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android_kernel_xiaomi_sm8350/drivers/usb/host/ehci-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

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/*
* Copyright (C) 2001-2004 by David Brownell
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/* this file is part of ehci-hcd.c */
/*-------------------------------------------------------------------------*/
/*
* EHCI Root Hub ... the nonsharable stuff
*
* Registers don't need cpu_to_le32, that happens transparently
*/
/*-------------------------------------------------------------------------*/
#ifdef CONFIG_PM
static int ehci_bus_suspend (struct usb_hcd *hcd)
{
struct ehci_hcd *ehci = hcd_to_ehci (hcd);
int port;
if (time_before (jiffies, ehci->next_statechange))
msleep(5);
port = HCS_N_PORTS (ehci->hcs_params);
spin_lock_irq (&ehci->lock);
/* stop schedules, clean any completed work */
if (HC_IS_RUNNING(hcd->state)) {
ehci_quiesce (ehci);
hcd->state = HC_STATE_QUIESCING;
}
ehci->command = readl (&ehci->regs->command);
if (ehci->reclaim)
end_unlink_async (ehci);
ehci_work(ehci);
/* suspend any active/unsuspended ports, maybe allow wakeup */
while (port--) {
u32 __iomem *reg = &ehci->regs->port_status [port];
u32 t1 = readl (reg) & ~PORT_RWC_BITS;
u32 t2 = t1;
if ((t1 & PORT_PE) && !(t1 & PORT_OWNER))
t2 |= PORT_SUSPEND;
if (device_may_wakeup(&hcd->self.root_hub->dev))
t2 |= PORT_WKOC_E|PORT_WKDISC_E|PORT_WKCONN_E;
else
t2 &= ~(PORT_WKOC_E|PORT_WKDISC_E|PORT_WKCONN_E);
if (t1 != t2) {
ehci_vdbg (ehci, "port %d, %08x -> %08x\n",
port + 1, t1, t2);
writel (t2, reg);
}
}
/* turn off now-idle HC */
del_timer_sync (&ehci->watchdog);
ehci_halt (ehci);
hcd->state = HC_STATE_SUSPENDED;
ehci->next_statechange = jiffies + msecs_to_jiffies(10);
spin_unlock_irq (&ehci->lock);
return 0;
}
/* caller has locked the root hub, and should reset/reinit on error */
static int ehci_bus_resume (struct usb_hcd *hcd)
{
struct ehci_hcd *ehci = hcd_to_ehci (hcd);
u32 temp;
int i;
int intr_enable;
if (time_before (jiffies, ehci->next_statechange))
msleep(5);
spin_lock_irq (&ehci->lock);
/* Ideally and we've got a real resume here, and no port's power
* was lost. (For PCI, that means Vaux was maintained.) But we
* could instead be restoring a swsusp snapshot -- so that BIOS was
* the last user of the controller, not reset/pm hardware keeping
* state we gave to it.
*/
/* re-init operational registers in case we lost power */
if (readl (&ehci->regs->intr_enable) == 0) {
/* at least some APM implementations will try to deliver
* IRQs right away, so delay them until we're ready.
*/
intr_enable = 1;
writel (0, &ehci->regs->segment);
writel (ehci->periodic_dma, &ehci->regs->frame_list);
writel ((u32)ehci->async->qh_dma, &ehci->regs->async_next);
} else
intr_enable = 0;
ehci_dbg(ehci, "resume root hub%s\n",
intr_enable ? " after power loss" : "");
/* restore CMD_RUN, framelist size, and irq threshold */
writel (ehci->command, &ehci->regs->command);
/* take ports out of suspend */
i = HCS_N_PORTS (ehci->hcs_params);
while (i--) {
temp = readl (&ehci->regs->port_status [i]);
temp &= ~(PORT_RWC_BITS
| PORT_WKOC_E | PORT_WKDISC_E | PORT_WKCONN_E);
if (temp & PORT_SUSPEND) {
ehci->reset_done [i] = jiffies + msecs_to_jiffies (20);
temp |= PORT_RESUME;
}
writel (temp, &ehci->regs->port_status [i]);
}
i = HCS_N_PORTS (ehci->hcs_params);
mdelay (20);
while (i--) {
temp = readl (&ehci->regs->port_status [i]);
if ((temp & PORT_SUSPEND) == 0)
continue;
temp &= ~(PORT_RWC_BITS | PORT_RESUME);
writel (temp, &ehci->regs->port_status [i]);
ehci_vdbg (ehci, "resumed port %d\n", i + 1);
}
(void) readl (&ehci->regs->command);
/* maybe re-activate the schedule(s) */
temp = 0;
if (ehci->async->qh_next.qh)
temp |= CMD_ASE;
if (ehci->periodic_sched)
temp |= CMD_PSE;
if (temp) {
ehci->command |= temp;
writel (ehci->command, &ehci->regs->command);
}
ehci->next_statechange = jiffies + msecs_to_jiffies(5);
hcd->state = HC_STATE_RUNNING;
/* Now we can safely re-enable irqs */
if (intr_enable)
writel (INTR_MASK, &ehci->regs->intr_enable);
spin_unlock_irq (&ehci->lock);
return 0;
}
#else
#define ehci_bus_suspend NULL
#define ehci_bus_resume NULL
#endif /* CONFIG_PM */
/*-------------------------------------------------------------------------*/
static int check_reset_complete (
struct ehci_hcd *ehci,
int index,
int port_status
) {
if (!(port_status & PORT_CONNECT)) {
ehci->reset_done [index] = 0;
return port_status;
}
/* if reset finished and it's still not enabled -- handoff */
if (!(port_status & PORT_PE)) {
/* with integrated TT, there's nobody to hand it to! */
if (ehci_is_TDI(ehci)) {
ehci_dbg (ehci,
"Failed to enable port %d on root hub TT\n",
index+1);
return port_status;
}
ehci_dbg (ehci, "port %d full speed --> companion\n",
index + 1);
// what happens if HCS_N_CC(params) == 0 ?
port_status |= PORT_OWNER;
port_status &= ~PORT_RWC_BITS;
writel (port_status, &ehci->regs->port_status [index]);
} else
ehci_dbg (ehci, "port %d high speed\n", index + 1);
return port_status;
}
/*-------------------------------------------------------------------------*/
/* build "status change" packet (one or two bytes) from HC registers */
static int
ehci_hub_status_data (struct usb_hcd *hcd, char *buf)
{
struct ehci_hcd *ehci = hcd_to_ehci (hcd);
u32 temp, status = 0;
int ports, i, retval = 1;
unsigned long flags;
/* if !USB_SUSPEND, root hub timers won't get shut down ... */
if (!HC_IS_RUNNING(hcd->state))
return 0;
/* init status to no-changes */
buf [0] = 0;
ports = HCS_N_PORTS (ehci->hcs_params);
if (ports > 7) {
buf [1] = 0;
retval++;
}
/* no hub change reports (bit 0) for now (power, ...) */
/* port N changes (bit N)? */
spin_lock_irqsave (&ehci->lock, flags);
for (i = 0; i < ports; i++) {
temp = readl (&ehci->regs->port_status [i]);
if (temp & PORT_OWNER) {
/* don't report this in GetPortStatus */
if (temp & PORT_CSC) {
temp &= ~PORT_RWC_BITS;
temp |= PORT_CSC;
writel (temp, &ehci->regs->port_status [i]);
}
continue;
}
if (!(temp & PORT_CONNECT))
ehci->reset_done [i] = 0;
if ((temp & (PORT_CSC | PORT_PEC | PORT_OCC)) != 0
// PORT_STAT_C_SUSPEND?
|| ((temp & PORT_RESUME) != 0
&& time_after (jiffies,
ehci->reset_done [i]))) {
if (i < 7)
buf [0] |= 1 << (i + 1);
else
buf [1] |= 1 << (i - 7);
status = STS_PCD;
}
}
/* FIXME autosuspend idle root hubs */
spin_unlock_irqrestore (&ehci->lock, flags);
return status ? retval : 0;
}
/*-------------------------------------------------------------------------*/
static void
ehci_hub_descriptor (
struct ehci_hcd *ehci,
struct usb_hub_descriptor *desc
) {
int ports = HCS_N_PORTS (ehci->hcs_params);
u16 temp;
desc->bDescriptorType = 0x29;
desc->bPwrOn2PwrGood = 10; /* ehci 1.0, 2.3.9 says 20ms max */
desc->bHubContrCurrent = 0;
desc->bNbrPorts = ports;
temp = 1 + (ports / 8);
desc->bDescLength = 7 + 2 * temp;
/* two bitmaps: ports removable, and usb 1.0 legacy PortPwrCtrlMask */
memset (&desc->bitmap [0], 0, temp);
memset (&desc->bitmap [temp], 0xff, temp);
temp = 0x0008; /* per-port overcurrent reporting */
if (HCS_PPC (ehci->hcs_params))
temp |= 0x0001; /* per-port power control */
else
temp |= 0x0002; /* no power switching */
#if 0
// re-enable when we support USB_PORT_FEAT_INDICATOR below.
if (HCS_INDICATOR (ehci->hcs_params))
temp |= 0x0080; /* per-port indicators (LEDs) */
#endif
desc->wHubCharacteristics = (__force __u16)cpu_to_le16 (temp);
}
/*-------------------------------------------------------------------------*/
#define PORT_WAKE_BITS (PORT_WKOC_E|PORT_WKDISC_E|PORT_WKCONN_E)
static int ehci_hub_control (
struct usb_hcd *hcd,
u16 typeReq,
u16 wValue,
u16 wIndex,
char *buf,
u16 wLength
) {
struct ehci_hcd *ehci = hcd_to_ehci (hcd);
int ports = HCS_N_PORTS (ehci->hcs_params);
u32 temp, status;
unsigned long flags;
int retval = 0;
/*
* FIXME: support SetPortFeatures USB_PORT_FEAT_INDICATOR.
* HCS_INDICATOR may say we can change LEDs to off/amber/green.
* (track current state ourselves) ... blink for diagnostics,
* power, "this is the one", etc. EHCI spec supports this.
*/
spin_lock_irqsave (&ehci->lock, flags);
switch (typeReq) {
case ClearHubFeature:
switch (wValue) {
case C_HUB_LOCAL_POWER:
case C_HUB_OVER_CURRENT:
/* no hub-wide feature/status flags */
break;
default:
goto error;
}
break;
case ClearPortFeature:
if (!wIndex || wIndex > ports)
goto error;
wIndex--;
temp = readl (&ehci->regs->port_status [wIndex]);
if (temp & PORT_OWNER)
break;
switch (wValue) {
case USB_PORT_FEAT_ENABLE:
writel (temp & ~PORT_PE,
&ehci->regs->port_status [wIndex]);
break;
case USB_PORT_FEAT_C_ENABLE:
writel((temp & ~PORT_RWC_BITS) | PORT_PEC,
&ehci->regs->port_status [wIndex]);
break;
case USB_PORT_FEAT_SUSPEND:
if (temp & PORT_RESET)
goto error;
if (ehci->no_selective_suspend)
break;
if (temp & PORT_SUSPEND) {
if ((temp & PORT_PE) == 0)
goto error;
/* resume signaling for 20 msec */
temp &= ~(PORT_RWC_BITS | PORT_WAKE_BITS);
writel (temp | PORT_RESUME,
&ehci->regs->port_status [wIndex]);
ehci->reset_done [wIndex] = jiffies
+ msecs_to_jiffies (20);
}
break;
case USB_PORT_FEAT_C_SUSPEND:
/* we auto-clear this feature */
break;
case USB_PORT_FEAT_POWER:
if (HCS_PPC (ehci->hcs_params))
writel (temp & ~(PORT_RWC_BITS | PORT_POWER),
&ehci->regs->port_status [wIndex]);
break;
case USB_PORT_FEAT_C_CONNECTION:
writel((temp & ~PORT_RWC_BITS) | PORT_CSC,
&ehci->regs->port_status [wIndex]);
break;
case USB_PORT_FEAT_C_OVER_CURRENT:
writel((temp & ~PORT_RWC_BITS) | PORT_OCC,
&ehci->regs->port_status [wIndex]);
break;
case USB_PORT_FEAT_C_RESET:
/* GetPortStatus clears reset */
break;
default:
goto error;
}
readl (&ehci->regs->command); /* unblock posted write */
break;
case GetHubDescriptor:
ehci_hub_descriptor (ehci, (struct usb_hub_descriptor *)
buf);
break;
case GetHubStatus:
/* no hub-wide feature/status flags */
memset (buf, 0, 4);
//cpu_to_le32s ((u32 *) buf);
break;
case GetPortStatus:
if (!wIndex || wIndex > ports)
goto error;
wIndex--;
status = 0;
temp = readl (&ehci->regs->port_status [wIndex]);
// wPortChange bits
if (temp & PORT_CSC)
status |= 1 << USB_PORT_FEAT_C_CONNECTION;
if (temp & PORT_PEC)
status |= 1 << USB_PORT_FEAT_C_ENABLE;
if (temp & PORT_OCC)
status |= 1 << USB_PORT_FEAT_C_OVER_CURRENT;
/* whoever resumes must GetPortStatus to complete it!! */
if ((temp & PORT_RESUME)
&& time_after (jiffies,
ehci->reset_done [wIndex])) {
status |= 1 << USB_PORT_FEAT_C_SUSPEND;
ehci->reset_done [wIndex] = 0;
/* stop resume signaling */
temp = readl (&ehci->regs->port_status [wIndex]);
writel (temp & ~(PORT_RWC_BITS | PORT_RESUME),
&ehci->regs->port_status [wIndex]);
retval = handshake (
&ehci->regs->port_status [wIndex],
PORT_RESUME, 0, 2000 /* 2msec */);
if (retval != 0) {
ehci_err (ehci, "port %d resume error %d\n",
wIndex + 1, retval);
goto error;
}
temp &= ~(PORT_SUSPEND|PORT_RESUME|(3<<10));
}
/* whoever resets must GetPortStatus to complete it!! */
if ((temp & PORT_RESET)
&& time_after (jiffies,
ehci->reset_done [wIndex])) {
status |= 1 << USB_PORT_FEAT_C_RESET;
ehci->reset_done [wIndex] = 0;
/* force reset to complete */
writel (temp & ~(PORT_RWC_BITS | PORT_RESET),
&ehci->regs->port_status [wIndex]);
/* REVISIT: some hardware needs 550+ usec to clear
* this bit; seems too long to spin routinely...
*/
retval = handshake (
&ehci->regs->port_status [wIndex],
PORT_RESET, 0, 750);
if (retval != 0) {
ehci_err (ehci, "port %d reset error %d\n",
wIndex + 1, retval);
goto error;
}
/* see what we found out */
temp = check_reset_complete (ehci, wIndex,
readl (&ehci->regs->port_status [wIndex]));
}
// don't show wPortStatus if it's owned by a companion hc
if (!(temp & PORT_OWNER)) {
if (temp & PORT_CONNECT) {
status |= 1 << USB_PORT_FEAT_CONNECTION;
// status may be from integrated TT
status |= ehci_port_speed(ehci, temp);
}
if (temp & PORT_PE)
status |= 1 << USB_PORT_FEAT_ENABLE;
if (temp & (PORT_SUSPEND|PORT_RESUME))
status |= 1 << USB_PORT_FEAT_SUSPEND;
if (temp & PORT_OC)
status |= 1 << USB_PORT_FEAT_OVER_CURRENT;
if (temp & PORT_RESET)
status |= 1 << USB_PORT_FEAT_RESET;
if (temp & PORT_POWER)
status |= 1 << USB_PORT_FEAT_POWER;
}
#ifndef EHCI_VERBOSE_DEBUG
if (status & ~0xffff) /* only if wPortChange is interesting */
#endif
dbg_port (ehci, "GetStatus", wIndex + 1, temp);
// we "know" this alignment is good, caller used kmalloc()...
*((__le32 *) buf) = cpu_to_le32 (status);
break;
case SetHubFeature:
switch (wValue) {
case C_HUB_LOCAL_POWER:
case C_HUB_OVER_CURRENT:
/* no hub-wide feature/status flags */
break;
default:
goto error;
}
break;
case SetPortFeature:
if (!wIndex || wIndex > ports)
goto error;
wIndex--;
temp = readl (&ehci->regs->port_status [wIndex]);
if (temp & PORT_OWNER)
break;
temp &= ~PORT_RWC_BITS;
switch (wValue) {
case USB_PORT_FEAT_SUSPEND:
if (ehci->no_selective_suspend)
break;
if ((temp & PORT_PE) == 0
|| (temp & PORT_RESET) != 0)
goto error;
if (device_may_wakeup(&hcd->self.root_hub->dev))
temp |= PORT_WAKE_BITS;
writel (temp | PORT_SUSPEND,
&ehci->regs->port_status [wIndex]);
break;
case USB_PORT_FEAT_POWER:
if (HCS_PPC (ehci->hcs_params))
writel (temp | PORT_POWER,
&ehci->regs->port_status [wIndex]);
break;
case USB_PORT_FEAT_RESET:
if (temp & PORT_RESUME)
goto error;
/* line status bits may report this as low speed,
* which can be fine if this root hub has a
* transaction translator built in.
*/
if ((temp & (PORT_PE|PORT_CONNECT)) == PORT_CONNECT
&& !ehci_is_TDI(ehci)
&& PORT_USB11 (temp)) {
ehci_dbg (ehci,
"port %d low speed --> companion\n",
wIndex + 1);
temp |= PORT_OWNER;
} else {
ehci_vdbg (ehci, "port %d reset\n", wIndex + 1);
temp |= PORT_RESET;
temp &= ~PORT_PE;
/*
* caller must wait, then call GetPortStatus
* usb 2.0 spec says 50 ms resets on root
*/
ehci->reset_done [wIndex] = jiffies
+ msecs_to_jiffies (50);
}
writel (temp, &ehci->regs->port_status [wIndex]);
break;
default:
goto error;
}
readl (&ehci->regs->command); /* unblock posted writes */
break;
default:
error:
/* "stall" on error */
retval = -EPIPE;
}
spin_unlock_irqrestore (&ehci->lock, flags);
return retval;
}
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