[PATCH RESEND 1/4] hwtracing: Add trace function support for HiSilicon PCIe Tune and Trace device

[Yicong Yang]

HiSilicon PCIe tune and trace device(PTT) is a PCIe Root Complex
integrated Endpoint(RCiEP) device, providing the capability
to dynamically monitor and tune the PCIe traffic(tune),
and trace the TLP headers(trace).

Add the driver for the device to enable the trace function. The driver
will create debugfs directory for each PTT device, and users can
operate the device through the files under its directory.

Signed-off-by: Yicong Yang <yangyicong@xxxxxxxxxxxxx>
---
 drivers/Makefile                       |    1 +
 drivers/hwtracing/Kconfig              |    2 +
 drivers/hwtracing/hisilicon/Kconfig    |   11 +
 drivers/hwtracing/hisilicon/Makefile   |    2 +
 drivers/hwtracing/hisilicon/hisi_ptt.c | 1449 ++++++++++++++++++++++++++++++++
 5 files changed, 1465 insertions(+)
 create mode 100644 drivers/hwtracing/hisilicon/Kconfig
 create mode 100644 drivers/hwtracing/hisilicon/Makefile
 create mode 100644 drivers/hwtracing/hisilicon/hisi_ptt.c

diff --git a/drivers/Makefile b/drivers/Makefile
index 6fba7da..9a0f76d 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -174,6 +174,7 @@ obj-$(CONFIG_PERF_EVENTS)	+= perf/
 obj-$(CONFIG_RAS)		+= ras/
 obj-$(CONFIG_USB4)		+= thunderbolt/
 obj-$(CONFIG_CORESIGHT)		+= hwtracing/coresight/
+obj-$(CONFIG_HISI_PTT)		+= hwtracing/hisilicon/
 obj-y				+= hwtracing/intel_th/
 obj-$(CONFIG_STM)		+= hwtracing/stm/
 obj-$(CONFIG_ANDROID)		+= android/
diff --git a/drivers/hwtracing/Kconfig b/drivers/hwtracing/Kconfig
index 1308583..e3796b1 100644
--- a/drivers/hwtracing/Kconfig
+++ b/drivers/hwtracing/Kconfig
@@ -5,4 +5,6 @@ source "drivers/hwtracing/stm/Kconfig"
 
 source "drivers/hwtracing/intel_th/Kconfig"
 
+source "drivers/hwtracing/hisilicon/Kconfig"
+
 endmenu
diff --git a/drivers/hwtracing/hisilicon/Kconfig b/drivers/hwtracing/hisilicon/Kconfig
new file mode 100644
index 0000000..e169771
--- /dev/null
+++ b/drivers/hwtracing/hisilicon/Kconfig
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config HISI_PTT
+	tristate "HiSilicon PCIe Tune and Trace Device"
+	depends on ARM64
+	depends on PCI && PCI_MSI
+	depends on HAS_DMA && HAS_IOMEM
+	depends on DEBUG_FS
+	help
+	  HiSilicon PCIe Tune and Trace Device exist as a PCIe iEP
+	  device, provides support for PCIe traffic tuning and
+	  tracing TLP headers to the memory.
diff --git a/drivers/hwtracing/hisilicon/Makefile b/drivers/hwtracing/hisilicon/Makefile
new file mode 100644
index 0000000..908c09a
--- /dev/null
+++ b/drivers/hwtracing/hisilicon/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_HISI_PTT) += hisi_ptt.o
diff --git a/drivers/hwtracing/hisilicon/hisi_ptt.c b/drivers/hwtracing/hisilicon/hisi_ptt.c
new file mode 100644
index 0000000..a1feece
--- /dev/null
+++ b/drivers/hwtracing/hisilicon/hisi_ptt.c
@@ -0,0 +1,1449 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for HiSilicon PCIe tune and trace device
+ *
+ * Copyright (c) 2021 HiSilicon Limited.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/kfifo.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/seq_file.h>
+#include <linux/pci.h>
+#include <linux/workqueue.h>
+
+#define HISI_PTT_CTRL_STR_LEN			40
+#define HISI_PTT_DEFAULT_TRACE_BUF_CNT		64
+#define HISI_PTT_FILTER_UPDATE_FIFO_SIZE	16
+
+#define HISI_PTT_RESET_WAIT_MS		1000UL
+#define HISI_PTT_WORK_DELAY_MS		100UL
+#define HISI_PTT_WAIT_TIMEOUT_US	1000000UL
+#define HISI_PTT_WAIT_POLL_INTERVAL_US	100UL
+
+#define HISI_PTT_IRQ_NUMS	1
+#define HISI_PTT_DMA_IRQ	0
+#define HISI_PTT_DMA_NUMS	4
+
+#define HISI_PTT_TUNING_CTRL		0x0000
+#define   HISI_PTT_TUNING_CTRL_CODE	GENMASK(15, 0)
+#define   HISI_PTT_TUNING_CTRL_SUB	GENMASK(23, 16)
+#define   HISI_PTT_TUNING_CTRL_CHN	GENMASK(31, 24)
+#define HISI_PTT_TUNING_DATA		0x0004
+#define   HISI_PTT_TUNING_DATA_VAL_MASK	GENMASK(15, 0)
+#define HISI_PTT_TRACE_ADDR_SIZE	0x0800
+#define HISI_PTT_TRACE_ADDR_BASE_LO_0	0x0810
+#define HISI_PTT_TRACE_ADDR_BASE_HI_0	0x0814
+#define HISI_PTT_TRACE_ADDR_STRIDE	0x8
+#define HISI_PTT_TRACE_CTRL		0x0850
+#define   HISI_PTT_TRACE_CTRL_EN	BIT(0)
+#define   HISI_PTT_TRACE_CTRL_RST	BIT(1)
+#define   HISI_PTT_TRACE_CTRL_RXTX_SEL	GENMASK(3, 2)
+#define   HISI_PTT_TRACE_CTRL_TYPE_SEL	GENMASK(7, 4)
+#define   HISI_PTT_TRACE_CTRL_DATA_FORMAT	BIT(14)
+#define   HISI_PTT_TRACE_CTRL_FILTER_MODE	BIT(15)
+#define   HISI_PTT_TRACE_CTRL_TARGET_SEL	GENMASK(31, 16)
+#define HISI_PTT_TRACE_INT_STAT		0x0890
+#define   HISI_PTT_TRACE_INT_STAT_MASK	GENMASK(3, 0)
+#define HISI_PTT_TRACE_INT_MASK_REG	0x0894
+#define HISI_PTT_TUNING_INT_STAT	0x0898
+#define   HISI_PTT_TUNING_INT_STAT_MASK	BIT(0)
+#define HISI_PTT_TUNING_INT_MASK	0x089c
+#define HISI_PTT_TRACE_WR_STS		0x08a0
+#define   HISI_PTT_TRACE_WR_STS_WRITE	GENMASK(27, 0)
+#define   HISI_PTT_TRACE_WR_STS_BUFFER	GENMASK(29, 28)
+#define HISI_PTT_TRACE_STS		0x08b0
+#define   HISI_PTT_TRACE_IDLE		BIT(0)
+#define HISI_PTT_DEVICE_RANGE		0x0fe0
+
+#define HISI_PCIE_CORE_PORT_ID(v)	(((v) & 7) << 1)
+
+static struct dentry *hisi_ptt_debugfs_root;
+
+struct hisi_ptt_debugfs_file_desc {
+	struct hisi_ptt *hisi_ptt;
+	const char *name;
+	const struct file_operations *fops;
+};
+
+#define PTT_FILE_INIT(__name, __fops)	\
+	{ .name = __name, .fops = __fops }
+
+struct hisi_ptt_trace_event_desc {
+	const char *name;
+	u32 event_code;
+};
+
+#define PTT_TRACE_EVENT_INIT(__name, __event_code) \
+	{ .name = __name, .event_code = __event_code }
+
+enum hisi_ptt_trace_rxtx {
+	HISI_PTT_TRACE_RX = 0,
+	HISI_PTT_TRACE_TX,
+	HISI_PTT_TRACE_RXTX,
+	HISI_PTT_TRACE_RXTX_NO_DMA_P2P,
+};
+
+static const struct hisi_ptt_trace_event_desc trace_rxtx[] = {
+	PTT_TRACE_EVENT_INIT("rx",
+			      HISI_PTT_TRACE_RX),
+	PTT_TRACE_EVENT_INIT("tx",
+			      HISI_PTT_TRACE_TX),
+	PTT_TRACE_EVENT_INIT("rxtx",
+			      HISI_PTT_TRACE_RXTX),
+	PTT_TRACE_EVENT_INIT("rxtx_no_dma_p2p",
+			      HISI_PTT_TRACE_RXTX_NO_DMA_P2P),
+};
+#define HISI_PTT_TRACE_DEFAULT_RXTX	trace_rxtx[2]
+
+
+enum hisi_ptt_trace_event {
+	HISI_PTT_TRACE_POSTED_REQUEST		= 1,
+	HISI_PTT_TRACE_NON_POSTED_REQUEST	= 2,
+	HISI_PTT_TRACE_COMPLETION		= 4,
+	HISI_PTT_TRACE_ALL			= 7,
+};
+
+static const struct hisi_ptt_trace_event_desc trace_events[] = {
+	PTT_TRACE_EVENT_INIT("all",
+			      HISI_PTT_TRACE_POSTED_REQUEST),
+	PTT_TRACE_EVENT_INIT("posted_request",
+			      HISI_PTT_TRACE_NON_POSTED_REQUEST),
+	PTT_TRACE_EVENT_INIT("non-posted_request",
+			      HISI_PTT_TRACE_COMPLETION),
+	PTT_TRACE_EVENT_INIT("completion",
+			      HISI_PTT_TRACE_ALL),
+};
+#define HISI_PTT_TRACE_DEFAULT_EVENT	trace_events[0]
+
+static const unsigned int available_buflet_size[] = {
+	0x00200000,	/* 2  MiB */
+	0x00400000,	/* 4  MiB */
+};
+#define HISI_PTT_TRACE_DEFAULT_BUFLET_SIZE	available_buflet_size[0]
+
+struct hisi_ptt_dma_buflet {
+	struct list_head list;
+	unsigned int size;
+	dma_addr_t dma;
+
+	/*
+	 * The address of the buflet holding the trace data.
+	 * See Documentation/trace/hisi-ptt.rst for the details
+	 * of the data format.
+	 */
+	u32 *addr;
+	int index;
+};
+
+enum hisi_ptt_trace_data_format {
+	HISI_PTT_TRACE_DATA_4DW = 0,
+	HISI_PTT_TRACE_DATA_8DW,
+};
+
+struct hisi_ptt_trace_ctrl {
+	struct list_head trace_buf;
+	struct hisi_ptt_dma_buflet *cur;
+	u64 buflet_nums;
+	u32 buflet_size;
+	unsigned int status; /* 0:idle, 1:tracing */
+#define	HISI_PTT_TRACE_STATUS_OFF	0
+#define	HISI_PTT_TRACE_STATUS_ON	1
+
+	enum hisi_ptt_trace_data_format tr_format;
+	enum hisi_ptt_trace_event tr_event;
+	enum hisi_ptt_trace_rxtx rxtx;
+};
+
+struct hisi_ptt_filter_desc {
+	struct list_head list;
+	struct pci_dev *pdev;
+	u16 val;
+};
+
+/* Structure containing the information for filter updating */
+struct hisi_ptt_filter_update_info {
+	struct pci_dev *pdev;
+	bool is_port;
+	bool is_add;
+	u32 port_devid;
+	u16 val;
+};
+
+struct hisi_ptt {
+	struct notifier_block hisi_ptt_nb;
+	struct dentry *debugfs_dir;
+	struct pci_dev *pdev;
+	void __iomem *iobase;
+	/* protects the hisi_ptt structure */
+	struct mutex mutex;
+	const char *name;
+
+	/*
+	 * We use a delayed work here to avoid indefinitely waiting for
+	 * the hisi_ptt->mutex which protecting the filter list. The
+	 * work will be delayed only if the mutex can not be held,
+	 * otherwise no delay will be applied.
+	 */
+	struct delayed_work work;
+	spinlock_t filter_update_lock;
+	DECLARE_KFIFO(filter_update_kfifo, struct hisi_ptt_filter_update_info,
+		      HISI_PTT_FILTER_UPDATE_FIFO_SIZE);
+
+	/*
+	 * The upper and lower BDF numbers of the root port,
+	 * which PTT device can control and trace.
+	 */
+	u16 upper;
+	u16 lower;
+
+	/*
+	 * The trace TLP headers can either be filtered by certain
+	 * root port, or by the requester ID. Organize the filters
+	 * by @port_filters and @req_filters here.
+	 */
+	struct list_head port_filters;
+	struct list_head req_filters;
+	struct hisi_ptt_trace_ctrl trace_ctrl;
+	struct {
+		bool is_port;
+		u16 val;
+	} cur_filter;
+};
+
+static int hisi_ptt_write_to_buffer(void *buf, size_t len, loff_t *pos,
+				    const void __user *ubuf, size_t count)
+{
+	char *cp;
+
+	if (simple_write_to_buffer(buf, len, pos, ubuf, count) < 0)
+		return -EINVAL;
+
+	cp = strchr(buf, '\n');
+	if (cp)
+		*cp = '\0';
+
+	return 0;
+}
+
+static u16 hisi_ptt_get_filter_val(struct pci_dev *pdev)
+{
+	if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT)
+		return BIT(HISI_PCIE_CORE_PORT_ID(PCI_SLOT(pdev->devfn)));
+	else
+		return PCI_DEVID(pdev->bus->number, pdev->devfn);
+}
+
+static int hisi_ptt_wait_trace_hw_idle(struct hisi_ptt *hisi_ptt)
+{
+	u32 val;
+
+	return readl_poll_timeout(hisi_ptt->iobase + HISI_PTT_TRACE_STS, val,
+				  val & HISI_PTT_TRACE_IDLE,
+				  HISI_PTT_WAIT_POLL_INTERVAL_US,
+				  HISI_PTT_WAIT_TIMEOUT_US);
+}
+
+static void hisi_ptt_free_trace_buf(struct hisi_ptt *hisi_ptt)
+{
+	struct hisi_ptt_trace_ctrl *ctrl = &hisi_ptt->trace_ctrl;
+	struct device *dev = &hisi_ptt->pdev->dev;
+	struct hisi_ptt_dma_buflet *buflet, *tbuflet;
+
+	if (list_empty(&ctrl->trace_buf))
+		return;
+
+	list_for_each_entry_safe(buflet, tbuflet, &ctrl->trace_buf, list) {
+		dma_free_coherent(dev, buflet->size, buflet->addr, buflet->dma);
+		list_del(&buflet->list);
+		kfree(buflet);
+	}
+}
+
+static int hisi_ptt_alloc_trace_buf(struct hisi_ptt *hisi_ptt)
+{
+	struct hisi_ptt_trace_ctrl *ctrl = &hisi_ptt->trace_ctrl;
+	struct device *dev = &hisi_ptt->pdev->dev;
+	struct hisi_ptt_dma_buflet *buflet;
+	int i, ret;
+
+	/* Make sure the trace buffer is empty before allocating */
+	if (!list_empty(&ctrl->trace_buf))
+		hisi_ptt_free_trace_buf(hisi_ptt);
+
+	for (i = 0; i < ctrl->buflet_nums; ++i) {
+		buflet = kzalloc(sizeof(*buflet), GFP_KERNEL);
+		if (!buflet) {
+			ret = -ENOMEM;
+			goto err;
+		}
+		buflet->addr = dma_alloc_coherent(dev, ctrl->buflet_size,
+						  &buflet->dma, GFP_KERNEL);
+		if (!buflet->addr) {
+			kfree(buflet);
+			ret = -ENOMEM;
+			goto err;
+		}
+
+		buflet->index = i;
+		buflet->size = ctrl->buflet_size;
+		list_add_tail(&buflet->list, &ctrl->trace_buf);
+	}
+
+	return 0;
+
+err:
+	hisi_ptt_free_trace_buf(hisi_ptt);
+	return ret;
+}
+
+static void hisi_ptt_trace_end(struct hisi_ptt *hisi_ptt)
+{
+	writel(0, hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
+	hisi_ptt->trace_ctrl.status = HISI_PTT_TRACE_STATUS_OFF;
+	hisi_ptt->trace_ctrl.cur = NULL;
+}
+
+static int hisi_ptt_trace_start(struct hisi_ptt *hisi_ptt)
+{
+	struct hisi_ptt_trace_ctrl *ctrl = &hisi_ptt->trace_ctrl;
+	u32 val;
+	int i;
+
+	if (!hisi_ptt->cur_filter.val) {
+		pci_err(hisi_ptt->pdev, "no filter specified\n");
+		return -ENODEV;
+	}
+
+	if (!ctrl->tr_event) {
+		pci_err(hisi_ptt->pdev, "no trace type specified\n");
+		return -EINVAL;
+	}
+
+	/* Check device idle before start trace */
+	if (hisi_ptt_wait_trace_hw_idle(hisi_ptt)) {
+		pci_err(hisi_ptt->pdev, "the device is still busy\n");
+		return -EBUSY;
+	}
+
+	/* Reset the DMA before start tracing */
+	val = readl(hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
+	val |= HISI_PTT_TRACE_CTRL_RST;
+	writel(val, hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
+
+	/* Wait for the reset finished */
+	msleep(HISI_PTT_RESET_WAIT_MS);
+
+	val = readl(hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
+	val &= ~HISI_PTT_TRACE_CTRL_RST;
+	writel(val, hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
+
+	/* clear the interrupt status */
+	writel(HISI_PTT_TRACE_INT_STAT_MASK,
+	       hisi_ptt->iobase + HISI_PTT_TRACE_INT_STAT);
+	writel(0, hisi_ptt->iobase + HISI_PTT_TRACE_INT_MASK_REG);
+
+	for (i = 0; i < HISI_PTT_DMA_NUMS; ++i) {
+		if (!ctrl->cur)
+			ctrl->cur = list_first_entry(&ctrl->trace_buf,
+						     struct hisi_ptt_dma_buflet,
+						     list);
+		else
+			ctrl->cur = list_next_entry(ctrl->cur, list);
+
+		writel(lower_32_bits(ctrl->cur->dma),
+		       hisi_ptt->iobase + HISI_PTT_TRACE_ADDR_BASE_LO_0 +
+		       i * HISI_PTT_TRACE_ADDR_STRIDE);
+		writel(upper_32_bits(ctrl->cur->dma),
+		       hisi_ptt->iobase + HISI_PTT_TRACE_ADDR_BASE_HI_0 +
+		       i * HISI_PTT_TRACE_ADDR_STRIDE);
+	}
+	writel(ctrl->buflet_size, hisi_ptt->iobase + HISI_PTT_TRACE_ADDR_SIZE);
+
+	/* set the trace control register */
+	val = 0;
+	val |= FIELD_PREP(HISI_PTT_TRACE_CTRL_TYPE_SEL, ctrl->tr_event);
+	val |= FIELD_PREP(HISI_PTT_TRACE_CTRL_RXTX_SEL, ctrl->rxtx);
+	val |= FIELD_PREP(HISI_PTT_TRACE_CTRL_DATA_FORMAT, ctrl->tr_format);
+	val |= FIELD_PREP(HISI_PTT_TRACE_CTRL_FILTER_MODE,
+			  hisi_ptt->cur_filter.is_port ? 0 : 1);
+	val |= FIELD_PREP(HISI_PTT_TRACE_CTRL_TARGET_SEL,
+			  hisi_ptt->cur_filter.val);
+
+	val |= HISI_PTT_TRACE_CTRL_EN;
+	writel(val, hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
+
+	ctrl->status = HISI_PTT_TRACE_STATUS_ON;
+
+	return 0;
+}
+
+#define HISI_PTT_TRACE_ATTR(__name)					\
+static int __name ## _open(struct inode *inode, struct file *filp)	\
+{									\
+	struct hisi_ptt_debugfs_file_desc *desc = inode->i_private;	\
+	struct hisi_ptt *hisi_ptt = desc->hisi_ptt;			\
+	if (!mutex_trylock(&hisi_ptt->mutex))				\
+		return -EBUSY;						\
+	return single_open(filp, __name ## _show, hisi_ptt);		\
+}									\
+static int __name ## _release(struct inode *inode, struct file *filp)	\
+{									\
+	struct hisi_ptt_debugfs_file_desc *desc = inode->i_private;	\
+	struct hisi_ptt *hisi_ptt = desc->hisi_ptt;			\
+	mutex_unlock(&hisi_ptt->mutex);					\
+	return seq_release(inode, filp);				\
+}									\
+static const struct file_operations __name ## _fops = {			\
+	.owner		= THIS_MODULE,					\
+	.open		= __name ## _open,				\
+	.read		= seq_read,					\
+	.write		= __name ## _write,				\
+	.llseek		= seq_lseek,					\
+	.release	= __name ## _release,				\
+}
+
+static void hisi_ptt_print_filter_list(struct seq_file *m,
+				       struct hisi_ptt *hisi_ptt,
+				       struct list_head *filter_list,
+				       bool port_filter)
+{
+	struct hisi_ptt_filter_desc *filter;
+
+	list_for_each_entry(filter, filter_list, list) {
+		struct pci_dev *pdev = filter->pdev;
+		bool selected = false;
+
+		if (port_filter && hisi_ptt->cur_filter.is_port)
+			selected = filter->val & hisi_ptt->cur_filter.val;
+		else
+			selected = filter->val == hisi_ptt->cur_filter.val;
+
+		seq_printf(m, "%s%04x:%02x:%02x.%u%s\n",
+			   selected ? "[" : "",
+			   pci_domain_nr(pdev->bus),
+			   pdev->bus->number, PCI_SLOT(pdev->devfn),
+			   PCI_FUNC(pdev->devfn),
+			   selected ? "]" : "");
+	}
+}
+
+static int hisi_ptt_set_filter_show(struct seq_file *m, void *v)
+{
+	struct hisi_ptt *hisi_ptt = m->private;
+
+	if (list_empty(&hisi_ptt->port_filters)) {
+		seq_puts(m, "#### No available filter ####\n");
+		return 0;
+	}
+
+	seq_puts(m, "#### Root Ports ####\n");
+	hisi_ptt_print_filter_list(m, hisi_ptt, &hisi_ptt->port_filters, true);
+
+	if (list_empty(&hisi_ptt->req_filters))
+		return 0;
+
+	seq_puts(m, "#### Functions ####\n");
+	hisi_ptt_print_filter_list(m, hisi_ptt, &hisi_ptt->req_filters, false);
+
+	return 0;
+}
+
+static int hisi_ptt_parse_set_filter(struct hisi_ptt *hisi_ptt, const char *buf)
+{
+	struct hisi_ptt_filter_desc *filter;
+	u32 domain, bus, dev, fn, devfn;
+	struct list_head *filter_list;
+	struct pci_dev *pdev;
+	u16 filter_val;
+	int num;
+
+	/*
+	 * the input should be like 0000:80:01.1, etc. Parse it
+	 * and check whether it's in the available func list.
+	 */
+	num = sscanf(buf, "%04x:%02x:%02x.%u", &domain, &bus, &dev, &fn);
+	if (num != 4)
+		return -EINVAL;
+
+	devfn = PCI_DEVFN(dev, fn);
+	pdev = pci_get_domain_bus_and_slot(domain, bus, devfn);
+	if (!pdev)
+		return -EINVAL;
+
+	filter_val = hisi_ptt_get_filter_val(pdev);
+	if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT)
+		filter_list = &hisi_ptt->port_filters;
+	else
+		filter_list = &hisi_ptt->req_filters;
+
+	list_for_each_entry(filter, filter_list, list) {
+		if (filter_val != filter->val)
+			continue;
+
+		if (hisi_ptt->cur_filter.is_port &&
+		    pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT)
+			hisi_ptt->cur_filter.val |= filter_val;
+		else
+			hisi_ptt->cur_filter.val = filter_val;
+
+		hisi_ptt->cur_filter.is_port = pci_pcie_type(pdev) ==
+					       PCI_EXP_TYPE_ROOT_PORT;
+
+		pci_dev_put(pdev);
+		return 0;
+	}
+
+	pci_dev_put(pdev);
+	return -EINVAL;
+}
+
+static ssize_t hisi_ptt_set_filter_write(struct file *filp,
+					 const char __user *buf,
+					 size_t count, loff_t *pos)
+{
+	struct seq_file *m = filp->private_data;
+	struct hisi_ptt *hisi_ptt = m->private;
+	char tbuf[HISI_PTT_CTRL_STR_LEN];
+
+	if (list_empty(&hisi_ptt->port_filters))
+		return -EINVAL;
+
+	if (hisi_ptt_write_to_buffer(tbuf, HISI_PTT_CTRL_STR_LEN - 1,
+				     pos, buf, count))
+		return -EINVAL;
+
+	if (!strlen(tbuf)) {
+		hisi_ptt->cur_filter.val = 0;
+		hisi_ptt->cur_filter.is_port = false;
+		return count;
+	}
+
+	if (hisi_ptt_parse_set_filter(hisi_ptt, tbuf) < 0)
+		return -EINVAL;
+
+	return count;
+}
+HISI_PTT_TRACE_ATTR(hisi_ptt_set_filter);
+
+static int hisi_ptt_set_direction_show(struct seq_file *m, void *v)
+{
+	struct hisi_ptt *hisi_ptt = m->private;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(trace_rxtx); ++i) {
+		bool selected = false;
+
+		if (hisi_ptt->trace_ctrl.rxtx == trace_rxtx[i].event_code)
+			selected = true;
+
+		seq_printf(m, "%s%s%s  ",
+			   selected ? "[" : "", trace_rxtx[i].name,
+			   selected ? "]" : "");
+	}
+	seq_putc(m, '\n');
+
+	return 0;
+}
+
+static ssize_t hisi_ptt_set_direction_write(struct file *filp,
+					    const char __user *buf,
+					    size_t count, loff_t *pos)
+{
+	struct seq_file *m = filp->private_data;
+	struct hisi_ptt *hisi_ptt = m->private;
+	char tbuf[HISI_PTT_CTRL_STR_LEN];
+	int i;
+
+	if (hisi_ptt_write_to_buffer(tbuf, HISI_PTT_CTRL_STR_LEN - 1,
+				     pos, buf, count))
+		return -EINVAL;
+
+	for (i = 0; i < ARRAY_SIZE(trace_rxtx); ++i) {
+		if (!strcmp(tbuf, trace_rxtx[i].name)) {
+			hisi_ptt->trace_ctrl.rxtx = trace_rxtx[i].event_code;
+			return count;
+		}
+	}
+
+	return -EINVAL;
+}
+HISI_PTT_TRACE_ATTR(hisi_ptt_set_direction);
+
+static int hisi_ptt_set_trace_type_show(struct seq_file *m, void *v)
+{
+	struct hisi_ptt *hisi_ptt = m->private;
+	bool select_all = false;
+	int i;
+
+	if (hisi_ptt->trace_ctrl.tr_event == trace_events[0].event_code)
+		select_all = true;
+
+	for (i = 0; i < ARRAY_SIZE(trace_events); ++i) {
+		bool selected = false;
+
+		if (((hisi_ptt->trace_ctrl.tr_event &
+		      trace_events[i].event_code) &&
+		     !select_all && i) || (i == 0 && select_all))
+			selected = true;
+
+		seq_printf(m, "%s%s%s  ",
+			   selected ? "[" : "", trace_events[i].name,
+			   selected ? "]" : "");
+	}
+	seq_putc(m, '\n');
+
+	return 0;
+}
+
+static ssize_t hisi_ptt_set_trace_type_write(struct file *filp,
+					     const char __user *buf,
+					     size_t count, loff_t *pos)
+{
+	struct seq_file *m = filp->private_data;
+	struct hisi_ptt *hisi_ptt = m->private;
+	char tbuf[HISI_PTT_CTRL_STR_LEN];
+	int i;
+
+	if (hisi_ptt_write_to_buffer(tbuf, HISI_PTT_CTRL_STR_LEN - 1,
+				     pos, buf, count))
+		return -EINVAL;
+
+	if (!strlen(tbuf)) {
+		hisi_ptt->trace_ctrl.tr_event = 0;
+		return count;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(trace_events); ++i) {
+		if (!strcmp(tbuf, trace_events[i].name)) {
+			hisi_ptt->trace_ctrl.tr_event |= trace_events[i].event_code;
+			return count;
+		}
+	}
+
+	return -EINVAL;
+}
+HISI_PTT_TRACE_ATTR(hisi_ptt_set_trace_type);
+
+static int hisi_ptt_trace_on_get(void *data, u64 *val)
+{
+	struct hisi_ptt_debugfs_file_desc *desc = data;
+	struct hisi_ptt *hisi_ptt = desc->hisi_ptt;
+
+	if (!mutex_trylock(&hisi_ptt->mutex))
+		return -EBUSY;
+
+	*val = hisi_ptt->trace_ctrl.status;
+
+	mutex_unlock(&hisi_ptt->mutex);
+	return 0;
+}
+
+static int hisi_ptt_trace_on_set(void *data, u64 val)
+{
+	struct hisi_ptt_debugfs_file_desc *desc = data;
+	struct hisi_ptt *hisi_ptt = desc->hisi_ptt;
+	int ret = 0;
+
+	if (!mutex_trylock(&hisi_ptt->mutex))
+		return -EBUSY;
+
+	if (val) {
+		if (hisi_ptt->trace_ctrl.status == HISI_PTT_TRACE_STATUS_ON)
+			goto out;
+
+		ret = hisi_ptt_alloc_trace_buf(hisi_ptt);
+		if (ret)
+			goto out;
+
+		ret = hisi_ptt_trace_start(hisi_ptt);
+		if (ret) {
+			hisi_ptt_free_trace_buf(hisi_ptt);
+			goto out;
+		}
+	} else {
+		if (hisi_ptt->trace_ctrl.status == HISI_PTT_TRACE_STATUS_OFF)
+			goto out;
+
+		hisi_ptt_trace_end(hisi_ptt);
+	}
+
+out:
+	mutex_unlock(&hisi_ptt->mutex);
+	return ret;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(hisi_ptt_trace_on_fops, hisi_ptt_trace_on_get,
+			 hisi_ptt_trace_on_set, "%llu\n");
+
+static int hisi_ptt_set_trace_buf_nums_get(void *data, u64 *val)
+{
+	struct hisi_ptt_debugfs_file_desc *desc = data;
+	struct hisi_ptt *hisi_ptt = desc->hisi_ptt;
+
+	if (!mutex_trylock(&hisi_ptt->mutex))
+		return -EBUSY;
+
+	*val = hisi_ptt->trace_ctrl.buflet_nums;
+
+	mutex_unlock(&hisi_ptt->mutex);
+	return 0;
+}
+
+static int hisi_ptt_set_trace_buf_nums_set(void *data, u64 val)
+{
+	struct hisi_ptt_debugfs_file_desc *desc = data;
+	struct hisi_ptt *hisi_ptt = desc->hisi_ptt;
+
+	if (val < HISI_PTT_DMA_NUMS) {
+		pci_warn(hisi_ptt->pdev, "buflet numbers should be more than %d\n",
+			 HISI_PTT_DMA_NUMS - 1);
+		return -EINVAL;
+	}
+
+	if (!mutex_trylock(&hisi_ptt->mutex))
+		return -EBUSY;
+
+	hisi_ptt->trace_ctrl.buflet_nums = val;
+
+	mutex_unlock(&hisi_ptt->mutex);
+	return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(hisi_ptt_set_trace_buf_nums_fops,
+			 hisi_ptt_set_trace_buf_nums_get,
+			 hisi_ptt_set_trace_buf_nums_set, "%llu\n");
+
+static int hisi_ptt_set_trace_buflet_size_show(struct seq_file *m, void *v)
+{
+	struct hisi_ptt *hisi_ptt = m->private;
+	struct hisi_ptt_trace_ctrl *ctrl = &hisi_ptt->trace_ctrl;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(available_buflet_size); ++i) {
+		bool selected = false;
+
+		if (ctrl->buflet_size == available_buflet_size[i])
+			selected = true;
+
+		seq_printf(m, "%s%uMiB%s  ",
+			   selected ? "[" : "", available_buflet_size[i] >> 20,
+			   selected ? "]" : "");
+	}
+	seq_putc(m, '\n');
+
+	return 0;
+}
+
+static ssize_t hisi_ptt_set_trace_buflet_size_write(struct file *filp,
+						    const char __user *buf,
+						    size_t count, loff_t *pos)
+{
+	struct seq_file *m = filp->private_data;
+	struct hisi_ptt *hisi_ptt = m->private;
+	struct hisi_ptt_trace_ctrl *ctrl = &hisi_ptt->trace_ctrl;
+	char tbuf[HISI_PTT_CTRL_STR_LEN];
+	unsigned int size;
+	int i;
+
+	if (hisi_ptt_write_to_buffer(tbuf, HISI_PTT_CTRL_STR_LEN - 1,
+				     pos, buf, count))
+		return -EINVAL;
+
+	if (kstrtouint(tbuf, 0, &size))
+		return -EINVAL;
+
+	size <<= 20;
+	for (i = 0; i < ARRAY_SIZE(available_buflet_size); ++i) {
+		if (available_buflet_size[i] == size) {
+			ctrl->buflet_size = size;
+			return count;
+		}
+	}
+
+	return -EINVAL;
+}
+HISI_PTT_TRACE_ATTR(hisi_ptt_set_trace_buflet_size);
+
+static int hisi_ptt_free_trace_buf_get(void *data, u64 *val)
+{
+	struct hisi_ptt_debugfs_file_desc *desc = data;
+	struct hisi_ptt *hisi_ptt = desc->hisi_ptt;
+
+	if (!mutex_trylock(&hisi_ptt->mutex))
+		return -EBUSY;
+
+	*val = list_empty(&hisi_ptt->trace_ctrl.trace_buf);
+
+	mutex_unlock(&hisi_ptt->mutex);
+	return 0;
+}
+
+static int hisi_ptt_free_trace_buf_set(void *data, u64 val)
+{
+	struct hisi_ptt_debugfs_file_desc *desc = data;
+	struct hisi_ptt *hisi_ptt = desc->hisi_ptt;
+	int ret = 0;
+
+	if (!mutex_trylock(&hisi_ptt->mutex))
+		return -EBUSY;
+
+	if (!list_empty(&hisi_ptt->trace_ctrl.trace_buf)) {
+		if (hisi_ptt->trace_ctrl.status == HISI_PTT_TRACE_STATUS_ON)
+			ret = -EBUSY;
+		else
+			hisi_ptt_free_trace_buf(hisi_ptt);
+	}
+
+	mutex_unlock(&hisi_ptt->mutex);
+	return ret;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(hisi_ptt_free_trace_buf_fops,
+			 hisi_ptt_free_trace_buf_get,
+			 hisi_ptt_free_trace_buf_set, "%llu\n");
+
+static int hisi_ptt_trace_data_format_show(struct seq_file *m, void *v)
+{
+	struct hisi_ptt *hisi_ptt = m->private;
+	struct hisi_ptt_trace_ctrl *ctrl = &hisi_ptt->trace_ctrl;
+
+	seq_printf(m, "%s\n", ctrl->tr_format ? "4DW [8DW]" : "[4DW] 8DW");
+
+	return 0;
+}
+
+static ssize_t hisi_ptt_trace_data_format_write(struct file *filp,
+						const char __user *buf,
+						size_t count, loff_t *pos)
+{
+	struct seq_file *m = filp->private_data;
+	struct hisi_ptt *hisi_ptt = m->private;
+	struct hisi_ptt_trace_ctrl *ctrl = &hisi_ptt->trace_ctrl;
+	char tbuf[HISI_PTT_CTRL_STR_LEN];
+	u32 format;
+
+	if (hisi_ptt_write_to_buffer(tbuf, HISI_PTT_CTRL_STR_LEN - 1,
+				     pos, buf, count))
+		return -EINVAL;
+
+	if (kstrtouint(tbuf, 0, &format))
+		return -EINVAL;
+
+	/* The data format can only be 4DW or 8DW */
+	if (format == 4)
+		ctrl->tr_format = HISI_PTT_TRACE_DATA_4DW;
+	else if (format == 8)
+		ctrl->tr_format = HISI_PTT_TRACE_DATA_8DW;
+	else
+		return -EINVAL;
+
+	return count;
+}
+HISI_PTT_TRACE_ATTR(hisi_ptt_trace_data_format);
+
+static void *hisi_ptt_trace_data_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	struct hisi_ptt *hisi_ptt = m->private;
+	struct hisi_ptt_dma_buflet *buflet = v;
+
+	(*pos)++;
+
+	if (!list_is_last(&buflet->list, &hisi_ptt->trace_ctrl.trace_buf))
+		return list_next_entry(buflet, list);
+
+	return NULL;
+}
+
+static void *hisi_ptt_trace_data_start(struct seq_file *m, loff_t *pos)
+{
+	struct hisi_ptt *hisi_ptt = m->private;
+	struct hisi_ptt_dma_buflet *buflet;
+	loff_t off = 0;
+
+	buflet = list_first_entry(&hisi_ptt->trace_ctrl.trace_buf,
+				  struct hisi_ptt_dma_buflet, list);
+	while (off < *pos)
+		buflet = hisi_ptt_trace_data_next(m, buflet, &off);
+
+	return buflet;
+}
+
+static void hisi_ptt_trace_data_stop(struct seq_file *m, void *p)
+{
+	/* Nothing to do, only a stub */
+}
+
+static int hisi_ptt_trace_data_show(struct seq_file *m, void *v)
+{
+	struct hisi_ptt_dma_buflet *buflet = v;
+
+	if (buflet)
+		seq_write(m, buflet->addr, buflet->size);
+
+	return 0;
+}
+
+/*
+ * The operations of the seq_file will exist when the mutex of
+ * hisi_ptt being held in the open(), and the mutex will be
+ * released in the release().
+ */
+static const struct seq_operations hisi_ptt_trace_data_seq_ops = {
+	.start	= hisi_ptt_trace_data_start,
+	.next	= hisi_ptt_trace_data_next,
+	.stop	= hisi_ptt_trace_data_stop,
+	.show	= hisi_ptt_trace_data_show,
+};
+
+static int hisi_ptt_trace_data_open(struct inode *inode, struct file *filep)
+{
+	struct hisi_ptt_debugfs_file_desc *desc = inode->i_private;
+	struct hisi_ptt *hisi_ptt = desc->hisi_ptt;
+	struct seq_file *m;
+	int ret;
+
+	if (!mutex_trylock(&hisi_ptt->mutex))
+		return -EBUSY;
+
+	/*
+	 * Check the trace status, we cannot read the
+	 * data if the trace is still on. Then hold the
+	 * lock when reading the traced data.
+	 */
+	if (hisi_ptt->trace_ctrl.status == HISI_PTT_TRACE_STATUS_ON ||
+	    hisi_ptt_wait_trace_hw_idle(hisi_ptt)) {
+		ret = -EBUSY;
+		goto err;
+	}
+
+	if (list_empty(&hisi_ptt->trace_ctrl.trace_buf)) {
+		pci_info(hisi_ptt->pdev, "the trace buffer is empty\n");
+		ret = -ENOTTY;
+		goto err;
+	}
+
+	ret = seq_open(filep, &hisi_ptt_trace_data_seq_ops);
+	if (ret)
+		goto err;
+
+	m = filep->private_data;
+	m->private = hisi_ptt;
+
+	return 0;
+
+err:
+	mutex_unlock(&hisi_ptt->mutex);
+	return ret;
+}
+
+static ssize_t hisi_ptt_trace_data_write(struct file *filp,
+					 const char __user *buf,
+					 size_t count, loff_t *off)
+{
+	struct seq_file *m = filp->private_data;
+	struct hisi_ptt *hisi_ptt = m->private;
+	char tbuf[HISI_PTT_CTRL_STR_LEN];
+
+	if (hisi_ptt_write_to_buffer(tbuf, HISI_PTT_CTRL_STR_LEN - 1,
+				     off, buf, count))
+		return -EINVAL;
+
+	/* Free the trace buffer when `echo "" > trace_data` */
+	if (!strlen(tbuf) && !list_empty(&hisi_ptt->trace_ctrl.trace_buf)) {
+		if (hisi_ptt->trace_ctrl.status == HISI_PTT_TRACE_STATUS_ON)
+			return -EBUSY;
+		hisi_ptt_free_trace_buf(hisi_ptt);
+	}
+
+	return count;
+}
+
+static int hisi_ptt_trace_data_release(struct inode *inode, struct file *filp)
+{
+	struct hisi_ptt_debugfs_file_desc *desc = inode->i_private;
+	struct hisi_ptt *hisi_ptt = desc->hisi_ptt;
+
+	mutex_unlock(&hisi_ptt->mutex);
+
+	return seq_release(inode, filp);
+}
+
+static const struct file_operations hisi_ptt_trace_data_fops = {
+	.owner		= THIS_MODULE,
+	.open		= hisi_ptt_trace_data_open,
+	.read		= seq_read,
+	.write		= hisi_ptt_trace_data_write,
+	.llseek		= no_llseek,
+	.release	= hisi_ptt_trace_data_release,
+};
+
+static struct hisi_ptt_debugfs_file_desc trace_entries[] = {
+	PTT_FILE_INIT("filter",		&hisi_ptt_set_filter_fops),
+	PTT_FILE_INIT("direction",	&hisi_ptt_set_direction_fops),
+	PTT_FILE_INIT("type",		&hisi_ptt_set_trace_type_fops),
+	PTT_FILE_INIT("data_format",	&hisi_ptt_trace_data_format_fops),
+	PTT_FILE_INIT("trace_on",	&hisi_ptt_trace_on_fops),
+	PTT_FILE_INIT("buf_nums",	&hisi_ptt_set_trace_buf_nums_fops),
+	PTT_FILE_INIT("buflet_size",	&hisi_ptt_set_trace_buflet_size_fops),
+	PTT_FILE_INIT("free_buffer",	&hisi_ptt_free_trace_buf_fops),
+	PTT_FILE_INIT("data",		&hisi_ptt_trace_data_fops),
+};
+
+static irqreturn_t hisi_ptt_isr(int irq, void *context)
+{
+	struct hisi_ptt *hisi_ptt = context;
+	struct hisi_ptt_dma_buflet *next, *cur;
+	u32 status, val, buf_idx;
+
+	status = readl(hisi_ptt->iobase + HISI_PTT_TRACE_INT_STAT);
+	buf_idx = fls(status) - 1;
+
+	/*
+	 * Check whether the trace buffer is full. Stop tracing
+	 * when the last DMA buffer is finished. Otherwise, assign
+	 * the address of next buflet to the DMA register.
+	 */
+	cur = hisi_ptt->trace_ctrl.cur;
+	if (list_is_last(&cur->list, &hisi_ptt->trace_ctrl.trace_buf)) {
+		if ((status & HISI_PTT_TRACE_INT_STAT_MASK) ==
+		    HISI_PTT_TRACE_INT_STAT_MASK)
+			hisi_ptt_trace_end(hisi_ptt);
+
+		val = readl(hisi_ptt->iobase + HISI_PTT_TRACE_INT_MASK_REG);
+		val |= BIT(buf_idx);
+		writel(val, hisi_ptt->iobase + HISI_PTT_TRACE_INT_MASK_REG);
+	} else {
+		next = list_next_entry(cur, list);
+		writel(lower_32_bits(next->dma), hisi_ptt->iobase +
+				  HISI_PTT_TRACE_ADDR_BASE_LO_0 +
+				  buf_idx * HISI_PTT_TRACE_ADDR_STRIDE);
+		writel(upper_32_bits(next->dma), hisi_ptt->iobase +
+					HISI_PTT_TRACE_ADDR_BASE_HI_0 +
+					buf_idx * HISI_PTT_TRACE_ADDR_STRIDE);
+		hisi_ptt->trace_ctrl.cur = next;
+		val = BIT(buf_idx);
+		writel(val, hisi_ptt->iobase + HISI_PTT_TRACE_INT_STAT);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t hisi_ptt_irq(int irq, void *context)
+{
+	struct hisi_ptt *hisi_ptt = context;
+	u32 status;
+
+	status = readl(hisi_ptt->iobase + HISI_PTT_TRACE_INT_STAT);
+	if (status & HISI_PTT_TRACE_INT_STAT_MASK)
+		return IRQ_WAKE_THREAD;
+
+	return IRQ_NONE;
+}
+
+static int hisi_ptt_irq_register(struct hisi_ptt *hisi_ptt)
+{
+	struct pci_dev *pdev = hisi_ptt->pdev;
+	int ret;
+
+	ret = pci_alloc_irq_vectors(pdev, HISI_PTT_IRQ_NUMS, HISI_PTT_IRQ_NUMS,
+				    PCI_IRQ_MSI);
+	if (ret < 0) {
+		pci_err(pdev, "failed to allocate irq vector, ret = %d\n", ret);
+		return ret;
+	}
+
+	ret = request_threaded_irq(pci_irq_vector(pdev, HISI_PTT_DMA_IRQ),
+				   hisi_ptt_irq, hisi_ptt_isr, IRQF_SHARED,
+				   "hisi-ptt", hisi_ptt);
+	if (ret) {
+		pci_err(pdev, "failed to request irq %d, ret = %d\n",
+			pci_irq_vector(pdev, HISI_PTT_DMA_IRQ), ret);
+		pci_free_irq_vectors(pdev);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void hisi_ptt_irq_unregister(struct hisi_ptt *hisi_ptt)
+{
+	struct pci_dev *pdev = hisi_ptt->pdev;
+
+	free_irq(pci_irq_vector(pdev, HISI_PTT_DMA_IRQ), hisi_ptt);
+	pci_free_irq_vectors(pdev);
+}
+
+static void hisi_ptt_update_filters(struct work_struct *work)
+{
+	struct delayed_work *delayed_work = to_delayed_work(work);
+	struct hisi_ptt_filter_update_info info;
+	struct hisi_ptt_filter_desc *filter;
+	struct list_head *target_list;
+	struct hisi_ptt *hisi_ptt;
+
+	hisi_ptt = container_of(delayed_work, struct hisi_ptt, work);
+
+	if (!mutex_trylock(&hisi_ptt->mutex)) {
+		schedule_delayed_work(&hisi_ptt->work, HISI_PTT_WORK_DELAY_MS);
+		return;
+	}
+
+	while (kfifo_get(&hisi_ptt->filter_update_kfifo, &info)) {
+		target_list = info.is_port ? &hisi_ptt->port_filters :
+			      &hisi_ptt->req_filters;
+
+		if (info.is_add) {
+			filter = kzalloc(sizeof(*filter), GFP_KERNEL);
+			if (!filter) {
+				pci_err(hisi_ptt->pdev,
+					"failed to update the filters\n");
+				continue;
+			}
+
+			filter->pdev = info.pdev;
+			filter->val = info.val;
+
+			list_add_tail(&filter->list, target_list);
+		} else {
+			list_for_each_entry(filter, target_list, list)
+				if (filter->val == info.val) {
+					list_del(&filter->list);
+					kfree(filter);
+					break;
+				}
+		}
+	}
+
+	mutex_unlock(&hisi_ptt->mutex);
+}
+
+static void hisi_ptt_update_fifo_in(struct hisi_ptt *hisi_ptt,
+				    struct hisi_ptt_filter_update_info *info)
+{
+	struct pci_dev *root_port = pcie_find_root_port(info->pdev);
+
+	if (!root_port)
+		return;
+
+	info->port_devid = PCI_DEVID(root_port->bus->number, root_port->devfn);
+	if (info->port_devid < hisi_ptt->lower ||
+	    info->port_devid > hisi_ptt->upper)
+			return;
+
+	info->is_port = pci_pcie_type(info->pdev) == PCI_EXP_TYPE_ROOT_PORT;
+	info->val = hisi_ptt_get_filter_val(info->pdev);
+
+	if (kfifo_in_spinlocked(&hisi_ptt->filter_update_kfifo, info, 1,
+				&hisi_ptt->filter_update_lock))
+		schedule_delayed_work(&hisi_ptt->work, 0);
+	else
+		pci_warn(hisi_ptt->pdev,
+			 "filter update fifo overflow for target %s\n",
+			 pci_name(info->pdev));
+}
+
+/*
+ * A PCI bus notifier is used here for dynamically updating the filter
+ * list.
+ */
+static int hisi_ptt_notifier_call(struct notifier_block *nb,
+				  unsigned long action,
+				  void *data)
+{
+	struct hisi_ptt *hisi_ptt = container_of(nb, struct hisi_ptt, hisi_ptt_nb);
+	struct hisi_ptt_filter_update_info info;
+	struct device *dev = data;
+	struct pci_dev *pdev = to_pci_dev(dev);
+
+	info.pdev = pdev;
+
+	switch (action) {
+	case BUS_NOTIFY_ADD_DEVICE:
+		info.is_add = true;
+		break;
+	case BUS_NOTIFY_DEL_DEVICE:
+		info.is_add = false;
+		break;
+	default:
+		return 0;
+	}
+
+	hisi_ptt_update_fifo_in(hisi_ptt, &info);
+
+	return 0;
+}
+
+static int hisi_ptt_init_filters(struct pci_dev *pdev, void *data)
+{
+	struct hisi_ptt_filter_update_info info = {
+		.pdev = pdev,
+		.is_add = true,
+	};
+	struct hisi_ptt *hisi_ptt = data;
+
+	hisi_ptt_update_fifo_in(hisi_ptt, &info);
+
+	return 0;
+}
+
+static void hisi_ptt_release_filters(struct hisi_ptt *hisi_ptt)
+{
+	struct hisi_ptt_filter_desc *filter, *tfilter;
+
+	list_for_each_entry_safe(filter, tfilter, &hisi_ptt->req_filters, list) {
+		list_del(&filter->list);
+		kfree(filter);
+	}
+
+	list_for_each_entry_safe(filter, tfilter, &hisi_ptt->port_filters, list) {
+		list_del(&filter->list);
+		kfree(filter);
+	}
+}
+
+static void hisi_ptt_init_ctrls(struct hisi_ptt *hisi_ptt)
+{
+	struct pci_bus *bus;
+	u32 reg;
+
+	INIT_LIST_HEAD(&hisi_ptt->port_filters);
+	INIT_LIST_HEAD(&hisi_ptt->req_filters);
+
+	/*
+	 * The device range register provides the information about the
+	 * root ports which the RCiEP can control and trace. The RCiEP
+	 * and the root ports it support are on the same PCIe core, with
+	 * same domain number but maybe different bus number. The device
+	 * range register will tell us which root ports we can support,
+	 * Bit[31:16] indicates the upper BDF numbers of the root port,
+	 * while Bit[15:0] indicates the lower.
+	 */
+	reg = readl(hisi_ptt->iobase + HISI_PTT_DEVICE_RANGE);
+	hisi_ptt->upper = reg >> 16;
+	hisi_ptt->lower = reg & 0xffff;
+
+	bus = pci_find_bus(pci_domain_nr(hisi_ptt->pdev->bus),
+			   PCI_BUS_NUM(hisi_ptt->upper));
+	if (bus)
+		pci_walk_bus(bus, hisi_ptt_init_filters, hisi_ptt);
+
+	/* Initialize trace controls */
+	INIT_LIST_HEAD(&hisi_ptt->trace_ctrl.trace_buf);
+	hisi_ptt->trace_ctrl.buflet_nums = HISI_PTT_DEFAULT_TRACE_BUF_CNT;
+	hisi_ptt->trace_ctrl.buflet_size = HISI_PTT_TRACE_DEFAULT_BUFLET_SIZE;
+	hisi_ptt->trace_ctrl.rxtx = HISI_PTT_TRACE_DEFAULT_RXTX.event_code;
+	hisi_ptt->trace_ctrl.tr_event = HISI_PTT_TRACE_DEFAULT_EVENT.event_code;
+}
+
+static int hisi_ptt_create_trace_entries(struct hisi_ptt *hisi_ptt)
+{
+	struct hisi_ptt_debugfs_file_desc *trace_files;
+	struct dentry *dir;
+	int i, ret = 0;
+
+	dir = debugfs_create_dir("trace", hisi_ptt->debugfs_dir);
+	if (IS_ERR(dir))
+		return PTR_ERR(dir);
+
+	trace_files = devm_kmemdup(&hisi_ptt->pdev->dev, trace_entries,
+				   sizeof(trace_entries), GFP_KERNEL);
+	if (IS_ERR(trace_files)) {
+		ret = PTR_ERR(trace_files);
+		goto err;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(trace_entries); ++i) {
+		struct dentry *file;
+
+		trace_files[i].hisi_ptt = hisi_ptt;
+		file = debugfs_create_file(trace_files[i].name, 0600,
+					   dir, &trace_files[i],
+					   trace_files[i].fops);
+		if (IS_ERR(file)) {
+			ret = PTR_ERR(file);
+			goto err;
+		}
+	}
+
+	return 0;
+
+err:
+	debugfs_remove_recursive(dir);
+	return ret;
+}
+
+static int hisi_ptt_create_debugfs_entries(struct hisi_ptt *hisi_ptt)
+{
+	int ret;
+
+	hisi_ptt->debugfs_dir = debugfs_create_dir(hisi_ptt->name,
+						   hisi_ptt_debugfs_root);
+	if (IS_ERR(hisi_ptt->debugfs_dir))
+		return PTR_ERR(hisi_ptt->debugfs_dir);
+
+	ret = hisi_ptt_create_trace_entries(hisi_ptt);
+	if (ret) {
+		pci_err(hisi_ptt->pdev, "failed to create debugfs entries\n");
+		debugfs_remove_recursive(hisi_ptt->debugfs_dir);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int hisi_ptt_probe(struct pci_dev *pdev,
+			  const struct pci_device_id *id)
+{
+	struct hisi_ptt *hisi_ptt;
+	int ret;
+
+	hisi_ptt = devm_kzalloc(&pdev->dev, sizeof(*hisi_ptt), GFP_KERNEL);
+	if (!hisi_ptt)
+		return -ENOMEM;
+
+	mutex_init(&hisi_ptt->mutex);
+	hisi_ptt->pdev = pdev;
+
+	/*
+	 * Lifetime of pci_dev is longer than hisi_ptt,
+	 * so directly reference to the pci name string.
+	 */
+	hisi_ptt->name = pci_name(pdev);
+	pci_set_drvdata(pdev, hisi_ptt);
+
+	ret = pcim_enable_device(pdev);
+	if (ret) {
+		pci_err(pdev, "failed to enable device, ret = %d\n", ret);
+		return ret;
+	}
+
+	ret = pcim_iomap_regions(pdev, BIT(2), hisi_ptt->name);
+	if (ret) {
+		pci_err(pdev, "failed to remap io memory, ret = %d\n", ret);
+		return ret;
+	}
+
+	hisi_ptt->iobase = pcim_iomap_table(pdev)[2];
+
+	ret = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(64));
+	if (ret) {
+		pci_err(pdev, "failed to set 64 bit dma mask, ret = %d\n", ret);
+		return ret;
+	}
+
+	pci_set_master(pdev);
+	ret = hisi_ptt_irq_register(hisi_ptt);
+	if (ret)
+		return ret;
+
+	spin_lock_init(&hisi_ptt->filter_update_lock);
+	INIT_DELAYED_WORK(&hisi_ptt->work, hisi_ptt_update_filters);
+	INIT_KFIFO(hisi_ptt->filter_update_kfifo);
+
+	hisi_ptt_init_ctrls(hisi_ptt);
+
+	ret = hisi_ptt_create_debugfs_entries(hisi_ptt);
+	if (ret) {
+		hisi_ptt_irq_unregister(hisi_ptt);
+		return ret;
+	}
+
+	/* Register the bus notifier for dynamically updating the filter list */
+	hisi_ptt->hisi_ptt_nb.notifier_call = hisi_ptt_notifier_call;
+	ret = bus_register_notifier(&pci_bus_type, &hisi_ptt->hisi_ptt_nb);
+	if (ret)
+		pci_warn(pdev, "failed to register notifier block, filter list cannot be updated dynamically\n");
+
+	return 0;
+}
+
+void hisi_ptt_remove(struct pci_dev *pdev)
+{
+	struct hisi_ptt *hisi_ptt = pci_get_drvdata(pdev);
+
+	bus_unregister_notifier(&pci_bus_type, &hisi_ptt->hisi_ptt_nb);
+	debugfs_remove_recursive(hisi_ptt->debugfs_dir);
+
+	/* Cancel any work that has been queued */
+	cancel_delayed_work_sync(&hisi_ptt->work);
+
+	/* Make sure trace is ended before free trace buffer */
+	if (hisi_ptt->trace_ctrl.status == HISI_PTT_TRACE_STATUS_ON)
+		hisi_ptt_trace_end(hisi_ptt);
+
+	hisi_ptt_release_filters(hisi_ptt);
+	hisi_ptt_free_trace_buf(hisi_ptt);
+	hisi_ptt_irq_unregister(hisi_ptt);
+}
+
+static const struct pci_device_id hisi_ptt_id_tbl[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_HUAWEI, 0xa12e) },
+	{ }
+};
+MODULE_DEVICE_TABLE(pci, hisi_ptt_id_tbl);
+
+static struct pci_driver hisi_ptt_driver = {
+	.name = "hisi_ptt",
+	.id_table = hisi_ptt_id_tbl,
+	.probe = hisi_ptt_probe,
+	.remove = hisi_ptt_remove,
+};
+
+static int hisi_ptt_register_debugfs(void)
+{
+	if (!debugfs_initialized()) {
+		pr_err("failed to create debugfs directory: debugfs uninitialized\n");
+		return -ENOENT;
+	}
+
+	hisi_ptt_debugfs_root = debugfs_create_dir("hisi_ptt", NULL);
+	if (IS_ERR(hisi_ptt_debugfs_root)) {
+		pr_err("failed to create debugfs directory.\n");
+		return PTR_ERR(hisi_ptt_debugfs_root);
+	}
+
+	return 0;
+}
+
+static void hisi_ptt_unregister_debugfs(void)
+{
+	debugfs_remove_recursive(hisi_ptt_debugfs_root);
+}
+
+static int __init hisi_ptt_module_init(void)
+{
+	int ret;
+
+	/* The driver cannot work without debugfs entry */
+	ret = hisi_ptt_register_debugfs();
+	if (ret)
+		return ret;
+
+	ret = pci_register_driver(&hisi_ptt_driver);
+	if (ret) {
+		pr_err("failed to register hisi ptt driver, ret = %d.\n", ret);
+		hisi_ptt_unregister_debugfs();
+		return ret;
+	}
+
+	return 0;
+}
+
+static void __exit hisi_ptt_module_exit(void)
+{
+	pci_unregister_driver(&hisi_ptt_driver);
+	hisi_ptt_unregister_debugfs();
+}
+
+module_init(hisi_ptt_module_init);
+module_exit(hisi_ptt_module_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Yicong Yang <yangyicong@xxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Driver for HiSilicon PCIe tune and trace device");
-- 
2.8.1