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 */ 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 */ 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 struct scmi_handle *scmi_handle_get(struct device *dev); 101 void scmi_set_handle(struct scmi_device *scmi_dev); 102 void scmi_setup_protocol_implemented(const struct scmi_protocol_handle *ph, 103 u8 *prot_imp); 104 105 int __init scmi_bus_init(void); 106 void __exit scmi_bus_exit(void); 107 108 const struct scmi_protocol *scmi_protocol_get(int protocol_id); 109 void scmi_protocol_put(int protocol_id); 110 111 int scmi_protocol_acquire(const struct scmi_handle *handle, u8 protocol_id); 112 void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id); 113 114 /* SCMI Transport */ 115 /** 116 * struct scmi_chan_info - Structure representing a SCMI channel information 117 * 118 * @dev: Reference to device in the SCMI hierarchy corresponding to this 119 * channel 120 * @handle: Pointer to SCMI entity handle 121 * @no_completion_irq: Flag to indicate that this channel has no completion 122 * interrupt mechanism for synchronous commands. 123 * This can be dynamically set by transports at run-time 124 * inside their provided .chan_setup(). 125 * @transport_info: Transport layer related information 126 */ 127 struct scmi_chan_info { 128 struct device *dev; 129 struct scmi_handle *handle; 130 bool no_completion_irq; 131 void *transport_info; 132 }; 133 134 /** 135 * struct scmi_transport_ops - Structure representing a SCMI transport ops 136 * 137 * @link_supplier: Optional callback to add link to a supplier device 138 * @chan_available: Callback to check if channel is available or not 139 * @chan_setup: Callback to allocate and setup a channel 140 * @chan_free: Callback to free a channel 141 * @get_max_msg: Optional callback to provide max_msg dynamically 142 * Returns the maximum number of messages for the channel type 143 * (tx or rx) that can be pending simultaneously in the system 144 * @send_message: Callback to send a message 145 * @mark_txdone: Callback to mark tx as done 146 * @fetch_response: Callback to fetch response 147 * @fetch_notification: Callback to fetch notification 148 * @clear_channel: Callback to clear a channel 149 * @poll_done: Callback to poll transfer status 150 */ 151 struct scmi_transport_ops { 152 int (*link_supplier)(struct device *dev); 153 bool (*chan_available)(struct device *dev, int idx); 154 int (*chan_setup)(struct scmi_chan_info *cinfo, struct device *dev, 155 bool tx); 156 int (*chan_free)(int id, void *p, void *data); 157 unsigned int (*get_max_msg)(struct scmi_chan_info *base_cinfo); 158 int (*send_message)(struct scmi_chan_info *cinfo, 159 struct scmi_xfer *xfer); 160 void (*mark_txdone)(struct scmi_chan_info *cinfo, int ret, 161 struct scmi_xfer *xfer); 162 void (*fetch_response)(struct scmi_chan_info *cinfo, 163 struct scmi_xfer *xfer); 164 void (*fetch_notification)(struct scmi_chan_info *cinfo, 165 size_t max_len, struct scmi_xfer *xfer); 166 void (*clear_channel)(struct scmi_chan_info *cinfo); 167 bool (*poll_done)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer); 168 }; 169 170 int scmi_protocol_device_request(const struct scmi_device_id *id_table); 171 void scmi_protocol_device_unrequest(const struct scmi_device_id *id_table); 172 struct scmi_device *scmi_child_dev_find(struct device *parent, 173 int prot_id, const char *name); 174 175 /** 176 * struct scmi_desc - Description of SoC integration 177 * 178 * @transport_init: An optional function that a transport can provide to 179 * initialize some transport-specific setup during SCMI core 180 * initialization, so ahead of SCMI core probing. 181 * @transport_exit: An optional function that a transport can provide to 182 * de-initialize some transport-specific setup during SCMI core 183 * de-initialization, so after SCMI core removal. 184 * @ops: Pointer to the transport specific ops structure 185 * @max_rx_timeout_ms: Timeout for communication with SoC (in Milliseconds) 186 * @max_msg: Maximum number of messages for a channel type (tx or rx) that can 187 * be pending simultaneously in the system. May be overridden by the 188 * get_max_msg op. 189 * @max_msg_size: Maximum size of data per message that can be handled. 190 * @force_polling: Flag to force this whole transport to use SCMI core polling 191 * mechanism instead of completion interrupts even if available. 192 * @sync_cmds_completed_on_ret: Flag to indicate that the transport assures 193 * synchronous-command messages are atomically 194 * completed on .send_message: no need to poll 195 * actively waiting for a response. 196 * Used by core internally only when polling is 197 * selected as a waiting for reply method: i.e. 198 * if a completion irq was found use that anyway. 199 * @atomic_enabled: Flag to indicate that this transport, which is assured not 200 * to sleep anywhere on the TX path, can be used in atomic mode 201 * when requested. 202 */ 203 struct scmi_desc { 204 int (*transport_init)(void); 205 void (*transport_exit)(void); 206 const struct scmi_transport_ops *ops; 207 int max_rx_timeout_ms; 208 int max_msg; 209 int max_msg_size; 210 const bool force_polling; 211 const bool sync_cmds_completed_on_ret; 212 const bool atomic_enabled; 213 }; 214 215 #ifdef CONFIG_ARM_SCMI_TRANSPORT_MAILBOX 216 extern const struct scmi_desc scmi_mailbox_desc; 217 #endif 218 #ifdef CONFIG_ARM_SCMI_TRANSPORT_SMC 219 extern const struct scmi_desc scmi_smc_desc; 220 #endif 221 #ifdef CONFIG_ARM_SCMI_TRANSPORT_VIRTIO 222 extern const struct scmi_desc scmi_virtio_desc; 223 #endif 224 #ifdef CONFIG_ARM_SCMI_TRANSPORT_OPTEE 225 extern const struct scmi_desc scmi_optee_desc; 226 #endif 227 228 void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv); 229 void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id); 230 231 /* shmem related declarations */ 232 struct scmi_shared_mem; 233 234 void shmem_tx_prepare(struct scmi_shared_mem __iomem *shmem, 235 struct scmi_xfer *xfer); 236 u32 shmem_read_header(struct scmi_shared_mem __iomem *shmem); 237 void shmem_fetch_response(struct scmi_shared_mem __iomem *shmem, 238 struct scmi_xfer *xfer); 239 void shmem_fetch_notification(struct scmi_shared_mem __iomem *shmem, 240 size_t max_len, struct scmi_xfer *xfer); 241 void shmem_clear_channel(struct scmi_shared_mem __iomem *shmem); 242 bool shmem_poll_done(struct scmi_shared_mem __iomem *shmem, 243 struct scmi_xfer *xfer); 244 245 /* declarations for message passing transports */ 246 struct scmi_msg_payld; 247 248 /* Maximum overhead of message w.r.t. struct scmi_desc.max_msg_size */ 249 #define SCMI_MSG_MAX_PROT_OVERHEAD (2 * sizeof(__le32)) 250 251 size_t msg_response_size(struct scmi_xfer *xfer); 252 size_t msg_command_size(struct scmi_xfer *xfer); 253 void msg_tx_prepare(struct scmi_msg_payld *msg, struct scmi_xfer *xfer); 254 u32 msg_read_header(struct scmi_msg_payld *msg); 255 void msg_fetch_response(struct scmi_msg_payld *msg, size_t len, 256 struct scmi_xfer *xfer); 257 void msg_fetch_notification(struct scmi_msg_payld *msg, size_t len, 258 size_t max_len, struct scmi_xfer *xfer); 259 260 void scmi_notification_instance_data_set(const struct scmi_handle *handle, 261 void *priv); 262 void *scmi_notification_instance_data_get(const struct scmi_handle *handle); 263 #endif /* _SCMI_COMMON_H */ 264