[PATCH] usbcore: Improve endpoint sysfs file handling

This revised patch (as587b) improves the implementation of USB endpoint
sysfs files.  Instead of storing a whole bunch of attributes for every
single endpoint, each endpoint now gets its own kobject and they can
share a static list of attributes.  The number of extra fields added to
struct usb_host_endpoint has been reduced from 4 to 1.

The bEndpointAddress field is retained even though it is redundant (it
repeats the same information as the attributes' directory name).  The
code avoids calling kobject_register, to prevent generating unwanted
hotplug events.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
index 4bdbc9d..f18317f 100644 (file)
--- a/drivers/usb/core/sysfs.c
+++ b/drivers/usb/core/sysfs.c
@@ -23,43 +23,56 @@
 #include "usb.h"
 
 /* endpoint stuff */
-struct endpoint_attribute {
-       struct device_attribute dev_attr;
-       struct usb_endpoint_descriptor *endpoint;
+struct ep_object {
+       struct usb_endpoint_descriptor *desc;
        struct usb_device *udev;
+       struct kobject kobj;
 };
-#define to_endpoint_attr(_dev_attr) \
-       container_of(_dev_attr, struct endpoint_attribute, dev_attr)
-
-#define usb_ep_attr(field, format_string)                                      \
-static ssize_t show_ep_##field(struct device *dev, struct device_attribute *attr,      \
-                           char *buf)                                          \
-{                                                                              \
-       struct endpoint_attribute *endpoint_attr = to_endpoint_attr(attr);      \
-                                                                               \
-       return sprintf(buf, format_string, endpoint_attr->endpoint->field);     \
-}
+#define to_ep_object(_kobj) \
+       container_of(_kobj, struct ep_object, kobj)
+
+struct ep_attribute {
+       struct attribute attr;
+       ssize_t (*show)(struct usb_device *,
+                       struct usb_endpoint_descriptor *, char *);
+};
+#define to_ep_attribute(_attr) \
+       container_of(_attr, struct ep_attribute, attr)
+
+#define EP_ATTR(_name)                                         \
+struct ep_attribute ep_##_name = {                             \
+       .attr = {.name = #_name, .owner = THIS_MODULE,          \
+                       .mode = S_IRUGO},                       \
+       .show = show_ep_##_name}
+
+#define usb_ep_attr(field, format_string)                      \
+static ssize_t show_ep_##field(struct usb_device *udev,                \
+               struct usb_endpoint_descriptor *desc,           \
+               char *buf)                                      \
+{                                                              \
+       return sprintf(buf, format_string, desc->field);        \
+}                                                              \
+static EP_ATTR(field);
+
 usb_ep_attr(bLength, "%02x\n")
-usb_ep_attr(bDescriptorType, "%02x\n")
 usb_ep_attr(bEndpointAddress, "%02x\n")
 usb_ep_attr(bmAttributes, "%02x\n")
 usb_ep_attr(bInterval, "%02x\n")
 
-static ssize_t show_ep_wMaxPacketSize(struct device *dev,
-                                     struct device_attribute *attr, char *buf)
+static ssize_t show_ep_wMaxPacketSize(struct usb_device *udev,
+               struct usb_endpoint_descriptor *desc, char *buf)
 {
-       struct endpoint_attribute *endpoint_attr = to_endpoint_attr(attr);
-
        return sprintf(buf, "%04x\n",
-                     le16_to_cpu(endpoint_attr->endpoint->wMaxPacketSize) & 0x07ff);
+                       le16_to_cpu(desc->wMaxPacketSize) & 0x07ff);
 }
+static EP_ATTR(wMaxPacketSize);
 
-static ssize_t show_ep_type(struct device *dev, struct device_attribute *attr, char *buf)
+static ssize_t show_ep_type(struct usb_device *udev,
+               struct usb_endpoint_descriptor *desc, char *buf)
 {
-       struct endpoint_attribute *endpoint_attr = to_endpoint_attr(attr);
        char *type = "unknown";
 
-       switch (endpoint_attr->endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
+       switch (desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
        case USB_ENDPOINT_XFER_CONTROL:
                type = "Control";
                break;
@@ -75,35 +88,34 @@ static ssize_t show_ep_type(struct device *dev, struct device_attribute *attr, c
        }
        return sprintf(buf, "%s\n", type);
 }
+static EP_ATTR(type);
 
-static ssize_t show_ep_interval(struct device *dev, struct device_attribute *attr, char *buf)
+static ssize_t show_ep_interval(struct usb_device *udev,
+               struct usb_endpoint_descriptor *desc, char *buf)
 {
-       struct endpoint_attribute *endpoint_attr = to_endpoint_attr(attr);
-       struct usb_device *udev = endpoint_attr->udev;
-       struct usb_endpoint_descriptor *endpoint = endpoint_attr->endpoint;
        char unit;
        unsigned interval = 0;
        unsigned in;
 
-       in = (endpoint->bEndpointAddress & USB_DIR_IN);
+       in = (desc->bEndpointAddress & USB_DIR_IN);
 
-       switch (endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
+       switch (desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
        case USB_ENDPOINT_XFER_CONTROL:
                if (udev->speed == USB_SPEED_HIGH)      /* uframes per NAK */
-                       interval = endpoint->bInterval;
+                       interval = desc->bInterval;
                break;
        case USB_ENDPOINT_XFER_ISOC:
-               interval = 1 << (endpoint->bInterval - 1);
+               interval = 1 << (desc->bInterval - 1);
                break;
        case USB_ENDPOINT_XFER_BULK:
-               if (udev->speed == USB_SPEED_HIGH && !in)       /* uframes per NAK */
-                       interval = endpoint->bInterval;
+               if (udev->speed == USB_SPEED_HIGH && !in) /* uframes per NAK */
+                       interval = desc->bInterval;
                break;
        case USB_ENDPOINT_XFER_INT:
-               if (udev->speed == USB_SPEED_HIGH) {
-                       interval = 1 << (endpoint->bInterval - 1);
-               } else
-                       interval = endpoint->bInterval;
+               if (udev->speed == USB_SPEED_HIGH)
+                       interval = 1 << (desc->bInterval - 1);
+               else
+                       interval = desc->bInterval;
                break;
        }
        interval *= (udev->speed == USB_SPEED_HIGH) ? 125 : 1000;
@@ -116,78 +128,95 @@ static ssize_t show_ep_interval(struct device *dev, struct device_attribute *att
 
        return sprintf(buf, "%d%cs\n", interval, unit);
 }
+static EP_ATTR(interval);
 
-static ssize_t show_ep_direction(struct device *dev, struct device_attribute *attr, char *buf)
+static ssize_t show_ep_direction(struct usb_device *udev,
+               struct usb_endpoint_descriptor *desc, char *buf)
 {
-       struct endpoint_attribute *endpoint_attr = to_endpoint_attr(attr);
        char *direction;
 
-       if ((endpoint_attr->endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
-           USB_ENDPOINT_XFER_CONTROL)
+       if ((desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
+                       USB_ENDPOINT_XFER_CONTROL)
                direction = "both";
-       else if (endpoint_attr->endpoint->bEndpointAddress & USB_DIR_IN)
+       else if (desc->bEndpointAddress & USB_DIR_IN)
                direction = "in";
        else
                direction = "out";
        return sprintf(buf, "%s\n", direction);
 }
+static EP_ATTR(direction);
+
+static struct attribute *ep_attrs[] = {
+       &ep_bLength.attr,
+       &ep_bEndpointAddress.attr,
+       &ep_bmAttributes.attr,
+       &ep_bInterval.attr,
+       &ep_wMaxPacketSize.attr,
+       &ep_type.attr,
+       &ep_interval.attr,
+       &ep_direction.attr,
+       NULL,
+};
 
-static struct endpoint_attribute *create_ep_attr(struct usb_endpoint_descriptor *endpoint,
-                                                struct usb_device *udev, char *name,
-               ssize_t (*show)(struct device *dev, struct device_attribute *attr, char *buf))
+static void ep_object_release(struct kobject *kobj)
 {
-       struct endpoint_attribute *ep_attr;
-
-       ep_attr = kzalloc(sizeof(*ep_attr), GFP_KERNEL);
-       if (ep_attr) {
-               ep_attr->endpoint = endpoint;
-               ep_attr->udev = udev;
-               ep_attr->dev_attr.attr.name = name;
-               ep_attr->dev_attr.attr.mode = 0444;
-               ep_attr->dev_attr.attr.owner = THIS_MODULE;
-               ep_attr->dev_attr.show = show;
-       }
-       return ep_attr;
+       kfree(to_ep_object(kobj));
 }
 
-static void usb_create_ep_files(struct kobject *kobj, struct usb_host_endpoint *endpoint, struct usb_device *udev)
+static ssize_t ep_object_show(struct kobject *kobj, struct attribute *attr,
+               char *buf)
 {
-       struct usb_endpoint_descriptor *ep;
-
-       ep = &endpoint->desc;
-
-       endpoint->attrs = kzalloc(sizeof(struct attribute *) * 10, GFP_KERNEL);
-       endpoint->attrs[0] = &(create_ep_attr(ep, udev, "direction", show_ep_direction)->dev_attr.attr);
-       endpoint->attrs[1] = &(create_ep_attr(ep, udev, "type", show_ep_type)->dev_attr.attr);
-       endpoint->attrs[2] = &(create_ep_attr(ep, udev, "bLength", show_ep_bLength)->dev_attr.attr);
-       endpoint->attrs[3] = &(create_ep_attr(ep, udev, "bDescriptorType", show_ep_bDescriptorType)->dev_attr.attr);
-       endpoint->attrs[4] = &(create_ep_attr(ep, udev, "bEndpointAddress", show_ep_bEndpointAddress)->dev_attr.attr);
-       endpoint->attrs[5] = &(create_ep_attr(ep, udev, "bmAttributes", show_ep_bmAttributes)->dev_attr.attr);
-       endpoint->attrs[6] = &(create_ep_attr(ep, udev, "wMaxPacketSize", show_ep_wMaxPacketSize)->dev_attr.attr);
-       endpoint->attrs[7] = &(create_ep_attr(ep, udev, "bInterval", show_ep_bInterval)->dev_attr.attr);
-       endpoint->attrs[8] = &(create_ep_attr(ep, udev, "interval", show_ep_interval)->dev_attr.attr);
-       endpoint->attrs[9] = NULL;
-       endpoint->num_attrs = 9;
-
-       endpoint->attr_group = kzalloc(sizeof(*endpoint->attr_group), GFP_KERNEL);
-       endpoint->attr_name = kzalloc(10, GFP_KERNEL);
-       sprintf(endpoint->attr_name, "ep_%02x", endpoint->desc.bEndpointAddress);
-
-       endpoint->attr_group->attrs = endpoint->attrs;
-       endpoint->attr_group->name = endpoint->attr_name;
-       sysfs_create_group(kobj, endpoint->attr_group);
+       struct ep_object *ep_obj = to_ep_object(kobj);
+       struct ep_attribute *ep_attr = to_ep_attribute(attr);
+
+       return (ep_attr->show)(ep_obj->udev, ep_obj->desc, buf);
 }
 
-static void usb_remove_ep_files(struct kobject *kobj, struct usb_host_endpoint *endpoint)
+static struct sysfs_ops ep_object_sysfs_ops = {
+       .show =                 ep_object_show,
+};
+
+static struct kobj_type ep_object_ktype = {
+       .release =              ep_object_release,
+       .sysfs_ops =            &ep_object_sysfs_ops,
+       .default_attrs =        ep_attrs,
+};
+
+static void usb_create_ep_files(struct kobject *parent,
+               struct usb_host_endpoint *endpoint,
+               struct usb_device *udev)
 {
-       int i;
+       struct ep_object *ep_obj;
+       struct kobject *kobj;
+
+       ep_obj = kzalloc(sizeof(struct ep_object), GFP_KERNEL);
+       if (!ep_obj)
+               return;
 
-       sysfs_remove_group(kobj, endpoint->attr_group);
-       kfree(endpoint->attr_group);
-       kfree(endpoint->attr_name);
-       for (i = 0; i < endpoint->num_attrs; ++i)
-               kfree(endpoint->attrs[i]);
-       kfree(endpoint->attrs);
+       ep_obj->desc = &endpoint->desc;
+       ep_obj->udev = udev;
+
+       kobj = &ep_obj->kobj;
+       kobject_set_name(kobj, "ep_%02x", endpoint->desc.bEndpointAddress);
+       kobj->parent = parent;
+       kobj->ktype = &ep_object_ktype;
+
+       /* Don't use kobject_register, because it generates a hotplug event */
+       kobject_init(kobj);
+       if (kobject_add(kobj) == 0)
+               endpoint->kobj = kobj;
+       else
+               kobject_put(kobj);
+}
+
+static void usb_remove_ep_files(struct usb_host_endpoint *endpoint)
+{
+
+       if (endpoint->kobj) {
+               kobject_del(endpoint->kobj);
+               kobject_put(endpoint->kobj);
+               endpoint->kobj = NULL;
+       }
 }
 
 /* Active configuration fields */
@@ -411,7 +440,7 @@ void usb_remove_sysfs_dev_files (struct usb_device *udev)
 {
        struct device *dev = &udev->dev;
 
-       usb_remove_ep_files(&dev->kobj, &udev->ep0);
+       usb_remove_ep_files(&udev->ep0);
        sysfs_remove_group(&dev->kobj, &dev_attr_grp);
 
        if (udev->descriptor.iManufacturer)
@@ -496,7 +525,7 @@ static struct attribute_group intf_attr_grp = {
        .attrs = intf_attrs,
 };
 
-static void usb_create_intf_ep_files(struct usb_interface *intf)
+static inline void usb_create_intf_ep_files(struct usb_interface *intf)
 {
        struct usb_host_interface *iface_desc;
        int i;
@@ -504,17 +533,17 @@ static void usb_create_intf_ep_files(struct usb_interface *intf)
        iface_desc = intf->cur_altsetting;
        for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i)
                usb_create_ep_files(&intf->dev.kobj, &iface_desc->endpoint[i],
-                                   interface_to_usbdev(intf));
+                               interface_to_usbdev(intf));
 }
 
-static void usb_remove_intf_ep_files(struct usb_interface *intf)
+static inline void usb_remove_intf_ep_files(struct usb_interface *intf)
 {
        struct usb_host_interface *iface_desc;
        int i;
 
        iface_desc = intf->cur_altsetting;
        for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i)
-               usb_remove_ep_files(&intf->dev.kobj, &iface_desc->endpoint[i]);
+               usb_remove_ep_files(&iface_desc->endpoint[i]);
 }
 
 void usb_create_sysfs_intf_files (struct usb_interface *intf)

diff --git a/include/linux/usb.h b/include/linux/usb.h
index a2d923f..465ff45 100644 (file)
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -57,10 +57,7 @@ struct usb_host_endpoint {
        struct usb_endpoint_descriptor  desc;
        struct list_head                urb_list;
        void                            *hcpriv;
-       char                            *attr_name;
-       struct attribute_group          *attr_group;
-       struct attribute                **attrs;
-       int                             num_attrs;
+       struct kobject                  *kobj;  /* For sysfs info */
 
        unsigned char *extra;   /* Extra descriptors */
        int extralen;