From f8ac0bfa7d7acefecfa18da8e27ff67adaefe45c Mon Sep 17 00:00:00 2001 From: Sukadev Bhattiprolu Date: Tue, 14 Sep 2021 20:52:57 -0700 Subject: ibmvnic: Reuse LTB when possible Reuse the long term buffer during a reset as long as its size has not changed. If the size has changed, free it and allocate a new one of the appropriate size. When we do this, alloc_long_term_buff() and reset_long_term_buff() become identical. Drop reset_long_term_buff(). Reviewed-by: Rick Lindsley Reviewed-by: Dany Madden Signed-off-by: Sukadev Bhattiprolu Signed-off-by: David S. Miller --- drivers/net/ethernet/ibm/ibmvnic.c | 137 ++++++++++++++++++++----------------- 1 file changed, 74 insertions(+), 63 deletions(-) (limited to 'drivers/net/ethernet/ibm') diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index 4603597a9c10..dafb36690fdc 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -108,6 +108,8 @@ static int init_crq_queue(struct ibmvnic_adapter *adapter); static int send_query_phys_parms(struct ibmvnic_adapter *adapter); static void ibmvnic_tx_scrq_clean_buffer(struct ibmvnic_adapter *adapter, struct ibmvnic_sub_crq_queue *tx_scrq); +static void free_long_term_buff(struct ibmvnic_adapter *adapter, + struct ibmvnic_long_term_buff *ltb); struct ibmvnic_stat { char name[ETH_GSTRING_LEN]; @@ -214,23 +216,77 @@ static int ibmvnic_wait_for_completion(struct ibmvnic_adapter *adapter, return -ETIMEDOUT; } +/** + * reuse_ltb() - Check if a long term buffer can be reused + * @ltb: The long term buffer to be checked + * @size: The size of the long term buffer. + * + * An LTB can be reused unless its size has changed. + * + * Return: Return true if the LTB can be reused, false otherwise. + */ +static bool reuse_ltb(struct ibmvnic_long_term_buff *ltb, int size) +{ + return (ltb->buff && ltb->size == size); +} + +/** + * alloc_long_term_buff() - Allocate a long term buffer (LTB) + * + * @adapter: ibmvnic adapter associated to the LTB + * @ltb: container object for the LTB + * @size: size of the LTB + * + * Allocate an LTB of the specified size and notify VIOS. + * + * If the given @ltb already has the correct size, reuse it. Otherwise if + * its non-NULL, free it. Then allocate a new one of the correct size. + * Notify the VIOS either way since we may now be working with a new VIOS. + * + * Allocating larger chunks of memory during resets, specially LPM or under + * low memory situations can cause resets to fail/timeout and for LPAR to + * lose connectivity. So hold onto the LTB even if we fail to communicate + * with the VIOS and reuse it on next open. Free LTB when adapter is closed. + * + * Return: 0 if we were able to allocate the LTB and notify the VIOS and + * a negative value otherwise. + */ static int alloc_long_term_buff(struct ibmvnic_adapter *adapter, struct ibmvnic_long_term_buff *ltb, int size) { struct device *dev = &adapter->vdev->dev; int rc; - ltb->size = size; - ltb->buff = dma_alloc_coherent(dev, ltb->size, <b->addr, - GFP_KERNEL); + if (!reuse_ltb(ltb, size)) { + dev_dbg(dev, + "LTB size changed from 0x%llx to 0x%x, reallocating\n", + ltb->size, size); + free_long_term_buff(adapter, ltb); + } - if (!ltb->buff) { - dev_err(dev, "Couldn't alloc long term buffer\n"); - return -ENOMEM; + if (ltb->buff) { + dev_dbg(dev, "Reusing LTB [map %d, size 0x%llx]\n", + ltb->map_id, ltb->size); + } else { + ltb->buff = dma_alloc_coherent(dev, size, <b->addr, + GFP_KERNEL); + if (!ltb->buff) { + dev_err(dev, "Couldn't alloc long term buffer\n"); + return -ENOMEM; + } + ltb->size = size; + + ltb->map_id = find_first_zero_bit(adapter->map_ids, + MAX_MAP_ID); + bitmap_set(adapter->map_ids, ltb->map_id, 1); + + dev_dbg(dev, + "Allocated new LTB [map %d, size 0x%llx]\n", + ltb->map_id, ltb->size); } - ltb->map_id = find_first_zero_bit(adapter->map_ids, - MAX_MAP_ID); - bitmap_set(adapter->map_ids, ltb->map_id, 1); + + /* Ensure ltb is zeroed - specially when reusing it. */ + memset(ltb->buff, 0, ltb->size); mutex_lock(&adapter->fw_lock); adapter->fw_done_rc = 0; @@ -257,10 +313,7 @@ static int alloc_long_term_buff(struct ibmvnic_adapter *adapter, } rc = 0; out: - if (rc) { - dma_free_coherent(dev, ltb->size, ltb->buff, ltb->addr); - ltb->buff = NULL; - } + /* don't free LTB on communication error - see function header */ mutex_unlock(&adapter->fw_lock); return rc; } @@ -290,43 +343,6 @@ static void free_long_term_buff(struct ibmvnic_adapter *adapter, ltb->map_id = 0; } -static int reset_long_term_buff(struct ibmvnic_adapter *adapter, - struct ibmvnic_long_term_buff *ltb) -{ - struct device *dev = &adapter->vdev->dev; - int rc; - - memset(ltb->buff, 0, ltb->size); - - mutex_lock(&adapter->fw_lock); - adapter->fw_done_rc = 0; - - reinit_completion(&adapter->fw_done); - rc = send_request_map(adapter, ltb->addr, ltb->size, ltb->map_id); - if (rc) { - mutex_unlock(&adapter->fw_lock); - return rc; - } - - rc = ibmvnic_wait_for_completion(adapter, &adapter->fw_done, 10000); - if (rc) { - dev_info(dev, - "Reset failed, long term map request timed out or aborted\n"); - mutex_unlock(&adapter->fw_lock); - return rc; - } - - if (adapter->fw_done_rc) { - dev_info(dev, - "Reset failed, attempting to free and reallocate buffer\n"); - free_long_term_buff(adapter, ltb); - mutex_unlock(&adapter->fw_lock); - return alloc_long_term_buff(adapter, ltb, ltb->size); - } - mutex_unlock(&adapter->fw_lock); - return 0; -} - static void deactivate_rx_pools(struct ibmvnic_adapter *adapter) { int i; @@ -548,18 +564,10 @@ static int reset_rx_pools(struct ibmvnic_adapter *adapter) netdev_dbg(adapter->netdev, "Re-setting rx_pool[%d]\n", i); - if (rx_pool->buff_size != buff_size) { - free_long_term_buff(adapter, &rx_pool->long_term_buff); - rx_pool->buff_size = ALIGN(buff_size, L1_CACHE_BYTES); - rc = alloc_long_term_buff(adapter, - &rx_pool->long_term_buff, - rx_pool->size * - rx_pool->buff_size); - } else { - rc = reset_long_term_buff(adapter, - &rx_pool->long_term_buff); - } - + rx_pool->buff_size = ALIGN(buff_size, L1_CACHE_BYTES); + rc = alloc_long_term_buff(adapter, + &rx_pool->long_term_buff, + rx_pool->size * rx_pool->buff_size); if (rc) return rc; @@ -694,9 +702,12 @@ static int init_rx_pools(struct net_device *netdev) static int reset_one_tx_pool(struct ibmvnic_adapter *adapter, struct ibmvnic_tx_pool *tx_pool) { + struct ibmvnic_long_term_buff *ltb; int rc, i; - rc = reset_long_term_buff(adapter, &tx_pool->long_term_buff); + ltb = &tx_pool->long_term_buff; + + rc = alloc_long_term_buff(adapter, ltb, ltb->size); if (rc) return rc; -- cgit v1.2.3-59-g8ed1b