Bjorn Andersson | 53e2822 | 2016-09-01 15:28:09 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2015, Sony Mobile Communications AB. |
| 3 | * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved. |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License version 2 and |
| 7 | * only version 2 as published by the Free Software Foundation. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | */ |
| 14 | |
| 15 | #include <linux/interrupt.h> |
| 16 | #include <linux/io.h> |
| 17 | #include <linux/mfd/syscon.h> |
| 18 | #include <linux/module.h> |
| 19 | #include <linux/of_irq.h> |
| 20 | #include <linux/of_platform.h> |
| 21 | #include <linux/platform_device.h> |
| 22 | #include <linux/regmap.h> |
| 23 | #include <linux/sched.h> |
| 24 | #include <linux/slab.h> |
| 25 | #include <linux/soc/qcom/smem.h> |
| 26 | #include <linux/wait.h> |
| 27 | #include <linux/rpmsg.h> |
| 28 | |
| 29 | #include "rpmsg_internal.h" |
| 30 | |
| 31 | /* |
| 32 | * The Qualcomm Shared Memory communication solution provides point-to-point |
| 33 | * channels for clients to send and receive streaming or packet based data. |
| 34 | * |
| 35 | * Each channel consists of a control item (channel info) and a ring buffer |
| 36 | * pair. The channel info carry information related to channel state, flow |
| 37 | * control and the offsets within the ring buffer. |
| 38 | * |
| 39 | * All allocated channels are listed in an allocation table, identifying the |
| 40 | * pair of items by name, type and remote processor. |
| 41 | * |
| 42 | * Upon creating a new channel the remote processor allocates channel info and |
| 43 | * ring buffer items from the smem heap and populate the allocation table. An |
| 44 | * interrupt is sent to the other end of the channel and a scan for new |
| 45 | * channels should be done. A channel never goes away, it will only change |
| 46 | * state. |
| 47 | * |
| 48 | * The remote processor signals it intent for bring up the communication |
| 49 | * channel by setting the state of its end of the channel to "opening" and |
| 50 | * sends out an interrupt. We detect this change and register a smd device to |
| 51 | * consume the channel. Upon finding a consumer we finish the handshake and the |
| 52 | * channel is up. |
| 53 | * |
| 54 | * Upon closing a channel, the remote processor will update the state of its |
| 55 | * end of the channel and signal us, we will then unregister any attached |
| 56 | * device and close our end of the channel. |
| 57 | * |
| 58 | * Devices attached to a channel can use the qcom_smd_send function to push |
| 59 | * data to the channel, this is done by copying the data into the tx ring |
| 60 | * buffer, updating the pointers in the channel info and signaling the remote |
| 61 | * processor. |
| 62 | * |
| 63 | * The remote processor does the equivalent when it transfer data and upon |
| 64 | * receiving the interrupt we check the channel info for new data and delivers |
| 65 | * this to the attached device. If the device is not ready to receive the data |
| 66 | * we leave it in the ring buffer for now. |
| 67 | */ |
| 68 | |
| 69 | struct smd_channel_info; |
| 70 | struct smd_channel_info_pair; |
| 71 | struct smd_channel_info_word; |
| 72 | struct smd_channel_info_word_pair; |
| 73 | |
| 74 | static const struct rpmsg_endpoint_ops qcom_smd_endpoint_ops; |
| 75 | |
| 76 | #define SMD_ALLOC_TBL_COUNT 2 |
| 77 | #define SMD_ALLOC_TBL_SIZE 64 |
| 78 | |
| 79 | /* |
| 80 | * This lists the various smem heap items relevant for the allocation table and |
| 81 | * smd channel entries. |
| 82 | */ |
| 83 | static const struct { |
| 84 | unsigned alloc_tbl_id; |
| 85 | unsigned info_base_id; |
| 86 | unsigned fifo_base_id; |
| 87 | } smem_items[SMD_ALLOC_TBL_COUNT] = { |
| 88 | { |
| 89 | .alloc_tbl_id = 13, |
| 90 | .info_base_id = 14, |
| 91 | .fifo_base_id = 338 |
| 92 | }, |
| 93 | { |
| 94 | .alloc_tbl_id = 266, |
| 95 | .info_base_id = 138, |
| 96 | .fifo_base_id = 202, |
| 97 | }, |
| 98 | }; |
| 99 | |
| 100 | /** |
| 101 | * struct qcom_smd_edge - representing a remote processor |
| 102 | * @of_node: of_node handle for information related to this edge |
| 103 | * @edge_id: identifier of this edge |
| 104 | * @remote_pid: identifier of remote processor |
| 105 | * @irq: interrupt for signals on this edge |
| 106 | * @ipc_regmap: regmap handle holding the outgoing ipc register |
| 107 | * @ipc_offset: offset within @ipc_regmap of the register for ipc |
| 108 | * @ipc_bit: bit in the register at @ipc_offset of @ipc_regmap |
| 109 | * @channels: list of all channels detected on this edge |
| 110 | * @channels_lock: guard for modifications of @channels |
| 111 | * @allocated: array of bitmaps representing already allocated channels |
| 112 | * @smem_available: last available amount of smem triggering a channel scan |
| 113 | * @scan_work: work item for discovering new channels |
| 114 | * @state_work: work item for edge state changes |
| 115 | */ |
| 116 | struct qcom_smd_edge { |
| 117 | struct device dev; |
| 118 | |
| 119 | struct device_node *of_node; |
| 120 | unsigned edge_id; |
| 121 | unsigned remote_pid; |
| 122 | |
| 123 | int irq; |
| 124 | |
| 125 | struct regmap *ipc_regmap; |
| 126 | int ipc_offset; |
| 127 | int ipc_bit; |
| 128 | |
| 129 | struct list_head channels; |
| 130 | spinlock_t channels_lock; |
| 131 | |
| 132 | DECLARE_BITMAP(allocated[SMD_ALLOC_TBL_COUNT], SMD_ALLOC_TBL_SIZE); |
| 133 | |
| 134 | unsigned smem_available; |
| 135 | |
| 136 | wait_queue_head_t new_channel_event; |
| 137 | |
| 138 | struct work_struct scan_work; |
| 139 | struct work_struct state_work; |
| 140 | }; |
| 141 | |
| 142 | /* |
| 143 | * SMD channel states. |
| 144 | */ |
| 145 | enum smd_channel_state { |
| 146 | SMD_CHANNEL_CLOSED, |
| 147 | SMD_CHANNEL_OPENING, |
| 148 | SMD_CHANNEL_OPENED, |
| 149 | SMD_CHANNEL_FLUSHING, |
| 150 | SMD_CHANNEL_CLOSING, |
| 151 | SMD_CHANNEL_RESET, |
| 152 | SMD_CHANNEL_RESET_OPENING |
| 153 | }; |
| 154 | |
| 155 | struct qcom_smd_device { |
| 156 | struct rpmsg_device rpdev; |
| 157 | |
| 158 | struct qcom_smd_edge *edge; |
| 159 | }; |
| 160 | |
| 161 | struct qcom_smd_endpoint { |
| 162 | struct rpmsg_endpoint ept; |
| 163 | |
| 164 | struct qcom_smd_channel *qsch; |
| 165 | }; |
| 166 | |
| 167 | #define to_smd_device(_rpdev) container_of(_rpdev, struct qcom_smd_device, rpdev) |
| 168 | #define to_smd_edge(d) container_of(d, struct qcom_smd_edge, dev) |
| 169 | #define to_smd_endpoint(ept) container_of(ept, struct qcom_smd_endpoint, ept) |
| 170 | |
| 171 | /** |
| 172 | * struct qcom_smd_channel - smd channel struct |
| 173 | * @edge: qcom_smd_edge this channel is living on |
| 174 | * @qsdev: reference to a associated smd client device |
| 175 | * @name: name of the channel |
| 176 | * @state: local state of the channel |
| 177 | * @remote_state: remote state of the channel |
| 178 | * @info: byte aligned outgoing/incoming channel info |
| 179 | * @info_word: word aligned outgoing/incoming channel info |
| 180 | * @tx_lock: lock to make writes to the channel mutually exclusive |
| 181 | * @fblockread_event: wakeup event tied to tx fBLOCKREADINTR |
| 182 | * @tx_fifo: pointer to the outgoing ring buffer |
| 183 | * @rx_fifo: pointer to the incoming ring buffer |
| 184 | * @fifo_size: size of each ring buffer |
| 185 | * @bounce_buffer: bounce buffer for reading wrapped packets |
| 186 | * @cb: callback function registered for this channel |
| 187 | * @recv_lock: guard for rx info modifications and cb pointer |
| 188 | * @pkt_size: size of the currently handled packet |
| 189 | * @list: lite entry for @channels in qcom_smd_edge |
| 190 | */ |
| 191 | struct qcom_smd_channel { |
| 192 | struct qcom_smd_edge *edge; |
| 193 | |
| 194 | struct qcom_smd_endpoint *qsept; |
| 195 | bool registered; |
| 196 | |
| 197 | char *name; |
| 198 | enum smd_channel_state state; |
| 199 | enum smd_channel_state remote_state; |
| 200 | |
| 201 | struct smd_channel_info_pair *info; |
| 202 | struct smd_channel_info_word_pair *info_word; |
| 203 | |
| 204 | struct mutex tx_lock; |
| 205 | wait_queue_head_t fblockread_event; |
| 206 | |
| 207 | void *tx_fifo; |
| 208 | void *rx_fifo; |
| 209 | int fifo_size; |
| 210 | |
| 211 | void *bounce_buffer; |
| 212 | |
| 213 | spinlock_t recv_lock; |
| 214 | |
| 215 | int pkt_size; |
| 216 | |
| 217 | void *drvdata; |
| 218 | |
| 219 | struct list_head list; |
| 220 | }; |
| 221 | |
| 222 | /* |
| 223 | * Format of the smd_info smem items, for byte aligned channels. |
| 224 | */ |
| 225 | struct smd_channel_info { |
| 226 | __le32 state; |
| 227 | u8 fDSR; |
| 228 | u8 fCTS; |
| 229 | u8 fCD; |
| 230 | u8 fRI; |
| 231 | u8 fHEAD; |
| 232 | u8 fTAIL; |
| 233 | u8 fSTATE; |
| 234 | u8 fBLOCKREADINTR; |
| 235 | __le32 tail; |
| 236 | __le32 head; |
| 237 | }; |
| 238 | |
| 239 | struct smd_channel_info_pair { |
| 240 | struct smd_channel_info tx; |
| 241 | struct smd_channel_info rx; |
| 242 | }; |
| 243 | |
| 244 | /* |
| 245 | * Format of the smd_info smem items, for word aligned channels. |
| 246 | */ |
| 247 | struct smd_channel_info_word { |
| 248 | __le32 state; |
| 249 | __le32 fDSR; |
| 250 | __le32 fCTS; |
| 251 | __le32 fCD; |
| 252 | __le32 fRI; |
| 253 | __le32 fHEAD; |
| 254 | __le32 fTAIL; |
| 255 | __le32 fSTATE; |
| 256 | __le32 fBLOCKREADINTR; |
| 257 | __le32 tail; |
| 258 | __le32 head; |
| 259 | }; |
| 260 | |
| 261 | struct smd_channel_info_word_pair { |
| 262 | struct smd_channel_info_word tx; |
| 263 | struct smd_channel_info_word rx; |
| 264 | }; |
| 265 | |
| 266 | #define GET_RX_CHANNEL_FLAG(channel, param) \ |
| 267 | ({ \ |
| 268 | BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u8)); \ |
| 269 | channel->info_word ? \ |
| 270 | le32_to_cpu(channel->info_word->rx.param) : \ |
| 271 | channel->info->rx.param; \ |
| 272 | }) |
| 273 | |
| 274 | #define GET_RX_CHANNEL_INFO(channel, param) \ |
| 275 | ({ \ |
| 276 | BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u32)); \ |
| 277 | le32_to_cpu(channel->info_word ? \ |
| 278 | channel->info_word->rx.param : \ |
| 279 | channel->info->rx.param); \ |
| 280 | }) |
| 281 | |
| 282 | #define SET_RX_CHANNEL_FLAG(channel, param, value) \ |
| 283 | ({ \ |
| 284 | BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u8)); \ |
| 285 | if (channel->info_word) \ |
| 286 | channel->info_word->rx.param = cpu_to_le32(value); \ |
| 287 | else \ |
| 288 | channel->info->rx.param = value; \ |
| 289 | }) |
| 290 | |
| 291 | #define SET_RX_CHANNEL_INFO(channel, param, value) \ |
| 292 | ({ \ |
| 293 | BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u32)); \ |
| 294 | if (channel->info_word) \ |
| 295 | channel->info_word->rx.param = cpu_to_le32(value); \ |
| 296 | else \ |
| 297 | channel->info->rx.param = cpu_to_le32(value); \ |
| 298 | }) |
| 299 | |
| 300 | #define GET_TX_CHANNEL_FLAG(channel, param) \ |
| 301 | ({ \ |
| 302 | BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u8)); \ |
| 303 | channel->info_word ? \ |
| 304 | le32_to_cpu(channel->info_word->tx.param) : \ |
| 305 | channel->info->tx.param; \ |
| 306 | }) |
| 307 | |
| 308 | #define GET_TX_CHANNEL_INFO(channel, param) \ |
| 309 | ({ \ |
| 310 | BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u32)); \ |
| 311 | le32_to_cpu(channel->info_word ? \ |
| 312 | channel->info_word->tx.param : \ |
| 313 | channel->info->tx.param); \ |
| 314 | }) |
| 315 | |
| 316 | #define SET_TX_CHANNEL_FLAG(channel, param, value) \ |
| 317 | ({ \ |
| 318 | BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u8)); \ |
| 319 | if (channel->info_word) \ |
| 320 | channel->info_word->tx.param = cpu_to_le32(value); \ |
| 321 | else \ |
| 322 | channel->info->tx.param = value; \ |
| 323 | }) |
| 324 | |
| 325 | #define SET_TX_CHANNEL_INFO(channel, param, value) \ |
| 326 | ({ \ |
| 327 | BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u32)); \ |
| 328 | if (channel->info_word) \ |
| 329 | channel->info_word->tx.param = cpu_to_le32(value); \ |
| 330 | else \ |
| 331 | channel->info->tx.param = cpu_to_le32(value); \ |
| 332 | }) |
| 333 | |
| 334 | /** |
| 335 | * struct qcom_smd_alloc_entry - channel allocation entry |
| 336 | * @name: channel name |
| 337 | * @cid: channel index |
| 338 | * @flags: channel flags and edge id |
| 339 | * @ref_count: reference count of the channel |
| 340 | */ |
| 341 | struct qcom_smd_alloc_entry { |
| 342 | u8 name[20]; |
| 343 | __le32 cid; |
| 344 | __le32 flags; |
| 345 | __le32 ref_count; |
| 346 | } __packed; |
| 347 | |
| 348 | #define SMD_CHANNEL_FLAGS_EDGE_MASK 0xff |
| 349 | #define SMD_CHANNEL_FLAGS_STREAM BIT(8) |
| 350 | #define SMD_CHANNEL_FLAGS_PACKET BIT(9) |
| 351 | |
| 352 | /* |
| 353 | * Each smd packet contains a 20 byte header, with the first 4 being the length |
| 354 | * of the packet. |
| 355 | */ |
| 356 | #define SMD_PACKET_HEADER_LEN 20 |
| 357 | |
| 358 | /* |
| 359 | * Signal the remote processor associated with 'channel'. |
| 360 | */ |
| 361 | static void qcom_smd_signal_channel(struct qcom_smd_channel *channel) |
| 362 | { |
| 363 | struct qcom_smd_edge *edge = channel->edge; |
| 364 | |
| 365 | regmap_write(edge->ipc_regmap, edge->ipc_offset, BIT(edge->ipc_bit)); |
| 366 | } |
| 367 | |
| 368 | /* |
| 369 | * Initialize the tx channel info |
| 370 | */ |
| 371 | static void qcom_smd_channel_reset(struct qcom_smd_channel *channel) |
| 372 | { |
| 373 | SET_TX_CHANNEL_INFO(channel, state, SMD_CHANNEL_CLOSED); |
| 374 | SET_TX_CHANNEL_FLAG(channel, fDSR, 0); |
| 375 | SET_TX_CHANNEL_FLAG(channel, fCTS, 0); |
| 376 | SET_TX_CHANNEL_FLAG(channel, fCD, 0); |
| 377 | SET_TX_CHANNEL_FLAG(channel, fRI, 0); |
| 378 | SET_TX_CHANNEL_FLAG(channel, fHEAD, 0); |
| 379 | SET_TX_CHANNEL_FLAG(channel, fTAIL, 0); |
| 380 | SET_TX_CHANNEL_FLAG(channel, fSTATE, 1); |
| 381 | SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 1); |
| 382 | SET_TX_CHANNEL_INFO(channel, head, 0); |
| 383 | SET_RX_CHANNEL_INFO(channel, tail, 0); |
| 384 | |
| 385 | qcom_smd_signal_channel(channel); |
| 386 | |
| 387 | channel->state = SMD_CHANNEL_CLOSED; |
| 388 | channel->pkt_size = 0; |
| 389 | } |
| 390 | |
| 391 | /* |
| 392 | * Set the callback for a channel, with appropriate locking |
| 393 | */ |
| 394 | static void qcom_smd_channel_set_callback(struct qcom_smd_channel *channel, |
| 395 | rpmsg_rx_cb_t cb) |
| 396 | { |
| 397 | struct rpmsg_endpoint *ept = &channel->qsept->ept; |
| 398 | unsigned long flags; |
| 399 | |
| 400 | spin_lock_irqsave(&channel->recv_lock, flags); |
| 401 | ept->cb = cb; |
| 402 | spin_unlock_irqrestore(&channel->recv_lock, flags); |
| 403 | }; |
| 404 | |
| 405 | /* |
| 406 | * Calculate the amount of data available in the rx fifo |
| 407 | */ |
| 408 | static size_t qcom_smd_channel_get_rx_avail(struct qcom_smd_channel *channel) |
| 409 | { |
| 410 | unsigned head; |
| 411 | unsigned tail; |
| 412 | |
| 413 | head = GET_RX_CHANNEL_INFO(channel, head); |
| 414 | tail = GET_RX_CHANNEL_INFO(channel, tail); |
| 415 | |
| 416 | return (head - tail) & (channel->fifo_size - 1); |
| 417 | } |
| 418 | |
| 419 | /* |
| 420 | * Set tx channel state and inform the remote processor |
| 421 | */ |
| 422 | static void qcom_smd_channel_set_state(struct qcom_smd_channel *channel, |
| 423 | int state) |
| 424 | { |
| 425 | struct qcom_smd_edge *edge = channel->edge; |
| 426 | bool is_open = state == SMD_CHANNEL_OPENED; |
| 427 | |
| 428 | if (channel->state == state) |
| 429 | return; |
| 430 | |
| 431 | dev_dbg(&edge->dev, "set_state(%s, %d)\n", channel->name, state); |
| 432 | |
| 433 | SET_TX_CHANNEL_FLAG(channel, fDSR, is_open); |
| 434 | SET_TX_CHANNEL_FLAG(channel, fCTS, is_open); |
| 435 | SET_TX_CHANNEL_FLAG(channel, fCD, is_open); |
| 436 | |
| 437 | SET_TX_CHANNEL_INFO(channel, state, state); |
| 438 | SET_TX_CHANNEL_FLAG(channel, fSTATE, 1); |
| 439 | |
| 440 | channel->state = state; |
| 441 | qcom_smd_signal_channel(channel); |
| 442 | } |
| 443 | |
| 444 | /* |
| 445 | * Copy count bytes of data using 32bit accesses, if that's required. |
| 446 | */ |
| 447 | static void smd_copy_to_fifo(void __iomem *dst, |
| 448 | const void *src, |
| 449 | size_t count, |
| 450 | bool word_aligned) |
| 451 | { |
| 452 | if (word_aligned) { |
| 453 | __iowrite32_copy(dst, src, count / sizeof(u32)); |
| 454 | } else { |
| 455 | memcpy_toio(dst, src, count); |
| 456 | } |
| 457 | } |
| 458 | |
| 459 | /* |
| 460 | * Copy count bytes of data using 32bit accesses, if that is required. |
| 461 | */ |
| 462 | static void smd_copy_from_fifo(void *dst, |
| 463 | const void __iomem *src, |
| 464 | size_t count, |
| 465 | bool word_aligned) |
| 466 | { |
| 467 | if (word_aligned) { |
| 468 | __ioread32_copy(dst, src, count / sizeof(u32)); |
| 469 | } else { |
| 470 | memcpy_fromio(dst, src, count); |
| 471 | } |
| 472 | } |
| 473 | |
| 474 | /* |
| 475 | * Read count bytes of data from the rx fifo into buf, but don't advance the |
| 476 | * tail. |
| 477 | */ |
| 478 | static size_t qcom_smd_channel_peek(struct qcom_smd_channel *channel, |
| 479 | void *buf, size_t count) |
| 480 | { |
| 481 | bool word_aligned; |
| 482 | unsigned tail; |
| 483 | size_t len; |
| 484 | |
| 485 | word_aligned = channel->info_word; |
| 486 | tail = GET_RX_CHANNEL_INFO(channel, tail); |
| 487 | |
| 488 | len = min_t(size_t, count, channel->fifo_size - tail); |
| 489 | if (len) { |
| 490 | smd_copy_from_fifo(buf, |
| 491 | channel->rx_fifo + tail, |
| 492 | len, |
| 493 | word_aligned); |
| 494 | } |
| 495 | |
| 496 | if (len != count) { |
| 497 | smd_copy_from_fifo(buf + len, |
| 498 | channel->rx_fifo, |
| 499 | count - len, |
| 500 | word_aligned); |
| 501 | } |
| 502 | |
| 503 | return count; |
| 504 | } |
| 505 | |
| 506 | /* |
| 507 | * Advance the rx tail by count bytes. |
| 508 | */ |
| 509 | static void qcom_smd_channel_advance(struct qcom_smd_channel *channel, |
| 510 | size_t count) |
| 511 | { |
| 512 | unsigned tail; |
| 513 | |
| 514 | tail = GET_RX_CHANNEL_INFO(channel, tail); |
| 515 | tail += count; |
| 516 | tail &= (channel->fifo_size - 1); |
| 517 | SET_RX_CHANNEL_INFO(channel, tail, tail); |
| 518 | } |
| 519 | |
| 520 | /* |
| 521 | * Read out a single packet from the rx fifo and deliver it to the device |
| 522 | */ |
| 523 | static int qcom_smd_channel_recv_single(struct qcom_smd_channel *channel) |
| 524 | { |
| 525 | struct rpmsg_endpoint *ept = &channel->qsept->ept; |
| 526 | unsigned tail; |
| 527 | size_t len; |
| 528 | void *ptr; |
| 529 | int ret; |
| 530 | |
| 531 | tail = GET_RX_CHANNEL_INFO(channel, tail); |
| 532 | |
| 533 | /* Use bounce buffer if the data wraps */ |
| 534 | if (tail + channel->pkt_size >= channel->fifo_size) { |
| 535 | ptr = channel->bounce_buffer; |
| 536 | len = qcom_smd_channel_peek(channel, ptr, channel->pkt_size); |
| 537 | } else { |
| 538 | ptr = channel->rx_fifo + tail; |
| 539 | len = channel->pkt_size; |
| 540 | } |
| 541 | |
| 542 | ret = ept->cb(ept->rpdev, ptr, len, ept->priv, RPMSG_ADDR_ANY); |
| 543 | if (ret < 0) |
| 544 | return ret; |
| 545 | |
| 546 | /* Only forward the tail if the client consumed the data */ |
| 547 | qcom_smd_channel_advance(channel, len); |
| 548 | |
| 549 | channel->pkt_size = 0; |
| 550 | |
| 551 | return 0; |
| 552 | } |
| 553 | |
| 554 | /* |
| 555 | * Per channel interrupt handling |
| 556 | */ |
| 557 | static bool qcom_smd_channel_intr(struct qcom_smd_channel *channel) |
| 558 | { |
| 559 | bool need_state_scan = false; |
| 560 | int remote_state; |
| 561 | __le32 pktlen; |
| 562 | int avail; |
| 563 | int ret; |
| 564 | |
| 565 | /* Handle state changes */ |
| 566 | remote_state = GET_RX_CHANNEL_INFO(channel, state); |
| 567 | if (remote_state != channel->remote_state) { |
| 568 | channel->remote_state = remote_state; |
| 569 | need_state_scan = true; |
| 570 | } |
| 571 | /* Indicate that we have seen any state change */ |
| 572 | SET_RX_CHANNEL_FLAG(channel, fSTATE, 0); |
| 573 | |
| 574 | /* Signal waiting qcom_smd_send() about the interrupt */ |
| 575 | if (!GET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR)) |
| 576 | wake_up_interruptible(&channel->fblockread_event); |
| 577 | |
| 578 | /* Don't consume any data until we've opened the channel */ |
| 579 | if (channel->state != SMD_CHANNEL_OPENED) |
| 580 | goto out; |
| 581 | |
| 582 | /* Indicate that we've seen the new data */ |
| 583 | SET_RX_CHANNEL_FLAG(channel, fHEAD, 0); |
| 584 | |
| 585 | /* Consume data */ |
| 586 | for (;;) { |
| 587 | avail = qcom_smd_channel_get_rx_avail(channel); |
| 588 | |
| 589 | if (!channel->pkt_size && avail >= SMD_PACKET_HEADER_LEN) { |
| 590 | qcom_smd_channel_peek(channel, &pktlen, sizeof(pktlen)); |
| 591 | qcom_smd_channel_advance(channel, SMD_PACKET_HEADER_LEN); |
| 592 | channel->pkt_size = le32_to_cpu(pktlen); |
| 593 | } else if (channel->pkt_size && avail >= channel->pkt_size) { |
| 594 | ret = qcom_smd_channel_recv_single(channel); |
| 595 | if (ret) |
| 596 | break; |
| 597 | } else { |
| 598 | break; |
| 599 | } |
| 600 | } |
| 601 | |
| 602 | /* Indicate that we have seen and updated tail */ |
| 603 | SET_RX_CHANNEL_FLAG(channel, fTAIL, 1); |
| 604 | |
| 605 | /* Signal the remote that we've consumed the data (if requested) */ |
| 606 | if (!GET_RX_CHANNEL_FLAG(channel, fBLOCKREADINTR)) { |
| 607 | /* Ensure ordering of channel info updates */ |
| 608 | wmb(); |
| 609 | |
| 610 | qcom_smd_signal_channel(channel); |
| 611 | } |
| 612 | |
| 613 | out: |
| 614 | return need_state_scan; |
| 615 | } |
| 616 | |
| 617 | /* |
| 618 | * The edge interrupts are triggered by the remote processor on state changes, |
| 619 | * channel info updates or when new channels are created. |
| 620 | */ |
| 621 | static irqreturn_t qcom_smd_edge_intr(int irq, void *data) |
| 622 | { |
| 623 | struct qcom_smd_edge *edge = data; |
| 624 | struct qcom_smd_channel *channel; |
| 625 | unsigned available; |
| 626 | bool kick_scanner = false; |
| 627 | bool kick_state = false; |
| 628 | |
| 629 | /* |
| 630 | * Handle state changes or data on each of the channels on this edge |
| 631 | */ |
| 632 | spin_lock(&edge->channels_lock); |
| 633 | list_for_each_entry(channel, &edge->channels, list) { |
| 634 | spin_lock(&channel->recv_lock); |
| 635 | kick_state |= qcom_smd_channel_intr(channel); |
| 636 | spin_unlock(&channel->recv_lock); |
| 637 | } |
| 638 | spin_unlock(&edge->channels_lock); |
| 639 | |
| 640 | /* |
| 641 | * Creating a new channel requires allocating an smem entry, so we only |
| 642 | * have to scan if the amount of available space in smem have changed |
| 643 | * since last scan. |
| 644 | */ |
| 645 | available = qcom_smem_get_free_space(edge->remote_pid); |
| 646 | if (available != edge->smem_available) { |
| 647 | edge->smem_available = available; |
| 648 | kick_scanner = true; |
| 649 | } |
| 650 | |
| 651 | if (kick_scanner) |
| 652 | schedule_work(&edge->scan_work); |
| 653 | if (kick_state) |
| 654 | schedule_work(&edge->state_work); |
| 655 | |
| 656 | return IRQ_HANDLED; |
| 657 | } |
| 658 | |
| 659 | /* |
| 660 | * Calculate how much space is available in the tx fifo. |
| 661 | */ |
| 662 | static size_t qcom_smd_get_tx_avail(struct qcom_smd_channel *channel) |
| 663 | { |
| 664 | unsigned head; |
| 665 | unsigned tail; |
| 666 | unsigned mask = channel->fifo_size - 1; |
| 667 | |
| 668 | head = GET_TX_CHANNEL_INFO(channel, head); |
| 669 | tail = GET_TX_CHANNEL_INFO(channel, tail); |
| 670 | |
| 671 | return mask - ((head - tail) & mask); |
| 672 | } |
| 673 | |
| 674 | /* |
| 675 | * Write count bytes of data into channel, possibly wrapping in the ring buffer |
| 676 | */ |
| 677 | static int qcom_smd_write_fifo(struct qcom_smd_channel *channel, |
| 678 | const void *data, |
| 679 | size_t count) |
| 680 | { |
| 681 | bool word_aligned; |
| 682 | unsigned head; |
| 683 | size_t len; |
| 684 | |
| 685 | word_aligned = channel->info_word; |
| 686 | head = GET_TX_CHANNEL_INFO(channel, head); |
| 687 | |
| 688 | len = min_t(size_t, count, channel->fifo_size - head); |
| 689 | if (len) { |
| 690 | smd_copy_to_fifo(channel->tx_fifo + head, |
| 691 | data, |
| 692 | len, |
| 693 | word_aligned); |
| 694 | } |
| 695 | |
| 696 | if (len != count) { |
| 697 | smd_copy_to_fifo(channel->tx_fifo, |
| 698 | data + len, |
| 699 | count - len, |
| 700 | word_aligned); |
| 701 | } |
| 702 | |
| 703 | head += count; |
| 704 | head &= (channel->fifo_size - 1); |
| 705 | SET_TX_CHANNEL_INFO(channel, head, head); |
| 706 | |
| 707 | return count; |
| 708 | } |
| 709 | |
| 710 | /** |
| 711 | * qcom_smd_send - write data to smd channel |
| 712 | * @channel: channel handle |
| 713 | * @data: buffer of data to write |
| 714 | * @len: number of bytes to write |
| 715 | * |
| 716 | * This is a blocking write of len bytes into the channel's tx ring buffer and |
| 717 | * signal the remote end. It will sleep until there is enough space available |
| 718 | * in the tx buffer, utilizing the fBLOCKREADINTR signaling mechanism to avoid |
| 719 | * polling. |
| 720 | */ |
| 721 | static int __qcom_smd_send(struct qcom_smd_channel *channel, const void *data, |
| 722 | int len, bool wait) |
| 723 | { |
| 724 | __le32 hdr[5] = { cpu_to_le32(len), }; |
| 725 | int tlen = sizeof(hdr) + len; |
| 726 | int ret; |
| 727 | |
| 728 | /* Word aligned channels only accept word size aligned data */ |
| 729 | if (channel->info_word && len % 4) |
| 730 | return -EINVAL; |
| 731 | |
| 732 | /* Reject packets that are too big */ |
| 733 | if (tlen >= channel->fifo_size) |
| 734 | return -EINVAL; |
| 735 | |
| 736 | ret = mutex_lock_interruptible(&channel->tx_lock); |
| 737 | if (ret) |
| 738 | return ret; |
| 739 | |
| 740 | while (qcom_smd_get_tx_avail(channel) < tlen) { |
| 741 | if (!wait) { |
| 742 | ret = -ENOMEM; |
| 743 | goto out; |
| 744 | } |
| 745 | |
| 746 | if (channel->state != SMD_CHANNEL_OPENED) { |
| 747 | ret = -EPIPE; |
| 748 | goto out; |
| 749 | } |
| 750 | |
| 751 | SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 0); |
| 752 | |
| 753 | ret = wait_event_interruptible(channel->fblockread_event, |
| 754 | qcom_smd_get_tx_avail(channel) >= tlen || |
| 755 | channel->state != SMD_CHANNEL_OPENED); |
| 756 | if (ret) |
| 757 | goto out; |
| 758 | |
| 759 | SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 1); |
| 760 | } |
| 761 | |
| 762 | SET_TX_CHANNEL_FLAG(channel, fTAIL, 0); |
| 763 | |
| 764 | qcom_smd_write_fifo(channel, hdr, sizeof(hdr)); |
| 765 | qcom_smd_write_fifo(channel, data, len); |
| 766 | |
| 767 | SET_TX_CHANNEL_FLAG(channel, fHEAD, 1); |
| 768 | |
| 769 | /* Ensure ordering of channel info updates */ |
| 770 | wmb(); |
| 771 | |
| 772 | qcom_smd_signal_channel(channel); |
| 773 | |
| 774 | out: |
| 775 | mutex_unlock(&channel->tx_lock); |
| 776 | |
| 777 | return ret; |
| 778 | } |
| 779 | |
| 780 | /* |
| 781 | * Helper for opening a channel |
| 782 | */ |
| 783 | static int qcom_smd_channel_open(struct qcom_smd_channel *channel, |
| 784 | rpmsg_rx_cb_t cb) |
| 785 | { |
| 786 | size_t bb_size; |
| 787 | |
| 788 | /* |
| 789 | * Packets are maximum 4k, but reduce if the fifo is smaller |
| 790 | */ |
| 791 | bb_size = min(channel->fifo_size, SZ_4K); |
| 792 | channel->bounce_buffer = kmalloc(bb_size, GFP_KERNEL); |
| 793 | if (!channel->bounce_buffer) |
| 794 | return -ENOMEM; |
| 795 | |
| 796 | qcom_smd_channel_set_callback(channel, cb); |
| 797 | qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENING); |
| 798 | qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENED); |
| 799 | |
| 800 | return 0; |
| 801 | } |
| 802 | |
| 803 | /* |
| 804 | * Helper for closing and resetting a channel |
| 805 | */ |
| 806 | static void qcom_smd_channel_close(struct qcom_smd_channel *channel) |
| 807 | { |
| 808 | qcom_smd_channel_set_callback(channel, NULL); |
| 809 | |
| 810 | kfree(channel->bounce_buffer); |
| 811 | channel->bounce_buffer = NULL; |
| 812 | |
| 813 | qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSED); |
| 814 | qcom_smd_channel_reset(channel); |
| 815 | } |
| 816 | |
| 817 | static struct qcom_smd_channel * |
| 818 | qcom_smd_find_channel(struct qcom_smd_edge *edge, const char *name) |
| 819 | { |
| 820 | struct qcom_smd_channel *channel; |
| 821 | struct qcom_smd_channel *ret = NULL; |
| 822 | unsigned long flags; |
| 823 | unsigned state; |
| 824 | |
| 825 | spin_lock_irqsave(&edge->channels_lock, flags); |
| 826 | list_for_each_entry(channel, &edge->channels, list) { |
| 827 | if (strcmp(channel->name, name)) |
| 828 | continue; |
| 829 | |
| 830 | state = GET_RX_CHANNEL_INFO(channel, state); |
| 831 | if (state != SMD_CHANNEL_OPENING && |
| 832 | state != SMD_CHANNEL_OPENED) |
| 833 | continue; |
| 834 | |
| 835 | ret = channel; |
| 836 | break; |
| 837 | } |
| 838 | spin_unlock_irqrestore(&edge->channels_lock, flags); |
| 839 | |
| 840 | return ret; |
| 841 | } |
| 842 | |
| 843 | static void __ept_release(struct kref *kref) |
| 844 | { |
| 845 | struct rpmsg_endpoint *ept = container_of(kref, struct rpmsg_endpoint, |
| 846 | refcount); |
| 847 | kfree(to_smd_endpoint(ept)); |
| 848 | } |
| 849 | |
| 850 | static struct rpmsg_endpoint *qcom_smd_create_ept(struct rpmsg_device *rpdev, |
| 851 | rpmsg_rx_cb_t cb, void *priv, |
| 852 | struct rpmsg_channel_info chinfo) |
| 853 | { |
| 854 | struct qcom_smd_endpoint *qsept; |
| 855 | struct qcom_smd_channel *channel; |
| 856 | struct qcom_smd_device *qsdev = to_smd_device(rpdev); |
| 857 | struct qcom_smd_edge *edge = qsdev->edge; |
| 858 | struct rpmsg_endpoint *ept; |
| 859 | const char *name = chinfo.name; |
| 860 | int ret; |
| 861 | |
| 862 | /* Wait up to HZ for the channel to appear */ |
| 863 | ret = wait_event_interruptible_timeout(edge->new_channel_event, |
| 864 | (channel = qcom_smd_find_channel(edge, name)) != NULL, |
| 865 | HZ); |
| 866 | if (!ret) |
| 867 | return NULL; |
| 868 | |
| 869 | if (channel->state != SMD_CHANNEL_CLOSED) { |
| 870 | dev_err(&rpdev->dev, "channel %s is busy\n", channel->name); |
| 871 | return NULL; |
| 872 | } |
| 873 | |
| 874 | qsept = kzalloc(sizeof(*qsept), GFP_KERNEL); |
| 875 | if (!qsept) |
| 876 | return NULL; |
| 877 | |
| 878 | ept = &qsept->ept; |
| 879 | |
| 880 | kref_init(&ept->refcount); |
| 881 | |
| 882 | ept->rpdev = rpdev; |
| 883 | ept->cb = cb; |
| 884 | ept->priv = priv; |
| 885 | ept->ops = &qcom_smd_endpoint_ops; |
| 886 | |
| 887 | channel->qsept = qsept; |
| 888 | qsept->qsch = channel; |
| 889 | |
| 890 | ret = qcom_smd_channel_open(channel, cb); |
| 891 | if (ret) |
| 892 | goto free_ept; |
| 893 | |
| 894 | return ept; |
| 895 | |
| 896 | free_ept: |
| 897 | channel->qsept = NULL; |
| 898 | kref_put(&ept->refcount, __ept_release); |
| 899 | return NULL; |
| 900 | } |
| 901 | |
| 902 | static void qcom_smd_destroy_ept(struct rpmsg_endpoint *ept) |
| 903 | { |
| 904 | struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept); |
| 905 | struct qcom_smd_channel *ch = qsept->qsch; |
| 906 | |
| 907 | qcom_smd_channel_close(ch); |
| 908 | ch->qsept = NULL; |
| 909 | kref_put(&ept->refcount, __ept_release); |
| 910 | } |
| 911 | |
| 912 | static int qcom_smd_send(struct rpmsg_endpoint *ept, void *data, int len) |
| 913 | { |
| 914 | struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept); |
| 915 | |
| 916 | return __qcom_smd_send(qsept->qsch, data, len, true); |
| 917 | } |
| 918 | |
| 919 | static int qcom_smd_trysend(struct rpmsg_endpoint *ept, void *data, int len) |
| 920 | { |
| 921 | struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept); |
| 922 | |
| 923 | return __qcom_smd_send(qsept->qsch, data, len, false); |
| 924 | } |
| 925 | |
| 926 | /* |
| 927 | * Finds the device_node for the smd child interested in this channel. |
| 928 | */ |
| 929 | static struct device_node *qcom_smd_match_channel(struct device_node *edge_node, |
| 930 | const char *channel) |
| 931 | { |
| 932 | struct device_node *child; |
| 933 | const char *name; |
| 934 | const char *key; |
| 935 | int ret; |
| 936 | |
| 937 | for_each_available_child_of_node(edge_node, child) { |
| 938 | key = "qcom,smd-channels"; |
| 939 | ret = of_property_read_string(child, key, &name); |
| 940 | if (ret) |
| 941 | continue; |
| 942 | |
| 943 | if (strcmp(name, channel) == 0) |
| 944 | return child; |
| 945 | } |
| 946 | |
| 947 | return NULL; |
| 948 | } |
| 949 | |
| 950 | static const struct rpmsg_device_ops qcom_smd_device_ops = { |
| 951 | .create_ept = qcom_smd_create_ept, |
| 952 | }; |
| 953 | |
| 954 | static const struct rpmsg_endpoint_ops qcom_smd_endpoint_ops = { |
| 955 | .destroy_ept = qcom_smd_destroy_ept, |
| 956 | .send = qcom_smd_send, |
| 957 | .trysend = qcom_smd_trysend, |
| 958 | }; |
| 959 | |
| 960 | /* |
| 961 | * Create a smd client device for channel that is being opened. |
| 962 | */ |
| 963 | static int qcom_smd_create_device(struct qcom_smd_channel *channel) |
| 964 | { |
| 965 | struct qcom_smd_device *qsdev; |
| 966 | struct rpmsg_device *rpdev; |
| 967 | struct qcom_smd_edge *edge = channel->edge; |
| 968 | |
| 969 | dev_dbg(&edge->dev, "registering '%s'\n", channel->name); |
| 970 | |
| 971 | qsdev = kzalloc(sizeof(*qsdev), GFP_KERNEL); |
| 972 | if (!qsdev) |
| 973 | return -ENOMEM; |
| 974 | |
| 975 | /* Link qsdev to our SMD edge */ |
| 976 | qsdev->edge = edge; |
| 977 | |
| 978 | /* Assign callbacks for rpmsg_device */ |
| 979 | qsdev->rpdev.ops = &qcom_smd_device_ops; |
| 980 | |
| 981 | /* Assign public information to the rpmsg_device */ |
| 982 | rpdev = &qsdev->rpdev; |
| 983 | strncpy(rpdev->id.name, channel->name, RPMSG_NAME_SIZE); |
| 984 | rpdev->src = RPMSG_ADDR_ANY; |
| 985 | rpdev->dst = RPMSG_ADDR_ANY; |
| 986 | |
| 987 | rpdev->dev.of_node = qcom_smd_match_channel(edge->of_node, channel->name); |
| 988 | rpdev->dev.parent = &edge->dev; |
| 989 | |
| 990 | return rpmsg_register_device(rpdev); |
| 991 | } |
| 992 | |
| 993 | /* |
| 994 | * Allocate the qcom_smd_channel object for a newly found smd channel, |
| 995 | * retrieving and validating the smem items involved. |
| 996 | */ |
| 997 | static struct qcom_smd_channel *qcom_smd_create_channel(struct qcom_smd_edge *edge, |
| 998 | unsigned smem_info_item, |
| 999 | unsigned smem_fifo_item, |
| 1000 | char *name) |
| 1001 | { |
| 1002 | struct qcom_smd_channel *channel; |
| 1003 | size_t fifo_size; |
| 1004 | size_t info_size; |
| 1005 | void *fifo_base; |
| 1006 | void *info; |
| 1007 | int ret; |
| 1008 | |
| 1009 | channel = devm_kzalloc(&edge->dev, sizeof(*channel), GFP_KERNEL); |
| 1010 | if (!channel) |
| 1011 | return ERR_PTR(-ENOMEM); |
| 1012 | |
| 1013 | channel->edge = edge; |
| 1014 | channel->name = devm_kstrdup(&edge->dev, name, GFP_KERNEL); |
| 1015 | if (!channel->name) |
| 1016 | return ERR_PTR(-ENOMEM); |
| 1017 | |
| 1018 | mutex_init(&channel->tx_lock); |
| 1019 | spin_lock_init(&channel->recv_lock); |
| 1020 | init_waitqueue_head(&channel->fblockread_event); |
| 1021 | |
| 1022 | info = qcom_smem_get(edge->remote_pid, smem_info_item, &info_size); |
| 1023 | if (IS_ERR(info)) { |
| 1024 | ret = PTR_ERR(info); |
| 1025 | goto free_name_and_channel; |
| 1026 | } |
| 1027 | |
| 1028 | /* |
| 1029 | * Use the size of the item to figure out which channel info struct to |
| 1030 | * use. |
| 1031 | */ |
| 1032 | if (info_size == 2 * sizeof(struct smd_channel_info_word)) { |
| 1033 | channel->info_word = info; |
| 1034 | } else if (info_size == 2 * sizeof(struct smd_channel_info)) { |
| 1035 | channel->info = info; |
| 1036 | } else { |
| 1037 | dev_err(&edge->dev, |
| 1038 | "channel info of size %zu not supported\n", info_size); |
| 1039 | ret = -EINVAL; |
| 1040 | goto free_name_and_channel; |
| 1041 | } |
| 1042 | |
| 1043 | fifo_base = qcom_smem_get(edge->remote_pid, smem_fifo_item, &fifo_size); |
| 1044 | if (IS_ERR(fifo_base)) { |
| 1045 | ret = PTR_ERR(fifo_base); |
| 1046 | goto free_name_and_channel; |
| 1047 | } |
| 1048 | |
| 1049 | /* The channel consist of a rx and tx fifo of equal size */ |
| 1050 | fifo_size /= 2; |
| 1051 | |
| 1052 | dev_dbg(&edge->dev, "new channel '%s' info-size: %zu fifo-size: %zu\n", |
| 1053 | name, info_size, fifo_size); |
| 1054 | |
| 1055 | channel->tx_fifo = fifo_base; |
| 1056 | channel->rx_fifo = fifo_base + fifo_size; |
| 1057 | channel->fifo_size = fifo_size; |
| 1058 | |
| 1059 | qcom_smd_channel_reset(channel); |
| 1060 | |
| 1061 | return channel; |
| 1062 | |
| 1063 | free_name_and_channel: |
| 1064 | devm_kfree(&edge->dev, channel->name); |
| 1065 | devm_kfree(&edge->dev, channel); |
| 1066 | |
| 1067 | return ERR_PTR(ret); |
| 1068 | } |
| 1069 | |
| 1070 | /* |
| 1071 | * Scans the allocation table for any newly allocated channels, calls |
| 1072 | * qcom_smd_create_channel() to create representations of these and add |
| 1073 | * them to the edge's list of channels. |
| 1074 | */ |
| 1075 | static void qcom_channel_scan_worker(struct work_struct *work) |
| 1076 | { |
| 1077 | struct qcom_smd_edge *edge = container_of(work, struct qcom_smd_edge, scan_work); |
| 1078 | struct qcom_smd_alloc_entry *alloc_tbl; |
| 1079 | struct qcom_smd_alloc_entry *entry; |
| 1080 | struct qcom_smd_channel *channel; |
| 1081 | unsigned long flags; |
| 1082 | unsigned fifo_id; |
| 1083 | unsigned info_id; |
| 1084 | int tbl; |
| 1085 | int i; |
| 1086 | u32 eflags, cid; |
| 1087 | |
| 1088 | for (tbl = 0; tbl < SMD_ALLOC_TBL_COUNT; tbl++) { |
| 1089 | alloc_tbl = qcom_smem_get(edge->remote_pid, |
| 1090 | smem_items[tbl].alloc_tbl_id, NULL); |
| 1091 | if (IS_ERR(alloc_tbl)) |
| 1092 | continue; |
| 1093 | |
| 1094 | for (i = 0; i < SMD_ALLOC_TBL_SIZE; i++) { |
| 1095 | entry = &alloc_tbl[i]; |
| 1096 | eflags = le32_to_cpu(entry->flags); |
| 1097 | if (test_bit(i, edge->allocated[tbl])) |
| 1098 | continue; |
| 1099 | |
| 1100 | if (entry->ref_count == 0) |
| 1101 | continue; |
| 1102 | |
| 1103 | if (!entry->name[0]) |
| 1104 | continue; |
| 1105 | |
| 1106 | if (!(eflags & SMD_CHANNEL_FLAGS_PACKET)) |
| 1107 | continue; |
| 1108 | |
| 1109 | if ((eflags & SMD_CHANNEL_FLAGS_EDGE_MASK) != edge->edge_id) |
| 1110 | continue; |
| 1111 | |
| 1112 | cid = le32_to_cpu(entry->cid); |
| 1113 | info_id = smem_items[tbl].info_base_id + cid; |
| 1114 | fifo_id = smem_items[tbl].fifo_base_id + cid; |
| 1115 | |
| 1116 | channel = qcom_smd_create_channel(edge, info_id, fifo_id, entry->name); |
| 1117 | if (IS_ERR(channel)) |
| 1118 | continue; |
| 1119 | |
| 1120 | spin_lock_irqsave(&edge->channels_lock, flags); |
| 1121 | list_add(&channel->list, &edge->channels); |
| 1122 | spin_unlock_irqrestore(&edge->channels_lock, flags); |
| 1123 | |
| 1124 | dev_dbg(&edge->dev, "new channel found: '%s'\n", channel->name); |
| 1125 | set_bit(i, edge->allocated[tbl]); |
| 1126 | |
| 1127 | wake_up_interruptible(&edge->new_channel_event); |
| 1128 | } |
| 1129 | } |
| 1130 | |
| 1131 | schedule_work(&edge->state_work); |
| 1132 | } |
| 1133 | |
| 1134 | /* |
| 1135 | * This per edge worker scans smem for any new channels and register these. It |
| 1136 | * then scans all registered channels for state changes that should be handled |
| 1137 | * by creating or destroying smd client devices for the registered channels. |
| 1138 | * |
| 1139 | * LOCKING: edge->channels_lock only needs to cover the list operations, as the |
| 1140 | * worker is killed before any channels are deallocated |
| 1141 | */ |
| 1142 | static void qcom_channel_state_worker(struct work_struct *work) |
| 1143 | { |
| 1144 | struct qcom_smd_channel *channel; |
| 1145 | struct qcom_smd_edge *edge = container_of(work, |
| 1146 | struct qcom_smd_edge, |
| 1147 | state_work); |
| 1148 | struct rpmsg_channel_info chinfo; |
| 1149 | unsigned remote_state; |
| 1150 | unsigned long flags; |
| 1151 | |
| 1152 | /* |
| 1153 | * Register a device for any closed channel where the remote processor |
| 1154 | * is showing interest in opening the channel. |
| 1155 | */ |
| 1156 | spin_lock_irqsave(&edge->channels_lock, flags); |
| 1157 | list_for_each_entry(channel, &edge->channels, list) { |
| 1158 | if (channel->state != SMD_CHANNEL_CLOSED) |
| 1159 | continue; |
| 1160 | |
| 1161 | remote_state = GET_RX_CHANNEL_INFO(channel, state); |
| 1162 | if (remote_state != SMD_CHANNEL_OPENING && |
| 1163 | remote_state != SMD_CHANNEL_OPENED) |
| 1164 | continue; |
| 1165 | |
| 1166 | if (channel->registered) |
| 1167 | continue; |
| 1168 | |
| 1169 | spin_unlock_irqrestore(&edge->channels_lock, flags); |
| 1170 | qcom_smd_create_device(channel); |
| 1171 | channel->registered = true; |
| 1172 | spin_lock_irqsave(&edge->channels_lock, flags); |
| 1173 | |
| 1174 | channel->registered = true; |
| 1175 | } |
| 1176 | |
| 1177 | /* |
| 1178 | * Unregister the device for any channel that is opened where the |
| 1179 | * remote processor is closing the channel. |
| 1180 | */ |
| 1181 | list_for_each_entry(channel, &edge->channels, list) { |
| 1182 | if (channel->state != SMD_CHANNEL_OPENING && |
| 1183 | channel->state != SMD_CHANNEL_OPENED) |
| 1184 | continue; |
| 1185 | |
| 1186 | remote_state = GET_RX_CHANNEL_INFO(channel, state); |
| 1187 | if (remote_state == SMD_CHANNEL_OPENING || |
| 1188 | remote_state == SMD_CHANNEL_OPENED) |
| 1189 | continue; |
| 1190 | |
| 1191 | spin_unlock_irqrestore(&edge->channels_lock, flags); |
| 1192 | |
| 1193 | strncpy(chinfo.name, channel->name, sizeof(chinfo.name)); |
| 1194 | chinfo.src = RPMSG_ADDR_ANY; |
| 1195 | chinfo.dst = RPMSG_ADDR_ANY; |
| 1196 | rpmsg_unregister_device(&edge->dev, &chinfo); |
| 1197 | channel->registered = false; |
| 1198 | spin_lock_irqsave(&edge->channels_lock, flags); |
| 1199 | } |
| 1200 | spin_unlock_irqrestore(&edge->channels_lock, flags); |
| 1201 | } |
| 1202 | |
| 1203 | /* |
| 1204 | * Parses an of_node describing an edge. |
| 1205 | */ |
| 1206 | static int qcom_smd_parse_edge(struct device *dev, |
| 1207 | struct device_node *node, |
| 1208 | struct qcom_smd_edge *edge) |
| 1209 | { |
| 1210 | struct device_node *syscon_np; |
| 1211 | const char *key; |
| 1212 | int irq; |
| 1213 | int ret; |
| 1214 | |
| 1215 | INIT_LIST_HEAD(&edge->channels); |
| 1216 | spin_lock_init(&edge->channels_lock); |
| 1217 | |
| 1218 | INIT_WORK(&edge->scan_work, qcom_channel_scan_worker); |
| 1219 | INIT_WORK(&edge->state_work, qcom_channel_state_worker); |
| 1220 | |
| 1221 | edge->of_node = of_node_get(node); |
| 1222 | |
| 1223 | key = "qcom,smd-edge"; |
| 1224 | ret = of_property_read_u32(node, key, &edge->edge_id); |
| 1225 | if (ret) { |
| 1226 | dev_err(dev, "edge missing %s property\n", key); |
| 1227 | return -EINVAL; |
| 1228 | } |
| 1229 | |
| 1230 | edge->remote_pid = QCOM_SMEM_HOST_ANY; |
| 1231 | key = "qcom,remote-pid"; |
| 1232 | of_property_read_u32(node, key, &edge->remote_pid); |
| 1233 | |
| 1234 | syscon_np = of_parse_phandle(node, "qcom,ipc", 0); |
| 1235 | if (!syscon_np) { |
| 1236 | dev_err(dev, "no qcom,ipc node\n"); |
| 1237 | return -ENODEV; |
| 1238 | } |
| 1239 | |
| 1240 | edge->ipc_regmap = syscon_node_to_regmap(syscon_np); |
| 1241 | if (IS_ERR(edge->ipc_regmap)) |
| 1242 | return PTR_ERR(edge->ipc_regmap); |
| 1243 | |
| 1244 | key = "qcom,ipc"; |
| 1245 | ret = of_property_read_u32_index(node, key, 1, &edge->ipc_offset); |
| 1246 | if (ret < 0) { |
| 1247 | dev_err(dev, "no offset in %s\n", key); |
| 1248 | return -EINVAL; |
| 1249 | } |
| 1250 | |
| 1251 | ret = of_property_read_u32_index(node, key, 2, &edge->ipc_bit); |
| 1252 | if (ret < 0) { |
| 1253 | dev_err(dev, "no bit in %s\n", key); |
| 1254 | return -EINVAL; |
| 1255 | } |
| 1256 | |
| 1257 | irq = irq_of_parse_and_map(node, 0); |
| 1258 | if (irq < 0) { |
| 1259 | dev_err(dev, "required smd interrupt missing\n"); |
| 1260 | return -EINVAL; |
| 1261 | } |
| 1262 | |
| 1263 | ret = devm_request_irq(dev, irq, |
| 1264 | qcom_smd_edge_intr, IRQF_TRIGGER_RISING, |
| 1265 | node->name, edge); |
| 1266 | if (ret) { |
| 1267 | dev_err(dev, "failed to request smd irq\n"); |
| 1268 | return ret; |
| 1269 | } |
| 1270 | |
| 1271 | edge->irq = irq; |
| 1272 | |
| 1273 | return 0; |
| 1274 | } |
| 1275 | |
| 1276 | /* |
| 1277 | * Release function for an edge. |
| 1278 | * Reset the state of each associated channel and free the edge context. |
| 1279 | */ |
| 1280 | static void qcom_smd_edge_release(struct device *dev) |
| 1281 | { |
| 1282 | struct qcom_smd_channel *channel; |
| 1283 | struct qcom_smd_edge *edge = to_smd_edge(dev); |
| 1284 | |
| 1285 | list_for_each_entry(channel, &edge->channels, list) { |
| 1286 | SET_RX_CHANNEL_INFO(channel, state, SMD_CHANNEL_CLOSED); |
| 1287 | SET_RX_CHANNEL_INFO(channel, head, 0); |
| 1288 | SET_RX_CHANNEL_INFO(channel, tail, 0); |
| 1289 | } |
| 1290 | |
| 1291 | kfree(edge); |
| 1292 | } |
| 1293 | |
| 1294 | /** |
| 1295 | * qcom_smd_register_edge() - register an edge based on an device_node |
| 1296 | * @parent: parent device for the edge |
| 1297 | * @node: device_node describing the edge |
| 1298 | * |
| 1299 | * Returns an edge reference, or negative ERR_PTR() on failure. |
| 1300 | */ |
| 1301 | struct qcom_smd_edge *qcom_smd_register_edge(struct device *parent, |
| 1302 | struct device_node *node) |
| 1303 | { |
| 1304 | struct qcom_smd_edge *edge; |
| 1305 | int ret; |
| 1306 | |
| 1307 | edge = kzalloc(sizeof(*edge), GFP_KERNEL); |
| 1308 | if (!edge) |
| 1309 | return ERR_PTR(-ENOMEM); |
| 1310 | |
| 1311 | init_waitqueue_head(&edge->new_channel_event); |
| 1312 | |
| 1313 | edge->dev.parent = parent; |
| 1314 | edge->dev.release = qcom_smd_edge_release; |
| 1315 | dev_set_name(&edge->dev, "%s:%s", dev_name(parent), node->name); |
| 1316 | ret = device_register(&edge->dev); |
| 1317 | if (ret) { |
| 1318 | pr_err("failed to register smd edge\n"); |
| 1319 | return ERR_PTR(ret); |
| 1320 | } |
| 1321 | |
| 1322 | ret = qcom_smd_parse_edge(&edge->dev, node, edge); |
| 1323 | if (ret) { |
| 1324 | dev_err(&edge->dev, "failed to parse smd edge\n"); |
| 1325 | goto unregister_dev; |
| 1326 | } |
| 1327 | |
| 1328 | schedule_work(&edge->scan_work); |
| 1329 | |
| 1330 | return edge; |
| 1331 | |
| 1332 | unregister_dev: |
| 1333 | put_device(&edge->dev); |
| 1334 | return ERR_PTR(ret); |
| 1335 | } |
| 1336 | EXPORT_SYMBOL(qcom_smd_register_edge); |
| 1337 | |
| 1338 | static int qcom_smd_remove_device(struct device *dev, void *data) |
| 1339 | { |
| 1340 | device_unregister(dev); |
| 1341 | |
| 1342 | return 0; |
| 1343 | } |
| 1344 | |
| 1345 | /** |
| 1346 | * qcom_smd_unregister_edge() - release an edge and its children |
| 1347 | * @edge: edge reference acquired from qcom_smd_register_edge |
| 1348 | */ |
| 1349 | int qcom_smd_unregister_edge(struct qcom_smd_edge *edge) |
| 1350 | { |
| 1351 | int ret; |
| 1352 | |
| 1353 | disable_irq(edge->irq); |
| 1354 | cancel_work_sync(&edge->scan_work); |
| 1355 | cancel_work_sync(&edge->state_work); |
| 1356 | |
| 1357 | ret = device_for_each_child(&edge->dev, NULL, qcom_smd_remove_device); |
| 1358 | if (ret) |
| 1359 | dev_warn(&edge->dev, "can't remove smd device: %d\n", ret); |
| 1360 | |
| 1361 | device_unregister(&edge->dev); |
| 1362 | |
| 1363 | return 0; |
| 1364 | } |
| 1365 | EXPORT_SYMBOL(qcom_smd_unregister_edge); |
| 1366 | |
| 1367 | static int qcom_smd_probe(struct platform_device *pdev) |
| 1368 | { |
| 1369 | struct device_node *node; |
| 1370 | void *p; |
| 1371 | |
| 1372 | /* Wait for smem */ |
| 1373 | p = qcom_smem_get(QCOM_SMEM_HOST_ANY, smem_items[0].alloc_tbl_id, NULL); |
| 1374 | if (PTR_ERR(p) == -EPROBE_DEFER) |
| 1375 | return PTR_ERR(p); |
| 1376 | |
| 1377 | for_each_available_child_of_node(pdev->dev.of_node, node) |
| 1378 | qcom_smd_register_edge(&pdev->dev, node); |
| 1379 | |
| 1380 | return 0; |
| 1381 | } |
| 1382 | |
| 1383 | static int qcom_smd_remove_edge(struct device *dev, void *data) |
| 1384 | { |
| 1385 | struct qcom_smd_edge *edge = to_smd_edge(dev); |
| 1386 | |
| 1387 | return qcom_smd_unregister_edge(edge); |
| 1388 | } |
| 1389 | |
| 1390 | /* |
| 1391 | * Shut down all smd clients by making sure that each edge stops processing |
| 1392 | * events and scanning for new channels, then call destroy on the devices. |
| 1393 | */ |
| 1394 | static int qcom_smd_remove(struct platform_device *pdev) |
| 1395 | { |
| 1396 | int ret; |
| 1397 | |
| 1398 | ret = device_for_each_child(&pdev->dev, NULL, qcom_smd_remove_edge); |
| 1399 | if (ret) |
| 1400 | dev_warn(&pdev->dev, "can't remove smd device: %d\n", ret); |
| 1401 | |
| 1402 | return ret; |
| 1403 | } |
| 1404 | |
| 1405 | static const struct of_device_id qcom_smd_of_match[] = { |
| 1406 | { .compatible = "qcom,smd" }, |
| 1407 | {} |
| 1408 | }; |
| 1409 | MODULE_DEVICE_TABLE(of, qcom_smd_of_match); |
| 1410 | |
| 1411 | static struct platform_driver qcom_smd_driver = { |
| 1412 | .probe = qcom_smd_probe, |
| 1413 | .remove = qcom_smd_remove, |
| 1414 | .driver = { |
| 1415 | .name = "qcom-smd", |
| 1416 | .of_match_table = qcom_smd_of_match, |
| 1417 | }, |
| 1418 | }; |
| 1419 | |
| 1420 | static int __init qcom_smd_init(void) |
| 1421 | { |
| 1422 | return platform_driver_register(&qcom_smd_driver); |
| 1423 | } |
| 1424 | subsys_initcall(qcom_smd_init); |
| 1425 | |
| 1426 | static void __exit qcom_smd_exit(void) |
| 1427 | { |
| 1428 | platform_driver_unregister(&qcom_smd_driver); |
| 1429 | } |
| 1430 | module_exit(qcom_smd_exit); |
| 1431 | |
| 1432 | MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@sonymobile.com>"); |
| 1433 | MODULE_DESCRIPTION("Qualcomm Shared Memory Driver"); |
| 1434 | MODULE_LICENSE("GPL v2"); |