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: NDavid Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)

This revamps handling of the hardware "async advance" IRQ, and its watchdog
timer.  Basically it dis-entangles that important timeout from the others,
simplifying the associated state and code to make it more robust.

This reportedly improves behavior of EHCI on some systems with VIA chips,
and AFAIK won't affect non-VIA hardware.  VIA systems need this code to
recover from silcon bugs whereby the "async advance" IRQ isn't issued.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

If some problem occurs during ehci startup, for instance, request_irq fails,
echi hcd driver tries it best to cleanup, but fails to unregister reboot
notifier, which in turn leads to crash on reboot/poweroff.

The following patch resolves this problem by not using reboot notifiers
anymore, but instead making ehci/ohci driver get its own shutdown method.  For
PCI, it is done through pci glue, for everything else through platform driver
glue.

One downside: sa1111 does not use platform driver stuff, and does not have its
own shutdown hook, so no 'shutdown' is called for it now.  I'm not sure if it
is really necessary on that platform, though.
Signed-off-by: NAleks Gorelov <dared1st@yahoo.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This teaches several USB host controller drivers to treat PRETHAW as a chip
reset since the controller, and all devices connected to it, are no longer in
states compatible with how the snapshotted suspend() left them.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

In some systems we may have both a platform EHCI controller and PCI EHCI
controller.  Previously we couldn't build the EHCI support as a module due
to conflicting module_init() calls in the code.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

From: Paul Serice <paul@serice.net>

The workaround in commit f7201c3d
broke.  The work around requires memory for DMA transfers for some
NVidia EHCI controllers to be below 2GB, but recent changes have
caused some DMA memory to be allocated before the DMA mask is set.
Signed-off-by: NPaul Serice <paul@serice.net>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

We could use the recently added PCI_CLASS_SERIAL_USB_UHCI,
PCI_CLASS_SERIAL_USB_OHCI and PCI_CLASS_SERIAL_USB_EHCI defines in
more places, for slightly shorter and clearer code.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This teaches the EHCI driver about a quirk seen in older NForce2 chips,
adding a workaround to ignore selective suspend requests.  Bus-wide
(so-called "global") suspend still works, as does USB wakeup of a
root hub that's globally suspended.

There's still a hole in this support though.  Strictly speaking, this
should _fail_ selective suspend requests, rather than ignoring them,
since doing it this way means that devices which should be able to issue
remote wakeup are not going to be able to do that.  For now, we'll just
live with that problem ... since usbcore expects to do selective suspend
on the way towards a full bus suspend, and usbcore needs to be able to
do full bus suspend.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This moves the previously widely-used ehci-pci.c BIOS handoff
code into the pci-quirks.c file, replacing the less widely used
"early handoff" version that seems to cause problems lately.

One notable change:  the "early handoff" version always enabled
an SMI IRQ ... and did so even if the pre-Linux code said it was
not using EHCI (and not expecting EHCI SMIs).  Looks like a goof
in a workaround for some unknown BIOS version.

This merged version only forcibly enables those IRQs when pre-Linux
code says it's using EHCI.  And now it always forces them off "just
in case".
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as515b) adds a routine to usbcore to simplify handling of
host controllers that lost power or were reset during suspend/resume.
The new core routine marks all the child devices of the root hub as
NOTATTACHED and tells khubd to disconnect the device structures as soon
as possible.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This teaches the EHCI driver to use the new driver model wakeup flags,
replacing the similar ones in the HCD glue.  It also adds a workaround
for the current glitch whereby PCI init doesn't init the wakeup flags
from the PCI PM capabilities.  (EHCI controllers don't worry about
legacy mode; the PCI PM capability would always do the job.)
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Rename the EHCI "reset" routine so it better matches what it does (setup);
and move the one-time data structure setup earlier, before doing anything
that implicitly relies on it having been completed already.

From: David Brownell <david-b@pacbell.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch closes the IRQ race and makes various other OHCI & EHCI code
path safer vs. suspend/resume.
I've been able to (finally !) successfully suspend and resume various
Mac models, with or without USB mouse plugged, or plugging while asleep,
or unplugging while asleep etc... all without a crash.

Alan, please verify the UHCI bit I did, I only verified that it builds.
It's very simple so I wouldn't expect any issue there. If you aren't
confident, then just drop the hunks that change uhci-hcd.c

I also made the patch a little bit more "safer" by making sure the store
to the interrupt register that disables interrupts is not posted before
I set the flag and drop the spinlock.

Without this patch, you cannot reliably sleep/wakeup any recent Mac, and
I suspect PCs have some more sneaky issues too (they don't frankly crash
with machine checks because x86 tend to silently swallow PCI errors but
that won't last afaik, at least PCI Express will blow up in those
situations, but the USB code may still misbehave).
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Moving the PCI-specific parts of the EHCI driver into their own file
created a few issues ... notably on resume paths which (like swsusp)
require re-initializing the controller.  This patch:

 - Splits the EHCI startup code into run-once HCD setup code and
   separate "init the hardware" reinit code.  (That reinit code is
   a superset of the "early usb handoff" code.)

 - Then it makes the PCI init code run both, and the resume code only
   run the reinit code.

 - It also removes needless pci wrappers around EHCI start/stop methods.

 - Removes a byteswap issue that would be seen on big-endian hardware.

The HCD glue still doesn't actually provide a good way to do all this
run-one init stuff in one place though.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This cleans up the recent updates to EHCI PCI support:

  - Gets rid of checks for "is this a PCI device", they're no
    longer needed since this is now all PCI-only code.

  - Reduce log spamming:  MWI is only interesting in the atypical
    case that it can actually be used.

  - Whitespace cleanup, as appropriate for a new file with no
    other pending patches.

So other than that minor logging change, no functional updates.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This fixes some bugs in EHCI suspend/resume that joined us over the past
few releases (as usbcore, PCI, pmcore, and other components evolved):

  - Removes suspend and resume recursion from the EHCI driver, getting
    rid of the USB_SUSPEND special casing.

  - Updates the wakeup mechanism to work again; there's a newish usbcore
    call it needs to use.

  - Provide simpler tests for "do we need to restart from scratch", to
    address another case where PCI Vaux was lost.  (In this case it was
    restoring a swsusp snapshot, but there could be others.)

Un-exports a symbol that was temporarily exported.

A notable change from previous version is that this doesn't move
the spinlock init, so there's still a resume/reinit path bug.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Thanks to Andrew for doing the hard work on this.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add .owner initialisation to the device drivers
in drivers/usb/host so that when built as module
the device_driver refers to the owning module
Signed-off-by: NBen Dooks <ben-linux@fluff.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as580) is perhaps the only result from the long discussion I
had with David about his changes to the root-hub suspend/resume code.  It
renames the hub_suspend and hub_resume methods in struct usb_hcd to
bus_suspend and bus_resume.  These are more descriptive names, since the
methods really do suspend or resume an entire USB bus, and less likely to
be confused with the hub_suspend and hub_resume routines in hub.c.

It also takes David's advice about removing the layer of bus glue, where
those methods are called.  And it implements a related change that David
made to the other HCDs but forgot to put into dummy_hcd.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This splits BIOS and PCI specific support out of ehci-hcd.c into
ehci-pci.c.  It follows the model already used in the OHCI driver
so support for non-PCI EHCI controllers can be more easily added.
Signed-off-by: NMatt Porter <mporter@kernel.crashing.org>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

 drivers/usb/host/ehci-hcd.c |  543 ++++++--------------------------------------
 drivers/usb/host/ehci-pci.c |  414 +++++++++++++++++++++++++++++++++
 drivers/usb/host/ehci.h     |    1
 3 files changed, 492 insertions(+), 466 deletions(-)