// SPDX-License-Identifier: GPL-2.0 /* * Copyright (c) 2011-2012, The Linux Foundation. All rights reserved. * * Description: CoreSight Embedded Trace Buffer driver */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "coresight-priv.h" #include "coresight-etm-perf.h" #define ETB_RAM_DEPTH_REG 0x004 #define ETB_STATUS_REG 0x00c #define ETB_RAM_READ_DATA_REG 0x010 #define ETB_RAM_READ_POINTER 0x014 #define ETB_RAM_WRITE_POINTER 0x018 #define ETB_TRG 0x01c #define ETB_CTL_REG 0x020 #define ETB_RWD_REG 0x024 #define ETB_FFSR 0x300 #define ETB_FFCR 0x304 #define ETB_ITMISCOP0 0xee0 #define ETB_ITTRFLINACK 0xee4 #define ETB_ITTRFLIN 0xee8 #define ETB_ITATBDATA0 0xeeC #define ETB_ITATBCTR2 0xef0 #define ETB_ITATBCTR1 0xef4 #define ETB_ITATBCTR0 0xef8 /* register description */ /* STS - 0x00C */ #define ETB_STATUS_RAM_FULL BIT(0) /* CTL - 0x020 */ #define ETB_CTL_CAPT_EN BIT(0) /* FFCR - 0x304 */ #define ETB_FFCR_EN_FTC BIT(0) #define ETB_FFCR_FON_MAN BIT(6) #define ETB_FFCR_STOP_FI BIT(12) #define ETB_FFCR_STOP_TRIGGER BIT(13) #define ETB_FFCR_BIT 6 #define ETB_FFSR_BIT 1 #define ETB_FRAME_SIZE_WORDS 4 DEFINE_CORESIGHT_DEVLIST(etb_devs, "etb"); /** * struct etb_drvdata - specifics associated to an ETB component * @base: memory mapped base address for this component. * @atclk: optional clock for the core parts of the ETB. * @csdev: component vitals needed by the framework. * @miscdev: specifics to handle "/dev/xyz.etb" entry. * @spinlock: only one at a time pls. * @reading: synchronise user space access to etb buffer. * @pid: Process ID of the process being monitored by the session * that is using this component. * @buf: area of memory where ETB buffer content gets sent. * @mode: this ETB is being used. * @buffer_depth: size of @buf. * @trigger_cntr: amount of words to store after a trigger. */ struct etb_drvdata { void __iomem *base; struct clk *atclk; struct coresight_device *csdev; struct miscdevice miscdev; spinlock_t spinlock; local_t reading; pid_t pid; u8 *buf; u32 mode; u32 buffer_depth; u32 trigger_cntr; }; static int etb_set_buffer(struct coresight_device *csdev, struct perf_output_handle *handle); static inline unsigned int etb_get_buffer_depth(struct etb_drvdata *drvdata) { return readl_relaxed(drvdata->base + ETB_RAM_DEPTH_REG); } static void __etb_enable_hw(struct etb_drvdata *drvdata) { int i; u32 depth; CS_UNLOCK(drvdata->base); depth = drvdata->buffer_depth; /* reset write RAM pointer address */ writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER); /* clear entire RAM buffer */ for (i = 0; i < depth; i++) writel_relaxed(0x0, drvdata->base + ETB_RWD_REG); /* reset write RAM pointer address */ writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER); /* reset read RAM pointer address */ writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER); writel_relaxed(drvdata->trigger_cntr, drvdata->base + ETB_TRG); writel_relaxed(ETB_FFCR_EN_FTC | ETB_FFCR_STOP_TRIGGER, drvdata->base + ETB_FFCR); /* ETB trace capture enable */ writel_relaxed(ETB_CTL_CAPT_EN, drvdata->base + ETB_CTL_REG); CS_LOCK(drvdata->base); } static int etb_enable_hw(struct etb_drvdata *drvdata) { int rc = coresight_claim_device(drvdata->base); if (rc) return rc; __etb_enable_hw(drvdata); return 0; } static int etb_enable_sysfs(struct coresight_device *csdev) { int ret = 0; unsigned long flags; struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); spin_lock_irqsave(&drvdata->spinlock, flags); /* Don't messup with perf sessions. */ if (drvdata->mode == CS_MODE_PERF) { ret = -EBUSY; goto out; } if (drvdata->mode == CS_MODE_DISABLED) { ret = etb_enable_hw(drvdata); if (ret) goto out; drvdata->mode = CS_MODE_SYSFS; } atomic_inc(csdev->refcnt); out: spin_unlock_irqrestore(&drvdata->spinlock, flags); return ret; } static int etb_enable_perf(struct coresight_device *csdev, void *data) { int ret = 0; pid_t pid; unsigned long flags; struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); struct perf_output_handle *handle = data; struct cs_buffers *buf = etm_perf_sink_config(handle); spin_lock_irqsave(&drvdata->spinlock, flags); /* No need to continue if the component is already in used by sysFS. */ if (drvdata->mode == CS_MODE_SYSFS) { ret = -EBUSY; goto out; } /* Get a handle on the pid of the process to monitor */ pid = buf->pid; if (drvdata->pid != -1 && drvdata->pid != pid) { ret = -EBUSY; goto out; } /* * No HW configuration is needed if the sink is already in * use for this session. */ if (drvdata->pid == pid) { atomic_inc(csdev->refcnt); goto out; } /* * We don't have an internal state to clean up if we fail to setup * the perf buffer. So we can perform the step before we turn the * ETB on and leave without cleaning up. */ ret = etb_set_buffer(csdev, handle); if (ret) goto out; ret = etb_enable_hw(drvdata); if (!ret) { /* Associate with monitored process. */ drvdata->pid = pid; drvdata->mode = CS_MODE_PERF; atomic_inc(csdev->refcnt); } out: spin_unlock_irqrestore(&drvdata->spinlock, flags); return ret; } static int etb_enable(struct coresight_device *csdev, u32 mode, void *data) { int ret; switch (mode) { case CS_MODE_SYSFS: ret = etb_enable_sysfs(csdev); break; case CS_MODE_PERF: ret = etb_enable_perf(csdev, data); break; default: ret = -EINVAL; break; } if (ret) return ret; dev_dbg(&csdev->dev, "ETB enabled\n"); return 0; } static void __etb_disable_hw(struct etb_drvdata *drvdata) { u32 ffcr; struct device *dev = &drvdata->csdev->dev; CS_UNLOCK(drvdata->base); ffcr = readl_relaxed(drvdata->base + ETB_FFCR); /* stop formatter when a stop has completed */ ffcr |= ETB_FFCR_STOP_FI; writel_relaxed(ffcr, drvdata->base + ETB_FFCR); /* manually generate a flush of the system */ ffcr |= ETB_FFCR_FON_MAN; writel_relaxed(ffcr, drvdata->base + ETB_FFCR); if (coresight_timeout(drvdata->base, ETB_FFCR, ETB_FFCR_BIT, 0)) { dev_err(dev, "timeout while waiting for completion of Manual Flush\n"); } /* disable trace capture */ writel_relaxed(0x0, drvdata->base + ETB_CTL_REG); if (coresight_timeout(drvdata->base, ETB_FFSR, ETB_FFSR_BIT, 1)) { dev_err(dev, "timeout while waiting for Formatter to Stop\n"); } CS_LOCK(drvdata->base); } static void etb_dump_hw(struct etb_drvdata *drvdata) { bool lost = false; int i; u8 *buf_ptr; u32 read_data, depth; u32 read_ptr, write_ptr; u32 frame_off, frame_endoff; struct device *dev = &drvdata->csdev->dev; CS_UNLOCK(drvdata->base); read_ptr = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER); write_ptr = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER); frame_off = write_ptr % ETB_FRAME_SIZE_WORDS; frame_endoff = ETB_FRAME_SIZE_WORDS - frame_off; if (frame_off) { dev_err(dev, "write_ptr: %lu not aligned to formatter frame size\n", (unsigned long)write_ptr); dev_err(dev, "frameoff: %lu, frame_endoff: %lu\n", (unsigned long)frame_off, (unsigned long)frame_endoff); write_ptr += frame_endoff; } if ((readl_relaxed(drvdata->base + ETB_STATUS_REG) & ETB_STATUS_RAM_FULL) == 0) { writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER); } else { writel_relaxed(write_ptr, drvdata->base + ETB_RAM_READ_POINTER); lost = true; } depth = drvdata->buffer_depth; buf_ptr = drvdata->buf; for (i = 0; i < depth; i++) { read_data = readl_relaxed(drvdata->base + ETB_RAM_READ_DATA_REG); *(u32 *)buf_ptr = read_data; buf_ptr += 4; } if (lost) coresight_insert_barrier_packet(drvdata->buf); if (frame_off) { buf_ptr -= (frame_endoff * 4); for (i = 0; i < frame_endoff; i++) { *buf_ptr++ = 0x0; *buf_ptr++ = 0x0; *buf_ptr++ = 0x0; *buf_ptr++ = 0x0; } } writel_relaxed(read_ptr, drvdata->base + ETB_RAM_READ_POINTER); CS_LOCK(drvdata->base); } static void etb_disable_hw(struct etb_drvdata *drvdata) { __etb_disable_hw(drvdata); etb_dump_hw(drvdata); coresight_disclaim_device(drvdata->base); } static int etb_disable(struct coresight_device *csdev) { struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); unsigned long flags; spin_lock_irqsave(&drvdata->spinlock, flags); if (atomic_dec_return(csdev->refcnt)) { spin_unlock_irqrestore(&drvdata->spinlock, flags); return -EBUSY; } /* Complain if we (somehow) got out of sync */ WARN_ON_ONCE(drvdata->mode == CS_MODE_DISABLED); etb_disable_hw(drvdata); /* Dissociate from monitored process. */ drvdata->pid = -1; drvdata->mode = CS_MODE_DISABLED; spin_unlock_irqrestore(&drvdata->spinlock, flags); dev_dbg(&csdev->dev, "ETB disabled\n"); return 0; } static void *etb_alloc_buffer(struct coresight_device *csdev, struct perf_event *event, void **pages, int nr_pages, bool overwrite) { int node; struct cs_buffers *buf; node = (event->cpu == -1) ? NUMA_NO_NODE : cpu_to_node(event->cpu); buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node); if (!buf) return NULL; buf->pid = task_pid_nr(event->owner); buf->snapshot = overwrite; buf->nr_pages = nr_pages; buf->data_pages = pages; return buf; } static void etb_free_buffer(void *config) { struct cs_buffers *buf = config; kfree(buf); } static int etb_set_buffer(struct coresight_device *csdev, struct perf_output_handle *handle) { int ret = 0; unsigned long head; struct cs_buffers *buf = etm_perf_sink_config(handle); if (!buf) return -EINVAL; /* wrap head around to the amount of space we have */ head = handle->head & ((buf->nr_pages << PAGE_SHIFT) - 1); /* find the page to write to */ buf->cur = head / PAGE_SIZE; /* and offset within that page */ buf->offset = head % PAGE_SIZE; local_set(&buf->data_size, 0); return ret; } static unsigned long etb_update_buffer(struct coresight_device *csdev, struct perf_output_handle *handle, void *sink_config) { bool lost = false; int i, cur; u8 *buf_ptr; const u32 *barrier; u32 read_ptr, write_ptr, capacity; u32 status, read_data; unsigned long offset, to_read = 0, flags; struct cs_buffers *buf = sink_config; struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); if (!buf) return 0; capacity = drvdata->buffer_depth * ETB_FRAME_SIZE_WORDS; spin_lock_irqsave(&drvdata->spinlock, flags); /* Don't do anything if another tracer is using this sink */ if (atomic_read(csdev->refcnt) != 1) goto out; __etb_disable_hw(drvdata); CS_UNLOCK(drvdata->base); /* unit is in words, not bytes */ read_ptr = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER); write_ptr = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER); /* * Entries should be aligned to the frame size. If they are not * go back to the last alignment point to give decoding tools a * chance to fix things. */ if (write_ptr % ETB_FRAME_SIZE_WORDS) { dev_err(&csdev->dev, "write_ptr: %lu not aligned to formatter frame size\n", (unsigned long)write_ptr); write_ptr &= ~(ETB_FRAME_SIZE_WORDS - 1); lost = true; } /* * Get a hold of the status register and see if a wrap around * has occurred. If so adjust things accordingly. Otherwise * start at the beginning and go until the write pointer has * been reached. */ status = readl_relaxed(drvdata->base + ETB_STATUS_REG); if (status & ETB_STATUS_RAM_FULL) { lost = true; to_read = capacity; read_ptr = write_ptr; } else { to_read = CIRC_CNT(write_ptr, read_ptr, drvdata->buffer_depth); to_read *= ETB_FRAME_SIZE_WORDS; } /* * Make sure we don't overwrite data that hasn't been consumed yet. * It is entirely possible that the HW buffer has more data than the * ring buffer can currently handle. If so adjust the start address * to take only the last traces. * * In snapshot mode we are looking to get the latest traces only and as * such, we don't care about not overwriting data that hasn't been * processed by user space. */ if (!buf->snapshot && to_read > handle->size) { u32 mask = ~(ETB_FRAME_SIZE_WORDS - 1); /* The new read pointer must be frame size aligned */ to_read = handle->size & mask; /* * Move the RAM read pointer up, keeping in mind that * everything is in frame size units. */ read_ptr = (write_ptr + drvdata->buffer_depth) - to_read / ETB_FRAME_SIZE_WORDS; /* Wrap around if need be*/ if (read_ptr > (drvdata->buffer_depth - 1)) read_ptr -= drvdata->buffer_depth; /* let the decoder know we've skipped ahead */ lost = true; } /* * Don't set the TRUNCATED flag in snapshot mode because 1) the * captured buffer is expected to be truncated and 2) a full buffer * prevents the event from being re-enabled by the perf core, * resulting in stale data being send to user space. */ if (!buf->snapshot && lost) perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED); /* finally tell HW where we want to start reading from */ writel_relaxed(read_ptr, drvdata->base + ETB_RAM_READ_POINTER); cur = buf->cur; offset = buf->offset; barrier = coresight_barrier_pkt; for (i = 0; i < to_read; i += 4) { buf_ptr = buf->data_pages[cur] + offset; read_data = readl_relaxed(drvdata->base + ETB_RAM_READ_DATA_REG); if (lost && i < CORESIGHT_BARRIER_PKT_SIZE) { read_data = *barrier; barrier++; } *(u32 *)buf_ptr = read_data; buf_ptr += 4; offset += 4; if (offset >= PAGE_SIZE) { offset = 0; cur++; /* wrap around at the end of the buffer */ cur &= buf->nr_pages - 1; } } /* reset ETB buffer for next run */ writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER); writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER); /* * In snapshot mode we simply increment the head by the number of byte * that were written. User space function cs_etm_find_snapshot() will * figure out how many bytes to get from the AUX buffer based on the * position of the head. */ if (buf->snapshot) handle->head += to_read; __etb_enable_hw(drvdata); CS_LOCK(drvdata->base); out: spin_unlock_irqrestore(&drvdata->spinlock, flags); return to_read; } static const struct coresight_ops_sink etb_sink_ops = { .enable = etb_enable, .disable = etb_disable, .alloc_buffer = etb_alloc_buffer, .free_buffer = etb_free_buffer, .update_buffer = etb_update_buffer, }; static const struct coresight_ops etb_cs_ops = { .sink_ops = &etb_sink_ops, }; static void etb_dump(struct etb_drvdata *drvdata) { unsigned long flags; spin_lock_irqsave(&drvdata->spinlock, flags); if (drvdata->mode == CS_MODE_SYSFS) { __etb_disable_hw(drvdata); etb_dump_hw(drvdata); __etb_enable_hw(drvdata); } spin_unlock_irqrestore(&drvdata->spinlock, flags); dev_dbg(&drvdata->csdev->dev, "ETB dumped\n"); } static int etb_open(struct inode *inode, struct file *file) { struct etb_drvdata *drvdata = container_of(file->private_data, struct etb_drvdata, miscdev); if (local_cmpxchg(&drvdata->reading, 0, 1)) return -EBUSY; dev_dbg(&drvdata->csdev->dev, "%s: successfully opened\n", __func__); return 0; } static ssize_t etb_read(struct file *file, char __user *data, size_t len, loff_t *ppos) { u32 depth; struct etb_drvdata *drvdata = container_of(file->private_data, struct etb_drvdata, miscdev); struct device *dev = &drvdata->csdev->dev; etb_dump(drvdata); depth = drvdata->buffer_depth; if (*ppos + len > depth * 4) len = depth * 4 - *ppos; if (copy_to_user(data, drvdata->buf + *ppos, len)) { dev_dbg(dev, "%s: copy_to_user failed\n", __func__); return -EFAULT; } *ppos += len; dev_dbg(dev, "%s: %zu bytes copied, %d bytes left\n", __func__, len, (int)(depth * 4 - *ppos)); return len; } static int etb_release(struct inode *inode, struct file *file) { struct etb_drvdata *drvdata = container_of(file->private_data, struct etb_drvdata, miscdev); local_set(&drvdata->reading, 0); dev_dbg(&drvdata->csdev->dev, "%s: released\n", __func__); return 0; } static const struct file_operations etb_fops = { .owner = THIS_MODULE, .open = etb_open, .read = etb_read, .release = etb_release, .llseek = no_llseek, }; #define coresight_etb10_reg(name, offset) \ coresight_simple_reg32(struct etb_drvdata, name, offset) coresight_etb10_reg(rdp, ETB_RAM_DEPTH_REG); coresight_etb10_reg(sts, ETB_STATUS_REG); coresight_etb10_reg(rrp, ETB_RAM_READ_POINTER); coresight_etb10_reg(rwp, ETB_RAM_WRITE_POINTER); coresight_etb10_reg(trg, ETB_TRG); coresight_etb10_reg(ctl, ETB_CTL_REG); coresight_etb10_reg(ffsr, ETB_FFSR); coresight_etb10_reg(ffcr, ETB_FFCR); static struct attribute *coresight_etb_mgmt_attrs[] = { &dev_attr_rdp.attr, &dev_attr_sts.attr, &dev_attr_rrp.attr, &dev_attr_rwp.attr, &dev_attr_trg.attr, &dev_attr_ctl.attr, &dev_attr_ffsr.attr, &dev_attr_ffcr.attr, NULL, }; static ssize_t trigger_cntr_show(struct device *dev, struct device_attribute *attr, char *buf) { struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent); unsigned long val = drvdata->trigger_cntr; return sprintf(buf, "%#lx\n", val); } static ssize_t trigger_cntr_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t size) { int ret; unsigned long val; struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent); ret = kstrtoul(buf, 16, &val); if (ret) return ret; drvdata->trigger_cntr = val; return size; } static DEVICE_ATTR_RW(trigger_cntr); static struct attribute *coresight_etb_attrs[] = { &dev_attr_trigger_cntr.attr, NULL, }; static const struct attribute_group coresight_etb_group = { .attrs = coresight_etb_attrs, }; static const struct attribute_group coresight_etb_mgmt_group = { .attrs = coresight_etb_mgmt_attrs, .name = "mgmt", }; static const struct attribute_group *coresight_etb_groups[] = { &coresight_etb_group, &coresight_etb_mgmt_group, NULL, }; static int etb_probe(struct amba_device *adev, const struct amba_id *id) { int ret; void __iomem *base; struct device *dev = &adev->dev; struct coresight_platform_data *pdata = NULL; struct etb_drvdata *drvdata; struct resource *res = &adev->res; struct coresight_desc desc = { 0 }; desc.name = coresight_alloc_device_name(&etb_devs, dev); if (!desc.name) return -ENOMEM; drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL); if (!drvdata) return -ENOMEM; drvdata->atclk = devm_clk_get(&adev->dev, "atclk"); /* optional */ if (!IS_ERR(drvdata->atclk)) { ret = clk_prepare_enable(drvdata->atclk); if (ret) return ret; } dev_set_drvdata(dev, drvdata); /* validity for the resource is already checked by the AMBA core */ base = devm_ioremap_resource(dev, res); if (IS_ERR(base)) return PTR_ERR(base); drvdata->base = base; desc.access = CSDEV_ACCESS_IOMEM(base); spin_lock_init(&drvdata->spinlock); drvdata->buffer_depth = etb_get_buffer_depth(drvdata); if (drvdata->buffer_depth & 0x80000000) return -EINVAL; drvdata->buf = devm_kcalloc(dev, drvdata->buffer_depth, 4, GFP_KERNEL); if (!drvdata->buf) return -ENOMEM; /* This device is not associated with a session */ drvdata->pid = -1; pdata = coresight_get_platform_data(dev); if (IS_ERR(pdata)) return PTR_ERR(pdata); adev->dev.platform_data = pdata; desc.type = CORESIGHT_DEV_TYPE_SINK; desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER; desc.ops = &etb_cs_ops; desc.pdata = pdata; desc.dev = dev; desc.groups = coresight_etb_groups; drvdata->csdev = coresight_register(&desc); if (IS_ERR(drvdata->csdev)) return PTR_ERR(drvdata->csdev); drvdata->miscdev.name = desc.name; drvdata->miscdev.minor = MISC_DYNAMIC_MINOR; drvdata->miscdev.fops = &etb_fops; ret = misc_register(&drvdata->miscdev); if (ret) goto err_misc_register; pm_runtime_put(&adev->dev); return 0; err_misc_register: coresight_unregister(drvdata->csdev); return ret; } static int etb_remove(struct amba_device *adev) { struct etb_drvdata *drvdata = dev_get_drvdata(&adev->dev); /* * Since misc_open() holds a refcount on the f_ops, which is * etb fops in this case, device is there until last file * handler to this device is closed. */ misc_deregister(&drvdata->miscdev); coresight_unregister(drvdata->csdev); return 0; } #ifdef CONFIG_PM static int etb_runtime_suspend(struct device *dev) { struct etb_drvdata *drvdata = dev_get_drvdata(dev); if (drvdata && !IS_ERR(drvdata->atclk)) clk_disable_unprepare(drvdata->atclk); return 0; } static int etb_runtime_resume(struct device *dev) { struct etb_drvdata *drvdata = dev_get_drvdata(dev); if (drvdata && !IS_ERR(drvdata->atclk)) clk_prepare_enable(drvdata->atclk); return 0; } #endif static const struct dev_pm_ops etb_dev_pm_ops = { SET_RUNTIME_PM_OPS(etb_runtime_suspend, etb_runtime_resume, NULL) }; static const struct amba_id etb_ids[] = { { .id = 0x000bb907, .mask = 0x000fffff, }, { 0, 0}, }; MODULE_DEVICE_TABLE(amba, etb_ids); static struct amba_driver etb_driver = { .drv = { .name = "coresight-etb10", .owner = THIS_MODULE, .pm = &etb_dev_pm_ops, .suppress_bind_attrs = true, }, .probe = etb_probe, .remove = etb_remove, .id_table = etb_ids, }; module_amba_driver(etb_driver); MODULE_AUTHOR("Pratik Patel "); MODULE_AUTHOR("Mathieu Poirier "); MODULE_DESCRIPTION("Arm CoreSight Embedded Trace Buffer driver"); MODULE_LICENSE("GPL v2");