usb: xhci: Add debugfs interface for xHCI driver

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>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 137 insertions, 0 deletions

diff --git a/drivers/usb/host/xhci-debugfs.h b/drivers/usb/host/xhci-debugfs.h
new file mode 100644
index 000000000000..3adc9976f180
--- /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 */