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)

[ ... when you have an editor set to remind you of whitespace bugs ... ]

Cosmetic EHCI changes: remove end-of-line whitespace, spaces before tabs.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This updates the EHCI driver by adding an improved scheduler for the
transaction translators, found in USB 2.0 hubs and used for low and
full speed devices.

 - adds periodic_tt_usecs() and some helper functions, which does
   the same thing that "periodic_usecs" does, except on the other
   side of the TT, i.e.  it calculates the low/fullspeed bandwidth
   usage instead of highspeed.

 - adds a tt_available() function which is the new implementation
   of what tt_no_collision() does ... while tt_no_collision() ensures
   that each TT handles only 1 periodic transfer at a time (a very
   pessimistic approach) this version instead tracks bandwidth and
   allows each TT to handle as many transfers as will fit on each TT's
   downstream bus (closer to best-case).

The new scheduler is selected by a config option, marked as EXPERIMENTAL
so it can be tested (and more broadly reviewed) for a while until it
seems safe to remove the original scheduler.
Signed-off-by: NDan Streetman <ddstreet@ieee.org>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Signed-off-by: NEric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as640) removes several put_device and the corresponding
get_device calls from the USB core and HCDs.  Some of the puts were done
in atomic contexts, and none of them are needed since the core now
guarantees that every endpoint will be disabled and every URB completed
before a USB device is released.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Acked-by: NDavid Brownell <david-b@pacbell.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch replaces the split ISO raw_mask calculation code in the
iso_stream_init() function that computed incorrect numbers of high
speed transactions for both input and output transfers.

In the output case, it added a superfluous start-split transaction for
all maxmimum packet sizes that are a multiple of 188.

In the input case, it forgot to add complete-split transactions for all
microframes covered by the full speed transaction, and the additional
complete-split transaction needed for the case when full speed data
starts arriving near the end of a microframe.

These changes don't affect the lack of full speed bandwidth, but at
least it removes the MMF errors that the HC raised with some input
streams.
Signed-off-by: NClemens Ladisch <clemens@ladisch.de>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Fix sparse warning:
drivers/usb/host/ehci-hcd.c:719:35: warning: incorrect type in argument 3 (different base types)
drivers/usb/host/ehci-hcd.c:719:35:    expected unsigned int [unsigned] mem_flags
drivers/usb/host/ehci-hcd.c:719:35:    got restricted unsigned int [usertype] mem_flags
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch adds a reinitializion for the uf variable that got modified
by the preceding start-split bandwidth check.
Signed-off-by: NClemens Ladisch <clemens@ladisch.de>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.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>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This adds the field tt_usecs to ehci_qh and ehci_iso_stream, and sets it
appropriately when setting them up as periodic endpoints.  It records
the transation translator's think_time (added in last patch) plus the
downstream (i.e. low or full speed) bustime of the transfer associated
with each interrupt or iso frame, as calculated by usb_calc_bus_time.
Signed-off-by: NDan Streetman <ddstreet@ieee.org>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch converts kcalloc(1, ...) calls to use the new kzalloc() function.
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch has a one line oops fix, plus related cleanups.

 - The bugfix uses microframe scheduling data given to the hardware to
   test "is this a periodic QH", rather than testing for nonzero period.
   (Prevents an oops by providing the correct answer.)

 - The cleanup going along with the patch should make it clearer what's
   going on whenever those bitfields are accessed.

The bug came about when, around January, two new kinds of EHCI interrupt
scheduling operation were added, involving both the high speed (24 KBytes
per millisec) and low/full speed (1-64 bytes per millisec) microframe
scheduling.  A driver for the Edirol UA-1000 Audio Capture Unit ran into
the oops; it used one of the newly supported high speed modes.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Greg,

This patch fixes the kmalloc() flags argument type in USB
subsystem; hopefully all of its occurences. The patch was
made against patch-2.6.12-git2 from Jun 20.

Cleanup of flags for kmalloc() in USB subsystem.
Signed-off-by: NOlav Kongas <ok@artecdesign.ee>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The itd_patch() function is responsible for allocating entries in the
buffer page pointer list of the iTD.  Particularly, a new page pointer
is needed every time when buffer data crosses a page boundary.

However, there is a bug in the allocation logic: the function does not
allocate a new entry when the current transaction is the first
transaction in the iTD (as indicated by first!=0).

The consequence is that, when the data of the first transaction begins
somewhere at the end of a page so that it actually does cross the page
boundary, no new page pointer is allocated.  This means that the data
at the end of the first transaction (beyond the page boundary) will be
accessed by the HC using the second page pointer, which is zero.
Furthermore, the first page pointer will be later overwritten by the
page pointers of the other transactions, which will garble it because
the value is or-ed into the iTD field.

All this particular check (for !first) does is cause incorrect
behaviour, so it should be entirely removed (and with it the variable
first that is not used for anything else).
Signed-off-by: NClemens Ladisch <clemens@ladisch.de>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch includes minor "sparse -Wbitwise" updates for the PCI based
HCDs.  Almost all of them involve just changing the second parameter of the
suspend() method to a pm_message_t ...  the others relate to how the EHCI
code walks in-memory data structures.  (There's a minor bug fixed there too
...  affecting the big-endian sysfs async schedule dump.)
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>


Index: gregkh-2.6/drivers/usb/core/hcd.h
===================================================================

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!