/*
* iwl_pcie_rx_alloc_page - allocates and returns a page.
*
*/
static struct page *iwl_pcie_rx_alloc_page(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 page *page;
gfp_t gfp_mask = priority;
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_restock - refill RX queue from pre-allocated pool
*
* If there are slots in the RX queue that need to be restocked,
* and we have free pre-allocated buffers, fill the ranks as much
* as we can, pulling from rx_free.
*
* This moves the 'write' index forward to catch up with 'processed', and
* also updates the memory address in the firmware to reference the new
* target buffer.
*/
static void iwl_pcie_rxq_restock(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;
unsigned long flags;
/*
* If the device isn't enabled - not need to try to add buffers...
* This can happen when we stop the device and still have an interrupt
* pending. We stop the APM before we sync the interrupts because we
* have to (see comment there). On the other hand, since the APM is
* stopped, we cannot access the HW (in particular not prph).
* So don't try to restock if the APM has been already stopped.
*/
if (!test_bit(STATUS_DEVICE_ENABLED, &trans_pcie->status))
return;
spin_lock_irqsave(&rxq->lock, flags);
while ((iwl_rxq_space(rxq) > 0) && (rxq->free_count)) {
/* The overwritten rxb must be a used one */
rxb = rxq->queue[rxq->write];
BUG_ON(rxb && rxb->page);
/* Get next free Rx buffer, remove from free list */
rxb = list_first_entry(&rxq->rx_free, struct iwl_rx_mem_buffer,
list);
list_del(&rxb->list);
/* Point to Rx buffer via next RBD in circular buffer */
rxq->bd[rxq->write] = iwl_pcie_dma_addr2rbd_ptr(rxb->page_dma);
rxq->queue[rxq->write] = rxb;
rxq->write = (rxq->write + 1) & RX_QUEUE_MASK;
rxq->free_count--;
}
spin_unlock_irqrestore(&rxq->lock, flags);
/* 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. */
if (rxq->write_actual != (rxq->write & ~0x7)) {
spin_lock_irqsave(&rxq->lock, flags);
rxq->need_update = 1;
spin_unlock_irqrestore(&rxq->lock, flags);
iwl_pcie_rxq_inc_wr_ptr(trans, rxq);
}
}
