Commit f8ac0bfa authored by Sukadev Bhattiprolu's avatar Sukadev Bhattiprolu Committed by David S. Miller
Browse files

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: default avatarRick Lindsley <ricklind@linux.vnet.ibm.com>
Reviewed-by: default avatarDany Madden <drt@linux.ibm.com>
Signed-off-by: default avatarSukadev Bhattiprolu <sukadev@linux.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 129854f0

drivers/net/ethernet/ibm/ibmvnic.c

+74 −63
Original line number Diff line number Diff line
@@ -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];
@@ -214,24 +216,78 @@ 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, &ltb->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_dbg(dev, "Reusing LTB [map %d, size 0x%llx]\n",

			ltb->map_id, ltb->size);

	} else {

		ltb->buff = dma_alloc_coherent(dev, size, &ltb->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);

	}



	/* Ensure ltb is zeroed - specially when reusing it. */

	memset(ltb->buff, 0, ltb->size);



	mutex_lock(&adapter->fw_lock);

	adapter->fw_done_rc = 0;

	reinit_completion(&adapter->fw_done);
@@ -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->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;