6.10-stable review patch. If anyone has any objections, please let me know.
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From: Ziwei Xiao ziweixiao@google.com
[ Upstream commit 1108566ca509e67aa8abfbf914b1cd31e9ff51f8 ]
We were depending on the rtnl_lock to make sure there is only one adminq command running at a time. But some commands may take too long to hold the rtnl_lock, such as the upcoming flow steering operations. For such situations, it can temporarily drop the rtnl_lock, and replace it for these operations with a new adminq lock, which can ensure the adminq command execution to be thread-safe.
Signed-off-by: Ziwei Xiao ziweixiao@google.com Reviewed-by: Praveen Kaligineedi pkaligineedi@google.com Reviewed-by: Harshitha Ramamurthy hramamurthy@google.com Reviewed-by: Willem de Bruijn willemb@google.com Link: https://patch.msgid.link/20240625001232.1476315-2-ziweixiao@google.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/google/gve/gve.h | 1 + drivers/net/ethernet/google/gve/gve_adminq.c | 22 +++++++++++--------- 2 files changed, 13 insertions(+), 10 deletions(-)
diff --git a/drivers/net/ethernet/google/gve/gve.h b/drivers/net/ethernet/google/gve/gve.h index ae1e21c9b0a5..ca7fce17f2c0 100644 --- a/drivers/net/ethernet/google/gve/gve.h +++ b/drivers/net/ethernet/google/gve/gve.h @@ -724,6 +724,7 @@ struct gve_priv { union gve_adminq_command *adminq; dma_addr_t adminq_bus_addr; struct dma_pool *adminq_pool; + struct mutex adminq_lock; /* Protects adminq command execution */ u32 adminq_mask; /* masks prod_cnt to adminq size */ u32 adminq_prod_cnt; /* free-running count of AQ cmds executed */ u32 adminq_cmd_fail; /* free-running count of AQ cmds failed */ diff --git a/drivers/net/ethernet/google/gve/gve_adminq.c b/drivers/net/ethernet/google/gve/gve_adminq.c index 8ca0def176ef..2e0c1eb87b11 100644 --- a/drivers/net/ethernet/google/gve/gve_adminq.c +++ b/drivers/net/ethernet/google/gve/gve_adminq.c @@ -284,6 +284,7 @@ int gve_adminq_alloc(struct device *dev, struct gve_priv *priv) &priv->reg_bar0->adminq_base_address_lo); iowrite32be(GVE_DRIVER_STATUS_RUN_MASK, &priv->reg_bar0->driver_status); } + mutex_init(&priv->adminq_lock); gve_set_admin_queue_ok(priv); return 0; } @@ -511,28 +512,29 @@ static int gve_adminq_issue_cmd(struct gve_priv *priv, return 0; }
-/* This function is not threadsafe - the caller is responsible for any - * necessary locks. - * The caller is also responsible for making sure there are no commands - * waiting to be executed. - */ static int gve_adminq_execute_cmd(struct gve_priv *priv, union gve_adminq_command *cmd_orig) { u32 tail, head; int err;
+ mutex_lock(&priv->adminq_lock); tail = ioread32be(&priv->reg_bar0->adminq_event_counter); head = priv->adminq_prod_cnt; - if (tail != head) - // This is not a valid path - return -EINVAL; + if (tail != head) { + err = -EINVAL; + goto out; + }
err = gve_adminq_issue_cmd(priv, cmd_orig); if (err) - return err; + goto out;
- return gve_adminq_kick_and_wait(priv); + err = gve_adminq_kick_and_wait(priv); + +out: + mutex_unlock(&priv->adminq_lock); + return err; }
/* The device specifies that the management vector can either be the first irq