usb: core: switch bus numbering to using idr
USB bus numbering is based on directly dealing with bitmaps and
defines a separate list of busses.
This can be simplified and unified by using existing idr functionality.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/core/devices.c b/drivers/usb/core/devices.c
index b35a6a5..6118a04 100644
--- a/drivers/usb/core/devices.c
+++ b/drivers/usb/core/devices.c
@@ -110,13 +110,6 @@
/* E: Ad=xx(s) Atr=xx(ssss) MxPS=dddd Ivl=D?s */
"E: Ad=%02x(%c) Atr=%02x(%-4s) MxPS=%4d Ivl=%d%cs\n";
-
-/*
- * Need access to the driver and USB bus lists.
- * extern struct list_head usb_bus_list;
- * However, these will come from functions that return ptrs to each of them.
- */
-
/*
* Wait for an connect/disconnect event to happen. We initialize
* the event counter with an odd number, and each event will increment
@@ -618,6 +611,7 @@
struct usb_bus *bus;
ssize_t ret, total_written = 0;
loff_t skip_bytes = *ppos;
+ int id;
if (*ppos < 0)
return -EINVAL;
@@ -628,7 +622,7 @@
mutex_lock(&usb_bus_list_lock);
/* print devices for all busses */
- list_for_each_entry(bus, &usb_bus_list, bus_list) {
+ idr_for_each_entry(&usb_bus_idr, bus, id) {
/* recurse through all children of the root hub */
if (!bus_to_hcd(bus)->rh_registered)
continue;
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 232c8c9..cf3eb22 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -90,12 +90,11 @@
EXPORT_SYMBOL_GPL(usb_hcds_loaded);
/* host controllers we manage */
-LIST_HEAD (usb_bus_list);
-EXPORT_SYMBOL_GPL (usb_bus_list);
+DEFINE_IDR (usb_bus_idr);
+EXPORT_SYMBOL_GPL (usb_bus_idr);
/* used when allocating bus numbers */
#define USB_MAXBUS 64
-static DECLARE_BITMAP(busmap, USB_MAXBUS);
/* used when updating list of hcds */
DEFINE_MUTEX(usb_bus_list_lock); /* exported only for usbfs */
@@ -996,8 +995,6 @@
bus->bandwidth_int_reqs = 0;
bus->bandwidth_isoc_reqs = 0;
mutex_init(&bus->usb_address0_mutex);
-
- INIT_LIST_HEAD (&bus->bus_list);
}
/*-------------------------------------------------------------------------*/
@@ -1018,16 +1015,12 @@
int busnum;
mutex_lock(&usb_bus_list_lock);
- busnum = find_next_zero_bit(busmap, USB_MAXBUS, 1);
- if (busnum >= USB_MAXBUS) {
- printk (KERN_ERR "%s: too many buses\n", usbcore_name);
+ busnum = idr_alloc(&usb_bus_idr, bus, 1, USB_MAXBUS, GFP_KERNEL);
+ if (busnum < 0) {
+ pr_err("%s: failed to get bus number\n", usbcore_name);
goto error_find_busnum;
}
- set_bit(busnum, busmap);
bus->busnum = busnum;
-
- /* Add it to the local list of buses */
- list_add (&bus->bus_list, &usb_bus_list);
mutex_unlock(&usb_bus_list_lock);
usb_notify_add_bus(bus);
@@ -1059,12 +1052,10 @@
* itself up
*/
mutex_lock(&usb_bus_list_lock);
- list_del (&bus->bus_list);
+ idr_remove(&usb_bus_idr, bus->busnum);
mutex_unlock(&usb_bus_list_lock);
usb_notify_remove_bus(bus);
-
- clear_bit(bus->busnum, busmap);
}
/**
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 16ade41..524c982 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -1115,6 +1115,7 @@
bus_unregister(&usb_bus_type);
usb_acpi_unregister();
usb_debugfs_cleanup();
+ idr_destroy(&usb_bus_idr);
}
subsys_initcall(usb_init);