linux-toradex.git/include/asm-powerpc/cputable.h, branch v2.6.24.2

[POWERPC] Avoid unpaired stwcx. on some processors

2007-11-13T05:22:43+00:00

The context switch code in the kernel issues a dummy stwcx. to clear the
reservation, as recommended by the architecture.  However, some processors
can have issues if this stwcx to address A occurs while the reservation
is already held to a different address B.  To avoid this problem, the dummy
stwcx. needs to be paired with a dummy lwarx to the same address.

This adds the dummy lwarx, and creates a cpu feature bit to indicate
which cpus are affected.  Tested on mpc8641_hpcn_defconfig in
arch/powerpc; build tested in arch/ppc.

Signed-off-by: Becky Bruce 
Signed-off-by: Paul Mackerras

[POWERPC] Add 1TB workaround for PA6T

2007-10-17T12:30:09+00:00

PA6T has a bug where the slbie instruction does not honor the large
segment bit.  As a result, we have to always use slbia when switching
context.

We don't have to worry about changing the slbie's during fault processing,
since they should never be replacing one VSID with another using the
same ESID.  I.e. there's no risk for inserting duplicate entries due to a
failed slbie of the old entry.  So as long as we clear it out on context
switch we should be fine.

Signed-off-by: Olof Johansson 
Signed-off-by: Paul Mackerras

[POWERPC] Use 1TB segments

2007-10-12T04:05:17+00:00

This makes the kernel use 1TB segments for all kernel mappings and for
user addresses of 1TB and above, on machines which support them
(currently POWER5+, POWER6 and PA6T).

We detect that the machine supports 1TB segments by looking at the
ibm,processor-segment-sizes property in the device tree.

We don't currently use 1TB segments for user addresses < 1T, since
that would effectively prevent 32-bit processes from using huge pages
unless we also had a way to revert to using 256MB segments.  That
would be possible but would involve extra complications (such as
keeping track of which segment size was used when HPTEs were inserted)
and is not addressed here.

Parts of this patch were originally written by Ben Herrenschmidt.

Signed-off-by: Paul Mackerras

[POWERPC] Fix performance monitor on machines with logical PVR

2007-10-11T11:37:50+00:00

Some IBM machines supply a "logical" PVR (processor version register)
value in the device tree in the cpu nodes rather than the real PVR.
This is used for instance to indicate that the processors in a POWER6
partition have been configured by the hypervisor to run in POWER5+
mode rather than POWER6 mode.  To cope with this, we call identify_cpu
a second time with the logical PVR value (the first call is with the
real PVR value in the very early setup code).

However, POWER5+ machines can also supply a logical PVR value, and use
the same value (the value that indicates a v2.04 architecture
compliant processor).  This causes problems for code that uses the
performance monitor (such as oprofile), because the PMU registers are
different in POWER6 (even in POWER5+ mode) from the real POWER5+.

This change works around this problem by taking out the PMU
information from the cputable entries for the logical PVR values, and
changing identify_cpu so that the second call to it won't overwrite
the PMU information that was established by the first call (the one
with the real PVR), but does update the other fields.  Specifically,
if the cputable entry for the logical PVR value has num_pmcs == 0,
none of the PMU-related fields get used.

So that we can create a mixed cputable entry, we now make cur_cpu_spec
point to a single static struct cpu_spec, and copy stuff from
cpu_specs[i] into it.  This has the side-effect that we can now make
cpu_specs[] be initdata.

Ultimately it would be good to move the PMU-related fields out to a
separate structure, pointed to by the cputable entries, and change
identify_cpu so that it saves the PMU info pointer, copies the whole
structure, and restores the PMU info pointer, rather than identify_cpu
having to list all the fields that are *not* PMU-related.

Signed-off-by: Paul Mackerras 
Acked-by: Benjamin Herrenschmidt

[POWERPC] mpc82xx: Define CPU_FTR_NEED_COHERENT

2007-10-04T16:02:21+00:00

The 8272 (and presumably other PCI PQ2 chips) appear to have the
same issue as the 83xx regarding PCI streaming DMA.

Signed-off-by: Scott Wood 
Signed-off-by: Kumar Gala

[POWERPC] Add cpu feature for SPE handling

2007-09-14T13:53:30+00:00

Make it so that SPE support can be determined at runtime.  This is similiar
to how we handle AltiVec.  This allows us to have SPE support built in and
work on processors with and without SPE.

Signed-off-by: Kumar Gala

[POWERPC] Consolidate PowerPC 750 cputable features

2007-07-10T11:55:50+00:00

The 750 CPU_FTR macros have quite a bit of duplication in them.  Consolidate
them to use CPU_FTRS_750 and only list the unique features for derivatives.

Signed-off-by: Josh Boyer 
Signed-off-by: Paul Mackerras

[POWERPC] Merge CPU features pertaining to icache coherency

2007-06-14T12:30:16+00:00

Currently the powerpc kernel has a 64-bit only feature,
COHERENT_ICACHE used for those CPUS which maintain icache/dcache
coherency in hardware (POWER5, essentially).  It also has a feature,
SPLIT_ID_CACHE, which is used on CPUs which have separate i and
d-caches, which is to say everything except 601 and Freescale E200.

In nearly all the places we check the SPLIT_ID_CACHE, what we actually
care about is whether the i and d-caches are coherent (which they will
be, trivially, if they're the same cache).

This tries to clarify the situation a little.  The COHERENT_ICACHE
feature becomes availble on 32-bit and is set for all CPUs where i and
d-cache are effectively coherent, whether this is due to special logic
(POWER5) or because they're unified.  We check this, instead of
SPLIT_ID_CACHE nearly everywhere.

The SPLIT_ID_CACHE feature itself is replaced by a UNIFIED_ID_CACHE
feature with reversed sense, set only on 601 and Freescale E200.  In
the two places (one Freescale BookE specific) where we really care
whether it's a unified cache, not whether they're coherent, we check
this feature.  The CPUs with unified cache are so few, we could
consider replacing this feature bit with explicit checks against the
PVR.

This will make unifying the 32-bit and 64-bit cache flush code a
little more straightforward.

Signed-off-by: David Gibson 
Signed-off-by: Paul Mackerras

[POWERPC] Remove CPU_FTR_NEED_COHERENT for 7448.

2007-05-17T11:10:15+00:00

Remove CPU_FTR_NEED_COHERENT for MPC7448 (and single-core MPC86xx).
This prevents needlessly setting M=1 when not SMP.

Signed-off-by: James.Yang 
Acked-by: Jon Loeliger 
Signed-off-by: Kumar Gala

[POWERPC] pasemi: PA6T oprofile support

2007-04-24T11:31:51+00:00

Oprofile support for PA6T, kernel side.

Also rename the PA6T_SPRN.* defines to SPRN_PA6T.*.

Signed-off-by: Olof Johansson 
Signed-off-by: Paul Mackerras