Commit 7964f8fc authored by Vadim Pasternak's avatar Vadim Pasternak Committed by Hans de Goede
Browse files

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



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

Signed-off-by: default avatarVadim Pasternak <vadimp@nvidia.com>
Link: https://lore.kernel.org/r/20220711084559.62447-8-vadimp@nvidia.com


Reviewed-by: default avatarHans de Goede <hdegoede@redhat.com>
Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
parent 095a2c18

drivers/platform/mellanox/mlxreg-io.c

+23 −0
Original line number Diff line number Diff line
@@ -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);