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platform/mellanox: mlxreg-lc: Fix locking issue

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Fix locking issues:
- mlxreg_lc_state_update() takes a lock when set or clear
  "MLXREG_LC_POWERED".
- All the devices can be deleted before MLXREG_LC_POWERED flag is cleared.

To fix it:
- Add lock() / unlock() at the beginning / end of
  mlxreg_lc_event_handler() and remove locking from
  mlxreg_lc_power_on_off() and mlxreg_lc_enable_disable()
- Add locked version of mlxreg_lc_state_update() -
  mlxreg_lc_state_update_locked() for using outside
  mlxreg_lc_event_handler().

(2) Remove redundant NULL check for of if 'data->notifier'.

Fixes: 62f9529b8d ("platform/mellanox: mlxreg-lc: Add initial support for Nvidia line card devices")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Vadim Pasternak <vadimp@nvidia.com>
Link: https://lore.kernel.org/r/20220823201937.46855-3-vadimp@nvidia.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
This commit is contained in:
Vadim Pasternak 2022-08-23 23:19:35 +03:00 committed by Hans de Goede
parent 16b36a953b
commit 52e01c0b1d
1 changed files with 25 additions and 12 deletions
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37
drivers/platform/mellanox/mlxreg-lc.c
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@ -460,8 +460,6 @@ static int mlxreg_lc_power_on_off(struct mlxreg_lc *mlxreg_lc, u8 action)
u32 regval;
int err;
mutex_lock(&mlxreg_lc->lock);
err = regmap_read(mlxreg_lc->par_regmap, mlxreg_lc->data->reg_pwr, &regval);
if (err)
goto regmap_read_fail;
@ -474,7 +472,6 @@ static int mlxreg_lc_power_on_off(struct mlxreg_lc *mlxreg_lc, u8 action)
err = regmap_write(mlxreg_lc->par_regmap, mlxreg_lc->data->reg_pwr, regval);
regmap_read_fail:
mutex_unlock(&mlxreg_lc->lock);
return err;
}
@ -491,8 +488,6 @@ static int mlxreg_lc_enable_disable(struct mlxreg_lc *mlxreg_lc, bool action)
* line card which is already has been enabled. Disabling does not affect the disabled line
* card.
*/
mutex_lock(&mlxreg_lc->lock);
err = regmap_read(mlxreg_lc->par_regmap, mlxreg_lc->data->reg_ena, &regval);
if (err)
goto regmap_read_fail;
@ -505,7 +500,6 @@ static int mlxreg_lc_enable_disable(struct mlxreg_lc *mlxreg_lc, bool action)
err = regmap_write(mlxreg_lc->par_regmap, mlxreg_lc->data->reg_ena, regval);
regmap_read_fail:
mutex_unlock(&mlxreg_lc->lock);
return err;
}
@ -537,6 +531,15 @@ mlxreg_lc_sn4800_c16_config_init(struct mlxreg_lc *mlxreg_lc, void *regmap,
static void
mlxreg_lc_state_update(struct mlxreg_lc *mlxreg_lc, enum mlxreg_lc_state state, u8 action)
{
if (action)
mlxreg_lc->state |= state;
else
mlxreg_lc->state &= ~state;
}
static void
mlxreg_lc_state_update_locked(struct mlxreg_lc *mlxreg_lc, enum mlxreg_lc_state state, u8 action)
{
mutex_lock(&mlxreg_lc->lock);
@ -560,8 +563,11 @@ static int mlxreg_lc_event_handler(void *handle, enum mlxreg_hotplug_kind kind,
dev_info(mlxreg_lc->dev, "linecard#%d state %d event kind %d action %d\n",
mlxreg_lc->data->slot, mlxreg_lc->state, kind, action);
if (!(mlxreg_lc->state & MLXREG_LC_INITIALIZED))
mutex_lock(&mlxreg_lc->lock);
if (!(mlxreg_lc->state & MLXREG_LC_INITIALIZED)) {
mutex_unlock(&mlxreg_lc->lock);
return 0;
}
switch (kind) {
case MLXREG_HOTPLUG_LC_SYNCED:
@ -574,7 +580,7 @@ static int mlxreg_lc_event_handler(void *handle, enum mlxreg_hotplug_kind kind,
if (!(mlxreg_lc->state & MLXREG_LC_POWERED) && action) {
err = mlxreg_lc_power_on_off(mlxreg_lc, 1);
if (err)
return err;
goto mlxreg_lc_power_on_off_fail;
}
/* In case line card is configured - enable it. */
if (mlxreg_lc->state & MLXREG_LC_CONFIGURED && action)
@ -588,12 +594,13 @@ static int mlxreg_lc_event_handler(void *handle, enum mlxreg_hotplug_kind kind,
/* In case line card is configured - enable it. */
if (mlxreg_lc->state & MLXREG_LC_CONFIGURED)
err = mlxreg_lc_enable_disable(mlxreg_lc, 1);
mutex_unlock(&mlxreg_lc->lock);
return err;
}
err = mlxreg_lc_create_static_devices(mlxreg_lc, mlxreg_lc->main_devs,
mlxreg_lc->main_devs_num);
if (err)
return err;
goto mlxreg_lc_create_static_devices_fail;
/* In case line card is already in ready state - enable it. */
if (mlxreg_lc->state & MLXREG_LC_CONFIGURED)
@ -620,6 +627,10 @@ static int mlxreg_lc_event_handler(void *handle, enum mlxreg_hotplug_kind kind,
break;
}
mlxreg_lc_power_on_off_fail:
mlxreg_lc_create_static_devices_fail:
mutex_unlock(&mlxreg_lc->lock);
return err;
}
@ -665,7 +676,7 @@ static int mlxreg_lc_completion_notify(void *handle, struct i2c_adapter *parent,
if (err)
goto mlxreg_lc_create_static_devices_failed;
mlxreg_lc_state_update(mlxreg_lc, MLXREG_LC_POWERED, 1);
mlxreg_lc_state_update_locked(mlxreg_lc, MLXREG_LC_POWERED, 1);
}
/* Verify if line card is synchronized. */
@ -676,7 +687,7 @@ static int mlxreg_lc_completion_notify(void *handle, struct i2c_adapter *parent,
/* Power on line card if necessary. */
if (regval & mlxreg_lc->data->mask) {
mlxreg_lc->state |= MLXREG_LC_SYNCED;
mlxreg_lc_state_update(mlxreg_lc, MLXREG_LC_SYNCED, 1);
mlxreg_lc_state_update_locked(mlxreg_lc, MLXREG_LC_SYNCED, 1);
if (mlxreg_lc->state & ~MLXREG_LC_POWERED) {
err = mlxreg_lc_power_on_off(mlxreg_lc, 1);
if (err)
@ -684,7 +695,7 @@ static int mlxreg_lc_completion_notify(void *handle, struct i2c_adapter *parent,
}
}
mlxreg_lc_state_update(mlxreg_lc, MLXREG_LC_INITIALIZED, 1);
mlxreg_lc_state_update_locked(mlxreg_lc, MLXREG_LC_INITIALIZED, 1);
return 0;
@ -904,6 +915,8 @@ static int mlxreg_lc_remove(struct platform_device *pdev)
struct mlxreg_core_data *data = dev_get_platdata(&pdev->dev);
struct mlxreg_lc *mlxreg_lc = platform_get_drvdata(pdev);
mlxreg_lc_state_update_locked(mlxreg_lc, MLXREG_LC_INITIALIZED, 0);
/*
* Probing and removing are invoked by hotplug events raised upon line card insertion and
* removing. If probing procedure fails all data is cleared. However, hotplug event still