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Date: Tue, 14 Sep 2021 20:52:57 -0700
From: Sukadev Bhattiprolu <sukadev@...ux.ibm.com>
To: netdev@...r.kernel.org
Cc: Brian King <brking@...ux.ibm.com>, cforno12@...ux.ibm.com,
Dany Madden <drt@...ux.ibm.com>,
Rick Lindsley <ricklind@...ux.ibm.com>,
Rick Lindsley <ricklind@...ux.vnet.ibm.com>
Subject: [PATCH net-next RESEND v2 7/9] 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 <ricklind@...ux.vnet.ibm.com>
Reviewed-by: Dany Madden <drt@...ux.ibm.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@...ux.ibm.com>
---
Changelog[v2]: [Jakub Kicinski] Fix kdoc issues
---
drivers/net/ethernet/ibm/ibmvnic.c | 137 ++++++++++++++++-------------
1 file changed, 74 insertions(+), 63 deletions(-)
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;
--
2.26.2
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