vdpa/mlx5: Add support library for mlx5 VDPA implementation

Following patches introduce VDPA network driver for Mellanox Connectx6
devices. This patch provides functionality that will be used by those
patches.

Reviewed-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Eli Cohen <eli@mellanox.com>
Link: https://lore.kernel.org/r/20200804162048.22587-11-eli@mellanox.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/vdpa/Kconfig

@@ -28,4 +28,13 @@ config IFCVF
 	  To compile this driver as a module, choose M here: the module will
 	  be called ifcvf.
 
+config MLX5_VDPA
+	bool "MLX5 VDPA support library for ConnectX devices"
+	depends on MLX5_CORE
+	default n
+	help
+	  Support library for Mellanox VDPA drivers. Provides code that is
+	  common for all types of VDPA drivers. The following drivers are planned:
+	  net, block.
+
 endif # VDPA

drivers/vdpa/Makefile

@@ -2,3 +2,4 @@
 obj-$(CONFIG_VDPA) += vdpa.o
 obj-$(CONFIG_VDPA_SIM) += vdpa_sim/
 obj-$(CONFIG_IFCVF)    += ifcvf/
+obj-$(CONFIG_MLX5_VDPA) += mlx5/

drivers/vdpa/mlx5/Makefile

@@ -0,0 +1 @@
+obj-$(CONFIG_MLX5_VDPA) += core/resources.o

drivers/vdpa/mlx5/core/Makefile

@@ -0,0 +1 @@
+obj-y += resources.o

drivers/vdpa/mlx5/core/mlx5_vdpa.h

@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
+/* Copyright (c) 2020 Mellanox Technologies Ltd. */
+
+#ifndef __MLX5_VDPA_H__
+#define __MLX5_VDPA_H__
+
+#include <linux/vdpa.h>
+#include <linux/mlx5/driver.h>
+
+struct mlx5_vdpa_resources {
+	u32 pdn;
+	struct mlx5_uars_page *uar;
+	void __iomem *kick_addr;
+	u16 uid;
+	u32 null_mkey;
+	bool valid;
+};
+
+struct mlx5_vdpa_dev {
+	struct vdpa_device vdev;
+	struct mlx5_core_dev *mdev;
+	struct mlx5_vdpa_resources res;
+
+	u64 mlx_features;
+	u64 actual_features;
+	u8 status;
+	u32 max_vqs;
+	u32 generation;
+};
+
+int mlx5_vdpa_alloc_pd(struct mlx5_vdpa_dev *dev, u32 *pdn, u16 uid);
+int mlx5_vdpa_dealloc_pd(struct mlx5_vdpa_dev *dev, u32 pdn, u16 uid);
+int mlx5_vdpa_get_null_mkey(struct mlx5_vdpa_dev *dev, u32 *null_mkey);
+int mlx5_vdpa_create_tis(struct mlx5_vdpa_dev *mvdev, void *in, u32 *tisn);
+void mlx5_vdpa_destroy_tis(struct mlx5_vdpa_dev *mvdev, u32 tisn);
+int mlx5_vdpa_create_rqt(struct mlx5_vdpa_dev *mvdev, void *in, int inlen, u32 *rqtn);
+void mlx5_vdpa_destroy_rqt(struct mlx5_vdpa_dev *mvdev, u32 rqtn);
+int mlx5_vdpa_create_tir(struct mlx5_vdpa_dev *mvdev, void *in, u32 *tirn);
+void mlx5_vdpa_destroy_tir(struct mlx5_vdpa_dev *mvdev, u32 tirn);
+int mlx5_vdpa_alloc_transport_domain(struct mlx5_vdpa_dev *mvdev, u32 *tdn);
+void mlx5_vdpa_dealloc_transport_domain(struct mlx5_vdpa_dev *mvdev, u32 tdn);
+int mlx5_vdpa_alloc_resources(struct mlx5_vdpa_dev *mvdev);
+void mlx5_vdpa_free_resources(struct mlx5_vdpa_dev *mvdev);
+
+#define mlx5_vdpa_warn(__dev, format, ...)                                                         \
+	dev_warn((__dev)->mdev->device, "%s:%d:(pid %d) warning: " format, __func__, __LINE__,     \
+		 current->pid, ##__VA_ARGS__)
+
+#define mlx5_vdpa_info(__dev, format, ...)                                                         \
+	dev_info((__dev)->mdev->device, "%s:%d:(pid %d): " format, __func__, __LINE__,             \
+		 current->pid, ##__VA_ARGS__)
+
+#define mlx5_vdpa_dbg(__dev, format, ...)                                                          \
+	dev_debug((__dev)->mdev->device, "%s:%d:(pid %d): " format, __func__, __LINE__,            \
+		  current->pid, ##__VA_ARGS__)
+
+#endif /* __MLX5_VDPA_H__ */

drivers/vdpa/mlx5/core/resources.c

@@ -0,0 +1,281 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+/* Copyright (c) 2020 Mellanox Technologies Ltd. */
+
+#include <linux/mlx5/driver.h>
+#include "mlx5_vdpa.h"
+
+static int alloc_pd(struct mlx5_vdpa_dev *dev, u32 *pdn, u16 uid)
+{
+	struct mlx5_core_dev *mdev = dev->mdev;
+
+	u32 out[MLX5_ST_SZ_DW(alloc_pd_out)] = {};
+	u32 in[MLX5_ST_SZ_DW(alloc_pd_in)] = {};
+	int err;
+
+	MLX5_SET(alloc_pd_in, in, opcode, MLX5_CMD_OP_ALLOC_PD);
+	MLX5_SET(alloc_pd_in, in, uid, uid);
+
+	err = mlx5_cmd_exec_inout(mdev, alloc_pd, in, out);
+	if (!err)
+		*pdn = MLX5_GET(alloc_pd_out, out, pd);
+
+	return err;
+}
+
+static int dealloc_pd(struct mlx5_vdpa_dev *dev, u32 pdn, u16 uid)
+{
+	u32 in[MLX5_ST_SZ_DW(dealloc_pd_in)] = {};
+	struct mlx5_core_dev *mdev = dev->mdev;
+
+	MLX5_SET(dealloc_pd_in, in, opcode, MLX5_CMD_OP_DEALLOC_PD);
+	MLX5_SET(dealloc_pd_in, in, pd, pdn);
+	MLX5_SET(dealloc_pd_in, in, uid, uid);
+	return mlx5_cmd_exec_in(mdev, dealloc_pd, in);
+}
+
+static int get_null_mkey(struct mlx5_vdpa_dev *dev, u32 *null_mkey)
+{
+	u32 out[MLX5_ST_SZ_DW(query_special_contexts_out)] = {};
+	u32 in[MLX5_ST_SZ_DW(query_special_contexts_in)] = {};
+	struct mlx5_core_dev *mdev = dev->mdev;
+	int err;
+
+	MLX5_SET(query_special_contexts_in, in, opcode, MLX5_CMD_OP_QUERY_SPECIAL_CONTEXTS);
+	err = mlx5_cmd_exec_inout(mdev, query_special_contexts, in, out);
+	if (!err)
+		*null_mkey = MLX5_GET(query_special_contexts_out, out, null_mkey);
+	return err;
+}
+
+static int create_uctx(struct mlx5_vdpa_dev *mvdev, u16 *uid)
+{
+	u32 out[MLX5_ST_SZ_DW(create_uctx_out)] = {};
+	int inlen;
+	void *in;
+	int err;
+
+	/* 0 means not supported */
+	if (!MLX5_CAP_GEN(mvdev->mdev, log_max_uctx))
+		return -EOPNOTSUPP;
+
+	inlen = MLX5_ST_SZ_BYTES(create_uctx_in);
+	in = kzalloc(inlen, GFP_KERNEL);
+	if (!in)
+		return -ENOMEM;
+
+	MLX5_SET(create_uctx_in, in, opcode, MLX5_CMD_OP_CREATE_UCTX);
+	MLX5_SET(create_uctx_in, in, uctx.cap, MLX5_UCTX_CAP_RAW_TX);
+
+	err = mlx5_cmd_exec(mvdev->mdev, in, inlen, out, sizeof(out));
+	kfree(in);
+	if (!err)
+		*uid = MLX5_GET(create_uctx_out, out, uid);
+
+	return err;
+}
+
+static void destroy_uctx(struct mlx5_vdpa_dev *mvdev, u32 uid)
+{
+	u32 out[MLX5_ST_SZ_DW(destroy_uctx_out)] = {};
+	u32 in[MLX5_ST_SZ_DW(destroy_uctx_in)] = {};
+
+	MLX5_SET(destroy_uctx_in, in, opcode, MLX5_CMD_OP_DESTROY_UCTX);
+	MLX5_SET(destroy_uctx_in, in, uid, uid);
+
+	mlx5_cmd_exec(mvdev->mdev, in, sizeof(in), out, sizeof(out));
+}
+
+int mlx5_vdpa_create_tis(struct mlx5_vdpa_dev *mvdev, void *in, u32 *tisn)
+{
+	u32 out[MLX5_ST_SZ_DW(create_tis_out)] = {};
+	int err;
+
+	MLX5_SET(create_tis_in, in, opcode, MLX5_CMD_OP_CREATE_TIS);
+	MLX5_SET(create_tis_in, in, uid, mvdev->res.uid);
+	err = mlx5_cmd_exec_inout(mvdev->mdev, create_tis, in, out);
+	if (!err)
+		*tisn = MLX5_GET(create_tis_out, out, tisn);
+
+	return err;
+}
+
+void mlx5_vdpa_destroy_tis(struct mlx5_vdpa_dev *mvdev, u32 tisn)
+{
+	u32 in[MLX5_ST_SZ_DW(destroy_tis_in)] = {};
+
+	MLX5_SET(destroy_tis_in, in, opcode, MLX5_CMD_OP_DESTROY_TIS);
+	MLX5_SET(destroy_tis_in, in, uid, mvdev->res.uid);
+	MLX5_SET(destroy_tis_in, in, tisn, tisn);
+	mlx5_cmd_exec_in(mvdev->mdev, destroy_tis, in);
+}
+
+int mlx5_vdpa_create_rqt(struct mlx5_vdpa_dev *mvdev, void *in, int inlen, u32 *rqtn)
+{
+	u32 out[MLX5_ST_SZ_DW(create_rqt_out)] = {};
+	int err;
+
+	MLX5_SET(create_rqt_in, in, opcode, MLX5_CMD_OP_CREATE_RQT);
+	err = mlx5_cmd_exec(mvdev->mdev, in, inlen, out, sizeof(out));
+	if (!err)
+		*rqtn = MLX5_GET(create_rqt_out, out, rqtn);
+
+	return err;
+}
+
+void mlx5_vdpa_destroy_rqt(struct mlx5_vdpa_dev *mvdev, u32 rqtn)
+{
+	u32 in[MLX5_ST_SZ_DW(destroy_rqt_in)] = {};
+
+	MLX5_SET(destroy_rqt_in, in, opcode, MLX5_CMD_OP_DESTROY_RQT);
+	MLX5_SET(destroy_rqt_in, in, uid, mvdev->res.uid);
+	MLX5_SET(destroy_rqt_in, in, rqtn, rqtn);
+	mlx5_cmd_exec_in(mvdev->mdev, destroy_rqt, in);
+}
+
+int mlx5_vdpa_create_tir(struct mlx5_vdpa_dev *mvdev, void *in, u32 *tirn)
+{
+	u32 out[MLX5_ST_SZ_DW(create_tir_out)] = {};
+	int err;
+
+	MLX5_SET(create_tir_in, in, opcode, MLX5_CMD_OP_CREATE_TIR);
+	err = mlx5_cmd_exec_inout(mvdev->mdev, create_tir, in, out);
+	if (!err)
+		*tirn = MLX5_GET(create_tir_out, out, tirn);
+
+	return err;
+}
+
+void mlx5_vdpa_destroy_tir(struct mlx5_vdpa_dev *mvdev, u32 tirn)
+{
+	u32 in[MLX5_ST_SZ_DW(destroy_tir_in)] = {};
+
+	MLX5_SET(destroy_tir_in, in, opcode, MLX5_CMD_OP_DESTROY_TIR);
+	MLX5_SET(destroy_tir_in, in, uid, mvdev->res.uid);
+	MLX5_SET(destroy_tir_in, in, tirn, tirn);
+	mlx5_cmd_exec_in(mvdev->mdev, destroy_tir, in);
+}
+
+int mlx5_vdpa_alloc_transport_domain(struct mlx5_vdpa_dev *mvdev, u32 *tdn)
+{
+	u32 out[MLX5_ST_SZ_DW(alloc_transport_domain_out)] = {};
+	u32 in[MLX5_ST_SZ_DW(alloc_transport_domain_in)] = {};
+	int err;
+
+	MLX5_SET(alloc_transport_domain_in, in, opcode, MLX5_CMD_OP_ALLOC_TRANSPORT_DOMAIN);
+	MLX5_SET(alloc_transport_domain_in, in, uid, mvdev->res.uid);
+
+	err = mlx5_cmd_exec_inout(mvdev->mdev, alloc_transport_domain, in, out);
+	if (!err)
+		*tdn = MLX5_GET(alloc_transport_domain_out, out, transport_domain);
+
+	return err;
+}
+
+void mlx5_vdpa_dealloc_transport_domain(struct mlx5_vdpa_dev *mvdev, u32 tdn)
+{
+	u32 in[MLX5_ST_SZ_DW(dealloc_transport_domain_in)] = {};
+
+	MLX5_SET(dealloc_transport_domain_in, in, opcode, MLX5_CMD_OP_DEALLOC_TRANSPORT_DOMAIN);
+	MLX5_SET(dealloc_transport_domain_in, in, uid, mvdev->res.uid);
+	MLX5_SET(dealloc_transport_domain_in, in, transport_domain, tdn);
+	mlx5_cmd_exec_in(mvdev->mdev, dealloc_transport_domain, in);
+}
+
+int mlx5_vdpa_create_mkey(struct mlx5_vdpa_dev *mvdev, struct mlx5_core_mkey *mkey, u32 *in,
+			  int inlen)
+{
+	u32 lout[MLX5_ST_SZ_DW(create_mkey_out)] = {};
+	u32 mkey_index;
+	void *mkc;
+	int err;
+
+	MLX5_SET(create_mkey_in, in, opcode, MLX5_CMD_OP_CREATE_MKEY);
+	MLX5_SET(create_mkey_in, in, uid, mvdev->res.uid);
+
+	err = mlx5_cmd_exec(mvdev->mdev, in, inlen, lout, sizeof(lout));
+	if (err)
+		return err;
+
+	mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry);
+	mkey_index = MLX5_GET(create_mkey_out, lout, mkey_index);
+	mkey->iova = MLX5_GET64(mkc, mkc, start_addr);
+	mkey->size = MLX5_GET64(mkc, mkc, len);
+	mkey->key |= mlx5_idx_to_mkey(mkey_index);
+	mkey->pd = MLX5_GET(mkc, mkc, pd);
+	return 0;
+}
+
+int mlx5_vdpa_destroy_mkey(struct mlx5_vdpa_dev *mvdev, struct mlx5_core_mkey *mkey)
+{
+	u32 in[MLX5_ST_SZ_DW(destroy_mkey_in)] = {};
+
+	MLX5_SET(destroy_mkey_in, in, uid, mvdev->res.uid);
+	MLX5_SET(destroy_mkey_in, in, opcode, MLX5_CMD_OP_DESTROY_MKEY);
+	MLX5_SET(destroy_mkey_in, in, mkey_index, mlx5_mkey_to_idx(mkey->key));
+	return mlx5_cmd_exec_in(mvdev->mdev, destroy_mkey, in);
+}
+
+int mlx5_vdpa_alloc_resources(struct mlx5_vdpa_dev *mvdev)
+{
+	u64 offset = MLX5_CAP64_DEV_VDPA_EMULATION(mvdev->mdev, doorbell_bar_offset);
+	struct mlx5_vdpa_resources *res = &mvdev->res;
+	struct mlx5_core_dev *mdev = mvdev->mdev;
+	u64 kick_addr;
+	int err;
+
+	if (res->valid) {
+		mlx5_vdpa_warn(mvdev, "resources already allocated\n");
+		return -EINVAL;
+	}
+	res->uar = mlx5_get_uars_page(mdev);
+	if (IS_ERR(res->uar)) {
+		err = PTR_ERR(res->uar);
+		goto err_uars;
+	}
+
+	err = create_uctx(mvdev, &res->uid);
+	if (err)
+		goto err_uctx;
+
+	err = alloc_pd(mvdev, &res->pdn, res->uid);
+	if (err)
+		goto err_pd;
+
+	err = get_null_mkey(mvdev, &res->null_mkey);
+	if (err)
+		goto err_key;
+
+	kick_addr = pci_resource_start(mdev->pdev, 0) + offset;
+	res->kick_addr = ioremap(kick_addr, PAGE_SIZE);
+	if (!res->kick_addr) {
+		err = -ENOMEM;
+		goto err_key;
+	}
+	res->valid = true;
+
+	return 0;
+
+err_key:
+	dealloc_pd(mvdev, res->pdn, res->uid);
+err_pd:
+	destroy_uctx(mvdev, res->uid);
+err_uctx:
+	mlx5_put_uars_page(mdev, res->uar);
+err_uars:
+	return err;
+}
+
+void mlx5_vdpa_free_resources(struct mlx5_vdpa_dev *mvdev)
+{
+	struct mlx5_vdpa_resources *res = &mvdev->res;
+
+	if (!res->valid)
+		return;
+
+	iounmap(res->kick_addr);
+	res->kick_addr = NULL;
+	dealloc_pd(mvdev, res->pdn, res->uid);
+	destroy_uctx(mvdev, res->uid);
+	mlx5_put_uars_page(mvdev->mdev, res->uar);
+	res->valid = false;
+}