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Message-Id: <20230817212239.2601543-16-anthony.l.nguyen@intel.com>
Date: Thu, 17 Aug 2023 14:22:39 -0700
From: Tony Nguyen <anthony.l.nguyen@...el.com>
To: davem@...emloft.net,
kuba@...nel.org,
pabeni@...hat.com,
edumazet@...gle.com,
netdev@...r.kernel.org
Cc: Przemek Kitszel <przemyslaw.kitszel@...el.com>,
anthony.l.nguyen@...el.com,
Jacob Keller <jacob.e.keller@...el.com>,
Simon Horman <horms@...nel.org>,
Pucha Himasekhar Reddy <himasekharx.reddy.pucha@...el.com>,
Leon Romanovsky <leonro@...dia.com>
Subject: [PATCH net-next v2 15/15] ice: split ice_aq_wait_for_event() func into two
From: Przemek Kitszel <przemyslaw.kitszel@...el.com>
Mitigate race between registering on wait list and receiving
AQ Response from FW.
ice_aq_prep_for_event() should be called before sending AQ command,
ice_aq_wait_for_event() should be called after sending AQ command,
to wait for AQ Response.
Please note, that this was found by reading the code,
an actual race has not yet materialized.
Reviewed-by: Jacob Keller <jacob.e.keller@...el.com>
Signed-off-by: Przemek Kitszel <przemyslaw.kitszel@...el.com>
Reviewed-by: Simon Horman <horms@...nel.org>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@...el.com> (A Contingent worker at Intel)
Reviewed-by: Leon Romanovsky <leonro@...dia.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@...el.com>
---
drivers/net/ethernet/intel/ice/ice.h | 5 +-
.../net/ethernet/intel/ice/ice_fw_update.c | 13 ++--
drivers/net/ethernet/intel/ice/ice_main.c | 67 ++++++++++++-------
3 files changed, 57 insertions(+), 28 deletions(-)
diff --git a/drivers/net/ethernet/intel/ice/ice.h b/drivers/net/ethernet/intel/ice/ice.h
index 9a334287bd92..5022b036ca4f 100644
--- a/drivers/net/ethernet/intel/ice/ice.h
+++ b/drivers/net/ethernet/intel/ice/ice.h
@@ -919,6 +919,7 @@ void ice_fdir_replay_fltrs(struct ice_pf *pf);
int ice_fdir_create_dflt_rules(struct ice_pf *pf);
enum ice_aq_task_state {
+ ICE_AQ_TASK_NOT_PREPARED,
ICE_AQ_TASK_WAITING,
ICE_AQ_TASK_COMPLETE,
ICE_AQ_TASK_CANCELED,
@@ -931,8 +932,10 @@ struct ice_aq_task {
u16 opcode;
};
+void ice_aq_prep_for_event(struct ice_pf *pf, struct ice_aq_task *task,
+ u16 opcode);
int ice_aq_wait_for_event(struct ice_pf *pf, struct ice_aq_task *task,
- u16 opcode, unsigned long timeout);
+ unsigned long timeout);
int ice_open(struct net_device *netdev);
int ice_open_internal(struct net_device *netdev);
int ice_stop(struct net_device *netdev);
diff --git a/drivers/net/ethernet/intel/ice/ice_fw_update.c b/drivers/net/ethernet/intel/ice/ice_fw_update.c
index 819b70823e9c..319a2d6fe26c 100644
--- a/drivers/net/ethernet/intel/ice/ice_fw_update.c
+++ b/drivers/net/ethernet/intel/ice/ice_fw_update.c
@@ -302,6 +302,8 @@ ice_write_one_nvm_block(struct ice_pf *pf, u16 module, u32 offset,
dev_dbg(dev, "Writing block of %u bytes for module 0x%02x at offset %u\n",
block_size, module, offset);
+ ice_aq_prep_for_event(pf, &task, ice_aqc_opc_nvm_write);
+
err = ice_aq_update_nvm(hw, module, offset, block_size, block,
last_cmd, 0, NULL);
if (err) {
@@ -318,7 +320,7 @@ ice_write_one_nvm_block(struct ice_pf *pf, u16 module, u32 offset,
* is conservative and is intended to prevent failure to update when
* firmware is slow to respond.
*/
- err = ice_aq_wait_for_event(pf, &task, ice_aqc_opc_nvm_write, 15 * HZ);
+ err = ice_aq_wait_for_event(pf, &task, 15 * HZ);
if (err) {
dev_err(dev, "Timed out while trying to flash module 0x%02x with block of size %u at offset %u, err %d\n",
module, block_size, offset, err);
@@ -491,6 +493,8 @@ ice_erase_nvm_module(struct ice_pf *pf, u16 module, const char *component,
devlink_flash_update_timeout_notify(devlink, "Erasing", component, ICE_FW_ERASE_TIMEOUT);
+ ice_aq_prep_for_event(pf, &task, ice_aqc_opc_nvm_erase);
+
err = ice_aq_erase_nvm(hw, module, NULL);
if (err) {
dev_err(dev, "Failed to erase %s (module 0x%02x), err %d aq_err %s\n",
@@ -501,7 +505,7 @@ ice_erase_nvm_module(struct ice_pf *pf, u16 module, const char *component,
goto out_notify_devlink;
}
- err = ice_aq_wait_for_event(pf, &task, ice_aqc_opc_nvm_erase, ICE_FW_ERASE_TIMEOUT * HZ);
+ err = ice_aq_wait_for_event(pf, &task, ICE_FW_ERASE_TIMEOUT * HZ);
if (err) {
dev_err(dev, "Timed out waiting for firmware to respond with erase completion for %s (module 0x%02x), err %d\n",
component, module, err);
@@ -566,6 +570,8 @@ ice_switch_flash_banks(struct ice_pf *pf, u8 activate_flags,
u8 response_flags;
int err;
+ ice_aq_prep_for_event(pf, &task, ice_aqc_opc_nvm_write_activate);
+
err = ice_nvm_write_activate(hw, activate_flags, &response_flags);
if (err) {
dev_err(dev, "Failed to switch active flash banks, err %d aq_err %s\n",
@@ -590,8 +596,7 @@ ice_switch_flash_banks(struct ice_pf *pf, u8 activate_flags,
}
}
- err = ice_aq_wait_for_event(pf, &task, ice_aqc_opc_nvm_write_activate,
- 30 * HZ);
+ err = ice_aq_wait_for_event(pf, &task, 30 * HZ);
if (err) {
dev_err(dev, "Timed out waiting for firmware to switch active flash banks, err %d\n",
err);
diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index b08be6700b2a..81c1018b57d1 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -1251,30 +1251,24 @@ ice_handle_link_event(struct ice_pf *pf, struct ice_rq_event_info *event)
}
/**
- * ice_aq_wait_for_event - Wait for an AdminQ event from firmware
+ * ice_aq_prep_for_event - Prepare to wait for an AdminQ event from firmware
* @pf: pointer to the PF private structure
- * @task: ptr to task structure
+ * @task: intermediate helper storage and identifier for waiting
* @opcode: the opcode to wait for
- * @timeout: how long to wait, in jiffies
*
- * Waits for a specific AdminQ completion event on the ARQ for a given PF. The
- * current thread will be put to sleep until the specified event occurs or
- * until the given timeout is reached.
+ * Prepares to wait for a specific AdminQ completion event on the ARQ for
+ * a given PF. Actual wait would be done by a call to ice_aq_wait_for_event().
*
- * To obtain only the descriptor contents, pass an event without an allocated
- * msg_buf. If the complete data buffer is desired, allocate the
- * event->msg_buf with enough space ahead of time.
+ * Calls are separated to allow caller registering for event before sending
+ * the command, which mitigates a race between registering and FW responding.
*
- * Returns: zero on success, or a negative error code on failure.
+ * To obtain only the descriptor contents, pass an task->event with null
+ * msg_buf. If the complete data buffer is desired, allocate the
+ * task->event.msg_buf with enough space ahead of time.
*/
-int ice_aq_wait_for_event(struct ice_pf *pf, struct ice_aq_task *task,
- u16 opcode, unsigned long timeout)
+void ice_aq_prep_for_event(struct ice_pf *pf, struct ice_aq_task *task,
+ u16 opcode)
{
- struct device *dev = ice_pf_to_dev(pf);
- unsigned long start;
- long ret;
- int err;
-
INIT_HLIST_NODE(&task->entry);
task->opcode = opcode;
task->state = ICE_AQ_TASK_WAITING;
@@ -1282,12 +1276,37 @@ int ice_aq_wait_for_event(struct ice_pf *pf, struct ice_aq_task *task,
spin_lock_bh(&pf->aq_wait_lock);
hlist_add_head(&task->entry, &pf->aq_wait_list);
spin_unlock_bh(&pf->aq_wait_lock);
+}
- start = jiffies;
+/**
+ * ice_aq_wait_for_event - Wait for an AdminQ event from firmware
+ * @pf: pointer to the PF private structure
+ * @task: ptr prepared by ice_aq_prep_for_event()
+ * @timeout: how long to wait, in jiffies
+ *
+ * Waits for a specific AdminQ completion event on the ARQ for a given PF. The
+ * current thread will be put to sleep until the specified event occurs or
+ * until the given timeout is reached.
+ *
+ * Returns: zero on success, or a negative error code on failure.
+ */
+int ice_aq_wait_for_event(struct ice_pf *pf, struct ice_aq_task *task,
+ unsigned long timeout)
+{
+ enum ice_aq_task_state *state = &task->state;
+ struct device *dev = ice_pf_to_dev(pf);
+ unsigned long start = jiffies;
+ long ret;
+ int err;
- ret = wait_event_interruptible_timeout(pf->aq_wait_queue, task->state,
+ ret = wait_event_interruptible_timeout(pf->aq_wait_queue,
+ *state != ICE_AQ_TASK_WAITING,
timeout);
- switch (task->state) {
+ switch (*state) {
+ case ICE_AQ_TASK_NOT_PREPARED:
+ WARN(1, "call to %s without ice_aq_prep_for_event()", __func__);
+ err = -EINVAL;
+ break;
case ICE_AQ_TASK_WAITING:
err = ret < 0 ? ret : -ETIMEDOUT;
break;
@@ -1298,7 +1317,7 @@ int ice_aq_wait_for_event(struct ice_pf *pf, struct ice_aq_task *task,
err = ret < 0 ? ret : 0;
break;
default:
- WARN(1, "Unexpected AdminQ wait task state %u", task->state);
+ WARN(1, "Unexpected AdminQ wait task state %u", *state);
err = -EINVAL;
break;
}
@@ -1306,7 +1325,7 @@ int ice_aq_wait_for_event(struct ice_pf *pf, struct ice_aq_task *task,
dev_dbg(dev, "Waited %u msecs (max %u msecs) for firmware response to op 0x%04x\n",
jiffies_to_msecs(jiffies - start),
jiffies_to_msecs(timeout),
- opcode);
+ task->opcode);
spin_lock_bh(&pf->aq_wait_lock);
hlist_del(&task->entry);
@@ -1342,7 +1361,9 @@ static void ice_aq_check_events(struct ice_pf *pf, u16 opcode,
spin_lock_bh(&pf->aq_wait_lock);
hlist_for_each_entry(task, &pf->aq_wait_list, entry) {
- if (task->state || task->opcode != opcode)
+ if (task->state != ICE_AQ_TASK_WAITING)
+ continue;
+ if (task->opcode != opcode)
continue;
task_ev = &task->event;
--
2.38.1
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