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usb: Make core allocate resources per PCI-device.
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Introduce the notion of a PCI device that may be associated with more than
one USB host controller driver (struct usb_hcd).  This patch is the start
of the work to separate the xHCI host controller into two roothubs: a USB
3.0 roothub with SuperSpeed-only ports, and a USB 2.0 roothub with
HS/FS/LS ports.

One usb_hcd structure is designated to be the "primary HCD", and a pointer
is added to the usb_hcd structure to keep track of that.  A new function
call, usb_hcd_is_primary_hcd() is added to check whether the USB hcd is
marked as the primary HCD (or if it is not part of a roothub pair).  To
allow the USB core and xHCI driver to access either roothub in a pair, a
"shared_hcd" pointer is added to the usb_hcd structure.

Add a new function, usb_create_shared_hcd(), that does roothub allocation
for paired roothubs.  It will act just like usb_create_hcd() did if the
primary_hcd pointer argument is NULL.  If it is passed a non-NULL
primary_hcd pointer, it sets usb_hcd->shared_hcd and usb_hcd->primary_hcd
fields.  It will also skip the bandwidth_mutex allocation, and set the
secondary hcd's bandwidth_mutex pointer to the primary HCD's mutex.

IRQs are only allocated once for the primary roothub.

Introduce a new usb_hcd driver flag that indicates the host controller
driver wants to create two roothubs.  If the HCD_SHARED flag is set, then
the USB core PCI probe methods will allocate a second roothub, and make
sure that second roothub gets freed during rmmod and in initialization
error paths.

When usb_hc_died() is called with the primary HCD, make sure that any
roothubs that share that host controller are also marked as being dead.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
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Sarah Sharp committed Mar 14, 2011
1 parent 83de4b2 commit c563543
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Showing 2 changed files with 96 additions and 19 deletions.
108 changes: 89 additions & 19 deletions drivers/usb/core/hcd.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2143,7 +2143,9 @@ EXPORT_SYMBOL_GPL(usb_hcd_irq);
*
* This is called by bus glue to report a USB host controller that died
* while operations may still have been pending. It's called automatically
* by the PCI glue, so only glue for non-PCI busses should need to call it.
* by the PCI glue, so only glue for non-PCI busses should need to call it.
*
* Only call this function with the primary HCD.
*/
void usb_hc_died (struct usb_hcd *hcd)
{
Expand All @@ -2162,17 +2164,31 @@ void usb_hc_died (struct usb_hcd *hcd)
USB_STATE_NOTATTACHED);
usb_kick_khubd (hcd->self.root_hub);
}
if (usb_hcd_is_primary_hcd(hcd) && hcd->shared_hcd) {
hcd = hcd->shared_hcd;
if (hcd->rh_registered) {
clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);

/* make khubd clean up old urbs and devices */
usb_set_device_state(hcd->self.root_hub,
USB_STATE_NOTATTACHED);
usb_kick_khubd(hcd->self.root_hub);
}
}
spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
/* Make sure that the other roothub is also deallocated. */
}
EXPORT_SYMBOL_GPL (usb_hc_died);

/*-------------------------------------------------------------------------*/

/**
* usb_create_hcd - create and initialize an HCD structure
* usb_create_shared_hcd - create and initialize an HCD structure
* @driver: HC driver that will use this hcd
* @dev: device for this HC, stored in hcd->self.controller
* @bus_name: value to store in hcd->self.bus_name
* @primary_hcd: a pointer to the usb_hcd structure that is sharing the
* PCI device. Only allocate certain resources for the primary HCD
* Context: !in_interrupt()
*
* Allocate a struct usb_hcd, with extra space at the end for the
Expand All @@ -2181,8 +2197,9 @@ EXPORT_SYMBOL_GPL (usb_hc_died);
*
* If memory is unavailable, returns NULL.
*/
struct usb_hcd *usb_create_hcd (const struct hc_driver *driver,
struct device *dev, const char *bus_name)
struct usb_hcd *usb_create_shared_hcd(const struct hc_driver *driver,
struct device *dev, const char *bus_name,
struct usb_hcd *primary_hcd)
{
struct usb_hcd *hcd;

Expand All @@ -2191,16 +2208,24 @@ struct usb_hcd *usb_create_hcd (const struct hc_driver *driver,
dev_dbg (dev, "hcd alloc failed\n");
return NULL;
}
hcd->bandwidth_mutex = kmalloc(sizeof(*hcd->bandwidth_mutex),
GFP_KERNEL);
if (!hcd->bandwidth_mutex) {
kfree(hcd);
dev_dbg(dev, "hcd bandwidth mutex alloc failed\n");
return NULL;
if (primary_hcd == NULL) {
hcd->bandwidth_mutex = kmalloc(sizeof(*hcd->bandwidth_mutex),
GFP_KERNEL);
if (!hcd->bandwidth_mutex) {
kfree(hcd);
dev_dbg(dev, "hcd bandwidth mutex alloc failed\n");
return NULL;
}
mutex_init(hcd->bandwidth_mutex);
dev_set_drvdata(dev, hcd);
} else {
hcd->bandwidth_mutex = primary_hcd->bandwidth_mutex;
hcd->primary_hcd = primary_hcd;
primary_hcd->primary_hcd = primary_hcd;
hcd->shared_hcd = primary_hcd;
primary_hcd->shared_hcd = hcd;
}
mutex_init(hcd->bandwidth_mutex);

dev_set_drvdata(dev, hcd);
kref_init(&hcd->kref);

usb_bus_init(&hcd->self);
Expand All @@ -2221,13 +2246,46 @@ struct usb_hcd *usb_create_hcd (const struct hc_driver *driver,
"USB Host Controller";
return hcd;
}
EXPORT_SYMBOL_GPL(usb_create_shared_hcd);

/**
* usb_create_hcd - create and initialize an HCD structure
* @driver: HC driver that will use this hcd
* @dev: device for this HC, stored in hcd->self.controller
* @bus_name: value to store in hcd->self.bus_name
* Context: !in_interrupt()
*
* Allocate a struct usb_hcd, with extra space at the end for the
* HC driver's private data. Initialize the generic members of the
* hcd structure.
*
* If memory is unavailable, returns NULL.
*/
struct usb_hcd *usb_create_hcd(const struct hc_driver *driver,
struct device *dev, const char *bus_name)
{
return usb_create_shared_hcd(driver, dev, bus_name, NULL);
}
EXPORT_SYMBOL_GPL(usb_create_hcd);

/*
* Roothubs that share one PCI device must also share the bandwidth mutex.
* Don't deallocate the bandwidth_mutex until the last shared usb_hcd is
* deallocated.
*
* Make sure to only deallocate the bandwidth_mutex when the primary HCD is
* freed. When hcd_release() is called for the non-primary HCD, set the
* primary_hcd's shared_hcd pointer to null (since the non-primary HCD will be
* freed shortly).
*/
static void hcd_release (struct kref *kref)
{
struct usb_hcd *hcd = container_of (kref, struct usb_hcd, kref);

kfree(hcd->bandwidth_mutex);
if (usb_hcd_is_primary_hcd(hcd))
kfree(hcd->bandwidth_mutex);
else
hcd->shared_hcd->shared_hcd = NULL;
kfree(hcd);
}

Expand All @@ -2246,6 +2304,14 @@ void usb_put_hcd (struct usb_hcd *hcd)
}
EXPORT_SYMBOL_GPL(usb_put_hcd);

int usb_hcd_is_primary_hcd(struct usb_hcd *hcd)
{
if (!hcd->primary_hcd)
return 1;
return hcd == hcd->primary_hcd;
}
EXPORT_SYMBOL_GPL(usb_hcd_is_primary_hcd);

static int usb_hcd_request_irqs(struct usb_hcd *hcd,
unsigned int irqnum, unsigned long irqflags)
{
Expand Down Expand Up @@ -2367,9 +2433,11 @@ int usb_add_hcd(struct usb_hcd *hcd,
dev_dbg(hcd->self.controller, "supports USB remote wakeup\n");

/* enable irqs just before we start the controller */
retval = usb_hcd_request_irqs(hcd, irqnum, irqflags);
if (retval)
goto err_request_irq;
if (usb_hcd_is_primary_hcd(hcd)) {
retval = usb_hcd_request_irqs(hcd, irqnum, irqflags);
if (retval)
goto err_request_irq;
}

hcd->state = HC_STATE_RUNNING;
retval = hcd->driver->start(hcd);
Expand Down Expand Up @@ -2416,7 +2484,7 @@ int usb_add_hcd(struct usb_hcd *hcd,
clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
del_timer_sync(&hcd->rh_timer);
err_hcd_driver_start:
if (hcd->irq >= 0)
if (usb_hcd_is_primary_hcd(hcd) && hcd->irq >= 0)
free_irq(irqnum, hcd);
err_request_irq:
err_hcd_driver_setup:
Expand Down Expand Up @@ -2480,8 +2548,10 @@ void usb_remove_hcd(struct usb_hcd *hcd)
clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
del_timer_sync(&hcd->rh_timer);

if (hcd->irq >= 0)
free_irq(hcd->irq, hcd);
if (usb_hcd_is_primary_hcd(hcd)) {
if (hcd->irq >= 0)
free_irq(hcd->irq, hcd);
}

usb_put_dev(hcd->self.root_hub);
usb_deregister_bus(&hcd->self);
Expand Down
7 changes: 7 additions & 0 deletions include/linux/usb/hcd.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -147,6 +147,8 @@ struct usb_hcd {
* to the device, or resetting the bandwidth after a failed attempt.
*/
struct mutex *bandwidth_mutex;
struct usb_hcd *shared_hcd;
struct usb_hcd *primary_hcd;


#define HCD_BUFFER_POOLS 4
Expand Down Expand Up @@ -209,6 +211,7 @@ struct hc_driver {
int flags;
#define HCD_MEMORY 0x0001 /* HC regs use memory (else I/O) */
#define HCD_LOCAL_MEM 0x0002 /* HC needs local memory */
#define HCD_SHARED 0x0004 /* Two (or more) usb_hcds share HW */
#define HCD_USB11 0x0010 /* USB 1.1 */
#define HCD_USB2 0x0020 /* USB 2.0 */
#define HCD_USB3 0x0040 /* USB 3.0 */
Expand Down Expand Up @@ -370,8 +373,12 @@ extern int usb_hcd_get_frame_number(struct usb_device *udev);

extern struct usb_hcd *usb_create_hcd(const struct hc_driver *driver,
struct device *dev, const char *bus_name);
extern struct usb_hcd *usb_create_shared_hcd(const struct hc_driver *driver,
struct device *dev, const char *bus_name,
struct usb_hcd *shared_hcd);
extern struct usb_hcd *usb_get_hcd(struct usb_hcd *hcd);
extern void usb_put_hcd(struct usb_hcd *hcd);
extern int usb_hcd_is_primary_hcd(struct usb_hcd *hcd);
extern int usb_add_hcd(struct usb_hcd *hcd,
unsigned int irqnum, unsigned long irqflags);
extern void usb_remove_hcd(struct usb_hcd *hcd);
Expand Down

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