[PATCH net-next v2 02/14] sfc: implement MCDI interface for vDPA operations

[Gautam Dawar]

Implement functions to perform vDPA operations like creating and
removing virtqueues, getting doorbell register offset etc. using
the MCDI interface with FW.

Signed-off-by: Gautam Dawar <gautam.dawar@xxxxxxx>
---
 drivers/net/ethernet/sfc/Kconfig      |   8 +
 drivers/net/ethernet/sfc/Makefile     |   1 +
 drivers/net/ethernet/sfc/ef100_vdpa.h |  32 +++
 drivers/net/ethernet/sfc/mcdi.h       |   4 +
 drivers/net/ethernet/sfc/mcdi_vdpa.c  | 267 ++++++++++++++++++++++++++
 drivers/net/ethernet/sfc/mcdi_vdpa.h  |  83 ++++++++
 6 files changed, 395 insertions(+)
 create mode 100644 drivers/net/ethernet/sfc/ef100_vdpa.h
 create mode 100644 drivers/net/ethernet/sfc/mcdi_vdpa.c
 create mode 100644 drivers/net/ethernet/sfc/mcdi_vdpa.h

diff --git a/drivers/net/ethernet/sfc/Kconfig b/drivers/net/ethernet/sfc/Kconfig
index 4af36ba8906b..0b5091e26cd1 100644
--- a/drivers/net/ethernet/sfc/Kconfig
+++ b/drivers/net/ethernet/sfc/Kconfig
@@ -64,6 +64,14 @@ config SFC_MCDI_LOGGING
 	  Driver-Interface) commands and responses, allowing debugging of
 	  driver/firmware interaction.  The tracing is actually enabled by
 	  a sysfs file 'mcdi_logging' under the PCI device.
+config SFC_VDPA
+	bool "Solarflare EF100-family VDPA support"
+	depends on SFC && VDPA && SFC_SRIOV
+	default y
+	help
+	  This enables support for the virtio data path acceleration (vDPA).
+	  vDPA device's datapath complies with the virtio specification,
+	  but control path is vendor specific.
 
 source "drivers/net/ethernet/sfc/falcon/Kconfig"
 source "drivers/net/ethernet/sfc/siena/Kconfig"
diff --git a/drivers/net/ethernet/sfc/Makefile b/drivers/net/ethernet/sfc/Makefile
index 55b9c73cd8ef..fb94fe3a9dfc 100644
--- a/drivers/net/ethernet/sfc/Makefile
+++ b/drivers/net/ethernet/sfc/Makefile
@@ -12,6 +12,7 @@ sfc-$(CONFIG_SFC_MTD)	+= mtd.o
 sfc-$(CONFIG_SFC_SRIOV)	+= sriov.o ef10_sriov.o ef100_sriov.o ef100_rep.o \
                            mae.o tc.o tc_bindings.o tc_counters.o
 
+sfc-$(CONFIG_SFC_VDPA)	+= mcdi_vdpa.o
 obj-$(CONFIG_SFC)	+= sfc.o
 
 obj-$(CONFIG_SFC_FALCON) += falcon/
diff --git a/drivers/net/ethernet/sfc/ef100_vdpa.h b/drivers/net/ethernet/sfc/ef100_vdpa.h
new file mode 100644
index 000000000000..f6564448d0c7
--- /dev/null
+++ b/drivers/net/ethernet/sfc/ef100_vdpa.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Driver for Xilinx network controllers and boards
+ * Copyright (C) 2020-2022, Xilinx, Inc.
+ * Copyright (C) 2022, Advanced Micro Devices, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation, incorporated herein by reference.
+ */
+
+#ifndef __EF100_VDPA_H__
+#define __EF100_VDPA_H__
+
+#include <linux/vdpa.h>
+#include <uapi/linux/virtio_net.h>
+#include "net_driver.h"
+#include "ef100_nic.h"
+
+#if defined(CONFIG_SFC_VDPA)
+
+enum ef100_vdpa_device_type {
+	EF100_VDPA_DEVICE_TYPE_NET,
+};
+
+enum ef100_vdpa_vq_type {
+	EF100_VDPA_VQ_TYPE_NET_RXQ,
+	EF100_VDPA_VQ_TYPE_NET_TXQ,
+	EF100_VDPA_VQ_NTYPES
+};
+
+#endif /* CONFIG_SFC_VDPA */
+#endif /* __EF100_VDPA_H__ */
diff --git a/drivers/net/ethernet/sfc/mcdi.h b/drivers/net/ethernet/sfc/mcdi.h
index b139b76febff..dafab52aaef7 100644
--- a/drivers/net/ethernet/sfc/mcdi.h
+++ b/drivers/net/ethernet/sfc/mcdi.h
@@ -214,6 +214,10 @@ void efx_mcdi_sensor_event(struct efx_nic *efx, efx_qword_t *ev);
 #define _MCDI_STRUCT_DWORD(_buf, _field)				\
 	((_buf) + (_MCDI_CHECK_ALIGN(_field ## _OFST, 4) >> 2))
 
+#define MCDI_SET_BYTE(_buf, _field, _value) do {			\
+	BUILD_BUG_ON(MC_CMD_ ## _field ## _LEN != 1);			\
+	*(u8 *)MCDI_PTR(_buf, _field) = _value;				\
+	} while (0)
 #define MCDI_STRUCT_SET_BYTE(_buf, _field, _value) do {			\
 	BUILD_BUG_ON(_field ## _LEN != 1);				\
 	*(u8 *)MCDI_STRUCT_PTR(_buf, _field) = _value;			\
diff --git a/drivers/net/ethernet/sfc/mcdi_vdpa.c b/drivers/net/ethernet/sfc/mcdi_vdpa.c
new file mode 100644
index 000000000000..b9668545ca01
--- /dev/null
+++ b/drivers/net/ethernet/sfc/mcdi_vdpa.c
@@ -0,0 +1,267 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Driver for AMD network controllers and boards
+ * Copyright (C) 2023, Advanced Micro Devices, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation, incorporated herein by reference.
+ */
+
+#include <linux/vdpa.h>
+#include "ef100_vdpa.h"
+#include "efx.h"
+#include "nic.h"
+#include "mcdi_vdpa.h"
+#include "mcdi_pcol.h"
+
+/* The value of target_vf in virtio MC commands like
+ * virtqueue create, delete and get doorbell offset should
+ * contain the VF index when the calling function is a PF
+ * and VF_NULL (0xFFFF) otherwise. As the vDPA driver invokes
+ * MC commands in context of the VF, it uses VF_NULL.
+ */
+#define MC_CMD_VIRTIO_TARGET_VF_NULL 0xFFFF
+
+struct efx_vring_ctx *efx_vdpa_vring_init(struct efx_nic *efx,  u32 vi,
+					  enum ef100_vdpa_vq_type vring_type)
+{
+	struct efx_vring_ctx *vring_ctx;
+	u32 queue_cmd;
+
+	vring_ctx = kzalloc(sizeof(*vring_ctx), GFP_KERNEL);
+	if (!vring_ctx)
+		return ERR_PTR(-ENOMEM);
+
+	switch (vring_type) {
+	case EF100_VDPA_VQ_TYPE_NET_RXQ:
+		queue_cmd = MC_CMD_VIRTIO_INIT_QUEUE_REQ_NET_RXQ;
+		break;
+	case EF100_VDPA_VQ_TYPE_NET_TXQ:
+		queue_cmd = MC_CMD_VIRTIO_INIT_QUEUE_REQ_NET_TXQ;
+		break;
+	default:
+		pci_err(efx->pci_dev,
+			"%s: Invalid Queue type %u\n", __func__, vring_type);
+		kfree(vring_ctx);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	vring_ctx->efx = efx;
+	vring_ctx->vf_index = MC_CMD_VIRTIO_TARGET_VF_NULL;
+	vring_ctx->vi_index = vi;
+	vring_ctx->mcdi_vring_type = queue_cmd;
+	return vring_ctx;
+}
+
+void efx_vdpa_vring_fini(struct efx_vring_ctx *vring_ctx)
+{
+	kfree(vring_ctx);
+}
+
+int efx_vdpa_get_features(struct efx_nic *efx,
+			  enum ef100_vdpa_device_type type,
+			  u64 *features)
+{
+	MCDI_DECLARE_BUF(outbuf, MC_CMD_VIRTIO_GET_FEATURES_OUT_LEN);
+	MCDI_DECLARE_BUF(inbuf, MC_CMD_VIRTIO_GET_FEATURES_IN_LEN);
+	u32 high_val, low_val;
+	ssize_t outlen;
+	u32 dev_type;
+	int rc;
+
+	if (!efx) {
+		pci_err(efx->pci_dev, "%s: Invalid NIC pointer\n", __func__);
+		return -EINVAL;
+	}
+	switch (type) {
+	case EF100_VDPA_DEVICE_TYPE_NET:
+		dev_type = MC_CMD_VIRTIO_GET_FEATURES_IN_NET;
+		break;
+	default:
+		pci_err(efx->pci_dev,
+			"%s: Device type %d not supported\n", __func__, type);
+		return -EINVAL;
+	}
+	MCDI_SET_DWORD(inbuf, VIRTIO_GET_FEATURES_IN_DEVICE_ID, dev_type);
+	rc = efx_mcdi_rpc(efx, MC_CMD_VIRTIO_GET_FEATURES, inbuf, sizeof(inbuf),
+			  outbuf, sizeof(outbuf), &outlen);
+	if (rc)
+		return rc;
+	if (outlen < MC_CMD_VIRTIO_GET_FEATURES_OUT_LEN)
+		return -EIO;
+	low_val = MCDI_DWORD(outbuf, VIRTIO_GET_FEATURES_OUT_FEATURES_LO);
+	high_val = MCDI_DWORD(outbuf, VIRTIO_GET_FEATURES_OUT_FEATURES_HI);
+	*features = ((u64)high_val << 32) | low_val;
+	return 0;
+}
+
+int efx_vdpa_verify_features(struct efx_nic *efx,
+			     enum ef100_vdpa_device_type type, u64 features)
+{
+	MCDI_DECLARE_BUF(inbuf, MC_CMD_VIRTIO_TEST_FEATURES_IN_LEN);
+	u32 dev_type;
+	int rc;
+
+	BUILD_BUG_ON(MC_CMD_VIRTIO_TEST_FEATURES_OUT_LEN != 0);
+	switch (type) {
+	case EF100_VDPA_DEVICE_TYPE_NET:
+		dev_type = MC_CMD_VIRTIO_GET_FEATURES_IN_NET;
+		break;
+	default:
+		pci_err(efx->pci_dev,
+			"%s: Device type %d not supported\n", __func__, type);
+		return -EINVAL;
+	}
+	MCDI_SET_DWORD(inbuf, VIRTIO_TEST_FEATURES_IN_DEVICE_ID, dev_type);
+	MCDI_SET_DWORD(inbuf, VIRTIO_TEST_FEATURES_IN_FEATURES_LO, features);
+	MCDI_SET_DWORD(inbuf, VIRTIO_TEST_FEATURES_IN_FEATURES_HI,
+		       features >> 32);
+	rc = efx_mcdi_rpc(efx, MC_CMD_VIRTIO_TEST_FEATURES, inbuf,
+			  sizeof(inbuf), NULL, 0, NULL);
+	return rc;
+}
+
+int efx_vdpa_vring_create(struct efx_vring_ctx *vring_ctx,
+			  struct efx_vring_cfg *vring_cfg,
+			  struct efx_vring_dyn_cfg *vring_dyn_cfg)
+{
+	MCDI_DECLARE_BUF(inbuf, MC_CMD_VIRTIO_INIT_QUEUE_REQ_LEN);
+	struct efx_nic *efx = vring_ctx->efx;
+	int rc;
+
+	BUILD_BUG_ON(MC_CMD_VIRTIO_INIT_QUEUE_RESP_LEN != 0);
+
+	MCDI_SET_BYTE(inbuf, VIRTIO_INIT_QUEUE_REQ_QUEUE_TYPE,
+		      vring_ctx->mcdi_vring_type);
+	MCDI_SET_WORD(inbuf, VIRTIO_INIT_QUEUE_REQ_TARGET_VF,
+		      vring_ctx->vf_index);
+	MCDI_SET_DWORD(inbuf, VIRTIO_INIT_QUEUE_REQ_INSTANCE,
+		       vring_ctx->vi_index);
+
+	MCDI_SET_DWORD(inbuf, VIRTIO_INIT_QUEUE_REQ_SIZE, vring_cfg->size);
+	MCDI_SET_DWORD(inbuf, VIRTIO_INIT_QUEUE_REQ_DESC_TBL_ADDR_LO,
+		       vring_cfg->desc);
+	MCDI_SET_DWORD(inbuf, VIRTIO_INIT_QUEUE_REQ_DESC_TBL_ADDR_HI,
+		       vring_cfg->desc >> 32);
+	MCDI_SET_DWORD(inbuf, VIRTIO_INIT_QUEUE_REQ_AVAIL_RING_ADDR_LO,
+		       vring_cfg->avail);
+	MCDI_SET_DWORD(inbuf, VIRTIO_INIT_QUEUE_REQ_AVAIL_RING_ADDR_HI,
+		       vring_cfg->avail >> 32);
+	MCDI_SET_DWORD(inbuf, VIRTIO_INIT_QUEUE_REQ_USED_RING_ADDR_LO,
+		       vring_cfg->used);
+	MCDI_SET_DWORD(inbuf, VIRTIO_INIT_QUEUE_REQ_USED_RING_ADDR_HI,
+		       vring_cfg->used >> 32);
+	MCDI_SET_WORD(inbuf, VIRTIO_INIT_QUEUE_REQ_MSIX_VECTOR,
+		      vring_cfg->msix_vector);
+	MCDI_SET_DWORD(inbuf, VIRTIO_INIT_QUEUE_REQ_FEATURES_LO,
+		       vring_cfg->features);
+	MCDI_SET_DWORD(inbuf, VIRTIO_INIT_QUEUE_REQ_FEATURES_HI,
+		       vring_cfg->features >> 32);
+
+	if (vring_dyn_cfg) {
+		MCDI_SET_DWORD(inbuf, VIRTIO_INIT_QUEUE_REQ_INITIAL_PIDX,
+			       vring_dyn_cfg->avail_idx);
+		MCDI_SET_DWORD(inbuf, VIRTIO_INIT_QUEUE_REQ_INITIAL_CIDX,
+			       vring_dyn_cfg->used_idx);
+	}
+	MCDI_SET_DWORD(inbuf, VIRTIO_INIT_QUEUE_REQ_MPORT_SELECTOR,
+		       MAE_MPORT_SELECTOR_ASSIGNED);
+
+	rc = efx_mcdi_rpc(efx, MC_CMD_VIRTIO_INIT_QUEUE, inbuf, sizeof(inbuf),
+			  NULL, 0, NULL);
+	return rc;
+}
+
+int efx_vdpa_vring_destroy(struct efx_vring_ctx *vring_ctx,
+			   struct efx_vring_dyn_cfg *vring_dyn_cfg)
+{
+	MCDI_DECLARE_BUF(outbuf, MC_CMD_VIRTIO_FINI_QUEUE_RESP_LEN);
+	MCDI_DECLARE_BUF(inbuf, MC_CMD_VIRTIO_FINI_QUEUE_REQ_LEN);
+	struct efx_nic *efx = vring_ctx->efx;
+	ssize_t outlen;
+	int rc;
+
+	MCDI_SET_BYTE(inbuf, VIRTIO_FINI_QUEUE_REQ_QUEUE_TYPE,
+		      vring_ctx->mcdi_vring_type);
+	MCDI_SET_WORD(inbuf, VIRTIO_INIT_QUEUE_REQ_TARGET_VF,
+		      vring_ctx->vf_index);
+	MCDI_SET_DWORD(inbuf, VIRTIO_INIT_QUEUE_REQ_INSTANCE,
+		       vring_ctx->vi_index);
+	rc = efx_mcdi_rpc(efx, MC_CMD_VIRTIO_FINI_QUEUE, inbuf, sizeof(inbuf),
+			  outbuf, sizeof(outbuf), &outlen);
+
+	if (rc)
+		return rc;
+
+	if (outlen < MC_CMD_VIRTIO_FINI_QUEUE_RESP_LEN)
+		return -EIO;
+
+	if (vring_dyn_cfg) {
+		vring_dyn_cfg->avail_idx = MCDI_DWORD(outbuf,
+						      VIRTIO_FINI_QUEUE_RESP_FINAL_PIDX);
+		vring_dyn_cfg->used_idx = MCDI_DWORD(outbuf,
+						     VIRTIO_FINI_QUEUE_RESP_FINAL_CIDX);
+	}
+
+	return 0;
+}
+
+int efx_vdpa_get_doorbell_offset(struct efx_vring_ctx *vring_ctx,
+				 u32 *offset)
+{
+	MCDI_DECLARE_BUF(outbuf, MC_CMD_VIRTIO_GET_NET_DOORBELL_OFFSET_RESP_LEN);
+	MCDI_DECLARE_BUF(inbuf, MC_CMD_VIRTIO_GET_DOORBELL_OFFSET_REQ_LEN);
+	struct efx_nic *efx = vring_ctx->efx;
+	ssize_t outlen;
+	int rc;
+
+	if (vring_ctx->mcdi_vring_type != MC_CMD_VIRTIO_INIT_QUEUE_REQ_NET_RXQ &&
+	    vring_ctx->mcdi_vring_type != MC_CMD_VIRTIO_INIT_QUEUE_REQ_NET_TXQ) {
+		pci_err(efx->pci_dev,
+			"%s: Invalid Queue type %u\n",
+			__func__, vring_ctx->mcdi_vring_type);
+		return -EINVAL;
+	}
+
+	MCDI_SET_BYTE(inbuf, VIRTIO_GET_DOORBELL_OFFSET_REQ_DEVICE_ID,
+		      MC_CMD_VIRTIO_GET_FEATURES_IN_NET);
+	MCDI_SET_WORD(inbuf, VIRTIO_GET_DOORBELL_OFFSET_REQ_TARGET_VF,
+		      vring_ctx->vf_index);
+	MCDI_SET_DWORD(inbuf, VIRTIO_GET_DOORBELL_OFFSET_REQ_INSTANCE,
+		       vring_ctx->vi_index);
+
+	rc = efx_mcdi_rpc(efx, MC_CMD_VIRTIO_GET_DOORBELL_OFFSET, inbuf,
+			  sizeof(inbuf), outbuf, sizeof(outbuf), &outlen);
+	if (rc)
+		return rc;
+
+	if (outlen < MC_CMD_VIRTIO_GET_NET_DOORBELL_OFFSET_RESP_LEN)
+		return -EIO;
+	if (vring_ctx->mcdi_vring_type == MC_CMD_VIRTIO_INIT_QUEUE_REQ_NET_RXQ)
+		*offset = MCDI_DWORD(outbuf,
+				     VIRTIO_GET_NET_DOORBELL_OFFSET_RESP_RX_DBL_OFFSET);
+	else
+		*offset = MCDI_DWORD(outbuf,
+				     VIRTIO_GET_NET_DOORBELL_OFFSET_RESP_TX_DBL_OFFSET);
+
+	return 0;
+}
+
+int efx_vdpa_get_mtu(struct efx_nic *efx, u16 *mtu)
+{
+	MCDI_DECLARE_BUF(outbuf, MC_CMD_SET_MAC_V2_OUT_LEN);
+	MCDI_DECLARE_BUF(inbuf, MC_CMD_SET_MAC_EXT_IN_LEN);
+	ssize_t outlen;
+	int rc;
+
+	MCDI_SET_DWORD(inbuf, SET_MAC_EXT_IN_CONTROL, 0);
+	rc =  efx_mcdi_rpc(efx, MC_CMD_SET_MAC, inbuf, sizeof(inbuf),
+			   outbuf, sizeof(outbuf), &outlen);
+	if (rc)
+		return rc;
+	if (outlen < MC_CMD_SET_MAC_V2_OUT_LEN)
+		return -EIO;
+
+	*mtu = MCDI_DWORD(outbuf, SET_MAC_V2_OUT_MTU);
+	return 0;
+}
diff --git a/drivers/net/ethernet/sfc/mcdi_vdpa.h b/drivers/net/ethernet/sfc/mcdi_vdpa.h
new file mode 100644
index 000000000000..d2bb0152d9c3
--- /dev/null
+++ b/drivers/net/ethernet/sfc/mcdi_vdpa.h
@@ -0,0 +1,83 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Driver for AMD network controllers and boards
+ * Copyright (C) 2023, Advanced Micro Devices, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation, incorporated herein by reference.
+ */
+
+#ifndef EFX_MCDI_VDPA_H
+#define EFX_MCDI_VDPA_H
+
+#if defined(CONFIG_SFC_VDPA)
+#include "mcdi.h"
+
+/**
+ * struct efx_vring_ctx: The vring context
+ *
+ * @efx: pointer of the VF's efx_nic object
+ * @vf_index: VF index of the vDPA VF
+ * @vi_index: vi index to be used for queue creation
+ * @mcdi_vring_type: corresponding MCDI vring type
+ */
+struct efx_vring_ctx {
+	struct efx_nic *efx;
+	u32 vf_index;
+	u32 vi_index;
+	u32 mcdi_vring_type;
+};
+
+/**
+ * struct efx_vring_cfg: Configuration for vring creation
+ *
+ * @desc: Descriptor area address of the vring
+ * @avail: Available area address of the vring
+ * @used: Device area address of the vring
+ * @size: Queue size, in entries. Must be a power of two
+ * @msix_vector: msix vector address for the queue
+ * @features: negotiated feature bits
+ */
+struct efx_vring_cfg {
+	u64 desc;
+	u64 avail;
+	u64 used;
+	u32 size;
+	u16 msix_vector;
+	u64 features;
+};
+
+/**
+ * struct efx_vring_dyn_cfg - dynamic vring configuration
+ *
+ * @avail_idx: last available index of the vring
+ * @used_idx: last used index of the vring
+ */
+struct efx_vring_dyn_cfg {
+	u32 avail_idx;
+	u32 used_idx;
+};
+
+int efx_vdpa_get_features(struct efx_nic *efx, enum ef100_vdpa_device_type type,
+			  u64 *featuresp);
+
+int efx_vdpa_verify_features(struct efx_nic *efx,
+			     enum ef100_vdpa_device_type type, u64 features);
+
+struct efx_vring_ctx *efx_vdpa_vring_init(struct efx_nic *efx, u32 vi,
+					  enum ef100_vdpa_vq_type vring_type);
+
+void efx_vdpa_vring_fini(struct efx_vring_ctx *vring_ctx);
+
+int efx_vdpa_vring_create(struct efx_vring_ctx *vring_ctx,
+			  struct efx_vring_cfg *vring_cfg,
+			  struct efx_vring_dyn_cfg *vring_dyn_cfg);
+
+int efx_vdpa_vring_destroy(struct efx_vring_ctx *vring_ctx,
+			   struct efx_vring_dyn_cfg *vring_dyn_cfg);
+
+int efx_vdpa_get_doorbell_offset(struct efx_vring_ctx *vring_ctx,
+				 u32 *offsetp);
+int efx_vdpa_get_mtu(struct efx_nic *efx, u16 *mtu);
+#endif
+#endif
-- 
2.30.1