Apart from adding the helper function itself, the rest of the kernel is
converted mechanically using:

  git grep -l 'atomic_inc.*mm_count' | xargs sed -i 's/atomic_inc(&\(.*\)->mm_count);/mmgrab\(\1\);/'
  git grep -l 'atomic_inc.*mm_count' | xargs sed -i 's/atomic_inc(&\(.*\)\.mm_count);/mmgrab\(\&\1\);/'

This is needed for a later patch that hooks into the helper, but might
be a worthwhile cleanup on its own.

(Michal Hocko provided most of the kerneldoc comment.)

Link: http://lkml.kernel.org/r/20161218123229.22952-1-vegard.nossum@oracle.comSigned-off-by: NVegard Nossum <vegard.nossum@oracle.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When a non-cooperative userfaultfd monitor copies pages in the
background, it may encounter regions that were already unmapped.
Addition of UFFD_EVENT_UNMAP allows the uffd monitor to track precisely
changes in the virtual memory layout.

Since there might be different uffd contexts for the affected VMAs, we
first should create a temporary representation for the unmap event for
each uffd context and then notify them one by one to the appropriate
userfault file descriptors.

The event notification occurs after the mmap_sem has been released.

[arnd@arndb.de: fix nommu build]
  Link: http://lkml.kernel.org/r/20170203165141.3665284-1-arnd@arndb.de
[mhocko@suse.com: fix nommu build]
  Link: http://lkml.kernel.org/r/20170202091503.GA22823@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/1485542673-24387-3-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by: NMike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NHillf Danton <hillf.zj@alibaba-inc.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove duplicated include.

Fixes: 7c0f6ba6 ("Replace <asm/uaccess.h> with <linux/uaccess.h> globally")
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Markus Elfring <elfring@users.sourceforge.net>
Cc: Wei Yongjun <weiyongjun1@huawei.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15213/Signed-off-by: NJames Hogan <james.hogan@imgtec.com>

Unify definitions for MIPS performance counter register fields in
mipsregs.h rather than duplicating them in perf_events and oprofile.
This will allow future patches to use them to expose performance
counters to KVM guests.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
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: linux-kernel@vger.kernel.org
Cc: oprofile-list@lists.sf.net
Patchwork: https://patchwork.linux-mips.org/patch/15212/Signed-off-by: NJames Hogan <james.hogan@imgtec.com>

Since commit 4bcc595c ("printk: reinstate KERN_CONT for printing
continuation lines") the output of counter synchornisation has been
split across lines:
[ 0.665181] Synchronize counters for CPU 1:
[ 0.678578] done.

Fix this by using pr_cont, and replace printk with pr_info.
Signed-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15195/Signed-off-by: NJames Hogan <james.hogan@imgtec.com>

Commit dda45f70 ("MIPS: Switch to the irq_stack in interrupts")
changed both the normal and vectored interrupt handlers. Unfortunately
the vectored version, "except_vec_vi_handler", was incorrectly modified
to unconditionally jal to plat_irq_dispatch, rather than doing a jalr to
the vectored handler that has been set up. This is ok for many platforms
which set the vectored handler to plat_irq_dispatch anyway, but will
cause problems with platforms that use other handlers.

Fixes: dda45f70 ("MIPS: Switch to the irq_stack in interrupts")
Signed-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15110/Signed-off-by: NJames Hogan <james.hogan@imgtec.com>

The recently added MIPS cacheinfo support used a macro populate_cache()
to populate the cacheinfo structures depending on which caches are
present. However the macro contains multiple statements without
enclosing them in a do {} while (0) loop, so the L2 and L3 cache
conditionals in populate_cache_leaves() only conditionalised the first
statement in the macro.

This overflows the buffer allocated by detect_cache_attributes(),
resulting in boot failures under QEMU where neither the L2 or L2 caches
are present.

Enclose the macro statements in a do {} while (0) block to keep the
whole macro inside the conditionals.

Fixes: ef462f3b ("MIPS: Add cacheinfo support")
Reported-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Tested-by: NGuenter Roeck <linux@roeck-us.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Justin Chen <justin.chen@broadcom.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: bcm-kernel-feedback-list@broadcom.com
Patchwork: https://patchwork.linux-mips.org/patch/15276/

Use the new nsec based cputime accessors as part of the whole cputime
conversion from cputime_t to nsecs.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Link: http://lkml.kernel.org/r/1485832191-26889-12-git-send-email-fweisbec@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

* Return an error code without storing it in an intermediate variable.

* Delete the local variable "result" which became unnecessary with
  this refactoring.
Signed-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: linux-mips@linux-mips.org
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: kernel-janitors@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/15073/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

A local variable was set to an error code in one case before a concrete
error situation was detected. Thus move the corresponding assignment into
an if branch to indicate a software failure there.

This issue was detected by using the Coccinelle software.
Signed-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: linux-mips@linux-mips.org
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: kernel-janitors@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/15072/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

* Return a failure indication without storing it
  in an intermediate variable.

* Delete the local variable "error" which became unnecessary
  with this refactoring.
Signed-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: linux-mips@linux-mips.org
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: kernel-janitors@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/15071/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

64-bit pre-r6 kernels output the following broken printk continuation
lines during boot:

Checking for the multiply/shift bug...
no.
Checking for the daddiu bug...
no.
Checking for the daddi bug...
no.

Fix the printk continuations in cpu-bugs64.c to use pr_cont to restore
the correct output:

Checking for the multiply/shift bug... no.
Checking for the daddiu bug... no.
Checking for the daddi bug... no.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14916/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Now that EXPORT_SYMBOL can be used from assembly source, move the
EXPORT_SYMBOL invocations for the copy_page & clear_page functions to be
alongside their definitions.

With this change there are no longer any symbols exported from
mips_ksyms.c so remove the file.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14515/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Now that EXPORT_SYMBOL can be used from assembly source, move the
EXPORT_SYMBOL invocations for the memcpy & memset functions & variants
thereof to be alongside their definitions.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14514/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Now that EXPORT_SYMBOL can be used from assembly source, move the
EXPORT_SYMBOL invocations for the strlen*, strnlen* & strncpy* functions
to be alongside their definitions.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14513/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Now that EXPORT_SYMBOL can be used from assembly source, move the
EXPORT_SYMBOL invocations for the csum_partial_* functions to be
alongside their definitions.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14512/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

It's unclear to me why this wasn't always the case, but move the
EXPORT_SYMBOL invocation for invalid_pte_table to be alongside its
definition.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14511/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Now that EXPORT_SYMBOL can be used from assembly source, move the
EXPORT_SYMBOL invocation for _mcount to be alongside its definition.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14525/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Now that EXPORT_SYMBOL can be used from assembly source, move the
EXPORT_SYMBOL invocations for _save_fp & _save_msa to be alongside their
definitions.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14509/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Arch-specific implementation of arch_uprobe_copy_ixol is expected to
override the weak implementation in generic code.
As currently both implementations are marked as weak, it is up to the
linker to chose one. Remove the __weak attribute from MIPS code to make
sure the correct version is used.

Fixes: 40e084a5 ("MIPS: Add uprobes support.")
Signed-off-by: NMarcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14660/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Add cacheinfo support for MIPS architectures.

Use information from the cpuinfo_mips struct to populate the
cacheinfo struct. This allows an architecture agnostic approach,
however this also means if cache information is not properly
populated within the cpuinfo_mips struct, there is nothing
we can do. (I.E. c-r3k.c)
Signed-off-by: NJustin Chen <justin.chen@broadcom.com>
Cc: f.fainelli@gmail.com
Cc: linux-mips@linux-mips.org
Cc: bcm-kernel-feedback-list@broadcom.com
Patchwork: https://patchwork.linux-mips.org/patch/14650/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Print details of the new kexec image loaded.

Based on the original code from
commit 221f2c77 ("arm64/kexec: Add pr_debug output")
Signed-off-by: NMarcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14614/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Do not reserve memory for the crashkernel if the commandline argument
points to a wrong location. This can happen if the location is specified
wrong or if the same commandline is reused when starting the crashkernel
- in the latter case the reserved memory would point to the location
from which the crashkernel is executing.
Signed-off-by: NMarcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14612/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

When a memory offset is specified through the commandline, add the
memory in range PHYS_OFFSET:Y as reserved memory area.
Otherwise the bootmem allocator is initialised with low page equal to
min_low_pfn = PHYS_OFFSET, and in free_all_bootmem will process pages
starting from min_low_pfn instead of PFN(Y).
Signed-off-by: NMarcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14613/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

If the DTB is located in the target memory area for the relocated kernel
it needs to be relocated as well before kernel relocation takes place.

After copying the DTB use the new plat_fdt_relocated() API from the
relocated kernel to ensure the relocated kernel updates any information
that it may have cached about the location of the DTB.

plat_fdt_relocated is declared as a weak symbol so that platforms that
do not require it do not need to implement the method.
Signed-off-by: NMarcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14616/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

early_init_fdt_reserve_self is used to tell the boot memory allocator
that a memory is occupied by the DTB, so add it in the MIPS init code to
ensure information about the DTB is added to the boot memory array.
Signed-off-by: NMarcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14610/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Current init code initialises bootmem allocator with all of the low
memory that it assumes is available, but does not check for reserved
memory block, which can lead to corruption of data that may be stored
there.
Move bootmem's allocation map to a location that does not cross any
reserved regions
Signed-off-by: NMarcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14609/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Memories managed through boot_mem_map are generally expected to define
non-crossing areas. However, if part of a larger memory block is marked
as reserved, it would still be added to bootmem allocator as an
available block and could end up being overwritten by the allocator.

Prevent this by explicitly marking the memory as reserved it if exists
in the range used by bootmem allocator.
Signed-off-by: NMarcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14608/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

When KEXEC is enabled but crashkernel details are not passed through the
kernel commandline unnecessary resources are requested (start==end==0)
Signed-off-by: NMarcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14607/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Current register dump methods for MIPS are implemented inside ptrace
methods, but there will be other uses in the kernel for them, so keep
them separately in process.c and use those definitions for ptrace
instead.
Signed-off-by: NMarcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14587/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

SMP_DUMP has been added as a new IPI signal when kexec support was added
for Cavium Octeon CPUs ('commit 7aa1c8f4 ("MIPS: kdump: Add support")'.
However, the new signal doesn't appear to ever have a proper handler
added (octeon_message_functions[] array has an empty handler for it),
and generic IPI handlers now trigger a BUG() on unhandled signal.

As the method is unused remove it completely and replace its only
invocation with a smp_call_function().

[ralf@linux-mips.org: Renumber SMP_ASK_C0COUNT to avoid numbering gaps.]
Signed-off-by: NMarcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14630/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The r2_emul_return field in struct thread_info was used in order to take
an alternate codepath when returning to userland, which (besides not
implementing certain features) effectively used the eretnc instruction
in place of eret. The difference is that eretnc doesn't clear LLBit, and
therefore doesn't cause a linked load & store sequence to fail due to
emulation like eret would.

The reason eret would usually be used to clear LLBit is so that after
context switching we ensure that a load performed by one task doesn't
influence another task. However commit 7c151d3d ("MIPS: Make use of
the ERETNC instruction on MIPS R6") which introduced the r2_emul_return
field and conditional use of eretnc also for some reason began
explicitly clearing LLBit during context switches - despite retaining
the use of eret for everything but returns from the pre-r6 instruction
emulation code.

As LLBit is cleared upon context switches anyway, simplify this by using
eretnc unconditionally for MIPSr6 kernels. This allows us to remove the
4 byte r2_emul_return boolean from struct thread_info, simplify the
return to user code in entry.S and avoid the overhead of tracking &
checking state which we don't need.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14408/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

On systems with CM3, we must ensure that the L1 & L2 ECC enables are set
to the same value. This is presumed by the hardware & cache corruption
can occur when it is not the case. Support enabling & disabling the L2
ECC checking on CM3 systems where this is controlled via a GCR, and
ensure that it matches the state of L1 ECC checking. Remove I6400 from
the switch statement it will no longer hit, and which was incorrect
since the L2 ECC enable bit isn't in the CP0 ErrCtl register.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14413/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

MIPS instructions MULTU, MADDU and MSUBU emulation requires registers HI/LO
to be converted to signed 32bits before 64bit sign extension on MIPS64.

Bug was found on running MIPS32 R2 test application on MIPS64 R6 kernel.

Fixes: b0a668fb ("MIPS: kernel: mips-r2-to-r6-emul: Add R2 emulator for MIPS R6")
Signed-off-by: NLeonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Reported-by: Nikola.Veljkovic@imgtec.com
Cc: paul.burton@imgtec.com
Cc: yamada.masahiro@socionext.com
Cc: akpm@linux-foundation.org
Cc: andrea.gelmini@gelma.net
Cc: macro@imgtec.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14043/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

While we properly disabled the per-CPU timer interrupt, we also need to
make sure that all interrupts that can possibly have this CPU in their
smp_affinity mask also have a chance to see this interrupt migrated to a
CPU not being taken offline.

[ralf@linux-mips.org: Fix merge conflict.]

Fixes: 230b6ff5 ("MIPS: BMIPS: Mask off timer IRQs when hot-unplugging a CPU")
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Cc: cernekee@gmail.com
Cc: jaedon.shin@gmail.com
Cc: justinpopo6@gmail.com
Cc: tglx@linutronix.de
Cc: marc.zyngier@arm.com
Cc: jason@lakedaemon.net
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14488/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

If there is no online CPU within a core which could receive the IPI to
start another VP in that core, a BUG() is triggered. Instead print a
warning and gracefully handle the failure such that the system remains
usable, albeit without the requested secondary CPU.
Signed-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Qais Yousef <qsyousef@gmail.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/14504/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The previous commit made cpu_callin_map redundant, since it is no longer
used to signal secondary CPUs starting, or going offline. Remove it now.
Signed-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Qais Yousef <qsyousef@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: Yang Shi <yang.shi@windriver.com>
Cc: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14503/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

If a secondary CPU failed to start, for any reason, the CPU requesting
the secondary to start would get stuck in the loop waiting for the
secondary to be present in the cpu_callin_map.

Rather than that, use a completion event to signal that the secondary
CPU has started and is waiting to synchronise counters.

Since the CPU presence will no longer be marked in cpu_callin_map,
remove the redundant test from arch_cpu_idle_dead().
Signed-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Qais Yousef <qsyousef@gmail.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Marcin Nowakowski <marcin.nowakowski@imgtec.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/14502/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

is_jump_ins() checks for plain jump ("j") instructions since commit
e7438c4b ("MIPS: Fix sibling call handling in get_frame_info") but
that commit didn't make the same change to the microMIPS code, leaving
it inconsistent with the MIPS32/MIPS64 code. Handle the microMIPS
encoding of the jump instruction too such that it behaves consistently.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Fixes: e7438c4b ("MIPS: Fix sibling call handling in get_frame_info")
Cc: Tony Wu <tung7970@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # v3.10+
Patchwork: https://patchwork.linux-mips.org/patch/14533/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

get_frame_info() calculates the offset of the return address within a
stack frame simply by dividing a the bottom 16 bits of the instruction,
treated as a signed integer, by the size of a long. Whilst this works
for MIPS32 & MIPS64 ISAs where the sw or sd instructions are used, it's
incorrect for microMIPS where encodings differ. The result is that we
typically completely fail to unwind the stack on microMIPS.

Fix this by adjusting is_ra_save_ins() to calculate the return address
offset, and take into account the various different encodings there in
the same place as we consider whether an instruction is storing the
ra/$31 register.

With this we are now able to unwind the stack for kernels targetting the
microMIPS ISA, for example we can produce:

    Call Trace:
    [<80109e1f>] show_stack+0x63/0x7c
    [<8011ea17>] __warn+0x9b/0xac
    [<8011ea45>] warn_slowpath_fmt+0x1d/0x20
    [<8013fe53>] register_console+0x43/0x314
    [<8067c58d>] of_setup_earlycon+0x1dd/0x1ec
    [<8067f63f>] early_init_dt_scan_chosen_stdout+0xe7/0xf8
    [<8066c115>] do_early_param+0x75/0xac
    [<801302f9>] parse_args+0x1dd/0x308
    [<8066c459>] parse_early_options+0x25/0x28
    [<8066c48b>] parse_early_param+0x2f/0x38
    [<8066e8cf>] setup_arch+0x113/0x488
    [<8066c4f3>] start_kernel+0x57/0x328
    ---[ end trace 0000000000000000 ]---

Whereas previously we only produced:

    Call Trace:
    [<80109e1f>] show_stack+0x63/0x7c
    ---[ end trace 0000000000000000 ]---
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Fixes: 34c2f668 ("MIPS: microMIPS: Add unaligned access support.")
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # v3.10+
Patchwork: https://patchwork.linux-mips.org/patch/14532/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>