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linux/drivers/usb/host/uhci-hub.c
David Howells 7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers 
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:10:12 +01:00

402 lines
10 KiB
C
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/*
* Universal Host Controller Interface driver for USB.
*
* Maintainer: Alan Stern <stern@rowland.harvard.edu>
*
* (C) Copyright 1999 Linus Torvalds
* (C) Copyright 1999-2002 Johannes Erdfelt, johannes@erdfelt.com
* (C) Copyright 1999 Randy Dunlap
* (C) Copyright 1999 Georg Acher, acher@in.tum.de
* (C) Copyright 1999 Deti Fliegl, deti@fliegl.de
* (C) Copyright 1999 Thomas Sailer, sailer@ife.ee.ethz.ch
* (C) Copyright 2004 Alan Stern, stern@rowland.harvard.edu
*/
static __u8 root_hub_hub_des[] =
{
0x09, /* __u8 bLength; */
0x29, /* __u8 bDescriptorType; Hub-descriptor */
0x02, /* __u8 bNbrPorts; */
0x0a, /* __u16 wHubCharacteristics; */
0x00, /* (per-port OC, no power switching) */
0x01, /* __u8 bPwrOn2pwrGood; 2ms */
0x00, /* __u8 bHubContrCurrent; 0 mA */
0x00, /* __u8 DeviceRemovable; *** 7 Ports max *** */
0xff /* __u8 PortPwrCtrlMask; *** 7 ports max *** */
};
#define UHCI_RH_MAXCHILD 7
/* must write as zeroes */
#define WZ_BITS (USBPORTSC_RES2 | USBPORTSC_RES3 | USBPORTSC_RES4)
/* status change bits: nonzero writes will clear */
#define RWC_BITS (USBPORTSC_OCC | USBPORTSC_PEC | USBPORTSC_CSC)
/* A port that either is connected or has a changed-bit set will prevent
* us from AUTO_STOPPING.
*/
static int any_ports_active(struct uhci_hcd *uhci)
{
int port;
for (port = 0; port < uhci->rh_numports; ++port) {
if ((inw(uhci->io_addr + USBPORTSC1 + port * 2) &
(USBPORTSC_CCS | RWC_BITS)) ||
test_bit(port, &uhci->port_c_suspend))
return 1;
}
return 0;
}
static inline int get_hub_status_data(struct uhci_hcd *uhci, char *buf)
{
int port;
*buf = 0;
for (port = 0; port < uhci->rh_numports; ++port) {
if ((inw(uhci->io_addr + USBPORTSC1 + port * 2) & RWC_BITS) ||
test_bit(port, &uhci->port_c_suspend))
*buf |= (1 << (port + 1));
}
return !!*buf;
}
#define OK(x) len = (x); break
#define CLR_RH_PORTSTAT(x) \
status = inw(port_addr); \
status &= ~(RWC_BITS|WZ_BITS); \
status &= ~(x); \
status |= RWC_BITS & (x); \
outw(status, port_addr)
#define SET_RH_PORTSTAT(x) \
status = inw(port_addr); \
status |= (x); \
status &= ~(RWC_BITS|WZ_BITS); \
outw(status, port_addr)
/* UHCI controllers don't automatically stop resume signalling after 20 msec,
* so we have to poll and check timeouts in order to take care of it.
*/
static void uhci_finish_suspend(struct uhci_hcd *uhci, int port,
unsigned long port_addr)
{
int status;
int i;
if (inw(port_addr) & (USBPORTSC_SUSP | USBPORTSC_RD)) {
CLR_RH_PORTSTAT(USBPORTSC_SUSP | USBPORTSC_RD);
if (test_bit(port, &uhci->resuming_ports))
set_bit(port, &uhci->port_c_suspend);
/* The controller won't actually turn off the RD bit until
* it has had a chance to send a low-speed EOP sequence,
* which is supposed to take 3 bit times (= 2 microseconds).
* Experiments show that some controllers take longer, so
* we'll poll for completion. */
for (i = 0; i < 10; ++i) {
if (!(inw(port_addr) & USBPORTSC_RD))
break;
udelay(1);
}
}
clear_bit(port, &uhci->resuming_ports);
}
/* Wait for the UHCI controller in HP's iLO2 server management chip.
* It can take up to 250 us to finish a reset and set the CSC bit.
*/
static void wait_for_HP(unsigned long port_addr)
{
int i;
for (i = 10; i < 250; i += 10) {
if (inw(port_addr) & USBPORTSC_CSC)
return;
udelay(10);
}
/* Log a warning? */
}
static void uhci_check_ports(struct uhci_hcd *uhci)
{
unsigned int port;
unsigned long port_addr;
int status;
for (port = 0; port < uhci->rh_numports; ++port) {
port_addr = uhci->io_addr + USBPORTSC1 + 2 * port;
status = inw(port_addr);
if (unlikely(status & USBPORTSC_PR)) {
if (time_after_eq(jiffies, uhci->ports_timeout)) {
CLR_RH_PORTSTAT(USBPORTSC_PR);
udelay(10);
/* HP's server management chip requires
* a longer delay. */
if (to_pci_dev(uhci_dev(uhci))->vendor ==
PCI_VENDOR_ID_HP)
wait_for_HP(port_addr);
/* If the port was enabled before, turning
* reset on caused a port enable change.
* Turning reset off causes a port connect
* status change. Clear these changes. */
CLR_RH_PORTSTAT(USBPORTSC_CSC | USBPORTSC_PEC);
SET_RH_PORTSTAT(USBPORTSC_PE);
}
}
if (unlikely(status & USBPORTSC_RD)) {
if (!test_bit(port, &uhci->resuming_ports)) {
/* Port received a wakeup request */
set_bit(port, &uhci->resuming_ports);
uhci->ports_timeout = jiffies +
msecs_to_jiffies(20);
/* Make sure we see the port again
* after the resuming period is over. */
mod_timer(&uhci_to_hcd(uhci)->rh_timer,
uhci->ports_timeout);
} else if (time_after_eq(jiffies,
uhci->ports_timeout)) {
uhci_finish_suspend(uhci, port, port_addr);
}
}
}
}
static int uhci_hub_status_data(struct usb_hcd *hcd, char *buf)
{
struct uhci_hcd *uhci = hcd_to_uhci(hcd);
unsigned long flags;
int status = 0;
spin_lock_irqsave(&uhci->lock, flags);
uhci_scan_schedule(uhci);
if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags) || uhci->dead)
goto done;
uhci_check_ports(uhci);
status = get_hub_status_data(uhci, buf);
switch (uhci->rh_state) {
case UHCI_RH_SUSPENDING:
case UHCI_RH_SUSPENDED:
/* if port change, ask to be resumed */
if (status)
usb_hcd_resume_root_hub(hcd);
break;
case UHCI_RH_AUTO_STOPPED:
/* if port change, auto start */
if (status)
wakeup_rh(uhci);
break;
case UHCI_RH_RUNNING:
/* are any devices attached? */
if (!any_ports_active(uhci)) {
uhci->rh_state = UHCI_RH_RUNNING_NODEVS;
uhci->auto_stop_time = jiffies + HZ;
}
break;
case UHCI_RH_RUNNING_NODEVS:
/* auto-stop if nothing connected for 1 second */
if (any_ports_active(uhci))
uhci->rh_state = UHCI_RH_RUNNING;
else if (time_after_eq(jiffies, uhci->auto_stop_time))
suspend_rh(uhci, UHCI_RH_AUTO_STOPPED);
break;
default:
break;
}
done:
spin_unlock_irqrestore(&uhci->lock, flags);
return status;
}
/* size of returned buffer is part of USB spec */
static int uhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
u16 wIndex, char *buf, u16 wLength)
{
struct uhci_hcd *uhci = hcd_to_uhci(hcd);
int status, lstatus, retval = 0, len = 0;
unsigned int port = wIndex - 1;
unsigned long port_addr = uhci->io_addr + USBPORTSC1 + 2 * port;
u16 wPortChange, wPortStatus;
unsigned long flags;
if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags) || uhci->dead)
return -ETIMEDOUT;
spin_lock_irqsave(&uhci->lock, flags);
switch (typeReq) {
case GetHubStatus:
*(__le32 *)buf = cpu_to_le32(0);
OK(4); /* hub power */
case GetPortStatus:
if (port >= uhci->rh_numports)
goto err;
uhci_check_ports(uhci);
status = inw(port_addr);
/* Intel controllers report the OverCurrent bit active on.
* VIA controllers report it active off, so we'll adjust the
* bit value. (It's not standardized in the UHCI spec.)
*/
if (to_pci_dev(hcd->self.controller)->vendor ==
PCI_VENDOR_ID_VIA)
status ^= USBPORTSC_OC;
/* UHCI doesn't support C_RESET (always false) */
wPortChange = lstatus = 0;
if (status & USBPORTSC_CSC)
wPortChange |= USB_PORT_STAT_C_CONNECTION;
if (status & USBPORTSC_PEC)
wPortChange |= USB_PORT_STAT_C_ENABLE;
if (status & USBPORTSC_OCC)
wPortChange |= USB_PORT_STAT_C_OVERCURRENT;
if (test_bit(port, &uhci->port_c_suspend)) {
wPortChange |= USB_PORT_STAT_C_SUSPEND;
lstatus |= 1;
}
if (test_bit(port, &uhci->resuming_ports))
lstatus |= 4;
/* UHCI has no power switching (always on) */
wPortStatus = USB_PORT_STAT_POWER;
if (status & USBPORTSC_CCS)
wPortStatus |= USB_PORT_STAT_CONNECTION;
if (status & USBPORTSC_PE) {
wPortStatus |= USB_PORT_STAT_ENABLE;
if (status & (USBPORTSC_SUSP | USBPORTSC_RD))
wPortStatus |= USB_PORT_STAT_SUSPEND;
}
if (status & USBPORTSC_OC)
wPortStatus |= USB_PORT_STAT_OVERCURRENT;
if (status & USBPORTSC_PR)
wPortStatus |= USB_PORT_STAT_RESET;
if (status & USBPORTSC_LSDA)
wPortStatus |= USB_PORT_STAT_LOW_SPEED;
if (wPortChange)
dev_dbg(uhci_dev(uhci), "port %d portsc %04x,%02x\n",
wIndex, status, lstatus);
*(__le16 *)buf = cpu_to_le16(wPortStatus);
*(__le16 *)(buf + 2) = cpu_to_le16(wPortChange);
OK(4);
case SetHubFeature: /* We don't implement these */
case ClearHubFeature:
switch (wValue) {
case C_HUB_OVER_CURRENT:
case C_HUB_LOCAL_POWER:
OK(0);
default:
goto err;
}
break;
case SetPortFeature:
if (port >= uhci->rh_numports)
goto err;
switch (wValue) {
case USB_PORT_FEAT_SUSPEND:
SET_RH_PORTSTAT(USBPORTSC_SUSP);
OK(0);
case USB_PORT_FEAT_RESET:
SET_RH_PORTSTAT(USBPORTSC_PR);
/* Reset terminates Resume signalling */
uhci_finish_suspend(uhci, port, port_addr);
/* USB v2.0 7.1.7.5 */
uhci->ports_timeout = jiffies + msecs_to_jiffies(50);
OK(0);
case USB_PORT_FEAT_POWER:
/* UHCI has no power switching */
OK(0);
default:
goto err;
}
break;
case ClearPortFeature:
if (port >= uhci->rh_numports)
goto err;
switch (wValue) {
case USB_PORT_FEAT_ENABLE:
CLR_RH_PORTSTAT(USBPORTSC_PE);
/* Disable terminates Resume signalling */
uhci_finish_suspend(uhci, port, port_addr);
OK(0);
case USB_PORT_FEAT_C_ENABLE:
CLR_RH_PORTSTAT(USBPORTSC_PEC);
OK(0);
case USB_PORT_FEAT_SUSPEND:
if (!(inw(port_addr) & USBPORTSC_SUSP)) {
/* Make certain the port isn't suspended */
uhci_finish_suspend(uhci, port, port_addr);
} else if (!test_and_set_bit(port,
&uhci->resuming_ports)) {
SET_RH_PORTSTAT(USBPORTSC_RD);
/* The controller won't allow RD to be set
* if the port is disabled. When this happens
* just skip the Resume signalling.
*/
if (!(inw(port_addr) & USBPORTSC_RD))
uhci_finish_suspend(uhci, port,
port_addr);
else
/* USB v2.0 7.1.7.7 */
uhci->ports_timeout = jiffies +
msecs_to_jiffies(20);
}
OK(0);
case USB_PORT_FEAT_C_SUSPEND:
clear_bit(port, &uhci->port_c_suspend);
OK(0);
case USB_PORT_FEAT_POWER:
/* UHCI has no power switching */
goto err;
case USB_PORT_FEAT_C_CONNECTION:
CLR_RH_PORTSTAT(USBPORTSC_CSC);
OK(0);
case USB_PORT_FEAT_C_OVER_CURRENT:
CLR_RH_PORTSTAT(USBPORTSC_OCC);
OK(0);
case USB_PORT_FEAT_C_RESET:
/* this driver won't report these */
OK(0);
default:
goto err;
}
break;
case GetHubDescriptor:
len = min_t(unsigned int, sizeof(root_hub_hub_des), wLength);
memcpy(buf, root_hub_hub_des, len);
if (len > 2)
buf[2] = uhci->rh_numports;
OK(len);
default:
err:
retval = -EPIPE;
}
spin_unlock_irqrestore(&uhci->lock, flags);
return retval;
}
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