| // SPDX-License-Identifier: (GPL-2.0 OR MIT) |
| /* |
| * Siemens System Memory Buffer driver. |
| * Copyright(c) 2022, HiSilicon Limited. |
| */ |
| |
| #include <linux/atomic.h> |
| #include <linux/acpi.h> |
| #include <linux/circ_buf.h> |
| #include <linux/err.h> |
| #include <linux/fs.h> |
| #include <linux/module.h> |
| #include <linux/mod_devicetable.h> |
| #include <linux/platform_device.h> |
| |
| #include "coresight-etm-perf.h" |
| #include "coresight-priv.h" |
| #include "ultrasoc-smb.h" |
| |
| DEFINE_CORESIGHT_DEVLIST(sink_devs, "ultra_smb"); |
| |
| #define ULTRASOC_SMB_DSM_UUID "82ae1283-7f6a-4cbe-aa06-53e8fb24db18" |
| |
| static bool smb_buffer_not_empty(struct smb_drv_data *drvdata) |
| { |
| u32 buf_status = readl(drvdata->base + SMB_LB_INT_STS_REG); |
| |
| return FIELD_GET(SMB_LB_INT_STS_NOT_EMPTY_MSK, buf_status); |
| } |
| |
| static void smb_update_data_size(struct smb_drv_data *drvdata) |
| { |
| struct smb_data_buffer *sdb = &drvdata->sdb; |
| u32 buf_wrptr; |
| |
| buf_wrptr = readl(drvdata->base + SMB_LB_WR_ADDR_REG) - |
| sdb->buf_hw_base; |
| |
| /* Buffer is full */ |
| if (buf_wrptr == sdb->buf_rdptr && smb_buffer_not_empty(drvdata)) { |
| sdb->data_size = sdb->buf_size; |
| return; |
| } |
| |
| /* The buffer mode is circular buffer mode */ |
| sdb->data_size = CIRC_CNT(buf_wrptr, sdb->buf_rdptr, |
| sdb->buf_size); |
| } |
| |
| /* |
| * The read pointer adds @nbytes bytes (may round up to the beginning) |
| * after the data is read or discarded, while needing to update the |
| * available data size. |
| */ |
| static void smb_update_read_ptr(struct smb_drv_data *drvdata, u32 nbytes) |
| { |
| struct smb_data_buffer *sdb = &drvdata->sdb; |
| |
| sdb->buf_rdptr += nbytes; |
| sdb->buf_rdptr %= sdb->buf_size; |
| writel(sdb->buf_hw_base + sdb->buf_rdptr, |
| drvdata->base + SMB_LB_RD_ADDR_REG); |
| |
| sdb->data_size -= nbytes; |
| } |
| |
| static void smb_reset_buffer(struct smb_drv_data *drvdata) |
| { |
| struct smb_data_buffer *sdb = &drvdata->sdb; |
| u32 write_ptr; |
| |
| /* |
| * We must flush and discard any data left in hardware path |
| * to avoid corrupting the next session. |
| * Note: The write pointer will never exceed the read pointer. |
| */ |
| writel(SMB_LB_PURGE_PURGED, drvdata->base + SMB_LB_PURGE_REG); |
| |
| /* Reset SMB logical buffer status flags */ |
| writel(SMB_LB_INT_STS_RESET, drvdata->base + SMB_LB_INT_STS_REG); |
| |
| write_ptr = readl(drvdata->base + SMB_LB_WR_ADDR_REG); |
| |
| /* Do nothing, not data left in hardware path */ |
| if (!write_ptr || write_ptr == sdb->buf_rdptr + sdb->buf_hw_base) |
| return; |
| |
| /* |
| * The SMB_LB_WR_ADDR_REG register is read-only, |
| * Synchronize the read pointer to write pointer. |
| */ |
| writel(write_ptr, drvdata->base + SMB_LB_RD_ADDR_REG); |
| sdb->buf_rdptr = write_ptr - sdb->buf_hw_base; |
| } |
| |
| static int smb_open(struct inode *inode, struct file *file) |
| { |
| struct smb_drv_data *drvdata = container_of(file->private_data, |
| struct smb_drv_data, miscdev); |
| int ret = 0; |
| |
| mutex_lock(&drvdata->mutex); |
| |
| if (drvdata->reading) { |
| ret = -EBUSY; |
| goto out; |
| } |
| |
| if (atomic_read(drvdata->csdev->refcnt)) { |
| ret = -EBUSY; |
| goto out; |
| } |
| |
| smb_update_data_size(drvdata); |
| |
| drvdata->reading = true; |
| out: |
| mutex_unlock(&drvdata->mutex); |
| |
| return ret; |
| } |
| |
| static ssize_t smb_read(struct file *file, char __user *data, size_t len, |
| loff_t *ppos) |
| { |
| struct smb_drv_data *drvdata = container_of(file->private_data, |
| struct smb_drv_data, miscdev); |
| struct smb_data_buffer *sdb = &drvdata->sdb; |
| struct device *dev = &drvdata->csdev->dev; |
| ssize_t to_copy = 0; |
| |
| if (!len) |
| return 0; |
| |
| mutex_lock(&drvdata->mutex); |
| |
| if (!sdb->data_size) |
| goto out; |
| |
| to_copy = min(sdb->data_size, len); |
| |
| /* Copy parts of trace data when read pointer wrap around SMB buffer */ |
| if (sdb->buf_rdptr + to_copy > sdb->buf_size) |
| to_copy = sdb->buf_size - sdb->buf_rdptr; |
| |
| if (copy_to_user(data, sdb->buf_base + sdb->buf_rdptr, to_copy)) { |
| dev_dbg(dev, "Failed to copy data to user\n"); |
| to_copy = -EFAULT; |
| goto out; |
| } |
| |
| *ppos += to_copy; |
| |
| smb_update_read_ptr(drvdata, to_copy); |
| |
| dev_dbg(dev, "%zu bytes copied\n", to_copy); |
| out: |
| if (!sdb->data_size) |
| smb_reset_buffer(drvdata); |
| mutex_unlock(&drvdata->mutex); |
| |
| return to_copy; |
| } |
| |
| static int smb_release(struct inode *inode, struct file *file) |
| { |
| struct smb_drv_data *drvdata = container_of(file->private_data, |
| struct smb_drv_data, miscdev); |
| |
| mutex_lock(&drvdata->mutex); |
| drvdata->reading = false; |
| mutex_unlock(&drvdata->mutex); |
| |
| return 0; |
| } |
| |
| static const struct file_operations smb_fops = { |
| .owner = THIS_MODULE, |
| .open = smb_open, |
| .read = smb_read, |
| .release = smb_release, |
| .llseek = no_llseek, |
| }; |
| |
| static ssize_t buf_size_show(struct device *dev, struct device_attribute *attr, |
| char *buf) |
| { |
| struct smb_drv_data *drvdata = dev_get_drvdata(dev->parent); |
| |
| return sysfs_emit(buf, "0x%lx\n", drvdata->sdb.buf_size); |
| } |
| static DEVICE_ATTR_RO(buf_size); |
| |
| static struct attribute *smb_sink_attrs[] = { |
| coresight_simple_reg32(read_pos, SMB_LB_RD_ADDR_REG), |
| coresight_simple_reg32(write_pos, SMB_LB_WR_ADDR_REG), |
| coresight_simple_reg32(buf_status, SMB_LB_INT_STS_REG), |
| &dev_attr_buf_size.attr, |
| NULL |
| }; |
| |
| static const struct attribute_group smb_sink_group = { |
| .attrs = smb_sink_attrs, |
| .name = "mgmt", |
| }; |
| |
| static const struct attribute_group *smb_sink_groups[] = { |
| &smb_sink_group, |
| NULL |
| }; |
| |
| static void smb_enable_hw(struct smb_drv_data *drvdata) |
| { |
| writel(SMB_GLB_EN_HW_ENABLE, drvdata->base + SMB_GLB_EN_REG); |
| } |
| |
| static void smb_disable_hw(struct smb_drv_data *drvdata) |
| { |
| writel(0x0, drvdata->base + SMB_GLB_EN_REG); |
| } |
| |
| static void smb_enable_sysfs(struct coresight_device *csdev) |
| { |
| struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); |
| |
| if (drvdata->mode != CS_MODE_DISABLED) |
| return; |
| |
| smb_enable_hw(drvdata); |
| drvdata->mode = CS_MODE_SYSFS; |
| } |
| |
| static int smb_enable_perf(struct coresight_device *csdev, void *data) |
| { |
| struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); |
| struct perf_output_handle *handle = data; |
| struct cs_buffers *buf = etm_perf_sink_config(handle); |
| pid_t pid; |
| |
| if (!buf) |
| return -EINVAL; |
| |
| /* Get a handle on the pid of the target process */ |
| pid = buf->pid; |
| |
| /* Device is already in used by other session */ |
| if (drvdata->pid != -1 && drvdata->pid != pid) |
| return -EBUSY; |
| |
| if (drvdata->pid == -1) { |
| smb_enable_hw(drvdata); |
| drvdata->pid = pid; |
| drvdata->mode = CS_MODE_PERF; |
| } |
| |
| return 0; |
| } |
| |
| static int smb_enable(struct coresight_device *csdev, u32 mode, void *data) |
| { |
| struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); |
| int ret = 0; |
| |
| mutex_lock(&drvdata->mutex); |
| |
| /* Do nothing, the trace data is reading by other interface now */ |
| if (drvdata->reading) { |
| ret = -EBUSY; |
| goto out; |
| } |
| |
| /* Do nothing, the SMB is already enabled as other mode */ |
| if (drvdata->mode != CS_MODE_DISABLED && drvdata->mode != mode) { |
| ret = -EBUSY; |
| goto out; |
| } |
| |
| switch (mode) { |
| case CS_MODE_SYSFS: |
| smb_enable_sysfs(csdev); |
| break; |
| case CS_MODE_PERF: |
| ret = smb_enable_perf(csdev, data); |
| break; |
| default: |
| ret = -EINVAL; |
| } |
| |
| if (ret) |
| goto out; |
| |
| atomic_inc(csdev->refcnt); |
| |
| dev_dbg(&csdev->dev, "Ultrasoc SMB enabled\n"); |
| out: |
| mutex_unlock(&drvdata->mutex); |
| |
| return ret; |
| } |
| |
| static int smb_disable(struct coresight_device *csdev) |
| { |
| struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); |
| int ret = 0; |
| |
| mutex_lock(&drvdata->mutex); |
| |
| if (drvdata->reading) { |
| ret = -EBUSY; |
| goto out; |
| } |
| |
| if (atomic_dec_return(csdev->refcnt)) { |
| ret = -EBUSY; |
| goto out; |
| } |
| |
| /* Complain if we (somehow) got out of sync */ |
| WARN_ON_ONCE(drvdata->mode == CS_MODE_DISABLED); |
| |
| smb_disable_hw(drvdata); |
| |
| /* Dissociate from the target process. */ |
| drvdata->pid = -1; |
| drvdata->mode = CS_MODE_DISABLED; |
| |
| dev_dbg(&csdev->dev, "Ultrasoc SMB disabled\n"); |
| out: |
| mutex_unlock(&drvdata->mutex); |
| |
| return ret; |
| } |
| |
| static void *smb_alloc_buffer(struct coresight_device *csdev, |
| struct perf_event *event, void **pages, |
| int nr_pages, bool overwrite) |
| { |
| struct cs_buffers *buf; |
| int node; |
| |
| 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->snapshot = overwrite; |
| buf->nr_pages = nr_pages; |
| buf->data_pages = pages; |
| buf->pid = task_pid_nr(event->owner); |
| |
| return buf; |
| } |
| |
| static void smb_free_buffer(void *config) |
| { |
| struct cs_buffers *buf = config; |
| |
| kfree(buf); |
| } |
| |
| static void smb_sync_perf_buffer(struct smb_drv_data *drvdata, |
| struct cs_buffers *buf, |
| unsigned long head) |
| { |
| struct smb_data_buffer *sdb = &drvdata->sdb; |
| char **dst_pages = (char **)buf->data_pages; |
| unsigned long to_copy; |
| long pg_idx, pg_offset; |
| |
| pg_idx = head >> PAGE_SHIFT; |
| pg_offset = head & (PAGE_SIZE - 1); |
| |
| while (sdb->data_size) { |
| unsigned long pg_space = PAGE_SIZE - pg_offset; |
| |
| to_copy = min(sdb->data_size, pg_space); |
| |
| /* Copy parts of trace data when read pointer wrap around */ |
| if (sdb->buf_rdptr + to_copy > sdb->buf_size) |
| to_copy = sdb->buf_size - sdb->buf_rdptr; |
| |
| memcpy(dst_pages[pg_idx] + pg_offset, |
| sdb->buf_base + sdb->buf_rdptr, to_copy); |
| |
| pg_offset += to_copy; |
| if (pg_offset >= PAGE_SIZE) { |
| pg_offset = 0; |
| pg_idx++; |
| pg_idx %= buf->nr_pages; |
| } |
| smb_update_read_ptr(drvdata, to_copy); |
| } |
| |
| smb_reset_buffer(drvdata); |
| } |
| |
| static unsigned long smb_update_buffer(struct coresight_device *csdev, |
| struct perf_output_handle *handle, |
| void *sink_config) |
| { |
| struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); |
| struct smb_data_buffer *sdb = &drvdata->sdb; |
| struct cs_buffers *buf = sink_config; |
| unsigned long data_size = 0; |
| bool lost = false; |
| |
| if (!buf) |
| return 0; |
| |
| mutex_lock(&drvdata->mutex); |
| |
| /* Don't do anything if another tracer is using this sink. */ |
| if (atomic_read(csdev->refcnt) != 1) |
| goto out; |
| |
| smb_disable_hw(drvdata); |
| smb_update_data_size(drvdata); |
| |
| /* |
| * The SMB buffer may be bigger than the space available in the |
| * perf ring buffer (handle->size). If so advance the offset so |
| * that we get the latest trace data. |
| */ |
| if (sdb->data_size > handle->size) { |
| smb_update_read_ptr(drvdata, sdb->data_size - handle->size); |
| lost = true; |
| } |
| |
| data_size = sdb->data_size; |
| smb_sync_perf_buffer(drvdata, buf, handle->head); |
| if (!buf->snapshot && lost) |
| perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED); |
| out: |
| mutex_unlock(&drvdata->mutex); |
| |
| return data_size; |
| } |
| |
| static const struct coresight_ops_sink smb_cs_ops = { |
| .enable = smb_enable, |
| .disable = smb_disable, |
| .alloc_buffer = smb_alloc_buffer, |
| .free_buffer = smb_free_buffer, |
| .update_buffer = smb_update_buffer, |
| }; |
| |
| static const struct coresight_ops cs_ops = { |
| .sink_ops = &smb_cs_ops, |
| }; |
| |
| static int smb_init_data_buffer(struct platform_device *pdev, |
| struct smb_data_buffer *sdb) |
| { |
| struct resource *res; |
| void *base; |
| |
| res = platform_get_resource(pdev, IORESOURCE_MEM, SMB_BUF_ADDR_RES); |
| if (!res) { |
| dev_err(&pdev->dev, "SMB device failed to get resource\n"); |
| return -EINVAL; |
| } |
| |
| sdb->buf_rdptr = 0; |
| sdb->buf_hw_base = FIELD_GET(SMB_BUF_ADDR_LO_MSK, res->start); |
| sdb->buf_size = resource_size(res); |
| if (sdb->buf_size == 0) |
| return -EINVAL; |
| |
| /* |
| * This is a chunk of memory, use classic mapping with better |
| * performance. |
| */ |
| base = devm_memremap(&pdev->dev, sdb->buf_hw_base, sdb->buf_size, |
| MEMREMAP_WB); |
| if (IS_ERR(base)) |
| return PTR_ERR(base); |
| |
| sdb->buf_base = base; |
| |
| return 0; |
| } |
| |
| static void smb_init_hw(struct smb_drv_data *drvdata) |
| { |
| smb_disable_hw(drvdata); |
| smb_reset_buffer(drvdata); |
| |
| writel(SMB_LB_CFG_LO_DEFAULT, drvdata->base + SMB_LB_CFG_LO_REG); |
| writel(SMB_LB_CFG_HI_DEFAULT, drvdata->base + SMB_LB_CFG_HI_REG); |
| writel(SMB_GLB_CFG_DEFAULT, drvdata->base + SMB_GLB_CFG_REG); |
| writel(SMB_GLB_INT_CFG, drvdata->base + SMB_GLB_INT_REG); |
| writel(SMB_LB_INT_CTRL_CFG, drvdata->base + SMB_LB_INT_CTRL_REG); |
| } |
| |
| static int smb_register_sink(struct platform_device *pdev, |
| struct smb_drv_data *drvdata) |
| { |
| struct coresight_platform_data *pdata = NULL; |
| struct coresight_desc desc = { 0 }; |
| int ret; |
| |
| pdata = coresight_get_platform_data(&pdev->dev); |
| if (IS_ERR(pdata)) |
| return PTR_ERR(pdata); |
| |
| desc.type = CORESIGHT_DEV_TYPE_SINK; |
| desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER; |
| desc.ops = &cs_ops; |
| desc.pdata = pdata; |
| desc.dev = &pdev->dev; |
| desc.groups = smb_sink_groups; |
| desc.name = coresight_alloc_device_name(&sink_devs, &pdev->dev); |
| if (!desc.name) { |
| dev_err(&pdev->dev, "Failed to alloc coresight device name"); |
| return -ENOMEM; |
| } |
| desc.access = CSDEV_ACCESS_IOMEM(drvdata->base); |
| |
| 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 = &smb_fops; |
| ret = misc_register(&drvdata->miscdev); |
| if (ret) { |
| coresight_unregister(drvdata->csdev); |
| dev_err(&pdev->dev, "Failed to register misc, ret=%d\n", ret); |
| } |
| |
| return ret; |
| } |
| |
| static void smb_unregister_sink(struct smb_drv_data *drvdata) |
| { |
| misc_deregister(&drvdata->miscdev); |
| coresight_unregister(drvdata->csdev); |
| } |
| |
| static int smb_config_inport(struct device *dev, bool enable) |
| { |
| u64 func = enable ? 1 : 0; |
| union acpi_object *obj; |
| guid_t guid; |
| u64 rev = 0; |
| |
| /* |
| * Using DSM calls to enable/disable ultrasoc hardwares on |
| * tracing path, to prevent ultrasoc packet format being exposed. |
| */ |
| if (guid_parse(ULTRASOC_SMB_DSM_UUID, &guid)) { |
| dev_err(dev, "Get GUID failed\n"); |
| return -EINVAL; |
| } |
| |
| obj = acpi_evaluate_dsm(ACPI_HANDLE(dev), &guid, rev, func, NULL); |
| if (!obj) { |
| dev_err(dev, "ACPI handle failed\n"); |
| return -ENODEV; |
| } |
| |
| ACPI_FREE(obj); |
| |
| return 0; |
| } |
| |
| static int smb_probe(struct platform_device *pdev) |
| { |
| struct device *dev = &pdev->dev; |
| struct smb_drv_data *drvdata; |
| int ret; |
| |
| drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL); |
| if (!drvdata) |
| return -ENOMEM; |
| |
| drvdata->base = devm_platform_ioremap_resource(pdev, SMB_REG_ADDR_RES); |
| if (IS_ERR(drvdata->base)) { |
| dev_err(dev, "Failed to ioremap resource\n"); |
| return PTR_ERR(drvdata->base); |
| } |
| |
| smb_init_hw(drvdata); |
| |
| ret = smb_init_data_buffer(pdev, &drvdata->sdb); |
| if (ret) { |
| dev_err(dev, "Failed to init buffer, ret = %d\n", ret); |
| return ret; |
| } |
| |
| mutex_init(&drvdata->mutex); |
| drvdata->pid = -1; |
| |
| ret = smb_register_sink(pdev, drvdata); |
| if (ret) { |
| dev_err(dev, "Failed to register SMB sink\n"); |
| return ret; |
| } |
| |
| ret = smb_config_inport(dev, true); |
| if (ret) { |
| smb_unregister_sink(drvdata); |
| return ret; |
| } |
| |
| platform_set_drvdata(pdev, drvdata); |
| |
| return 0; |
| } |
| |
| static int smb_remove(struct platform_device *pdev) |
| { |
| struct smb_drv_data *drvdata = platform_get_drvdata(pdev); |
| int ret; |
| |
| ret = smb_config_inport(&pdev->dev, false); |
| if (ret) |
| return ret; |
| |
| smb_unregister_sink(drvdata); |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_ACPI |
| static const struct acpi_device_id ultrasoc_smb_acpi_match[] = { |
| {"HISI03A1", 0}, |
| {} |
| }; |
| MODULE_DEVICE_TABLE(acpi, ultrasoc_smb_acpi_match); |
| #endif |
| |
| static struct platform_driver smb_driver = { |
| .driver = { |
| .name = "ultrasoc-smb", |
| .acpi_match_table = ACPI_PTR(ultrasoc_smb_acpi_match), |
| .suppress_bind_attrs = true, |
| }, |
| .probe = smb_probe, |
| .remove = smb_remove, |
| }; |
| module_platform_driver(smb_driver); |
| |
| MODULE_DESCRIPTION("UltraSoc SMB CoreSight driver"); |
| MODULE_LICENSE("Dual MIT/GPL"); |
| MODULE_AUTHOR("Jonathan Zhou <jonathan.zhouwen@huawei.com>"); |
| MODULE_AUTHOR("Qi Liu <liuqi115@huawei.com>"); |