ice: split ice_aq_wait_for_event() func into two

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@intel.com>
Signed-off-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
This commit is contained in:
Przemek Kitszel 2023-08-08 17:54:17 -04:00 committed by Tony Nguyen
parent b214b98a7f
commit fb9840c4ec
3 changed files with 57 additions and 28 deletions

View file

@ -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);

View file

@ -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);

View file

@ -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
* Calls are separated to allow caller registering for event before sending
* the command, which mitigates a race between registering and FW responding.
*
* To obtain only the descriptor contents, pass an task->event with null
* msg_buf. If the complete data buffer is desired, allocate the
* event->msg_buf with enough space ahead of time.
*
* Returns: zero on success, or a negative error code on failure.
* 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;