pds_core: devlink params for enabling VIF support

Add the devlink parameter switches so the user can enable
the features supported by the VFs. The only feature supported
at the moment is vDPA.

Example:
devlink dev param set pci/0000:2b:00.0 \
name enable_vnet cmode runtime value true

Signed-off-by: Shannon Nelson <[e-mail]>
Acked-by: Jakub Kicinski <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

Documentation/networking/device_drivers/ethernet/amd/pds_core.rst

···
      - fixed
      - The revision of the ASIC for this device
 
+Parameters
+==========
+
+The ``pds_core`` driver implements the following generic
+parameters for controlling the functionality to be made available
+as auxiliary_bus devices.
+
+.. list-table:: Generic parameters implemented
+   :widths: 5 5 8 82
+
+   * - Name
+     - Mode
+     - Type
+     - Description
+   * - ``enable_vnet``
+     - runtime
+     - Boolean
+     - Enables vDPA functionality through an auxiliary_bus device
+
 Firmware Management
 ===================
 

drivers/net/ethernet/amd/pds_core/core.h

···
 int pdsc_dl_flash_update(struct devlink *dl,
 			 struct devlink_flash_update_params *params,
 			 struct netlink_ext_ack *extack);
+int pdsc_dl_enable_get(struct devlink *dl, u32 id,
+		       struct devlink_param_gset_ctx *ctx);
+int pdsc_dl_enable_set(struct devlink *dl, u32 id,
+		       struct devlink_param_gset_ctx *ctx);
+int pdsc_dl_enable_validate(struct devlink *dl, u32 id,
+			    union devlink_param_value val,
+			    struct netlink_ext_ack *extack);
 
 void __iomem *pdsc_map_dbpage(struct pdsc *pdsc, int page_num);
 

drivers/net/ethernet/amd/pds_core/devlink.c

···
 /* Copyright(c) 2023 Advanced Micro Devices, Inc */
 
 #include "core.h"
+#include <linux/pds/pds_auxbus.h>
+
+static struct
+pdsc_viftype *pdsc_dl_find_viftype_by_id(struct pdsc *pdsc,
+					 enum devlink_param_type dl_id)
+{
+	int vt;
+
+	for (vt = 0; vt < PDS_DEV_TYPE_MAX; vt++) {
+		if (pdsc->viftype_status[vt].dl_id == dl_id)
+			return &pdsc->viftype_status[vt];
+	}
+
+	return NULL;
+}
+
+int pdsc_dl_enable_get(struct devlink *dl, u32 id,
+		       struct devlink_param_gset_ctx *ctx)
+{
+	struct pdsc *pdsc = devlink_priv(dl);
+	struct pdsc_viftype *vt_entry;
+
+	vt_entry = pdsc_dl_find_viftype_by_id(pdsc, id);
+	if (!vt_entry)
+		return -ENOENT;
+
+	ctx->val.vbool = vt_entry->enabled;
+
+	return 0;
+}
+
+int pdsc_dl_enable_set(struct devlink *dl, u32 id,
+		       struct devlink_param_gset_ctx *ctx)
+{
+	struct pdsc *pdsc = devlink_priv(dl);
+	struct pdsc_viftype *vt_entry;
+	int err = 0;
+	int vf_id;
+
+	vt_entry = pdsc_dl_find_viftype_by_id(pdsc, id);
+	if (!vt_entry || !vt_entry->supported)
+		return -EOPNOTSUPP;
+
+	if (vt_entry->enabled == ctx->val.vbool)
+		return 0;
+
+	vt_entry->enabled = ctx->val.vbool;
+	for (vf_id = 0; vf_id < pdsc->num_vfs; vf_id++) {
+		struct pdsc *vf = pdsc->vfs[vf_id].vf;
+
+		err = ctx->val.vbool ? pdsc_auxbus_dev_add(vf, pdsc) :
+				       pdsc_auxbus_dev_del(vf, pdsc);
+	}
+
+	return err;
+}
+
+int pdsc_dl_enable_validate(struct devlink *dl, u32 id,
+			    union devlink_param_value val,
+			    struct netlink_ext_ack *extack)
+{
+	struct pdsc *pdsc = devlink_priv(dl);
+	struct pdsc_viftype *vt_entry;
+
+	vt_entry = pdsc_dl_find_viftype_by_id(pdsc, id);
+	if (!vt_entry || !vt_entry->supported)
+		return -EOPNOTSUPP;
+
+	if (!pdsc->viftype_status[vt_entry->vif_id].supported)
+		return -ENODEV;
+
+	return 0;
+}
 
 int pdsc_dl_flash_update(struct devlink *dl,
 			 struct devlink_flash_update_params *params,

drivers/net/ethernet/amd/pds_core/main.c

···
 	.diagnose = pdsc_fw_reporter_diagnose,
 };
 
+static const struct devlink_param pdsc_dl_params[] = {
+	DEVLINK_PARAM_GENERIC(ENABLE_VNET,
+			      BIT(DEVLINK_PARAM_CMODE_RUNTIME),
+			      pdsc_dl_enable_get,
+			      pdsc_dl_enable_set,
+			      pdsc_dl_enable_validate),
+};
+
 #define PDSC_WQ_NAME_LEN 24
 
 static int pdsc_init_pf(struct pdsc *pdsc)
···
 
 	dl = priv_to_devlink(pdsc);
 	devl_lock(dl);
+	err = devl_params_register(dl, pdsc_dl_params,
+				   ARRAY_SIZE(pdsc_dl_params));
+	if (err) {
+		dev_warn(pdsc->dev, "Failed to register devlink params: %pe\n",
+			 ERR_PTR(err));
+		goto err_out_unlock_dl;
+	}
 
 	hr = devl_health_reporter_create(dl, &pdsc_fw_reporter_ops, 0, pdsc);
 	if (IS_ERR(hr)) {
 		dev_warn(pdsc->dev, "Failed to create fw reporter: %pe\n", hr);
 		err = PTR_ERR(hr);
-		devl_unlock(dl);
-		goto err_out_stop;
+		goto err_out_unreg_params;
 	}
 	pdsc->fw_reporter = hr;
 
···
 
 	return 0;
 
-err_out_stop:
+err_out_unreg_params:
+	devl_params_unregister(dl, pdsc_dl_params,
+			       ARRAY_SIZE(pdsc_dl_params));
+err_out_unlock_dl:
+	devl_unlock(dl);
 	pdsc_stop(pdsc);
 err_out_teardown:
 	pdsc_teardown(pdsc, PDSC_TEARDOWN_REMOVING);
···
 	dl = priv_to_devlink(pdsc);
 	devl_lock(dl);
 	devl_unregister(dl);
-	if (pdsc->fw_reporter) {
-		devl_health_reporter_destroy(pdsc->fw_reporter);
-		pdsc->fw_reporter = NULL;
+	if (!pdev->is_virtfn) {
+		if (pdsc->fw_reporter) {
+			devl_health_reporter_destroy(pdsc->fw_reporter);
+			pdsc->fw_reporter = NULL;
+		}
+		devl_params_unregister(dl, pdsc_dl_params,
+				       ARRAY_SIZE(pdsc_dl_params));
 	}
 	devl_unlock(dl);