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 .llseek = no_llseek, 167 }; 168 169 static ssize_t buf_size_show(struct device *dev, struct device_attribute *attr, 170 char *buf) 171 { 172 struct smb_drv_data *drvdata = dev_get_drvdata(dev->parent); 173 174 return sysfs_emit(buf, "0x%lx\n", drvdata->sdb.buf_size); 175 } 176 static DEVICE_ATTR_RO(buf_size); 177 178 static struct attribute *smb_sink_attrs[] = { 179 coresight_simple_reg32(read_pos, SMB_LB_RD_ADDR_REG), 180 coresight_simple_reg32(write_pos, SMB_LB_WR_ADDR_REG), 181 coresight_simple_reg32(buf_status, SMB_LB_INT_STS_REG), 182 &dev_attr_buf_size.attr, 183 NULL 184 }; 185 186 static const struct attribute_group smb_sink_group = { 187 .attrs = smb_sink_attrs, 188 .name = "mgmt", 189 }; 190 191 static const struct attribute_group *smb_sink_groups[] = { 192 &smb_sink_group, 193 NULL 194 }; 195 196 static void smb_enable_hw(struct smb_drv_data *drvdata) 197 { 198 writel(SMB_GLB_EN_HW_ENABLE, drvdata->base + SMB_GLB_EN_REG); 199 } 200 201 static void smb_disable_hw(struct smb_drv_data *drvdata) 202 { 203 writel(0x0, drvdata->base + SMB_GLB_EN_REG); 204 } 205 206 static void smb_enable_sysfs(struct coresight_device *csdev) 207 { 208 struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); 209 210 if (coresight_get_mode(csdev) != CS_MODE_DISABLED) 211 return; 212 213 smb_enable_hw(drvdata); 214 coresight_set_mode(csdev, CS_MODE_SYSFS); 215 } 216 217 static int smb_enable_perf(struct coresight_device *csdev, void *data) 218 { 219 struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); 220 struct perf_output_handle *handle = data; 221 struct cs_buffers *buf = etm_perf_sink_config(handle); 222 pid_t pid; 223 224 if (!buf) 225 return -EINVAL; 226 227 /* Get a handle on the pid of the target process */ 228 pid = buf->pid; 229 230 /* Device is already in used by other session */ 231 if (drvdata->pid != -1 && drvdata->pid != pid) 232 return -EBUSY; 233 234 if (drvdata->pid == -1) { 235 smb_enable_hw(drvdata); 236 drvdata->pid = pid; 237 coresight_set_mode(csdev, CS_MODE_PERF); 238 } 239 240 return 0; 241 } 242 243 static int smb_enable(struct coresight_device *csdev, enum cs_mode mode, 244 void *data) 245 { 246 struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); 247 int ret = 0; 248 249 guard(spinlock)(&drvdata->spinlock); 250 251 /* Do nothing, the trace data is reading by other interface now */ 252 if (drvdata->reading) 253 return -EBUSY; 254 255 /* Do nothing, the SMB is already enabled as other mode */ 256 if (coresight_get_mode(csdev) != CS_MODE_DISABLED && 257 coresight_get_mode(csdev) != mode) 258 return -EBUSY; 259 260 switch (mode) { 261 case CS_MODE_SYSFS: 262 smb_enable_sysfs(csdev); 263 break; 264 case CS_MODE_PERF: 265 ret = smb_enable_perf(csdev, data); 266 break; 267 default: 268 ret = -EINVAL; 269 } 270 271 if (ret) 272 return ret; 273 274 csdev->refcnt++; 275 dev_dbg(&csdev->dev, "Ultrasoc SMB enabled\n"); 276 277 return ret; 278 } 279 280 static int smb_disable(struct coresight_device *csdev) 281 { 282 struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); 283 284 guard(spinlock)(&drvdata->spinlock); 285 286 if (drvdata->reading) 287 return -EBUSY; 288 289 csdev->refcnt--; 290 if (csdev->refcnt) 291 return -EBUSY; 292 293 /* Complain if we (somehow) got out of sync */ 294 WARN_ON_ONCE(coresight_get_mode(csdev) == CS_MODE_DISABLED); 295 296 smb_disable_hw(drvdata); 297 298 /* Dissociate from the target process. */ 299 drvdata->pid = -1; 300 coresight_set_mode(csdev, CS_MODE_DISABLED); 301 dev_dbg(&csdev->dev, "Ultrasoc SMB disabled\n"); 302 303 return 0; 304 } 305 306 static void *smb_alloc_buffer(struct coresight_device *csdev, 307 struct perf_event *event, void **pages, 308 int nr_pages, bool overwrite) 309 { 310 struct cs_buffers *buf; 311 int node; 312 313 node = (event->cpu == -1) ? NUMA_NO_NODE : cpu_to_node(event->cpu); 314 buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node); 315 if (!buf) 316 return NULL; 317 318 buf->snapshot = overwrite; 319 buf->nr_pages = nr_pages; 320 buf->data_pages = pages; 321 buf->pid = task_pid_nr(event->owner); 322 323 return buf; 324 } 325 326 static void smb_free_buffer(void *config) 327 { 328 struct cs_buffers *buf = config; 329 330 kfree(buf); 331 } 332 333 static void smb_sync_perf_buffer(struct smb_drv_data *drvdata, 334 struct cs_buffers *buf, 335 unsigned long head) 336 { 337 struct smb_data_buffer *sdb = &drvdata->sdb; 338 char **dst_pages = (char **)buf->data_pages; 339 unsigned long to_copy; 340 long pg_idx, pg_offset; 341 342 pg_idx = head >> PAGE_SHIFT; 343 pg_offset = head & (PAGE_SIZE - 1); 344 345 while (sdb->data_size) { 346 unsigned long pg_space = PAGE_SIZE - pg_offset; 347 348 to_copy = min(sdb->data_size, pg_space); 349 350 /* Copy parts of trace data when read pointer wrap around */ 351 if (sdb->buf_rdptr + to_copy > sdb->buf_size) 352 to_copy = sdb->buf_size - sdb->buf_rdptr; 353 354 memcpy(dst_pages[pg_idx] + pg_offset, 355 sdb->buf_base + sdb->buf_rdptr, to_copy); 356 357 pg_offset += to_copy; 358 if (pg_offset >= PAGE_SIZE) { 359 pg_offset = 0; 360 pg_idx++; 361 pg_idx %= buf->nr_pages; 362 } 363 smb_update_read_ptr(drvdata, to_copy); 364 } 365 366 smb_reset_buffer(drvdata); 367 } 368 369 static unsigned long smb_update_buffer(struct coresight_device *csdev, 370 struct perf_output_handle *handle, 371 void *sink_config) 372 { 373 struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); 374 struct smb_data_buffer *sdb = &drvdata->sdb; 375 struct cs_buffers *buf = sink_config; 376 unsigned long data_size; 377 bool lost = false; 378 379 if (!buf) 380 return 0; 381 382 guard(spinlock)(&drvdata->spinlock); 383 384 /* Don't do anything if another tracer is using this sink. */ 385 if (csdev->refcnt != 1) 386 return 0; 387 388 smb_disable_hw(drvdata); 389 smb_update_data_size(drvdata); 390 391 /* 392 * The SMB buffer may be bigger than the space available in the 393 * perf ring buffer (handle->size). If so advance the offset so 394 * that we get the latest trace data. 395 */ 396 if (sdb->data_size > handle->size) { 397 smb_update_read_ptr(drvdata, sdb->data_size - handle->size); 398 lost = true; 399 } 400 401 data_size = sdb->data_size; 402 smb_sync_perf_buffer(drvdata, buf, handle->head); 403 if (!buf->snapshot && lost) 404 perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED); 405 406 return data_size; 407 } 408 409 static const struct coresight_ops_sink smb_cs_ops = { 410 .enable = smb_enable, 411 .disable = smb_disable, 412 .alloc_buffer = smb_alloc_buffer, 413 .free_buffer = smb_free_buffer, 414 .update_buffer = smb_update_buffer, 415 }; 416 417 static const struct coresight_ops cs_ops = { 418 .sink_ops = &smb_cs_ops, 419 }; 420 421 static int smb_init_data_buffer(struct platform_device *pdev, 422 struct smb_data_buffer *sdb) 423 { 424 struct resource *res; 425 void *base; 426 427 res = platform_get_resource(pdev, IORESOURCE_MEM, SMB_BUF_ADDR_RES); 428 if (!res) { 429 dev_err(&pdev->dev, "SMB device failed to get resource\n"); 430 return -EINVAL; 431 } 432 433 sdb->buf_rdptr = 0; 434 sdb->buf_hw_base = FIELD_GET(SMB_BUF_ADDR_LO_MSK, res->start); 435 sdb->buf_size = resource_size(res); 436 if (sdb->buf_size == 0) 437 return -EINVAL; 438 439 /* 440 * This is a chunk of memory, use classic mapping with better 441 * performance. 442 */ 443 base = devm_memremap(&pdev->dev, sdb->buf_hw_base, sdb->buf_size, 444 MEMREMAP_WB); 445 if (IS_ERR(base)) 446 return PTR_ERR(base); 447 448 sdb->buf_base = base; 449 450 return 0; 451 } 452 453 static void smb_init_hw(struct smb_drv_data *drvdata) 454 { 455 smb_disable_hw(drvdata); 456 457 writel(SMB_LB_CFG_LO_DEFAULT, drvdata->base + SMB_LB_CFG_LO_REG); 458 writel(SMB_LB_CFG_HI_DEFAULT, drvdata->base + SMB_LB_CFG_HI_REG); 459 writel(SMB_GLB_CFG_DEFAULT, drvdata->base + SMB_GLB_CFG_REG); 460 writel(SMB_GLB_INT_CFG, drvdata->base + SMB_GLB_INT_REG); 461 writel(SMB_LB_INT_CTRL_CFG, drvdata->base + SMB_LB_INT_CTRL_REG); 462 } 463 464 static int smb_register_sink(struct platform_device *pdev, 465 struct smb_drv_data *drvdata) 466 { 467 struct coresight_platform_data *pdata = NULL; 468 struct coresight_desc desc = { 0 }; 469 int ret; 470 471 pdata = coresight_get_platform_data(&pdev->dev); 472 if (IS_ERR(pdata)) 473 return PTR_ERR(pdata); 474 475 desc.type = CORESIGHT_DEV_TYPE_SINK; 476 desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER; 477 desc.ops = &cs_ops; 478 desc.pdata = pdata; 479 desc.dev = &pdev->dev; 480 desc.groups = smb_sink_groups; 481 desc.name = coresight_alloc_device_name(&sink_devs, &pdev->dev); 482 if (!desc.name) { 483 dev_err(&pdev->dev, "Failed to alloc coresight device name"); 484 return -ENOMEM; 485 } 486 desc.access = CSDEV_ACCESS_IOMEM(drvdata->base); 487 488 drvdata->csdev = coresight_register(&desc); 489 if (IS_ERR(drvdata->csdev)) 490 return PTR_ERR(drvdata->csdev); 491 492 drvdata->miscdev.name = desc.name; 493 drvdata->miscdev.minor = MISC_DYNAMIC_MINOR; 494 drvdata->miscdev.fops = &smb_fops; 495 ret = misc_register(&drvdata->miscdev); 496 if (ret) { 497 coresight_unregister(drvdata->csdev); 498 dev_err(&pdev->dev, "Failed to register misc, ret=%d\n", ret); 499 } 500 501 return ret; 502 } 503 504 static void smb_unregister_sink(struct smb_drv_data *drvdata) 505 { 506 misc_deregister(&drvdata->miscdev); 507 coresight_unregister(drvdata->csdev); 508 } 509 510 static int smb_config_inport(struct device *dev, bool enable) 511 { 512 u64 func = enable ? 1 : 0; 513 union acpi_object *obj; 514 guid_t guid; 515 u64 rev = 0; 516 517 /* 518 * Using DSM calls to enable/disable ultrasoc hardwares on 519 * tracing path, to prevent ultrasoc packet format being exposed. 520 */ 521 if (guid_parse(ULTRASOC_SMB_DSM_UUID, &guid)) { 522 dev_err(dev, "Get GUID failed\n"); 523 return -EINVAL; 524 } 525 526 obj = acpi_evaluate_dsm(ACPI_HANDLE(dev), &guid, rev, func, NULL); 527 if (!obj) { 528 dev_err(dev, "ACPI handle failed\n"); 529 return -ENODEV; 530 } 531 532 ACPI_FREE(obj); 533 534 return 0; 535 } 536 537 static int smb_probe(struct platform_device *pdev) 538 { 539 struct device *dev = &pdev->dev; 540 struct smb_drv_data *drvdata; 541 int ret; 542 543 drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL); 544 if (!drvdata) 545 return -ENOMEM; 546 547 drvdata->base = devm_platform_ioremap_resource(pdev, SMB_REG_ADDR_RES); 548 if (IS_ERR(drvdata->base)) { 549 dev_err(dev, "Failed to ioremap resource\n"); 550 return PTR_ERR(drvdata->base); 551 } 552 553 smb_init_hw(drvdata); 554 555 ret = smb_init_data_buffer(pdev, &drvdata->sdb); 556 if (ret) { 557 dev_err(dev, "Failed to init buffer, ret = %d\n", ret); 558 return ret; 559 } 560 561 ret = smb_config_inport(dev, true); 562 if (ret) 563 return ret; 564 565 smb_reset_buffer(drvdata); 566 platform_set_drvdata(pdev, drvdata); 567 spin_lock_init(&drvdata->spinlock); 568 drvdata->pid = -1; 569 570 ret = smb_register_sink(pdev, drvdata); 571 if (ret) { 572 smb_config_inport(&pdev->dev, false); 573 dev_err(dev, "Failed to register SMB sink\n"); 574 return ret; 575 } 576 577 return 0; 578 } 579 580 static void smb_remove(struct platform_device *pdev) 581 { 582 struct smb_drv_data *drvdata = platform_get_drvdata(pdev); 583 584 smb_unregister_sink(drvdata); 585 586 smb_config_inport(&pdev->dev, false); 587 } 588 589 #ifdef CONFIG_ACPI 590 static const struct acpi_device_id ultrasoc_smb_acpi_match[] = { 591 {"HISI03A1", 0, 0, 0}, 592 {} 593 }; 594 MODULE_DEVICE_TABLE(acpi, ultrasoc_smb_acpi_match); 595 #endif 596 597 static struct platform_driver smb_driver = { 598 .driver = { 599 .name = "ultrasoc-smb", 600 .acpi_match_table = ACPI_PTR(ultrasoc_smb_acpi_match), 601 .suppress_bind_attrs = true, 602 }, 603 .probe = smb_probe, 604 .remove_new = smb_remove, 605 }; 606 module_platform_driver(smb_driver); 607 608 MODULE_DESCRIPTION("UltraSoc SMB CoreSight driver"); 609 MODULE_LICENSE("Dual MIT/GPL"); 610 MODULE_AUTHOR("Jonathan Zhou <jonathan.zhouwen@huawei.com>"); 611 MODULE_AUTHOR("Qi Liu <liuqi115@huawei.com>"); 612