1 files changed, 264 insertions, 0 deletions
diff --git a/drivers/net/ethernet/amd/pds_core/auxbus.c b/drivers/net/ethernet/amd/pds_core/auxbus.c
new file mode 100644
index 000000000000..561af8e5b3ea
--- /dev/null
+++ b/drivers/net/ethernet/amd/pds_core/auxbus.c
@@ -0,0 +1,264 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2023 Advanced Micro Devices, Inc */
+
+#include <linux/pci.h>
+
+#include "core.h"
+#include <linux/pds/pds_auxbus.h>
+
+/**
+ * pds_client_register - Link the client to the firmware
+ * @pf_pdev:	ptr to the PF driver struct
+ * @devname:	name that includes service into, e.g. pds_core.vDPA
+ *
+ * Return: 0 on success, or
+ *         negative for error
+ */
+int pds_client_register(struct pci_dev *pf_pdev, char *devname)
+{
+	union pds_core_adminq_comp comp = {};
+	union pds_core_adminq_cmd cmd = {};
+	struct pdsc *pf;
+	int err;
+	u16 ci;
+
+	pf = pci_get_drvdata(pf_pdev);
+	if (pf->state)
+		return -ENXIO;
+
+	cmd.client_reg.opcode = PDS_AQ_CMD_CLIENT_REG;
+	strscpy(cmd.client_reg.devname, devname,
+		sizeof(cmd.client_reg.devname));
+
+	err = pdsc_adminq_post(pf, &cmd, &comp, false);
+	if (err) {
+		dev_info(pf->dev, "register dev_name %s with DSC failed, status %d: %pe\n",
+			 devname, comp.status, ERR_PTR(err));
+		return err;
+	}
+
+	ci = le16_to_cpu(comp.client_reg.client_id);
+	if (!ci) {
+		dev_err(pf->dev, "%s: device returned null client_id\n",
+			__func__);
+		return -EIO;
+	}
+
+	dev_dbg(pf->dev, "%s: device returned client_id %d for %s\n",
+		__func__, ci, devname);
+
+	return ci;
+}
+EXPORT_SYMBOL_GPL(pds_client_register);
+
+/**
+ * pds_client_unregister - Unlink the client from the firmware
+ * @pf_pdev:	ptr to the PF driver struct
+ * @client_id:	id returned from pds_client_register()
+ *
+ * Return: 0 on success, or
+ *         negative for error
+ */
+int pds_client_unregister(struct pci_dev *pf_pdev, u16 client_id)
+{
+	union pds_core_adminq_comp comp = {};
+	union pds_core_adminq_cmd cmd = {};
+	struct pdsc *pf;
+	int err;
+
+	pf = pci_get_drvdata(pf_pdev);
+	if (pf->state)
+		return -ENXIO;
+
+	cmd.client_unreg.opcode = PDS_AQ_CMD_CLIENT_UNREG;
+	cmd.client_unreg.client_id = cpu_to_le16(client_id);
+
+	err = pdsc_adminq_post(pf, &cmd, &comp, false);
+	if (err)
+		dev_info(pf->dev, "unregister client_id %d failed, status %d: %pe\n",
+			 client_id, comp.status, ERR_PTR(err));
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(pds_client_unregister);
+
+/**
+ * pds_client_adminq_cmd - Process an adminq request for the client
+ * @padev:   ptr to the client device
+ * @req:     ptr to buffer with request
+ * @req_len: length of actual struct used for request
+ * @resp:    ptr to buffer where answer is to be copied
+ * @flags:   optional flags from pds_core_adminq_flags
+ *
+ * Return: 0 on success, or
+ *         negative for error
+ *
+ * Client sends pointers to request and response buffers
+ * Core copies request data into pds_core_client_request_cmd
+ * Core sets other fields as needed
+ * Core posts to AdminQ
+ * Core copies completion data into response buffer
+ */
+int pds_client_adminq_cmd(struct pds_auxiliary_dev *padev,
+			  union pds_core_adminq_cmd *req,
+			  size_t req_len,
+			  union pds_core_adminq_comp *resp,
+			  u64 flags)
+{
+	union pds_core_adminq_cmd cmd = {};
+	struct pci_dev *pf_pdev;
+	struct pdsc *pf;
+	size_t cp_len;
+	int err;
+
+	pf_pdev = pci_physfn(padev->vf_pdev);
+	pf = pci_get_drvdata(pf_pdev);
+
+	dev_dbg(pf->dev, "%s: %s opcode %d\n",
+		__func__, dev_name(&padev->aux_dev.dev), req->opcode);
+
+	if (pf->state)
+		return -ENXIO;
+
+	/* Wrap the client's request */
+	cmd.client_request.opcode = PDS_AQ_CMD_CLIENT_CMD;
+	cmd.client_request.client_id = cpu_to_le16(padev->client_id);
+	cp_len = min_t(size_t, req_len, sizeof(cmd.client_request.client_cmd));
+	memcpy(cmd.client_request.client_cmd, req, cp_len);
+
+	err = pdsc_adminq_post(pf, &cmd, resp,
+			       !!(flags & PDS_AQ_FLAG_FASTPOLL));
+	if (err && err != -EAGAIN)
+		dev_info(pf->dev, "client admin cmd failed: %pe\n",
+			 ERR_PTR(err));
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(pds_client_adminq_cmd);
+
+static void pdsc_auxbus_dev_release(struct device *dev)
+{
+	struct pds_auxiliary_dev *padev =
+		container_of(dev, struct pds_auxiliary_dev, aux_dev.dev);
+
+	kfree(padev);
+}
+
+static struct pds_auxiliary_dev *pdsc_auxbus_dev_register(struct pdsc *cf,
+							  struct pdsc *pf,
+							  u16 client_id,
+							  char *name)
+{
+	struct auxiliary_device *aux_dev;
+	struct pds_auxiliary_dev *padev;
+	int err;
+
+	padev = kzalloc(sizeof(*padev), GFP_KERNEL);
+	if (!padev)
+		return ERR_PTR(-ENOMEM);
+
+	padev->vf_pdev = cf->pdev;
+	padev->client_id = client_id;
+
+	aux_dev = &padev->aux_dev;
+	aux_dev->name = name;
+	aux_dev->id = cf->uid;
+	aux_dev->dev.parent = cf->dev;
+	aux_dev->dev.release = pdsc_auxbus_dev_release;
+
+	err = auxiliary_device_init(aux_dev);
+	if (err < 0) {
+		dev_warn(cf->dev, "auxiliary_device_init of %s failed: %pe\n",
+			 name, ERR_PTR(err));
+		goto err_out;
+	}
+
+	err = auxiliary_device_add(aux_dev);
+	if (err) {
+		dev_warn(cf->dev, "auxiliary_device_add of %s failed: %pe\n",
+			 name, ERR_PTR(err));
+		goto err_out_uninit;
+	}
+
+	return padev;
+
+err_out_uninit:
+	auxiliary_device_uninit(aux_dev);
+err_out:
+	kfree(padev);
+	return ERR_PTR(err);
+}
+
+int pdsc_auxbus_dev_del(struct pdsc *cf, struct pdsc *pf)
+{
+	struct pds_auxiliary_dev *padev;
+	int err = 0;
+
+	mutex_lock(&pf->config_lock);
+
+	padev = pf->vfs[cf->vf_id].padev;
+	if (padev) {
+		pds_client_unregister(pf->pdev, padev->client_id);
+		auxiliary_device_delete(&padev->aux_dev);
+		auxiliary_device_uninit(&padev->aux_dev);
+		padev->client_id = 0;
+	}
+	pf->vfs[cf->vf_id].padev = NULL;
+
+	mutex_unlock(&pf->config_lock);
+	return err;
+}
+
+int pdsc_auxbus_dev_add(struct pdsc *cf, struct pdsc *pf)
+{
+	struct pds_auxiliary_dev *padev;
+	enum pds_core_vif_types vt;
+	char devname[PDS_DEVNAME_LEN];
+	u16 vt_support;
+	int client_id;
+	int err = 0;
+
+	mutex_lock(&pf->config_lock);
+
+	/* We only support vDPA so far, so it is the only one to
+	 * be verified that it is available in the Core device and
+	 * enabled in the devlink param.  In the future this might
+	 * become a loop for several VIF types.
+	 */
+
+	/* 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.
+	 */
+	vt = PDS_DEV_TYPE_VDPA;
+	vt_support = !!le16_to_cpu(pf->dev_ident.vif_types[vt]);
+	if (!(vt_support &&
+	      pf->viftype_status[vt].supported &&
+	      pf->viftype_status[vt].enabled))
+		goto out_unlock;
+
+	/* Need to register with FW and get the client_id before
+	 * creating the aux device so that the aux client can run
+	 * adminq commands as part its probe
+	 */
+	snprintf(devname, sizeof(devname), "%s.%s.%d",
+		 PDS_CORE_DRV_NAME, pf->viftype_status[vt].name, cf->uid);
+	client_id = pds_client_register(pf->pdev, devname);
+	if (client_id < 0) {
+		err = client_id;
+		goto out_unlock;
+	}
+
+	padev = pdsc_auxbus_dev_register(cf, pf, client_id,
+					 pf->viftype_status[vt].name);
+	if (IS_ERR(padev)) {
+		pds_client_unregister(pf->pdev, client_id);
+		err = PTR_ERR(padev);
+		goto out_unlock;
+	}
+	pf->vfs[cf->vf_id].padev = padev;
+
+out_unlock:
+	mutex_unlock(&pf->config_lock);
+	return err;
+}