net/mlx5: FPGA, Add SBU infrastructure

Add interface to initialize and interact with Innova FPGA SBU
connections.
A client driver may use these functions to set up a high-speed DMA
connection with its SBU hardware logic, and send/receive messages
over this connection.

A later patch in this patchset will make use of these functions for
Innova IPSec offload in mlx5 Ethernet driver.

Add commands to retrieve Innova FPGA SBU capabilities, and to
read/write Innova FPGA configuration space registers and memory,
over internal I2C.

At high level, the FPGA configuration space is divided such:
 0x00000000 - 0x007fffff is reserved for the SBU
 0x00800000 - 0xffffffff is reserved for the Shell
0x400000000 - ...        is DDR memory

A later patchset will add support for accessing FPGA CrSpace and memory
over a high-speed connection. This is the reason for the ACCESS_TYPE
enumeration, which currently only supports I2C.

Signed-off-by: Ilan Tayari <ilant@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

drivers/net/ethernet/mellanox/mlx5/core/Makefile

@@ -6,7 +6,7 @@ mlx5_core-y :=	main.o cmd.o debugfs.o fw.o eq.o uar.o pagealloc.o \
 		mad.o transobj.o vport.o sriov.o fs_cmd.o fs_core.o \
 		fs_counters.o rl.o lag.o dev.o lib/gid.o
 
-mlx5_core-$(CONFIG_MLX5_FPGA) += fpga/cmd.o fpga/core.o fpga/conn.o
+mlx5_core-$(CONFIG_MLX5_FPGA) += fpga/cmd.o fpga/core.o fpga/conn.o fpga/sdk.o
 
 mlx5_core-$(CONFIG_MLX5_CORE_EN) += wq.o eswitch.o eswitch_offloads.o \
 		en_main.o en_common.o en_fs.o en_ethtool.o en_tx.o \

drivers/net/ethernet/mellanox/mlx5/core/fpga/cmd.c

@@ -38,6 +38,39 @@
 #include "mlx5_core.h"
 #include "fpga/cmd.h"
 
+#define MLX5_FPGA_ACCESS_REG_SZ (MLX5_ST_SZ_DW(fpga_access_reg) + \
+				 MLX5_FPGA_ACCESS_REG_SIZE_MAX)
+
+int mlx5_fpga_access_reg(struct mlx5_core_dev *dev, u8 size, u64 addr,
+			 void *buf, bool write)
+{
+	u32 in[MLX5_FPGA_ACCESS_REG_SZ] = {0};
+	u32 out[MLX5_FPGA_ACCESS_REG_SZ];
+	int err;
+
+	if (size & 3)
+		return -EINVAL;
+	if (addr & 3)
+		return -EINVAL;
+	if (size > MLX5_FPGA_ACCESS_REG_SIZE_MAX)
+		return -EINVAL;
+
+	MLX5_SET(fpga_access_reg, in, size, size);
+	MLX5_SET64(fpga_access_reg, in, address, addr);
+	if (write)
+		memcpy(MLX5_ADDR_OF(fpga_access_reg, in, data), buf, size);
+
+	err = mlx5_core_access_reg(dev, in, sizeof(in), out, sizeof(out),
+				   MLX5_REG_FPGA_ACCESS_REG, 0, write);
+	if (err)
+		return err;
+
+	if (!write)
+		memcpy(buf, MLX5_ADDR_OF(fpga_access_reg, out, data), size);
+
+	return 0;
+}
+
 int mlx5_fpga_caps(struct mlx5_core_dev *dev, u32 *caps)
 {
 	u32 in[MLX5_ST_SZ_DW(fpga_cap)] = {0};
@@ -58,6 +91,38 @@ int mlx5_fpga_ctrl_op(struct mlx5_core_dev *dev, u8 op)
 				    MLX5_REG_FPGA_CTRL, 0, true);
 }
 
+int mlx5_fpga_sbu_caps(struct mlx5_core_dev *dev, void *caps, int size)
+{
+	unsigned int cap_size = MLX5_CAP_FPGA(dev, sandbox_extended_caps_len);
+	u64 addr = MLX5_CAP64_FPGA(dev, sandbox_extended_caps_addr);
+	unsigned int read;
+	int ret = 0;
+
+	if (cap_size > size) {
+		mlx5_core_warn(dev, "Not enough buffer %u for FPGA SBU caps %u",
+			       size, cap_size);
+		return -EINVAL;
+	}
+
+	while (cap_size > 0) {
+		read = min_t(unsigned int, cap_size,
+			     MLX5_FPGA_ACCESS_REG_SIZE_MAX);
+
+		ret = mlx5_fpga_access_reg(dev, read, addr, caps, false);
+		if (ret) {
+			mlx5_core_warn(dev, "Error reading FPGA SBU caps %u bytes at address 0x%llx: %d",
+				       read, addr, ret);
+			return ret;
+		}
+
+		cap_size -= read;
+		addr += read;
+		caps += read;
+	}
+
+	return ret;
+}
+
 int mlx5_fpga_query(struct mlx5_core_dev *dev, struct mlx5_fpga_query *query)
 {
 	u32 in[MLX5_ST_SZ_DW(fpga_ctrl)] = {0};

drivers/net/ethernet/mellanox/mlx5/core/fpga/cmd.h

@@ -68,6 +68,9 @@ struct mlx5_fpga_qp_counters {
 int mlx5_fpga_caps(struct mlx5_core_dev *dev, u32 *caps);
 int mlx5_fpga_query(struct mlx5_core_dev *dev, struct mlx5_fpga_query *query);
 int mlx5_fpga_ctrl_op(struct mlx5_core_dev *dev, u8 op);
+int mlx5_fpga_access_reg(struct mlx5_core_dev *dev, u8 size, u64 addr,
+			 void *buf, bool write);
+int mlx5_fpga_sbu_caps(struct mlx5_core_dev *dev, void *caps, int size);
 
 int mlx5_fpga_create_qp(struct mlx5_core_dev *dev, void *fpga_qpc,
 			u32 *fpga_qpn);

drivers/net/ethernet/mellanox/mlx5/core/fpga/sdk.c

@@ -0,0 +1,164 @@
+/*
+ * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ */
+
+#include <linux/mlx5/device.h>
+
+#include "fpga/core.h"
+#include "fpga/conn.h"
+#include "fpga/sdk.h"
+
+struct mlx5_fpga_conn *
+mlx5_fpga_sbu_conn_create(struct mlx5_fpga_device *fdev,
+			  struct mlx5_fpga_conn_attr *attr)
+{
+	return mlx5_fpga_conn_create(fdev, attr, MLX5_FPGA_QPC_QP_TYPE_SANDBOX_QP);
+}
+EXPORT_SYMBOL(mlx5_fpga_sbu_conn_create);
+
+void mlx5_fpga_sbu_conn_destroy(struct mlx5_fpga_conn *conn)
+{
+	mlx5_fpga_conn_destroy(conn);
+}
+EXPORT_SYMBOL(mlx5_fpga_sbu_conn_destroy);
+
+int mlx5_fpga_sbu_conn_sendmsg(struct mlx5_fpga_conn *conn,
+			       struct mlx5_fpga_dma_buf *buf)
+{
+	return mlx5_fpga_conn_send(conn, buf);
+}
+EXPORT_SYMBOL(mlx5_fpga_sbu_conn_sendmsg);
+
+static int mlx5_fpga_mem_read_i2c(struct mlx5_fpga_device *fdev, size_t size,
+				  u64 addr, u8 *buf)
+{
+	size_t max_size = MLX5_FPGA_ACCESS_REG_SIZE_MAX;
+	size_t bytes_done = 0;
+	u8 actual_size;
+	int err;
+
+	if (!fdev->mdev)
+		return -ENOTCONN;
+
+	while (bytes_done < size) {
+		actual_size = min(max_size, (size - bytes_done));
+
+		err = mlx5_fpga_access_reg(fdev->mdev, actual_size,
+					   addr + bytes_done,
+					   buf + bytes_done, false);
+		if (err) {
+			mlx5_fpga_err(fdev, "Failed to read over I2C: %d\n",
+				      err);
+			break;
+		}
+
+		bytes_done += actual_size;
+	}
+
+	return err;
+}
+
+static int mlx5_fpga_mem_write_i2c(struct mlx5_fpga_device *fdev, size_t size,
+				   u64 addr, u8 *buf)
+{
+	size_t max_size = MLX5_FPGA_ACCESS_REG_SIZE_MAX;
+	size_t bytes_done = 0;
+	u8 actual_size;
+	int err;
+
+	if (!fdev->mdev)
+		return -ENOTCONN;
+
+	while (bytes_done < size) {
+		actual_size = min(max_size, (size - bytes_done));
+
+		err = mlx5_fpga_access_reg(fdev->mdev, actual_size,
+					   addr + bytes_done,
+					   buf + bytes_done, true);
+		if (err) {
+			mlx5_fpga_err(fdev, "Failed to write FPGA crspace\n");
+			break;
+		}
+
+		bytes_done += actual_size;
+	}
+
+	return err;
+}
+
+int mlx5_fpga_mem_read(struct mlx5_fpga_device *fdev, size_t size, u64 addr,
+		       void *buf, enum mlx5_fpga_access_type access_type)
+{
+	int ret;
+
+	switch (access_type) {
+	case MLX5_FPGA_ACCESS_TYPE_I2C:
+		ret = mlx5_fpga_mem_read_i2c(fdev, size, addr, buf);
+		if (ret)
+			return ret;
+		break;
+	default:
+		mlx5_fpga_warn(fdev, "Unexpected read access_type %u\n",
+			       access_type);
+		return -EACCES;
+	}
+
+	return size;
+}
+EXPORT_SYMBOL(mlx5_fpga_mem_read);
+
+int mlx5_fpga_mem_write(struct mlx5_fpga_device *fdev, size_t size, u64 addr,
+			void *buf, enum mlx5_fpga_access_type access_type)
+{
+	int ret;
+
+	switch (access_type) {
+	case MLX5_FPGA_ACCESS_TYPE_I2C:
+		ret = mlx5_fpga_mem_write_i2c(fdev, size, addr, buf);
+		if (ret)
+			return ret;
+		break;
+	default:
+		mlx5_fpga_warn(fdev, "Unexpected write access_type %u\n",
+			       access_type);
+		return -EACCES;
+	}
+
+	return size;
+}
+EXPORT_SYMBOL(mlx5_fpga_mem_write);
+
+int mlx5_fpga_get_sbu_caps(struct mlx5_fpga_device *fdev, int size, void *buf)
+{
+	return mlx5_fpga_sbu_caps(fdev->mdev, buf, size);
+}
+EXPORT_SYMBOL(mlx5_fpga_get_sbu_caps);

drivers/net/ethernet/mellanox/mlx5/core/fpga/sdk.h

@@ -42,6 +42,11 @@
  * This header defines the in-kernel API for Innova FPGA client drivers.
  */
 
+enum mlx5_fpga_access_type {
+	MLX5_FPGA_ACCESS_TYPE_I2C = 0x0,
+	MLX5_FPGA_ACCESS_TYPE_DONTCARE = 0x0,
+};
+
 struct mlx5_fpga_conn;
 struct mlx5_fpga_device;
 
@@ -103,4 +108,97 @@ struct mlx5_fpga_conn_attr {
 	void *cb_arg;
 };
 
+/**
+ * mlx5_fpga_sbu_conn_create() - Initialize a new FPGA SBU connection
+ * @fdev: The FPGA device
+ * @attr: Attributes of the new connection
+ *
+ * Sets up a new FPGA SBU connection with the specified attributes.
+ * The receive callback function may be called for incoming messages even
+ * before this function returns.
+ *
+ * The caller must eventually destroy the connection by calling
+ * mlx5_fpga_sbu_conn_destroy.
+ *
+ * Return: A new connection, or ERR_PTR() error value otherwise.
+ */
+struct mlx5_fpga_conn *
+mlx5_fpga_sbu_conn_create(struct mlx5_fpga_device *fdev,
+			  struct mlx5_fpga_conn_attr *attr);
+
+/**
+ * mlx5_fpga_sbu_conn_destroy() - Destroy an FPGA SBU connection
+ * @conn: The FPGA SBU connection to destroy
+ *
+ * Cleans up an FPGA SBU connection which was previously created with
+ * mlx5_fpga_sbu_conn_create.
+ */
+void mlx5_fpga_sbu_conn_destroy(struct mlx5_fpga_conn *conn);
+
+/**
+ * mlx5_fpga_sbu_conn_sendmsg() - Queue the transmission of a packet
+ * @fdev: An FPGA SBU connection
+ * @buf: The packet buffer
+ *
+ * Queues a packet for transmission over an FPGA SBU connection.
+ * The buffer should not be modified or freed until completion.
+ * Upon completion, the buf's complete() callback is invoked, indicating the
+ * success or error status of the transmission.
+ *
+ * Return: 0 if successful, or an error value otherwise.
+ */
+int mlx5_fpga_sbu_conn_sendmsg(struct mlx5_fpga_conn *conn,
+			       struct mlx5_fpga_dma_buf *buf);
+
+/**
+ * mlx5_fpga_mem_read() - Read from FPGA memory address space
+ * @fdev: The FPGA device
+ * @size: Size of chunk to read, in bytes
+ * @addr: Starting address to read from, in FPGA address space
+ * @buf: Buffer to read into
+ * @access_type: Method for reading
+ *
+ * Reads from the specified address into the specified buffer.
+ * The address may point to configuration space or to DDR.
+ * Large reads may be performed internally as several non-atomic operations.
+ * This function may sleep, so should not be called from atomic contexts.
+ *
+ * Return: 0 if successful, or an error value otherwise.
+ */
+int mlx5_fpga_mem_read(struct mlx5_fpga_device *fdev, size_t size, u64 addr,
+		       void *buf, enum mlx5_fpga_access_type access_type);
+
+/**
+ * mlx5_fpga_mem_write() - Write to FPGA memory address space
+ * @fdev: The FPGA device
+ * @size: Size of chunk to write, in bytes
+ * @addr: Starting address to write to, in FPGA address space
+ * @buf: Buffer which contains data to write
+ * @access_type: Method for writing
+ *
+ * Writes the specified buffer data to FPGA memory at the specified address.
+ * The address may point to configuration space or to DDR.
+ * Large writes may be performed internally as several non-atomic operations.
+ * This function may sleep, so should not be called from atomic contexts.
+ *
+ * Return: 0 if successful, or an error value otherwise.
+ */
+int mlx5_fpga_mem_write(struct mlx5_fpga_device *fdev, size_t size, u64 addr,
+			void *buf, enum mlx5_fpga_access_type access_type);
+
+/**
+ * mlx5_fpga_get_sbu_caps() - Read the SBU capabilities
+ * @fdev: The FPGA device
+ * @size: Size of the buffer to read into
+ * @buf: Buffer to read the capabilities into
+ *
+ * Reads the FPGA SBU capabilities into the specified buffer.
+ * The format of the capabilities buffer is SBU-dependent.
+ *
+ * Return: 0 if successful
+ *         -EINVAL if the buffer is not large enough to contain SBU caps
+ *         or any other error value otherwise.
+ */
+int mlx5_fpga_get_sbu_caps(struct mlx5_fpga_device *fdev, int size, void *buf);
+
 #endif /* MLX5_FPGA_SDK_H */

include/linux/mlx5/device.h

@@ -1103,6 +1103,9 @@ enum mlx5_mcam_feature_groups {
 #define MLX5_CAP_FPGA(mdev, cap) \
 	MLX5_GET(fpga_cap, (mdev)->caps.hca_cur[MLX5_CAP_FPGA], cap)
 
+#define MLX5_CAP64_FPGA(mdev, cap) \
+	MLX5_GET64(fpga_cap, (mdev)->caps.hca_cur[MLX5_CAP_FPGA], cap)
+
 enum {
 	MLX5_CMD_STAT_OK			= 0x0,
 	MLX5_CMD_STAT_INT_ERR			= 0x1,

include/linux/mlx5/driver.h

@@ -111,6 +111,7 @@ enum {
 	MLX5_REG_DCBX_APP        = 0x4021,
 	MLX5_REG_FPGA_CAP	 = 0x4022,
 	MLX5_REG_FPGA_CTRL	 = 0x4023,
+	MLX5_REG_FPGA_ACCESS_REG = 0x4024,
 	MLX5_REG_PCAP		 = 0x5001,
 	MLX5_REG_PMTU		 = 0x5003,
 	MLX5_REG_PTYS		 = 0x5004,

include/linux/mlx5/mlx5_ifc.h

@@ -8309,6 +8309,7 @@ union mlx5_ifc_ports_control_registers_document_bits {
 	struct mlx5_ifc_sltp_reg_bits sltp_reg;
 	struct mlx5_ifc_mtpps_reg_bits mtpps_reg;
 	struct mlx5_ifc_mtppse_reg_bits mtppse_reg;
+	struct mlx5_ifc_fpga_access_reg_bits fpga_access_reg;
 	struct mlx5_ifc_fpga_ctrl_bits fpga_ctrl_bits;
 	struct mlx5_ifc_fpga_cap_bits fpga_cap_bits;
 	struct mlx5_ifc_mcqi_reg_bits mcqi_reg;