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 MSG_ID_MASK GENMASK(7, 0)
31 #define MSG_XTRACT_ID(hdr) FIELD_GET(MSG_ID_MASK, (hdr))
32 #define MSG_TYPE_MASK GENMASK(9, 8)
33 #define MSG_XTRACT_TYPE(hdr) FIELD_GET(MSG_TYPE_MASK, (hdr))
34 #define MSG_TYPE_COMMAND 0
35 #define MSG_TYPE_DELAYED_RESP 2
36 #define MSG_TYPE_NOTIFICATION 3
37 #define MSG_PROTOCOL_ID_MASK GENMASK(17, 10)
38 #define MSG_XTRACT_PROT_ID(hdr) FIELD_GET(MSG_PROTOCOL_ID_MASK, (hdr))
39 #define MSG_TOKEN_ID_MASK GENMASK(27, 18)
40 #define MSG_XTRACT_TOKEN(hdr) FIELD_GET(MSG_TOKEN_ID_MASK, (hdr))
41 #define MSG_TOKEN_MAX (MSG_XTRACT_TOKEN(MSG_TOKEN_ID_MASK) + 1)
42
43 /*
44 * Size of @pending_xfers hashtable included in @scmi_xfers_info; ideally, in
45 * order to minimize space and collisions, this should equal max_msg, i.e. the
46 * maximum number of in-flight messages on a specific platform, but such value
47 * is only available at runtime while kernel hashtables are statically sized:
48 * pick instead as a fixed static size the maximum number of entries that can
49 * fit the whole table into one 4k page.
50 */
51 #define SCMI_PENDING_XFERS_HT_ORDER_SZ 9
52
53 /**
54 * pack_scmi_header() - packs and returns 32-bit header
55 *
56 * @hdr: pointer to header containing all the information on message id,
57 * protocol id, sequence id and type.
58 *
59 * Return: 32-bit packed message header to be sent to the platform.
60 */
pack_scmi_header(struct scmi_msg_hdr * hdr)61 static inline u32 pack_scmi_header(struct scmi_msg_hdr *hdr)
62 {
63 return FIELD_PREP(MSG_ID_MASK, hdr->id) |
64 FIELD_PREP(MSG_TYPE_MASK, hdr->type) |
65 FIELD_PREP(MSG_TOKEN_ID_MASK, hdr->seq) |
66 FIELD_PREP(MSG_PROTOCOL_ID_MASK, hdr->protocol_id);
67 }
68
69 /**
70 * unpack_scmi_header() - unpacks and records message and protocol id
71 *
72 * @msg_hdr: 32-bit packed message header sent from the platform
73 * @hdr: pointer to header to fetch message and protocol id.
74 */
unpack_scmi_header(u32 msg_hdr,struct scmi_msg_hdr * hdr)75 static inline void unpack_scmi_header(u32 msg_hdr, struct scmi_msg_hdr *hdr)
76 {
77 hdr->id = MSG_XTRACT_ID(msg_hdr);
78 hdr->protocol_id = MSG_XTRACT_PROT_ID(msg_hdr);
79 hdr->type = MSG_XTRACT_TYPE(msg_hdr);
80 }
81
82 /*
83 * An helper macro to lookup an xfer from the @pending_xfers hashtable
84 * using the message sequence number token as a key.
85 */
86 #define XFER_FIND(__ht, __k) \
87 ({ \
88 typeof(__k) k_ = __k; \
89 struct scmi_xfer *xfer_ = NULL; \
90 \
91 hash_for_each_possible((__ht), xfer_, node, k_) \
92 if (xfer_->hdr.seq == k_) \
93 break; \
94 xfer_; \
95 })
96
97 struct scmi_revision_info *
98 scmi_revision_area_get(const struct scmi_protocol_handle *ph);
99 int scmi_handle_put(const struct scmi_handle *handle);
100 void scmi_device_link_add(struct device *consumer, struct device *supplier);
101 struct scmi_handle *scmi_handle_get(struct device *dev);
102 void scmi_set_handle(struct scmi_device *scmi_dev);
103 void scmi_setup_protocol_implemented(const struct scmi_protocol_handle *ph,
104 u8 *prot_imp);
105
106 int __init scmi_bus_init(void);
107 void __exit scmi_bus_exit(void);
108
109 const struct scmi_protocol *scmi_protocol_get(int protocol_id);
110 void scmi_protocol_put(int protocol_id);
111
112 int scmi_protocol_acquire(const struct scmi_handle *handle, u8 protocol_id);
113 void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id);
114
115 /* SCMI Transport */
116 /**
117 * struct scmi_chan_info - Structure representing a SCMI channel information
118 *
119 * @dev: Reference to device in the SCMI hierarchy corresponding to this
120 * channel
121 * @rx_timeout_ms: The configured RX timeout in milliseconds.
122 * @handle: Pointer to SCMI entity handle
123 * @no_completion_irq: Flag to indicate that this channel has no completion
124 * interrupt mechanism for synchronous commands.
125 * This can be dynamically set by transports at run-time
126 * inside their provided .chan_setup().
127 * @transport_info: Transport layer related information
128 */
129 struct scmi_chan_info {
130 struct device *dev;
131 unsigned int rx_timeout_ms;
132 struct scmi_handle *handle;
133 bool no_completion_irq;
134 void *transport_info;
135 };
136
137 /**
138 * struct scmi_transport_ops - Structure representing a SCMI transport ops
139 *
140 * @link_supplier: Optional callback to add link to a supplier device
141 * @chan_available: Callback to check if channel is available or not
142 * @chan_setup: Callback to allocate and setup a channel
143 * @chan_free: Callback to free a channel
144 * @get_max_msg: Optional callback to provide max_msg dynamically
145 * Returns the maximum number of messages for the channel type
146 * (tx or rx) that can be pending simultaneously in the system
147 * @send_message: Callback to send a message
148 * @mark_txdone: Callback to mark tx as done
149 * @fetch_response: Callback to fetch response
150 * @fetch_notification: Callback to fetch notification
151 * @clear_channel: Callback to clear a channel
152 * @poll_done: Callback to poll transfer status
153 */
154 struct scmi_transport_ops {
155 int (*link_supplier)(struct device *dev);
156 bool (*chan_available)(struct device *dev, int idx);
157 int (*chan_setup)(struct scmi_chan_info *cinfo, struct device *dev,
158 bool tx);
159 int (*chan_free)(int id, void *p, void *data);
160 unsigned int (*get_max_msg)(struct scmi_chan_info *base_cinfo);
161 int (*send_message)(struct scmi_chan_info *cinfo,
162 struct scmi_xfer *xfer);
163 void (*mark_txdone)(struct scmi_chan_info *cinfo, int ret,
164 struct scmi_xfer *xfer);
165 void (*fetch_response)(struct scmi_chan_info *cinfo,
166 struct scmi_xfer *xfer);
167 void (*fetch_notification)(struct scmi_chan_info *cinfo,
168 size_t max_len, struct scmi_xfer *xfer);
169 void (*clear_channel)(struct scmi_chan_info *cinfo);
170 bool (*poll_done)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer);
171 };
172
173 int scmi_protocol_device_request(const struct scmi_device_id *id_table);
174 void scmi_protocol_device_unrequest(const struct scmi_device_id *id_table);
175 struct scmi_device *scmi_child_dev_find(struct device *parent,
176 int prot_id, const char *name);
177
178 /**
179 * struct scmi_desc - Description of SoC integration
180 *
181 * @transport_init: An optional function that a transport can provide to
182 * initialize some transport-specific setup during SCMI core
183 * initialization, so ahead of SCMI core probing.
184 * @transport_exit: An optional function that a transport can provide to
185 * de-initialize some transport-specific setup during SCMI core
186 * de-initialization, so after SCMI core removal.
187 * @ops: Pointer to the transport specific ops structure
188 * @max_rx_timeout_ms: Timeout for communication with SoC (in Milliseconds)
189 * @max_msg: Maximum number of messages for a channel type (tx or rx) that can
190 * be pending simultaneously in the system. May be overridden by the
191 * get_max_msg op.
192 * @max_msg_size: Maximum size of data per message that can be handled.
193 * @force_polling: Flag to force this whole transport to use SCMI core polling
194 * mechanism instead of completion interrupts even if available.
195 * @sync_cmds_completed_on_ret: Flag to indicate that the transport assures
196 * synchronous-command messages are atomically
197 * completed on .send_message: no need to poll
198 * actively waiting for a response.
199 * Used by core internally only when polling is
200 * selected as a waiting for reply method: i.e.
201 * if a completion irq was found use that anyway.
202 * @atomic_enabled: Flag to indicate that this transport, which is assured not
203 * to sleep anywhere on the TX path, can be used in atomic mode
204 * when requested.
205 */
206 struct scmi_desc {
207 int (*transport_init)(void);
208 void (*transport_exit)(void);
209 const struct scmi_transport_ops *ops;
210 int max_rx_timeout_ms;
211 int max_msg;
212 int max_msg_size;
213 const bool force_polling;
214 const bool sync_cmds_completed_on_ret;
215 const bool atomic_enabled;
216 };
217
218 #ifdef CONFIG_ARM_SCMI_TRANSPORT_MAILBOX
219 extern const struct scmi_desc scmi_mailbox_desc;
220 #endif
221 #ifdef CONFIG_ARM_SCMI_TRANSPORT_SMC
222 extern const struct scmi_desc scmi_smc_desc;
223 #endif
224 #ifdef CONFIG_ARM_SCMI_TRANSPORT_VIRTIO
225 extern const struct scmi_desc scmi_virtio_desc;
226 #endif
227 #ifdef CONFIG_ARM_SCMI_TRANSPORT_OPTEE
228 extern const struct scmi_desc scmi_optee_desc;
229 #endif
230
231 void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv);
232 void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id);
233
234 /* shmem related declarations */
235 struct scmi_shared_mem;
236
237 void shmem_tx_prepare(struct scmi_shared_mem __iomem *shmem,
238 struct scmi_xfer *xfer, struct scmi_chan_info *cinfo);
239 u32 shmem_read_header(struct scmi_shared_mem __iomem *shmem);
240 void shmem_fetch_response(struct scmi_shared_mem __iomem *shmem,
241 struct scmi_xfer *xfer);
242 void shmem_fetch_notification(struct scmi_shared_mem __iomem *shmem,
243 size_t max_len, struct scmi_xfer *xfer);
244 void shmem_clear_channel(struct scmi_shared_mem __iomem *shmem);
245 bool shmem_poll_done(struct scmi_shared_mem __iomem *shmem,
246 struct scmi_xfer *xfer);
247 bool shmem_channel_free(struct scmi_shared_mem __iomem *shmem);
248
249 /* declarations for message passing transports */
250 struct scmi_msg_payld;
251
252 /* Maximum overhead of message w.r.t. struct scmi_desc.max_msg_size */
253 #define SCMI_MSG_MAX_PROT_OVERHEAD (2 * sizeof(__le32))
254
255 size_t msg_response_size(struct scmi_xfer *xfer);
256 size_t msg_command_size(struct scmi_xfer *xfer);
257 void msg_tx_prepare(struct scmi_msg_payld *msg, struct scmi_xfer *xfer);
258 u32 msg_read_header(struct scmi_msg_payld *msg);
259 void msg_fetch_response(struct scmi_msg_payld *msg, size_t len,
260 struct scmi_xfer *xfer);
261 void msg_fetch_notification(struct scmi_msg_payld *msg, size_t len,
262 size_t max_len, struct scmi_xfer *xfer);
263
264 void scmi_notification_instance_data_set(const struct scmi_handle *handle,
265 void *priv);
266 void *scmi_notification_instance_data_get(const struct scmi_handle *handle);
267 #endif /* _SCMI_COMMON_H */
268