1 // SPDX-License-Identifier: (GPL-2.0 OR MIT)
3 * Siemens System Memory Buffer driver.
4 * Copyright(c) 2022, HiSilicon Limited.
7 #include <linux/atomic.h>
8 #include <linux/acpi.h>
9 #include <linux/circ_buf.h>
10 #include <linux/err.h>
12 #include <linux/module.h>
13 #include <linux/mod_devicetable.h>
14 #include <linux/platform_device.h>
16 #include "coresight-etm-perf.h"
17 #include "coresight-priv.h"
18 #include "ultrasoc-smb.h"
20 DEFINE_CORESIGHT_DEVLIST(sink_devs, "ultra_smb");
22 #define ULTRASOC_SMB_DSM_UUID "82ae1283-7f6a-4cbe-aa06-53e8fb24db18"
24 static bool smb_buffer_not_empty(struct smb_drv_data *drvdata)
26 u32 buf_status = readl(drvdata->base + SMB_LB_INT_STS_REG);
28 return FIELD_GET(SMB_LB_INT_STS_NOT_EMPTY_MSK, buf_status);
31 static void smb_update_data_size(struct smb_drv_data *drvdata)
33 struct smb_data_buffer *sdb = &drvdata->sdb;
36 buf_wrptr = readl(drvdata->base + SMB_LB_WR_ADDR_REG) -
40 if (buf_wrptr == sdb->buf_rdptr && smb_buffer_not_empty(drvdata)) {
41 sdb->data_size = sdb->buf_size;
45 /* The buffer mode is circular buffer mode */
46 sdb->data_size = CIRC_CNT(buf_wrptr, sdb->buf_rdptr,
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.
55 static void smb_update_read_ptr(struct smb_drv_data *drvdata, u32 nbytes)
57 struct smb_data_buffer *sdb = &drvdata->sdb;
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);
64 sdb->data_size -= nbytes;
67 static void smb_reset_buffer(struct smb_drv_data *drvdata)
69 struct smb_data_buffer *sdb = &drvdata->sdb;
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.
77 writel(SMB_LB_PURGE_PURGED, drvdata->base + SMB_LB_PURGE_REG);
79 /* Reset SMB logical buffer status flags */
80 writel(SMB_LB_INT_STS_RESET, drvdata->base + SMB_LB_INT_STS_REG);
82 write_ptr = readl(drvdata->base + SMB_LB_WR_ADDR_REG);
84 /* Do nothing, not data left in hardware path */
85 if (!write_ptr || write_ptr == sdb->buf_rdptr + sdb->buf_hw_base)
89 * The SMB_LB_WR_ADDR_REG register is read-only,
90 * Synchronize the read pointer to write pointer.
92 writel(write_ptr, drvdata->base + SMB_LB_RD_ADDR_REG);
93 sdb->buf_rdptr = write_ptr - sdb->buf_hw_base;
96 static int smb_open(struct inode *inode, struct file *file)
98 struct smb_drv_data *drvdata = container_of(file->private_data,
99 struct smb_drv_data, miscdev);
102 spin_lock(&drvdata->spinlock);
104 if (drvdata->reading) {
109 if (atomic_read(&drvdata->csdev->refcnt)) {
114 smb_update_data_size(drvdata);
116 drvdata->reading = true;
118 spin_unlock(&drvdata->spinlock);
123 static ssize_t smb_read(struct file *file, char __user *data, size_t len,
126 struct smb_drv_data *drvdata = container_of(file->private_data,
127 struct smb_drv_data, miscdev);
128 struct smb_data_buffer *sdb = &drvdata->sdb;
129 struct device *dev = &drvdata->csdev->dev;
138 to_copy = min(sdb->data_size, len);
140 /* Copy parts of trace data when read pointer wrap around SMB buffer */
141 if (sdb->buf_rdptr + to_copy > sdb->buf_size)
142 to_copy = sdb->buf_size - sdb->buf_rdptr;
144 if (copy_to_user(data, sdb->buf_base + sdb->buf_rdptr, to_copy)) {
145 dev_dbg(dev, "Failed to copy data to user\n");
150 smb_update_read_ptr(drvdata, to_copy);
152 smb_reset_buffer(drvdata);
154 dev_dbg(dev, "%zu bytes copied\n", to_copy);
158 static int smb_release(struct inode *inode, struct file *file)
160 struct smb_drv_data *drvdata = container_of(file->private_data,
161 struct smb_drv_data, miscdev);
163 spin_lock(&drvdata->spinlock);
164 drvdata->reading = false;
165 spin_unlock(&drvdata->spinlock);
170 static const struct file_operations smb_fops = {
171 .owner = THIS_MODULE,
174 .release = smb_release,
178 static ssize_t buf_size_show(struct device *dev, struct device_attribute *attr,
181 struct smb_drv_data *drvdata = dev_get_drvdata(dev->parent);
183 return sysfs_emit(buf, "0x%lx\n", drvdata->sdb.buf_size);
185 static DEVICE_ATTR_RO(buf_size);
187 static struct attribute *smb_sink_attrs[] = {
188 coresight_simple_reg32(read_pos, SMB_LB_RD_ADDR_REG),
189 coresight_simple_reg32(write_pos, SMB_LB_WR_ADDR_REG),
190 coresight_simple_reg32(buf_status, SMB_LB_INT_STS_REG),
191 &dev_attr_buf_size.attr,
195 static const struct attribute_group smb_sink_group = {
196 .attrs = smb_sink_attrs,
200 static const struct attribute_group *smb_sink_groups[] = {
205 static void smb_enable_hw(struct smb_drv_data *drvdata)
207 writel(SMB_GLB_EN_HW_ENABLE, drvdata->base + SMB_GLB_EN_REG);
210 static void smb_disable_hw(struct smb_drv_data *drvdata)
212 writel(0x0, drvdata->base + SMB_GLB_EN_REG);
215 static void smb_enable_sysfs(struct coresight_device *csdev)
217 struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
219 if (drvdata->mode != CS_MODE_DISABLED)
222 smb_enable_hw(drvdata);
223 drvdata->mode = CS_MODE_SYSFS;
226 static int smb_enable_perf(struct coresight_device *csdev, void *data)
228 struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
229 struct perf_output_handle *handle = data;
230 struct cs_buffers *buf = etm_perf_sink_config(handle);
236 /* Get a handle on the pid of the target process */
239 /* Device is already in used by other session */
240 if (drvdata->pid != -1 && drvdata->pid != pid)
243 if (drvdata->pid == -1) {
244 smb_enable_hw(drvdata);
246 drvdata->mode = CS_MODE_PERF;
252 static int smb_enable(struct coresight_device *csdev, enum cs_mode mode,
255 struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
258 spin_lock(&drvdata->spinlock);
260 /* Do nothing, the trace data is reading by other interface now */
261 if (drvdata->reading) {
266 /* Do nothing, the SMB is already enabled as other mode */
267 if (drvdata->mode != CS_MODE_DISABLED && drvdata->mode != mode) {
274 smb_enable_sysfs(csdev);
277 ret = smb_enable_perf(csdev, data);
286 atomic_inc(&csdev->refcnt);
288 dev_dbg(&csdev->dev, "Ultrasoc SMB enabled\n");
290 spin_unlock(&drvdata->spinlock);
295 static int smb_disable(struct coresight_device *csdev)
297 struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
300 spin_lock(&drvdata->spinlock);
302 if (drvdata->reading) {
307 if (atomic_dec_return(&csdev->refcnt)) {
312 /* Complain if we (somehow) got out of sync */
313 WARN_ON_ONCE(drvdata->mode == CS_MODE_DISABLED);
315 smb_disable_hw(drvdata);
317 /* Dissociate from the target process. */
319 drvdata->mode = CS_MODE_DISABLED;
321 dev_dbg(&csdev->dev, "Ultrasoc SMB disabled\n");
323 spin_unlock(&drvdata->spinlock);
328 static void *smb_alloc_buffer(struct coresight_device *csdev,
329 struct perf_event *event, void **pages,
330 int nr_pages, bool overwrite)
332 struct cs_buffers *buf;
335 node = (event->cpu == -1) ? NUMA_NO_NODE : cpu_to_node(event->cpu);
336 buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node);
340 buf->snapshot = overwrite;
341 buf->nr_pages = nr_pages;
342 buf->data_pages = pages;
343 buf->pid = task_pid_nr(event->owner);
348 static void smb_free_buffer(void *config)
350 struct cs_buffers *buf = config;
355 static void smb_sync_perf_buffer(struct smb_drv_data *drvdata,
356 struct cs_buffers *buf,
359 struct smb_data_buffer *sdb = &drvdata->sdb;
360 char **dst_pages = (char **)buf->data_pages;
361 unsigned long to_copy;
362 long pg_idx, pg_offset;
364 pg_idx = head >> PAGE_SHIFT;
365 pg_offset = head & (PAGE_SIZE - 1);
367 while (sdb->data_size) {
368 unsigned long pg_space = PAGE_SIZE - pg_offset;
370 to_copy = min(sdb->data_size, pg_space);
372 /* Copy parts of trace data when read pointer wrap around */
373 if (sdb->buf_rdptr + to_copy > sdb->buf_size)
374 to_copy = sdb->buf_size - sdb->buf_rdptr;
376 memcpy(dst_pages[pg_idx] + pg_offset,
377 sdb->buf_base + sdb->buf_rdptr, to_copy);
379 pg_offset += to_copy;
380 if (pg_offset >= PAGE_SIZE) {
383 pg_idx %= buf->nr_pages;
385 smb_update_read_ptr(drvdata, to_copy);
388 smb_reset_buffer(drvdata);
391 static unsigned long smb_update_buffer(struct coresight_device *csdev,
392 struct perf_output_handle *handle,
395 struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
396 struct smb_data_buffer *sdb = &drvdata->sdb;
397 struct cs_buffers *buf = sink_config;
398 unsigned long data_size = 0;
404 spin_lock(&drvdata->spinlock);
406 /* Don't do anything if another tracer is using this sink. */
407 if (atomic_read(&csdev->refcnt) != 1)
410 smb_disable_hw(drvdata);
411 smb_update_data_size(drvdata);
414 * The SMB buffer may be bigger than the space available in the
415 * perf ring buffer (handle->size). If so advance the offset so
416 * that we get the latest trace data.
418 if (sdb->data_size > handle->size) {
419 smb_update_read_ptr(drvdata, sdb->data_size - handle->size);
423 data_size = sdb->data_size;
424 smb_sync_perf_buffer(drvdata, buf, handle->head);
425 if (!buf->snapshot && lost)
426 perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
428 spin_unlock(&drvdata->spinlock);
433 static const struct coresight_ops_sink smb_cs_ops = {
434 .enable = smb_enable,
435 .disable = smb_disable,
436 .alloc_buffer = smb_alloc_buffer,
437 .free_buffer = smb_free_buffer,
438 .update_buffer = smb_update_buffer,
441 static const struct coresight_ops cs_ops = {
442 .sink_ops = &smb_cs_ops,
445 static int smb_init_data_buffer(struct platform_device *pdev,
446 struct smb_data_buffer *sdb)
448 struct resource *res;
451 res = platform_get_resource(pdev, IORESOURCE_MEM, SMB_BUF_ADDR_RES);
453 dev_err(&pdev->dev, "SMB device failed to get resource\n");
458 sdb->buf_hw_base = FIELD_GET(SMB_BUF_ADDR_LO_MSK, res->start);
459 sdb->buf_size = resource_size(res);
460 if (sdb->buf_size == 0)
464 * This is a chunk of memory, use classic mapping with better
467 base = devm_memremap(&pdev->dev, sdb->buf_hw_base, sdb->buf_size,
470 return PTR_ERR(base);
472 sdb->buf_base = base;
477 static void smb_init_hw(struct smb_drv_data *drvdata)
479 smb_disable_hw(drvdata);
481 writel(SMB_LB_CFG_LO_DEFAULT, drvdata->base + SMB_LB_CFG_LO_REG);
482 writel(SMB_LB_CFG_HI_DEFAULT, drvdata->base + SMB_LB_CFG_HI_REG);
483 writel(SMB_GLB_CFG_DEFAULT, drvdata->base + SMB_GLB_CFG_REG);
484 writel(SMB_GLB_INT_CFG, drvdata->base + SMB_GLB_INT_REG);
485 writel(SMB_LB_INT_CTRL_CFG, drvdata->base + SMB_LB_INT_CTRL_REG);
488 static int smb_register_sink(struct platform_device *pdev,
489 struct smb_drv_data *drvdata)
491 struct coresight_platform_data *pdata = NULL;
492 struct coresight_desc desc = { 0 };
495 pdata = coresight_get_platform_data(&pdev->dev);
497 return PTR_ERR(pdata);
499 desc.type = CORESIGHT_DEV_TYPE_SINK;
500 desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER;
503 desc.dev = &pdev->dev;
504 desc.groups = smb_sink_groups;
505 desc.name = coresight_alloc_device_name(&sink_devs, &pdev->dev);
507 dev_err(&pdev->dev, "Failed to alloc coresight device name");
510 desc.access = CSDEV_ACCESS_IOMEM(drvdata->base);
512 drvdata->csdev = coresight_register(&desc);
513 if (IS_ERR(drvdata->csdev))
514 return PTR_ERR(drvdata->csdev);
516 drvdata->miscdev.name = desc.name;
517 drvdata->miscdev.minor = MISC_DYNAMIC_MINOR;
518 drvdata->miscdev.fops = &smb_fops;
519 ret = misc_register(&drvdata->miscdev);
521 coresight_unregister(drvdata->csdev);
522 dev_err(&pdev->dev, "Failed to register misc, ret=%d\n", ret);
528 static void smb_unregister_sink(struct smb_drv_data *drvdata)
530 misc_deregister(&drvdata->miscdev);
531 coresight_unregister(drvdata->csdev);
534 static int smb_config_inport(struct device *dev, bool enable)
536 u64 func = enable ? 1 : 0;
537 union acpi_object *obj;
542 * Using DSM calls to enable/disable ultrasoc hardwares on
543 * tracing path, to prevent ultrasoc packet format being exposed.
545 if (guid_parse(ULTRASOC_SMB_DSM_UUID, &guid)) {
546 dev_err(dev, "Get GUID failed\n");
550 obj = acpi_evaluate_dsm(ACPI_HANDLE(dev), &guid, rev, func, NULL);
552 dev_err(dev, "ACPI handle failed\n");
561 static int smb_probe(struct platform_device *pdev)
563 struct device *dev = &pdev->dev;
564 struct smb_drv_data *drvdata;
567 drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
571 drvdata->base = devm_platform_ioremap_resource(pdev, SMB_REG_ADDR_RES);
572 if (IS_ERR(drvdata->base)) {
573 dev_err(dev, "Failed to ioremap resource\n");
574 return PTR_ERR(drvdata->base);
577 smb_init_hw(drvdata);
579 ret = smb_init_data_buffer(pdev, &drvdata->sdb);
581 dev_err(dev, "Failed to init buffer, ret = %d\n", ret);
585 ret = smb_config_inport(dev, true);
589 smb_reset_buffer(drvdata);
590 platform_set_drvdata(pdev, drvdata);
591 spin_lock_init(&drvdata->spinlock);
594 ret = smb_register_sink(pdev, drvdata);
596 smb_config_inport(&pdev->dev, false);
597 dev_err(dev, "Failed to register SMB sink\n");
604 static int smb_remove(struct platform_device *pdev)
606 struct smb_drv_data *drvdata = platform_get_drvdata(pdev);
608 smb_unregister_sink(drvdata);
610 smb_config_inport(&pdev->dev, false);
616 static const struct acpi_device_id ultrasoc_smb_acpi_match[] = {
620 MODULE_DEVICE_TABLE(acpi, ultrasoc_smb_acpi_match);
623 static struct platform_driver smb_driver = {
625 .name = "ultrasoc-smb",
626 .acpi_match_table = ACPI_PTR(ultrasoc_smb_acpi_match),
627 .suppress_bind_attrs = true,
630 .remove = smb_remove,
632 module_platform_driver(smb_driver);
634 MODULE_DESCRIPTION("UltraSoc SMB CoreSight driver");
635 MODULE_LICENSE("Dual MIT/GPL");
636 MODULE_AUTHOR("Jonathan Zhou <jonathan.zhouwen@huawei.com>");
637 MODULE_AUTHOR("Qi Liu <liuqi115@huawei.com>");