rx_replenish(trans_pcie->trans, GFP_KERNEL);
+ iwl_pcie_rx_allocator(trans_pcie->trans);
}
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;
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_FREE_BUFFERS + RX_QUEUE_SIZE; i++)
+ for (i = 0; i < 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) {
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);
memset(rxq->rb_stts, 0, sizeof(*rxq->rb_stts));
spin_unlock(&rxq->lock);
- iwl_pcie_rx_replenish(trans, GFP_KERNEL);
+ iwl_pcie_rx_replenish(trans);
iwl_pcie_rx_hw_init(trans, rxq);
{
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 */
return;
}
- cancel_work_sync(&trans_pcie->rx_replenish);
+ 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);
spin_lock(&rxq->lock);
iwl_pcie_rxq_free_rbs(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)
{
*/
__free_pages(rxb->page, trans_pcie->rx_page_order);
rxb->page = NULL;
- list_add_tail(&rxb->list, &rxq->rx_used);
+ iwl_pcie_rx_reuse_rbd(trans, rxb, rxq);
} else {
list_add_tail(&rxb->list, &rxq->rx_free);
rxq->free_count++;
}
} else
- list_add_tail(&rxb->list, &rxq->rx_used);
+ iwl_pcie_rx_reuse_rbd(trans, rxb, rxq);
}
/*
{
struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
struct iwl_rxq *rxq = &trans_pcie->rxq;
- u32 r, i;
- u8 fill_rx = 0;
- u32 count = 8;
- int total_empty;
+ u32 r, i, j;
restart:
spin_lock(&rxq->lock);
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;
iwl_pcie_rx_handle_rb(trans, rxb);
i = (i + 1) & RX_QUEUE_MASK;
- /* 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;
+
+ /* 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) {
+ 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);
}
projects / mirror_ubuntu-disco-kernel.git / commitdiff