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 (atomic_read(&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 (drvdata->mode != CS_MODE_DISABLED) 211 return; 212 213 smb_enable_hw(drvdata); 214 drvdata->mode = 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 drvdata->mode = 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 (drvdata->mode != CS_MODE_DISABLED && drvdata->mode != 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 atomic_inc(&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 if (atomic_dec_return(&csdev->refcnt)) 289 return -EBUSY; 290 291 /* Complain if we (somehow) got out of sync */ 292 WARN_ON_ONCE(drvdata->mode == CS_MODE_DISABLED); 293 294 smb_disable_hw(drvdata); 295 296 /* Dissociate from the target process. */ 297 drvdata->pid = -1; 298 drvdata->mode = CS_MODE_DISABLED; 299 dev_dbg(&csdev->dev, "Ultrasoc SMB disabled\n"); 300 301 return 0; 302 } 303 304 static void *smb_alloc_buffer(struct coresight_device *csdev, 305 struct perf_event *event, void **pages, 306 int nr_pages, bool overwrite) 307 { 308 struct cs_buffers *buf; 309 int node; 310 311 node = (event->cpu == -1) ? NUMA_NO_NODE : cpu_to_node(event->cpu); 312 buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node); 313 if (!buf) 314 return NULL; 315 316 buf->snapshot = overwrite; 317 buf->nr_pages = nr_pages; 318 buf->data_pages = pages; 319 buf->pid = task_pid_nr(event->owner); 320 321 return buf; 322 } 323 324 static void smb_free_buffer(void *config) 325 { 326 struct cs_buffers *buf = config; 327 328 kfree(buf); 329 } 330 331 static void smb_sync_perf_buffer(struct smb_drv_data *drvdata, 332 struct cs_buffers *buf, 333 unsigned long head) 334 { 335 struct smb_data_buffer *sdb = &drvdata->sdb; 336 char **dst_pages = (char **)buf->data_pages; 337 unsigned long to_copy; 338 long pg_idx, pg_offset; 339 340 pg_idx = head >> PAGE_SHIFT; 341 pg_offset = head & (PAGE_SIZE - 1); 342 343 while (sdb->data_size) { 344 unsigned long pg_space = PAGE_SIZE - pg_offset; 345 346 to_copy = min(sdb->data_size, pg_space); 347 348 /* Copy parts of trace data when read pointer wrap around */ 349 if (sdb->buf_rdptr + to_copy > sdb->buf_size) 350 to_copy = sdb->buf_size - sdb->buf_rdptr; 351 352 memcpy(dst_pages[pg_idx] + pg_offset, 353 sdb->buf_base + sdb->buf_rdptr, to_copy); 354 355 pg_offset += to_copy; 356 if (pg_offset >= PAGE_SIZE) { 357 pg_offset = 0; 358 pg_idx++; 359 pg_idx %= buf->nr_pages; 360 } 361 smb_update_read_ptr(drvdata, to_copy); 362 } 363 364 smb_reset_buffer(drvdata); 365 } 366 367 static unsigned long smb_update_buffer(struct coresight_device *csdev, 368 struct perf_output_handle *handle, 369 void *sink_config) 370 { 371 struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); 372 struct smb_data_buffer *sdb = &drvdata->sdb; 373 struct cs_buffers *buf = sink_config; 374 unsigned long data_size; 375 bool lost = false; 376 377 if (!buf) 378 return 0; 379 380 guard(spinlock)(&drvdata->spinlock); 381 382 /* Don't do anything if another tracer is using this sink. */ 383 if (atomic_read(&csdev->refcnt) != 1) 384 return 0; 385 386 smb_disable_hw(drvdata); 387 smb_update_data_size(drvdata); 388 389 /* 390 * The SMB buffer may be bigger than the space available in the 391 * perf ring buffer (handle->size). If so advance the offset so 392 * that we get the latest trace data. 393 */ 394 if (sdb->data_size > handle->size) { 395 smb_update_read_ptr(drvdata, sdb->data_size - handle->size); 396 lost = true; 397 } 398 399 data_size = sdb->data_size; 400 smb_sync_perf_buffer(drvdata, buf, handle->head); 401 if (!buf->snapshot && lost) 402 perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED); 403 404 return data_size; 405 } 406 407 static const struct coresight_ops_sink smb_cs_ops = { 408 .enable = smb_enable, 409 .disable = smb_disable, 410 .alloc_buffer = smb_alloc_buffer, 411 .free_buffer = smb_free_buffer, 412 .update_buffer = smb_update_buffer, 413 }; 414 415 static const struct coresight_ops cs_ops = { 416 .sink_ops = &smb_cs_ops, 417 }; 418 419 static int smb_init_data_buffer(struct platform_device *pdev, 420 struct smb_data_buffer *sdb) 421 { 422 struct resource *res; 423 void *base; 424 425 res = platform_get_resource(pdev, IORESOURCE_MEM, SMB_BUF_ADDR_RES); 426 if (!res) { 427 dev_err(&pdev->dev, "SMB device failed to get resource\n"); 428 return -EINVAL; 429 } 430 431 sdb->buf_rdptr = 0; 432 sdb->buf_hw_base = FIELD_GET(SMB_BUF_ADDR_LO_MSK, res->start); 433 sdb->buf_size = resource_size(res); 434 if (sdb->buf_size == 0) 435 return -EINVAL; 436 437 /* 438 * This is a chunk of memory, use classic mapping with better 439 * performance. 440 */ 441 base = devm_memremap(&pdev->dev, sdb->buf_hw_base, sdb->buf_size, 442 MEMREMAP_WB); 443 if (IS_ERR(base)) 444 return PTR_ERR(base); 445 446 sdb->buf_base = base; 447 448 return 0; 449 } 450 451 static void smb_init_hw(struct smb_drv_data *drvdata) 452 { 453 smb_disable_hw(drvdata); 454 455 writel(SMB_LB_CFG_LO_DEFAULT, drvdata->base + SMB_LB_CFG_LO_REG); 456 writel(SMB_LB_CFG_HI_DEFAULT, drvdata->base + SMB_LB_CFG_HI_REG); 457 writel(SMB_GLB_CFG_DEFAULT, drvdata->base + SMB_GLB_CFG_REG); 458 writel(SMB_GLB_INT_CFG, drvdata->base + SMB_GLB_INT_REG); 459 writel(SMB_LB_INT_CTRL_CFG, drvdata->base + SMB_LB_INT_CTRL_REG); 460 } 461 462 static int smb_register_sink(struct platform_device *pdev, 463 struct smb_drv_data *drvdata) 464 { 465 struct coresight_platform_data *pdata = NULL; 466 struct coresight_desc desc = { 0 }; 467 int ret; 468 469 pdata = coresight_get_platform_data(&pdev->dev); 470 if (IS_ERR(pdata)) 471 return PTR_ERR(pdata); 472 473 desc.type = CORESIGHT_DEV_TYPE_SINK; 474 desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER; 475 desc.ops = &cs_ops; 476 desc.pdata = pdata; 477 desc.dev = &pdev->dev; 478 desc.groups = smb_sink_groups; 479 desc.name = coresight_alloc_device_name(&sink_devs, &pdev->dev); 480 if (!desc.name) { 481 dev_err(&pdev->dev, "Failed to alloc coresight device name"); 482 return -ENOMEM; 483 } 484 desc.access = CSDEV_ACCESS_IOMEM(drvdata->base); 485 486 drvdata->csdev = coresight_register(&desc); 487 if (IS_ERR(drvdata->csdev)) 488 return PTR_ERR(drvdata->csdev); 489 490 drvdata->miscdev.name = desc.name; 491 drvdata->miscdev.minor = MISC_DYNAMIC_MINOR; 492 drvdata->miscdev.fops = &smb_fops; 493 ret = misc_register(&drvdata->miscdev); 494 if (ret) { 495 coresight_unregister(drvdata->csdev); 496 dev_err(&pdev->dev, "Failed to register misc, ret=%d\n", ret); 497 } 498 499 return ret; 500 } 501 502 static void smb_unregister_sink(struct smb_drv_data *drvdata) 503 { 504 misc_deregister(&drvdata->miscdev); 505 coresight_unregister(drvdata->csdev); 506 } 507 508 static int smb_config_inport(struct device *dev, bool enable) 509 { 510 u64 func = enable ? 1 : 0; 511 union acpi_object *obj; 512 guid_t guid; 513 u64 rev = 0; 514 515 /* 516 * Using DSM calls to enable/disable ultrasoc hardwares on 517 * tracing path, to prevent ultrasoc packet format being exposed. 518 */ 519 if (guid_parse(ULTRASOC_SMB_DSM_UUID, &guid)) { 520 dev_err(dev, "Get GUID failed\n"); 521 return -EINVAL; 522 } 523 524 obj = acpi_evaluate_dsm(ACPI_HANDLE(dev), &guid, rev, func, NULL); 525 if (!obj) { 526 dev_err(dev, "ACPI handle failed\n"); 527 return -ENODEV; 528 } 529 530 ACPI_FREE(obj); 531 532 return 0; 533 } 534 535 static int smb_probe(struct platform_device *pdev) 536 { 537 struct device *dev = &pdev->dev; 538 struct smb_drv_data *drvdata; 539 int ret; 540 541 drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL); 542 if (!drvdata) 543 return -ENOMEM; 544 545 drvdata->base = devm_platform_ioremap_resource(pdev, SMB_REG_ADDR_RES); 546 if (IS_ERR(drvdata->base)) { 547 dev_err(dev, "Failed to ioremap resource\n"); 548 return PTR_ERR(drvdata->base); 549 } 550 551 smb_init_hw(drvdata); 552 553 ret = smb_init_data_buffer(pdev, &drvdata->sdb); 554 if (ret) { 555 dev_err(dev, "Failed to init buffer, ret = %d\n", ret); 556 return ret; 557 } 558 559 ret = smb_config_inport(dev, true); 560 if (ret) 561 return ret; 562 563 smb_reset_buffer(drvdata); 564 platform_set_drvdata(pdev, drvdata); 565 spin_lock_init(&drvdata->spinlock); 566 drvdata->pid = -1; 567 568 ret = smb_register_sink(pdev, drvdata); 569 if (ret) { 570 smb_config_inport(&pdev->dev, false); 571 dev_err(dev, "Failed to register SMB sink\n"); 572 return ret; 573 } 574 575 return 0; 576 } 577 578 static void smb_remove(struct platform_device *pdev) 579 { 580 struct smb_drv_data *drvdata = platform_get_drvdata(pdev); 581 582 smb_unregister_sink(drvdata); 583 584 smb_config_inport(&pdev->dev, false); 585 } 586 587 #ifdef CONFIG_ACPI 588 static const struct acpi_device_id ultrasoc_smb_acpi_match[] = { 589 {"HISI03A1", 0}, 590 {} 591 }; 592 MODULE_DEVICE_TABLE(acpi, ultrasoc_smb_acpi_match); 593 #endif 594 595 static struct platform_driver smb_driver = { 596 .driver = { 597 .name = "ultrasoc-smb", 598 .acpi_match_table = ACPI_PTR(ultrasoc_smb_acpi_match), 599 .suppress_bind_attrs = true, 600 }, 601 .probe = smb_probe, 602 .remove_new = smb_remove, 603 }; 604 module_platform_driver(smb_driver); 605 606 MODULE_DESCRIPTION("UltraSoc SMB CoreSight driver"); 607 MODULE_LICENSE("Dual MIT/GPL"); 608 MODULE_AUTHOR("Jonathan Zhou <jonathan.zhouwen@huawei.com>"); 609 MODULE_AUTHOR("Qi Liu <liuqi115@huawei.com>"); 610