linux-toradex.git/arch/powerpc/kernel, branch v2.6.27.48

powerpc: Handle VSX alignment faults correctly in little-endian mode

2010-01-18T18:34:03+00:00

commit bb7f20b1c639606def3b91f4e4aca6daeee5d80a upstream.

This patch fixes the handling of VSX alignment faults in little-endian
mode (the current code assumes the processor is in big-endian mode).

The patch also makes the handlers clear the top 8 bytes of the register
when handling an 8 byte VSX load.

This is based on 2.6.32.

Signed-off-by: Neil Campbell 
Acked-by: Michael Neuling 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc: Disable VSX or current process in giveup_fpu/altivec

2010-01-18T18:34:01+00:00

commit 7e875e9dc8af70d126fa632446e967327ac3fdda upstream.

When we call giveup_fpu, we need to need to turn off VSX for the
current process.  If we don't, on return to userspace it may execute a
VSX instruction before the next FP instruction, and not have its
register state refreshed correctly from the thread_struct.  Ditto for
altivec.

This caused a bug where an unaligned lfs or stfs results in
fix_alignment calling giveup_fpu so it can use the FPRs (in order to
do a single <-> double conversion), and then returning to userspace
with FP off but VSX on.  Then if a VSX instruction is executed, before
another FP instruction, it will proceed without another exception and
hence have the incorrect register state for VSX registers 0-31.

   lfs unaligned   <- alignment exception turns FP off but leaves VSX on

   VSX instruction <- no exception since VSX on, hence we get the
                      wrong VSX register values for VSX registers 0-31,
                      which overlap the FPRs.

Signed-off-by: Michael Neuling 
Signed-off-by: Paul Mackerras 
Signed-off-by: Greg Kroah-Hartman

powerpc/pseries: Fix to handle slb resize across migration

2009-09-24T15:47:37+00:00

commit 46db2f86a3b2a94e0b33e0b4548fb7b7b6bdff66 upstream.

The SLB can change sizes across a live migration, which was not
being handled, resulting in possible machine crashes during
migration if migrating to a machine which has a smaller max SLB
size than the source machine. Fix this by first reducing the
SLB size to the minimum possible value, which is 32, prior to
migration. Then during the device tree update which occurs after
migration, we make the call to ensure the SLB gets updated. Also
add the slb_size to the lparcfg output so that the migration
tools can check to make sure the kernel has this capability
before allowing migration in scenarios where the SLB size will change.

BenH: Fixed #include  ->  to avoid
      breaking ppc32 build

Signed-off-by: Brian King 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc: Sanitize stack pointer in signal handling code

2009-05-02T17:24:48+00:00

This has been backported to 2.6.27.x from commit efbda86098 in Linus' tree.

On powerpc64 machines running 32-bit userspace, we can get garbage bits in the
stack pointer passed into the kernel.  Most places handle this correctly, but
the signal handling code uses the passed value directly for allocating signal
stack frames.

This fixes the issue by introducing a get_clean_sp function that returns a
sanitized stack pointer.  For 32-bit tasks on a 64-bit kernel, the stack
pointer is masked correctly.  In all other cases, the stack pointer is simply
returned.

Additionally, we pass an 'is_32' parameter to get_sigframe now in order to
get the properly sanitized stack.  The callers are know to be 32 or 64-bit
statically.

Signed-off-by: Josh Boyer 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc: Fix load/store float double alignment handler

2009-03-17T00:52:56+00:00

commit 49f297f8df9adb797334155470ea9ca68bdb041e upstream.

When we introduced VSX, we changed the way FPRs are stored in the
thread_struct.  Unfortunately we missed the load/store float double
alignment handler code when updating how we access FPRs in the
thread_struct.

Below fixes this and merges the little/big endian case.

Signed-off-by: Michael Neuling 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc/vsx: Fix VSX alignment handler for regs 32-63

2009-02-20T22:36:54+00:00

commit 26456dcfb8d8e43b1b64b2a14710694cf7a72f05 upstream.

Fix the VSX alignment handler for VSX registers > 32.  32-63 are stored
in the VMX part of the thread_struct not the FPR part.

Signed-off-by: Michael Neuling 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc: Fix swapcontext system for VSX + old ucontext size

2009-02-17T17:46:16+00:00

commit 16c29d180becc5bdf92fd0fc7314a44a671b5f4e upstream.

Since VSX support was added, we now have two sizes of ucontext_t;
the older, smaller size without the extra VSX state, and the new
larger size with the extra VSX state.  A program using the
sys_swapcontext system call and supplying smaller ucontext_t
structures will currently get an EINVAL error if the task has
used VSX (e.g. because of calling library code that uses VSX) and
the old_ctx argument is non-NULL (i.e. the program is asking for
its current context to be saved).  Thus the program will start
getting EINVAL errors on calls that previously worked.

This commit changes this behaviour so that we don't send an EINVAL in
this case.  It will now return the smaller context but the VSX MSR bit
will always be cleared to indicate that the ucontext_t doesn't include
the extra VSX state, even if the task has executed VSX instructions.

Both 32 and 64 bit cases are updated.

[paulus@samba.org - also fix some access_ok() and get_user() calls]

Thanks to Ben Herrenschmidt for noticing this problem.

Signed-off-by: Michael Neuling 
Signed-off-by: Paul Mackerras 
Cc: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc/virtex5: Fix Virtex5 machine check handling

2008-12-13T23:29:34+00:00

commit 640d17d60e83401e10e66a0ab6e9e2d6350df656 upstream.

The 440x5 core in the Virtex5 uses the 440A type machine check
(ie, they have MCSRR0/MCSRR1). They thus need to call the
appropriate fixup function to hook the right variant of the
exception.

Without this, all machine checks become fatal due to loss
of context when entering the exception handler.

Signed-off-by: Grant Likely 
Signed-off-by: Josh Boyer 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

2008-09-30T15:40:46+00:00

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc: Fix failure to shutdown with CPU hotplug
  powerpc: Fix PCI in Holly device tree

powerpc: Fix failure to shutdown with CPU hotplug

2008-09-30T03:25:06+00:00

I tracked down the shutdown regression to CPUs not dying
when being shut down during power-off. This turns out to
be due to the system_state being SYSTEM_POWER_OFF, which
this code doesn't take as a valid state for shutting off
CPUs in.

This has never made sense to me, but when I added hotplug
code to implement hibernate I only "made it work" and did
not question the need to check the system_state. Thomas
Gleixner helped me dig, but the only thing we found is
that it was added with the original commit that added CPU
hotplug support.

Signed-off-by: Johannes Berg 
Acked-by: Joel Schopp 
Signed-off-by: Benjamin Herrenschmidt