We actually have two separate bad bugs

1. The read_lock implementation spins with disabled interrupts.  This is
completely wrong
2. Our spin_lock_irqsave should check to see if interrupts were enabled
before the call and re-enable interrupts around the inner spin loop.

The problem is that if we spin with interrupts off, we can't receive
IPIs. This has resulted in a bug where SMP machines suddenly spit
smp_call_function timeout messages and hang.

The scenario I've caught is

CPU0 does a flush_tlb_all holding the vmlist_lock for write.
CPU1 tries a cat of /proc/meminfo which tries to acquire vmlist_lock for
     read
CPU1 is now spinning with interrupts disabled
CPU0 tries to execute a smp_call_function to flush the local tlb caches

This is now a deadlock because CPU1 is spinning with interrupts disabled
and can never receive the IPI
Signed-off-by: NJames Bottomley <jejb@parisc-linux.org>
Signed-off-by: NKyle McMartin <kyle@parisc-linux.org>

This really only adds them for the machines I can check SMP on, which
is CPU interrupts and IOSAPIC (so not any of the GSC based machines).

With this patch, irqbalanced can be used to maintain irq balancing.
Unfortunately, irqbalanced is a bit x86 centric, so it doesn't do an
incredibly good job, but it does work.
Signed-off-by: NJames Bottomley <jejb@parisc-linux.org>
Signed-off-by: NKyle McMartin <kyle@parisc-linux.org>

Since irq.c uses smp_send_all_nop, we must define it for UP builds
as well. Make it a static inline so it gets optimized away. This forces
irq.c to include <asm/smp.h> though.
Signed-off-by: NKyle McMartin <kyle@parisc-linux.org>

Fix our interrupts not to use smp_call_function

On K and D class smp, the generic code calls this under an irq
spinlock, which causes the WARN_ON() message in smp_call_function()
(and is also illegal because it could deadlock).

The fix is to use a new scheme based on the IPI_NOP.
Signed-off-by: NJames Bottomley <jejb@parisc-linux.org>
Signed-off-by: NKyle McMartin <kyle@parisc-linux.org>

The second __const_sigaddset() should have been a sigdelset..  Compile
trouble noted by Greg K-H.
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Due to incomplete memory constraints, gcc would miscompile code with
sigaddset on i386 if sig arg was const.

A quote form Jakub to make the issue clear:

 "You need either
	__asm__("btsl %1,%0" : "+m"(*set) : "Ir"(_sig-1) : "cc");
  or
	__asm__("btsl %1,%0" : "=m"(*set) : "Ir"(_sig-1), "m"(*set) : "cc");
  because the btsl instruction doesn't just set the memory to some
  value, but needs to read its previous content as well.  If you don't
  tell that fact to GCC, GCC is of course free to optimize as if the asm
  was just setting the value and not depended on the previous value."
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

    
There is no definition for seadint_init() and the unprotected prototype
breaks compilation of assembler files.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NArnaud Giersch <arnaud.giersch@free.fr>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

    
Add const qualifier to parameter addr of writes##bwlq.
Signed-off-by: NArnaud Giersch <arnaud.giersch@free.fr>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

    
Add __iomem qualifier to crime and mace pointers.
Signed-off-by: NArnaud Giersch <arnaud.giersch@free.fr>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

    
Fix, complete, and indent IP32 parport definitions.
Definition were wrong for CTXINUSE and DMACTIVE (1-bit shift).
Add macros DATA_BOUND, DATALEN_SHIFT, and CTRSHIFT.
Signed-off-by: NArnaud Giersch <arnaud.giersch@free.fr>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NYoichi Yuasa <yuasa@hh.iij4u.or.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

In the old days when arm26/arm32 was combined into the same
architecture, proc-fns.h provided the xchg implementation for
arm26 CPUs.  Since we no longer combine these two, this include
is no longer required.  Remove it.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Since atomic.h does not include types.h, u32 may not be defined.
Since atomics are supposed to work on unsigned long quantities,
use unsigned long instead.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Unfortunately, using PAGE_SHIFT in asm/arch/memory.h is unsafe, and we
can't include asm/page.h into this file because then we have a circular
dependency.  Move the offending code to arch/arm/common/sa1111.c
instead.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

atomic.h, bitops.h and mmu_context.h are using likely/unlikely.
thread_info.h uses __attribute_const__.  Hence these files require
linux/compiler.h to be included.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Nicolas Pitre

If 'old' and 'oldval' are different then 'res' never gets set.  In that
case, if ever %0 happened to contain anything but zero (rather likely)
then the code will loop forever (or until another CPU just come along
and change the atomic value to match 'old' which is rather unlikely).
Signed-off-by: NNicolas Pitre <nico@cam.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Rationalise hardware.h include.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Move __io_address to arch-realview/hardware.h, drop core.h from platsmp.c
and localtimer.c, and include asm/io.h where required.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Based upon a patch by Guido Guenther <agx@sigxcpu.org>.

Some of these ioctls had embedded time_t objects
or pointers, so needed translation.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The vDSO functions should have the same calling convention as a syscall.
Unfortunately, they currently don't set the cr0.so bit which is used to
indicate an error. This patch makes them clear this bit unconditionally
since all functions currently succeed. The syscall fallback done by some
of them will eventually override this if the syscall fails.

This also changes the symbol version of all vdso exports to make sure
glibc can differenciate between old and fixed calls for existing ones
like __kernel_gettimeofday.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

page_to_virt and lowmem_page_address provided equiavlent functionality
so use the more standard lowmem_page_address

This also addresses build issue in ARCH=powerpc since page_to_virt()
has been removed from include/asm-powerpc/page.h
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

I discovered that in some cases (PowerMac for example) we wouldn't
properly map the PCI IO space on recent kernels. In addition, the code
for initializing PCI host bridges was scattered all over the place with
some duplication between platforms.

This patch fixes the problem and does a small cleanup by creating a
pcibios_alloc_controller() in pci_64.c that is similar to the one in
pci_32.c (just takes an additional device node argument) that takes care
of all the grunt allocation and initialisation work. It should work for
both boot time and dynamically allocated PHBs.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

From Joe Perches
Signed-off-by: NStephen Hemminger <shemminger@osdl.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NMiles Bader <miles@gnu.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NMiles Bader <miles@gnu.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Make sysctl.h (again) useable from userspace
Signed-off-by: NHarald Welte <laforge@netfilter.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NJochen Friedrich <jochen@scram.de>
Acked-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is needed for large multinode IBM systems which have a sparse
APIC space in clustered mode, fully covering the available 8 bits.

The previous kernels would limit the local APIC number to 127,
which caused it to reject some of the CPUs at boot.

I increased the maximum and shrunk the apic_version array a bit
to make up for that (the version is only 8 bit, so don't need
an full int to store)

Cc:  Chris McDermott <lcm@us.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Keeping this function does not makes sense because it's a copied (and
buggy) copy of sys_time.  The only difference is that now.tv_sec (which is
a time_t, i.e.  a 64-bit long) is copied (and truncated) into a int
(32-bit).

The prototype is the same (they both take a long __user *), so let's drop
this and redirect it to sys_time (and make sure it exists by defining
__ARCH_WANT_SYS_TIME).

Only disadvantage is that the sys_stime definition is also compiled (may be
fixed if needed by adding a separate __ARCH_WANT_SYS_STIME macro, and
defining it for all arch's defining __ARCH_WANT_SYS_TIME except x86_64).
Acked-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The current value was correct before the introduction of Intel EM64T support -
but now L1_CACHE_SHIFT_MAX can be less than L1_CACHE_SHIFT, which _is_ funny!

Between the few users of ____cacheline_maxaligned_in_smp, we also have (for
example) rcu_ctrlblk, and struct zone, with zone->{lru_,}lock.  I.e.  we have
a lot of excess cacheline bouncing on them.

No correctness issues, obviously.  So this could even be merged for 2.6.14
(I'm not a fan of this idea, though).

CC: Andi Kleen <ak@suse.de>
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Not needed since x86-64 always uses the spinlock based rwsems.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>