From f70575805708cabdedea7498aaa3f710fde4d920 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Wed, 31 Jan 2024 03:29:01 +0000
Subject: [PATCH] add lvds1024*800

---
 kernel/drivers/hwtracing/coresight/coresight-etb10.c |  165 +++++++++++++++++++++++++++++++++++++------------------
 1 files changed, 111 insertions(+), 54 deletions(-)

diff --git a/kernel/drivers/hwtracing/coresight/coresight-etb10.c b/kernel/drivers/hwtracing/coresight/coresight-etb10.c
index f6afee0..f775cbe 100644
--- a/kernel/drivers/hwtracing/coresight/coresight-etb10.c
+++ b/kernel/drivers/hwtracing/coresight/coresight-etb10.c
@@ -63,15 +63,18 @@
 #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.
- * @dev:	the device entity associated to 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.
@@ -79,12 +82,12 @@
  */
 struct etb_drvdata {
 	void __iomem		*base;
-	struct device		*dev;
 	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;
@@ -94,17 +97,9 @@
 static int etb_set_buffer(struct coresight_device *csdev,
 			  struct perf_output_handle *handle);
 
-static unsigned int etb_get_buffer_depth(struct etb_drvdata *drvdata)
+static inline unsigned int etb_get_buffer_depth(struct etb_drvdata *drvdata)
 {
-	u32 depth = 0;
-
-	pm_runtime_get_sync(drvdata->dev);
-
-	/* RO registers don't need locking */
-	depth = readl_relaxed(drvdata->base + ETB_RAM_DEPTH_REG);
-
-	pm_runtime_put(drvdata->dev);
-	return depth;
+	return readl_relaxed(drvdata->base + ETB_RAM_DEPTH_REG);
 }
 
 static void __etb_enable_hw(struct etb_drvdata *drvdata)
@@ -137,7 +132,7 @@
 
 static int etb_enable_hw(struct etb_drvdata *drvdata)
 {
-	int rc = coresight_claim_device(drvdata->base);
+	int rc = coresight_claim_device(drvdata->csdev);
 
 	if (rc)
 		return rc;
@@ -177,14 +172,34 @@
 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 use. */
-	if (drvdata->mode != CS_MODE_DISABLED) {
+	/* 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;
 	}
 
@@ -193,12 +208,14 @@
 	 * 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, (struct perf_output_handle *)data);
+	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);
 	}
@@ -211,7 +228,6 @@
 static int etb_enable(struct coresight_device *csdev, u32 mode, void *data)
 {
 	int ret;
-	struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
 
 	switch (mode) {
 	case CS_MODE_SYSFS:
@@ -228,13 +244,15 @@
 	if (ret)
 		return ret;
 
-	dev_dbg(drvdata->dev, "ETB enabled\n");
+	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;
+	struct csdev_access *csa = &drvdata->csdev->access;
 
 	CS_UNLOCK(drvdata->base);
 
@@ -246,16 +264,16 @@
 	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(drvdata->dev,
+	if (coresight_timeout(csa, 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(drvdata->dev,
+	if (coresight_timeout(csa, ETB_FFSR, ETB_FFSR_BIT, 1)) {
+		dev_err(dev,
 			"timeout while waiting for Formatter to Stop\n");
 	}
 
@@ -270,6 +288,7 @@
 	u32 read_data, depth;
 	u32 read_ptr, write_ptr;
 	u32 frame_off, frame_endoff;
+	struct device *dev = &drvdata->csdev->dev;
 
 	CS_UNLOCK(drvdata->base);
 
@@ -279,10 +298,10 @@
 	frame_off = write_ptr % ETB_FRAME_SIZE_WORDS;
 	frame_endoff = ETB_FRAME_SIZE_WORDS - frame_off;
 	if (frame_off) {
-		dev_err(drvdata->dev,
+		dev_err(dev,
 			"write_ptr: %lu not aligned to formatter frame size\n",
 			(unsigned long)write_ptr);
-		dev_err(drvdata->dev, "frameoff: %lu, frame_endoff: %lu\n",
+		dev_err(dev, "frameoff: %lu, frame_endoff: %lu\n",
 			(unsigned long)frame_off, (unsigned long)frame_endoff);
 		write_ptr += frame_endoff;
 	}
@@ -326,7 +345,7 @@
 {
 	__etb_disable_hw(drvdata);
 	etb_dump_hw(drvdata);
-	coresight_disclaim_device(drvdata->base);
+	coresight_disclaim_device(drvdata->csdev);
 }
 
 static int etb_disable(struct coresight_device *csdev)
@@ -344,10 +363,12 @@
 	/* 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(drvdata->dev, "ETB disabled\n");
+	dev_dbg(&csdev->dev, "ETB disabled\n");
 	return 0;
 }
 
@@ -355,15 +376,16 @@
 			      struct perf_event *event, void **pages,
 			      int nr_pages, bool overwrite)
 {
-	int node, cpu = event->cpu;
+	int node;
 	struct cs_buffers *buf;
 
-	node = (cpu == -1) ? NUMA_NO_NODE : cpu_to_node(cpu);
+	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;
@@ -412,7 +434,7 @@
 	const u32 *barrier;
 	u32 read_ptr, write_ptr, capacity;
 	u32 status, read_data;
-	unsigned long offset, to_read, flags;
+	unsigned long offset, to_read = 0, flags;
 	struct cs_buffers *buf = sink_config;
 	struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
 
@@ -422,6 +444,11 @@
 	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);
 
@@ -435,7 +462,7 @@
 	 * chance to fix things.
 	 */
 	if (write_ptr % ETB_FRAME_SIZE_WORDS) {
-		dev_err(drvdata->dev,
+		dev_err(&csdev->dev,
 			"write_ptr: %lu not aligned to formatter frame size\n",
 			(unsigned long)write_ptr);
 
@@ -501,7 +528,7 @@
 
 	cur = buf->cur;
 	offset = buf->offset;
-	barrier = barrier_pkt;
+	barrier = coresight_barrier_pkt;
 
 	for (i = 0; i < to_read; i += 4) {
 		buf_ptr = buf->data_pages[cur] + offset;
@@ -529,15 +556,17 @@
 	writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
 
 	/*
-	 * In snapshot mode we have to update the handle->head to point
-	 * to the new location.
+	 * 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 = (cur * PAGE_SIZE) + offset;
-		to_read = buf->nr_pages << PAGE_SHIFT;
-	}
+	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;
@@ -567,7 +596,7 @@
 	}
 	spin_unlock_irqrestore(&drvdata->spinlock, flags);
 
-	dev_dbg(drvdata->dev, "ETB dumped\n");
+	dev_dbg(&drvdata->csdev->dev, "ETB dumped\n");
 }
 
 static int etb_open(struct inode *inode, struct file *file)
@@ -578,7 +607,7 @@
 	if (local_cmpxchg(&drvdata->reading, 0, 1))
 		return -EBUSY;
 
-	dev_dbg(drvdata->dev, "%s: successfully opened\n", __func__);
+	dev_dbg(&drvdata->csdev->dev, "%s: successfully opened\n", __func__);
 	return 0;
 }
 
@@ -588,6 +617,7 @@
 	u32 depth;
 	struct etb_drvdata *drvdata = container_of(file->private_data,
 						   struct etb_drvdata, miscdev);
+	struct device *dev = &drvdata->csdev->dev;
 
 	etb_dump(drvdata);
 
@@ -596,13 +626,14 @@
 		len = depth * 4 - *ppos;
 
 	if (copy_to_user(data, drvdata->buf + *ppos, len)) {
-		dev_dbg(drvdata->dev, "%s: copy_to_user failed\n", __func__);
+		dev_dbg(dev,
+			"%s: copy_to_user failed\n", __func__);
 		return -EFAULT;
 	}
 
 	*ppos += len;
 
-	dev_dbg(drvdata->dev, "%s: %zu bytes copied, %d bytes left\n",
+	dev_dbg(dev, "%s: %zu bytes copied, %d bytes left\n",
 		__func__, len, (int)(depth * 4 - *ppos));
 	return len;
 }
@@ -613,7 +644,7 @@
 						   struct etb_drvdata, miscdev);
 	local_set(&drvdata->reading, 0);
 
-	dev_dbg(drvdata->dev, "%s: released\n", __func__);
+	dev_dbg(&drvdata->csdev->dev, "%s: released\n", __func__);
 	return 0;
 }
 
@@ -689,7 +720,7 @@
 	.name = "mgmt",
 };
 
-const struct attribute_group *coresight_etb_groups[] = {
+static const struct attribute_group *coresight_etb_groups[] = {
 	&coresight_etb_group,
 	&coresight_etb_mgmt_group,
 	NULL,
@@ -704,20 +735,15 @@
 	struct etb_drvdata *drvdata;
 	struct resource *res = &adev->res;
 	struct coresight_desc desc = { 0 };
-	struct device_node *np = adev->dev.of_node;
 
-	if (np) {
-		pdata = of_get_coresight_platform_data(dev, np);
-		if (IS_ERR(pdata))
-			return PTR_ERR(pdata);
-		adev->dev.platform_data = pdata;
-	}
+	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->dev = &adev->dev;
 	drvdata->atclk = devm_clk_get(&adev->dev, "atclk"); /* optional */
 	if (!IS_ERR(drvdata->atclk)) {
 		ret = clk_prepare_enable(drvdata->atclk);
@@ -732,11 +758,11 @@
 		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);
-	pm_runtime_put(&adev->dev);
 
 	if (drvdata->buffer_depth & 0x80000000)
 		return -EINVAL;
@@ -745,6 +771,14 @@
 				    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;
@@ -756,18 +790,32 @@
 	if (IS_ERR(drvdata->csdev))
 		return PTR_ERR(drvdata->csdev);
 
-	drvdata->miscdev.name = pdata->name;
+	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 void 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);
 }
 
 #ifdef CONFIG_PM
@@ -804,6 +852,8 @@
 	{ 0, 0},
 };
 
+MODULE_DEVICE_TABLE(amba, etb_ids);
+
 static struct amba_driver etb_driver = {
 	.drv = {
 		.name	= "coresight-etb10",
@@ -813,6 +863,13 @@
 
 	},
 	.probe		= etb_probe,
+	.remove		= etb_remove,
 	.id_table	= etb_ids,
 };
-builtin_amba_driver(etb_driver);
+
+module_amba_driver(etb_driver);
+
+MODULE_AUTHOR("Pratik Patel <pratikp@codeaurora.org>");
+MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");
+MODULE_DESCRIPTION("Arm CoreSight Embedded Trace Buffer driver");
+MODULE_LICENSE("GPL v2");

--
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