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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 20DEFINE_CORESIGHT_DEVLIST(sink_devs, "ultra_smb");21 22#define ULTRASOC_SMB_DSM_UUID "82ae1283-7f6a-4cbe-aa06-53e8fb24db18"23 24static 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 31static 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 the53 * available data size.54 */55static 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 67static 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 path74 * 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 96static 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 115static 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 150static 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 161static const struct file_operations smb_fops = {162 .owner = THIS_MODULE,163 .open = smb_open,164 .read = smb_read,165 .release = smb_release,166};167 168static 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}175static DEVICE_ATTR_RO(buf_size);176 177static 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 NULL183};184 185static const struct attribute_group smb_sink_group = {186 .attrs = smb_sink_attrs,187 .name = "mgmt",188};189 190static const struct attribute_group *smb_sink_groups[] = {191 &smb_sink_group,192 NULL193};194 195static 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 200static void smb_disable_hw(struct smb_drv_data *drvdata)201{202 writel(0x0, drvdata->base + SMB_GLB_EN_REG);203}204 205static 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 216static 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 242static 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 279static 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 305static 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 325static void smb_free_buffer(void *config)326{327 struct cs_buffers *buf = config;328 329 kfree(buf);330}331 332static 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 368static 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 the392 * perf ring buffer (handle->size). If so advance the offset so393 * 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 408static 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 416static const struct coresight_ops cs_ops = {417 .sink_ops = &smb_cs_ops,418};419 420static 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 better440 * 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 452static 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 463static 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 503static void smb_unregister_sink(struct smb_drv_data *drvdata)504{505 misc_deregister(&drvdata->miscdev);506 coresight_unregister(drvdata->csdev);507}508 509static 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 on518 * 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 536static 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 579static 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_ACPI589static const struct acpi_device_id ultrasoc_smb_acpi_match[] = {590 {"HISI03A1", 0, 0, 0},591 {}592};593MODULE_DEVICE_TABLE(acpi, ultrasoc_smb_acpi_match);594#endif595 596static 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};605module_platform_driver(smb_driver);606 607MODULE_DESCRIPTION("UltraSoc SMB CoreSight driver");608MODULE_LICENSE("Dual MIT/GPL");609MODULE_AUTHOR("Jonathan Zhou <jonathan.zhouwen@huawei.com>");610MODULE_AUTHOR("Qi Liu <liuqi115@huawei.com>");611