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); 100 101 guard(spinlock)(&drvdata->spinlock); 102 103 if (drvdata->reading) 104 return -EBUSY; 105 106 if (drvdata->csdev->refcnt) 107 return -EBUSY; 108 109 smb_update_data_size(drvdata); 110 drvdata->reading = true; 111 112 return 0; 113 } 114 115 static ssize_t smb_read(struct file *file, char __user *data, size_t len, 116 loff_t *ppos) 117 { 118 struct smb_drv_data *drvdata = container_of(file->private_data, 119 struct smb_drv_data, miscdev); 120 struct smb_data_buffer *sdb = &drvdata->sdb; 121 struct device *dev = &drvdata->csdev->dev; 122 ssize_t to_copy = 0; 123 124 if (!len) 125 return 0; 126 127 if (!sdb->data_size) 128 return 0; 129 130 to_copy = min(sdb->data_size, len); 131 132 /* Copy parts of trace data when read pointer wrap around SMB buffer */ 133 if (sdb->buf_rdptr + to_copy > sdb->buf_size) 134 to_copy = sdb->buf_size - sdb->buf_rdptr; 135 136 if (copy_to_user(data, sdb->buf_base + sdb->buf_rdptr, to_copy)) { 137 dev_dbg(dev, "Failed to copy data to user\n"); 138 return -EFAULT; 139 } 140 141 *ppos += to_copy; 142 smb_update_read_ptr(drvdata, to_copy); 143 if (!sdb->data_size) 144 smb_reset_buffer(drvdata); 145 146 dev_dbg(dev, "%zu bytes copied\n", to_copy); 147 return to_copy; 148 } 149 150 static int smb_release(struct inode *inode, struct file *file) 151 { 152 struct smb_drv_data *drvdata = container_of(file->private_data, 153 struct smb_drv_data, miscdev); 154 155 guard(spinlock)(&drvdata->spinlock); 156 drvdata->reading = false; 157 158 return 0; 159 } 160 161 static const struct file_operations smb_fops = { 162 .owner = THIS_MODULE, 163 .open = smb_open, 164 .read = smb_read, 165 .release = smb_release, 166 }; 167 168 static ssize_t buf_size_show(struct device *dev, struct device_attribute *attr, 169 char *buf) 170 { 171 struct smb_drv_data *drvdata = dev_get_drvdata(dev->parent); 172 173 return sysfs_emit(buf, "0x%lx\n", drvdata->sdb.buf_size); 174 } 175 static DEVICE_ATTR_RO(buf_size); 176 177 static struct attribute *smb_sink_attrs[] = { 178 coresight_simple_reg32(read_pos, SMB_LB_RD_ADDR_REG), 179 coresight_simple_reg32(write_pos, SMB_LB_WR_ADDR_REG), 180 coresight_simple_reg32(buf_status, SMB_LB_INT_STS_REG), 181 &dev_attr_buf_size.attr, 182 NULL 183 }; 184 185 static const struct attribute_group smb_sink_group = { 186 .attrs = smb_sink_attrs, 187 .name = "mgmt", 188 }; 189 190 static const struct attribute_group *smb_sink_groups[] = { 191 &smb_sink_group, 192 NULL 193 }; 194 195 static void smb_enable_hw(struct smb_drv_data *drvdata) 196 { 197 writel(SMB_GLB_EN_HW_ENABLE, drvdata->base + SMB_GLB_EN_REG); 198 } 199 200 static void smb_disable_hw(struct smb_drv_data *drvdata) 201 { 202 writel(0x0, drvdata->base + SMB_GLB_EN_REG); 203 } 204 205 static void smb_enable_sysfs(struct coresight_device *csdev) 206 { 207 struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); 208 209 if (coresight_get_mode(csdev) != CS_MODE_DISABLED) 210 return; 211 212 smb_enable_hw(drvdata); 213 coresight_set_mode(csdev, CS_MODE_SYSFS); 214 } 215 216 static int smb_enable_perf(struct coresight_device *csdev, void *data) 217 { 218 struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); 219 struct perf_output_handle *handle = data; 220 struct cs_buffers *buf = etm_perf_sink_config(handle); 221 pid_t pid; 222 223 if (!buf) 224 return -EINVAL; 225 226 /* Get a handle on the pid of the target process */ 227 pid = buf->pid; 228 229 /* Device is already in used by other session */ 230 if (drvdata->pid != -1 && drvdata->pid != pid) 231 return -EBUSY; 232 233 if (drvdata->pid == -1) { 234 smb_enable_hw(drvdata); 235 drvdata->pid = pid; 236 coresight_set_mode(csdev, CS_MODE_PERF); 237 } 238 239 return 0; 240 } 241 242 static int smb_enable(struct coresight_device *csdev, enum cs_mode mode, 243 void *data) 244 { 245 struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); 246 int ret = 0; 247 248 guard(spinlock)(&drvdata->spinlock); 249 250 /* Do nothing, the trace data is reading by other interface now */ 251 if (drvdata->reading) 252 return -EBUSY; 253 254 /* Do nothing, the SMB is already enabled as other mode */ 255 if (coresight_get_mode(csdev) != CS_MODE_DISABLED && 256 coresight_get_mode(csdev) != mode) 257 return -EBUSY; 258 259 switch (mode) { 260 case CS_MODE_SYSFS: 261 smb_enable_sysfs(csdev); 262 break; 263 case CS_MODE_PERF: 264 ret = smb_enable_perf(csdev, data); 265 break; 266 default: 267 ret = -EINVAL; 268 } 269 270 if (ret) 271 return ret; 272 273 csdev->refcnt++; 274 dev_dbg(&csdev->dev, "Ultrasoc SMB enabled\n"); 275 276 return ret; 277 } 278 279 static int smb_disable(struct coresight_device *csdev) 280 { 281 struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); 282 283 guard(spinlock)(&drvdata->spinlock); 284 285 if (drvdata->reading) 286 return -EBUSY; 287 288 csdev->refcnt--; 289 if (csdev->refcnt) 290 return -EBUSY; 291 292 /* Complain if we (somehow) got out of sync */ 293 WARN_ON_ONCE(coresight_get_mode(csdev) == CS_MODE_DISABLED); 294 295 smb_disable_hw(drvdata); 296 297 /* Dissociate from the target process. */ 298 drvdata->pid = -1; 299 coresight_set_mode(csdev, CS_MODE_DISABLED); 300 dev_dbg(&csdev->dev, "Ultrasoc SMB disabled\n"); 301 302 return 0; 303 } 304 305 static void *smb_alloc_buffer(struct coresight_device *csdev, 306 struct perf_event *event, void **pages, 307 int nr_pages, bool overwrite) 308 { 309 struct cs_buffers *buf; 310 int node; 311 312 node = (event->cpu == -1) ? NUMA_NO_NODE : cpu_to_node(event->cpu); 313 buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node); 314 if (!buf) 315 return NULL; 316 317 buf->snapshot = overwrite; 318 buf->nr_pages = nr_pages; 319 buf->data_pages = pages; 320 buf->pid = task_pid_nr(event->owner); 321 322 return buf; 323 } 324 325 static void smb_free_buffer(void *config) 326 { 327 struct cs_buffers *buf = config; 328 329 kfree(buf); 330 } 331 332 static void smb_sync_perf_buffer(struct smb_drv_data *drvdata, 333 struct cs_buffers *buf, 334 unsigned long head) 335 { 336 struct smb_data_buffer *sdb = &drvdata->sdb; 337 char **dst_pages = (char **)buf->data_pages; 338 unsigned long to_copy; 339 long pg_idx, pg_offset; 340 341 pg_idx = head >> PAGE_SHIFT; 342 pg_offset = head & (PAGE_SIZE - 1); 343 344 while (sdb->data_size) { 345 unsigned long pg_space = PAGE_SIZE - pg_offset; 346 347 to_copy = min(sdb->data_size, pg_space); 348 349 /* Copy parts of trace data when read pointer wrap around */ 350 if (sdb->buf_rdptr + to_copy > sdb->buf_size) 351 to_copy = sdb->buf_size - sdb->buf_rdptr; 352 353 memcpy(dst_pages[pg_idx] + pg_offset, 354 sdb->buf_base + sdb->buf_rdptr, to_copy); 355 356 pg_offset += to_copy; 357 if (pg_offset >= PAGE_SIZE) { 358 pg_offset = 0; 359 pg_idx++; 360 pg_idx %= buf->nr_pages; 361 } 362 smb_update_read_ptr(drvdata, to_copy); 363 } 364 365 smb_reset_buffer(drvdata); 366 } 367 368 static unsigned long smb_update_buffer(struct coresight_device *csdev, 369 struct perf_output_handle *handle, 370 void *sink_config) 371 { 372 struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); 373 struct smb_data_buffer *sdb = &drvdata->sdb; 374 struct cs_buffers *buf = sink_config; 375 unsigned long data_size; 376 bool lost = false; 377 378 if (!buf) 379 return 0; 380 381 guard(spinlock)(&drvdata->spinlock); 382 383 /* Don't do anything if another tracer is using this sink. */ 384 if (csdev->refcnt != 1) 385 return 0; 386 387 smb_disable_hw(drvdata); 388 smb_update_data_size(drvdata); 389 390 /* 391 * The SMB buffer may be bigger than the space available in the 392 * perf ring buffer (handle->size). If so advance the offset so 393 * that we get the latest trace data. 394 */ 395 if (sdb->data_size > handle->size) { 396 smb_update_read_ptr(drvdata, sdb->data_size - handle->size); 397 lost = true; 398 } 399 400 data_size = sdb->data_size; 401 smb_sync_perf_buffer(drvdata, buf, handle->head); 402 if (!buf->snapshot && lost) 403 perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED); 404 405 return data_size; 406 } 407 408 static const struct coresight_ops_sink smb_cs_ops = { 409 .enable = smb_enable, 410 .disable = smb_disable, 411 .alloc_buffer = smb_alloc_buffer, 412 .free_buffer = smb_free_buffer, 413 .update_buffer = smb_update_buffer, 414 }; 415 416 static const struct coresight_ops cs_ops = { 417 .sink_ops = &smb_cs_ops, 418 }; 419 420 static int smb_init_data_buffer(struct platform_device *pdev, 421 struct smb_data_buffer *sdb) 422 { 423 struct resource *res; 424 void *base; 425 426 res = platform_get_resource(pdev, IORESOURCE_MEM, SMB_BUF_ADDR_RES); 427 if (!res) { 428 dev_err(&pdev->dev, "SMB device failed to get resource\n"); 429 return -EINVAL; 430 } 431 432 sdb->buf_rdptr = 0; 433 sdb->buf_hw_base = FIELD_GET(SMB_BUF_ADDR_LO_MSK, res->start); 434 sdb->buf_size = resource_size(res); 435 if (sdb->buf_size == 0) 436 return -EINVAL; 437 438 /* 439 * This is a chunk of memory, use classic mapping with better 440 * performance. 441 */ 442 base = devm_memremap(&pdev->dev, sdb->buf_hw_base, sdb->buf_size, 443 MEMREMAP_WB); 444 if (IS_ERR(base)) 445 return PTR_ERR(base); 446 447 sdb->buf_base = base; 448 449 return 0; 450 } 451 452 static void smb_init_hw(struct smb_drv_data *drvdata) 453 { 454 smb_disable_hw(drvdata); 455 456 writel(SMB_LB_CFG_LO_DEFAULT, drvdata->base + SMB_LB_CFG_LO_REG); 457 writel(SMB_LB_CFG_HI_DEFAULT, drvdata->base + SMB_LB_CFG_HI_REG); 458 writel(SMB_GLB_CFG_DEFAULT, drvdata->base + SMB_GLB_CFG_REG); 459 writel(SMB_GLB_INT_CFG, drvdata->base + SMB_GLB_INT_REG); 460 writel(SMB_LB_INT_CTRL_CFG, drvdata->base + SMB_LB_INT_CTRL_REG); 461 } 462 463 static int smb_register_sink(struct platform_device *pdev, 464 struct smb_drv_data *drvdata) 465 { 466 struct coresight_platform_data *pdata = NULL; 467 struct coresight_desc desc = { 0 }; 468 int ret; 469 470 pdata = coresight_get_platform_data(&pdev->dev); 471 if (IS_ERR(pdata)) 472 return PTR_ERR(pdata); 473 474 desc.type = CORESIGHT_DEV_TYPE_SINK; 475 desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER; 476 desc.ops = &cs_ops; 477 desc.pdata = pdata; 478 desc.dev = &pdev->dev; 479 desc.groups = smb_sink_groups; 480 desc.name = coresight_alloc_device_name(&sink_devs, &pdev->dev); 481 if (!desc.name) { 482 dev_err(&pdev->dev, "Failed to alloc coresight device name"); 483 return -ENOMEM; 484 } 485 desc.access = CSDEV_ACCESS_IOMEM(drvdata->base); 486 487 drvdata->csdev = coresight_register(&desc); 488 if (IS_ERR(drvdata->csdev)) 489 return PTR_ERR(drvdata->csdev); 490 491 drvdata->miscdev.name = desc.name; 492 drvdata->miscdev.minor = MISC_DYNAMIC_MINOR; 493 drvdata->miscdev.fops = &smb_fops; 494 ret = misc_register(&drvdata->miscdev); 495 if (ret) { 496 coresight_unregister(drvdata->csdev); 497 dev_err(&pdev->dev, "Failed to register misc, ret=%d\n", ret); 498 } 499 500 return ret; 501 } 502 503 static void smb_unregister_sink(struct smb_drv_data *drvdata) 504 { 505 misc_deregister(&drvdata->miscdev); 506 coresight_unregister(drvdata->csdev); 507 } 508 509 static int smb_config_inport(struct device *dev, bool enable) 510 { 511 u64 func = enable ? 1 : 0; 512 union acpi_object *obj; 513 guid_t guid; 514 u64 rev = 0; 515 516 /* 517 * Using DSM calls to enable/disable ultrasoc hardwares on 518 * tracing path, to prevent ultrasoc packet format being exposed. 519 */ 520 if (guid_parse(ULTRASOC_SMB_DSM_UUID, &guid)) { 521 dev_err(dev, "Get GUID failed\n"); 522 return -EINVAL; 523 } 524 525 obj = acpi_evaluate_dsm(ACPI_HANDLE(dev), &guid, rev, func, NULL); 526 if (!obj) { 527 dev_err(dev, "ACPI handle failed\n"); 528 return -ENODEV; 529 } 530 531 ACPI_FREE(obj); 532 533 return 0; 534 } 535 536 static int smb_probe(struct platform_device *pdev) 537 { 538 struct device *dev = &pdev->dev; 539 struct smb_drv_data *drvdata; 540 int ret; 541 542 drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL); 543 if (!drvdata) 544 return -ENOMEM; 545 546 drvdata->base = devm_platform_ioremap_resource(pdev, SMB_REG_ADDR_RES); 547 if (IS_ERR(drvdata->base)) { 548 dev_err(dev, "Failed to ioremap resource\n"); 549 return PTR_ERR(drvdata->base); 550 } 551 552 smb_init_hw(drvdata); 553 554 ret = smb_init_data_buffer(pdev, &drvdata->sdb); 555 if (ret) { 556 dev_err(dev, "Failed to init buffer, ret = %d\n", ret); 557 return ret; 558 } 559 560 ret = smb_config_inport(dev, true); 561 if (ret) 562 return ret; 563 564 smb_reset_buffer(drvdata); 565 platform_set_drvdata(pdev, drvdata); 566 spin_lock_init(&drvdata->spinlock); 567 drvdata->pid = -1; 568 569 ret = smb_register_sink(pdev, drvdata); 570 if (ret) { 571 smb_config_inport(&pdev->dev, false); 572 dev_err(dev, "Failed to register SMB sink\n"); 573 return ret; 574 } 575 576 return 0; 577 } 578 579 static void smb_remove(struct platform_device *pdev) 580 { 581 struct smb_drv_data *drvdata = platform_get_drvdata(pdev); 582 583 smb_unregister_sink(drvdata); 584 585 smb_config_inport(&pdev->dev, false); 586 } 587 588 #ifdef CONFIG_ACPI 589 static const struct acpi_device_id ultrasoc_smb_acpi_match[] = { 590 {"HISI03A1", 0, 0, 0}, 591 {} 592 }; 593 MODULE_DEVICE_TABLE(acpi, ultrasoc_smb_acpi_match); 594 #endif 595 596 static struct platform_driver smb_driver = { 597 .driver = { 598 .name = "ultrasoc-smb", 599 .acpi_match_table = ACPI_PTR(ultrasoc_smb_acpi_match), 600 .suppress_bind_attrs = true, 601 }, 602 .probe = smb_probe, 603 .remove_new = smb_remove, 604 }; 605 module_platform_driver(smb_driver); 606 607 MODULE_DESCRIPTION("UltraSoc SMB CoreSight driver"); 608 MODULE_LICENSE("Dual MIT/GPL"); 609 MODULE_AUTHOR("Jonathan Zhou <jonathan.zhouwen@huawei.com>"); 610 MODULE_AUTHOR("Qi Liu <liuqi115@huawei.com>"); 611