[PATCH RFC v2 virtio 2/7] pds_vdpa: get vdpa management info

[Shannon Nelson <shannon.nelson@amd.com>]

Find the vDPA management information from the DSC in order to
advertise it to the vdpa subsystem.

Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
---
 drivers/vdpa/pds/Makefile    |   3 +-
 drivers/vdpa/pds/aux_drv.c   |  13 ++++
 drivers/vdpa/pds/aux_drv.h   |   7 +++
 drivers/vdpa/pds/debugfs.c   |   3 +
 drivers/vdpa/pds/vdpa_dev.c  | 113 +++++++++++++++++++++++++++++++++++
 drivers/vdpa/pds/vdpa_dev.h  |  15 +++++
 include/linux/pds/pds_vdpa.h |  92 ++++++++++++++++++++++++++++
 7 files changed, 245 insertions(+), 1 deletion(-)
 create mode 100644 drivers/vdpa/pds/vdpa_dev.c
 create mode 100644 drivers/vdpa/pds/vdpa_dev.h

diff --git a/drivers/vdpa/pds/Makefile b/drivers/vdpa/pds/Makefile
index a9cd2f450ae1..13b50394ec64 100644
--- a/drivers/vdpa/pds/Makefile
+++ b/drivers/vdpa/pds/Makefile
@@ -3,6 +3,7 @@
 
 obj-$(CONFIG_PDS_VDPA) := pds_vdpa.o
 
-pds_vdpa-y := aux_drv.o
+pds_vdpa-y := aux_drv.o \
+	      vdpa_dev.o
 
 pds_vdpa-$(CONFIG_DEBUG_FS) += debugfs.o
diff --git a/drivers/vdpa/pds/aux_drv.c b/drivers/vdpa/pds/aux_drv.c
index b3f36170253c..63e40ae68211 100644
--- a/drivers/vdpa/pds/aux_drv.c
+++ b/drivers/vdpa/pds/aux_drv.c
@@ -2,6 +2,8 @@
 /* Copyright(c) 2023 Advanced Micro Devices, Inc */
 
 #include <linux/auxiliary_bus.h>
+#include <linux/pci.h>
+#include <linux/vdpa.h>
 
 #include <linux/pds/pds_core.h>
 #include <linux/pds/pds_auxbus.h>
@@ -9,6 +11,7 @@
 
 #include "aux_drv.h"
 #include "debugfs.h"
+#include "vdpa_dev.h"
 
 static const struct auxiliary_device_id pds_vdpa_id_table[] = {
 	{ .name = PDS_VDPA_DEV_NAME, },
@@ -30,6 +33,7 @@ static int pds_vdpa_probe(struct auxiliary_device *aux_dev,
 		return -ENOMEM;
 
 	vdpa_aux->padev = padev;
+	vdpa_aux->vf_id = pci_iov_vf_id(padev->vf->pdev);
 	auxiliary_set_drvdata(aux_dev, vdpa_aux);
 
 	/* Register our PDS client with the pds_core */
@@ -40,8 +44,15 @@ static int pds_vdpa_probe(struct auxiliary_device *aux_dev,
 		goto err_free_mem;
 	}
 
+	/* Get device ident info and set up the vdpa_mgmt_dev */
+	err = pds_vdpa_get_mgmt_info(vdpa_aux);
+	if (err)
+		goto err_aux_unreg;
+
 	return 0;
 
+err_aux_unreg:
+	padev->ops->unregister_client(padev);
 err_free_mem:
 	kfree(vdpa_aux);
 	auxiliary_set_drvdata(aux_dev, NULL);
@@ -54,6 +65,8 @@ static void pds_vdpa_remove(struct auxiliary_device *aux_dev)
 	struct pds_vdpa_aux *vdpa_aux = auxiliary_get_drvdata(aux_dev);
 	struct device *dev = &aux_dev->dev;
 
+	pci_free_irq_vectors(vdpa_aux->padev->vf->pdev);
+
 	vdpa_aux->padev->ops->unregister_client(vdpa_aux->padev);
 
 	kfree(vdpa_aux);
diff --git a/drivers/vdpa/pds/aux_drv.h b/drivers/vdpa/pds/aux_drv.h
index 14e465944dfd..94ba7abcaa43 100644
--- a/drivers/vdpa/pds/aux_drv.h
+++ b/drivers/vdpa/pds/aux_drv.h
@@ -10,6 +10,13 @@
 struct pds_vdpa_aux {
 	struct pds_auxiliary_dev *padev;
 
+	struct vdpa_mgmt_dev vdpa_mdev;
+
+	struct pds_vdpa_ident ident;
+
+	int vf_id;
 	struct dentry *dentry;
+
+	int nintrs;
 };
 #endif /* _AUX_DRV_H_ */
diff --git a/drivers/vdpa/pds/debugfs.c b/drivers/vdpa/pds/debugfs.c
index 3c163dc7b66f..7b7e90fd6578 100644
--- a/drivers/vdpa/pds/debugfs.c
+++ b/drivers/vdpa/pds/debugfs.c
@@ -1,7 +1,10 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /* Copyright(c) 2023 Advanced Micro Devices, Inc */
 
+#include <linux/vdpa.h>
+
 #include <linux/pds/pds_core.h>
+#include <linux/pds/pds_vdpa.h>
 #include <linux/pds/pds_auxbus.h>
 
 #include "aux_drv.h"
diff --git a/drivers/vdpa/pds/vdpa_dev.c b/drivers/vdpa/pds/vdpa_dev.c
new file mode 100644
index 000000000000..bd840688503c
--- /dev/null
+++ b/drivers/vdpa/pds/vdpa_dev.c
@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2023 Advanced Micro Devices, Inc */
+
+#include <linux/pci.h>
+#include <linux/vdpa.h>
+#include <uapi/linux/vdpa.h>
+
+#include <linux/pds/pds_core.h>
+#include <linux/pds/pds_adminq.h>
+#include <linux/pds/pds_auxbus.h>
+#include <linux/pds/pds_vdpa.h>
+
+#include "vdpa_dev.h"
+#include "aux_drv.h"
+
+static struct virtio_device_id pds_vdpa_id_table[] = {
+	{VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID},
+	{0},
+};
+
+static int pds_vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
+			    const struct vdpa_dev_set_config *add_config)
+{
+	return -EOPNOTSUPP;
+}
+
+static void pds_vdpa_dev_del(struct vdpa_mgmt_dev *mdev,
+			     struct vdpa_device *vdpa_dev)
+{
+}
+
+static const struct vdpa_mgmtdev_ops pds_vdpa_mgmt_dev_ops = {
+	.dev_add = pds_vdpa_dev_add,
+	.dev_del = pds_vdpa_dev_del
+};
+
+int pds_vdpa_get_mgmt_info(struct pds_vdpa_aux *vdpa_aux)
+{
+	struct pds_vdpa_ident_cmd ident_cmd = {
+		.opcode = PDS_VDPA_CMD_IDENT,
+		.vf_id = cpu_to_le16(vdpa_aux->vf_id),
+	};
+	struct pds_vdpa_comp ident_comp = {0};
+	struct vdpa_mgmt_dev *mgmt;
+	struct device *pf_dev;
+	struct pci_dev *pdev;
+	dma_addr_t ident_pa;
+	struct device *dev;
+	u16 max_vqs;
+	int err;
+
+	dev = &vdpa_aux->padev->aux_dev.dev;
+	pdev = vdpa_aux->padev->vf->pdev;
+	mgmt = &vdpa_aux->vdpa_mdev;
+
+	/* Get resource info through the PF's adminq.  It is a block of info,
+	 * so we need to map some memory for PF to make available to the
+	 * firmware for writing the data.
+	 */
+	pf_dev = vdpa_aux->padev->pf->dev;
+	ident_pa = dma_map_single(pf_dev, &vdpa_aux->ident,
+				  sizeof(vdpa_aux->ident), DMA_FROM_DEVICE);
+	if (dma_mapping_error(pf_dev, ident_pa)) {
+		dev_err(dev, "Failed to map ident space\n");
+		return -ENOMEM;
+	}
+
+	ident_cmd.ident_pa = cpu_to_le64(ident_pa);
+	ident_cmd.len = cpu_to_le32(sizeof(vdpa_aux->ident));
+	err = vdpa_aux->padev->ops->adminq_cmd(vdpa_aux->padev,
+					       (union pds_core_adminq_cmd *)&ident_cmd,
+					       sizeof(ident_cmd),
+					       (union pds_core_adminq_comp *)&ident_comp,
+					       0);
+	dma_unmap_single(pf_dev, ident_pa,
+			 sizeof(vdpa_aux->ident), DMA_FROM_DEVICE);
+	if (err) {
+		dev_err(dev, "Failed to ident hw, status %d: %pe\n",
+			ident_comp.status, ERR_PTR(err));
+		return err;
+	}
+
+	max_vqs = le16_to_cpu(vdpa_aux->ident.max_vqs);
+	mgmt->max_supported_vqs = min_t(u16, PDS_VDPA_MAX_QUEUES, max_vqs);
+	if (max_vqs > PDS_VDPA_MAX_QUEUES)
+		dev_info(dev, "FYI - Device supports more vqs (%d) than driver (%d)\n",
+			 max_vqs, PDS_VDPA_MAX_QUEUES);
+
+	mgmt->ops = &pds_vdpa_mgmt_dev_ops;
+	mgmt->id_table = pds_vdpa_id_table;
+	mgmt->device = dev;
+	mgmt->supported_features = le64_to_cpu(vdpa_aux->ident.hw_features);
+	mgmt->config_attr_mask = BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MACADDR);
+	mgmt->config_attr_mask |= BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MAX_VQP);
+
+	/* Set up interrupts now that we know how many we might want
+	 * each gets one, than add another for a control queue if supported
+	 */
+	vdpa_aux->nintrs = mgmt->max_supported_vqs;
+	if (mgmt->supported_features & BIT_ULL(VIRTIO_NET_F_CTRL_VQ))
+		vdpa_aux->nintrs++;
+
+	err = pci_alloc_irq_vectors(pdev, vdpa_aux->nintrs, vdpa_aux->nintrs,
+				    PCI_IRQ_MSIX);
+	if (err < 0) {
+		dev_err(dev, "Couldn't get %d msix vectors: %pe\n",
+			vdpa_aux->nintrs, ERR_PTR(err));
+		return err;
+	}
+	vdpa_aux->nintrs = err;
+
+	return 0;
+}
diff --git a/drivers/vdpa/pds/vdpa_dev.h b/drivers/vdpa/pds/vdpa_dev.h
new file mode 100644
index 000000000000..97fab833a0aa
--- /dev/null
+++ b/drivers/vdpa/pds/vdpa_dev.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright(c) 2023 Advanced Micro Devices, Inc */
+
+#ifndef _VDPA_DEV_H_
+#define _VDPA_DEV_H_
+
+#define PDS_VDPA_MAX_QUEUES	65
+
+struct pds_vdpa_device {
+	struct vdpa_device vdpa_dev;
+	struct pds_vdpa_aux *vdpa_aux;
+};
+
+int pds_vdpa_get_mgmt_info(struct pds_vdpa_aux *vdpa_aux);
+#endif /* _VDPA_DEV_H_ */
diff --git a/include/linux/pds/pds_vdpa.h b/include/linux/pds/pds_vdpa.h
index b5154e3b298e..3f7c08551163 100644
--- a/include/linux/pds/pds_vdpa.h
+++ b/include/linux/pds/pds_vdpa.h
@@ -9,4 +9,96 @@
 #define PDS_DEV_TYPE_VDPA_STR	"vDPA"
 #define PDS_VDPA_DEV_NAME	PDS_CORE_DRV_NAME "." PDS_DEV_TYPE_VDPA_STR
 
+/*
+ * enum pds_vdpa_cmd_opcode - vDPA Device commands
+ */
+enum pds_vdpa_cmd_opcode {
+	PDS_VDPA_CMD_INIT		= 48,
+	PDS_VDPA_CMD_IDENT		= 49,
+	PDS_VDPA_CMD_RESET		= 51,
+	PDS_VDPA_CMD_VQ_RESET		= 52,
+	PDS_VDPA_CMD_VQ_INIT		= 53,
+	PDS_VDPA_CMD_STATUS_UPDATE	= 54,
+	PDS_VDPA_CMD_SET_FEATURES	= 55,
+	PDS_VDPA_CMD_SET_ATTR		= 56,
+	PDS_VDPA_CMD_VQ_SET_STATE	= 57,
+	PDS_VDPA_CMD_VQ_GET_STATE	= 58,
+};
+
+/**
+ * struct pds_vdpa_cmd - generic command
+ * @opcode:	Opcode
+ * @vdpa_index:	Index for vdpa subdevice
+ * @vf_id:	VF id
+ */
+struct pds_vdpa_cmd {
+	u8     opcode;
+	u8     vdpa_index;
+	__le16 vf_id;
+};
+
+/**
+ * struct pds_vdpa_comp - generic command completion
+ * @status:	Status of the command (enum pds_core_status_code)
+ * @rsvd:	Word boundary padding
+ * @color:	Color bit
+ */
+struct pds_vdpa_comp {
+	u8 status;
+	u8 rsvd[14];
+	u8 color;
+};
+
+/**
+ * struct pds_vdpa_init_cmd - INIT command
+ * @opcode:	Opcode PDS_VDPA_CMD_INIT
+ * @vdpa_index: Index for vdpa subdevice
+ * @vf_id:	VF id
+ * @len:	length of config info DMA space
+ * @config_pa:	address for DMA of virtio config struct
+ */
+struct pds_vdpa_init_cmd {
+	u8     opcode;
+	u8     vdpa_index;
+	__le16 vf_id;
+	__le32 len;
+	__le64 config_pa;
+};
+
+/**
+ * struct pds_vdpa_ident - vDPA identification data
+ * @hw_features:	vDPA features supported by device
+ * @max_vqs:		max queues available (2 queues for a single queuepair)
+ * @max_qlen:		log(2) of maximum number of descriptors
+ * @min_qlen:		log(2) of minimum number of descriptors
+ *
+ * This struct is used in a DMA block that is set up for the PDS_VDPA_CMD_IDENT
+ * transaction.  Set up the DMA block and send the address in the IDENT cmd
+ * data, the DSC will write the ident information, then we can remove the DMA
+ * block after reading the answer.  If the completion status is 0, then there
+ * is valid information, else there was an error and the data should be invalid.
+ */
+struct pds_vdpa_ident {
+	__le64 hw_features;
+	__le16 max_vqs;
+	__le16 max_qlen;
+	__le16 min_qlen;
+};
+
+/**
+ * struct pds_vdpa_ident_cmd - IDENT command
+ * @opcode:	Opcode PDS_VDPA_CMD_IDENT
+ * @rsvd:       Word boundary padding
+ * @vf_id:	VF id
+ * @len:	length of ident info DMA space
+ * @ident_pa:	address for DMA of ident info (struct pds_vdpa_ident)
+ *			only used for this transaction, then forgotten by DSC
+ */
+struct pds_vdpa_ident_cmd {
+	u8     opcode;
+	u8     rsvd;
+	__le16 vf_id;
+	__le32 len;
+	__le64 ident_pa;
+};
 #endif /* _PDS_VDPA_IF_H_ */
-- 
2.17.1