drivers/hwtracing/coresight/ultrasoc-smb.c

   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 = 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>");