MIPS FPU emulator: allow Cause bits of FCSR to be writeable by ctc1

In the FPU emulator code of the MIPS, the Cause bits of the FCSR register
are not currently writeable by the ctc1 inst

MIPS FPU emulator: allow Cause bits of FCSR to be writeable by ctc1

In the FPU emulator code of the MIPS, the Cause bits of the FCSR register
are not currently writeable by the ctc1 instruction. In odd corner cases,
this can cause problems. For example, a case existed where a divide-by-zero
exception was generated by the FPU, and the signal handler attempted to
restore the FPU registers to their state before the exception occurred. In
this particular setup, writing the old value to the FCSR register would
cause another divide-by-zero exception to occur immediately. The solution
is to change the ctc1 instruction emulator code to allow the Cause bits of
the FCSR register to be writeable. This is the behaviour of the hardware
that the code is emulating.

This problem was found by Shane McDonald, but the credit for the fix goes
to Kevin Kissell. In Kevin's words:

I submit that the bug is indeed in that ctc_op: case of the emulator. The
Cause bits (17:12) are supposed to be writable by that instruction, but the
CTC1 emulation won't let them be updated by the instruction. I think that
actually if you just completely removed lines 387-388 [...] things would
work a good deal better. At least, it would be a more accurate emulation of
the architecturally defined FPU. If I wanted to be really, really pedantic
(which I sometimes do), I'd also protect the reserved bits that aren't
necessarily writable.

Signed-off-by: Shane McDonald <mcdonald.shane@gmail.com>
To: anemo@mba.ocn.ne.jp
To: kevink@paralogos.com
To: sshtylyov@mvista.com
Patchwork: http://patchwork.linux-mips.org/patch/1205/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

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Merge commit 'v2.6.34-rc7' into perf/nmi

Merge reason: catch up with latest softlockup detector changes.

Merge branch 'x86/asm' into x86/atomic

Merge reason:
Conflict between LOCK_PREFIX_HERE and relative alternatives
pointers

Resolved Conflicts:
arch/x86/include/asm/alternative.h
arch/x86/kernel/

Merge branch 'x86/asm' into x86/atomic

Merge reason:
Conflict between LOCK_PREFIX_HERE and relative alternatives
pointers

Resolved Conflicts:
arch/x86/include/asm/alternative.h
arch/x86/kernel/alternative.c

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

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Merge commit 'v2.6.34-rc5' into oprofile/core

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

Merge branch 'v2.6.34-rc2' into drm-linus

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

Conflicts:
drivers/mtd/nand/sh_flctl.c

Maxim's patch to initialise sysfs attributes depends on the patch w

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

Conflicts:
drivers/mtd/nand/sh_flctl.c

Maxim's patch to initialise sysfs attributes depends on the patch which
actually adds sysfs_attr_init().

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Merge branch 'topic/misc' into topic/usb

Merge branches 'battery-2.6.34', 'bugzilla-10805', 'bugzilla-14668', 'bugzilla-531916-power-state', 'ht-warn-2.6.34', 'pnp', 'processor-rename', 'sony-2.6.34', 'suse-bugzilla-531547', 'tz-check', 'vi

Merge branches 'battery-2.6.34', 'bugzilla-10805', 'bugzilla-14668', 'bugzilla-531916-power-state', 'ht-warn-2.6.34', 'pnp', 'processor-rename', 'sony-2.6.34', 'suse-bugzilla-531547', 'tz-check', 'video' and 'misc-2.6.34' into release

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Merge commit 'v2.6.34-rc1' into for-2.6.35

Merge commit 'v2.6.34-rc1' into for-2.6.35-incoming

Merge commit 'v2.6.34-rc1' into perf/urgent

Conflicts:
tools/perf/util/probe-event.c

Merge reason: Pick up -rc1 and resolve the conflict as well.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

Merge commit 'v2.6.34-rc1' into for-linus

Merge branch 'origin' into devel-stable

Conflicts:
arch/arm/mach-mx2/devices.c
arch/arm/mach-mx2/devices.h
sound/soc/pxa/pxa-ssp.c

Merge branch 'master' of /repos/git/linux-2.6

Conflicts:
net/ipv4/netfilter/nf_nat_core.c
net/netfilter/nf_conntrack_core.c
net/netfilter/nf_conntrack_netlink.c

Signed-off-by: Patrick McHardy <k

Merge branch 'master' of /repos/git/linux-2.6

Conflicts:
net/ipv4/netfilter/nf_nat_core.c
net/netfilter/nf_conntrack_core.c
net/netfilter/nf_conntrack_netlink.c

Signed-off-by: Patrick McHardy <kaber@trash.net>

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Merge branch 'writeback-for-2.6.34' into nfs-for-2.6.34

Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs into for-2.6.34-incoming

Resolve merge conflict in fs/xfs/linux-2.6/xfs_export.c.

Merge branch 'tip/tracing/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/urgent

Merge with mainline to remove plat-omap/Kconfig conflict

Conflicts:
arch/arm/plat-omap/Kconfig

Merge branch 'linus' into core/rcu

Merge reason: Backmerge latest upstream to queue up dependent fix in the
scheduler.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

Merge branch 'master' of /home/davem/src/GIT/linux-2.6/

Conflicts:
drivers/firmware/iscsi_ibft.c

Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus

* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus: (141 commits)
MIPS: Alchemy: defconfig updates
MIPS: A

Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus

* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus: (141 commits)
MIPS: Alchemy: defconfig updates
MIPS: Alchemy: Fix Au1100 ethernet build failure
MIPS: Alchemy: Repair db1500/bosporus builds
MIPS: ARC: Cleanup unused definitions from sgialib.h
MIPS: Cobalt: convert legacy port addresses to GT-64111 bus addresses
MIPS: Alchemy: use 36bit addresses for PCMCIA resources.
MIPS: Cobalt: Fix theoretical port aliasing issue
MIPS: Use ALIGN(x, bytes) instead of __ALIGN_MASK(x, bytes - 1)
MIPS: Crazy spinlock speed test.
MIPS: Optimize spinlocks.
MIPS: Alchemy: devboard PM needs to save CPLD registers.
MIPS: PowerTV: Eliminate duplicate opcode definition macros
MIPS: Lemote 2F: Move printks out of port_access_lock.
MIPS: PNX833x: Convert IRQ controller locks to raw spinlocks.
MIPS: Octeon: Replace spinlock with raw_spinlocks in dma-octeon.c.
MIPS: Octeon: Replace rwlocks in irq_chip handlers with raw_spinlocks.
MIPS: Octeon: Convert octeon_irq_msi_lock to raw spinlock.
MIPS: Loongson: Remove pointless sample_lock from oprofile code.
MIPS: SNI: Convert sni_rm200_i8259A_lock to raw spinlock.
MIPS: i8259: Convert IRQ controller lock to raw spinlock.
...

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Merge commit 'v2.6.33' into perf/core

Merge reason:
__percpu annotations need the corresponding sparse address
space definition upstream.

Conflicts:
tools/perf/util/probe-event.c (trivial)

MIPS: Add accessor functions and bit definitions for c0_PageGrain

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patc

MIPS: Add accessor functions and bit definitions for c0_PageGrain

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/950/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

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MIPS: Decode c0_config4 for large TLBs.

For processors that have more than 64 TLBs, we need to decode both
config1 and config4 to determine the total number TLBs.

Signed-off-by: David Daney <ddaney

MIPS: Decode c0_config4 for large TLBs.

For processors that have more than 64 TLBs, we need to decode both
config1 and config4 to determine the total number TLBs.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/866/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

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