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platform/mellanox: mlxreg-io: Add locking for io operations

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Add lock to protect user read/write access to the registers.

Signed-off-by: Vadim Pasternak <vadimp@nvidia.com>
Link: https://lore.kernel.org/r/20220711084559.62447-8-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 2022-07-11 11:45:57 +03:00 committed by Hans de Goede
parent 095a2c1891
commit 7964f8fc52
1 changed files with 23 additions and 0 deletions
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23
drivers/platform/mellanox/mlxreg-io.c
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@ -31,6 +31,7 @@
* @group: sysfs attribute group;
* @groups: list of sysfs attribute group for hwmon registration;
* @regsize: size of a register value;
* @io_lock: user access locking;
*/
struct mlxreg_io_priv_data {
struct platform_device *pdev;
@ -41,6 +42,7 @@ struct mlxreg_io_priv_data {
struct attribute_group group;
const struct attribute_group *groups[2];
int regsize;
struct mutex io_lock; /* Protects user access. */
};
static int
@ -116,14 +118,19 @@ mlxreg_io_attr_show(struct device *dev, struct device_attribute *attr,
u32 regval = 0;
int ret;
mutex_lock(&priv->io_lock);
ret = mlxreg_io_get_reg(priv->pdata->regmap, data, 0, true,
priv->regsize, &regval);
if (ret)
goto access_error;
mutex_unlock(&priv->io_lock);
return sprintf(buf, "%u\n", regval);
access_error:
mutex_unlock(&priv->io_lock);
return ret;
}
@ -145,6 +152,8 @@ mlxreg_io_attr_store(struct device *dev, struct device_attribute *attr,
if (ret)
return ret;
mutex_lock(&priv->io_lock);
ret = mlxreg_io_get_reg(priv->pdata->regmap, data, input_val, false,
priv->regsize, &regval);
if (ret)
@ -154,9 +163,12 @@ mlxreg_io_attr_store(struct device *dev, struct device_attribute *attr,
if (ret)
goto access_error;
mutex_unlock(&priv->io_lock);
return len;
access_error:
mutex_unlock(&priv->io_lock);
dev_err(&priv->pdev->dev, "Bus access error\n");
return ret;
}
@ -246,16 +258,27 @@ static int mlxreg_io_probe(struct platform_device *pdev)
return PTR_ERR(priv->hwmon);
}
mutex_init(&priv->io_lock);
dev_set_drvdata(&pdev->dev, priv);
return 0;
}
static int mlxreg_io_remove(struct platform_device *pdev)
{
struct mlxreg_io_priv_data *priv = dev_get_drvdata(&pdev->dev);
mutex_destroy(&priv->io_lock);
return 0;
}
static struct platform_driver mlxreg_io_driver = {
.driver = {
.name = "mlxreg-io",
},
.probe = mlxreg_io_probe,
.remove = mlxreg_io_remove,
};
module_platform_driver(mlxreg_io_driver);