On uniprocessor, it's always zero for optimize that.

On SMP, the jmpl to the stub kills the return address stack in the cpu
branch prediction logic, so expand the code sequence inline and use a
code patching section to fix things up.  This also always better and
explicit register selection, which will be taken advantage of in a
future changeset.

The hard_smp_processor_id() function is big, so do not inline it.

Fix up tests for Jalapeno to also test for Serrano chips too.  These
tests want "jbus Ultra-IIIi" cases to match, so that is what we should
test for.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The are distrupting, which by the sparc v9 definition means they
can only occur when interrupts are enabled in the %pstate register.
This never occurs in any of the trap handling code running at
trap levels > 0.

So just mark it as an unexpected trap.

This allows us to kill off the cee_stuff member of struct thread_info.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

UltraSPARC has special sets of global registers which are switched to
for certain trap types.  There is one set for MMU related traps, one
set of Interrupt Vector processing, and another set (called the
Alternate globals) for all other trap types.

For what seems like forever we've hard coded the values in some of
these trap registers.  Some examples include:

1) Interrupt Vector global %g6 holds current processors interrupt
   work struct where received interrupts are managed for IRQ handler
   dispatch.

2) MMU global %g7 holds the base of the page tables of the currently
   active address space.

3) Alternate global %g6 held the current_thread_info() value.

Such hardcoding has resulted in some serious issues in many areas.
There are some code sequences where having another register available
would help clean up the implementation.  Taking traps such as
cross-calls from the OBP firmware requires some trick code sequences
wherein we have to save away and restore all of the special sets of
global registers when we enter/exit OBP.

We were also using the IMMU TSB register on SMP to hold the per-cpu
area base address, which doesn't work any longer now that we actually
use the TSB facility of the cpu.

The implementation is pretty straight forward.  One tricky bit is
getting the current processor ID as that is different on different cpu
variants.  We use a stub with a fancy calling convention which we
patch at boot time.  The calling convention is that the stub is
branched to and the (PC - 4) to return to is in register %g1.  The cpu
number is left in %g6.  This stub can be invoked by using the
__GET_CPUID macro.

We use an array of per-cpu trap state to store the current thread and
physical address of the current address space's page tables.  The
TRAP_LOAD_THREAD_REG loads %g6 with the current thread from this
table, it uses __GET_CPUID and also clobbers %g1.

TRAP_LOAD_IRQ_WORK is used by the interrupt vector processing to load
the current processor's IRQ software state into %g6.  It also uses
__GET_CPUID and clobbers %g1.

Finally, TRAP_LOAD_PGD_PHYS loads the physical address base of the
current address space's page tables into %g7, it clobbers %g1 and uses
__GET_CPUID.

Many refinements are possible, as well as some tuning, with this stuff
in place.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Delete all of the code working with sp_banks[] and replace
with clean acquisition and sorting of physical memory
parameters from the firmware.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Need to make sure the address is below high_memory before
passing it to kern_addr_valid().
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Thus, we can mark sp_banks[] static in arch/sparc64/mm/init.c
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The funny "range" exception table entries we had were only
used by the compat layer socketcall assembly, and it wasn't
even needed there.

For free we now get proper exception table sorting and fast
binary searching.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

At boot time, determine the D-cache, I-cache and E-cache size and
line-size.  Use them in cache flushes when appropriate.

This change was motivated by discovering that the D-cache on
UltraSparc-IIIi and later are 64K not 32K, and the flushes done by the
Cheetah error handlers were assuming a 32K size.

There are still some pieces of code that are hard coding things and
will need to be fixed up at some point.

While we're here, fix the D-cache and I-cache parity error handlers
to run with interrupts disabled, and when the trap occurs at trap
level > 1 log the event via a counter displayed in /proc/cpuinfo.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Current uncorrectable error handling was poor enough
that the processor could just loop taking the same
trap over and over again.  Fix things up so that we
at least get a log message and perhaps even some register
state.

In the process, much consolidation became possible,
particularly with the correctable error handler.

Prefix assembler and C function names with "spitfire"
to indicate that these are for Ultra-I/II/IIi/IIe only.

More work is needed to make these routines robust and
featureful to the level of the Ultra-III error handlers.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Verify we really are taking a data access exception trap, at TL1, from
one of the window spill/fill handlers.

Else call a new function, data_access_exception_tl1, to log the error.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

GCC 4.x really dislikes the games we are playing in
unaligned.c, and the cleanest way to fix this is to
move things into assembler.

Noted by Al Viro.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

These two bits were accesses non-atomically from assembler
code.  So, in order to eliminate any potential races resulting
from that, move these pieces of state into two bytes elsewhere
in struct thread_info.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Older UltraSPARC-III chips have a P-Cache bug that makes us disable it
by default at boot time.

However, this does hurt performance substantially, particularly with
memcpy(), and the bug is _incredibly_ obscure.  I have never seen it
triggered in practice, ever.

So provide a "-P" boot option that forces the P-Cache on.  It taints
the kernel, so if it does trigger and cause some data corruption or
OOPS, we will find out in the logs that this option was on when it
happened.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!