Commit 48a6c7bc authored by Nipun Gupta's avatar Nipun Gupta Committed by Greg Kroah-Hartman
Browse files

cdx: add device attributes 



Create sysfs entry for CDX devices.

Sysfs entries provided in each of the CDX device detected by
the CDX controller
 - vendor id
 - device id
 - remove
 - reset of the device.
 - driver override

Signed-off-by: default avatarPuneet Gupta <puneet.gupta@amd.com>
Signed-off-by: default avatarNipun Gupta <nipun.gupta@amd.com>
Signed-off-by: default avatarTarak Reddy <tarak.reddy@amd.com>
Reviewed-by: default avatarPieter Jansen van Vuuren <pieter.jansen-van-vuuren@amd.com>
Tested-by: default avatarNikhil Agarwal <nikhil.agarwal@amd.com>
Link: https://lore.kernel.org/r/20230313132636.31850-8-nipun.gupta@amd.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 2a226927

Documentation/ABI/testing/sysfs-bus-cdx

+44 −0
Original line number Diff line number Diff line
@@ -10,3 +10,47 @@ Description: 
		For example::



		  # echo 1 > /sys/bus/cdx/rescan



What:		/sys/bus/cdx/devices/.../vendor

Date:		March 2023

Contact:	nipun.gupta@amd.com

Description:

		Vendor ID for this CDX device, in hexadecimal. Vendor ID is

		16 bit identifier which is specific to the device manufacturer.

		Combination of Vendor ID and Device ID identifies a device.



What:		/sys/bus/cdx/devices/.../device

Date:		March 2023

Contact:	nipun.gupta@amd.com

Description:

		Device ID for this CDX device, in hexadecimal. Device ID is

		16 bit identifier to identify a device type within the range

		of a device manufacturer.

		Combination of Vendor ID and Device ID identifies a device.



What:		/sys/bus/cdx/devices/.../reset

Date:		March 2023

Contact:	nipun.gupta@amd.com

Description:

		Writing y/1/on to this file resets the CDX device.

		On resetting the device, the corresponding driver is notified

		twice, once before the device is being reset, and again after

		the reset has been complete.



		For example::



		  # echo 1 > /sys/bus/cdx/.../reset



What:		/sys/bus/cdx/devices/.../remove

Date:		March 2023

Contact:	tarak.reddy@amd.com

Description:

		Writing y/1/on to this file removes the corresponding

		device from the CDX bus. If the device is to be reconfigured

		reconfigured in the Hardware, the device can be removed, so

		that the device driver does not access the device while it is

		being reconfigured.



		For example::



		  # echo 1 > /sys/bus/cdx/devices/.../remove

drivers/cdx/cdx.c

+127 −0
Original line number Diff line number Diff line
@@ -71,6 +71,39 @@ 
/* CDX controllers registered with the CDX bus */

static DEFINE_XARRAY_ALLOC(cdx_controllers);



/**

 * cdx_dev_reset - Reset a CDX device

 * @dev: CDX device

 *

 * Return: -errno on failure, 0 on success.

 */

int cdx_dev_reset(struct device *dev)

{

	struct cdx_device *cdx_dev = to_cdx_device(dev);

	struct cdx_controller *cdx = cdx_dev->cdx;

	struct cdx_device_config dev_config = {0};

	struct cdx_driver *cdx_drv;

	int ret;



	cdx_drv = to_cdx_driver(dev->driver);

	/* Notify driver that device is being reset */

	if (cdx_drv && cdx_drv->reset_prepare)

		cdx_drv->reset_prepare(cdx_dev);



	dev_config.type = CDX_DEV_RESET_CONF;

	ret = cdx->ops->dev_configure(cdx, cdx_dev->bus_num,

				      cdx_dev->dev_num, &dev_config);

	if (ret)

		dev_err(dev, "cdx device reset failed\n");



	/* Notify driver that device reset is complete */

	if (cdx_drv && cdx_drv->reset_done)

		cdx_drv->reset_done(cdx_dev);



	return ret;

}

EXPORT_SYMBOL_GPL(cdx_dev_reset);



/**

 * cdx_unregister_device - Unregister a CDX device

 * @dev: CDX device
@@ -237,6 +270,99 @@ static int cdx_dma_configure(struct device *dev) 
	return 0;

}



/* show configuration fields */

#define cdx_config_attr(field, format_string)	\

static ssize_t	\

field##_show(struct device *dev, struct device_attribute *attr, char *buf)	\

{	\

	struct cdx_device *cdx_dev = to_cdx_device(dev);	\

	return sysfs_emit(buf, format_string, cdx_dev->field);	\

}	\

static DEVICE_ATTR_RO(field)



cdx_config_attr(vendor, "0x%04x\n");

cdx_config_attr(device, "0x%04x\n");



static ssize_t remove_store(struct device *dev,

			    struct device_attribute *attr,

			    const char *buf, size_t count)

{

	bool val;



	if (kstrtobool(buf, &val) < 0)

		return -EINVAL;



	if (!val)

		return -EINVAL;



	if (device_remove_file_self(dev, attr)) {

		int ret;



		ret = cdx_unregister_device(dev, NULL);

		if (ret)

			return ret;

	}



	return count;

}

static DEVICE_ATTR_WO(remove);



static ssize_t reset_store(struct device *dev, struct device_attribute *attr,

			   const char *buf, size_t count)

{

	bool val;

	int ret;



	if (kstrtobool(buf, &val) < 0)

		return -EINVAL;



	if (!val)

		return -EINVAL;



	ret = cdx_dev_reset(dev);

	if (ret)

		return ret;



	return count;

}

static DEVICE_ATTR_WO(reset);



static ssize_t driver_override_store(struct device *dev,

				     struct device_attribute *attr,

				     const char *buf, size_t count)

{

	struct cdx_device *cdx_dev = to_cdx_device(dev);

	int ret;



	if (WARN_ON(dev->bus != &cdx_bus_type))

		return -EINVAL;



	ret = driver_set_override(dev, &cdx_dev->driver_override, buf, count);

	if (ret)

		return ret;



	return count;

}



static ssize_t driver_override_show(struct device *dev,

				    struct device_attribute *attr, char *buf)

{

	struct cdx_device *cdx_dev = to_cdx_device(dev);



	return sysfs_emit(buf, "%s\n", cdx_dev->driver_override);

}

static DEVICE_ATTR_RW(driver_override);



static struct attribute *cdx_dev_attrs[] = {

	&dev_attr_remove.attr,

	&dev_attr_reset.attr,

	&dev_attr_vendor.attr,

	&dev_attr_device.attr,

	&dev_attr_driver_override.attr,

	NULL,

};

ATTRIBUTE_GROUPS(cdx_dev);



static ssize_t rescan_store(struct bus_type *bus,

			    const char *buf, size_t count)

{
@@ -280,6 +406,7 @@ struct bus_type cdx_bus_type = { 
	.shutdown	= cdx_shutdown,

	.dma_configure	= cdx_dma_configure,

	.bus_groups	= cdx_bus_groups,

	.dev_groups	= cdx_dev_groups,

};

EXPORT_SYMBOL_GPL(cdx_bus_type);

drivers/cdx/controller/cdx_controller.c

+18 −0
Original line number Diff line number Diff line
@@ -45,6 +45,23 @@ void cdx_rpmsg_pre_remove(struct cdx_controller *cdx) 
	cdx_mcdi_wait_for_quiescence(cdx->priv, MCDI_RPC_TIMEOUT);

}



static int cdx_configure_device(struct cdx_controller *cdx,

				u8 bus_num, u8 dev_num,

				struct cdx_device_config *dev_config)

{

	int ret = 0;



	switch (dev_config->type) {

	case CDX_DEV_RESET_CONF:

		ret = cdx_mcdi_reset_device(cdx->priv, bus_num, dev_num);

		break;

	default:

		ret = -EINVAL;

	}



	return ret;

}



static int cdx_scan_devices(struct cdx_controller *cdx)

{

	struct cdx_mcdi *cdx_mcdi = cdx->priv;
@@ -104,6 +121,7 @@ static int cdx_scan_devices(struct cdx_controller *cdx) 


static struct cdx_ops cdx_ops = {

	.scan		= cdx_scan_devices,

	.dev_configure	= cdx_configure_device,

};



static int xlnx_cdx_probe(struct platform_device *pdev)

drivers/cdx/controller/mcdi_functions.c

+14 −0
Original line number Diff line number Diff line
@@ -123,3 +123,17 @@ int cdx_mcdi_get_dev_config(struct cdx_mcdi *cdx, 


	return 0;

}



int cdx_mcdi_reset_device(struct cdx_mcdi *cdx, u8 bus_num, u8 dev_num)

{

	MCDI_DECLARE_BUF(inbuf, MC_CMD_CDX_DEVICE_RESET_IN_LEN);

	int ret;



	MCDI_SET_DWORD(inbuf, CDX_DEVICE_RESET_IN_BUS, bus_num);

	MCDI_SET_DWORD(inbuf, CDX_DEVICE_RESET_IN_DEVICE, dev_num);



	ret = cdx_mcdi_rpc(cdx, MC_CMD_CDX_DEVICE_RESET, inbuf, sizeof(inbuf),

			   NULL, 0, NULL);



	return ret;

}

drivers/cdx/controller/mcdi_functions.h

+11 −0
Original line number Diff line number Diff line
@@ -47,4 +47,15 @@ int cdx_mcdi_get_dev_config(struct cdx_mcdi *cdx, 
			    u8 bus_num, u8 dev_num,

			    struct cdx_dev_params *dev_params);



/**

 * cdx_mcdi_reset_device - Reset cdx device represented by bus_num:dev_num

 * @cdx: pointer to MCDI interface.

 * @bus_num: Bus number.

 * @dev_num: Device number.

 *

 * Return: 0 on success, <0 on failure

 */

int cdx_mcdi_reset_device(struct cdx_mcdi *cdx,

			  u8 bus_num, u8 dev_num);



#endif /* CDX_MCDI_FUNCTIONS_H */