This and the next patch resolve memory corruption problems while CPU
hotplug. Without these patches, memory corruption can triggered easily
as below:

On a quad-core MIPS platform, use "spawn" of UnixBench-5.1.3 (http://
code.google.com/p/byte-unixbench/) and a CPU hotplug script like this
(hotplug.sh):
while true; do
echo 0 >/sys/devices/system/cpu/cpu1/online
echo 0 >/sys/devices/system/cpu/cpu2/online
echo 0 >/sys/devices/system/cpu/cpu3/online
sleep 1
echo 1 >/sys/devices/system/cpu/cpu1/online
echo 1 >/sys/devices/system/cpu/cpu2/online
echo 1 >/sys/devices/system/cpu/cpu3/online
sleep 1
done

Run "hotplug.sh" and then run "spawn 10000", spawn will get segfault
after a few minutes.

This patch:
Currently, clear_page()/copy_page() are generated by Micro-assembler
dynamically. But they are unavailable until uasm_resolve_relocs() has
finished because jump labels are illegal before that. Since these
functions are shared by every CPU, we only call build_clear_page()/
build_copy_page() only once at boot time. Without this patch, programs
will get random memory corruption (segmentation fault, bus error, etc.)
while CPU Hotplug (e.g. one CPU is using clear_page() while another is
generating it in cpu_cache_init()).

For similar reasons we modify build_tlb_refill_handler()'s invocation.

V2:
1, Rework the code to make CPU#0 can be online/offline.
2, Introduce cpu_has_local_ebase feature since some types of MIPS CPU
   need a per-CPU tlb_refill_handler().
Signed-off-by: NHuacai Chen <chenhc@lemote.com>
Signed-off-by: NHongbing Hu <huhb@lemote.com>
Acked-by: NDavid Daney <david.daney@cavium.com>
Patchwork: http://patchwork.linux-mips.org/patch/4994/Acked-by: NJohn Crispin <blogic@openwrt.org>

The presence of the MIPS Virtualization Application-Specific Extension
is indicated by CP0_Config3[23].  Probe for this and report it in
/proc/cpuinfo.
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Patchwork: http://patchwork.linux-mips.org/patch/4904/Signed-off-by: NJohn Crispin <blogic@openwrt.org>

Signed-off-by: NSteven J. Hill <sjhill@mips.com>
Patchwork: http://patchwork.linux-mips.org/patch/4682/Signed-off-by: NJohn Crispin <blogic@openwrt.org>

Display the MIPS ISA version release in the /proc/cpuinfo file.

[ralf@linux-mips.org: Add support for MIPS I ... IV legacy architecture
revisions.  Also differenciate between MIPS32 and MIPS64 versions instead
of lumping them together as just r1 and r2.

Note to application programmers: this indicates the CPU's ISA level
It does not imply the current execution environment does support it.  For
example an O32 application seeing "mips64r2" would still be restricted by
by the execution environment to 32-bit - but the kernel could run mips64r2
code.  The same for a 32-bit kernel running on a 64-bit processor.  This
field doesn't include ASEs or optional architecture modules nor other
detailed flags such as the availability of an FPU.]
Signed-off-by: NSteven J. Hill <sjhill@mips.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/4714/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Having received another series of whitespace patches I decided to do this
once and for all rather than dealing with this kind of patches trickling
in forever.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

[ralf@linux-mips.org: This patch really only detects the ASE and passes its
existence on to userland via /proc/cpuinfo.  The DSP ASE Rev 2. adds new
resources but no resources that would need management by the kernel.]
Signed-off-by: NSteven J. Hill <sjhill@mips.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/4165/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The PCI (Program Counter Interrupt) bit in the "cause" register
is mandatory for MIPS32R2 cores, but has also been added to some R1
cores (BMIPS5000). This change adds a cpu feature bit to make it
easier to check for and use this feature.
Signed-off-by: NAl Cooper <alcooperx@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/4106/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Remove usage of the 'kernel_uses_smartmips_rixi' macro from all files
and use new 'cpu_has_rixi' instead.
Signed-off-by: NSteven J. Hill <sjhill@mips.com>
Acked-by: NDavid Daney <david.daney@cavium.com>

Originally both Read Inhibit (RI) and Execute Inhibit (XI) were
supported by the TLB only for a SmartMIPS core. The MIPSr3(TM)
Architecture now defines an optional feature to implement these
TLB bits separately. Support for one or both features can be
checked by looking at the Config3.RXI bit.
Signed-off-by: NSteven J. Hill <sjhill@mips.com>
Acked-by: NDavid Daney <david.daney@cavium.com>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The SmartMIPS ASE specifies how Read Inhibit (RI) and eXecute Inhibit
(XI) bits in the page tables work.  The upper two bits of EntryLo{0,1}
are RI and XI when the feature is enabled in the PageGrain register.
SmartMIPS only covers 32-bit systems.  Cavium Octeon+ extends this to
64-bit systems by continuing to place the RI and XI bits in the top of
EntryLo even when EntryLo is 64-bits wide.

Because we need to carry the RI and XI bits in the PTE, the layout of
the PTE is changed.  There is a two instruction overhead in the TLB
refill hot path to get the EntryLo bits into the proper position.
Also the TLB load exception has to probe the TLB to check if RI or XI
caused the exception.

Also of note is that the layout of the PTE bits is done at compile and
runtime rather than statically.  In the 32-bit case this allows for
the same number of PFN bits as before the patch as the _PAGE_HUGE is
not supported in 32-bit kernels (we have _PAGE_NO_EXEC and
_PAGE_NO_READ instead of _PAGE_READ and _PAGE_HUGE).

The patch is tested on Cavium Octeon+, but should also work on 32-bit
systems with the Smart-MIPS ASE.
Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/952/
Patchwork: http://patchwork.linux-mips.org/patch/956/
Patchwork: http://patchwork.linux-mips.org/patch/962/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Linux kernel 2.6.32 and later allocate address space from the top of the
kernel virtual memory address space.

This patch implements virtual memory size detection for 64 bit MIPS CPUs
to avoid resulting crashes.
Signed-off-by: NGuenter Roeck <guenter.roeck@ericsson.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/935/Reviewed-by: NDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

On some CPUs, it is more efficient to disable and enable interrupts in the
kernel rather than use ll/sc for atomic operations.  But if we were to set
cpu_has_llsc to false, we would break the userspace futex interface (in
asm/futex.h).

We separate the two concepts, with a new predicate kernel_uses_llsc, that
lets us disable the kernel's use of ll/sc while still allowing the futex
code to use it.

Also there were a couple of cases in bitops.h where we were using ll/sc
unconditionally even if cpu_has_llsc were false.
Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Some CPUs have implementation dependent rdhwr registers.  Allow them
to be enabled on a per CPU basis.
Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Some CPUs do not need ehb instructions after writing CP0 registers.
By allowing ehb generation to be overridden in
cpu-feature-overrides.h, we can save a few instructions in the TLB
handler hot paths.
Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This is useful for IDT RC32332, RC32334 and NEC VR5500 processors which do
not implement the full MIPS32 / MIPS64 architecture.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Follow precedent of other boards, and hook-up the CPU specific cache
init.
Signed-off-by: NTomaso Paoletti <tpaoletti@caviumnetworks.com>
Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

cpu_has_mips_r is true if a processor is MIPS32 or MIPS64, any architecture
revision.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Freeing prom memory: 956kb freed
Freeing firmware memory: 978944k freed
Freeing unused kernel memory: 180k freed
BUG: using smp_processor_id() in preemptible [00000000] code: swapper/1
caller is r4k_dma_cache_wback_inv+0x144/0x2a0
Call Trace:
 [<80117af8>] r4k_dma_cache_wback_inv+0x144/0x2a0
 [<802e4b84>] debug_smp_processor_id+0xd4/0xf0
 [<802e4b7c>] debug_smp_processor_id+0xcc/0xf0
...
CONFIG_DEBUG_PREEMPT is enabled.
--
Bug cause is blast_dcache_range() in preemptible code [in
r4k_dma_cache_wback_inv()].
blast_dcache_range() is constructed via __BUILD_BLAST_CACHE_RANGE that
uses cpu_dcache_line_size(). It uses current_cpu_data that use
smp_processor_id() in turn. In case of CONFIG_DEBUG_PREEMPT
smp_processor_id emits BUG if we are executing with preemption
enabled.

Cpu options of cpu0 are assumed to be the superset of all processors.

Can I make the same assumptions for cache line size  and fix this
issue the following way:
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This saves a few k on systems which only ever ship with a single CPU type.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

It may not be perfect yet but the SB1 code is badly borken and has
horrible performance issues.

Downside: This seriously breaks support for pass 1 parts of the BCM1250
where indexed cacheops don't work quite reliable but I seem to be the
last one on the planet with a pass 1 part anyway.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Which will cut down the cost of RDHWR $29 which is used to obtain the
TLS pointer and so far being emulated in software down to a single cycle
operation.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NChris Dearman <chris@mips.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

    
If dcache_size != icache_size or dcache_size != scache_size, or
set-associative cache, icache/scache does not flushed properly.  Make
blast_?cache_page_indexed() masks its index value correctly.  Also,
use physical address for physically indexed pcache/scache.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@ongar.mips.com>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

options and the precense of the MT ASE.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

causing some headache for debuggers knowing about signal frames.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Start cleaning 32-bit vs. 64-bit configuration.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

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!