Add helpers to register/deregister individual RX queues and scale queue count up or down while the netdev stays up. Surviving queues keep PHYP handles, buffer pools, and IRQ state across resize.
Signed-off-by: Mingming Cao <[email protected]> Reviewed-by: Dave Marquardt <[email protected]> --- drivers/net/ethernet/ibm/ibmveth.c | 406 ++++++++++++++++++++++++++++- 1 file changed, 401 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/ibm/ibmveth.c b/drivers/net/ethernet/ibm/ibmveth.c index ecc472ee8f71..ac4d89a66a8d 100644 --- a/drivers/net/ethernet/ibm/ibmveth.c +++ b/drivers/net/ethernet/ibm/ibmveth.c @@ -589,6 +589,54 @@ ibmveth_cleanup_rx_interrupts(struct ibmveth_adapter *adapter) adapter->queue_irq[0] = 0; } +/** + * ibmveth_setup_single_rx_interrupt - Setup interrupt for a single RX queue + * @adapter: ibmveth adapter structure + * @queue_idx: Queue index to setup + * + * Registers the IRQ handler for one queue. Used during incremental + * scale-up when adding new RX queues; the caller enables NAPI via + * napi_enable() after ibmveth_enable_irq(). + * + * Return: 0 on success, negative error code on failure + */ +static int +ibmveth_setup_single_rx_interrupt(struct ibmveth_adapter *adapter, + int queue_idx) +{ + struct net_device *netdev = adapter->netdev; + int rc; + + rc = request_irq(adapter->queue_irq[queue_idx], ibmveth_interrupt, + 0, netdev->name, &adapter->napi[queue_idx]); + if (rc) { + netdev_err(netdev, "request_irq() failed for queue %d: %d\n", + queue_idx, rc); + return rc; + } + + netdev_dbg(netdev, "Setup IRQ %d for queue %d\n", + adapter->queue_irq[queue_idx], queue_idx); + return 0; +} + +/** + * ibmveth_cleanup_single_rx_interrupt - Cleanup interrupt for a single RX queue + * @adapter: ibmveth adapter structure + * @queue_idx: Queue index to cleanup + * + * Frees the IRQ handler for one queue. Used during incremental scale-down. + */ +static void +ibmveth_cleanup_single_rx_interrupt(struct ibmveth_adapter *adapter, + int queue_idx) +{ + if (adapter->queue_irq[queue_idx]) { + free_irq(adapter->queue_irq[queue_idx], &adapter->napi[queue_idx]); + netdev_dbg(adapter->netdev, "Freed IRQ for queue %d\n", queue_idx); + } +} + /* setup the initial settings for a buffer pool */ static void ibmveth_init_buffer_pool(struct ibmveth_buff_pool *pool, u32 pool_index, u32 pool_size, @@ -897,18 +945,22 @@ static void ibmveth_replenish_task(struct ibmveth_adapter *adapter, unsigned long flags; int i; - if (queue_index >= adapter->num_rx_queues) - return; - adapter->replenish_task_cycles++; + if (queue_index >= adapter->num_rx_queues) { + netdev_dbg(adapter->netdev, + "Skipping replenish for freed queue %d (num_queues=%d)\n", + queue_index, adapter->num_rx_queues); + return; + } + spin_lock_irqsave(&rxq->replenish_lock, flags); for (i = (IBMVETH_NUM_BUFF_POOLS - 1); i >= 0; i--) { struct ibmveth_buff_pool *pool = &adapter->rx_buff_pool[queue_index][i]; - if (pool->active && + if (pool->active && pool->free_map && (atomic_read(&pool->available) < pool->threshold)) ibmveth_replenish_buffer_pool(adapter, pool, queue_index); @@ -1080,6 +1132,138 @@ static void ibmveth_free_buffer_pools(struct ibmveth_adapter *adapter) adapter->num_rx_queues); } +/** + * ibmveth_alloc_single_rx_queue - Allocate resources for a single RX queue + * @adapter: ibmveth adapter structure + * @queue_idx: Queue index to allocate + * @rxq_entries: Number of RX queue entries + * + * Allocates buffer list, RX queue, and per-queue buffer pools for one queue. + * Used during incremental scale-up without affecting existing queues. + * + * Return: 0 on success, negative error code on failure + */ +static int +ibmveth_alloc_single_rx_queue(struct ibmveth_adapter *adapter, int queue_idx, + int rxq_entries) +{ + struct device *dev = &adapter->vdev->dev; + struct net_device *netdev = adapter->netdev; + int i, rc = -ENOMEM; + + adapter->buffer_list_addr[queue_idx] = (void *)get_zeroed_page(GFP_KERNEL); + if (!adapter->buffer_list_addr[queue_idx]) { + netdev_err(netdev, "unable to allocate buffer list for queue %d\n", + queue_idx); + return -ENOMEM; + } + + adapter->rx_queue[queue_idx].queue_len = + sizeof(struct ibmveth_rx_q_entry) * rxq_entries; + adapter->rx_queue[queue_idx].queue_addr = + dma_alloc_coherent(dev, adapter->rx_queue[queue_idx].queue_len, + &adapter->rx_queue[queue_idx].queue_dma, + GFP_KERNEL); + if (!adapter->rx_queue[queue_idx].queue_addr) { + netdev_err(netdev, "unable to allocate RX queue for queue %d\n", + queue_idx); + goto out_free_buflist; + } + + adapter->buffer_list_dma[queue_idx] = + dma_map_single(dev, adapter->buffer_list_addr[queue_idx], + 4096, DMA_BIDIRECTIONAL); + if (dma_mapping_error(dev, adapter->buffer_list_dma[queue_idx])) { + netdev_err(netdev, "unable to map buffer list for queue %d\n", + queue_idx); + goto out_free_rxq; + } + + for (i = 0; i < IBMVETH_NUM_BUFF_POOLS; i++) { + adapter->rx_buff_pool[queue_idx][i].size = + adapter->rx_buff_pool[0][i].size; + adapter->rx_buff_pool[queue_idx][i].buff_size = + adapter->rx_buff_pool[0][i].buff_size; + adapter->rx_buff_pool[queue_idx][i].threshold = + adapter->rx_buff_pool[0][i].threshold; + adapter->rx_buff_pool[queue_idx][i].active = + adapter->rx_buff_pool[0][i].active; + } + + rc = ibmveth_alloc_queue_buffer_pools(adapter, queue_idx); + if (rc) { + netdev_err(netdev, + "Failed to allocate buffer pools for queue %d\n", + queue_idx); + goto out_unmap_buflist; + } + + adapter->rx_queue[queue_idx].index = 0; + adapter->rx_queue[queue_idx].num_slots = rxq_entries; + adapter->rx_queue[queue_idx].toggle = 1; + spin_lock_init(&adapter->rx_queue[queue_idx].replenish_lock); + + netdev_dbg(netdev, + "Allocated queue %d: buffer_list @ %p (DMA: 0x%llx), rx_queue @ %p (DMA: 0x%llx), %d entries\n", + queue_idx, adapter->buffer_list_addr[queue_idx], + (unsigned long long)adapter->buffer_list_dma[queue_idx], + adapter->rx_queue[queue_idx].queue_addr, + (unsigned long long)adapter->rx_queue[queue_idx].queue_dma, + rxq_entries); + + return 0; + +out_unmap_buflist: + dma_unmap_single(dev, adapter->buffer_list_dma[queue_idx], + 4096, DMA_BIDIRECTIONAL); + adapter->buffer_list_dma[queue_idx] = 0; +out_free_rxq: + dma_free_coherent(dev, adapter->rx_queue[queue_idx].queue_len, + adapter->rx_queue[queue_idx].queue_addr, + adapter->rx_queue[queue_idx].queue_dma); + adapter->rx_queue[queue_idx].queue_addr = NULL; +out_free_buflist: + free_page((unsigned long)adapter->buffer_list_addr[queue_idx]); + adapter->buffer_list_addr[queue_idx] = NULL; + return rc; +} + +/** + * ibmveth_free_single_rx_queue - Free resources for a single RX queue + * @adapter: ibmveth adapter structure + * @queue_idx: Queue index to free + * + * Frees buffer list, RX queue, and per-queue buffer pools for one queue. + * Used during incremental scale-down without affecting remaining queues. + */ +static void +ibmveth_free_single_rx_queue(struct ibmveth_adapter *adapter, int queue_idx) +{ + struct device *dev = &adapter->vdev->dev; + + ibmveth_free_queue_buffer_pools(adapter, queue_idx); + + if (adapter->buffer_list_dma[queue_idx]) { + dma_unmap_single(dev, adapter->buffer_list_dma[queue_idx], + 4096, DMA_BIDIRECTIONAL); + adapter->buffer_list_dma[queue_idx] = 0; + } + + if (adapter->rx_queue[queue_idx].queue_addr) { + dma_free_coherent(dev, adapter->rx_queue[queue_idx].queue_len, + adapter->rx_queue[queue_idx].queue_addr, + adapter->rx_queue[queue_idx].queue_dma); + adapter->rx_queue[queue_idx].queue_addr = NULL; + } + + if (adapter->buffer_list_addr[queue_idx]) { + free_page((unsigned long)adapter->buffer_list_addr[queue_idx]); + adapter->buffer_list_addr[queue_idx] = NULL; + } + + netdev_dbg(adapter->netdev, "Freed queue %d resources\n", queue_idx); +} + /** * ibmveth_remove_buffer_from_pool - remove a buffer from a pool * @adapter: adapter instance @@ -1192,6 +1376,49 @@ static int ibmveth_rxq_harvest_buffer(struct ibmveth_adapter *adapter, return 0; } +/** + * ibmveth_drain_rx_queue - Drain pending buffers from an RX queue + * @adapter: ibmveth adapter structure + * @queue_index: Queue index to drain + * + * Recycles all pending buffers back to the per-queue buffer pools. + * Must be called with NAPI disabled for this queue. + * + * Return: Number of buffers drained + */ +static int +ibmveth_drain_rx_queue(struct ibmveth_adapter *adapter, int queue_index) +{ + struct net_device *netdev = adapter->netdev; + int drained = 0; + int limit = adapter->rx_queue[queue_index].num_slots; + int rc; + + netdev_dbg(netdev, "Draining RX queue %d (limit: %d slots)\n", + queue_index, limit); + + while (drained < limit && + ibmveth_rxq_pending_buffer(adapter, queue_index)) { + rc = ibmveth_rxq_harvest_buffer(adapter, queue_index, true); + if (rc) { + netdev_err(netdev, + "Failed to harvest buffer from queue %d during drain: %d\n", + queue_index, rc); + break; + } + drained++; + } + + if (drained > 0) + netdev_dbg(netdev, "Drained %d buffer(s) from RX queue %d\n", + drained, queue_index); + else + netdev_dbg(netdev, "No buffers to drain from RX queue %d\n", + queue_index); + + return drained; +} + static void ibmveth_free_tx_ltb(struct ibmveth_adapter *adapter, int idx) { dma_unmap_single(&adapter->vdev->dev, adapter->tx_ltb_dma[idx], @@ -1459,7 +1686,7 @@ ibmveth_register_single_rx_queue(struct ibmveth_adapter *adapter, * the IRQ mapping for subordinate queues. Queue 0 is freed only through * ibmveth_free_all_queues() (H_FREE_LOGICAL_LAN). */ -static void __maybe_unused +static void ibmveth_deregister_single_rx_queue(struct ibmveth_adapter *adapter, int queue_idx) { @@ -1491,6 +1718,175 @@ ibmveth_deregister_single_rx_queue(struct ibmveth_adapter *adapter, netdev_dbg(adapter->netdev, "Deregistered queue %d\n", queue_idx); } +/** + * ibmveth_resize_rx_queues_incremental - Resize RX queue count incrementally + * @adapter: ibmveth adapter structure + * @new_count: Target number of RX queues + * @rxq_entries: Number of entries per RX queue + * + * Adds or removes RX queues without tearing down the entire adapter. + * Active queues continue receiving during scale-up; scale-down drains + * excess queues before deregistering them with the hypervisor. + * + * Return: 0 on success, negative error code on failure + */ +static int +ibmveth_resize_rx_queues_incremental(struct ibmveth_adapter *adapter, + int new_count, int rxq_entries) +{ + struct net_device *netdev = adapter->netdev; + u64 mac_address = ether_addr_to_u64(netdev->dev_addr); + int old_count = adapter->num_rx_queues; + int failed_queue; + int rc, i; + + if (old_count == new_count) { + netdev_dbg(netdev, "RX queue count unchanged (%d), nothing to do\n", + old_count); + return 0; + } + + if (new_count < 1 || new_count > IBMVETH_MAX_RX_QUEUES) { + netdev_err(netdev, "Invalid RX queue count %d (must be 1-%d)\n", + new_count, IBMVETH_MAX_RX_QUEUES); + return -EINVAL; + } + + netdev_info(netdev, "Incrementally resizing RX queues: %d to %d\n", + old_count, new_count); + + if (new_count > old_count) { + netdev_dbg(netdev, "Scale-up: adding queues %d-%d\n", + old_count, new_count - 1); + + for (i = old_count; i < new_count; i++) { + rc = ibmveth_alloc_single_rx_queue(adapter, i, rxq_entries); + if (rc) { + netdev_err(netdev, "Failed to allocate queue %d: %d\n", + i, rc); + goto cleanup_new_queues; + } + + rc = ibmveth_register_single_rx_queue(adapter, i, + mac_address); + if (rc) { + netdev_err(netdev, "Failed to register queue %d: %d\n", + i, rc); + ibmveth_free_single_rx_queue(adapter, i); + goto cleanup_new_queues; + } + + rc = ibmveth_setup_single_rx_interrupt(adapter, i); + if (rc) { + netdev_err(netdev, + "Failed to setup IRQ for queue %d: %d\n", + i, rc); + ibmveth_deregister_single_rx_queue(adapter, i); + ibmveth_free_single_rx_queue(adapter, i); + goto cleanup_new_queues; + } + + rc = ibmveth_enable_irq(adapter, i); + if (rc) { + netdev_err(netdev, + "Failed to enable IRQ for queue %d: %d\n", + i, rc); + ibmveth_cleanup_single_rx_interrupt(adapter, i); + ibmveth_deregister_single_rx_queue(adapter, i); + ibmveth_free_single_rx_queue(adapter, i); + goto cleanup_new_queues; + } + + napi_enable(&adapter->napi[i]); + } + + adapter->num_rx_queues = new_count; + + for (i = old_count; i < new_count; i++) + ibmveth_replenish_task(adapter, i); + + rc = netif_set_real_num_rx_queues(netdev, new_count); + if (rc) { + netdev_err(netdev, "Failed to set real RX queues to %d: %d\n", + new_count, rc); + goto cleanup_new_queues; + } + } else { + netdev_dbg(netdev, "Scale-down: removing queues %d-%d\n", + new_count, old_count - 1); + + for (i = new_count; i < old_count; i++) + napi_disable(&adapter->napi[i]); + + for (i = new_count; i < old_count; i++) + ibmveth_drain_rx_queue(adapter, i); + + synchronize_net(); + + rc = netif_set_real_num_rx_queues(netdev, new_count); + if (rc) { + netdev_err(netdev, "Failed to set real RX queues to %d: %d\n", + new_count, rc); + for (i = new_count; i < old_count; i++) + napi_enable(&adapter->napi[i]); + return rc; + } + + /* Disable hypervisor interrupts and wait for handlers to complete + * before updating num_rx_queues. + */ + for (i = new_count; i < old_count; i++) { + ibmveth_disable_irq(adapter, i); + synchronize_irq(adapter->queue_irq[i]); + } + + adapter->num_rx_queues = new_count; + + for (i = new_count; i < old_count; i++) { + ibmveth_cleanup_single_rx_interrupt(adapter, i); + ibmveth_deregister_single_rx_queue(adapter, i); + ibmveth_free_single_rx_queue(adapter, i); + } + } + + netdev_info(netdev, "Successfully resized to %d RX queues (incremental)\n", + adapter->num_rx_queues); + + if (firmware_has_feature(FW_FEATURE_CMO)) + vio_cmo_set_dev_desired(adapter->vdev, + ibmveth_get_desired_dma(adapter->vdev)); + + return 0; + +cleanup_new_queues: + failed_queue = i; + netdev_err(netdev, + "Scale-up failed at queue %d, cleaning up queues %d-%d\n", + failed_queue, old_count, failed_queue - 1); + for (i = old_count; i < failed_queue; i++) + napi_disable(&adapter->napi[i]); + + for (i = old_count; i < failed_queue; i++) + ibmveth_drain_rx_queue(adapter, i); + + synchronize_net(); + + for (i = old_count; i < failed_queue; i++) { + ibmveth_disable_irq(adapter, i); + synchronize_irq(adapter->queue_irq[i]); + } + + for (i = old_count; i < failed_queue; i++) { + ibmveth_cleanup_single_rx_interrupt(adapter, i); + ibmveth_deregister_single_rx_queue(adapter, i); + ibmveth_free_single_rx_queue(adapter, i); + } + adapter->num_rx_queues = old_count; + netdev_warn(netdev, "Keeping %d queues after scale-up failure\n", + old_count); + return rc; +} + /** * ibmveth_free_all_queues - Free all RX queues at once * @adapter: ibmveth adapter structure -- 2.39.3 (Apple Git-146)
