| Message ID | 20240209212432.750653-2-arkadiusz.kubalewski@intel.com |
|---|---|
| State | Accepted |
| Delegated to: | Anthony Nguyen |
| Headers | show |
| Series | ice: fix dpll data access on PF reset | expand |
> -----Original Message----- > From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of Arkadiusz Kubalewski > Sent: Saturday, February 10, 2024 2:55 AM > To: intel-wired-lan@lists.osuosl.org > Cc: Loktionov, Aleksandr <aleksandr.loktionov@intel.com>; Kitszel, Przemyslaw <przemyslaw.kitszel@intel.com>; Kubalewski, Arkadiusz <arkadiusz.kubalewski@intel.com> > Subject: [Intel-wired-lan] [PATCH iwl-net v2 1/3] ice: fix dpll and dpll_pin data access on PF reset > > Do not allow to acquire data or alter configuration of dpll and pins > through firmware if PF reset is in progress, this would cause confusing > netlink extack errors as the firmware cannot respond or process the > request properly during the reset time. > > Return (-EBUSY) and extack error for the user who tries access/modify > the config of dpll/pin through firmware during the reset time. > > The PF reset and kernel access to dpll data are both asynchronous. It is > not possible to guard all the possible reset paths with any determinictic > approach. I.e., it is possible that reset starts after reset check is > performed (or if the reset would be checked after mutex is locked), but at > the same time it is not possible to wait for dpll mutex unlock in the > reset flow. > This is best effort solution to at least give a clue to the user > what is happening in most of the cases, knowing that there are possible > race conditions where the user could see a different error received > from firmware due to reset unexpectedly starting. > > Test by looping execution of below steps until netlink error appears: > - perform PF reset > $ echo 1 > /sys/class/net/<ice PF>/device/reset > - i.e. try to alter/read dpll/pin config: > $ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/dpll.yaml \ > --dump pin-get > > Fixes: d7999f5ea64b ("ice: implement dpll interface to control cgu") > Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com> > Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com> > Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com> > --- > v2: > - remove newline from extack error > - change "pf" -> "PF" in extack error > --- > drivers/net/ethernet/intel/ice/ice_dpll.c | 38 +++++++++++++++++++++++ > 1 file changed, 38 insertions(+) > Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
diff --git a/drivers/net/ethernet/intel/ice/ice_dpll.c b/drivers/net/ethernet/intel/ice/ice_dpll.c index 9c0d739be1e9..58d135764ab0 100644 --- a/drivers/net/ethernet/intel/ice/ice_dpll.c +++ b/drivers/net/ethernet/intel/ice/ice_dpll.c @@ -30,6 +30,26 @@ static const char * const pin_type_name[] = { [ICE_DPLL_PIN_TYPE_RCLK_INPUT] = "rclk-input", }; +/** + * ice_dpll_is_reset - check if reset is in progress + * @pf: private board structure + * @extack: error reporting + * + * If reset is in progress, fill extack with error. + * + * Return: + * * false - no reset in progress + * * true - reset in progress + */ +static bool ice_dpll_is_reset(struct ice_pf *pf, struct netlink_ext_ack *extack) +{ + if (ice_is_reset_in_progress(pf->state)) { + NL_SET_ERR_MSG(extack, "PF reset in progress"); + return true; + } + return false; +} + /** * ice_dpll_pin_freq_set - set pin's frequency * @pf: private board structure @@ -109,6 +129,9 @@ ice_dpll_frequency_set(const struct dpll_pin *pin, void *pin_priv, struct ice_pf *pf = d->pf; int ret; + if (ice_dpll_is_reset(pf, extack)) + return -EBUSY; + mutex_lock(&pf->dplls.lock); ret = ice_dpll_pin_freq_set(pf, p, pin_type, frequency, extack); mutex_unlock(&pf->dplls.lock); @@ -584,6 +607,9 @@ ice_dpll_pin_state_set(const struct dpll_pin *pin, void *pin_priv, struct ice_pf *pf = d->pf; int ret; + if (ice_dpll_is_reset(pf, extack)) + return -EBUSY; + mutex_lock(&pf->dplls.lock); if (enable) ret = ice_dpll_pin_enable(&pf->hw, p, d->dpll_idx, pin_type, @@ -687,6 +713,9 @@ ice_dpll_pin_state_get(const struct dpll_pin *pin, void *pin_priv, struct ice_pf *pf = d->pf; int ret; + if (ice_dpll_is_reset(pf, extack)) + return -EBUSY; + mutex_lock(&pf->dplls.lock); ret = ice_dpll_pin_state_update(pf, p, pin_type, extack); if (ret) @@ -811,6 +840,9 @@ ice_dpll_input_prio_set(const struct dpll_pin *pin, void *pin_priv, struct ice_pf *pf = d->pf; int ret; + if (ice_dpll_is_reset(pf, extack)) + return -EBUSY; + mutex_lock(&pf->dplls.lock); ret = ice_dpll_hw_input_prio_set(pf, d, p, prio, extack); mutex_unlock(&pf->dplls.lock); @@ -1090,6 +1122,9 @@ ice_dpll_rclk_state_on_pin_set(const struct dpll_pin *pin, void *pin_priv, int ret = -EINVAL; u32 hw_idx; + if (ice_dpll_is_reset(pf, extack)) + return -EBUSY; + mutex_lock(&pf->dplls.lock); hw_idx = parent->idx - pf->dplls.base_rclk_idx; if (hw_idx >= pf->dplls.num_inputs) @@ -1144,6 +1179,9 @@ ice_dpll_rclk_state_on_pin_get(const struct dpll_pin *pin, void *pin_priv, int ret = -EINVAL; u32 hw_idx; + if (ice_dpll_is_reset(pf, extack)) + return -EBUSY; + mutex_lock(&pf->dplls.lock); hw_idx = parent->idx - pf->dplls.base_rclk_idx; if (hw_idx >= pf->dplls.num_inputs)
Do not allow to acquire data or alter configuration of dpll and pins through firmware if PF reset is in progress, this would cause confusing netlink extack errors as the firmware cannot respond or process the request properly during the reset time. Return (-EBUSY) and extack error for the user who tries access/modify the config of dpll/pin through firmware during the reset time. The PF reset and kernel access to dpll data are both asynchronous. It is not possible to guard all the possible reset paths with any determinictic approach. I.e., it is possible that reset starts after reset check is performed (or if the reset would be checked after mutex is locked), but at the same time it is not possible to wait for dpll mutex unlock in the reset flow. This is best effort solution to at least give a clue to the user what is happening in most of the cases, knowing that there are possible race conditions where the user could see a different error received from firmware due to reset unexpectedly starting. Test by looping execution of below steps until netlink error appears: - perform PF reset $ echo 1 > /sys/class/net/<ice PF>/device/reset - i.e. try to alter/read dpll/pin config: $ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/dpll.yaml \ --dump pin-get Fixes: d7999f5ea64b ("ice: implement dpll interface to control cgu") Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com> Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com> Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com> --- v2: - remove newline from extack error - change "pf" -> "PF" in extack error --- drivers/net/ethernet/intel/ice/ice_dpll.c | 38 +++++++++++++++++++++++ 1 file changed, 38 insertions(+)