drivers/firmware/arm_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) 2018-2024 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
  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  */
 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  */
 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 const 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  * @chan_available: Callback to check if channel is available or not
 187  * @chan_setup: Callback to allocate and setup a channel
 188  * @chan_free: Callback to free a channel
 189  * @get_max_msg: Optional callback to provide max_msg dynamically
 190  *               Returns the maximum number of messages for the channel type
 191  *               (tx or rx) that can be pending simultaneously in the system
 192  * @send_message: Callback to send a message
 193  * @mark_txdone: Callback to mark tx as done
 194  * @fetch_response: Callback to fetch response
 195  * @fetch_notification: Callback to fetch notification
 196  * @clear_channel: Callback to clear a channel
 197  * @poll_done: Callback to poll transfer status
 198  */
 199 struct scmi_transport_ops {
 200         bool (*chan_available)(struct device_node *of_node, int idx);
 201         int (*chan_setup)(struct scmi_chan_info *cinfo, struct device *dev,
 202                           bool tx);
 203         int (*chan_free)(int id, void *p, void *data);
 204         unsigned int (*get_max_msg)(struct scmi_chan_info *base_cinfo);
 205         int (*send_message)(struct scmi_chan_info *cinfo,
 206                             struct scmi_xfer *xfer);
 207         void (*mark_txdone)(struct scmi_chan_info *cinfo, int ret,
 208                             struct scmi_xfer *xfer);
 209         void (*fetch_response)(struct scmi_chan_info *cinfo,
 210                                struct scmi_xfer *xfer);
 211         void (*fetch_notification)(struct scmi_chan_info *cinfo,
 212                                    size_t max_len, struct scmi_xfer *xfer);
 213         void (*clear_channel)(struct scmi_chan_info *cinfo);
 214         bool (*poll_done)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer);
 215 };
 216
 217 /**
 218  * struct scmi_desc - Description of SoC integration
 219  *
 220  * @ops: Pointer to the transport specific ops structure
 221  * @max_rx_timeout_ms: Timeout for communication with SoC (in Milliseconds)
 222  * @max_msg: Maximum number of messages for a channel type (tx or rx) that can
 223  *      be pending simultaneously in the system. May be overridden by the
 224  *      get_max_msg op.
 225  * @max_msg_size: Maximum size of data per message that can be handled.
 226  * @force_polling: Flag to force this whole transport to use SCMI core polling
 227  *                 mechanism instead of completion interrupts even if available.
 228  * @sync_cmds_completed_on_ret: Flag to indicate that the transport assures
 229  *                              synchronous-command messages are atomically
 230  *                              completed on .send_message: no need to poll
 231  *                              actively waiting for a response.
 232  *                              Used by core internally only when polling is
 233  *                              selected as a waiting for reply method: i.e.
 234  *                              if a completion irq was found use that anyway.
 235  * @atomic_enabled: Flag to indicate that this transport, which is assured not
 236  *                  to sleep anywhere on the TX path, can be used in atomic mode
 237  *                  when requested.
 238  */
 239 struct scmi_desc {
 240         const struct scmi_transport_ops *ops;
 241         int max_rx_timeout_ms;
 242         int max_msg;
 243         int max_msg_size;
 244         const bool force_polling;
 245         const bool sync_cmds_completed_on_ret;
 246         const bool atomic_enabled;
 247 };
 248
 249 static inline bool is_polling_required(struct scmi_chan_info *cinfo,
 250                                        const struct scmi_desc *desc)
 251 {
 252         return cinfo->no_completion_irq || desc->force_polling;
 253 }
 254
 255 static inline bool is_transport_polling_capable(const struct scmi_desc *desc)
 256 {
 257         return desc->ops->poll_done || desc->sync_cmds_completed_on_ret;
 258 }
 259
 260 static inline bool is_polling_enabled(struct scmi_chan_info *cinfo,
 261                                       const struct scmi_desc *desc)
 262 {
 263         return is_polling_required(cinfo, desc) &&
 264                 is_transport_polling_capable(desc);
 265 }
 266
 267 void scmi_xfer_raw_put(const struct scmi_handle *handle,
 268                        struct scmi_xfer *xfer);
 269 struct scmi_xfer *scmi_xfer_raw_get(const struct scmi_handle *handle);
 270 struct scmi_chan_info *
 271 scmi_xfer_raw_channel_get(const struct scmi_handle *handle, u8 protocol_id);
 272
 273 int scmi_xfer_raw_inflight_register(const struct scmi_handle *handle,
 274                                     struct scmi_xfer *xfer);
 275
 276 int scmi_xfer_raw_wait_for_message_response(struct scmi_chan_info *cinfo,
 277                                             struct scmi_xfer *xfer,
 278                                             unsigned int timeout_ms);
 279
 280 enum debug_counters {
 281         SENT_OK,
 282         SENT_FAIL,
 283         SENT_FAIL_POLLING_UNSUPPORTED,
 284         SENT_FAIL_CHANNEL_NOT_FOUND,
 285         RESPONSE_OK,
 286         NOTIFICATION_OK,
 287         DELAYED_RESPONSE_OK,
 288         XFERS_RESPONSE_TIMEOUT,
 289         XFERS_RESPONSE_POLLED_TIMEOUT,
 290         RESPONSE_POLLED_OK,
 291         ERR_MSG_UNEXPECTED,
 292         ERR_MSG_INVALID,
 293         ERR_MSG_NOMEM,
 294         ERR_PROTOCOL,
 295         SCMI_DEBUG_COUNTERS_LAST
 296 };
 297
 298 static inline void scmi_inc_count(atomic_t *arr, int stat)
 299 {
 300         if (IS_ENABLED(CONFIG_ARM_SCMI_DEBUG_COUNTERS))
 301                 atomic_inc(&arr[stat]);
 302 }
 303
 304 enum scmi_bad_msg {
 305         MSG_UNEXPECTED = -1,
 306         MSG_INVALID = -2,
 307         MSG_UNKNOWN = -3,
 308         MSG_NOMEM = -4,
 309         MSG_MBOX_SPURIOUS = -5,
 310 };
 311
 312 /* shmem related declarations */
 313 struct scmi_shared_mem;
 314
 315 /**
 316  * struct scmi_shared_mem_operations  - Transport core operations for
 317  * Shared Memory
 318  *
 319  * @tx_prepare: Prepare the @xfer message for transmission on the chosen @shmem
 320  * @read_header: Read header of the message currently hold in @shmem
 321  * @fetch_response: Copy the message response from @shmem into @xfer
 322  * @fetch_notification: Copy the message notification from @shmem into @xfer
 323  * @clear_channel: Clear the @shmem channel busy flag
 324  * @poll_done: Check if poll has completed for @xfer on @shmem
 325  * @channel_free: Check if @shmem channel is marked as free
 326  * @channel_intr_enabled: Check is @shmem channel has requested a completion irq
 327  * @setup_iomap: Setup IO shared memory for channel @cinfo
 328  */
 329 struct scmi_shared_mem_operations {
 330         void (*tx_prepare)(struct scmi_shared_mem __iomem *shmem,
 331                            struct scmi_xfer *xfer,
 332                            struct scmi_chan_info *cinfo);
 333         u32 (*read_header)(struct scmi_shared_mem __iomem *shmem);
 334
 335         void (*fetch_response)(struct scmi_shared_mem __iomem *shmem,
 336                                struct scmi_xfer *xfer);
 337         void (*fetch_notification)(struct scmi_shared_mem __iomem *shmem,
 338                                    size_t max_len, struct scmi_xfer *xfer);
 339         void (*clear_channel)(struct scmi_shared_mem __iomem *shmem);
 340         bool (*poll_done)(struct scmi_shared_mem __iomem *shmem,
 341                           struct scmi_xfer *xfer);
 342         bool (*channel_free)(struct scmi_shared_mem __iomem *shmem);
 343         bool (*channel_intr_enabled)(struct scmi_shared_mem __iomem *shmem);
 344         void __iomem *(*setup_iomap)(struct scmi_chan_info *cinfo,
 345                                      struct device *dev,
 346                                      bool tx, struct resource *res);
 347 };
 348
 349 const struct scmi_shared_mem_operations *scmi_shared_mem_operations_get(void);
 350
 351 /* declarations for message passing transports */
 352 struct scmi_msg_payld;
 353
 354 /* Maximum overhead of message w.r.t. struct scmi_desc.max_msg_size */
 355 #define SCMI_MSG_MAX_PROT_OVERHEAD (2 * sizeof(__le32))
 356
 357 /**
 358  * struct scmi_message_operations  - Transport core operations for Message
 359  *
 360  * @response_size: Get calculated response size for @xfer
 361  * @command_size: Get calculated command size for @xfer
 362  * @tx_prepare: Prepare the @xfer message for transmission on the provided @msg
 363  * @read_header: Read header of the message currently hold in @msg
 364  * @fetch_response: Copy the message response from @msg into @xfer
 365  * @fetch_notification: Copy the message notification from @msg into @xfer
 366  */
 367 struct scmi_message_operations {
 368         size_t (*response_size)(struct scmi_xfer *xfer);
 369         size_t (*command_size)(struct scmi_xfer *xfer);
 370         void (*tx_prepare)(struct scmi_msg_payld *msg, struct scmi_xfer *xfer);
 371         u32 (*read_header)(struct scmi_msg_payld *msg);
 372         void (*fetch_response)(struct scmi_msg_payld *msg, size_t len,
 373                                struct scmi_xfer *xfer);
 374         void (*fetch_notification)(struct scmi_msg_payld *msg, size_t len,
 375                                    size_t max_len, struct scmi_xfer *xfer);
 376 };
 377
 378 const struct scmi_message_operations *scmi_message_operations_get(void);
 379
 380 /**
 381  * struct scmi_transport_core_operations  - Transpoert core operations
 382  *
 383  * @bad_message_trace: An helper to report a malformed/unexpected message
 384  * @rx_callback: Callback to report received messages
 385  * @shmem: Datagram operations for shared memory based transports
 386  * @msg: Datagram operations for message based transports
 387  */
 388 struct scmi_transport_core_operations {
 389         void (*bad_message_trace)(struct scmi_chan_info *cinfo,
 390                                   u32 msg_hdr, enum scmi_bad_msg err);
 391         void (*rx_callback)(struct scmi_chan_info *cinfo, u32 msg_hdr,
 392                             void *priv);
 393         const struct scmi_shared_mem_operations *shmem;
 394         const struct scmi_message_operations *msg;
 395 };
 396
 397 /**
 398  * struct scmi_transport  - A structure representing a configured transport
 399  *
 400  * @supplier: Device representing the transport and acting as a supplier for
 401  *            the core SCMI stack
 402  * @desc: Transport descriptor
 403  * @core_ops: A pointer to a pointer used by the core SCMI stack to make the
 404  *            core transport operations accessible to the transports.
 405  */
 406 struct scmi_transport {
 407         struct device *supplier;
 408         struct scmi_desc *desc;
 409         struct scmi_transport_core_operations **core_ops;
 410 };
 411
 412 #define DEFINE_SCMI_TRANSPORT_DRIVER(__tag, __drv, __desc, __match, __core_ops)\
 413 static void __tag##_dev_free(void *data)                                       \
 414 {                                                                              \
 415         struct platform_device *spdev = data;                                  \
 416                                                                                \
 417         platform_device_unregister(spdev);                                     \
 418 }                                                                              \
 419                                                                                \
 420 static int __tag##_probe(struct platform_device *pdev)                         \
 421 {                                                                              \
 422         struct device *dev = &pdev->dev;                                       \
 423         struct platform_device *spdev;                                         \
 424         struct scmi_transport strans;                                          \
 425         int ret;                                                               \
 426                                                                                \
 427         spdev = platform_device_alloc("arm-scmi", PLATFORM_DEVID_AUTO);        \
 428         if (!spdev)                                                            \
 429                 return -ENOMEM;                                                \
 430                                                                                \
 431         device_set_of_node_from_dev(&spdev->dev, dev);                         \
 432                                                                                \
 433         strans.supplier = dev;                                                 \
 434         strans.desc = &(__desc);                                               \
 435         strans.core_ops = &(__core_ops);                                       \
 436                                                                                \
 437         ret = platform_device_add_data(spdev, &strans, sizeof(strans));        \
 438         if (ret)                                                               \
 439                 goto err;                                                      \
 440                                                                                \
 441         ret = platform_device_add(spdev);                                      \
 442         if (ret)                                                               \
 443                 goto err;                                                      \
 444                                                                                \
 445         return devm_add_action_or_reset(dev, __tag##_dev_free, spdev);         \
 446                                                                                \
 447 err:                                                                           \
 448         platform_device_put(spdev);                                            \
 449         return ret;                                                            \
 450 }                                                                              \
 451                                                                                \
 452 static struct platform_driver __drv = {                                        \
 453         .driver = {                                                            \
 454                    .name = #__tag "_transport",                                \
 455                    .of_match_table = __match,                                  \
 456                    },                                                          \
 457         .probe = __tag##_probe,                                                \
 458 }
 459
 460 void scmi_notification_instance_data_set(const struct scmi_handle *handle,
 461                                          void *priv);
 462 void *scmi_notification_instance_data_get(const struct scmi_handle *handle);
 463 #endif /* _SCMI_COMMON_H */