xref: /openbmc/linux/drivers/cdx/controller/mcdi.h (revision eb96b740192b2a09720aaed8a8c132e6a29d5bdb)
1 /* SPDX-License-Identifier: GPL-2.0
2  *
3  * Copyright 2008-2013 Solarflare Communications Inc.
4  * Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
5  */
6 
7 #ifndef CDX_MCDI_H
8 #define CDX_MCDI_H
9 
10 #include <linux/mutex.h>
11 #include <linux/kref.h>
12 
13 #include "bitfield.h"
14 #include "mc_cdx_pcol.h"
15 
16 #ifdef DEBUG
17 #define CDX_WARN_ON_ONCE_PARANOID(x) WARN_ON_ONCE(x)
18 #define CDX_WARN_ON_PARANOID(x) WARN_ON(x)
19 #else
20 #define CDX_WARN_ON_ONCE_PARANOID(x) do {} while (0)
21 #define CDX_WARN_ON_PARANOID(x) do {} while (0)
22 #endif
23 
24 /**
25  * enum cdx_mcdi_mode - MCDI transaction mode
26  * @MCDI_MODE_EVENTS: wait for an mcdi response callback.
27  * @MCDI_MODE_FAIL: we think MCDI is dead, so fail-fast all calls
28  */
29 enum cdx_mcdi_mode {
30 	MCDI_MODE_EVENTS,
31 	MCDI_MODE_FAIL,
32 };
33 
34 #define MCDI_RPC_TIMEOUT	(10 * HZ)
35 #define MCDI_RPC_LONG_TIMEOU	(60 * HZ)
36 #define MCDI_RPC_POST_RST_TIME	(10 * HZ)
37 
38 #define MCDI_BUF_LEN (8 + MCDI_CTL_SDU_LEN_MAX)
39 
40 /**
41  * enum cdx_mcdi_cmd_state - State for an individual MCDI command
42  * @MCDI_STATE_QUEUED: Command not started and is waiting to run.
43  * @MCDI_STATE_RETRY: Command was submitted and MC rejected with no resources,
44  *	as MC have too many outstanding commands. Command will be retried once
45  *	another command returns.
46  * @MCDI_STATE_RUNNING: Command was accepted and is running.
47  * @MCDI_STATE_RUNNING_CANCELLED: Command is running but the issuer cancelled
48  *	the command.
49  * @MCDI_STATE_FINISHED: Processing of this command has completed.
50  */
51 
52 enum cdx_mcdi_cmd_state {
53 	MCDI_STATE_QUEUED,
54 	MCDI_STATE_RETRY,
55 	MCDI_STATE_RUNNING,
56 	MCDI_STATE_RUNNING_CANCELLED,
57 	MCDI_STATE_FINISHED,
58 };
59 
60 /**
61  * struct cdx_mcdi - CDX MCDI Firmware interface, to interact
62  *	with CDX controller.
63  * @mcdi: MCDI interface
64  * @mcdi_ops: MCDI operations
65  */
66 struct cdx_mcdi {
67 	/* MCDI interface */
68 	struct cdx_mcdi_data *mcdi;
69 	const struct cdx_mcdi_ops *mcdi_ops;
70 };
71 
72 struct cdx_mcdi_ops {
73 	void (*mcdi_request)(struct cdx_mcdi *cdx,
74 			     const struct cdx_dword *hdr, size_t hdr_len,
75 			     const struct cdx_dword *sdu, size_t sdu_len);
76 	unsigned int (*mcdi_rpc_timeout)(struct cdx_mcdi *cdx, unsigned int cmd);
77 };
78 
79 typedef void cdx_mcdi_async_completer(struct cdx_mcdi *cdx,
80 				      unsigned long cookie, int rc,
81 				      struct cdx_dword *outbuf,
82 				      size_t outlen_actual);
83 
84 /**
85  * struct cdx_mcdi_cmd - An outstanding MCDI command
86  * @ref: Reference count. There will be one reference if the command is
87  *	in the mcdi_iface cmd_list, another if it's on a cleanup list,
88  *	and a third if it's queued in the work queue.
89  * @list: The data for this entry in mcdi->cmd_list
90  * @cleanup_list: The data for this entry in a cleanup list
91  * @work: The work item for this command, queued in mcdi->workqueue
92  * @mcdi: The mcdi_iface for this command
93  * @state: The state of this command
94  * @inlen: inbuf length
95  * @inbuf: Input buffer
96  * @quiet: Whether to silence errors
97  * @reboot_seen: Whether a reboot has been seen during this command,
98  *	to prevent duplicates
99  * @seq: Sequence number
100  * @started: Jiffies this command was started at
101  * @cookie: Context for completion function
102  * @completer: Completion function
103  * @handle: Command handle
104  * @cmd: Command number
105  * @rc: Return code
106  * @outlen: Length of output buffer
107  * @outbuf: Output buffer
108  */
109 struct cdx_mcdi_cmd {
110 	struct kref ref;
111 	struct list_head list;
112 	struct list_head cleanup_list;
113 	struct work_struct work;
114 	struct cdx_mcdi_iface *mcdi;
115 	enum cdx_mcdi_cmd_state state;
116 	size_t inlen;
117 	const struct cdx_dword *inbuf;
118 	bool quiet;
119 	bool reboot_seen;
120 	u8 seq;
121 	unsigned long started;
122 	unsigned long cookie;
123 	cdx_mcdi_async_completer *completer;
124 	unsigned int handle;
125 	unsigned int cmd;
126 	int rc;
127 	size_t outlen;
128 	struct cdx_dword *outbuf;
129 	/* followed by inbuf data if necessary */
130 };
131 
132 /**
133  * struct cdx_mcdi_iface - MCDI protocol context
134  * @cdx: The associated NIC
135  * @iface_lock: Serialise access to this structure
136  * @outstanding_cleanups: Count of cleanups
137  * @cmd_list: List of outstanding and running commands
138  * @workqueue: Workqueue used for delayed processing
139  * @cmd_complete_wq: Waitqueue for command completion
140  * @db_held_by: Command the MC doorbell is in use by
141  * @seq_held_by: Command each sequence number is in use by
142  * @prev_handle: The last used command handle
143  * @mode: Poll for mcdi completion, or wait for an mcdi_event
144  * @prev_seq: The last used sequence number
145  * @new_epoch: Indicates start of day or start of MC reboot recovery
146  * @logging_buffer: Buffer that may be used to build MCDI tracing messages
147  * @logging_enabled: Whether to trace MCDI
148  */
149 struct cdx_mcdi_iface {
150 	struct cdx_mcdi *cdx;
151 	/* Serialise access */
152 	struct mutex iface_lock;
153 	unsigned int outstanding_cleanups;
154 	struct list_head cmd_list;
155 	struct workqueue_struct *workqueue;
156 	wait_queue_head_t cmd_complete_wq;
157 	struct cdx_mcdi_cmd *db_held_by;
158 	struct cdx_mcdi_cmd *seq_held_by[16];
159 	unsigned int prev_handle;
160 	enum cdx_mcdi_mode mode;
161 	u8 prev_seq;
162 	bool new_epoch;
163 #ifdef CONFIG_MCDI_LOGGING
164 	bool logging_enabled;
165 	char *logging_buffer;
166 #endif
167 };
168 
169 /**
170  * struct cdx_mcdi_data - extra state for NICs that implement MCDI
171  * @iface: Interface/protocol state
172  * @fn_flags: Flags for this function, as returned by %MC_CMD_DRV_ATTACH.
173  */
174 struct cdx_mcdi_data {
175 	struct cdx_mcdi_iface iface;
176 	u32 fn_flags;
177 };
178 
179 static inline struct cdx_mcdi_iface *cdx_mcdi_if(struct cdx_mcdi *cdx)
180 {
181 	return cdx->mcdi ? &cdx->mcdi->iface : NULL;
182 }
183 
184 int cdx_mcdi_init(struct cdx_mcdi *cdx);
185 void cdx_mcdi_finish(struct cdx_mcdi *cdx);
186 
187 void cdx_mcdi_process_cmd(struct cdx_mcdi *cdx, struct cdx_dword *outbuf, int len);
188 int cdx_mcdi_rpc(struct cdx_mcdi *cdx, unsigned int cmd,
189 		 const struct cdx_dword *inbuf, size_t inlen,
190 		 struct cdx_dword *outbuf, size_t outlen, size_t *outlen_actual);
191 int cdx_mcdi_rpc_async(struct cdx_mcdi *cdx, unsigned int cmd,
192 		       const struct cdx_dword *inbuf, size_t inlen,
193 		       cdx_mcdi_async_completer *complete,
194 		       unsigned long cookie);
195 int cdx_mcdi_wait_for_quiescence(struct cdx_mcdi *cdx,
196 				 unsigned int timeout_jiffies);
197 
198 /*
199  * We expect that 16- and 32-bit fields in MCDI requests and responses
200  * are appropriately aligned, but 64-bit fields are only
201  * 32-bit-aligned.
202  */
203 #define MCDI_DECLARE_BUF(_name, _len) struct cdx_dword _name[DIV_ROUND_UP(_len, 4)] = {{0}}
204 #define _MCDI_PTR(_buf, _offset)					\
205 	((u8 *)(_buf) + (_offset))
206 #define MCDI_PTR(_buf, _field)						\
207 	_MCDI_PTR(_buf, MC_CMD_ ## _field ## _OFST)
208 #define _MCDI_CHECK_ALIGN(_ofst, _align)				\
209 	((void)BUILD_BUG_ON_ZERO((_ofst) & ((_align) - 1)),		\
210 	 (_ofst))
211 #define _MCDI_DWORD(_buf, _field)					\
212 	((_buf) + (_MCDI_CHECK_ALIGN(MC_CMD_ ## _field ## _OFST, 4) >> 2))
213 
214 #define MCDI_BYTE(_buf, _field)						\
215 	((void)BUILD_BUG_ON_ZERO(MC_CMD_ ## _field ## _LEN != 1),	\
216 	 *MCDI_PTR(_buf, _field))
217 #define MCDI_WORD(_buf, _field)						\
218 	((void)BUILD_BUG_ON_ZERO(MC_CMD_ ## _field ## _LEN != 2),	\
219 	 le16_to_cpu(*(__force const __le16 *)MCDI_PTR(_buf, _field)))
220 #define MCDI_SET_DWORD(_buf, _field, _value)				\
221 	CDX_POPULATE_DWORD_1(*_MCDI_DWORD(_buf, _field), CDX_DWORD, _value)
222 #define MCDI_DWORD(_buf, _field)					\
223 	CDX_DWORD_FIELD(*_MCDI_DWORD(_buf, _field), CDX_DWORD)
224 #define MCDI_POPULATE_DWORD_1(_buf, _field, _name1, _value1)		\
225 	CDX_POPULATE_DWORD_1(*_MCDI_DWORD(_buf, _field),		\
226 			     MC_CMD_ ## _name1, _value1)
227 #define MCDI_SET_QWORD(_buf, _field, _value)				\
228 	do {								\
229 		CDX_POPULATE_DWORD_1(_MCDI_DWORD(_buf, _field)[0],	\
230 				     CDX_DWORD, (u32)(_value));	\
231 		CDX_POPULATE_DWORD_1(_MCDI_DWORD(_buf, _field)[1],	\
232 				     CDX_DWORD, (u64)(_value) >> 32);	\
233 	} while (0)
234 #define MCDI_QWORD(_buf, _field)					\
235 	(CDX_DWORD_FIELD(_MCDI_DWORD(_buf, _field)[0], CDX_DWORD) |	\
236 	(u64)CDX_DWORD_FIELD(_MCDI_DWORD(_buf, _field)[1], CDX_DWORD) << 32)
237 
238 #endif /* CDX_MCDI_H */
239