[PATCH 1/1] usb: xhci: Add debugfs interface for xHCI driver

[PATCH 1/1] usb: xhci: Add debugfs interface for xHCI driver

[Lu Baolu]

This adds debugfs consumer for xHCI driver. The debugfs entries
read all host registers, device/endpoint contexts, command ring,
event ring and various endpoint rings. With these entries, users
can check the registers and memory spaces used by a host during
run time, or save all the information with a simple 'cp -r' for
post-mortem programs.

The file hierarchy looks like this.

[root of debugfs]
|__usb
|____[e,u,o]hci                 <---------[root for other HCIs]
|____xhci                       <---------------[root for xHCI]
|______0000:00:14.0             <--------------[xHCI host name]
|________reg-cap                <--------[capability registers]
|________reg-op                 <-------[operational registers]
|________reg-runtime            <-----------[runtime registers]
|________reg-ext-#cap_name      <----[extended capability regs]
|________command-ring           <-------[root for command ring]
|__________cycle                <------------------[ring cycle]
|__________dequeue              <--------[ring dequeue pointer]
|__________enqueue              <--------[ring enqueue pointer]
|__________trbs                 <-------------------[ring trbs]
|________event-ring             <---------[root for event ring]
|__________cycle                <------------------[ring cycle]
|__________dequeue              <--------[ring dequeue pointer]
|__________enqueue              <--------[ring enqueue pointer]
|__________trbs                 <-------------------[ring trbs]
|________devices                <------------[root for devices]
|__________#slot_id             <-----------[root for a device]
|____________name               <-----------------[device name]
|____________slot-context       <----------------[slot context]
|____________ep-context         <-----------[endpoint contexts]
|____________ep#ep_index        <--------[root for an endpoint]
|______________cycle            <------------------[ring cycle]
|______________dequeue          <--------[ring dequeue pointer]
|______________enqueue          <--------[ring enqueue pointer]
|______________trbs             <-------------------[ring trbs]

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/usb/host/Makefile       |   4 +
 drivers/usb/host/xhci-debugfs.c | 552 ++++++++++++++++++++++++++++++++++++++++
 drivers/usb/host/xhci-debugfs.h | 137 ++++++++++
 drivers/usb/host/xhci-mem.c     |   4 +-
 drivers/usb/host/xhci.c         |  21 +-
 drivers/usb/host/xhci.h         |   9 +
 6 files changed, 723 insertions(+), 4 deletions(-)
 create mode 100644 drivers/usb/host/xhci-debugfs.c
 create mode 100644 drivers/usb/host/xhci-debugfs.h

diff --git a/drivers/usb/host/Makefile b/drivers/usb/host/Makefile
index cf2691f..b2a7f05 100644
--- a/drivers/usb/host/Makefile
+++ b/drivers/usb/host/Makefile
@@ -25,6 +25,10 @@ ifneq ($(CONFIG_USB_XHCI_RCAR), )
 	xhci-plat-hcd-y		+= xhci-rcar.o
 endif
 
+ifneq ($(CONFIG_DEBUG_FS),)
+	xhci-hcd-y		+= xhci-debugfs.o
+endif
+
 obj-$(CONFIG_USB_WHCI_HCD)	+= whci/
 
 obj-$(CONFIG_USB_PCI)	+= pci-quirks.o
diff --git a/drivers/usb/host/xhci-debugfs.c b/drivers/usb/host/xhci-debugfs.c
new file mode 100644
index 0000000..7588ac6
--- /dev/null
+++ b/drivers/usb/host/xhci-debugfs.c
@@ -0,0 +1,552 @@
+/*
+ * xhci-debugfs.c - xHCI debugfs interface
+ *
+ * Copyright (C) 2017 Intel Corporation
+ *
+ * Author: Lu Baolu <baolu.lu@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/slab.h>
+
+#include "xhci.h"
+#include "xhci-debugfs.h"
+
+static const struct debugfs_reg32 xhci_cap_regs[] = {
+	dump_register(CAPLENGTH),
+	dump_register(HCSPARAMS1),
+	dump_register(HCSPARAMS2),
+	dump_register(HCSPARAMS3),
+	dump_register(HCCPARAMS1),
+	dump_register(DOORBELLOFF),
+	dump_register(RUNTIMEOFF),
+	dump_register(HCCPARAMS2),
+};
+
+static const struct debugfs_reg32 xhci_op_regs[] = {
+	dump_register(USBCMD),
+	dump_register(USBSTS),
+	dump_register(PAGESIZE),
+	dump_register(DNCTRL),
+	dump_register(CRCR),
+	dump_register(DCBAAP_LOW),
+	dump_register(DCBAAP_HIGH),
+	dump_register(CONFIG),
+};
+
+static const struct debugfs_reg32 xhci_runtime_regs[] = {
+	dump_register(MFINDEX),
+	dump_register(IR0_IMAN),
+	dump_register(IR0_IMOD),
+	dump_register(IR0_ERSTSZ),
+	dump_register(IR0_ERSTBA_LOW),
+	dump_register(IR0_ERSTBA_HIGH),
+	dump_register(IR0_ERDP_LOW),
+	dump_register(IR0_ERDP_HIGH),
+};
+
+static const struct debugfs_reg32 xhci_extcap_legsup[] = {
+	dump_register(EXTCAP_USBLEGSUP),
+	dump_register(EXTCAP_USBLEGCTLSTS),
+};
+
+static const struct debugfs_reg32 xhci_extcap_protocol[] = {
+	dump_register(EXTCAP_REVISION),
+	dump_register(EXTCAP_NAME),
+	dump_register(EXTCAP_PORTINFO),
+	dump_register(EXTCAP_PORTTYPE),
+	dump_register(EXTCAP_MANTISSA1),
+	dump_register(EXTCAP_MANTISSA2),
+	dump_register(EXTCAP_MANTISSA3),
+	dump_register(EXTCAP_MANTISSA4),
+	dump_register(EXTCAP_MANTISSA5),
+	dump_register(EXTCAP_MANTISSA6),
+};
+
+static const struct debugfs_reg32 xhci_extcap_dbc[] = {
+	dump_register(EXTCAP_DBC_CAPABILITY),
+	dump_register(EXTCAP_DBC_DOORBELL),
+	dump_register(EXTCAP_DBC_ERSTSIZE),
+	dump_register(EXTCAP_DBC_ERST_LOW),
+	dump_register(EXTCAP_DBC_ERST_HIGH),
+	dump_register(EXTCAP_DBC_ERDP_LOW),
+	dump_register(EXTCAP_DBC_ERDP_HIGH),
+	dump_register(EXTCAP_DBC_CONTROL),
+	dump_register(EXTCAP_DBC_STATUS),
+	dump_register(EXTCAP_DBC_PORTSC),
+	dump_register(EXTCAP_DBC_CONT_LOW),
+	dump_register(EXTCAP_DBC_CONT_HIGH),
+	dump_register(EXTCAP_DBC_DEVINFO1),
+	dump_register(EXTCAP_DBC_DEVINFO2),
+};
+
+static struct dentry *xhci_debugfs_root;
+
+static struct xhci_regset *xhci_debugfs_alloc_regset(struct xhci_hcd *xhci)
+{
+	struct xhci_regset	*regset;
+
+	regset = kzalloc(sizeof(*regset), GFP_KERNEL);
+	if (!regset)
+		return NULL;
+
+	/*
+	 * The allocation and free of regset are executed in order.
+	 * We needn't a lock here.
+	 */
+	INIT_LIST_HEAD(&regset->list);
+	list_add_tail(&regset->list, &xhci->regset_list);
+
+	return regset;
+}
+
+static void xhci_debugfs_free_regset(struct xhci_regset *regset)
+{
+	if (!regset)
+		return;
+
+	list_del(&regset->list);
+	kfree(regset);
+}
+
+static int xhci_debugfs_regset(struct xhci_hcd *xhci, u32 base,
+			       const struct debugfs_reg32 *regs,
+			       size_t nregs, struct dentry *parent,
+			       const char *fmt, ...)
+{
+	struct xhci_regset	*rgs;
+	va_list			args;
+	struct debugfs_regset32	*regset;
+	struct dentry		*regdump;
+	struct usb_hcd		*hcd = xhci_to_hcd(xhci);
+
+	rgs = xhci_debugfs_alloc_regset(xhci);
+	if (!rgs)
+		return -ENOMEM;
+
+	va_start(args, fmt);
+	vsnprintf(rgs->name, sizeof(rgs->name), fmt, args);
+	va_end(args);
+
+	regset = &rgs->regset;
+	regset->regs = regs;
+	regset->nregs = nregs;
+	regset->base = hcd->regs + base;
+
+	regdump = debugfs_create_regset32((const char *)rgs->name,
+					  0444, parent, regset);
+
+	return regdump ? 0 : -ENOMEM;
+}
+
+static int xhci_debugfs_extcap_regset(struct xhci_hcd *xhci, int cap_id,
+				      const struct debugfs_reg32 *regs,
+				      size_t n, const char *cap_name)
+{
+	int			index = 0;
+	u32			offset;
+	size_t			psic, nregs = n;
+	void __iomem		*base = &xhci->cap_regs->hc_capbase;
+
+	offset = xhci_find_next_ext_cap(base, 0, cap_id);
+	while (offset) {
+		if (cap_id == XHCI_EXT_CAPS_PROTOCOL) {
+			psic = XHCI_EXT_PORT_PSIC(readl(base + offset + 8));
+			nregs = min(4 + psic, n);
+		}
+
+		xhci_debugfs_regset(xhci, offset, regs, nregs,
+				    xhci->debugfs_root, "%s:%02d",
+				    cap_name, index);
+		offset = xhci_find_next_ext_cap(base, offset, cap_id);
+		index++;
+	}
+
+	return 0;
+}
+
+static int xhci_ring_enqueue_show(struct seq_file *s, void *unused)
+{
+	struct xhci_ring	*ring = s->private;
+	dma_addr_t		dma;
+
+	dma = xhci_trb_virt_to_dma(ring->enq_seg, ring->enqueue);
+	seq_printf(s, "%pad\n", &dma);
+
+	return 0;
+}
+
+static int xhci_ring_dequeue_show(struct seq_file *s, void *unused)
+{
+	struct xhci_ring	*ring = s->private;
+	dma_addr_t		dma;
+
+	dma = xhci_trb_virt_to_dma(ring->deq_seg, ring->dequeue);
+	seq_printf(s, "%pad\n", &dma);
+
+	return 0;
+}
+
+static int xhci_ring_cycle_show(struct seq_file *s, void *unused)
+{
+	struct xhci_ring	*ring = s->private;
+
+	seq_printf(s, "%d\n", ring->cycle_state);
+
+	return 0;
+}
+
+static void xhci_ring_dump_segment(struct seq_file *s,
+				   struct xhci_segment *seg)
+{
+	int			i;
+	dma_addr_t		dma;
+	union xhci_trb		*trb;
+
+	for (i = 0; i < TRBS_PER_SEGMENT; i++) {
+		trb = &seg->trbs[i];
+		dma = seg->dma + i * sizeof(*trb);
+		seq_printf(s, "%pad: %s\n", &dma,
+			   xhci_decode_trb(trb->generic.field[0],
+					   trb->generic.field[1],
+					   trb->generic.field[2],
+					   trb->generic.field[3]));
+	}
+}
+
+static int xhci_ring_trb_show(struct seq_file *s, void *unused)
+{
+	int			i;
+	struct xhci_ring	*ring = s->private;
+	struct xhci_segment	*seg = ring->first_seg;
+
+	for (i = 0; i < ring->num_segs; i++) {
+		xhci_ring_dump_segment(s, seg);
+		seg = seg->next;
+	}
+
+	return 0;
+}
+
+static struct xhci_file_map ring_files[] = {
+	{"enqueue",		xhci_ring_enqueue_show, },
+	{"dequeue",		xhci_ring_dequeue_show, },
+	{"cycle",		xhci_ring_cycle_show, },
+	{"trbs",		xhci_ring_trb_show, },
+};
+
+static int xhci_ring_open(struct inode *inode, struct file *file)
+{
+	int			i;
+	struct xhci_file_map	*f_map;
+	const char		*file_name = file_dentry(file)->d_iname;
+
+	for (i = 0; i < ARRAY_SIZE(ring_files); i++) {
+		f_map = &ring_files[i];
+
+		if (strcmp(f_map->name, file_name) == 0)
+			break;
+	}
+
+	return single_open(file, f_map->show, inode->i_private);
+}
+
+static const struct file_operations xhci_ring_fops = {
+	.open			= xhci_ring_open,
+	.read			= seq_read,
+	.llseek			= seq_lseek,
+	.release		= single_release,
+};
+
+static int xhci_slot_context_show(struct seq_file *s, void *unused)
+{
+	struct xhci_hcd		*xhci;
+	struct xhci_slot_ctx	*slot_ctx;
+	struct xhci_slot_priv	*priv = s->private;
+	struct xhci_virt_device	*dev = priv->dev;
+
+	xhci = hcd_to_xhci(bus_to_hcd(dev->udev->bus));
+	slot_ctx = xhci_get_slot_ctx(xhci, dev->out_ctx);
+	seq_printf(s, "%pad: %s\n", &dev->out_ctx->dma,
+		   xhci_decode_slot_context(slot_ctx->dev_info,
+					    slot_ctx->dev_info2,
+					    slot_ctx->tt_info,
+					    slot_ctx->dev_state));
+
+	return 0;
+}
+
+static int xhci_endpoint_context_show(struct seq_file *s, void *unused)
+{
+	int			dci;
+	dma_addr_t		dma;
+	struct xhci_hcd		*xhci;
+	struct xhci_ep_ctx	*ep_ctx;
+	struct xhci_slot_priv	*priv = s->private;
+	struct xhci_virt_device	*dev = priv->dev;
+
+	xhci = hcd_to_xhci(bus_to_hcd(dev->udev->bus));
+
+	for (dci = 1; dci < 32; dci++) {
+		ep_ctx = xhci_get_ep_ctx(xhci, dev->out_ctx, dci);
+		dma = dev->out_ctx->dma + dci * CTX_SIZE(xhci->hcc_params);
+		seq_printf(s, "%pad: %s\n", &dma,
+			   xhci_decode_ep_context(ep_ctx->ep_info,
+						  ep_ctx->ep_info2,
+						  ep_ctx->deq,
+						  ep_ctx->tx_info));
+	}
+
+	return 0;
+}
+
+static int xhci_device_name_show(struct seq_file *s, void *unused)
+{
+	struct xhci_slot_priv	*priv = s->private;
+	struct xhci_virt_device	*dev = priv->dev;
+
+	seq_printf(s, "%s\n", dev_name(&dev->udev->dev));
+
+	return 0;
+}
+
+static struct xhci_file_map context_files[] = {
+	{"name",		xhci_device_name_show, },
+	{"slot-context",	xhci_slot_context_show, },
+	{"ep-context",		xhci_endpoint_context_show, },
+};
+
+static int xhci_context_open(struct inode *inode, struct file *file)
+{
+	int			i;
+	struct xhci_file_map	*f_map;
+	const char		*file_name = file_dentry(file)->d_iname;
+
+	for (i = 0; i < ARRAY_SIZE(context_files); i++) {
+		f_map = &context_files[i];
+
+		if (strcmp(f_map->name, file_name) == 0)
+			break;
+	}
+
+	return single_open(file, f_map->show, inode->i_private);
+}
+
+static const struct file_operations xhci_context_fops = {
+	.open			= xhci_context_open,
+	.read			= seq_read,
+	.llseek			= seq_lseek,
+	.release		= single_release,
+};
+
+static void xhci_debugfs_create_files(struct xhci_hcd *xhci,
+				      struct xhci_file_map *files,
+				      size_t nentries, void *data,
+				      struct dentry *parent,
+				      const struct file_operations *fops)
+{
+	int			i;
+	struct dentry		*file;
+
+	for (i = 0; i < nentries; i++) {
+		file = debugfs_create_file(files[i].name, 0444,
+					   parent, data, fops);
+		if (IS_ERR_OR_NULL(file))
+			break;
+	}
+}
+
+static struct dentry *xhci_debugfs_create_ring_dir(struct xhci_hcd *xhci,
+						   struct xhci_ring *ring,
+						   const char *name,
+						   struct dentry *parent)
+{
+	struct dentry		*dir;
+
+	dir = debugfs_create_dir(name, parent);
+	if (IS_ERR_OR_NULL(dir))
+		return NULL;
+
+	xhci_debugfs_create_files(xhci, ring_files, ARRAY_SIZE(ring_files),
+				  ring, dir, &xhci_ring_fops);
+
+	return dir;
+}
+
+static void xhci_debugfs_create_context_files(struct xhci_hcd *xhci,
+					      struct dentry *parent,
+					      int slot_id)
+{
+	struct xhci_virt_device	*dev = xhci->devs[slot_id];
+
+	xhci_debugfs_create_files(xhci, context_files,
+				  ARRAY_SIZE(context_files),
+				  dev->debugfs_private,
+				  parent, &xhci_context_fops);
+}
+
+void xhci_debugfs_create_endpoint(struct xhci_hcd *xhci,
+				  struct xhci_virt_device *dev,
+				  int ep_index)
+{
+	struct dentry		*dir;
+	struct xhci_ep_priv	*epriv;
+	struct xhci_slot_priv	*spriv = dev->debugfs_private;
+
+	if (spriv->eps[ep_index])
+		return;
+
+	epriv = kzalloc(sizeof(*epriv), GFP_KERNEL);
+	if (!epriv)
+		return;
+
+	snprintf(epriv->name, sizeof(epriv->name), "ep%02d", ep_index);
+	dir = xhci_debugfs_create_ring_dir(xhci,
+					   dev->eps[ep_index].new_ring,
+					   epriv->name,
+					   spriv->root);
+	epriv->root = dir;
+	spriv->eps[ep_index] = epriv;
+}
+
+void xhci_debugfs_remove_endpoint(struct xhci_hcd *xhci,
+				  struct xhci_virt_device *dev,
+				  int ep_index)
+{
+	struct xhci_slot_priv	*spriv = dev->debugfs_private;
+	struct xhci_ep_priv	*epriv;
+
+	if (!spriv || !spriv->eps[ep_index])
+		return;
+
+	epriv = spriv->eps[ep_index];
+	debugfs_remove_recursive(epriv->root);
+	spriv->eps[ep_index] = NULL;
+	kfree(epriv);
+}
+
+void xhci_debugfs_create_slot(struct xhci_hcd *xhci, int slot_id)
+{
+	struct dentry		*dir;
+	struct xhci_slot_priv	*priv;
+	struct xhci_virt_device	*dev = xhci->devs[slot_id];
+
+	if (IS_ERR_OR_NULL(xhci->debugfs_slots))
+		return;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return;
+
+	snprintf(priv->name, sizeof(priv->name), "%02d", slot_id);
+	dir = debugfs_create_dir(priv->name, xhci->debugfs_slots);
+	if (IS_ERR_OR_NULL(dir))
+		return;
+
+	priv->root = dir;
+	priv->dev = dev;
+	dev->debugfs_private = priv;
+
+	xhci_debugfs_create_ring_dir(xhci, dev->eps[0].ring,
+				     "ep00", dir);
+
+	xhci_debugfs_create_context_files(xhci, dir, slot_id);
+}
+
+void xhci_debugfs_remove_slot(struct xhci_hcd *xhci, int slot_id)
+{
+	struct xhci_virt_device	*dev = xhci->devs[slot_id];
+	struct xhci_slot_priv	*priv;
+
+	if (!dev || !dev->debugfs_private)
+		return;
+
+	priv = dev->debugfs_private;
+
+	debugfs_remove_recursive(priv->root);
+	kfree(priv);
+	dev->debugfs_private = NULL;
+}
+
+void xhci_debugfs_init(struct xhci_hcd *xhci)
+{
+	struct dentry		*dir;
+	struct device		*dev = xhci_to_hcd(xhci)->self.controller;
+
+	dir = debugfs_create_dir(dev_name(dev), xhci_debugfs_root);
+	if (IS_ERR_OR_NULL(dir))
+		return;
+
+	xhci->debugfs_root = dir;
+	INIT_LIST_HEAD(&xhci->regset_list);
+
+	xhci_debugfs_regset(xhci,
+			    0,
+			    xhci_cap_regs, ARRAY_SIZE(xhci_cap_regs),
+			    xhci->debugfs_root, "reg-cap");
+
+	xhci_debugfs_regset(xhci,
+			    HC_LENGTH(readl(&xhci->cap_regs->hc_capbase)),
+			    xhci_op_regs, ARRAY_SIZE(xhci_op_regs),
+			    xhci->debugfs_root, "reg-op");
+
+	xhci_debugfs_regset(xhci,
+			    readl(&xhci->cap_regs->run_regs_off) & RTSOFF_MASK,
+			    xhci_runtime_regs, ARRAY_SIZE(xhci_runtime_regs),
+			    xhci->debugfs_root, "reg-runtime");
+
+	xhci_debugfs_extcap_regset(xhci, XHCI_EXT_CAPS_LEGACY,
+				   xhci_extcap_legsup,
+				   ARRAY_SIZE(xhci_extcap_legsup),
+				   "reg-ext-legsup");
+
+	xhci_debugfs_extcap_regset(xhci, XHCI_EXT_CAPS_PROTOCOL,
+				   xhci_extcap_protocol,
+				   ARRAY_SIZE(xhci_extcap_protocol),
+				   "reg-ext-protocol");
+
+	xhci_debugfs_extcap_regset(xhci, XHCI_EXT_CAPS_DEBUG,
+				   xhci_extcap_dbc,
+				   ARRAY_SIZE(xhci_extcap_dbc),
+				   "reg-ext-dbc");
+
+	xhci_debugfs_create_ring_dir(xhci, xhci->cmd_ring,
+				     "command-ring",
+				     xhci->debugfs_root);
+
+	xhci_debugfs_create_ring_dir(xhci, xhci->event_ring,
+				     "event-ring",
+				     xhci->debugfs_root);
+
+	dir = debugfs_create_dir("devices", xhci->debugfs_root);
+	if (IS_ERR_OR_NULL(dir))
+		return;
+
+	xhci->debugfs_slots = dir;
+}
+
+void xhci_debugfs_exit(struct xhci_hcd *xhci)
+{
+	struct xhci_regset	*rgs, *tmp;
+
+	debugfs_remove_recursive(xhci->debugfs_root);
+	xhci->debugfs_root = NULL;
+	xhci->debugfs_slots = NULL;
+
+	list_for_each_entry_safe(rgs, tmp, &xhci->regset_list, list)
+		xhci_debugfs_free_regset(rgs);
+}
+
+void __init xhci_debugfs_create_root(void)
+{
+	xhci_debugfs_root = debugfs_create_dir("xhci", usb_debug_root);
+}
+
+void __exit xhci_debugfs_remove_root(void)
+{
+	debugfs_remove_recursive(xhci_debugfs_root);
+	xhci_debugfs_root = NULL;
+}
diff --git a/drivers/usb/host/xhci-debugfs.h b/drivers/usb/host/xhci-debugfs.h
new file mode 100644
index 0000000..3adc997
--- /dev/null
+++ b/drivers/usb/host/xhci-debugfs.h
@@ -0,0 +1,137 @@
+/*
+ * xhci-debugfs.h - xHCI debugfs interface
+ *
+ * Copyright (C) 2017 Intel Corporation
+ *
+ * Author: Lu Baolu <baolu.lu@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __LINUX_XHCI_DEBUGFS_H
+#define __LINUX_XHCI_DEBUGFS_H
+
+#include <linux/debugfs.h>
+
+#define DEBUGFS_NAMELEN 32
+
+#define REG_CAPLENGTH					0x00
+#define REG_HCSPARAMS1					0x04
+#define REG_HCSPARAMS2					0x08
+#define REG_HCSPARAMS3					0x0c
+#define REG_HCCPARAMS1					0x10
+#define REG_DOORBELLOFF					0x14
+#define REG_RUNTIMEOFF					0x18
+#define REG_HCCPARAMS2					0x1c
+
+#define	REG_USBCMD					0x00
+#define REG_USBSTS					0x04
+#define REG_PAGESIZE					0x08
+#define REG_DNCTRL					0x14
+#define REG_CRCR					0x18
+#define REG_DCBAAP_LOW					0x30
+#define REG_DCBAAP_HIGH					0x34
+#define REG_CONFIG					0x38
+
+#define REG_MFINDEX					0x00
+#define REG_IR0_IMAN					0x20
+#define REG_IR0_IMOD					0x24
+#define REG_IR0_ERSTSZ					0x28
+#define REG_IR0_ERSTBA_LOW				0x30
+#define REG_IR0_ERSTBA_HIGH				0x34
+#define REG_IR0_ERDP_LOW				0x38
+#define REG_IR0_ERDP_HIGH				0x3c
+
+#define REG_EXTCAP_USBLEGSUP				0x00
+#define REG_EXTCAP_USBLEGCTLSTS				0x04
+
+#define REG_EXTCAP_REVISION				0x00
+#define REG_EXTCAP_NAME					0x04
+#define REG_EXTCAP_PORTINFO				0x08
+#define REG_EXTCAP_PORTTYPE				0x0c
+#define REG_EXTCAP_MANTISSA1				0x10
+#define REG_EXTCAP_MANTISSA2				0x14
+#define REG_EXTCAP_MANTISSA3				0x18
+#define REG_EXTCAP_MANTISSA4				0x1c
+#define REG_EXTCAP_MANTISSA5				0x20
+#define REG_EXTCAP_MANTISSA6				0x24
+
+#define REG_EXTCAP_DBC_CAPABILITY			0x00
+#define REG_EXTCAP_DBC_DOORBELL				0x04
+#define REG_EXTCAP_DBC_ERSTSIZE				0x08
+#define REG_EXTCAP_DBC_ERST_LOW				0x10
+#define REG_EXTCAP_DBC_ERST_HIGH			0x14
+#define REG_EXTCAP_DBC_ERDP_LOW				0x18
+#define REG_EXTCAP_DBC_ERDP_HIGH			0x1c
+#define REG_EXTCAP_DBC_CONTROL				0x20
+#define REG_EXTCAP_DBC_STATUS				0x24
+#define REG_EXTCAP_DBC_PORTSC				0x28
+#define REG_EXTCAP_DBC_CONT_LOW				0x30
+#define REG_EXTCAP_DBC_CONT_HIGH			0x34
+#define REG_EXTCAP_DBC_DEVINFO1				0x38
+#define REG_EXTCAP_DBC_DEVINFO2				0x3c
+
+#define dump_register(nm)				\
+{							\
+	.name	= __stringify(nm),			\
+	.offset	= REG_ ##nm,				\
+}
+
+struct xhci_regset {
+	char			name[DEBUGFS_NAMELEN];
+	struct debugfs_regset32	regset;
+	size_t			nregs;
+	struct dentry		*parent;
+	struct list_head	list;
+};
+
+struct xhci_file_map {
+	const char		*name;
+	int			(*show)(struct seq_file *s, void *unused);
+};
+
+struct xhci_ep_priv {
+	char			name[DEBUGFS_NAMELEN];
+	struct dentry		*root;
+};
+
+struct xhci_slot_priv {
+	char			name[DEBUGFS_NAMELEN];
+	struct dentry		*root;
+	struct xhci_ep_priv	*eps[31];
+	struct xhci_virt_device	*dev;
+};
+
+#ifdef CONFIG_DEBUG_FS
+void xhci_debugfs_init(struct xhci_hcd *xhci);
+void xhci_debugfs_exit(struct xhci_hcd *xhci);
+void __init xhci_debugfs_create_root(void);
+void __exit xhci_debugfs_remove_root(void);
+void xhci_debugfs_create_slot(struct xhci_hcd *xhci, int slot_id);
+void xhci_debugfs_remove_slot(struct xhci_hcd *xhci, int slot_id);
+void xhci_debugfs_create_endpoint(struct xhci_hcd *xhci,
+				  struct xhci_virt_device *virt_dev,
+				  int ep_index);
+void xhci_debugfs_remove_endpoint(struct xhci_hcd *xhci,
+				  struct xhci_virt_device *virt_dev,
+				  int ep_index);
+#else
+static inline void xhci_debugfs_init(struct xhci_hcd *xhci) { }
+static inline void xhci_debugfs_exit(struct xhci_hcd *xhci) { }
+static inline void __init xhci_debugfs_create_root(void) { }
+static inline void __exit xhci_debugfs_remove_root(void) { }
+static inline void xhci_debugfs_create_slot(struct xhci_hcd *x, int s) { }
+static inline void xhci_debugfs_remove_slot(struct xhci_hcd *x, int s) { }
+static inline void
+xhci_debugfs_create_endpoint(struct xhci_hcd *xhci,
+			     struct xhci_virt_device *virt_dev,
+			     int ep_index) { }
+static inline void
+xhci_debugfs_remove_endpoint(struct xhci_hcd *xhci,
+			     struct xhci_virt_device *virt_dev,
+			     int ep_index) { }
+#endif /* CONFIG_DEBUG_FS */
+
+#endif /* __LINUX_XHCI_DEBUGFS_H */
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 2a82c92..62fd109 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -28,6 +28,7 @@
 
 #include "xhci.h"
 #include "xhci-trace.h"
+#include "xhci-debugfs.h"
 
 /*
  * Allocates a generic ring segment from the ring pool, sets the dma address,
@@ -465,8 +466,6 @@ int xhci_ring_expansion(struct xhci_hcd *xhci, struct xhci_ring *ring,
 	return 0;
 }
 
-#define CTX_SIZE(_hcc) (HCC_64BYTE_CONTEXT(_hcc) ? 64 : 32)
-
 static struct xhci_container_ctx *xhci_alloc_container_ctx(struct xhci_hcd *xhci,
 						    int type, gfp_t flags)
 {
@@ -1496,7 +1495,6 @@ int xhci_endpoint_init(struct xhci_hcd *xhci,
 	ep_ctx->tx_info = cpu_to_le32(EP_MAX_ESIT_PAYLOAD_LO(max_esit_payload) |
 				      EP_AVG_TRB_LENGTH(avg_trb_len));
 
-	/* FIXME Debug endpoint context */
 	return 0;
 }
 
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index b2ff1ff..ea08c2a 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -32,6 +32,7 @@
 #include "xhci.h"
 #include "xhci-trace.h"
 #include "xhci-mtk.h"
+#include "xhci-debugfs.h"
 
 #define DRIVER_AUTHOR "Sarah Sharp"
 #define DRIVER_DESC "'eXtensible' Host Controller (xHC) Driver"
@@ -632,6 +633,9 @@ int xhci_run(struct usb_hcd *hcd)
 	}
 	xhci_dbg_trace(xhci, trace_xhci_dbg_init,
 			"Finished xhci_run for USB2 roothub");
+
+	xhci_debugfs_init(xhci);
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(xhci_run);
@@ -650,6 +654,8 @@ static void xhci_stop(struct usb_hcd *hcd)
 	u32 temp;
 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
 
+	xhci_debugfs_exit(xhci);
+
 	mutex_lock(&xhci->mutex);
 
 	/* Only halt host and free memory after both hcds are removed */
@@ -1600,6 +1606,8 @@ static int xhci_drop_endpoint(struct usb_hcd *hcd, struct usb_device *udev,
 	ctrl_ctx->add_flags &= cpu_to_le32(~drop_flag);
 	new_add_flags = le32_to_cpu(ctrl_ctx->add_flags);
 
+	xhci_debugfs_remove_endpoint(xhci, xhci->devs[udev->slot_id], ep_index);
+
 	xhci_endpoint_zero(xhci, xhci->devs[udev->slot_id], ep);
 
 	if (xhci->quirks & XHCI_MTK_HOST)
@@ -1722,6 +1730,8 @@ static int xhci_add_endpoint(struct usb_hcd *hcd, struct usb_device *udev,
 	/* Store the usb_device pointer for later use */
 	ep->hcpriv = udev;
 
+	xhci_debugfs_create_endpoint(xhci, virt_dev, ep_index);
+
 	xhci_dbg(xhci, "add ep 0x%x, slot id %d, new drop flags = %#x, new add flags = %#x\n",
 			(unsigned int) ep->desc.bEndpointAddress,
 			udev->slot_id,
@@ -3521,6 +3531,8 @@ static void xhci_free_dev(struct usb_hcd *hcd, struct usb_device *udev)
 	int i, ret;
 	struct xhci_command *command;
 
+	xhci_debugfs_remove_slot(xhci, udev->slot_id);
+
 	command = xhci_alloc_command(xhci, false, false, GFP_KERNEL);
 	if (!command)
 		return;
@@ -3693,6 +3705,8 @@ int xhci_alloc_dev(struct usb_hcd *hcd, struct usb_device *udev)
 
 	udev->slot_id = slot_id;
 
+	xhci_debugfs_create_slot(xhci, slot_id);
+
 #ifndef CONFIG_USB_DEFAULT_PERSIST
 	/*
 	 * If resetting upon resume, we can't put the controller into runtime
@@ -5003,6 +5017,8 @@ static int __init xhci_hcd_init(void)
 	if (usb_disabled())
 		return -ENODEV;
 
+	xhci_debugfs_create_root();
+
 	return 0;
 }
 
@@ -5010,7 +5026,10 @@ static int __init xhci_hcd_init(void)
  * If an init function is provided, an exit function must also be provided
  * to allow module unload.
  */
-static void __exit xhci_hcd_fini(void) { }
+static void __exit xhci_hcd_fini(void)
+{
+	xhci_debugfs_remove_root();
+}
 
 module_init(xhci_hcd_init);
 module_exit(xhci_hcd_fini);
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index e3e9352..e27a161 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -131,6 +131,8 @@ struct xhci_cap_regs {
 /* Extended Capabilities pointer from PCI base - section 5.3.6 */
 #define HCC_EXT_CAPS(p)		XHCI_HCC_EXT_CAPS(p)
 
+#define CTX_SIZE(_hcc)		(HCC_64BYTE_CONTEXT(_hcc) ? 64 : 32)
+
 /* db_off bitmask - bits 0:1 reserved */
 #define	DBOFF_MASK	(~0x3)
 
@@ -998,6 +1000,8 @@ struct xhci_virt_device {
 	struct xhci_tt_bw_info		*tt_info;
 	/* The current max exit latency for the enabled USB3 link states. */
 	u16				current_mel;
+	/* Used for the debugfs interfaces. */
+	void				*debugfs_private;
 };
 
 /*
@@ -1850,6 +1854,10 @@ struct xhci_hcd {
 /* Compliance Mode Timer Triggered every 2 seconds */
 #define COMP_MODE_RCVRY_MSECS 2000
 
+	struct dentry		*debugfs_root;
+	struct dentry		*debugfs_slots;
+	struct list_head	regset_list;
+
 	/* platform-specific data -- must come last */
 	unsigned long		priv[0] __aligned(sizeof(s64));
 };
@@ -2098,6 +2106,7 @@ struct xhci_ep_ctx *xhci_get_ep_ctx(struct xhci_hcd *xhci, struct xhci_container
 struct xhci_ring *xhci_triad_to_transfer_ring(struct xhci_hcd *xhci,
 		unsigned int slot_id, unsigned int ep_index,
 		unsigned int stream_id);
+
 static inline struct xhci_ring *xhci_urb_to_transfer_ring(struct xhci_hcd *xhci,
 								struct urb *urb)
 {
-- 
2.7.4

Re: [PATCH 1/1] usb: xhci: Add debugfs interface for xHCI driver

[Greg KH]

On Sat, Jul 29, 2017 at 04:18:03PM +0800, Lu Baolu wrote:
> +static void xhci_debugfs_create_files(struct xhci_hcd *xhci,
> +				      struct xhci_file_map *files,
> +				      size_t nentries, void *data,
> +				      struct dentry *parent,
> +				      const struct file_operations *fops)
> +{
> +	int			i;
> +	struct dentry		*file;
> +
> +	for (i = 0; i < nentries; i++) {
> +		file = debugfs_create_file(files[i].name, 0444,
> +					   parent, data, fops);
> +		if (IS_ERR_OR_NULL(file))
> +			break;

There's no need to ever check the return value of a debugfs_ function,
there's nothing you can do here, just keep calling it :)

And you will not get an error, you will only get NULL if there is an
error, as the only error you would get is if debugfs was not enabled.

> +static struct dentry *xhci_debugfs_create_ring_dir(struct xhci_hcd *xhci,
> +						   struct xhci_ring *ring,
> +						   const char *name,
> +						   struct dentry *parent)
> +{
> +	struct dentry		*dir;
> +
> +	dir = debugfs_create_dir(name, parent);
> +	if (IS_ERR_OR_NULL(dir))
> +		return NULL;

Same here.  Just keep going, you don't care about the return value, but
you can use it safely no matter what.


Same for other places in this patch as well.

thanks,

greg k-h

Re: [PATCH 1/1] usb: xhci: Add debugfs interface for xHCI driver

[Lu Baolu]

Hi Greg,


On 07/29/2017 09:34 PM, Greg KH wrote:
> On Sat, Jul 29, 2017 at 04:18:03PM +0800, Lu Baolu wrote:
>> +static void xhci_debugfs_create_files(struct xhci_hcd *xhci,
>> +				      struct xhci_file_map *files,
>> +				      size_t nentries, void *data,
>> +				      struct dentry *parent,
>> +				      const struct file_operations *fops)
>> +{
>> +	int			i;
>> +	struct dentry		*file;
>> +
>> +	for (i = 0; i < nentries; i++) {
>> +		file = debugfs_create_file(files[i].name, 0444,
>> +					   parent, data, fops);
>> +		if (IS_ERR_OR_NULL(file))
>> +			break;
> There's no need to ever check the return value of a debugfs_ function,
> there's nothing you can do here, just keep calling it :)
>
> And you will not get an error, you will only get NULL if there is an
> error, as the only error you would get is if debugfs was not enabled.
>
>> +static struct dentry *xhci_debugfs_create_ring_dir(struct xhci_hcd *xhci,
>> +						   struct xhci_ring *ring,
>> +						   const char *name,
>> +						   struct dentry *parent)
>> +{
>> +	struct dentry		*dir;
>> +
>> +	dir = debugfs_create_dir(name, parent);
>> +	if (IS_ERR_OR_NULL(dir))
>> +		return NULL;
> Same here.  Just keep going, you don't care about the return value, but
> you can use it safely no matter what.
>
>
> Same for other places in this patch as well.

Thanks for review. I will correct them in a v2 patch.

Best regards,
Lu Baolu