3 files changed, 219 insertions, 41 deletions

diff --git a/drivers/usb/host/ehci-dbg.c b/drivers/usb/host/ehci-dbg.c
index 754a146cf828..39673f8194d9 100644
--- a/drivers/usb/host/ehci-dbg.c
+++ b/drivers/usb/host/ehci-dbg.c
@@ -323,7 +323,43 @@ static inline void remove_debug_files (struct ehci_hcd *bus) { }
 
 #else
 
-/* troubleshooting help: expose state in sysfs */
+/* troubleshooting help: expose state in debugfs */
+
+static int debug_async_open(struct inode *, struct file *);
+static int debug_periodic_open(struct inode *, struct file *);
+static int debug_registers_open(struct inode *, struct file *);
+static int debug_async_open(struct inode *, struct file *);
+static ssize_t debug_output(struct file*, char __user*, size_t, loff_t*);
+static int debug_close(struct inode *, struct file *);
+
+static const struct file_operations debug_async_fops = {
+        .owner          = THIS_MODULE,
+        .open           = debug_async_open,
+        .read           = debug_output,
+        .release        = debug_close,
+};
+static const struct file_operations debug_periodic_fops = {
+        .owner          = THIS_MODULE,
+        .open           = debug_periodic_open,
+        .read           = debug_output,
+        .release        = debug_close,
+};
+static const struct file_operations debug_registers_fops = {
+        .owner          = THIS_MODULE,
+        .open           = debug_registers_open,
+        .read           = debug_output,
+        .release        = debug_close,
+};
+
+static struct dentry *ehci_debug_root;
+
+struct debug_buffer {
+        ssize_t (*fill_func)(struct debug_buffer *);    /* fill method */
+        struct usb_bus *bus;
+        struct mutex mutex;     /* protect filling of buffer */
+        size_t count;           /* number of characters filled into buffer */
+        char *page;
+};
 
 #define speed_char(info1) ({ char tmp; \
                 switch (info1 & (3 << 12)) { \
@@ -441,10 +477,8 @@ done:
         *nextp = next;
 }
 
-static ssize_t
-show_async(struct device *dev, struct device_attribute *attr, char *buf)
+static ssize_t fill_async_buffer(struct debug_buffer *buf)
 {
-        struct usb_bus          *bus;
         struct usb_hcd          *hcd;
         struct ehci_hcd         *ehci;
         unsigned long           flags;
@@ -452,14 +486,13 @@ show_async(struct device *dev, struct device_attribute *attr, char *buf)
         char                    *next;
         struct ehci_qh          *qh;
 
-        *buf = 0;
-
-        bus = dev_get_drvdata(dev);
-        hcd = bus_to_hcd(bus);
+        hcd = bus_to_hcd(buf->bus);
         ehci = hcd_to_ehci (hcd);
-        next = buf;
+        next = buf->page;
         size = PAGE_SIZE;
 
+        *next = 0;
+
         /* dumps a snapshot of the async schedule.
          * usually empty except for long-term bulk reads, or head.
          * one QH per line, and TDs we know about
@@ -477,16 +510,12 @@ show_async(struct device *dev, struct device_attribute *attr, char *buf)
         }
         spin_unlock_irqrestore (&ehci->lock, flags);
 
-        return strlen (buf);
+        return strlen(buf->page);
 }
-static DEVICE_ATTR(async, S_IRUGO, show_async, NULL);
 
 #define DBG_SCHED_LIMIT 64
-
-static ssize_t
-show_periodic(struct device *dev, struct device_attribute *attr, char *buf)
+static ssize_t fill_periodic_buffer(struct debug_buffer *buf)
 {
-        struct usb_bus          *bus;
         struct usb_hcd          *hcd;
         struct ehci_hcd         *ehci;
         unsigned long           flags;
@@ -500,10 +529,9 @@ show_periodic(struct device *dev, struct device_attribute *attr, char *buf)
                 return 0;
         seen_count = 0;
 
-        bus = dev_get_drvdata(dev);
-        hcd = bus_to_hcd(bus);
+        hcd = bus_to_hcd(buf->bus);
         ehci = hcd_to_ehci (hcd);
-        next = buf;
+        next = buf->page;
         size = PAGE_SIZE;
 
         temp = scnprintf (next, size, "size = %d\n", ehci->periodic_size);
@@ -623,14 +651,10 @@ show_periodic(struct device *dev, struct device_attribute *attr, char *buf)
 
         return PAGE_SIZE - size;
 }
-static DEVICE_ATTR(periodic, S_IRUGO, show_periodic, NULL);
-
 #undef DBG_SCHED_LIMIT
 
-static ssize_t
-show_registers(struct device *dev, struct device_attribute *attr, char *buf)
+static ssize_t fill_registers_buffer(struct debug_buffer *buf)
 {
-        struct usb_bus          *bus;
         struct usb_hcd          *hcd;
         struct ehci_hcd         *ehci;
         unsigned long           flags;
@@ -639,15 +663,14 @@ show_registers(struct device *dev, struct device_attribute *attr, char *buf)
         static char             fmt [] = "%*s\n";
         static char             label [] = "";
 
-        bus = dev_get_drvdata(dev);
-        hcd = bus_to_hcd(bus);
+        hcd = bus_to_hcd(buf->bus);
         ehci = hcd_to_ehci (hcd);
-        next = buf;
+        next = buf->page;
         size = PAGE_SIZE;
 
         spin_lock_irqsave (&ehci->lock, flags);
 
-        if (bus->controller->power.power_state.event) {
+        if (buf->bus->controller->power.power_state.event) {
                 size = scnprintf (next, size,
                         "bus %s, device %s (driver " DRIVER_VERSION ")\n"
                         "%s\n"
@@ -789,26 +812,150 @@ done:
 
         return PAGE_SIZE - size;
 }
-static DEVICE_ATTR(registers, S_IRUGO, show_registers, NULL);
 
-static inline void create_debug_files (struct ehci_hcd *ehci)
+static struct debug_buffer *alloc_buffer(struct usb_bus *bus,
+                                ssize_t (*fill_func)(struct debug_buffer *))
 {
-        struct device *dev = ehci_to_hcd(ehci)->self.dev;
-        int retval;
+        struct debug_buffer *buf;
+
+        buf = kzalloc(sizeof(struct debug_buffer), GFP_KERNEL);
 
-        retval = device_create_file(dev, &dev_attr_async);
-        retval = device_create_file(dev, &dev_attr_periodic);
-        retval = device_create_file(dev, &dev_attr_registers);
+        if (buf) {
+                buf->bus = bus;
+                buf->fill_func = fill_func;
+                mutex_init(&buf->mutex);
+        }
+
+        return buf;
 }
 
-static inline void remove_debug_files (struct ehci_hcd *ehci)
+static int fill_buffer(struct debug_buffer *buf)
 {
-        struct device *dev = ehci_to_hcd(ehci)->self.dev;
+        int ret = 0;
+
+        if (!buf->page)
+                buf->page = (char *)get_zeroed_page(GFP_KERNEL);
+
+        if (!buf->page) {
+                ret = -ENOMEM;
+                goto out;
+        }
+
+        ret = buf->fill_func(buf);
 
-        device_remove_file(dev, &dev_attr_async);
-        device_remove_file(dev, &dev_attr_periodic);
-        device_remove_file(dev, &dev_attr_registers);
+        if (ret >= 0) {
+                buf->count = ret;
+                ret = 0;
+        }
+
+out:
+        return ret;
 }
 
-#endif /* STUB_DEBUG_FILES */
+static ssize_t debug_output(struct file *file, char __user *user_buf,
+                            size_t len, loff_t *offset)
+{
+        struct debug_buffer *buf = file->private_data;
+        int ret = 0;
+
+        mutex_lock(&buf->mutex);
+        if (buf->count == 0) {
+                ret = fill_buffer(buf);
+                if (ret != 0) {
+                        mutex_unlock(&buf->mutex);
+                        goto out;
+                }
+        }
+        mutex_unlock(&buf->mutex);
+
+        ret = simple_read_from_buffer(user_buf, len, offset,
+                                      buf->page, buf->count);
+
+out:
+        return ret;
+
+}
+
+static int debug_close(struct inode *inode, struct file *file)
+{
+        struct debug_buffer *buf = file->private_data;
 
+        if (buf) {
+                if (buf->page)
+                        free_page((unsigned long)buf->page);
+                kfree(buf);
+        }
+
+        return 0;
+}
+static int debug_async_open(struct inode *inode, struct file *file)
+{
+        file->private_data = alloc_buffer(inode->i_private, fill_async_buffer);
+
+        return file->private_data ? 0 : -ENOMEM;
+}
+
+static int debug_periodic_open(struct inode *inode, struct file *file)
+{
+        file->private_data = alloc_buffer(inode->i_private,
+                                          fill_periodic_buffer);
+
+        return file->private_data ? 0 : -ENOMEM;
+}
+
+static int debug_registers_open(struct inode *inode, struct file *file)
+{
+        file->private_data = alloc_buffer(inode->i_private,
+                                          fill_registers_buffer);
+
+        return file->private_data ? 0 : -ENOMEM;
+}
+
+static inline void create_debug_files (struct ehci_hcd *ehci)
+{
+        struct usb_bus *bus = &ehci_to_hcd(ehci)->self;
+
+        ehci->debug_dir = debugfs_create_dir(bus->bus_name, ehci_debug_root);
+        if (!ehci->debug_dir)
+                goto dir_error;
+
+        ehci->debug_async = debugfs_create_file("async", S_IRUGO,
+                                                ehci->debug_dir, bus,
+                                                &debug_async_fops);
+        if (!ehci->debug_async)
+                goto async_error;
+
+        ehci->debug_periodic = debugfs_create_file("periodic", S_IRUGO,
+                                                   ehci->debug_dir, bus,
+                                                   &debug_periodic_fops);
+        if (!ehci->debug_periodic)
+                goto periodic_error;
+
+        ehci->debug_registers = debugfs_create_file("registers", S_IRUGO,
+                                                    ehci->debug_dir, bus,
+                                                    &debug_registers_fops);
+        if (!ehci->debug_registers)
+                goto registers_error;
+        return;
+
+registers_error:
+        debugfs_remove(ehci->debug_periodic);
+periodic_error:
+        debugfs_remove(ehci->debug_async);
+async_error:
+        debugfs_remove(ehci->debug_dir);
+dir_error:
+        ehci->debug_periodic = NULL;
+        ehci->debug_async = NULL;
+        ehci->debug_dir = NULL;
+}
+
+static inline void remove_debug_files (struct ehci_hcd *ehci)
+{
+        debugfs_remove(ehci->debug_registers);
+        debugfs_remove(ehci->debug_periodic);
+        debugfs_remove(ehci->debug_async);
+        debugfs_remove(ehci->debug_dir);
+}
+
+#endif /* STUB_DEBUG_FILES */
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 5f2d74ed5ad7..264182654f4c 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -33,6 +33,7 @@
 #include <linux/usb.h>
 #include <linux/moduleparam.h>
 #include <linux/dma-mapping.h>
+#include <linux/debugfs.h>
 
 #include "../core/hcd.h"
 
@@ -978,15 +979,30 @@ static int __init ehci_hcd_init(void)
                  sizeof(struct ehci_qh), sizeof(struct ehci_qtd),
                  sizeof(struct ehci_itd), sizeof(struct ehci_sitd));
 
+#ifdef DEBUG
+        ehci_debug_root = debugfs_create_dir("ehci", NULL);
+        if (!ehci_debug_root)
+                return -ENOENT;
+#endif
+
 #ifdef PLATFORM_DRIVER
         retval = platform_driver_register(&PLATFORM_DRIVER);
-        if (retval < 0)
+        if (retval < 0) {
+#ifdef DEBUG
+                debugfs_remove(ehci_debug_root);
+                ehci_debug_root = NULL;
+#endif
                 return retval;
+        }
 #endif
 
 #ifdef PCI_DRIVER
         retval = pci_register_driver(&PCI_DRIVER);
         if (retval < 0) {
+#ifdef DEBUG
+                debugfs_remove(ehci_debug_root);
+                ehci_debug_root = NULL;
+#endif
 #ifdef PLATFORM_DRIVER
                 platform_driver_unregister(&PLATFORM_DRIVER);
 #endif
@@ -997,6 +1013,10 @@ static int __init ehci_hcd_init(void)
 #ifdef PS3_SYSTEM_BUS_DRIVER
         retval = ps3_ehci_driver_register(&PS3_SYSTEM_BUS_DRIVER);
         if (retval < 0) {
+#ifdef DEBUG
+                debugfs_remove(ehci_debug_root);
+                ehci_debug_root = NULL;
+#endif
 #ifdef PLATFORM_DRIVER
                 platform_driver_unregister(&PLATFORM_DRIVER);
 #endif
@@ -1022,6 +1042,9 @@ static void __exit ehci_hcd_cleanup(void)
 #ifdef PS3_SYSTEM_BUS_DRIVER
         ps3_ehci_driver_unregister(&PS3_SYSTEM_BUS_DRIVER);
 #endif
+#ifdef DEBUG
+        debugfs_remove(ehci_debug_root);
+#endif
 }
 module_exit(ehci_hcd_cleanup);
 
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index 951d69fec513..10e71417c352 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -127,6 +127,14 @@ struct ehci_hcd {			/* one per controller */
 #else
 #       define COUNT(x) do {} while (0)
 #endif
+
+        /* debug files */
+#ifdef DEBUG
+        struct dentry           *debug_dir;
+        struct dentry           *debug_async;
+        struct dentry           *debug_periodic;
+        struct dentry           *debug_registers;
+#endif
 };
 
 /* convert between an HCD pointer and the corresponding EHCI_HCD */