There are some devices (for example Dell Multimedia Keyboard SK-8135) that have
a volume control knob which generates relative events instead of absolute.
hid-input maps them to ABS_VOLUME. HUT pages don't restrict volume to absolute
values.

Adding REL_VOLUME doesn't seem feasible, nothing knows how to handle it. This
patch translates relative ABS_VOLUME events into appropriate number of series
of VOLUME_UP or VOLUME_DOWN events respectively, so that userspace sees the
correct values in the end.

kernel.org bugzilla 5233
Reported-by: NJochen Eisinger <jochen@penguin-breeder.org>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

The keyboard 0x046d/0xc311 needs reset leds quirk
Tested-by: NAntonino Ingargiola <tritemio@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

This keyboard has wireless mouse which has left, middle, right buttons and
2-dimensional scrolling wheel.  Unfornetuly, this wheel reports side scrolling
events and 11 or 12 button events at the same time.

I've wrote a patch to fix this mapping.  I'm not sure if this mapping is proper
for buttons, because , for example, there is no entry for "burn cd" in input.h.

The patch also supress 11 and 12 button events from mouse when you scroll the
wheel left and right.  With this patch, only side scrolling events are
reported.  (This mouse has only 4 buttons and 2D wheel. There is no such
buttons like 11 and 12.)
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

When setting the autocentering of PID devices, PID_DIRECTION_ENABLE is not
being explicitely set to 1. This results in autocentering working only on the
vertical axis when this field is preset to 0.

Fix that by setting it explicitely to 1 when preparing the set_effect report
for autocentering spring effect.
Signed-off-by: NDiogo Kastrup <dk@bighost.com.br>
Signed-off-by: NAnssi Hannula <anssi.hannula@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Lately there have been quite a lot of bug reports against broken devices
which require us to fix their report descriptor in the runtime, before it
is passed to the HID parser. Those devices have eaten quite an amount of
our quirks space, which isn't particularly necessary - the quirks are not
needed after the report descriptor is parsed, and they just consume bits.

Therefore this patch separates the quirks for report descriptor fixup, and
moves their handling into separate code. The quirks are then forgotten as
soon as the report descriptor has been parsed.

Module parameter 'rdesc_quirks' is introduced to be able to modify these
quirks in runtime in a similar way to 'quirks' parameter for ordinary HID
quirks.
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Devices manufactured by NCR have userspace hiddev-based drivers,
which do all the necessary device querying by themselves. The devices
must not be queried directly by the generic HID driver, as reported by
NCR engineers.

Cc: Petr Ostadal <postadal@suse.cz>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Petalynx Maxter remote control [1] 0x18b1/0x0037 emits 0xfa and 0xfc from
consumer page (reserved in HUT 1.12) for back and more keys. It also emits
a few usages from LOGIVENDOR page, which need adding.

Also, this device has broken report descriptor - the reported maximum is too
low - it doesn't contain the range for 'back' and 'more' keys, so we need to
bump it up before the report descriptor is being parsed.

Besides all this, it also requires NOGET quirk.

This patch does so.

[1] http://www.elmak.pl/index.php?option=com_phpshop&page=shop.browse&category_id=14&ext=opis&lang=enSigned-off-by: NJiri Kosina <jkosina@suse.cz>

When comparing usb vs ps2 / testing the keycodes generated for the easy access
keys on my trust (microsoft compatible) keyboard. I noticed the search key
generated the keycode for find when connected through USB. This lead me to
check the consumer page mappings in hid-input.c . And it turns out the the
mapping for ID 0x221 deviates from the HUT standard document:
http://www.usb.org/developers/devclass_docs/Hut1_12.pdf

Currently it is incorrectly mapped to find, whereas it should be mapped to
search. I also added missing bindings for ID 0x21f, the real find and for
0x222, goto.
Signed-off-by: NHans de Goede <j.w.r.degoede@hhs.nl>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

This patch provides support for the Gameron dual psx adaptor.  The
modification  is to add the quirk HID_QUIRK_MULTI_INPUT for this
specific USB device.
Signed-off-by: NJulien Eyries <jeyries@yahoo.fr>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

This patch (as914) replaces a call to flush_scheduled_work() with
cancel_work_sync(), in order to help avoid potential deadlocks.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Make a "menuconfig" out of the Kconfig objects "menu, ..., endmenu",
so that the user can disable all the options in that menu at once
instead of having to disable each option separately.
Signed-off-by: NJan Engelhardt <jengelh@gmx.de>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Microsoft SideWinder GameVoice driver is a trivial device with a few buttons
(0x09 HID usage) and an audio connector, which just forwards the audio input
into oridinary sound card present in the computer.

Despite this fact, the only interface of this device reports itself as a
Telephony/Headset type of HID device. This is apparently incorrect - the device
itself doesn't provide any audio/telephony functionality. This is achieved in
userland application which only needs to receive the button events from the HID
driver.

This patch establishes a new quirk which forces hid-input to claim a device it
will otherwise leave untouched.
Reported-by: NTomas Carnecky <tom@dbservice.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Chicony KU-0418 (aka Saitek PZ08AU gaming keyboard) has a separate
"tactical pad" with 11 non-functional buttons - they generate usage
codes from 0xff00 (MSVENDOR) usage page. Special case handling for
this keyboard added, so no later clash with MSVENDOR mappings is going
to occur.

Pointed out in bugzilla #7352
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

There have been many reports recently about broken HID devices, the
diagnosis of which required users to recompile their kernels in order
to be able to provide debugging output needed for coding a quirk for
a particular device.

This patch makes CONFIG_HID_DEBUG default y if !EMBEDDED and makes it
possible to control debugging output produced by HID code by supplying
'debug=1' module parameter.
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Woo-hoo. I'm sure somebody will report a "this doesn't compile, and
I have a new root exploit" five minutes after release, but it still
feels good ;)
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* master.kernel.org:/pub/scm/linux/kernel/git/bart/ide-2.6:
  qd65xx: fix PIO mode selection
  sis5513: adding PCI-ID

Commit 1c710c89 added the utimensat()
system call, but didn't handle the case of checking for the writability
of the target right, when the target was a file descriptor, not a
filename.

We cannot use vfs_permission(MAY_WRITE) for that case, and need to
simply check whether the file descriptor is writable.  The oops from
using the wrong function was noticed and narrowed down by Markus
Trippelsdorf.

Cc: Ulrich Drepper <drepper@redhat.com>
Cc: Markus Trippelsdorf <markus@trippelsdorf.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: NAl Viro <viro@ftp.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix a post-2.6.21 regression.

read_cache_page_async() has two invocations of mark_page_accessed() which will
launch pages right onto the active list.

Remove the first one, keeping the latter one.  This avoids marking unwanted
pages active (in the retry loop).
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NNick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

PIO4 is a maximum PIO mode supported by a driver.  Using "255" as a max_mode
argument to ide_get_best_pio_mode() could result in wrong timings being used
by a driver (for "pio" equal to 5) or OOPS (for "pio" values > 5 && < 255).
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Acked-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Reviewed-by: NAlan Cox <alan@lxorguk.ukuu.org.uk>

The SiS966 has one additional PCI-ID 1180.

If the chipset is using this PCI-ID, the primary channel is connected to the
first PATA-port. The secondary channel is connected to SATA-ports in IDE
emulation mode.  The legacy IO-ports are used.

The including of the PCI-ID into pata_sis is not sufficient, because the legacy
driver in drivers/ide is initialized before pata_sis.
Signed-off-by: NUwe Koziolek <uwe.koziolek@gmx.net>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

The dependency of DLM on SYSFS got lost in
commit 6ed7257b resulting in the
following compile error with CONFIG_DLM=y, CONFIG_SYSFS=n:

<--  snip  -->

...
  LD      .tmp_vmlinux1
fs/built-in.o: In function `dlm_lockspace_init':
/home/bunk/linux/kernel-2.6/linux-2.6.22-rc6-mm1/fs/dlm/lockspace.c:231: undefined reference to `kernel_subsys'
fs/built-in.o: In function `configfs_init':
/home/bunk/linux/kernel-2.6/linux-2.6.22-rc6-mm1/fs/configfs/mount.c:143: undefined reference to `kernel_subsys'
make[1]: *** [.tmp_vmlinux1] Error 1

<--  snip  -->
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The printk level in this printk is bogus, as the previous printk
didn't have a terminating \n resulting in ..

Intel E7520/7320/7525 detected.<6>Disabling irq balancing and affinity

It also never printed a \n at all in the case where we didn't do
the quirk.

Change it to only make noise if it actually does something useful.
Signed-off-by: NDave Jones <davej@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch fixes the following 2.6.22 regression with CONFIG_KALLSYMS=n:

<--  snip  -->

...
  CC      arch/m32r/kernel/traps.o
In file included from /home/bunk/linux/kernel-2.6/linux-2.6.22-rc6-mm1/arch/m32r/kernel/traps.c:14:
/home/bunk/linux/kernel-2.6/linux-2.6.22-rc6-mm1/include/linux/kallsyms.h: In function 'lookup_symbol_name':
/home/bunk/linux/kernel-2.6/linux-2.6.22-rc6-mm1/include/linux/kallsyms.h:66: error: 'ERANGE' undeclared (first use in this function)
/home/bunk/linux/kernel-2.6/linux-2.6.22-rc6-mm1/include/linux/kallsyms.h:66: error: (Each undeclared identifier is reported only once
/home/bunk/linux/kernel-2.6/linux-2.6.22-rc6-mm1/include/linux/kallsyms.h:66: error: for each function it appears in.)
/home/bunk/linux/kernel-2.6/linux-2.6.22-rc6-mm1/include/linux/kallsyms.h: In function 'lookup_symbol_attrs':
/home/bunk/linux/kernel-2.6/linux-2.6.22-rc6-mm1/include/linux/kallsyms.h:71: error: 'ERANGE' undeclared (first use in this function)
make[2]: *** [arch/m32r/kernel/traps.o] Error 1

<--  snip  -->
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When cleaning up HIDP sessions, we currently close the ACL connection
before deregistering the input device. Closing the ACL connection
schedules a workqueue to remove the associated objects from sysfs, but
the input device still refers to them -- and if the workqueue happens to
run before the input device removal, the kernel will oops when trying to
look up PHYSDEVPATH for the removed input device.

Fix this by deregistering the input device before closing the
connections.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

kmem_cache_open is static. EXPORT_SYMBOL was leftover from some earlier
time period where kmem_cache_open was usable outside of slub.

(Fixes powerpc build error)
Signed-off-by: NChrsitoph Lameter <clameter@sgi.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

davem kindly moved the list from osdl to vger.
Signed-of-by: Nmaximilian attems <max@stro.at>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Writing to MSR 0x51400017 forces a hard reset on CS5536-based machines,
this has the reboot fixup do just that if such a board is detected.
Acked-by: NJordan Crouse <jordan.crouse@amd.com>
Signed-off-by: NAndres Salomon <dilinger@debian.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6:
  [NETPOLL]: Fixups for 'fix soft lockup when removing module'
  [NET]: net/core/netevent.c should #include <net/netevent.h>
  [NETFILTER]: nf_conntrack_h323: add checking of out-of-range on choices' index values
  [NET] skbuff: remove export of static symbol
  SCTP: Add scope_id validation for link-local binds
  SCTP: Check to make sure file is valid before setting timeout
  SCTP: Fix thinko in sctp_copy_laddrs()

* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
  [MIPS] Fix scheduling latency issue on 24K, 34K and 74K cores
  [MIPS] Add macros to encode processor revisions.
  [MIPS] RM7000: Enable ICACHE_REFILLS_WORKAROUND_WAR.
  [MIPS] SMTC: Fix cut'n'paste bug in Kconfig.debug
  [MIPS] Change libgcc-style functions from lib-y to obj-y
  [MIPS] Fix timer/performance interrupt detection
  [MIPS] AP/SP: Avoid triggering the 34K E125 performance issue
  [MIPS] 64-bit TO_PHYS_MASK macro for RM9000 processors

Line up the vmstat_text with zone_stat_item

enum zone_stat_item {
	/* First 128 byte cacheline (assuming 64 bit words) */
	NR_FREE_PAGES,
	NR_INACTIVE,
	NR_ACTIVE,

We current have nr_active and nr_inactive reversed.

[ "OK with patch, though using initializers canbe handy to prevent such
   things in future:

	static const char * const vmstat_text[] = {
		[NR_FREE_PAGES] = "nr_free_pages",
		..."
							 - Alexey ]
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In 7d12e780 David Howells performed
this evolution:
 "IRQ: Maintain regs pointer globally rather than passing to IRQ handlers"

He correctly updated many of the function definitions that were using this
extra regs pointer parameter but forgot to update some caller sites of
those functions.  The reason the modifications was not properly done on all
drivers is that some drivers were rarely compiled because they are for
AMIGA, or that some code sites were inside #ifdefs where the option is not
set or inside #if 0.

Here is the semantic patch that found the occurences
and fixed the problem.

@ rule1 @
identifier fn;
identifier irq, dev_id;
typedef irqreturn_t;
@@

static irqreturn_t fn(int irq, void *dev_id)
{
   ...
}

@@
identifier rule1.fn;
expression E1, E2, E3;
@@

 fn(E1, E2
-   ,E3
   )
Signed-off-by: NYoann Padioleau <padator@wanadoo.fr>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

o Commit 1833d6bc broke the build if
  compiled with CONFIG_ES7000=y and CONFIG_X86_GENERICARCH=n

arch/i386/kernel/built-in.o(.init.text+0x4fa9): In function `acpi_parse_madt':
: undefined reference to `acpi_madt_oem_check'
arch/i386/kernel/built-in.o(.init.text+0x7406): In function `smp_read_mpc':
: undefined reference to `mps_oem_check'
arch/i386/kernel/built-in.o(.init.text+0x8990): In function
`connect_bsp_APIC':
: undefined reference to `enable_apic_mode'
make: *** [.tmp_vmlinux1] Error 1

o Fix the build issue. Provided the definitions of missing functions.

o Don't have ES7000 machine. Only compile tested.

Cc: Len Brown <lenb@kernel.org>
Cc: Natalie Protasevich <protasnb@gmail.com>
Cc: Roland Dreier <rolandd@cisco.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When we enable the SMCf010 IR device, the Toshiba Portege 4000 BIOS claims
the device is working, but it really isn't configured correctly.  The BIOS
*will* configure it, but only if we call _SRS after (1) reversing the order
of the SIR and FIR I/O port regions and (2) changing the IRQ from
active-high to active-low.

This patch addresses the 2.6.22 regression:
    "no irda0 interface (2.6.21 was OK), smsc does not find chip"

I tested this on a Portege 4000.  The smsc-ircc2 driver correctly detects
the device, and "irattach irda0 -s && irdadump" shows transmitted and
received packets.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Andrey Borzenkov <arvidjaar@mail.ru>
Cc: Samuel Ortiz <samuel@sortiz.org>
Cc: "Linus Walleij (LD/EAB)" <linus.walleij@ericsson.com>
Cc: Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
Cc: Adam Belay <ambx1@neo.rr.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When calling a semctl(IPC_STAT) without IPC_64 the check if the memory is
unevaluated.  This patch fixes this.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A bug in headers_install for ARCH=x86_64 yields an asm/ directory full of
files all of which are using the same #ifdef guard, "__ASM_STUB_" with no
postfix.  So the second and later asm files #included in the same C file
(often through standard headers like ioctl.h) yields no symbols.

Strangeness with the Ubuntu 'tell me if I support something that's not
explcitly mentioned in POSIX, and I'll strip it out' shell, I believe.

We don't need the 'export' but we do need a semicolon at the end of the
FNAME line:
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>
Signed-off-by: NRob Landley <rob@landley.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Processors synchronization in set_mtrr requires the .gate field to be set
after .count field is properly initialized.  Without an explicit barrier,
the compiler was reordering those memory stores.  That was sometimes
causing a processor (in ipi_handler) to see the .gate change and decrement
.count before the latter is set by set_mtrr() (which then hangs in a
infinite loop with irqs disabled).
Signed-off-by: NLoic Prylli <loic@myri.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The commit 635cf99a introduced a
regression.  Executing a ptrace single step after certain int80
accesses will infinitely loop and never advance the PC.

The TIF_SINGLESTEP check should be done on the return from the syscall
and not before it.

I loops on each single step on the pop right after the int80 which writes out
to the console.  At that point you can issue as many single steps as you want
and it will not advance any further.

The test case is below:

/* Test whether singlestep through an int80 syscall works.
 */
#define _GNU_SOURCE
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/ptrace.h>
#include <sys/wait.h>
#include <sys/mman.h>
#include <asm/user.h>
#include <string.h>

static int child, status;
static struct user_regs_struct regs;

static void do_child()
{
	char str[80] = "child: int80 test\n";

	ptrace(PTRACE_TRACEME, 0, 0, 0);
	kill(getpid(), SIGUSR1);
	write(fileno(stdout),str,strlen(str));
	asm ("int $0x80" : : "a" (20)); /* getpid */
}

static void do_parent()
{
	unsigned long eip, expected = 0;
again:
	waitpid(child, &status, 0);
	if (WIFEXITED(status) || WIFSIGNALED(status))
		return;

	if (WIFSTOPPED(status)) {
		ptrace(PTRACE_GETREGS, child, 0, &regs);
		eip = regs.eip;
		if (expected)
			fprintf(stderr, "child stop @ %08lx, expected %08lx %s\n",
					eip, expected,
					eip == expected ? "" : " <== ERROR");

		if (*(unsigned short *)eip == 0x80cd) {
			fprintf(stderr, "int 0x80 at %08x\n", (unsigned int)eip);
			expected = eip + 2;
		} else
			expected = 0;

		ptrace(PTRACE_SINGLESTEP, child, NULL, NULL);
	}
	goto again;
}

int main(int argc, char * const argv[])
{
	child = fork();
	if (child)
		do_parent();
	else
		do_child();
	return 0;
}
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: <stable@kernel.org>
Cc: Chuck Ebbert <76306.1226@compuserve.com>
Acked-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

elf_core_dump() supports dumping arch specific ELF notes, via the #define
ELF_CORE_WRITE_EXTRA_NOTES.  Currently the only user of this is the powerpc
spu coredump code.

There is a bug in the handling of foffset WRT the arch notes, which causes
us to erroneously increment foffset by the size of the arch notes, leaving
a block of zeroes in the file, and causing all subsequent data in the file
to be at <supposed position> + <arch note size>.  eg:

  LOAD  0x050000 0x00100000 0x00000000 0x20000 0x20000 R E 0x10000

Tells us we should have a chunk of data at 0x50000.  The truth is the data
is at 0x90dbc = 0x50000 + 0x40dbc (the size of the arch notes).

This bug prevents gdb from reading the core file correctly.

The simplest fix is to simply remember the size of the arch notes, and add
it to foffset after we've written the arch notes.  The only drawback is
that if the arch code doesn't write as many bytes as it said it would, we
end up with a broken core dump again.  For now I think that's a reasonable
requirement.

Tested on a Cell blade, gdb no longer complains about the core file being
bogus.

While I'm here I should point out that the spu coredump code does not work
if we're dumping to a pipe - we'll have to wait for 23 to fix that.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The idle loop goes to sleep using the WAIT instruction if !need_resched().
This has is suffering from from a race condition that if if just after
need_resched has returned 0 an interrupt might set TIF_NEED_RESCHED but
we've just completed the test so go to sleep anyway.  This would be
trivial to fix by just disabling interrupts during that sequence as in:

        local_irq_disable();
        if (!need_resched())
                __asm__("wait");
        local_irq_enable();

but the processor architecture leaves it undefined if a processor calling
WAIT with interrupts disabled will ever restart its pipeline and indeed
some processors have made use of the freedom provided by the architecture
definition.  This has been resolved and the Config7.WII bit indicates that
the use of WAIT is safe on 24K, 24KE and 34K cores.  It also is safe on
74K starting revision 2.1.0 so enable the use of WAIT with interrupts
disabled for 74K based on a c0_prid of at least that.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>