1 files changed, 323 insertions, 4 deletions
diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c
index e9876252a789..a7814e8e657b 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-core.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-core.c
@@ -23,6 +23,7 @@
 #include <linux/spinlock.h>
 #include <linux/pm_runtime.h>
 #include <linux/of.h>
+#include <linux/of_address.h>
 #include <linux/coresight.h>
 #include <linux/amba/bus.h>
 #include <linux/platform_device.h>
@@ -104,6 +105,128 @@ u32 tmc_get_memwidth_mask(struct tmc_drvdata *drvdata)
 	return mask;
 }
 
+static bool is_tmc_crashdata_valid(struct tmc_drvdata *drvdata)
+{
+	struct tmc_crash_metadata *mdata;
+
+	if (!tmc_has_reserved_buffer(drvdata) ||
+	    !tmc_has_crash_mdata_buffer(drvdata))
+		return false;
+
+	mdata = drvdata->crash_mdata.vaddr;
+
+	/* Check version match */
+	if (mdata->version != CS_CRASHDATA_VERSION)
+		return false;
+
+	/* Check for valid metadata */
+	if (!mdata->valid) {
+		dev_dbg(&drvdata->csdev->dev,
+			"Data invalid in tmc crash metadata\n");
+		return false;
+	}
+
+	/*
+	 * Buffer address given by metadata for retrieval of trace data
+	 * from previous boot is expected to be same as the reserved
+	 * trace buffer memory region provided through DTS
+	 */
+	if (drvdata->resrv_buf.paddr != mdata->trace_paddr) {
+		dev_dbg(&drvdata->csdev->dev,
+			"Trace buffer address of previous boot invalid\n");
+		return false;
+	}
+
+	/* Check data integrity of metadata */
+	if (mdata->crc32_mdata != find_crash_metadata_crc(mdata)) {
+		dev_err(&drvdata->csdev->dev,
+			"CRC mismatch in tmc crash metadata\n");
+		return false;
+	}
+	/* Check data integrity of tracedata */
+	if (mdata->crc32_tdata != find_crash_tracedata_crc(drvdata, mdata)) {
+		dev_err(&drvdata->csdev->dev,
+			"CRC mismatch in tmc crash tracedata\n");
+		return false;
+	}
+
+	return true;
+}
+
+static inline ssize_t tmc_get_resvbuf_trace(struct tmc_drvdata *drvdata,
+					  loff_t pos, size_t len, char **bufpp)
+{
+	s64 offset;
+	ssize_t actual = len;
+	struct tmc_resrv_buf *rbuf = &drvdata->resrv_buf;
+
+	if (pos + actual > rbuf->len)
+		actual = rbuf->len - pos;
+	if (actual <= 0)
+		return 0;
+
+	/* Compute the offset from which we read the data */
+	offset = rbuf->offset + pos;
+	if (offset >= rbuf->size)
+		offset -= rbuf->size;
+
+	/* Adjust the length to limit this transaction to end of buffer */
+	actual = (actual < (rbuf->size - offset)) ?
+		actual : rbuf->size - offset;
+
+	*bufpp = (char *)rbuf->vaddr + offset;
+
+	return actual;
+}
+
+static int tmc_prepare_crashdata(struct tmc_drvdata *drvdata)
+{
+	char *bufp;
+	ssize_t len;
+	u32 status, size;
+	u64 rrp, rwp, dba;
+	struct tmc_resrv_buf *rbuf;
+	struct tmc_crash_metadata *mdata;
+
+	mdata = drvdata->crash_mdata.vaddr;
+	rbuf = &drvdata->resrv_buf;
+
+	rrp = mdata->tmc_rrp;
+	rwp = mdata->tmc_rwp;
+	dba = mdata->tmc_dba;
+	status = mdata->tmc_sts;
+	size = mdata->tmc_ram_size << 2;
+
+	/* Sync the buffer pointers */
+	rbuf->offset = rrp - dba;
+	if (status & TMC_STS_FULL)
+		rbuf->len = size;
+	else
+		rbuf->len = rwp - rrp;
+
+	/* Additional sanity checks for validating metadata */
+	if ((rbuf->offset > size) ||
+	    (rbuf->len > size)) {
+		dev_dbg(&drvdata->csdev->dev,
+			"Offset and length invalid in tmc crash metadata\n");
+		return -EINVAL;
+	}
+
+	if (status & TMC_STS_FULL) {
+		len = tmc_get_resvbuf_trace(drvdata, 0x0,
+					    CORESIGHT_BARRIER_PKT_SIZE, &bufp);
+		if (len >= CORESIGHT_BARRIER_PKT_SIZE) {
+			coresight_insert_barrier_packet(bufp);
+			/* Recalculate crc */
+			mdata->crc32_tdata = find_crash_tracedata_crc(drvdata,
+								      mdata);
+			mdata->crc32_mdata = find_crash_metadata_crc(mdata);
+		}
+	}
+
+	return 0;
+}
+
 static int tmc_read_prepare(struct tmc_drvdata *drvdata)
 {
 	int ret = 0;
@@ -222,6 +345,84 @@ static const struct file_operations tmc_fops = {
 	.release	= tmc_release,
 };
 
+static int tmc_crashdata_open(struct inode *inode, struct file *file)
+{
+	int err = 0;
+	unsigned long flags;
+	struct tmc_resrv_buf *rbuf;
+	struct tmc_crash_metadata *mdata;
+	struct tmc_drvdata *drvdata = container_of(file->private_data,
+						   struct tmc_drvdata,
+						   crashdev);
+
+	mdata = drvdata->crash_mdata.vaddr;
+	rbuf = &drvdata->resrv_buf;
+
+	raw_spin_lock_irqsave(&drvdata->spinlock, flags);
+	if (mdata->valid)
+		rbuf->reading = true;
+	else
+		err = -ENOENT;
+	raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);
+	if (err)
+		goto exit;
+
+	nonseekable_open(inode, file);
+	dev_dbg(&drvdata->csdev->dev, "%s: successfully opened\n", __func__);
+exit:
+	return err;
+}
+
+static ssize_t tmc_crashdata_read(struct file *file, char __user *data,
+				  size_t len, loff_t *ppos)
+{
+	char *bufp;
+	ssize_t actual;
+	struct tmc_drvdata *drvdata = container_of(file->private_data,
+						   struct tmc_drvdata,
+						   crashdev);
+
+	actual = tmc_get_resvbuf_trace(drvdata, *ppos, len, &bufp);
+	if (actual <= 0)
+		return 0;
+
+	if (copy_to_user(data, bufp, actual)) {
+		dev_dbg(&drvdata->csdev->dev,
+			"%s: copy_to_user failed\n", __func__);
+		return -EFAULT;
+	}
+
+	*ppos += actual;
+	dev_dbg(&drvdata->csdev->dev, "%zu bytes copied\n", actual);
+
+	return actual;
+}
+
+static int tmc_crashdata_release(struct inode *inode, struct file *file)
+{
+	int ret = 0;
+	unsigned long flags;
+	struct tmc_resrv_buf *rbuf;
+	struct tmc_drvdata *drvdata = container_of(file->private_data,
+						   struct tmc_drvdata,
+						   crashdev);
+
+	rbuf = &drvdata->resrv_buf;
+	raw_spin_lock_irqsave(&drvdata->spinlock, flags);
+	rbuf->reading = false;
+	raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);
+
+	dev_dbg(&drvdata->csdev->dev, "%s: released\n", __func__);
+	return ret;
+}
+
+static const struct file_operations tmc_crashdata_fops = {
+	.owner		= THIS_MODULE,
+	.open		= tmc_crashdata_open,
+	.read		= tmc_crashdata_read,
+	.release	= tmc_crashdata_release,
+};
+
 static enum tmc_mem_intf_width tmc_get_memwidth(u32 devid)
 {
 	enum tmc_mem_intf_width memwidth;
@@ -331,9 +532,40 @@ static ssize_t buffer_size_store(struct device *dev,
 
 static DEVICE_ATTR_RW(buffer_size);
 
+static ssize_t stop_on_flush_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct tmc_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+	return sprintf(buf, "%#x\n", drvdata->stop_on_flush);
+}
+
+static ssize_t stop_on_flush_store(struct device *dev,
+				 struct device_attribute *attr,
+				 const char *buf, size_t size)
+{
+	int ret;
+	u8 val;
+	struct tmc_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+	ret = kstrtou8(buf, 0, &val);
+	if (ret)
+		return ret;
+	if (val)
+		drvdata->stop_on_flush = true;
+	else
+		drvdata->stop_on_flush = false;
+
+	return size;
+}
+
+static DEVICE_ATTR_RW(stop_on_flush);
+
+
 static struct attribute *coresight_tmc_attrs[] = {
 	&dev_attr_trigger_cntr.attr,
 	&dev_attr_buffer_size.attr,
+	&dev_attr_stop_on_flush.attr,
 	NULL,
 };
 
@@ -398,6 +630,67 @@ static inline bool tmc_etr_has_non_secure_access(struct tmc_drvdata *drvdata)
 
 static const struct amba_id tmc_ids[];
 
+static int of_tmc_get_reserved_resource_by_name(struct device *dev,
+						const char *name,
+						struct resource *res)
+{
+	int index, rc = -ENODEV;
+	struct device_node *node;
+
+	if (!is_of_node(dev->fwnode))
+		return -ENODEV;
+
+	index = of_property_match_string(dev->of_node, "memory-region-names",
+					 name);
+	if (index < 0)
+		return rc;
+
+	node = of_parse_phandle(dev->of_node, "memory-region", index);
+	if (!node)
+		return rc;
+
+	if (!of_address_to_resource(node, 0, res) &&
+	    res->start != 0 && resource_size(res) != 0)
+		rc = 0;
+	of_node_put(node);
+
+	return rc;
+}
+
+static void tmc_get_reserved_region(struct device *parent)
+{
+	struct tmc_drvdata *drvdata = dev_get_drvdata(parent);
+	struct resource res;
+
+	if (of_tmc_get_reserved_resource_by_name(parent, "tracedata", &res))
+		return;
+
+	drvdata->resrv_buf.vaddr = memremap(res.start,
+						resource_size(&res),
+						MEMREMAP_WC);
+	if (IS_ERR_OR_NULL(drvdata->resrv_buf.vaddr)) {
+		dev_err(parent, "Reserved trace buffer mapping failed\n");
+		return;
+	}
+
+	drvdata->resrv_buf.paddr = res.start;
+	drvdata->resrv_buf.size  = resource_size(&res);
+
+	if (of_tmc_get_reserved_resource_by_name(parent, "metadata", &res))
+		return;
+
+	drvdata->crash_mdata.vaddr = memremap(res.start,
+					       resource_size(&res),
+					       MEMREMAP_WC);
+	if (IS_ERR_OR_NULL(drvdata->crash_mdata.vaddr)) {
+		dev_err(parent, "Metadata memory mapping failed\n");
+		return;
+	}
+
+	drvdata->crash_mdata.paddr = res.start;
+	drvdata->crash_mdata.size  = resource_size(&res);
+}
+
 /* Detect and initialise the capabilities of a TMC ETR */
 static int tmc_etr_setup_caps(struct device *parent, u32 devid,
 			      struct csdev_access *access)
@@ -470,6 +763,22 @@ static u32 tmc_etr_get_max_burst_size(struct device *dev)
 	return burst_size;
 }
 
+static void register_crash_dev_interface(struct tmc_drvdata *drvdata,
+					 const char *name)
+{
+	drvdata->crashdev.name =
+		devm_kasprintf(&drvdata->csdev->dev, GFP_KERNEL, "%s_%s", "crash", name);
+	drvdata->crashdev.minor = MISC_DYNAMIC_MINOR;
+	drvdata->crashdev.fops = &tmc_crashdata_fops;
+	if (misc_register(&drvdata->crashdev)) {
+		dev_dbg(&drvdata->csdev->dev,
+			"Failed to setup user interface for crashdata\n");
+		drvdata->crashdev.fops = NULL;
+	} else
+		dev_info(&drvdata->csdev->dev,
+			"Valid crash tracedata found\n");
+}
+
 static int __tmc_probe(struct device *dev, struct resource *res)
 {
 	int ret = 0;
@@ -492,7 +801,7 @@ static int __tmc_probe(struct device *dev, struct resource *res)
 	drvdata->base = base;
 	desc.access = CSDEV_ACCESS_IOMEM(base);
 
-	spin_lock_init(&drvdata->spinlock);
+	raw_spin_lock_init(&drvdata->spinlock);
 
 	devid = readl_relaxed(drvdata->base + CORESIGHT_DEVID);
 	drvdata->config_type = BMVAL(devid, 6, 7);
@@ -508,6 +817,8 @@ static int __tmc_probe(struct device *dev, struct resource *res)
 		drvdata->size = readl_relaxed(drvdata->base + TMC_RSZ) * 4;
 	}
 
+	tmc_get_reserved_region(dev);
+
 	desc.dev = dev;
 
 	switch (drvdata->config_type) {
@@ -568,9 +879,15 @@ static int __tmc_probe(struct device *dev, struct resource *res)
 	drvdata->miscdev.minor = MISC_DYNAMIC_MINOR;
 	drvdata->miscdev.fops = &tmc_fops;
 	ret = misc_register(&drvdata->miscdev);
-	if (ret)
+	if (ret) {
 		coresight_unregister(drvdata->csdev);
+		goto out;
+	}
+
 out:
+	if (is_tmc_crashdata_valid(drvdata) &&
+	    !tmc_prepare_crashdata(drvdata))
+		register_crash_dev_interface(drvdata, desc.name);
 	return ret;
 }
 
@@ -596,7 +913,7 @@ static void tmc_shutdown(struct amba_device *adev)
 	unsigned long flags;
 	struct tmc_drvdata *drvdata = amba_get_drvdata(adev);
 
-	spin_lock_irqsave(&drvdata->spinlock, flags);
+	raw_spin_lock_irqsave(&drvdata->spinlock, flags);
 
 	if (coresight_get_mode(drvdata->csdev) == CS_MODE_DISABLED)
 		goto out;
@@ -610,7 +927,7 @@ static void tmc_shutdown(struct amba_device *adev)
 	 * the system is going down after this.
 	 */
 out:
-	spin_unlock_irqrestore(&drvdata->spinlock, flags);
+	raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);
 }
 
 static void __tmc_remove(struct device *dev)
@@ -623,6 +940,8 @@ static void __tmc_remove(struct device *dev)
 	 * handler to this device is closed.
 	 */
 	misc_deregister(&drvdata->miscdev);
+	if (drvdata->crashdev.fops)
+		misc_deregister(&drvdata->crashdev);
 	coresight_unregister(drvdata->csdev);
 }