linux-stable.git/arch/powerpc/kernel/exceptions-64e.S, branch linux-4.3.y

powerpc/fsl: Force coherent memory on e500mc derivatives

2015-08-08T04:00:01+00:00

In CoreNet systems it is not allowed to mix M and non-M mappings to the
same memory, and coherent DMA accesses are considered to be M mappings
for this purpose.  Ignoring this has been observed to cause hard
lockups in non-SMP kernels on e6500.

Furthermore, e6500 implements the LRAT (logical to real address table)
which allows KVM guests to control the WIMGE bits.  This means that
KVM cannot force the M bit on the way it usually does, so the guest had
better set it itself.

Signed-off-by: Scott Wood

powerpc/booke: Revert SPE/AltiVec common defines for interrupt numbers

2014-09-22T08:11:31+00:00

Book3E specification defines shared interrupt numbers for SPE and AltiVec
units. Still SPE is present in e200/e500v2 cores while AltiVec is present in
e6500 core. So we can currently decide at compile-time which unit to support
exclusively. As Alexander Graf suggested, this will improve code readability
especially in KVM.

Use distinct defines to identify SPE/AltiVec interrupt numbers, reverting
c58ce397 and 6b310fc5 patches that added common defines.

Signed-off-by: Mihai Caraman 
Acked-by: Scott Wood 
Signed-off-by: Alexander Graf

powerpc: Remove platforms/wsp and associated pieces

2014-06-11T06:35:38+00:00

__attribute__ ((unused))

WSP is the last user of CONFIG_PPC_A2, so we remove that as well.

Although CONFIG_PPC_ICSWX still exists, it's no longer selectable for
any Book3E platform, so we can remove the code in mmu-book3e.h that
depended on it.

Signed-off-by: Michael Ellerman 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Remove dot symbol usage in exception macros

2014-04-23T00:05:19+00:00

STD_EXCEPTION_COMMON, STD_EXCEPTION_COMMON_ASYNC and
MASKABLE_EXCEPTION branch to the handler, so we can remove
the explicit dot symbol and binutils will do the right thing.

Signed-off-by: Anton Blanchard

powerpc: Remove some unnecessary uses of _GLOBAL() and _STATIC()

2014-04-23T00:05:18+00:00

There is no need to create a function descriptor for functions
called locally out of assembly.

Signed-off-by: Anton Blanchard

powerpc: No need to use dot symbols when branching to a function

2014-04-23T00:05:16+00:00

binutils is smart enough to know that a branch to a function
descriptor is actually a branch to the functions text address.

Alan tells me that binutils has been doing this for 9 years.

Signed-off-by: Anton Blanchard

powerpc/booke64: Critical and machine check exception support

2014-03-20T00:57:27+00:00

Add special state saving for critical and machine check exceptions.

Most of this code could be used to handle debug exceptions taken from
kernel space, but actually doing so is outside the scope of this patch.

The various critical and machine check exceptions now point to their
real handlers, rather than hanging the kernel.

Signed-off-by: Scott Wood

powerpc/booke64: Add crit/mc/debug support to EXCEPTION_COMMON

2014-03-20T00:57:17+00:00

Use the proper scratch SPRG and PACA region.  Introduce level-specific
macros to simplify usage and avoid needing to do a bunch of token
pasting throughout EXCEPTION_COMMON().

Now that EXCEPTION_COMMON_DBG() is properly using the debug scratch
register, there's no more need for the caller to move the value to the
GEN scratch first.

Signed-off-by: Scott Wood

powerpc/booke64: Remove ints from EXCEPTION_COMMON

2014-03-20T00:57:16+00:00

The ints parameter was used to optionally insert RECONCILE_IRQ_STATE
into EXCEPTION_COMMON.  However, since it came at the end of
EXCEPTION_COMMON, there was no real benefit for it to be there as
opposed to being called separately by the caller of EXCEPTION_COMMON.

The ints parameter was causing some hassle when trying to add an extra
macro layer.  Besides avoiding that, moving "ints" to the caller makes
the code simpler by:
 - avoiding the asymmetry where INTS_RESTORE_HARD is called separately
by the individual exception, but INTS_DISABLE was not
 - removing the no-op INTS_KEEP
 - not having an unnecessary macro parameter

It also turned out to be necessary to delay the INTS_DISABLE
in the case of special level exceptions until after we saved the
old value of PACAIRQHAPPENED.

Signed-off-by: Scott Wood

powerpc/booke64: Use SPRG7 for VDSO

2014-03-20T00:57:14+00:00

Previously SPRG3 was marked for use by both VDSO and critical
interrupts (though critical interrupts were not fully implemented).

In commit 8b64a9dfb091f1eca8b7e58da82f1e7d1d5fe0ad ("powerpc/booke64:
Use SPRG0/3 scratch for bolted TLB miss & crit int"), Mihai Caraman
made an attempt to resolve this conflict by restoring the VDSO value
early in the critical interrupt, but this has some issues:

 - It's incompatible with EXCEPTION_COMMON which restores r13 from the
   by-then-overwritten scratch (this cost me some debugging time).
 - It forces critical exceptions to be a special case handled
   differently from even machine check and debug level exceptions.
 - It didn't occur to me that it was possible to make this work at all
   (by doing a final "ld r13, PACA_EXCRIT+EX_R13(r13)") until after
   I made (most of) this patch. :-)

It might be worth investigating using a load rather than SPRG on return
from all exceptions (except TLB misses where the scratch never leaves
the SPRG) -- it could save a few cycles.  Until then, let's stick with
SPRG for all exceptions.

Since we cannot use SPRG4-7 for scratch without corrupting the state of
a KVM guest, move VDSO to SPRG7 on book3e.  Since neither SPRG4-7 nor
critical interrupts exist on book3s, SPRG3 is still used for VDSO
there.

Signed-off-by: Scott Wood 
Cc: Mihai Caraman 
Cc: Anton Blanchard 
Cc: Paul Mackerras 
Cc: kvm-ppc@vger.kernel.org