crypto: qat - expose device config through sysfs for 4xxx

qat_4xxx devices can be configured to allow either crypto or compression
operations. At the moment, devices are configured statically according to
the following rule:
- odd numbered devices assigned to compression services
- even numbered devices assigned to crypto services

Expose the sysfs attribute /sys/bus/pci/devices/<BDF>/qat/cfg_services
to allow to detect the configuration of a device and to change it.

The `cfg_service` attribute is only exposed for qat_4xxx devices and it
is limited to two configurations: (1) "sym;asym" for crypto services and
"dc" for compression services.
Signed-off-by: NGiovanni Cabiddu <giovanni.cabiddu@intel.com>
Co-developed-by: NTomasz Kowallik <tomaszx.kowalik@intel.com>
Signed-off-by: NTomasz Kowallik <tomaszx.kowalik@intel.com>
Reviewed-by: NAdam Guerin <adam.guerin@intel.com>
Reviewed-by: NFiona Trahe <fiona.trahe@intel.com>
Reviewed-by: NWojciech Ziemba <wojciech.ziemba@intel.com>
Reviewed-by: NVladis Dronov <vdronov@redhat.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Documentation/ABI/testing/sysfs-driver-qat

@@ -19,3 +19,42 @@ Description:	Reports the current state of the QAT device and allows to
 		if the device is up and vice versa.
 
 		This attribute is only available for qat_4xxx devices.
+
+What:		/sys/bus/pci/devices/<BDF>/qat/cfg_services
+Date:		June 2022
+KernelVersion:	5.20
+Contact:	qat-linux@intel.com
+Description:	Reports the current configuration of the QAT device and allows
+		to change it.
+
+		This attribute is RW.
+
+		Returned values:
+			sym;asym:	the device is configured for running
+					crypto services
+			dc:		the device is configured for running
+					compression services
+
+		Allowed values:
+			sym;asym:	configure the device for running
+					crypto services
+			dc:		configure the device for running
+					compression services
+
+		It is possible to set the configuration only if the device
+		is in the `down` state (see /sys/bus/pci/devices/<BDF>/qat/state)
+
+		The following example shows how to change the configuration of
+		a device configured for running crypto services in order to
+		run data compression:
+			# cat /sys/bus/pci/devices/<BDF>/qat/state
+			up
+			# cat /sys/bus/pci/devices/<BDF>/qat/cfg_services
+			sym;asym
+			# echo down > /sys/bus/pci/devices/<BDF>/qat/state
+			# echo dc > /sys/bus/pci/devices/<BDF>/qat/cfg_services
+			# echo up > /sys/bus/pci/devices/<BDF>/qat/state
+			# cat /sys/bus/pci/devices/<BDF>/qat/cfg_services
+			dc
+
+		This attribute is only available for qat_4xxx devices.

drivers/crypto/qat/qat_common/adf_sysfs.c

@@ -58,8 +58,9 @@ static ssize_t state_store(struct device *dev, struct device_attribute *attr,
 
 		dev_info(dev, "Stopping device qat_dev%d\n", accel_id);
 
-		adf_dev_stop(accel_dev);
-		adf_dev_shutdown(accel_dev);
+		ret = adf_dev_shutdown_cache_cfg(accel_dev);
+		if (ret < 0)
+			return -EINVAL;
 
 		break;
 	case DEV_UP:
@@ -80,8 +81,7 @@ static ssize_t state_store(struct device *dev, struct device_attribute *attr,
 		if (ret < 0) {
 			dev_err(dev, "Failed to start device qat_dev%d\n",
 				accel_id);
-			adf_dev_stop(accel_dev);
-			adf_dev_shutdown(accel_dev);
+			adf_dev_shutdown_cache_cfg(accel_dev);
 			return ret;
 		}
 		break;
@@ -92,10 +92,82 @@ static ssize_t state_store(struct device *dev, struct device_attribute *attr,
 	return count;
 }
 
+static const char * const services_operations[] = {
+	ADF_CFG_CY,
+	ADF_CFG_DC,
+};
+
+static ssize_t cfg_services_show(struct device *dev, struct device_attribute *attr,
+				 char *buf)
+{
+	char services[ADF_CFG_MAX_VAL_LEN_IN_BYTES] = {0};
+	struct adf_accel_dev *accel_dev;
+	int ret;
+
+	accel_dev = adf_devmgr_pci_to_accel_dev(to_pci_dev(dev));
+	if (!accel_dev)
+		return -EINVAL;
+
+	ret = adf_cfg_get_param_value(accel_dev, ADF_GENERAL_SEC,
+				      ADF_SERVICES_ENABLED, services);
+	if (ret)
+		return ret;
+
+	return sysfs_emit(buf, "%s\n", services);
+}
+
+static int adf_sysfs_update_dev_config(struct adf_accel_dev *accel_dev,
+				       const char *services)
+{
+	return adf_cfg_add_key_value_param(accel_dev, ADF_GENERAL_SEC,
+					   ADF_SERVICES_ENABLED, services,
+					   ADF_STR);
+}
+
+static ssize_t cfg_services_store(struct device *dev, struct device_attribute *attr,
+				  const char *buf, size_t count)
+{
+	struct adf_hw_device_data *hw_data;
+	struct adf_accel_dev *accel_dev;
+	int ret;
+
+	ret = sysfs_match_string(services_operations, buf);
+	if (ret < 0)
+		return ret;
+
+	accel_dev = adf_devmgr_pci_to_accel_dev(to_pci_dev(dev));
+	if (!accel_dev)
+		return -EINVAL;
+
+	if (adf_dev_started(accel_dev)) {
+		dev_info(dev, "Device qat_dev%d must be down to reconfigure the service.\n",
+			 accel_dev->accel_id);
+		return -EINVAL;
+	}
+
+	ret = adf_sysfs_update_dev_config(accel_dev, services_operations[ret]);
+	if (ret < 0)
+		return ret;
+
+	hw_data = GET_HW_DATA(accel_dev);
+
+	/* Update capabilities mask after change in configuration.
+	 * A call to this function is required as capabilities are, at the
+	 * moment, tied to configuration
+	 */
+	hw_data->accel_capabilities_mask = hw_data->get_accel_cap(accel_dev);
+	if (!hw_data->accel_capabilities_mask)
+		return -EINVAL;
+
+	return count;
+}
+
 static DEVICE_ATTR_RW(state);
+static DEVICE_ATTR_RW(cfg_services);
 
 static struct attribute *qat_attrs[] = {
 	&dev_attr_state.attr,
+	&dev_attr_cfg_services.attr,
 	NULL,
 };