Use 64-bit accesses for 64-bit floating-point general registers with
PTRACE_PEEKUSR, removing the truncation of their upper halves in the
FR=1 mode, caused by commit bbd426f5 ("MIPS: Simplify FP context
access"), which inadvertently switched them to using 32-bit accesses.

The PTRACE_POKEUSR side is fine as it's never been broken and continues
using 64-bit accesses.

Fixes: bbd426f5 ("MIPS: Simplify FP context access")
Signed-off-by: NMaciej W. Rozycki <macro@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 3.15+
Patchwork: https://patchwork.linux-mips.org/patch/19334/Signed-off-by: NJames Hogan <jhogan@kernel.org>

Having PR_FP_MODE_FRE (i.e. Config5.FRE) set without PR_FP_MODE_FR (i.e.
Status.FR) is not supported as the lone purpose of Config5.FRE is to
emulate Status.FR=0 handling on FPU hardware that has Status.FR=1
hardwired[1][2].  Also we do not handle this case elsewhere, and assume
throughout our code that TIF_HYBRID_FPREGS and TIF_32BIT_FPREGS cannot
be set both at once for a task, leading to inconsistent behaviour if
this does happen.

Return unsuccessfully then from prctl(2) PR_SET_FP_MODE calls requesting
PR_FP_MODE_FRE to be set with PR_FP_MODE_FR clear.  This corresponds to
modes allowed by `mips_set_personality_fp'.

References:

[1] "MIPS Architecture For Programmers, Vol. III: MIPS32 / microMIPS32
    Privileged Resource Architecture", Imagination Technologies,
    Document Number: MD00090, Revision 6.02, July 10, 2015, Table 9.69
    "Config5 Register Field Descriptions", p. 262

[2] "MIPS Architecture For Programmers, Volume III: MIPS64 / microMIPS64
    Privileged Resource Architecture", Imagination Technologies,
    Document Number: MD00091, Revision 6.03, December 22, 2015, Table
    9.72 "Config5 Register Field Descriptions", p. 288

Fixes: 9791554b ("MIPS,prctl: add PR_[GS]ET_FP_MODE prctl options for MIPS")
Signed-off-by: NMaciej W. Rozycki <macro@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 4.0+
Patchwork: https://patchwork.linux-mips.org/patch/19327/Signed-off-by: NJames Hogan <jhogan@kernel.org>

Check the TIF_32BIT_FPREGS task setting of the tracee rather than the
tracer in determining the layout of floating-point general registers in
the floating-point context, correcting access to odd-numbered registers
for o32 tracees where the setting disagrees between the two processes.

Fixes: 597ce172 ("MIPS: Support for 64-bit FP with O32 binaries")
Signed-off-by: NMaciej W. Rozycki <macro@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 3.14+
Signed-off-by: NJames Hogan <jhogan@kernel.org>

Correct commit 7aeb753b ("MIPS: Implement task_user_regset_view.")
and expose the FIR register using the unused 4 bytes at the end of the
NT_PRFPREG regset.  Without that register included clients cannot use
the PTRACE_GETREGSET request to retrieve the complete FPU register set
and have to resort to one of the older interfaces, either PTRACE_PEEKUSR
or PTRACE_GETFPREGS, to retrieve the missing piece of data.  Also the
register is irreversibly missing from core dumps.

This register is architecturally hardwired and read-only so the write
path does not matter.  Ignore data supplied on writes then.

Fixes: 7aeb753b ("MIPS: Implement task_user_regset_view.")
Signed-off-by: NJames Hogan <jhogan@kernel.org>
Signed-off-by: NMaciej W. Rozycki <macro@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 3.13+
Patchwork: https://patchwork.linux-mips.org/patch/19273/Signed-off-by: NJames Hogan <jhogan@kernel.org>

Using this helper allows us to avoid the in-kernel calls to the
sys_readahead() syscall. The ksys_ prefix denotes that this function is
meant as a drop-in replacement for the syscall. In particular, it uses the
same calling convention as sys_readahead().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Signed-off-by: NDominik Brodowski <linux@dominikbrodowski.net>

Using this helper allows us to avoid the in-kernel calls to the
sys_mmap_pgoff() syscall. The ksys_ prefix denotes that this function is
meant as a drop-in replacement for the syscall. In particular, it uses the
same calling convention as sys_mmap_pgoff().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Signed-off-by: NDominik Brodowski <linux@dominikbrodowski.net>

Using the ksys_fadvise64_64() helper allows us to avoid the in-kernel
calls to the sys_fadvise64_64() syscall. The ksys_ prefix denotes that
this function is meant as a drop-in replacement for the syscall. In
particular, it uses the same calling convention as ksys_fadvise64_64().

Some compat stubs called sys_fadvise64(), which then just passed through
the arguments to sys_fadvise64_64(). Get rid of this indirection, and call
ksys_fadvise64_64() directly.

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Signed-off-by: NDominik Brodowski <linux@dominikbrodowski.net>

Using the ksys_fallocate() wrapper allows us to get rid of in-kernel
calls to the sys_fallocate() syscall. The ksys_ prefix denotes that this
function is meant as a drop-in replacement for the syscall. In
particular, it uses the same calling convention as sys_fallocate().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDominik Brodowski <linux@dominikbrodowski.net>

Using the ksys_p{read,write}64() wrappers allows us to get rid of
in-kernel calls to the sys_pread64() and sys_pwrite64() syscalls.
The ksys_ prefix denotes that this function is meant as a drop-in
replacement for the syscall. In particular, it uses the same calling
convention as sys_p{read,write}64().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDominik Brodowski <linux@dominikbrodowski.net>

Using the ksys_truncate() wrapper allows us to get rid of in-kernel
calls to the sys_truncate() syscall. The ksys_ prefix denotes that this
function is meant as a drop-in replacement for the syscall. In
particular, it uses the same calling convention as sys_truncate().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDominik Brodowski <linux@dominikbrodowski.net>

Using this helper allows us to avoid the in-kernel calls to the
sys_sync_file_range() syscall. The ksys_ prefix denotes that this function
is meant as a drop-in replacement for the syscall. In particular, it uses
the same calling convention as sys_sync_file_range().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDominik Brodowski <linux@dominikbrodowski.net>

Using the ksys_ftruncate() wrapper allows us to get rid of in-kernel
calls to the sys_ftruncate() syscall. The ksys_ prefix denotes that this
function is meant as a drop-in replacement for the syscall. In
particular, it uses the same calling convention as sys_ftruncate().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDominik Brodowski <linux@dominikbrodowski.net>

The old wait_on_atomic_t() is going to get removed, use the more
flexible wait_var_event() API instead.

And while there, fix a bug and add the missing wakeup...
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Mark noticed that the change to sibling_list changed some iteration
semantics; because previously we used group_list as list entry,
sibling events would always have an empty sibling_list.

But because we now use sibling_list for both list head and list entry,
siblings will report as having siblings.

Fix this with a custom for_each_sibling_event() iterator.

Fixes: 8343aae6 ("perf/core: Remove perf_event::group_entry")
Reported-by: NMark Rutland <mark.rutland@arm.com>
Suggested-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: vincent.weaver@maine.edu
Cc: alexander.shishkin@linux.intel.com
Cc: torvalds@linux-foundation.org
Cc: alexey.budankov@linux.intel.com
Cc: valery.cherepennikov@intel.com
Cc: eranian@google.com
Cc: acme@redhat.com
Cc: linux-tip-commits@vger.kernel.org
Cc: davidcc@google.com
Cc: kan.liang@intel.com
Cc: Dmitry.Prohorov@intel.com
Cc: jolsa@redhat.com
Link: https://lkml.kernel.org/r/20180315170129.GX4043@hirez.programming.kicks-ass.net

Mark noticed that the change to sibling_list changed some iteration
semantics; because previously we used group_list as list entry,
sibling events would always have an empty sibling_list.

But because we now use sibling_list for both list head and list entry,
siblings will report as having siblings.

Fix this with a custom for_each_sibling_event() iterator.

Fixes: 8343aae6 ("perf/core: Remove perf_event::group_entry")
Reported-by: NMark Rutland <mark.rutland@arm.com>
Suggested-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: vincent.weaver@maine.edu
Cc: alexander.shishkin@linux.intel.com
Cc: torvalds@linux-foundation.org
Cc: alexey.budankov@linux.intel.com
Cc: valery.cherepennikov@intel.com
Cc: eranian@google.com
Cc: acme@redhat.com
Cc: linux-tip-commits@vger.kernel.org
Cc: davidcc@google.com
Cc: kan.liang@intel.com
Cc: Dmitry.Prohorov@intel.com
Cc: jolsa@redhat.com
Link: https://lkml.kernel.org/r/20180315170129.GX4043@hirez.programming.kicks-ass.net

Now that all the grouping is done with RB trees, we no longer need
group_entry and can replace the whole thing with sibling_list.
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Carrillo-Cisneros <davidcc@google.com>
Cc: Dmitri Prokhorov <Dmitry.Prohorov@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valery Cherepennikov <valery.cherepennikov@intel.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

If a JTAG probe is connected to a MIPS cluster, then the CPC detects it
and latches the CPC.STAT_CONF.EJTAG_PROBE bit to 1. While set,
attempting to send a power-down command to a core will be blocked, and
the CPC will instead send the core to clock-off state. This can
interfere with systems fully entering a low power state where all cores,
CM, GIC, etc are powered down.

Detect that a JTAG probe is / has been connected to the cluster and
block the suspend attempt.

Attempting to suspend the system while a JTAG probe is connected now
yields:
 # echo mem > /sys/power/state
 [   11.654000] PM: Syncing filesystems ... done.
 [   11.658000] JTAG probe is connected - abort suspend
 -sh: echo: write error: Operation not permitted
 #

To restore suspend, the JTAG probe should be disconnected or put into
quiescent state. Platform code can then clear the
CPC.STAT_CONF.EJTAG_PROBE bit.
Reported-by: NEd Blake <ed.blake@sondrel.com>
Signed-off-by: NMatt Redfearn <matt.redfearn@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/18641/Signed-off-by: NJames Hogan <jhogan@kernel.org>

The generic MIPS implementations of halting, powering down or restarting
the system all hang using a busy loop as a last resort. We have many
platforms which avoid this loop by implementing their own, many using
some variation upon executing a wait instruction to lower CPU power
usage if we reach this point.

In order to prepare for cleaning up these various custom implementations
of the same thing, this patch makes the generic machine_halt(),
machine_power_off() & machine_restart() functions each make use of the
wait instruction to lower CPU power usage in cases where we know that
the wait instruction is available. If wait isn't known to be supported
then we fall back to calling cpu_wait(), and if we don't have a
cpu_wait() callback then we effectively continue using a busy loop.

In effect the new machine_hang() function provides a superset of the
functionality that the various platforms currently provide differing
subsets of.
Signed-off-by: NPaul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17178/Signed-off-by: NJames Hogan <jhogan@kernel.org>

Commit a3e6c1ef ("MIPS: IRQ: Fix disable_irq on CPU IRQs") fixes an
issue where disable_irq did not actually disable the irq. The bug caused
our IPIs to not be disabled, which actually is the correct behavior.

With the addition of commit a3e6c1ef ("MIPS: IRQ: Fix disable_irq on
CPU IRQs"), the IPIs were getting disabled going into suspend, thus
schedule_ipi() was not being called. This caused deadlocks where
schedulable task were not being scheduled and other cpus were waiting
for them to do something.

Add the IRQF_NO_SUSPEND flag so an irq_disable will not be called on the
IPIs during suspend.
Signed-off-by: NJustin Chen <justinpopo6@gmail.com>
Fixes: a3e6c1ef ("MIPS: IRQ: Fix disabled_irq on CPU IRQs")
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17385/
[jhogan@kernel.org: checkpatch: wrap long lines and fix commit refs]
Signed-off-by: NJames Hogan <jhogan@kernel.org>

Indicate that CRC32 and CRC32C instuctions are supported by the CPU
through elf_hwcap flags.

This will be used by a follow-up commit that introduces crc32(c) crypto
acceleration modules and is required by GENERIC_CPU_AUTOPROBE feature.
Signed-off-by: NMarcin Nowakowski <marcin.nowakowski@mips.com>
Signed-off-by: NJames Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/18600/

Rewrite the comparison in `else if` statement, case where `min_low_pfn >
ARCH_PFN_OFFSET` has already been checked in the first `if` statement:

  if (min_low_pfn > ARCH_PFN_OFFSET) {

Fix non-fatal warning during compilation using W=1:

arch/mips/kernel/setup.c: In function ‘bootmem_init’:
arch/mips/kernel/setup.c:461:25: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
  } else if (min_low_pfn < ARCH_PFN_OFFSET) {
                         ^
Signed-off-by: NMathieu Malaterre <malat@debian.org>
Reviewed-by: NJames Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/18176/Signed-off-by: NJames Hogan <jhogan@kernel.org>

Fix non-fatal warning during compilation using W=1:

arch/mips/kernel/setup.c:158:13: warning: no previous prototype for ‘memory_region_available’ [-Wmissing-prototypes]
 bool __init memory_region_available(phys_addr_t start, phys_addr_t size)
             ^~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: NMathieu Malaterre <malat@debian.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/18175/
[jhogan@kernel.org: tweak whitespace]
Signed-off-by: NJames Hogan <jhogan@kernel.org>

Commit 73fbc1eb ("MIPS: fix mem=X@Y commandline processing") added a
fix to ensure that the memory range between PHYS_OFFSET and low memory
address specified by mem= cmdline argument is not later processed by
free_all_bootmem.  This change was incorrect for systems where the
commandline specifies more than 1 mem argument, as it will cause all
memory between PHYS_OFFSET and each of the memory offsets to be marked
as reserved, which results in parts of the RAM marked as reserved
(Creator CI20's u-boot has a default commandline argument 'mem=256M@0x0
mem=768M@0x30000000').

Change the behaviour to ensure that only the range between PHYS_OFFSET
and the lowest start address of the memories is marked as protected.

This change also ensures that the range is marked protected even if it's
only defined through the devicetree and not only via commandline
arguments.
Reported-by: NMathieu Malaterre <mathieu.malaterre@gmail.com>
Signed-off-by: NMarcin Nowakowski <marcin.nowakowski@mips.com>
Fixes: 73fbc1eb ("MIPS: fix mem=X@Y commandline processing")
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # v4.11+
Tested-by: NMathieu Malaterre <malat@debian.org>
Patchwork: https://patchwork.linux-mips.org/patch/18562/Signed-off-by: NJames Hogan <jhogan@kernel.org>

Remove the __init annotation from bmips_cpu_setup() to avoid the
following warning.

WARNING: vmlinux.o(.text+0x35c950): Section mismatch in reference from the function brcmstb_pm_s3() to the function .init.text:bmips_cpu_setup()
The function brcmstb_pm_s3() references
the function __init bmips_cpu_setup().
This is often because brcmstb_pm_s3 lacks a __init
annotation or the annotation of bmips_cpu_setup is wrong.
Signed-off-by: NJaedon Shin <jaedon.shin@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: linux-mips@linux-mips.org
Reviewed-by: NJames Hogan <jhogan@kernel.org>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/18589/Signed-off-by: NJames Hogan <jhogan@kernel.org>

This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

    for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
        L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
        for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
    done

with de-mangling cleanups yet to come.

NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do.  But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.

The next patch from Al will sort out the final differences, and we
should be all done.
Scripted-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Reading mips_cpc_base value from the DT allows each platform to
define it according to its needs. This is especially convenient
for MIPS_GENERIC kernel where this kind of information should be
determined in runtime.

Use mti,mips-cpc compatible string with just a reg property to
specify the register location for your platform.
Signed-off-by: NPaul Burton <paul.burton@mips.com>
Signed-off-by: NMiodrag Dinic <miodrag.dinic@mips.com>
Signed-off-by: NAleksandar Markovic <aleksandar.markovic@mips.com>
Cc: linux-mips@linux-mips.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/18513/Signed-off-by: NJames Hogan <jhogan@kernel.org>

The merge of commit f875a832 ("MIPS: Abstract CPU core & VP(E) ID
access through accessor functions") ended up creating a duplicate
assignment of core during the rebase on commit bac06cf0 ("MIPS:
smp-cps: Fix potentially uninitialised value of core"). Remove the
duplicate.

Fixes: f875a832 ("MIPS: Abstract CPU core & VP(E) ID access through accessor functions")
Signed-off-by: NMatt Redfearn <matt.redfearn@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17955/Signed-off-by: NJames Hogan <jhogan@kernel.org>

Commit 17278a91 ("MIPS: CPS: Fix r1 .set mt assembler warning")
added .set MIPS_ISA_LEVEL_RAW to silence warnings about .set mt on r1,
however this can result in a MOVE being encoded as a 64-bit DADDU
instruction on certain version of binutils (e.g. 2.22), and reserved
instruction exceptions at runtime on 32-bit hardware.

Reduce the sizes of the push/pop sections to include only instructions
that are part of the MT ASE or which won't convert to 64-bit
instructions after .set mips64r2/mips64r6.
Reported-by: NGreg Ungerer <gerg@linux-m68k.org>
Fixes: 17278a91 ("MIPS: CPS: Fix r1 .set mt assembler warning")
Signed-off-by: NJames Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 4.15
Tested-by: NGreg Ungerer <gerg@linux-m68k.org>
Patchwork: https://patchwork.linux-mips.org/patch/18578/

Now that the DT core code handles bootmem arches, we can remove the MIPS
specific early_init_dt_alloc_memory_arch function.

Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Signed-off-by: NRob Herring <robh@kernel.org>

Currently the bits to be masked when watchhi is read is defined inline
for each register. To avoid this, define the bits once and mask each
register with that value.
Signed-off-by: NMatt Redfearn <matt.redfearn@mips.com>
Acked-by: NDavid Daney <david.daney@cavium.com>
Reviewed-by: NJames Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/18158/Signed-off-by: NJames Hogan <jhogan@kernel.org>

Currently the bits to be set in the watchhi register in addition to that
requested by the user is defined inline for each register. To avoid
this, define the bits once and or that in for each register.
Signed-off-by: NMatt Redfearn <matt.redfearn@mips.com>
Acked-by: NDavid Daney <david.daney@cavium.com>
Reviewed-by: NJames Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/18157/Signed-off-by: NJames Hogan <jhogan@kernel.org>

The siginfo structure has all manners of holes with the result that a
structure initializer is not guaranteed to initialize all of the bits.
As we have to copy the structure to userspace don't even try to use
a structure initializer.  Instead use clear_siginfo followed by initializing
selected fields.  This gives a guarantee that uninitialized kernel memory
is not copied to userspace.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

For reference:
* https://www.kernel.org/doc/html/latest/doc-guide/kernel-doc.html#function-documentation

Fix non-fatal warning:

arch/mips/kernel/branch.c:418: warning: Excess function parameter 'returns' description in '__compute_return_epc_for_insn'
Signed-off-by: NMathieu Malaterre <malat@debian.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Maciej W. Rozycki <macro@mips.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/18031/
[jhogan@kernel.org: Expand subject slightly]
Signed-off-by: NJames Hogan <jhogan@kernel.org>

Platforms using DT will typically call __dt_setup_arch from
plat_mem_setup. This in turn calls early_init_dt_scan. When
CONFIG_CMDLINE is set, this leads to its value being copied into
boot_command_line by early_init_dt_scan_chosen. If this happens before
the code setting up boot_command_line in arch_mem_init runs, that code
will go on to append CONFIG_CMDLINE (via builtin_cmdline) to
boot_command_line again, duplicating it. For some command line
parameters (eg. earlycon) this can be a problem. Set up
boot_command_line before early_init_dt_scan_chosen gets called such that
it will not write CONFIG_CMDLINE in this scenario & the arguments aren't
duplicated.
Signed-off-by: NPaul Burton <paul.burton@mips.com>
Acked-by: NMathieu Malaterre <malat@debian.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Maarten ter Huurne <maarten@treewalker.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/18483/Signed-off-by: NJames Hogan <jhogan@kernel.org>

Replace pointer comparison to 0 with NULL in prepare_ftrace_return
to improve code readability. Identified with coccinelle script
'badzero.cocci'.
Signed-off-by: NMathieu Malaterre <malat@debian.org>
Reviewed-by: NJames Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/18494/Signed-off-by: NJames Hogan <jhogan@kernel.org>

Among the existing architecture specific versions of
copy_siginfo_to_user32 there are several different implementation
problems.  Some architectures fail to handle all of the cases in in
the siginfo union.  Some architectures perform a blind copy of the
siginfo union when the si_code is negative.  A blind copy suggests the
data is expected to be in 32bit siginfo format, which means that
receiving such a signal via signalfd won't work, or that the data is
in 64bit siginfo and the code is copying nonsense to userspace.

Create a single instance of copy_siginfo_to_user32 that all of the
architectures can share, and teach it to handle all of the cases in
the siginfo union correctly, with the assumption that siginfo is
stored internally to the kernel is 64bit siginfo format.

A special case is made for x86 x32 format.  This is needed as presence
of both x32 and ia32 on x86_64 results in two different 32bit signal
formats.  By allowing this small special case there winds up being
exactly one code base that needs to be maintained between all of the
architectures.  Vastly increasing the testing base and the chances of
finding bugs.

As the x86 copy of copy_siginfo_to_user32 the call of the x86
signal_compat_build_tests were moved into sigaction_compat_abi, so
that they will keep running.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

The function copy_siginfo_from_user32 is used for two things, in ptrace
since the dawn of siginfo for arbirarily modifying a signal that
user space sees, and in sigqueueinfo to send a signal with arbirary
siginfo data.

Create a single copy of copy_siginfo_from_user32 that all architectures
share, and teach it to handle all of the cases in the siginfo union.

In the generic version of copy_siginfo_from_user32 ensure that all
of the fields in siginfo are initialized so that the siginfo structure
can be safely copied to userspace if necessary.

When copying the embedded sigval union copy the si_int member.  That
ensures the 32bit values passes through the kernel unchanged.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

Since commit 68923cdc ("MIPS: CM: Add cluster & block args to
mips_cm_lock_other()"), mips_smp_send_ipi_mask() has used
mips_cm_lock_other_cpu() with each CPU number, rather than
mips_cm_lock_other() with the first VPE in each core. Prior to r6,
multicore multithreaded systems such as dual-core dual-thread
interAptivs with CPU Idle enabled (e.g. MIPS Creator Ci40) results in
mips_cm_lock_other() repeatedly hitting WARN_ON(vp != 0).

There doesn't appear to be anything fundamentally wrong about passing a
non-zero VP/VPE number, even if it is a core's region that is locked
into the other region before r6, so remove that particular WARN_ON().

Fixes: 68923cdc ("MIPS: CM: Add cluster & block args to mips_cm_lock_other()")
Signed-off-by: NJames Hogan <jhogan@kernel.org>
Reviewed-by: NPaul Burton <paul.burton@mips.com>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org # 4.14+
Patchwork: https://patchwork.linux-mips.org/patch/17883/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Fix an API loophole introduced with commit 9791554b ("MIPS,prctl:
add PR_[GS]ET_FP_MODE prctl options for MIPS"), where the caller of
prctl(2) is incorrectly allowed to make a change to CP0.Status.FR or
CP0.Config5.FRE register bits even if CONFIG_MIPS_O32_FP64_SUPPORT has
not been enabled, despite that an executable requesting the mode
requested via ELF file annotation would not be allowed to run in the
first place, or for n64 and n64 ABI tasks which do not have non-default
modes defined at all.  Add suitable checks to `mips_set_process_fp_mode'
and bail out if an invalid mode change has been requested for the ABI in
effect, even if the FPU hardware or emulation would otherwise allow it.

Always succeed however without taking any further action if the mode
requested is the same as one already in effect, regardless of whether
any mode change, should it be requested, would actually be allowed for
the task concerned.
Signed-off-by: NMaciej W. Rozycki <macro@mips.com>
Fixes: 9791554b ("MIPS,prctl: add PR_[GS]ET_FP_MODE prctl options for MIPS")
Reviewed-by: NPaul Burton <paul.burton@mips.com>
Cc: James Hogan <james.hogan@mips.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org # 4.0+
Patchwork: https://patchwork.linux-mips.org/patch/17800/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Complement commit c23b3d1a ("MIPS: ptrace: Change GP regset to use
correct core dump register layout") and also reject outsized
PTRACE_SETREGSET requests to the NT_PRFPREG regset, like with the
NT_PRSTATUS regset.
Signed-off-by: NMaciej W. Rozycki <macro@mips.com>
Fixes: c23b3d1a ("MIPS: ptrace: Change GP regset to use correct core dump register layout")
Cc: James Hogan <james.hogan@mips.com>
Cc: Paul Burton <Paul.Burton@mips.com>
Cc: Alex Smith <alex@alex-smith.me.uk>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org # v3.17+
Patchwork: https://patchwork.linux-mips.org/patch/17930/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>