Re: [PATCH net 4/4] ibmvnic: Serialize device queries

[Jakub Kicinski]

On Fri, 22 Nov 2019 13:41:46 -0600, Thomas Falcon wrote:
> @@ -5050,6 +5090,7 @@ static int ibmvnic_probe(struct vio_dev *dev, const 
> struct vio_device_id *id)
> __ibmvnic_delayed_reset);
>   INIT_LIST_HEAD(>rwi_list);
>   spin_lock_init(>rwi_lock);
> + mutex_init(>fw_lock);
>   init_completion(>init_done);
>   init_completion(>fw_done);
>   init_completion(>reset_done);

Could you also add a mutex_destroy() call?

[PATCH net 4/4] ibmvnic: Serialize device queries

[Thomas Falcon]

Provide some serialization for device CRQ commands
and queries to ensure that the shared variable used for
storing return codes is properly synchronized.

Signed-off-by: Thomas Falcon 
---
 drivers/net/ethernet/ibm/ibmvnic.c | 51 ++
 drivers/net/ethernet/ibm/ibmvnic.h |  1 +
 2 files changed, 47 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c 
b/drivers/net/ethernet/ibm/ibmvnic.c
index 9806eccc5670..5e9b7711cd2e 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -207,11 +207,14 @@ static int alloc_long_term_buff(struct ibmvnic_adapter 
*adapter,
ltb->map_id = adapter->map_id;
adapter->map_id++;
 
+   mutex_lock(>fw_lock);
+   adapter->fw_done_rc = 0;
reinit_completion(>fw_done);
rc = send_request_map(adapter, ltb->addr,
  ltb->size, ltb->map_id);
if (rc) {
dma_free_coherent(dev, ltb->size, ltb->buff, ltb->addr);
+   mutex_unlock(>fw_lock);
return rc;
}
 
@@ -222,6 +225,7 @@ static int alloc_long_term_buff(struct ibmvnic_adapter 
*adapter,
"Long term map request aborted or timed out,rc = %d\n",
rc);
dma_free_coherent(dev, ltb->size, ltb->buff, ltb->addr);
+   mutex_unlock(>fw_lock);
return rc;
}
 
@@ -229,8 +233,10 @@ static int alloc_long_term_buff(struct ibmvnic_adapter 
*adapter,
dev_err(dev, "Couldn't map long term buffer,rc = %d\n",
adapter->fw_done_rc);
dma_free_coherent(dev, ltb->size, ltb->buff, ltb->addr);
+   mutex_unlock(>fw_lock);
return -1;
}
+   mutex_unlock(>fw_lock);
return 0;
 }
 
@@ -256,16 +262,21 @@ static int reset_long_term_buff(struct ibmvnic_adapter 
*adapter,
 
memset(ltb->buff, 0, ltb->size);
 
+   mutex_lock(>fw_lock);
+   adapter->fw_done_rc = 0;
reinit_completion(>fw_done);
rc = send_request_map(adapter, ltb->addr, ltb->size, ltb->map_id);
-   if (rc)
+   if (rc) {
+   mutex_unlock(>fw_lock);
return rc;
+   }
 
rc = ibmvnic_wait_for_completion(adapter, >fw_done,
 msecs_to_jiffies(1));
if (rc) {
dev_info(dev,
 "Reset failed, long term map request timed out or 
aborted\n");
+   mutex_unlock(>fw_lock);
return rc;
}
 
@@ -273,8 +284,10 @@ static int reset_long_term_buff(struct ibmvnic_adapter 
*adapter,
dev_info(dev,
 "Reset failed, attempting to free and reallocate 
buffer\n");
free_long_term_buff(adapter, ltb);
+   mutex_unlock(>fw_lock);
return alloc_long_term_buff(adapter, ltb, ltb->size);
}
+   mutex_unlock(>fw_lock);
return 0;
 }
 
@@ -991,19 +1004,26 @@ static int ibmvnic_get_vpd(struct ibmvnic_adapter 
*adapter)
if (adapter->vpd->buff)
len = adapter->vpd->len;
 
+   mutex_lock(>fw_lock);
+   adapter->fw_done_rc = 0;
reinit_completion(>fw_done);
+
crq.get_vpd_size.first = IBMVNIC_CRQ_CMD;
crq.get_vpd_size.cmd = GET_VPD_SIZE;
rc = ibmvnic_send_crq(adapter, );
-   if (rc)
+   if (rc) {
+   mutex_unlock(>fw_lock);
return rc;
+   }
 
rc = ibmvnic_wait_for_completion(adapter, >fw_done,
 msecs_to_jiffies(1));
if (rc) {
dev_err(dev, "Could not retrieve VPD size, rc = %d\n", rc);
+   mutex_unlock(>fw_lock);
return rc;
}
+   mutex_unlock(>fw_lock);
 
if (!adapter->vpd->len)
return -ENODATA;
@@ -1030,7 +1050,10 @@ static int ibmvnic_get_vpd(struct ibmvnic_adapter 
*adapter)
return -ENOMEM;
}
 
+   mutex_lock(>fw_lock);
+   adapter->fw_done_rc = 0;
reinit_completion(>fw_done);
+
crq.get_vpd.first = IBMVNIC_CRQ_CMD;
crq.get_vpd.cmd = GET_VPD;
crq.get_vpd.ioba = cpu_to_be32(adapter->vpd->dma_addr);
@@ -1039,6 +1062,7 @@ static int ibmvnic_get_vpd(struct ibmvnic_adapter 
*adapter)
if (rc) {
kfree(adapter->vpd->buff);
adapter->vpd->buff = NULL;
+   mutex_unlock(>fw_lock);
return rc;
}
 
@@ -1048,9 +1072,11 @@ static int ibmvnic_get_vpd(struct ibmvnic_adapter 
*adapter)
dev_err(dev, "Unable to retrieve VPD, rc = %d\n", rc);
kfree(adapter->vpd->buff);
adapter->vpd->buff = NULL;
+   mutex_unlock(>fw_lock);
return rc;
}
 
+   mutex_unlock(>fw_lock);
return 0;
 }
 
@@ -1751,10 +1777,14