1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * System Control and Management Interface (SCMI) Message Protocol
4 * driver common header file containing some definitions, structures
5 * and function prototypes used in all the different SCMI protocols.
6 *
7 * Copyright (C) 2018-2022 ARM Ltd.
8 */
9 #ifndef _SCMI_COMMON_H
10 #define _SCMI_COMMON_H
11
12 #include <linux/bitfield.h>
13 #include <linux/completion.h>
14 #include <linux/device.h>
15 #include <linux/errno.h>
16 #include <linux/kernel.h>
17 #include <linux/hashtable.h>
18 #include <linux/list.h>
19 #include <linux/module.h>
20 #include <linux/refcount.h>
21 #include <linux/scmi_protocol.h>
22 #include <linux/spinlock.h>
23 #include <linux/types.h>
24
25 #include <asm/unaligned.h>
26
27 #include "protocols.h"
28 #include "notify.h"
29
30 #define SCMI_MAX_CHANNELS 256
31
32 #define SCMI_MAX_RESPONSE_TIMEOUT (2 * MSEC_PER_SEC)
33
34 enum scmi_error_codes {
35 SCMI_SUCCESS = 0, /* Success */
36 SCMI_ERR_SUPPORT = -1, /* Not supported */
37 SCMI_ERR_PARAMS = -2, /* Invalid Parameters */
38 SCMI_ERR_ACCESS = -3, /* Invalid access/permission denied */
39 SCMI_ERR_ENTRY = -4, /* Not found */
40 SCMI_ERR_RANGE = -5, /* Value out of range */
41 SCMI_ERR_BUSY = -6, /* Device busy */
42 SCMI_ERR_COMMS = -7, /* Communication Error */
43 SCMI_ERR_GENERIC = -8, /* Generic Error */
44 SCMI_ERR_HARDWARE = -9, /* Hardware Error */
45 SCMI_ERR_PROTOCOL = -10,/* Protocol Error */
46 };
47
48 static const int scmi_linux_errmap[] = {
49 /* better than switch case as long as return value is continuous */
50 0, /* SCMI_SUCCESS */
51 -EOPNOTSUPP, /* SCMI_ERR_SUPPORT */
52 -EINVAL, /* SCMI_ERR_PARAM */
53 -EACCES, /* SCMI_ERR_ACCESS */
54 -ENOENT, /* SCMI_ERR_ENTRY */
55 -ERANGE, /* SCMI_ERR_RANGE */
56 -EBUSY, /* SCMI_ERR_BUSY */
57 -ECOMM, /* SCMI_ERR_COMMS */
58 -EIO, /* SCMI_ERR_GENERIC */
59 -EREMOTEIO, /* SCMI_ERR_HARDWARE */
60 -EPROTO, /* SCMI_ERR_PROTOCOL */
61 };
62
scmi_to_linux_errno(int errno)63 static inline int scmi_to_linux_errno(int errno)
64 {
65 int err_idx = -errno;
66
67 if (err_idx >= SCMI_SUCCESS && err_idx < ARRAY_SIZE(scmi_linux_errmap))
68 return scmi_linux_errmap[err_idx];
69 return -EIO;
70 }
71
72 #define MSG_ID_MASK GENMASK(7, 0)
73 #define MSG_XTRACT_ID(hdr) FIELD_GET(MSG_ID_MASK, (hdr))
74 #define MSG_TYPE_MASK GENMASK(9, 8)
75 #define MSG_XTRACT_TYPE(hdr) FIELD_GET(MSG_TYPE_MASK, (hdr))
76 #define MSG_TYPE_COMMAND 0
77 #define MSG_TYPE_DELAYED_RESP 2
78 #define MSG_TYPE_NOTIFICATION 3
79 #define MSG_PROTOCOL_ID_MASK GENMASK(17, 10)
80 #define MSG_XTRACT_PROT_ID(hdr) FIELD_GET(MSG_PROTOCOL_ID_MASK, (hdr))
81 #define MSG_TOKEN_ID_MASK GENMASK(27, 18)
82 #define MSG_XTRACT_TOKEN(hdr) FIELD_GET(MSG_TOKEN_ID_MASK, (hdr))
83 #define MSG_TOKEN_MAX (MSG_XTRACT_TOKEN(MSG_TOKEN_ID_MASK) + 1)
84
85 /*
86 * Size of @pending_xfers hashtable included in @scmi_xfers_info; ideally, in
87 * order to minimize space and collisions, this should equal max_msg, i.e. the
88 * maximum number of in-flight messages on a specific platform, but such value
89 * is only available at runtime while kernel hashtables are statically sized:
90 * pick instead as a fixed static size the maximum number of entries that can
91 * fit the whole table into one 4k page.
92 */
93 #define SCMI_PENDING_XFERS_HT_ORDER_SZ 9
94
95 /**
96 * pack_scmi_header() - packs and returns 32-bit header
97 *
98 * @hdr: pointer to header containing all the information on message id,
99 * protocol id, sequence id and type.
100 *
101 * Return: 32-bit packed message header to be sent to the platform.
102 */
pack_scmi_header(struct scmi_msg_hdr * hdr)103 static inline u32 pack_scmi_header(struct scmi_msg_hdr *hdr)
104 {
105 return FIELD_PREP(MSG_ID_MASK, hdr->id) |
106 FIELD_PREP(MSG_TYPE_MASK, hdr->type) |
107 FIELD_PREP(MSG_TOKEN_ID_MASK, hdr->seq) |
108 FIELD_PREP(MSG_PROTOCOL_ID_MASK, hdr->protocol_id);
109 }
110
111 /**
112 * unpack_scmi_header() - unpacks and records message and protocol id
113 *
114 * @msg_hdr: 32-bit packed message header sent from the platform
115 * @hdr: pointer to header to fetch message and protocol id.
116 */
unpack_scmi_header(u32 msg_hdr,struct scmi_msg_hdr * hdr)117 static inline void unpack_scmi_header(u32 msg_hdr, struct scmi_msg_hdr *hdr)
118 {
119 hdr->id = MSG_XTRACT_ID(msg_hdr);
120 hdr->protocol_id = MSG_XTRACT_PROT_ID(msg_hdr);
121 hdr->type = MSG_XTRACT_TYPE(msg_hdr);
122 }
123
124 /*
125 * An helper macro to lookup an xfer from the @pending_xfers hashtable
126 * using the message sequence number token as a key.
127 */
128 #define XFER_FIND(__ht, __k) \
129 ({ \
130 typeof(__k) k_ = __k; \
131 struct scmi_xfer *xfer_ = NULL; \
132 \
133 hash_for_each_possible((__ht), xfer_, node, k_) \
134 if (xfer_->hdr.seq == k_) \
135 break; \
136 xfer_; \
137 })
138
139 struct scmi_revision_info *
140 scmi_revision_area_get(const struct scmi_protocol_handle *ph);
141 void scmi_setup_protocol_implemented(const struct scmi_protocol_handle *ph,
142 u8 *prot_imp);
143
144 extern struct bus_type scmi_bus_type;
145
146 #define SCMI_BUS_NOTIFY_DEVICE_REQUEST 0
147 #define SCMI_BUS_NOTIFY_DEVICE_UNREQUEST 1
148 extern struct blocking_notifier_head scmi_requested_devices_nh;
149
150 struct scmi_device *scmi_device_create(struct device_node *np,
151 struct device *parent, int protocol,
152 const char *name);
153 void scmi_device_destroy(struct device *parent, int protocol, const char *name);
154
155 int scmi_protocol_acquire(const struct scmi_handle *handle, u8 protocol_id);
156 void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id);
157
158 /* SCMI Transport */
159 /**
160 * struct scmi_chan_info - Structure representing a SCMI channel information
161 *
162 * @id: An identifier for this channel: this matches the protocol number
163 * used to initialize this channel
164 * @dev: Reference to device in the SCMI hierarchy corresponding to this
165 * channel
166 * @rx_timeout_ms: The configured RX timeout in milliseconds.
167 * @handle: Pointer to SCMI entity handle
168 * @no_completion_irq: Flag to indicate that this channel has no completion
169 * interrupt mechanism for synchronous commands.
170 * This can be dynamically set by transports at run-time
171 * inside their provided .chan_setup().
172 * @transport_info: Transport layer related information
173 */
174 struct scmi_chan_info {
175 int id;
176 struct device *dev;
177 unsigned int rx_timeout_ms;
178 struct scmi_handle *handle;
179 bool no_completion_irq;
180 void *transport_info;
181 };
182
183 /**
184 * struct scmi_transport_ops - Structure representing a SCMI transport ops
185 *
186 * @link_supplier: Optional callback to add link to a supplier device
187 * @chan_available: Callback to check if channel is available or not
188 * @chan_setup: Callback to allocate and setup a channel
189 * @chan_free: Callback to free a channel
190 * @get_max_msg: Optional callback to provide max_msg dynamically
191 * Returns the maximum number of messages for the channel type
192 * (tx or rx) that can be pending simultaneously in the system
193 * @send_message: Callback to send a message
194 * @mark_txdone: Callback to mark tx as done
195 * @fetch_response: Callback to fetch response
196 * @fetch_notification: Callback to fetch notification
197 * @clear_channel: Callback to clear a channel
198 * @poll_done: Callback to poll transfer status
199 */
200 struct scmi_transport_ops {
201 int (*link_supplier)(struct device *dev);
202 bool (*chan_available)(struct device_node *of_node, int idx);
203 int (*chan_setup)(struct scmi_chan_info *cinfo, struct device *dev,
204 bool tx);
205 int (*chan_free)(int id, void *p, void *data);
206 unsigned int (*get_max_msg)(struct scmi_chan_info *base_cinfo);
207 int (*send_message)(struct scmi_chan_info *cinfo,
208 struct scmi_xfer *xfer);
209 void (*mark_txdone)(struct scmi_chan_info *cinfo, int ret,
210 struct scmi_xfer *xfer);
211 void (*fetch_response)(struct scmi_chan_info *cinfo,
212 struct scmi_xfer *xfer);
213 void (*fetch_notification)(struct scmi_chan_info *cinfo,
214 size_t max_len, struct scmi_xfer *xfer);
215 void (*clear_channel)(struct scmi_chan_info *cinfo);
216 bool (*poll_done)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer);
217 };
218
219 /**
220 * struct scmi_desc - Description of SoC integration
221 *
222 * @transport_init: An optional function that a transport can provide to
223 * initialize some transport-specific setup during SCMI core
224 * initialization, so ahead of SCMI core probing.
225 * @transport_exit: An optional function that a transport can provide to
226 * de-initialize some transport-specific setup during SCMI core
227 * de-initialization, so after SCMI core removal.
228 * @ops: Pointer to the transport specific ops structure
229 * @max_rx_timeout_ms: Timeout for communication with SoC (in Milliseconds)
230 * @max_msg: Maximum number of messages for a channel type (tx or rx) that can
231 * be pending simultaneously in the system. May be overridden by the
232 * get_max_msg op.
233 * @max_msg_size: Maximum size of data per message that can be handled.
234 * @force_polling: Flag to force this whole transport to use SCMI core polling
235 * mechanism instead of completion interrupts even if available.
236 * @sync_cmds_completed_on_ret: Flag to indicate that the transport assures
237 * synchronous-command messages are atomically
238 * completed on .send_message: no need to poll
239 * actively waiting for a response.
240 * Used by core internally only when polling is
241 * selected as a waiting for reply method: i.e.
242 * if a completion irq was found use that anyway.
243 * @atomic_enabled: Flag to indicate that this transport, which is assured not
244 * to sleep anywhere on the TX path, can be used in atomic mode
245 * when requested.
246 */
247 struct scmi_desc {
248 int (*transport_init)(void);
249 void (*transport_exit)(void);
250 const struct scmi_transport_ops *ops;
251 int max_rx_timeout_ms;
252 int max_msg;
253 int max_msg_size;
254 const bool force_polling;
255 const bool sync_cmds_completed_on_ret;
256 const bool atomic_enabled;
257 };
258
is_polling_required(struct scmi_chan_info * cinfo,const struct scmi_desc * desc)259 static inline bool is_polling_required(struct scmi_chan_info *cinfo,
260 const struct scmi_desc *desc)
261 {
262 return cinfo->no_completion_irq || desc->force_polling;
263 }
264
is_transport_polling_capable(const struct scmi_desc * desc)265 static inline bool is_transport_polling_capable(const struct scmi_desc *desc)
266 {
267 return desc->ops->poll_done || desc->sync_cmds_completed_on_ret;
268 }
269
is_polling_enabled(struct scmi_chan_info * cinfo,const struct scmi_desc * desc)270 static inline bool is_polling_enabled(struct scmi_chan_info *cinfo,
271 const struct scmi_desc *desc)
272 {
273 return is_polling_required(cinfo, desc) &&
274 is_transport_polling_capable(desc);
275 }
276
277 void scmi_xfer_raw_put(const struct scmi_handle *handle,
278 struct scmi_xfer *xfer);
279 struct scmi_xfer *scmi_xfer_raw_get(const struct scmi_handle *handle);
280 struct scmi_chan_info *
281 scmi_xfer_raw_channel_get(const struct scmi_handle *handle, u8 protocol_id);
282
283 int scmi_xfer_raw_inflight_register(const struct scmi_handle *handle,
284 struct scmi_xfer *xfer);
285
286 int scmi_xfer_raw_wait_for_message_response(struct scmi_chan_info *cinfo,
287 struct scmi_xfer *xfer,
288 unsigned int timeout_ms);
289 #ifdef CONFIG_ARM_SCMI_TRANSPORT_MAILBOX
290 extern const struct scmi_desc scmi_mailbox_desc;
291 #endif
292 #ifdef CONFIG_ARM_SCMI_TRANSPORT_SMC
293 extern const struct scmi_desc scmi_smc_desc;
294 #endif
295 #ifdef CONFIG_ARM_SCMI_TRANSPORT_VIRTIO
296 extern const struct scmi_desc scmi_virtio_desc;
297 #endif
298 #ifdef CONFIG_ARM_SCMI_TRANSPORT_OPTEE
299 extern const struct scmi_desc scmi_optee_desc;
300 #endif
301
302 void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv);
303
304 /* shmem related declarations */
305 struct scmi_shared_mem;
306
307 void shmem_tx_prepare(struct scmi_shared_mem __iomem *shmem,
308 struct scmi_xfer *xfer, struct scmi_chan_info *cinfo);
309 u32 shmem_read_header(struct scmi_shared_mem __iomem *shmem);
310 void shmem_fetch_response(struct scmi_shared_mem __iomem *shmem,
311 struct scmi_xfer *xfer);
312 void shmem_fetch_notification(struct scmi_shared_mem __iomem *shmem,
313 size_t max_len, struct scmi_xfer *xfer);
314 void shmem_clear_channel(struct scmi_shared_mem __iomem *shmem);
315 bool shmem_poll_done(struct scmi_shared_mem __iomem *shmem,
316 struct scmi_xfer *xfer);
317 bool shmem_channel_free(struct scmi_shared_mem __iomem *shmem);
318
319 /* declarations for message passing transports */
320 struct scmi_msg_payld;
321
322 /* Maximum overhead of message w.r.t. struct scmi_desc.max_msg_size */
323 #define SCMI_MSG_MAX_PROT_OVERHEAD (2 * sizeof(__le32))
324
325 size_t msg_response_size(struct scmi_xfer *xfer);
326 size_t msg_command_size(struct scmi_xfer *xfer);
327 void msg_tx_prepare(struct scmi_msg_payld *msg, struct scmi_xfer *xfer);
328 u32 msg_read_header(struct scmi_msg_payld *msg);
329 void msg_fetch_response(struct scmi_msg_payld *msg, size_t len,
330 struct scmi_xfer *xfer);
331 void msg_fetch_notification(struct scmi_msg_payld *msg, size_t len,
332 size_t max_len, struct scmi_xfer *xfer);
333
334 void scmi_notification_instance_data_set(const struct scmi_handle *handle,
335 void *priv);
336 void *scmi_notification_instance_data_get(const struct scmi_handle *handle);
337 #endif /* _SCMI_COMMON_H */
338