When a CPU is disabled via CPU hotplug, cpu_foreign_map is not updated.
This could result in cache management SMP calls being sent to offline
CPUs instead of online siblings in the same core.

Add a call to calculate_cpu_foreign_map() in the various MIPS cpu
disable callbacks after set_cpu_online(). All cases are updated for
consistency and to keep cpu_foreign_map strictly up to date, not just
those which may support hardware multithreading.

Fixes: cccf34e9 ("MIPS: c-r4k: Fix cache flushing for MT cores")
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Hongliang Tao <taohl@lemote.com>
Cc: Hua Yan <yanh@lemote.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13799/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The SMP flush_tlb_*() functions may clear the memory map's ASIDs for
other CPUs if the mm has only a single user (the current CPU) in order
to avoid SMP calls. However this makes it appear to has_valid_asid(),
which is used by various cache flush functions, as if the CPUs have
never run in the mm, and therefore can't have cached any of its memory.

For flush_tlb_mm() this doesn't sound unreasonable.

flush_tlb_range() corresponds to flush_cache_range() which does do full
indexed cache flushes, but only on the icache if the specified mapping
is executable, otherwise it doesn't guarantee that there are no cache
contents left for the mm.

flush_tlb_page() corresponds to flush_cache_page(), which will perform
address based cache ops on the specified page only, and also only
touches the icache if the page is executable. It does not guarantee that
there are no cache contents left for the mm.

For example, this affects flush_cache_range() which uses the
has_valid_asid() optimisation. It is required to flush the icache when
mappings are made executable (e.g. using mprotect) so they are
immediately usable. If some code is changed to non executable in order
to be modified then it will not be flushed from the icache during that
time, but the ASID on other CPUs may still be cleared for TLB flushing.
When the code is changed back to executable, flush_cache_range() will
assume the code hasn't run on those other CPUs due to the zero ASID, and
won't invalidate the icache on them.

This is fixed by clearing the other CPUs ASIDs to 1 instead of 0 for the
above two flush_tlb_*() functions when the corresponding cache flushes
are likely to be incomplete (non executable range flush, or any page
flush). This ASID appears valid to has_valid_asid(), but still triggers
ASID regeneration due to the upper ASID version bits being 0, which is
less than the minimum ASID version of 1 and so always treated as stale.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13795/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

MIPS64 needs to use compat_sys_keyctl for 32-bit userspace rather than
calling sys_keyctl.  The latter will work in a lot of cases, thereby hiding
the issue.
Reported-by: NStephan Mueller <smueller@chronox.de>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
cc: stable@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Cc: keyrings@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13832/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Currently the debugfs interface to print the segment configuration
refuses to print the physical address of mapped segments. However if the
EU bit is set these become unmapped at error level (when
CP0_Status.ERL=1), so the physical address is still relevant.

Update the logic to print the physical address of mapped segments when
the EU bit is set, while still hiding the Cache Coherency Attribute
(since EU overrides that to uncached when ERL=1 too).
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13833/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Introduce support for hotplug of Virtual Processors in MIPSr6 systems.
The method is simpler than the VPE parallel from the now-deprecated MT
ASE, it can now simply write the VP_STOP register with the mask of VPs
to halt, and use the VP_RUNNING register to determine when the VP has
halted.
Signed-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: NPaul Burton <paul.burton@imgtec.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13752/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The boot_core function was hardcoded to always start VP0 when starting
a core via the CPC. When hotplugging a CPU this may not be the desired
behaviour.

Make boot_core receive the VP ID to start running on the core, such that
alternate VPs can be started via CPU hotplug.
Also ensure that all other VPs within the core are stopped before
bringing the core out of reset so that only the desired VP starts.
Signed-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: NPaul Burton <paul.burton@imgtec.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13750/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

In microMIPS kernels, handle_signal() sets the isa16 mode bit in the
vdso address so that the sigreturn trampolines (which are offset from
the VDSO) get executed as microMIPS.

However commit ebb5e78c ("MIPS: Initial implementation of a VDSO")
changed the offsets to come from the VDSO image, which already have the
isa16 mode bit set correctly since they're extracted from the VDSO
shared library symbol table.

Drop the isa16 mode bit handling from handle_signal() to fix sigreturn
for cores which support both microMIPS and normal MIPS. This doesn't fix
microMIPS only cores, since the VDSO is still built for normal MIPS, but
thats a separate problem.

Fixes: ebb5e78c ("MIPS: Initial implementation of a VDSO")
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 4.4.x-
Patchwork: https://patchwork.linux-mips.org/patch/13348/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

As noticed by Sergei in the discussion of Andrea Gelmini's patch series.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Reported-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>

Signed-off-by: NAndrea Gelmini <andrea.gelmini@gelma.net>
Cc: paul.burton@imgtec.com
Cc: macro@imgtec.com
Cc: james.hogan@imgtec.com
Cc: jslaby@suse.cz
Cc: adam.buchbinder@gmail.com
Cc: trivial@kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13330/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NAndrea Gelmini <andrea.gelmini@gelma.net>
Cc: macro@imgtec.com
Cc: paul.burton@imgtec.com
Cc: Leonid.Yegoshin@imgtec.com
Cc: trivial@kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13329/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

When starting secondary VPEs which support EVA and the SegCtl registers,
copy the memory segmentation configuration from the running VPE to ensure
that all VPEs in the core have a consistent virtual memory map.

The EVA configuration of secondary cores is dealt with when starting the
core via the CM.
Signed-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13291/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Commit 12822570 ("MIPS: Separate XPA CPU feature into LPA and MVH")
wasn't fully applied, possibly due to a conflict with commit
f270d881 ("MIPS: Detect MIPSr6 Virtual Processor support"). This
left decode_config5() referring to the non-existent MIPS_CPU_XPA, which
breaks the build when XPA is enabled:

arch/mips/kernel/cpu-probe.c In function ‘decode_config5’:
arch/mips/kernel/cpu-probe.c:838:17: error: ‘MIPS_CPU_XPA’ undeclared (first use in this function)
   c->options |= MIPS_CPU_XPA;
                    ^

Apply the missing hunk, dropping the CONFIG_XPA ifdef and setting the
MIPS_CPU_MVH option when Config5.MVH is set.

Fixes: 12822570 ("MIPS: Separate XPA CPU feature into LPA and MVH")
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Link: https://patchwork.linux-mips.org/patch/13112/
Patchwork: https://patchwork.linux-mips.org/patch/13277/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

When using an external interrupt controller (EIC) the interrupt mask
bits in the cop0 Status register are reused for the Interrupt Priority
Level, and any interrupts with a priority lower than the field will be
ignored. Clear the field to 0 by default such that all interrupts are
serviced.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Reviewed-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Tested-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Cc: Qais Yousef <qsyousef@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13273/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

When using an external interrupt controller (EIC) the interrupt mask
bits in the cop0 Status register are reused for the Interrupt Priority
Level, and any interrupts with a priority lower than the field will be
ignored. Clear the field to 0 by default such that all interrupts are
serviced. Without doing so we default to arbitrarily ignoring all or
some subset of interrupts.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Reviewed-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Tested-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Cc: Joe Perches <joe@perches.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13272/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

most architectures are relying on mmap_sem for write in their
arch_setup_additional_pages.  If the waiting task gets killed by the oom
killer it would block oom_reaper from asynchronous address space reclaim
and reduce the chances of timely OOM resolving.  Wait for the lock in
the killable mode and return with EINTR if the task got killed while
waiting.
Signed-off-by: NMichal Hocko <mhocko@suse.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>	[x86 vdso]
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Define HAVE_EXIT_THREAD for archs which want to do something in
exit_thread. For others, let's define exit_thread as an empty inline.

This is a cleanup before we change the prototype of exit_thread to
accept a task parameter.

[akpm@linux-foundation.org: fix mips]
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: David Howells <dhowells@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix perf hardware performance counter event numbers for I6400. This core
does not follow the performance event numbering scheme of previous MIPS
cores. All performance counters (both odd and even) are capable of
counting any of the available events.

Fixes: 4e88a862 ("MIPS: Add cases for CPU_I6400")
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13259/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Fix a build regression from commit c9017757 ("MIPS: init upper 64b
of vector registers when MSA is first used"):

arch/mips/built-in.o: In function `enable_restore_fp_context':
traps.c:(.text+0xbb90): undefined reference to `_init_msa_upper'
traps.c:(.text+0xbb90): relocation truncated to fit: R_MIPS_26 against `_init_msa_upper'
traps.c:(.text+0xbef0): undefined reference to `_init_msa_upper'
traps.c:(.text+0xbef0): relocation truncated to fit: R_MIPS_26 against `_init_msa_upper'

to !CONFIG_CPU_HAS_MSA configurations with older GCC versions, which are
unable to figure out that calls to `_init_msa_upper' are indeed dead.
Of the many ways to tackle this failure choose the approach we have
already taken in `thread_msa_context_live'.

[ralf@linux-mips.org: Drop patch segment to junk file.]
Signed-off-by: NMaciej W. Rozycki <macro@imgtec.com>
Cc: stable@vger.kernel.org # v3.16+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13271/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

We will use it to count how many addresses are in the entry->ip[] array,
excluding PERF_CONTEXT_{KERNEL,USER,etc} entries, so that we can really
return the number of entries specified by the user via the relevant
sysctl, kernel.perf_event_max_contexts, or via the per event
perf_event_attr.sample_max_stack knob.

This way we keep the perf_sample->ip_callchain->nr meaning, that is the
number of entries, be it real addresses or PERF_CONTEXT_ entries, while
honouring the max_stack knobs, i.e. the end result will be max_stack
entries if we have at least that many entries in a given stack trace.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-s8teto51tdqvlfhefndtat9r@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

This makes perf_callchain_{user,kernel}() receive the max stack
as context for the perf_callchain_entry, instead of accessing
the global sysctl_perf_event_max_stack.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Zefan Li <lizefan@huawei.com>
Link: http://lkml.kernel.org/n/tip-kolmn1yo40p7jhswxwrc7rrd@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

If a kernel doesn't support MSA context (ie. CONFIG_CPU_HAS_MSA=n) then
it will only keep 64 bits per FP register in thread context, and the
calls to set_fpr64 in restore_msa_extcontext will overrun the end of the
FP register context into the FCSR & MSACSR values. GCC 6.x has become
smart enough to detect this & complain like so:

    arch/mips/kernel/signal.c: In function 'protected_restore_fp_context':
    ./arch/mips/include/asm/processor.h:114:17: error: array subscript is above array bounds [-Werror=array-bounds]
      fpr->val##width[FPR_IDX(width, idx)] = val;   \
      ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~
    ./arch/mips/include/asm/processor.h:118:1: note: in expansion of macro 'BUILD_FPR_ACCESS'
     BUILD_FPR_ACCESS(64)

The only way to trigger this code to run would be for a program to set
up an artificial extended MSA context structure following a sigframe &
execute sigreturn. Whilst this doesn't allow a program to write to any
state that it couldn't already, it makes little sense to allow this
"restoration" of MSA context in a system that doesn't support MSA.

Fix this by killing a program with SIGSYS if it tries something as crazy
as "restoring" fake MSA context in this way, also fixing the build error
& allowing for most of restore_msa_extcontext to be optimised out of
kernels without support for MSA.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Reported-by: NMichal Toman <michal.toman@imgtec.com>
Fixes: bf82cb30 ("MIPS: Save MSA extended context around signals")
Tested-by: NAaro Koskinen <aaro.koskinen@iki.fi>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Michal Toman <michal.toman@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: stable <stable@vger.kernel.org> # v4.3+
Patchwork: https://patchwork.linux-mips.org/patch/13164/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Calculate the MIPS clockevent device's min_delta_ns dynamically based on
the time it takes to perform the mips_next_event() sequence.

Virtualisation in particular makes the current fixed min_delta of 0x300
inappropriate under some circumstances, as the CP0_Count and CP0_Compare
registers may be being emulated by the hypervisor, and the frequency may
not correspond directly to the CPU frequency.

We actually use twice the median of multiple 75th percentiles of
multiple measurements of how long the mips_next_event() sequence takes,
in order to fairly efficiently eliminate outliers due to unexpected
hypervisor latency (which would need handling with retries when it
occurs during normal operation anyway).
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13176/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Commit 9791554b ("MIPS,prctl: add PR_[GS]ET_FP_MODE prctl options
for MIPS") added support for the PR_SET_FP_MODE prctl, which allows a
userland program to modify its FP mode at runtime. This is most notably
required if dynamic linking leads to the FP mode requirement changing at
runtime from that indicated in the initial executable's ELF header. In
order to avoid overhead in the general FP context restore code, it aimed
to have threads in the process become unable to enable the FPU during a
mode switch & have the thread calling the prctl syscall wait for all
other threads in the process to be context switched at least once. Once
that happens we can know that no thread in the process whose mode will
be switched has live FP context, and it's safe to perform the mode
switch. However in the (rare) case of modeswitches occurring in
multithreaded programs this can lead to indeterminate delays for the
thread invoking the prctl syscall, and the code monitoring for those
context switches was woefully inadequate for all but the simplest cases.

Fix this by broadcasting an IPI if other CPUs may have live FP context
for an affected thread, with a handler causing those CPUs to relinquish
their FPU ownership. Threads will then be allowed to continue running
but will stall on the wait_on_atomic_t in enable_restore_fp_context if
they attempt to use FP again whilst the mode switch is still in
progress. The end result is less fragile poking at scheduler context
switch counts & a more expedient completion of the mode switch.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Fixes: 9791554b ("MIPS,prctl: add PR_[GS]ET_FP_MODE prctl options for MIPS")
Reviewed-by: NMaciej W. Rozycki <macro@imgtec.com>
Cc: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: stable <stable@vger.kernel.org> # v4.0+
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13145/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Whilst a PR_SET_FP_MODE prctl is performed there are decisions made
based upon whether the task is executing on the current CPU. This may
change if we're preempted, so disable preemption to avoid such changes
for the lifetime of the mode switch.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Fixes: 9791554b ("MIPS,prctl: add PR_[GS]ET_FP_MODE prctl options for MIPS")
Reviewed-by: NMaciej W. Rozycki <macro@imgtec.com>
Tested-by: NAurelien Jarno <aurelien@aurel32.net>
Cc: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: stable <stable@vger.kernel.org> # v4.0+
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13144/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

If an address error exception occurs for a LDXC1 or SDXC1 instruction,
within the cop1x opcode space, allow it to be passed through to the FPU
emulator rather than resulting in a SIGILL. This causes LDXC1 & SDXC1 to
be handled in a manner consistent with the more common LDC1 & SDC1
instructions.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Tested-by: NAurelien Jarno <aurelien@aurel32.net>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13143/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Correct the cases missed with commit 9b26616c ("MIPS: Respect the
ISA level in FCSR handling") and prevent writes to read-only FCSR bits
there.

This in particular applies to FP context initialisation where any IEEE
754-2008 bits preset by `mips_set_personality_nan' are cleared before
the relevant ptrace(2) call takes effect and the PTRACE_POKEUSR request
addressing FPC_CSR where no masking of read-only FCSR bits is done.

Remove the FCSR clearing from FP context initialisation then and unify
PTRACE_POKEUSR/FPC_CSR and PTRACE_SETFPREGS handling, by factoring out
code from `ptrace_setfpregs' and calling it from both places.

This mostly matters to soft float configurations where the emulator can
be switched this way to a mode which should not be accessible and cannot
be set with the CTC1 instruction.  With hard float configurations any
effect is transient anyway as read-only bits will retain their values at
the time the FP context is restored.
Signed-off-by: NMaciej W. Rozycki <macro@imgtec.com>
Cc: stable@vger.kernel.org # v4.0+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13239/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Fix a floating-point context restoration regression introduced with
commit 9b26616c ("MIPS: Respect the ISA level in FCSR handling")
that causes a Floating Point exception and consequently a kernel oops
with hard float configurations when one or more FCSR Enable and their
corresponding Cause bits are set both at a time via a ptrace(2) call.

To do so reinstate Cause bit masking originally introduced with commit
b1442d39 ("MIPS: Prevent user from setting FCSR cause bits") to
address this exact problem and then inadvertently removed from the
PTRACE_SETFPREGS request with the commit referred above.
Signed-off-by: NMaciej W. Rozycki <macro@imgtec.com>
Cc: stable@vger.kernel.org # v4.0+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13238/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Remove a duplicate o32 `elf_check_arch' implementation, move all macro
variants to <asm/elf.h> and define them unconditionally under indvidual
names, substituting alias `elf_check_arch' definitions in variant code.
Signed-off-by: NMaciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13245/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NMaciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13244/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Add a few new cpu-features.h definitions for VZ sub-features, namely the
existence of the CP0_GuestCtl0Ext, CP0_GuestCtl1, and CP0_GuestCtl2
registers, and support for GuestID to dialias TLB entries belonging to
different guests.

Also add certain features present in the guest, with the naming scheme
cpu_guest_has_*. These are added separately to the main options bitfield
since they generally parallel similar features in the root context. A
few of these (FPU, MSA, watchpoints, perf counters, CP0_[X]ContextConfig
registers, MAAR registers, and probably others in future) can be
dynamically configured in the guest context, for which the
cpu_guest_has_dyn_* macros are added.

[ralf@linux-mips.org: Resolve merge conflict.]
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13231/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The decode_config4() function reads kscratch_mask from
CP0_Config4.KScrExist using a hard coded shift and mask. We already have
a definition for the mask in mipsregs.h, so add a definition for the
shift and make use of them.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13227/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Add CPU feature for standard MIPS r2 performance counters, as determined
by the Config1.PC bit. Both perf_events and oprofile probe this bit, so
lets combine the probing and change both to use cpu_has_perf.

This will also be used for VZ support in KVM to know whether performance
counters exist which can be exposed to guests.

[ralf@linux-mips.org: resolve conflict.]
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Robert Richter <rric@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: oprofile-list@lists.sf.net
Patchwork: https://patchwork.linux-mips.org/patch/13226/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The CP0_[X]ContextConfig registers are present if CP0_Config3.CTXTC or
CP0_Config3.SM are set, and provide more control over which bits of
CP0_[X]Context are set to the faulting virtual address on a TLB
exception.

KVM/VZ will need to be able to save and restore these registers in the
guest context, so add the relevant definitions and probing of the
ContextConfig feature in the root context first.

[ralf@linux-mips.org: resolve merge conflict.]
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13225/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The optional CP0_BadInstr and CP0_BadInstrP registers are written with
the encoding of the instruction that caused a synchronous exception to
occur, and the prior branch instruction if in a delay slot.

These will be useful for instruction emulation in KVM, and especially
for VZ support where reading guest virtual memory is a bit more awkward.

Add CPU option numbers and cpu_has_* definitions to indicate the
presence of each registers, and add code to probe for them using bits in
the CP0_Config3 register.

[ralf@linux-mips.org: resolve merge conflict.]
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13224/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The CP0_EBase register may optionally have a write gate (WG) bit to
allow the upper bits to be written, i.e. bits 31:30 on MIPS32 since r3
(to allow for an exception base outside of KSeg0/KSeg1 when segmentation
control is in use) and bits 63:30 on MIPS64 (which also implies the
extension of CP0_EBase to 64 bits long).

The presence of this feature will need to be known about for VZ support
in order to correctly save and restore all the bits of the guest
CP0_EBase register, so add CPU feature definition and probing for this
feature.

Probing the WG bit on MIPS64 can be a bit fiddly, since 64-bit COP0
register access instructions were UNDEFINED for 32-bit registers prior
to MIPS r6, and it'd be nice to be able to probe without clobbering the
existing state, so there are 3 potential paths:

- If we do a 32-bit read of CP0_EBase and the WG bit is already set, the
  register must be 64-bit.

- On MIPS r6 we can do a 64-bit read-modify-write to set CP0_EBase.WG,
  since the upper bits will read 0 and be ignored on write if the
  register is 32-bit.

- On pre-r6 cores, we do a 32-bit read-modify-write of CP0_EBase. This
  avoids the potentially UNDEFINED behaviour, but will clobber the upper
  32-bits of CP0_EBase if it isn't a simple sign extension (which also
  requires us to ensure BEV=1 or modifying the exception base would be
  UNDEFINED too). It is hopefully unlikely a bootloader would set up
  CP0_EBase to a 64-bit segment and leave WG=0.

[ralf@linux-mips.org: Resolved merge conflict.]
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Tested-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13223/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Octeon machines support running in little endian mode. U-Boot usually
runs in big endian-mode. Therefore the initramfs is loaded in big endian
mode, and the kernel later tries to access it in little endian mode.

This patch fixes that by detecting byte swapped initramfs using either the
CPIO header or the header from standard compression methods, and
byte swaps it if needed. It first checks that the header doesn't match
in the native endianness to avoid false detections. It uses the kernel
decompress library so that we don't have to maintain the list of magics
if some decompression methods are added to the kernel.
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>
Acked-by: NDavid Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13219/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Make BMIPS4380 and BMIPS5000 advertise support for RIXI through
cpu_probe_broadcom(). bmips_cpu_setup() needs to be called shortly after that,
during prom_init() in order to enable the proper Broadcom-specific register to
turn on RIXI and the "rotr" instruction.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Cc: john@phrozen.org
Cc: cernekee@gmail.com
Cc: jon.fraser@broadcom.com
Cc: pgynther@google.com
Cc: paul.burton@imgtec.com
Cc: ddaney.cavm@gmail.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12507/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Some processors may not have the RIXI bit advertised in the Config3 register,
not being a MIPS32R2 or R6 core, yet, they might be supporting it through a
different way, which is overriden during vendor-specific cpu_probe().

Move the RIXI exceptions enabling after the vendor-specific cpu_probe()
function has had a change to run and override the current CPU's options with
MIPS_CPU_RIXI.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Cc: john@phrozen.org
Cc: cernekee@gmail.com
Cc: jon.fraser@broadcom.com
Cc: pgynther@google.com
Cc: paul.burton@imgtec.com
Cc: ddaney.cavm@gmail.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12506/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

asm/pgtable-bits.h is included in 2 assembly files and thus has to
ifdef around C code, however nothing defined by the header is used
in either of the assembly files that include it.

Remove the redundant inclusions such that asm/pgtable-bits.h doesn't
need to #ifdef around C code, for cleanliness and in preparation for
later patches which will add more C.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Reviewed-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Jonas Gorski <jogo@openwrt.org>
Cc: Alex Smith <alex.smith@imgtec.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13114/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

XPA (eXtended Physical Addressing) should be detected as a combination
of two architectural features:
- Large Physical Address (as per Config3.LPA). With XPA this will be set
  on MIPS32r5 cores, but it may also be set for MIPS64r2 cores too.
- MTHC0/MFHC0 instructions (as per Config5.MVH). With XPA this will be
  set, but it may also be set in VZ guest context even when Config3.LPA
  in the guest context has been cleared by the hypervisor.

As such, XPA is only usable if both bits are set. Update CPU features to
separate these two features, with cpu_has_xpa requiring both to be set.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: Joshua Kinard <kumba@gentoo.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13112/Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>