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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 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/scmi_protocol.h>
18#include <linux/types.h>
19
20#include <asm/unaligned.h>
21
22#define PROTOCOL_REV_MINOR_MASK GENMASK(15, 0)
23#define PROTOCOL_REV_MAJOR_MASK GENMASK(31, 16)
24#define PROTOCOL_REV_MAJOR(x) (u16)(FIELD_GET(PROTOCOL_REV_MAJOR_MASK, (x)))
25#define PROTOCOL_REV_MINOR(x) (u16)(FIELD_GET(PROTOCOL_REV_MINOR_MASK, (x)))
26#define MAX_PROTOCOLS_IMP 16
27#define MAX_OPPS 16
28
29enum scmi_common_cmd {
30 PROTOCOL_VERSION = 0x0,
31 PROTOCOL_ATTRIBUTES = 0x1,
32 PROTOCOL_MESSAGE_ATTRIBUTES = 0x2,
33};
34
35/**
36 * struct scmi_msg_resp_prot_version - Response for a message
37 *
38 * @minor_version: Minor version of the ABI that firmware supports
39 * @major_version: Major version of the ABI that firmware supports
40 *
41 * In general, ABI version changes follow the rule that minor version increments
42 * are backward compatible. Major revision changes in ABI may not be
43 * backward compatible.
44 *
45 * Response to a generic message with message type SCMI_MSG_VERSION
46 */
47struct scmi_msg_resp_prot_version {
48 __le16 minor_version;
49 __le16 major_version;
50};
51
52#define MSG_ID_MASK GENMASK(7, 0)
53#define MSG_XTRACT_ID(hdr) FIELD_GET(MSG_ID_MASK, (hdr))
54#define MSG_TYPE_MASK GENMASK(9, 8)
55#define MSG_XTRACT_TYPE(hdr) FIELD_GET(MSG_TYPE_MASK, (hdr))
56#define MSG_TYPE_COMMAND 0
57#define MSG_TYPE_DELAYED_RESP 2
58#define MSG_TYPE_NOTIFICATION 3
59#define MSG_PROTOCOL_ID_MASK GENMASK(17, 10)
60#define MSG_XTRACT_PROT_ID(hdr) FIELD_GET(MSG_PROTOCOL_ID_MASK, (hdr))
61#define MSG_TOKEN_ID_MASK GENMASK(27, 18)
62#define MSG_XTRACT_TOKEN(hdr) FIELD_GET(MSG_TOKEN_ID_MASK, (hdr))
63#define MSG_TOKEN_MAX (MSG_XTRACT_TOKEN(MSG_TOKEN_ID_MASK) + 1)
64
65/**
66 * struct scmi_msg_hdr - Message(Tx/Rx) header
67 *
68 * @id: The identifier of the message being sent
69 * @protocol_id: The identifier of the protocol used to send @id message
70 * @seq: The token to identify the message. When a message returns, the
71 * platform returns the whole message header unmodified including the
72 * token
73 * @status: Status of the transfer once it's complete
74 * @poll_completion: Indicate if the transfer needs to be polled for
75 * completion or interrupt mode is used
76 */
77struct scmi_msg_hdr {
78 u8 id;
79 u8 protocol_id;
80 u16 seq;
81 u32 status;
82 bool poll_completion;
83};
84
85/**
86 * pack_scmi_header() - packs and returns 32-bit header
87 *
88 * @hdr: pointer to header containing all the information on message id,
89 * protocol id and sequence id.
90 *
91 * Return: 32-bit packed message header to be sent to the platform.
92 */
93static inline u32 pack_scmi_header(struct scmi_msg_hdr *hdr)
94{
95 return FIELD_PREP(MSG_ID_MASK, hdr->id) |
96 FIELD_PREP(MSG_TOKEN_ID_MASK, hdr->seq) |
97 FIELD_PREP(MSG_PROTOCOL_ID_MASK, hdr->protocol_id);
98}
99
100/**
101 * unpack_scmi_header() - unpacks and records message and protocol id
102 *
103 * @msg_hdr: 32-bit packed message header sent from the platform
104 * @hdr: pointer to header to fetch message and protocol id.
105 */
106static inline void unpack_scmi_header(u32 msg_hdr, struct scmi_msg_hdr *hdr)
107{
108 hdr->id = MSG_XTRACT_ID(msg_hdr);
109 hdr->protocol_id = MSG_XTRACT_PROT_ID(msg_hdr);
110}
111
112/**
113 * struct scmi_msg - Message(Tx/Rx) structure
114 *
115 * @buf: Buffer pointer
116 * @len: Length of data in the Buffer
117 */
118struct scmi_msg {
119 void *buf;
120 size_t len;
121};
122
123/**
124 * struct scmi_xfer - Structure representing a message flow
125 *
126 * @transfer_id: Unique ID for debug & profiling purpose
127 * @hdr: Transmit message header
128 * @tx: Transmit message
129 * @rx: Receive message, the buffer should be pre-allocated to store
130 * message. If request-ACK protocol is used, we can reuse the same
131 * buffer for the rx path as we use for the tx path.
132 * @done: command message transmit completion event
133 * @async_done: pointer to delayed response message received event completion
134 */
135struct scmi_xfer {
136 int transfer_id;
137 struct scmi_msg_hdr hdr;
138 struct scmi_msg tx;
139 struct scmi_msg rx;
140 struct completion done;
141 struct completion *async_done;
142};
143
144void scmi_xfer_put(const struct scmi_handle *h, struct scmi_xfer *xfer);
145int scmi_do_xfer(const struct scmi_handle *h, struct scmi_xfer *xfer);
146int scmi_do_xfer_with_response(const struct scmi_handle *h,
147 struct scmi_xfer *xfer);
148int scmi_xfer_get_init(const struct scmi_handle *h, u8 msg_id, u8 prot_id,
149 size_t tx_size, size_t rx_size, struct scmi_xfer **p);
150int scmi_handle_put(const struct scmi_handle *handle);
151struct scmi_handle *scmi_handle_get(struct device *dev);
152void scmi_set_handle(struct scmi_device *scmi_dev);
153int scmi_version_get(const struct scmi_handle *h, u8 protocol, u32 *version);
154void scmi_setup_protocol_implemented(const struct scmi_handle *handle,
155 u8 *prot_imp);
156
157int scmi_base_protocol_init(struct scmi_handle *h);
158
159/* SCMI Transport */
160/**
161 * struct scmi_chan_info - Structure representing a SCMI channel information
162 *
163 * @dev: Reference to device in the SCMI hierarchy corresponding to this
164 * channel
165 * @handle: Pointer to SCMI entity handle
166 * @transport_info: Transport layer related information
167 */
168struct scmi_chan_info {
169 struct device *dev;
170 struct scmi_handle *handle;
171 void *transport_info;
172};
173
174/**
175 * struct scmi_transport_ops - Structure representing a SCMI transport ops
176 *
177 * @chan_available: Callback to check if channel is available or not
178 * @chan_setup: Callback to allocate and setup a channel
179 * @chan_free: Callback to free a channel
180 * @send_message: Callback to send a message
181 * @mark_txdone: Callback to mark tx as done
182 * @fetch_response: Callback to fetch response
183 * @fetch_notification: Callback to fetch notification
184 * @clear_channel: Callback to clear a channel
185 * @poll_done: Callback to poll transfer status
186 */
187struct scmi_transport_ops {
188 bool (*chan_available)(struct device *dev, int idx);
189 int (*chan_setup)(struct scmi_chan_info *cinfo, struct device *dev,
190 bool tx);
191 int (*chan_free)(int id, void *p, void *data);
192 int (*send_message)(struct scmi_chan_info *cinfo,
193 struct scmi_xfer *xfer);
194 void (*mark_txdone)(struct scmi_chan_info *cinfo, int ret);
195 void (*fetch_response)(struct scmi_chan_info *cinfo,
196 struct scmi_xfer *xfer);
197 void (*fetch_notification)(struct scmi_chan_info *cinfo,
198 size_t max_len, struct scmi_xfer *xfer);
199 void (*clear_channel)(struct scmi_chan_info *cinfo);
200 bool (*poll_done)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer);
201};
202
203/**
204 * struct scmi_desc - Description of SoC integration
205 *
206 * @ops: Pointer to the transport specific ops structure
207 * @max_rx_timeout_ms: Timeout for communication with SoC (in Milliseconds)
208 * @max_msg: Maximum number of messages that can be pending
209 * simultaneously in the system
210 * @max_msg_size: Maximum size of data per message that can be handled.
211 */
212struct scmi_desc {
213 struct scmi_transport_ops *ops;
214 int max_rx_timeout_ms;
215 int max_msg;
216 int max_msg_size;
217};
218
219extern const struct scmi_desc scmi_mailbox_desc;
220#ifdef CONFIG_HAVE_ARM_SMCCC
221extern const struct scmi_desc scmi_smc_desc;
222#endif
223
224void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr);
225void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id);
226
227/* shmem related declarations */
228struct scmi_shared_mem;
229
230void shmem_tx_prepare(struct scmi_shared_mem __iomem *shmem,
231 struct scmi_xfer *xfer);
232u32 shmem_read_header(struct scmi_shared_mem __iomem *shmem);
233void shmem_fetch_response(struct scmi_shared_mem __iomem *shmem,
234 struct scmi_xfer *xfer);
235void shmem_fetch_notification(struct scmi_shared_mem __iomem *shmem,
236 size_t max_len, struct scmi_xfer *xfer);
237void shmem_clear_channel(struct scmi_shared_mem __iomem *shmem);
238bool shmem_poll_done(struct scmi_shared_mem __iomem *shmem,
239 struct scmi_xfer *xfer);
240
241#endif /* _SCMI_COMMON_H */
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 */
61static 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 */
75static 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
97struct scmi_revision_info *
98scmi_revision_area_get(const struct scmi_protocol_handle *ph);
99int scmi_handle_put(const struct scmi_handle *handle);
100void scmi_device_link_add(struct device *consumer, struct device *supplier);
101struct scmi_handle *scmi_handle_get(struct device *dev);
102void scmi_set_handle(struct scmi_device *scmi_dev);
103void scmi_setup_protocol_implemented(const struct scmi_protocol_handle *ph,
104 u8 *prot_imp);
105
106int __init scmi_bus_init(void);
107void __exit scmi_bus_exit(void);
108
109const struct scmi_protocol *scmi_protocol_get(int protocol_id);
110void scmi_protocol_put(int protocol_id);
111
112int scmi_protocol_acquire(const struct scmi_handle *handle, u8 protocol_id);
113void 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 */
129struct 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 */
154struct 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
173int scmi_protocol_device_request(const struct scmi_device_id *id_table);
174void scmi_protocol_device_unrequest(const struct scmi_device_id *id_table);
175struct 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 */
206struct 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
219extern const struct scmi_desc scmi_mailbox_desc;
220#endif
221#ifdef CONFIG_ARM_SCMI_TRANSPORT_SMC
222extern const struct scmi_desc scmi_smc_desc;
223#endif
224#ifdef CONFIG_ARM_SCMI_TRANSPORT_VIRTIO
225extern const struct scmi_desc scmi_virtio_desc;
226#endif
227#ifdef CONFIG_ARM_SCMI_TRANSPORT_OPTEE
228extern const struct scmi_desc scmi_optee_desc;
229#endif
230
231void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv);
232void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id);
233
234/* shmem related declarations */
235struct scmi_shared_mem;
236
237void shmem_tx_prepare(struct scmi_shared_mem __iomem *shmem,
238 struct scmi_xfer *xfer, struct scmi_chan_info *cinfo);
239u32 shmem_read_header(struct scmi_shared_mem __iomem *shmem);
240void shmem_fetch_response(struct scmi_shared_mem __iomem *shmem,
241 struct scmi_xfer *xfer);
242void shmem_fetch_notification(struct scmi_shared_mem __iomem *shmem,
243 size_t max_len, struct scmi_xfer *xfer);
244void shmem_clear_channel(struct scmi_shared_mem __iomem *shmem);
245bool shmem_poll_done(struct scmi_shared_mem __iomem *shmem,
246 struct scmi_xfer *xfer);
247
248/* declarations for message passing transports */
249struct scmi_msg_payld;
250
251/* Maximum overhead of message w.r.t. struct scmi_desc.max_msg_size */
252#define SCMI_MSG_MAX_PROT_OVERHEAD (2 * sizeof(__le32))
253
254size_t msg_response_size(struct scmi_xfer *xfer);
255size_t msg_command_size(struct scmi_xfer *xfer);
256void msg_tx_prepare(struct scmi_msg_payld *msg, struct scmi_xfer *xfer);
257u32 msg_read_header(struct scmi_msg_payld *msg);
258void msg_fetch_response(struct scmi_msg_payld *msg, size_t len,
259 struct scmi_xfer *xfer);
260void msg_fetch_notification(struct scmi_msg_payld *msg, size_t len,
261 size_t max_len, struct scmi_xfer *xfer);
262
263void scmi_notification_instance_data_set(const struct scmi_handle *handle,
264 void *priv);
265void *scmi_notification_instance_data_get(const struct scmi_handle *handle);
266#endif /* _SCMI_COMMON_H */