1 /*
2  * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *      - Redistributions of source code must retain the above
15  *        copyright notice, this list of conditions and the following
16  *        disclaimer.
17  *
18  *      - Redistributions in binary form must reproduce the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer in the documentation and/or other materials
21  *        provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  *
32  */
33 
34 #ifndef MLX5_FPGA_SDK_H
35 #define MLX5_FPGA_SDK_H
36 
37 #include <linux/types.h>
38 #include <linux/dma-direction.h>
39 
40 /**
41  * DOC: Innova SDK
42  * This header defines the in-kernel API for Innova FPGA client drivers.
43  */
44 #define SBU_QP_QUEUE_SIZE 8
45 #define MLX5_FPGA_CMD_TIMEOUT_MSEC (60 * 1000)
46 
47 /**
48  * enum mlx5_fpga_access_type - Enumerated the different methods possible for
49  * accessing the device memory address space
50  */
51 enum mlx5_fpga_access_type {
52 	/** Use the slow CX-FPGA I2C bus */
53 	MLX5_FPGA_ACCESS_TYPE_I2C = 0x0,
54 	/** Use the fastest available method */
55 	MLX5_FPGA_ACCESS_TYPE_DONTCARE = 0x0,
56 };
57 
58 struct mlx5_fpga_conn;
59 struct mlx5_fpga_device;
60 
61 /**
62  * struct mlx5_fpga_dma_entry - A scatter-gather DMA entry
63  */
64 struct mlx5_fpga_dma_entry {
65 	/** @data: Virtual address pointer to the data */
66 	void *data;
67 	/** @size: Size in bytes of the data */
68 	unsigned int size;
69 	/** @dma_addr: Private member. Physical DMA-mapped address of the data */
70 	dma_addr_t dma_addr;
71 };
72 
73 /**
74  * struct mlx5_fpga_dma_buf - A packet buffer
75  * May contain up to 2 scatter-gather data entries
76  */
77 struct mlx5_fpga_dma_buf {
78 	/** @dma_dir: DMA direction */
79 	enum dma_data_direction dma_dir;
80 	/** @sg: Scatter-gather entries pointing to the data in memory */
81 	struct mlx5_fpga_dma_entry sg[2];
82 	/** @list: Item in SQ backlog, for TX packets */
83 	struct list_head list;
84 	/**
85 	 * @complete: Completion routine, for TX packets
86 	 * @conn: FPGA Connection this packet was sent to
87 	 * @fdev: FPGA device this packet was sent to
88 	 * @buf: The packet buffer
89 	 * @status: 0 if successful, or an error code otherwise
90 	 */
91 	void (*complete)(struct mlx5_fpga_conn *conn,
92 			 struct mlx5_fpga_device *fdev,
93 			 struct mlx5_fpga_dma_buf *buf, u8 status);
94 };
95 
96 /**
97  * struct mlx5_fpga_conn_attr - FPGA connection attributes
98  * Describes the attributes of a connection
99  */
100 struct mlx5_fpga_conn_attr {
101 	/** @tx_size: Size of connection TX queue, in packets */
102 	unsigned int tx_size;
103 	/** @rx_size: Size of connection RX queue, in packets */
104 	unsigned int rx_size;
105 	/**
106 	 * @recv_cb: Callback function which is called for received packets
107 	 * @cb_arg: The value provided in mlx5_fpga_conn_attr.cb_arg
108 	 * @buf: A buffer containing a received packet
109 	 *
110 	 * buf is guaranteed to only contain a single scatter-gather entry.
111 	 * The size of the actual packet received is specified in buf.sg[0].size
112 	 * When this callback returns, the packet buffer may be re-used for
113 	 * subsequent receives.
114 	 */
115 	void (*recv_cb)(void *cb_arg, struct mlx5_fpga_dma_buf *buf);
116 	void *cb_arg;
117 };
118 
119 /**
120  * mlx5_fpga_sbu_conn_create() - Initialize a new FPGA SBU connection
121  * @fdev: The FPGA device
122  * @attr: Attributes of the new connection
123  *
124  * Sets up a new FPGA SBU connection with the specified attributes.
125  * The receive callback function may be called for incoming messages even
126  * before this function returns.
127  *
128  * The caller must eventually destroy the connection by calling
129  * mlx5_fpga_sbu_conn_destroy.
130  *
131  * Return: A new connection, or ERR_PTR() error value otherwise.
132  */
133 struct mlx5_fpga_conn *
134 mlx5_fpga_sbu_conn_create(struct mlx5_fpga_device *fdev,
135 			  struct mlx5_fpga_conn_attr *attr);
136 
137 /**
138  * mlx5_fpga_sbu_conn_destroy() - Destroy an FPGA SBU connection
139  * @conn: The FPGA SBU connection to destroy
140  *
141  * Cleans up an FPGA SBU connection which was previously created with
142  * mlx5_fpga_sbu_conn_create.
143  */
144 void mlx5_fpga_sbu_conn_destroy(struct mlx5_fpga_conn *conn);
145 
146 /**
147  * mlx5_fpga_sbu_conn_sendmsg() - Queue the transmission of a packet
148  * @fdev: An FPGA SBU connection
149  * @buf: The packet buffer
150  *
151  * Queues a packet for transmission over an FPGA SBU connection.
152  * The buffer should not be modified or freed until completion.
153  * Upon completion, the buf's complete() callback is invoked, indicating the
154  * success or error status of the transmission.
155  *
156  * Return: 0 if successful, or an error value otherwise.
157  */
158 int mlx5_fpga_sbu_conn_sendmsg(struct mlx5_fpga_conn *conn,
159 			       struct mlx5_fpga_dma_buf *buf);
160 
161 /**
162  * mlx5_fpga_mem_read() - Read from FPGA memory address space
163  * @fdev: The FPGA device
164  * @size: Size of chunk to read, in bytes
165  * @addr: Starting address to read from, in FPGA address space
166  * @buf: Buffer to read into
167  * @access_type: Method for reading
168  *
169  * Reads from the specified address into the specified buffer.
170  * The address may point to configuration space or to DDR.
171  * Large reads may be performed internally as several non-atomic operations.
172  * This function may sleep, so should not be called from atomic contexts.
173  *
174  * Return: 0 if successful, or an error value otherwise.
175  */
176 int mlx5_fpga_mem_read(struct mlx5_fpga_device *fdev, size_t size, u64 addr,
177 		       void *buf, enum mlx5_fpga_access_type access_type);
178 
179 /**
180  * mlx5_fpga_mem_write() - Write to FPGA memory address space
181  * @fdev: The FPGA device
182  * @size: Size of chunk to write, in bytes
183  * @addr: Starting address to write to, in FPGA address space
184  * @buf: Buffer which contains data to write
185  * @access_type: Method for writing
186  *
187  * Writes the specified buffer data to FPGA memory at the specified address.
188  * The address may point to configuration space or to DDR.
189  * Large writes may be performed internally as several non-atomic operations.
190  * This function may sleep, so should not be called from atomic contexts.
191  *
192  * Return: 0 if successful, or an error value otherwise.
193  */
194 int mlx5_fpga_mem_write(struct mlx5_fpga_device *fdev, size_t size, u64 addr,
195 			void *buf, enum mlx5_fpga_access_type access_type);
196 
197 /**
198  * mlx5_fpga_get_sbu_caps() - Read the SBU capabilities
199  * @fdev: The FPGA device
200  * @size: Size of the buffer to read into
201  * @buf: Buffer to read the capabilities into
202  *
203  * Reads the FPGA SBU capabilities into the specified buffer.
204  * The format of the capabilities buffer is SBU-dependent.
205  *
206  * Return: 0 if successful
207  *         -EINVAL if the buffer is not large enough to contain SBU caps
208  *         or any other error value otherwise.
209  */
210 int mlx5_fpga_get_sbu_caps(struct mlx5_fpga_device *fdev, int size, void *buf);
211 
212 #endif /* MLX5_FPGA_SDK_H */
213