The caches enabled case needs more work, but is presently broken
regardless, so this can be done incrementally.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This is superfluous, as the default CPU type and family are already
established by the initial cpuinfo definition. Given that we are still
able to probe for the CPU family even if we are not able to detect the
subtype, it's preferable to let the probing code fill out what it can and
leave the rest.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This paves the way for allowing individual CPUs to overload the
individual flushing routines that they care about without having to
depend on weak aliases. SH-4 is converted over initially, as it wires
up pretty much everything. The majority of the other CPUs will simply use
the default no-op implementation with their own region flushers wired up.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

We use flush_cache_page() outright in copy_to_user_page(), and nothing
else needs it, so just kill it off. SH-5 still defines its own version,
but that too will go away in the same fashion once it converts over.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

All of the flush_dcache_mmap_lock()/flush_dcache_mmap_unlock()
definitions are identical across all CPUs, so just provide them
generically in asm/cacheflush.h.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

flush_dcache_all() is used internally by the SH-4 cache code, it is not
part of the exported cache API, so make it static and don't export it.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This migrates the alias computation and printing of probed cache
parameters from the SH-4 code to the shared cpu_cache_init().

This permits other platforms with aliases to make use of the same
probe logic without having to roll their own, and also produces
consistent output regardless of platform.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This provides a central point for CPU cache initialization routines.
This replaces the antiquated p3_cache_init() method, which the vast
majority of CPUs never cared about.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This adds a family member to struct sh_cpuinfo, which allows us to fall
back more on the probe routines to work out what sort of subtype we are
running on. This will be used by the CPU cache initialization code in
order to first do family-level initialization, followed by subtype-level
optimizations.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

These were previous littered around tlb-nommu.c and pg-nommu.c, though at
this point there are more stubs than are strictly TLB or page op related,
so just consolidate them in a single nommu.c.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This does a bit of reorganizing for allowing nommu to use the new
and generic cache.c, no functional changes.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This builds in the newly created cache.c (renamed from pg-mmu.c) for both
MMU and NOMMU configurations. The kmap_coherent() stubs and alias
information recorded by each CPU family takes care of doing the right
thing while enabling the code to be commonly shared.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This plugs in kmap_coherent() for the non-SH4 cases to permit the
pg-mmu.c bits to be used generically across all CPUs. SH-5 is still in
the TODO state, but will move over to fixmap and the generic interface
gradually.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This kills off the ifdef from kmap_coherent_init() and just bails if
there are no cache aliases. This permits the kmap coherent code to be
used on other CPUs.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This only bothers with the TLB entry flush in the case of the initial
page write exception, as it is unecessary in the case of the load/store
exceptions.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This adds a bit of rework to have the TLB protection violations skip the
TLB miss fastpath and go directly in to do_page_fault(), as these require
slow path handling.

Based on an earlier patch by SUGIOKA Toshinobu.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This optimizes for the cases when a CPU does not yet have a valid ASID
context associated with it, as in this case there is no work for any of
flush_cache_mm()/flush_cache_page()/flush_cache_range() to do. Based on
the the MIPS implementation.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Now with all of the prep work out of the way, kill off the SH-5 variants
and use the SH-4 version directly. This also takes advantage of the
unrolling that was previously done for the new version.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This plugs in some register alignment helpers for the shared flushers,
allowing them to also be used on SH-5. The main rationale here is that
in the SH-5 case we have a variable ABI, where the pointer size may not
equal the register width. This register extension is taken care of by
the SH-5 code already today, and is otherwise unused on the SH-4 code.
This combines the two and allows us to kill off the SH-5 implementation.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This inserts a ULONG_MAX entry at the end of the valid entries in the
stack trace buffer so the default code doesn't need to scan to the end of
available slots. This also makes the trace buffer termination behaviour
consistent with the other architectures.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This flags the default unwinder as reliable, as it tends to be reliable
enough for the purposes of the stacktrace buffer. We leave the unreliable
cases for the unwind methods that we know to be completely broken.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This adopts the reliability checks from the x86 stacktrace code so known
bad addresses are not recorded in the stack trace buffer.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

save_stack_trace_tsk() and friends can be called from atomic context (as
triggered by latencytop), and subsequently hit two problematic allocation
points that were using GFP_KERNEL (these were dwarf_unwind_stack() and
dwarf_frame_alloc_regs()). Convert these over to GFP_ATOMIC and get
latencytop working with the DWARF unwinder.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Trying to figure out the best value for DWARF_ARCH_UNWIND_OFFSET is
tricky at best. Various things can change the size (and offset from the
beginning of the function) of the prologue. Notably, turning on ftrace
adds calls to mcount at the beginning of functions, thereby pushing the
prologue further into the function.

So replace DWARF_ARCH_UNWIND_OFFSET with some code that continues to
execute CFA instructions until the value of return address register is
defined. This is safe to do because we know that the return address must
have been pushed onto the frame before our first function call; we just
can't figure out where at compile-time.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This is no longer used, kill it off.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

The destination address might be unaligned, so set it with
put_unaligned() for safety. This restores the previous behaviour, albeit
through the proper API.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This was using internal symbols for unaligned accesses, bypassing the
exposed interface for variable sized safe accesses. This converts all of
the __get_unaligned_cpuXX() users over to get_unaligned() directly,
relying on the cast to select the proper internal routine.

Additionally, the __put_unaligned_cpuXX() case is superfluous given that
the destination address is aligned in all of the current cases, so just
drop that outright.

Furthermore, this switches to the asm/unaligned.h header instead of the
asm-generic version, which was silently bypassing the SH-4A optimized
unaligned ops.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Annotate various assembly code paths with CFI assembler directives so
that DWARF unwind info is available for the unwinder.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

In order to use DWARF unwinder info the frame register has to contain a
valid value. Whilst GCC takes care of this for C code, we have to do it
ourselves for assembly.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This is a first cut at a generic DWARF unwinder for the kernel. It's
still lacking DWARF64 support and the DWARF expression support hasn't
been tested very well but it is generating proper stacktraces on SH for
WARN_ON() and NULL dereferences.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Instead of implementing our own stack unwinder via dump_trace() we
should use the new stack unwinder API because it is more modular. This
change allows us to decouple the interface for generating stacktraces
from the implementation of a stack unwinder.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Provide an interface for registering stack unwinders, where each
unwinder is given a rating that describes its accuracy and
complexity. The more accurate an unwinder is, the more complex it is.

If a the current stack unwinder faults, then the stack unwinder with the
next highest accuracy will be used in its place (provided one is
available). For example, this allows unwinders, such as the DWARF
unwinder, to liberally sprinkle BUG()s to catch badly formed DWARF debug
info.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Copy the stacktrace ops code from x86 and provide a central function for
use by functions that need to dump a callstack.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: linux-sh@vger.kernel.org
Signed-off-by: Paul Mundt <lethal@linux-sh.org>