1 files changed, 648 insertions, 0 deletions
diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.c b/drivers/hwtracing/coresight/ultrasoc-smb.c
new file mode 100644
index 000000000000..b317342c7ce5
--- /dev/null
+++ b/drivers/hwtracing/coresight/ultrasoc-smb.c
@@ -0,0 +1,648 @@
+// 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>");