pds_core: add new fwctl auxiliary_device

Add support for a new fwctl-based auxiliary_device for creating a
channel for fwctl support into the AMD/Pensando DSC.

Link: https://patch.msgid.link/r/20250320194412.67983-4-shannon.nelson@amd.com
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

Author: emusln

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

@@ -224,8 +224,8 @@ int pdsc_auxbus_dev_add(struct pdsc *cf, struct pdsc *pf,
 	}
 
 	/* Verify that the type is supported and enabled.  It is not
-	 * an error if there is no auxbus device support for this
-	 * VF, it just means something else needs to happen with it.
+	 * an error if the firmware doesn't support the feature, the
+	 * driver just won't set up an auxiliary_device for it.
 	 */
 	vt_support = !!le16_to_cpu(pf->dev_ident.vif_types[vt]);
 	if (!(vt_support &&

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

@@ -402,6 +402,9 @@ static int pdsc_core_init(struct pdsc *pdsc)
 }
 
 static struct pdsc_viftype pdsc_viftype_defaults[] = {
+	[PDS_DEV_TYPE_FWCTL] = { .name = PDS_DEV_TYPE_FWCTL_STR,
+				 .vif_id = PDS_DEV_TYPE_FWCTL,
+				 .dl_id = -1 },
 	[PDS_DEV_TYPE_VDPA] = { .name = PDS_DEV_TYPE_VDPA_STR,
 				.vif_id = PDS_DEV_TYPE_VDPA,
 				.dl_id = DEVLINK_PARAM_GENERIC_ID_ENABLE_VNET },
@@ -428,6 +431,10 @@ static int pdsc_viftypes_init(struct pdsc *pdsc)
 
 		/* See what the Core device has for support */
 		vt_support = !!le16_to_cpu(pdsc->dev_ident.vif_types[vt]);
+
+		if (vt == PDS_DEV_TYPE_FWCTL)
+			pdsc->viftype_status[vt].enabled = true;
+
 		dev_dbg(pdsc->dev, "VIF %s is %ssupported\n",
 			pdsc->viftype_status[vt].name,
 			vt_support ? "" : "not ");

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

@@ -156,6 +156,7 @@ struct pdsc {
 	struct dentry *dentry;
 	struct device *dev;
 	struct pdsc_dev_bar bars[PDS_CORE_BARS_MAX];
+	struct pds_auxiliary_dev *padev;
 	struct pdsc_vf *vfs;
 	int num_vfs;
 	int vf_id;

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

@@ -265,6 +265,10 @@ static int pdsc_init_pf(struct pdsc *pdsc)
 
 	mutex_unlock(&pdsc->config_lock);
 
+	err = pdsc_auxbus_dev_add(pdsc, pdsc, PDS_DEV_TYPE_FWCTL, &pdsc->padev);
+	if (err)
+		goto err_out_stop;
+
 	dl = priv_to_devlink(pdsc);
 	devl_lock(dl);
 	err = devl_params_register(dl, pdsc_dl_params,
@@ -273,7 +277,7 @@ static int pdsc_init_pf(struct pdsc *pdsc)
 		devl_unlock(dl);
 		dev_warn(pdsc->dev, "Failed to register devlink params: %pe\n",
 			 ERR_PTR(err));
-		goto err_out_stop;
+		goto err_out_del_dev;
 	}
 
 	hr = devl_health_reporter_create(dl, &pdsc_fw_reporter_ops, 0, pdsc);
@@ -296,6 +300,8 @@ static int pdsc_init_pf(struct pdsc *pdsc)
 err_out_unreg_params:
 	devlink_params_unregister(dl, pdsc_dl_params,
 				  ARRAY_SIZE(pdsc_dl_params));
+err_out_del_dev:
+	pdsc_auxbus_dev_del(pdsc, pdsc, &pdsc->padev);
 err_out_stop:
 	pdsc_stop(pdsc);
 err_out_teardown:
@@ -427,6 +433,7 @@ static void pdsc_remove(struct pci_dev *pdev)
 		 * shut themselves down.
 		 */
 		pdsc_sriov_configure(pdev, 0);
+		pdsc_auxbus_dev_del(pdsc, pdsc, &pdsc->padev);
 
 		timer_shutdown_sync(&pdsc->wdtimer);
 		if (pdsc->wq)
@@ -485,6 +492,8 @@ static void pdsc_reset_prepare(struct pci_dev *pdev)
 		if (!IS_ERR(pf))
 			pdsc_auxbus_dev_del(pdsc, pf,
 					    &pf->vfs[pdsc->vf_id].padev);
+	} else {
+		pdsc_auxbus_dev_del(pdsc, pdsc, &pdsc->padev);
 	}
 
 	pdsc_unmap_bars(pdsc);
@@ -531,6 +540,9 @@ static void pdsc_reset_done(struct pci_dev *pdev)
 		if (!IS_ERR(pf))
 			pdsc_auxbus_dev_add(pdsc, pf, PDS_DEV_TYPE_VDPA,
 					    &pf->vfs[pdsc->vf_id].padev);
+	} else {
+		pdsc_auxbus_dev_add(pdsc, pdsc, PDS_DEV_TYPE_FWCTL,
+				    &pdsc->padev);
 	}
 }
 

include/linux/pds/pds_common.h

@@ -29,6 +29,7 @@ enum pds_core_vif_types {
 	PDS_DEV_TYPE_ETH	= 3,
 	PDS_DEV_TYPE_RDMA	= 4,
 	PDS_DEV_TYPE_LM		= 5,
+	PDS_DEV_TYPE_FWCTL	= 6,
 
 	/* new ones added before this line */
 	PDS_DEV_TYPE_MAX	= 16   /* don't change - used in struct size */
@@ -40,6 +41,7 @@ enum pds_core_vif_types {
 #define PDS_DEV_TYPE_ETH_STR	"Eth"
 #define PDS_DEV_TYPE_RDMA_STR	"RDMA"
 #define PDS_DEV_TYPE_LM_STR	"LM"
+#define PDS_DEV_TYPE_FWCTL_STR	"fwctl"
 
 #define PDS_VDPA_DEV_NAME	PDS_CORE_DRV_NAME "." PDS_DEV_TYPE_VDPA_STR
 #define PDS_VFIO_LM_DEV_NAME	PDS_CORE_DRV_NAME "." PDS_DEV_TYPE_LM_STR "." PDS_DEV_TYPE_VFIO_STR