1 // SPDX-License-Identifier: (GPL-2.0 OR MIT) 2 /* 3 * Siemens System Memory Buffer driver. 4 * Copyright(c) 2022, HiSilicon Limited. 5 */ 6 7 #include <linux/atomic.h> 8 #include <linux/acpi.h> 9 #include <linux/circ_buf.h> 10 #include <linux/err.h> 11 #include <linux/fs.h> 12 #include <linux/module.h> 13 #include <linux/mod_devicetable.h> 14 #include <linux/platform_device.h> 15 16 #include "coresight-etm-perf.h" 17 #include "coresight-priv.h" 18 #include "ultrasoc-smb.h" 19 20 DEFINE_CORESIGHT_DEVLIST(sink_devs, "ultra_smb"); 21 22 #define ULTRASOC_SMB_DSM_UUID "82ae1283-7f6a-4cbe-aa06-53e8fb24db18" 23 24 static bool smb_buffer_not_empty(struct smb_drv_data *drvdata) 25 { 26 u32 buf_status = readl(drvdata->base + SMB_LB_INT_STS_REG); 27 28 return FIELD_GET(SMB_LB_INT_STS_NOT_EMPTY_MSK, buf_status); 29 } 30 31 static void smb_update_data_size(struct smb_drv_data *drvdata) 32 { 33 struct smb_data_buffer *sdb = &drvdata->sdb; 34 u32 buf_wrptr; 35 36 buf_wrptr = readl(drvdata->base + SMB_LB_WR_ADDR_REG) - 37 sdb->buf_hw_base; 38 39 /* Buffer is full */ 40 if (buf_wrptr == sdb->buf_rdptr && smb_buffer_not_empty(drvdata)) { 41 sdb->data_size = sdb->buf_size; 42 return; 43 } 44 45 /* The buffer mode is circular buffer mode */ 46 sdb->data_size = CIRC_CNT(buf_wrptr, sdb->buf_rdptr, 47 sdb->buf_size); 48 } 49 50 /* 51 * The read pointer adds @nbytes bytes (may round up to the beginning) 52 * after the data is read or discarded, while needing to update the 53 * available data size. 54 */ 55 static void smb_update_read_ptr(struct smb_drv_data *drvdata, u32 nbytes) 56 { 57 struct smb_data_buffer *sdb = &drvdata->sdb; 58 59 sdb->buf_rdptr += nbytes; 60 sdb->buf_rdptr %= sdb->buf_size; 61 writel(sdb->buf_hw_base + sdb->buf_rdptr, 62 drvdata->base + SMB_LB_RD_ADDR_REG); 63 64 sdb->data_size -= nbytes; 65 } 66 67 static void smb_reset_buffer(struct smb_drv_data *drvdata) 68 { 69 struct smb_data_buffer *sdb = &drvdata->sdb; 70 u32 write_ptr; 71 72 /* 73 * We must flush and discard any data left in hardware path 74 * to avoid corrupting the next session. 75 * Note: The write pointer will never exceed the read pointer. 76 */ 77 writel(SMB_LB_PURGE_PURGED, drvdata->base + SMB_LB_PURGE_REG); 78 79 /* Reset SMB logical buffer status flags */ 80 writel(SMB_LB_INT_STS_RESET, drvdata->base + SMB_LB_INT_STS_REG); 81 82 write_ptr = readl(drvdata->base + SMB_LB_WR_ADDR_REG); 83 84 /* Do nothing, not data left in hardware path */ 85 if (!write_ptr || write_ptr == sdb->buf_rdptr + sdb->buf_hw_base) 86 return; 87 88 /* 89 * The SMB_LB_WR_ADDR_REG register is read-only, 90 * Synchronize the read pointer to write pointer. 91 */ 92 writel(write_ptr, drvdata->base + SMB_LB_RD_ADDR_REG); 93 sdb->buf_rdptr = write_ptr - sdb->buf_hw_base; 94 } 95 96 static int smb_open(struct inode *inode, struct file *file) 97 { 98 struct smb_drv_data *drvdata = container_of(file->private_data, 99 struct smb_drv_data, miscdev); 100 int ret = 0; 101 102 mutex_lock(&drvdata->mutex); 103 104 if (drvdata->reading) { 105 ret = -EBUSY; 106 goto out; 107 } 108 109 if (atomic_read(drvdata->csdev->refcnt)) { 110 ret = -EBUSY; 111 goto out; 112 } 113 114 smb_update_data_size(drvdata); 115 116 drvdata->reading = true; 117 out: 118 mutex_unlock(&drvdata->mutex); 119 120 return ret; 121 } 122 123 static ssize_t smb_read(struct file *file, char __user *data, size_t len, 124 loff_t *ppos) 125 { 126 struct smb_drv_data *drvdata = container_of(file->private_data, 127 struct smb_drv_data, miscdev); 128 struct smb_data_buffer *sdb = &drvdata->sdb; 129 struct device *dev = &drvdata->csdev->dev; 130 ssize_t to_copy = 0; 131 132 if (!len) 133 return 0; 134 135 mutex_lock(&drvdata->mutex); 136 137 if (!sdb->data_size) 138 goto out; 139 140 to_copy = min(sdb->data_size, len); 141 142 /* Copy parts of trace data when read pointer wrap around SMB buffer */ 143 if (sdb->buf_rdptr + to_copy > sdb->buf_size) 144 to_copy = sdb->buf_size - sdb->buf_rdptr; 145 146 if (copy_to_user(data, sdb->buf_base + sdb->buf_rdptr, to_copy)) { 147 dev_dbg(dev, "Failed to copy data to user\n"); 148 to_copy = -EFAULT; 149 goto out; 150 } 151 152 *ppos += to_copy; 153 154 smb_update_read_ptr(drvdata, to_copy); 155 156 dev_dbg(dev, "%zu bytes copied\n", to_copy); 157 out: 158 if (!sdb->data_size) 159 smb_reset_buffer(drvdata); 160 mutex_unlock(&drvdata->mutex); 161 162 return to_copy; 163 } 164 165 static int smb_release(struct inode *inode, struct file *file) 166 { 167 struct smb_drv_data *drvdata = container_of(file->private_data, 168 struct smb_drv_data, miscdev); 169 170 mutex_lock(&drvdata->mutex); 171 drvdata->reading = false; 172 mutex_unlock(&drvdata->mutex); 173 174 return 0; 175 } 176 177 static const struct file_operations smb_fops = { 178 .owner = THIS_MODULE, 179 .open = smb_open, 180 .read = smb_read, 181 .release = smb_release, 182 .llseek = no_llseek, 183 }; 184 185 static ssize_t buf_size_show(struct device *dev, struct device_attribute *attr, 186 char *buf) 187 { 188 struct smb_drv_data *drvdata = dev_get_drvdata(dev->parent); 189 190 return sysfs_emit(buf, "0x%lx\n", drvdata->sdb.buf_size); 191 } 192 static DEVICE_ATTR_RO(buf_size); 193 194 static struct attribute *smb_sink_attrs[] = { 195 coresight_simple_reg32(read_pos, SMB_LB_RD_ADDR_REG), 196 coresight_simple_reg32(write_pos, SMB_LB_WR_ADDR_REG), 197 coresight_simple_reg32(buf_status, SMB_LB_INT_STS_REG), 198 &dev_attr_buf_size.attr, 199 NULL 200 }; 201 202 static const struct attribute_group smb_sink_group = { 203 .attrs = smb_sink_attrs, 204 .name = "mgmt", 205 }; 206 207 static const struct attribute_group *smb_sink_groups[] = { 208 &smb_sink_group, 209 NULL 210 }; 211 212 static void smb_enable_hw(struct smb_drv_data *drvdata) 213 { 214 writel(SMB_GLB_EN_HW_ENABLE, drvdata->base + SMB_GLB_EN_REG); 215 } 216 217 static void smb_disable_hw(struct smb_drv_data *drvdata) 218 { 219 writel(0x0, drvdata->base + SMB_GLB_EN_REG); 220 } 221 222 static void smb_enable_sysfs(struct coresight_device *csdev) 223 { 224 struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); 225 226 if (drvdata->mode != CS_MODE_DISABLED) 227 return; 228 229 smb_enable_hw(drvdata); 230 drvdata->mode = CS_MODE_SYSFS; 231 } 232 233 static int smb_enable_perf(struct coresight_device *csdev, void *data) 234 { 235 struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); 236 struct perf_output_handle *handle = data; 237 struct cs_buffers *buf = etm_perf_sink_config(handle); 238 pid_t pid; 239 240 if (!buf) 241 return -EINVAL; 242 243 /* Get a handle on the pid of the target process */ 244 pid = buf->pid; 245 246 /* Device is already in used by other session */ 247 if (drvdata->pid != -1 && drvdata->pid != pid) 248 return -EBUSY; 249 250 if (drvdata->pid == -1) { 251 smb_enable_hw(drvdata); 252 drvdata->pid = pid; 253 drvdata->mode = CS_MODE_PERF; 254 } 255 256 return 0; 257 } 258 259 static int smb_enable(struct coresight_device *csdev, u32 mode, void *data) 260 { 261 struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); 262 int ret = 0; 263 264 mutex_lock(&drvdata->mutex); 265 266 /* Do nothing, the trace data is reading by other interface now */ 267 if (drvdata->reading) { 268 ret = -EBUSY; 269 goto out; 270 } 271 272 /* Do nothing, the SMB is already enabled as other mode */ 273 if (drvdata->mode != CS_MODE_DISABLED && drvdata->mode != mode) { 274 ret = -EBUSY; 275 goto out; 276 } 277 278 switch (mode) { 279 case CS_MODE_SYSFS: 280 smb_enable_sysfs(csdev); 281 break; 282 case CS_MODE_PERF: 283 ret = smb_enable_perf(csdev, data); 284 break; 285 default: 286 ret = -EINVAL; 287 } 288 289 if (ret) 290 goto out; 291 292 atomic_inc(csdev->refcnt); 293 294 dev_dbg(&csdev->dev, "Ultrasoc SMB enabled\n"); 295 out: 296 mutex_unlock(&drvdata->mutex); 297 298 return ret; 299 } 300 301 static int smb_disable(struct coresight_device *csdev) 302 { 303 struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); 304 int ret = 0; 305 306 mutex_lock(&drvdata->mutex); 307 308 if (drvdata->reading) { 309 ret = -EBUSY; 310 goto out; 311 } 312 313 if (atomic_dec_return(csdev->refcnt)) { 314 ret = -EBUSY; 315 goto out; 316 } 317 318 /* Complain if we (somehow) got out of sync */ 319 WARN_ON_ONCE(drvdata->mode == CS_MODE_DISABLED); 320 321 smb_disable_hw(drvdata); 322 323 /* Dissociate from the target process. */ 324 drvdata->pid = -1; 325 drvdata->mode = CS_MODE_DISABLED; 326 327 dev_dbg(&csdev->dev, "Ultrasoc SMB disabled\n"); 328 out: 329 mutex_unlock(&drvdata->mutex); 330 331 return ret; 332 } 333 334 static void *smb_alloc_buffer(struct coresight_device *csdev, 335 struct perf_event *event, void **pages, 336 int nr_pages, bool overwrite) 337 { 338 struct cs_buffers *buf; 339 int node; 340 341 node = (event->cpu == -1) ? NUMA_NO_NODE : cpu_to_node(event->cpu); 342 buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node); 343 if (!buf) 344 return NULL; 345 346 buf->snapshot = overwrite; 347 buf->nr_pages = nr_pages; 348 buf->data_pages = pages; 349 buf->pid = task_pid_nr(event->owner); 350 351 return buf; 352 } 353 354 static void smb_free_buffer(void *config) 355 { 356 struct cs_buffers *buf = config; 357 358 kfree(buf); 359 } 360 361 static void smb_sync_perf_buffer(struct smb_drv_data *drvdata, 362 struct cs_buffers *buf, 363 unsigned long head) 364 { 365 struct smb_data_buffer *sdb = &drvdata->sdb; 366 char **dst_pages = (char **)buf->data_pages; 367 unsigned long to_copy; 368 long pg_idx, pg_offset; 369 370 pg_idx = head >> PAGE_SHIFT; 371 pg_offset = head & (PAGE_SIZE - 1); 372 373 while (sdb->data_size) { 374 unsigned long pg_space = PAGE_SIZE - pg_offset; 375 376 to_copy = min(sdb->data_size, pg_space); 377 378 /* Copy parts of trace data when read pointer wrap around */ 379 if (sdb->buf_rdptr + to_copy > sdb->buf_size) 380 to_copy = sdb->buf_size - sdb->buf_rdptr; 381 382 memcpy(dst_pages[pg_idx] + pg_offset, 383 sdb->buf_base + sdb->buf_rdptr, to_copy); 384 385 pg_offset += to_copy; 386 if (pg_offset >= PAGE_SIZE) { 387 pg_offset = 0; 388 pg_idx++; 389 pg_idx %= buf->nr_pages; 390 } 391 smb_update_read_ptr(drvdata, to_copy); 392 } 393 394 smb_reset_buffer(drvdata); 395 } 396 397 static unsigned long smb_update_buffer(struct coresight_device *csdev, 398 struct perf_output_handle *handle, 399 void *sink_config) 400 { 401 struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); 402 struct smb_data_buffer *sdb = &drvdata->sdb; 403 struct cs_buffers *buf = sink_config; 404 unsigned long data_size = 0; 405 bool lost = false; 406 407 if (!buf) 408 return 0; 409 410 mutex_lock(&drvdata->mutex); 411 412 /* Don't do anything if another tracer is using this sink. */ 413 if (atomic_read(csdev->refcnt) != 1) 414 goto out; 415 416 smb_disable_hw(drvdata); 417 smb_update_data_size(drvdata); 418 419 /* 420 * The SMB buffer may be bigger than the space available in the 421 * perf ring buffer (handle->size). If so advance the offset so 422 * that we get the latest trace data. 423 */ 424 if (sdb->data_size > handle->size) { 425 smb_update_read_ptr(drvdata, sdb->data_size - handle->size); 426 lost = true; 427 } 428 429 data_size = sdb->data_size; 430 smb_sync_perf_buffer(drvdata, buf, handle->head); 431 if (!buf->snapshot && lost) 432 perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED); 433 out: 434 mutex_unlock(&drvdata->mutex); 435 436 return data_size; 437 } 438 439 static const struct coresight_ops_sink smb_cs_ops = { 440 .enable = smb_enable, 441 .disable = smb_disable, 442 .alloc_buffer = smb_alloc_buffer, 443 .free_buffer = smb_free_buffer, 444 .update_buffer = smb_update_buffer, 445 }; 446 447 static const struct coresight_ops cs_ops = { 448 .sink_ops = &smb_cs_ops, 449 }; 450 451 static int smb_init_data_buffer(struct platform_device *pdev, 452 struct smb_data_buffer *sdb) 453 { 454 struct resource *res; 455 void *base; 456 457 res = platform_get_resource(pdev, IORESOURCE_MEM, SMB_BUF_ADDR_RES); 458 if (!res) { 459 dev_err(&pdev->dev, "SMB device failed to get resource\n"); 460 return -EINVAL; 461 } 462 463 sdb->buf_rdptr = 0; 464 sdb->buf_hw_base = FIELD_GET(SMB_BUF_ADDR_LO_MSK, res->start); 465 sdb->buf_size = resource_size(res); 466 if (sdb->buf_size == 0) 467 return -EINVAL; 468 469 /* 470 * This is a chunk of memory, use classic mapping with better 471 * performance. 472 */ 473 base = devm_memremap(&pdev->dev, sdb->buf_hw_base, sdb->buf_size, 474 MEMREMAP_WB); 475 if (IS_ERR(base)) 476 return PTR_ERR(base); 477 478 sdb->buf_base = base; 479 480 return 0; 481 } 482 483 static void smb_init_hw(struct smb_drv_data *drvdata) 484 { 485 smb_disable_hw(drvdata); 486 smb_reset_buffer(drvdata); 487 488 writel(SMB_LB_CFG_LO_DEFAULT, drvdata->base + SMB_LB_CFG_LO_REG); 489 writel(SMB_LB_CFG_HI_DEFAULT, drvdata->base + SMB_LB_CFG_HI_REG); 490 writel(SMB_GLB_CFG_DEFAULT, drvdata->base + SMB_GLB_CFG_REG); 491 writel(SMB_GLB_INT_CFG, drvdata->base + SMB_GLB_INT_REG); 492 writel(SMB_LB_INT_CTRL_CFG, drvdata->base + SMB_LB_INT_CTRL_REG); 493 } 494 495 static int smb_register_sink(struct platform_device *pdev, 496 struct smb_drv_data *drvdata) 497 { 498 struct coresight_platform_data *pdata = NULL; 499 struct coresight_desc desc = { 0 }; 500 int ret; 501 502 pdata = coresight_get_platform_data(&pdev->dev); 503 if (IS_ERR(pdata)) 504 return PTR_ERR(pdata); 505 506 desc.type = CORESIGHT_DEV_TYPE_SINK; 507 desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER; 508 desc.ops = &cs_ops; 509 desc.pdata = pdata; 510 desc.dev = &pdev->dev; 511 desc.groups = smb_sink_groups; 512 desc.name = coresight_alloc_device_name(&sink_devs, &pdev->dev); 513 if (!desc.name) { 514 dev_err(&pdev->dev, "Failed to alloc coresight device name"); 515 return -ENOMEM; 516 } 517 desc.access = CSDEV_ACCESS_IOMEM(drvdata->base); 518 519 drvdata->csdev = coresight_register(&desc); 520 if (IS_ERR(drvdata->csdev)) 521 return PTR_ERR(drvdata->csdev); 522 523 drvdata->miscdev.name = desc.name; 524 drvdata->miscdev.minor = MISC_DYNAMIC_MINOR; 525 drvdata->miscdev.fops = &smb_fops; 526 ret = misc_register(&drvdata->miscdev); 527 if (ret) { 528 coresight_unregister(drvdata->csdev); 529 dev_err(&pdev->dev, "Failed to register misc, ret=%d\n", ret); 530 } 531 532 return ret; 533 } 534 535 static void smb_unregister_sink(struct smb_drv_data *drvdata) 536 { 537 misc_deregister(&drvdata->miscdev); 538 coresight_unregister(drvdata->csdev); 539 } 540 541 static int smb_config_inport(struct device *dev, bool enable) 542 { 543 u64 func = enable ? 1 : 0; 544 union acpi_object *obj; 545 guid_t guid; 546 u64 rev = 0; 547 548 /* 549 * Using DSM calls to enable/disable ultrasoc hardwares on 550 * tracing path, to prevent ultrasoc packet format being exposed. 551 */ 552 if (guid_parse(ULTRASOC_SMB_DSM_UUID, &guid)) { 553 dev_err(dev, "Get GUID failed\n"); 554 return -EINVAL; 555 } 556 557 obj = acpi_evaluate_dsm(ACPI_HANDLE(dev), &guid, rev, func, NULL); 558 if (!obj) { 559 dev_err(dev, "ACPI handle failed\n"); 560 return -ENODEV; 561 } 562 563 ACPI_FREE(obj); 564 565 return 0; 566 } 567 568 static int smb_probe(struct platform_device *pdev) 569 { 570 struct device *dev = &pdev->dev; 571 struct smb_drv_data *drvdata; 572 int ret; 573 574 drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL); 575 if (!drvdata) 576 return -ENOMEM; 577 578 drvdata->base = devm_platform_ioremap_resource(pdev, SMB_REG_ADDR_RES); 579 if (IS_ERR(drvdata->base)) { 580 dev_err(dev, "Failed to ioremap resource\n"); 581 return PTR_ERR(drvdata->base); 582 } 583 584 smb_init_hw(drvdata); 585 586 ret = smb_init_data_buffer(pdev, &drvdata->sdb); 587 if (ret) { 588 dev_err(dev, "Failed to init buffer, ret = %d\n", ret); 589 return ret; 590 } 591 592 mutex_init(&drvdata->mutex); 593 drvdata->pid = -1; 594 595 ret = smb_register_sink(pdev, drvdata); 596 if (ret) { 597 dev_err(dev, "Failed to register SMB sink\n"); 598 return ret; 599 } 600 601 ret = smb_config_inport(dev, true); 602 if (ret) { 603 smb_unregister_sink(drvdata); 604 return ret; 605 } 606 607 platform_set_drvdata(pdev, drvdata); 608 609 return 0; 610 } 611 612 static int smb_remove(struct platform_device *pdev) 613 { 614 struct smb_drv_data *drvdata = platform_get_drvdata(pdev); 615 int ret; 616 617 ret = smb_config_inport(&pdev->dev, false); 618 if (ret) 619 return ret; 620 621 smb_unregister_sink(drvdata); 622 623 return 0; 624 } 625 626 #ifdef CONFIG_ACPI 627 static const struct acpi_device_id ultrasoc_smb_acpi_match[] = { 628 {"HISI03A1", 0}, 629 {} 630 }; 631 MODULE_DEVICE_TABLE(acpi, ultrasoc_smb_acpi_match); 632 #endif 633 634 static struct platform_driver smb_driver = { 635 .driver = { 636 .name = "ultrasoc-smb", 637 .acpi_match_table = ACPI_PTR(ultrasoc_smb_acpi_match), 638 .suppress_bind_attrs = true, 639 }, 640 .probe = smb_probe, 641 .remove = smb_remove, 642 }; 643 module_platform_driver(smb_driver); 644 645 MODULE_DESCRIPTION("UltraSoc SMB CoreSight driver"); 646 MODULE_LICENSE("Dual MIT/GPL"); 647 MODULE_AUTHOR("Jonathan Zhou <jonathan.zhouwen@huawei.com>"); 648 MODULE_AUTHOR("Qi Liu <liuqi115@huawei.com>"); 649