Lingering requests are requests that are sent to the OSD normally but
tracked also after we get a successful request.  This keeps the OSD
connection open and resends the original request if the object moves to
another OSD.  The OSD can then send notification messages back to us
if another client initiates a notify.

This framework will be used by RBD so that the client gets notification
when a snapshot is created by another node or tool.
Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

Signed-off-by: NSage Weil <sage@newdream.net>

Just for consistency's sake.  Fix obsolete comment too.
Signed-off-by: NSage Weil <sage@newdream.net>

In sync_write_wait(), we assume that the newest request is at the
tail of unsafe write list. We should maintain the semantics here.
Signed-off-by: NHenry C Chang <henry_c_chang@tcloudcomputing.com>
Signed-off-by: NSage Weil <sage@newdream.net>

This fixes the list corruption warning like this:

------------[ cut here ]------------
WARNING: at lib/list_debug.c:30 __list_add+0x68/0x81()
Hardware name: X8DTU
list_add corruption. prev->next should be next (ffff880618931250), but was (null). (prev=ffff880c188b9130).
Modules linked in: nfsd lockd nfs_acl auth_rpcgss exportfs ceph libceph libcrc32c sunrpc ipv6 fuse igb i2c_i801 ioatdma i2c_core iTCO_wdt iTCO_vendor_support joydev dca serio_raw usb_storage [last unloaded: scsi_wait_scan]
Pid: 10977, comm: smbd Tainted: G        W  2.6.32.23-170.Elaster.xendom0.fc12.x86_64 #1
Call Trace:
[<ffffffff8105753c>] warn_slowpath_common+0x7c/0x94
[<ffffffff810575ab>] warn_slowpath_fmt+0x41/0x43
[<ffffffff812351a3>] __list_add+0x68/0x81
[<ffffffffa014799d>] ceph_aio_write+0x614/0x8a2 [ceph]
[<ffffffff8111d2a0>] do_sync_write+0xe8/0x125
[<ffffffff81075a1f>] ? autoremove_wake_function+0x0/0x39
[<ffffffff811f21ec>] ? selinux_file_permission+0x5c/0xb3
[<ffffffff811e8521>] ? security_file_permission+0x16/0x18
[<ffffffff8111d864>] vfs_write+0xae/0x10b
[<ffffffff8111d91b>] sys_pwrite64+0x5a/0x76
[<ffffffff81012d32>] system_call_fastpath+0x16/0x1b
---[ end trace 08573eb9f07ff6f4 ]---
Signed-off-by: NHenry C Chang <henry_c_chang@tcloudcomputing.com>
Signed-off-by: NSage Weil <sage@newdream.net>

Signed-off-by: NSage Weil <sage@newdream.net>

The ino32 mount option forces the ceph fs to report 32 bit
ino values.  This is useful for 64 bit kernels with 32 bit userspace.
Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>

This updates the common header files used by the different ceph
related modules. Specifically it adds definitions required by
the rbd watch/notify feature.
Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>

Whoops!
Signed-off-by: NSage Weil <sage@newdream.net>

If we send a request to osd A, and the request's pg remaps to osd B and
then back to A in quick succession, we need to resend the request to A. The
old code was only calling kick_requests after processing all incremental
maps in a message, so it was very possible to not resend a request that
needed to be resent.  This would make the osd eventually time out (at least
with the current default of osd timeouts enabled).

The correct approach is to scan requests on every map incremental.  This
patch refactors the kick code in a few ways:
 - all requests are either on req_lru (in flight), req_unsent (ready to
   send), or req_notarget (currently map to no up osd)
 - mapping always done by map_request (previous map_osds)
 - if the mapping changes, we requeue.  requests are resent only after all
   map incrementals are processed.
 - some osd reset code is moved out of kick_requests into a separate
   function
 - the "kick this osd" functionality is moved to kick_osd_requests, as it
   is unrelated to scanning for request->pg->osd mapping changes
Signed-off-by: NSage Weil <sage@newdream.net>

d_move puts the renamed dentry at the end of d_subdirs, screwing with our
cached dentry directory offsets.  We were just clearing I_COMPLETE to avoid
any possibility of trouble.  However, assigning the renamed dentry an
offset at the end of the directory (to match it's new d_subdirs position)
is sufficient to maintain correct behavior and hold onto I_COMPLETE.

This is especially important for workloads like rsync, which renames files
into place.  Before, we would lose I_COMPLETE and do MDS lookups for each
file.  With this patch we only talk to the MDS on create and rename.
Signed-off-by: NSage Weil <sage@newdream.net>

It used to return -EINVAL because it thought the end was not aligned
to 4 bytes.

Clean up superfluous src < end test in if, the while itself guarantees
that.
Signed-off-by: NTommi Virtanen <tommi.virtanen@dreamhost.com>
Signed-off-by: NSage Weil <sage@newdream.net>

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-mn10300:
  MN10300: atomic_read() should ensure it emits a load
  MN10300: The SMP_ICACHE_INV_FLUSH_RANGE IPI command does not exist
  MN10300: Proper use of macros get_user() in the case of incremented pointers

* 'upstream' of git://git.linux-mips.org/pub/scm/upstream-linus: (26 commits)
  MIPS: Alchemy: Fix reset for MTX-1 and XXS1500
  MIPS: MTX-1: Make au1000_eth probe all PHY addresses
  MIPS: Jz4740: Add HAVE_CLK
  MIPS: Move idle task creation to work queue
  MIPS, Perf-events: Use unsigned delta for right shift in event update
  MIPS, Perf-events: Work with the new callchain interface
  MIPS, Perf-events: Fix event check in validate_event()
  MIPS, Perf-events: Work with the new PMU interface
  MIPS, Perf-events: Work with irq_work
  MIPS: Fix always CONFIG_LOONGSON_UART_BASE=y
  MIPS: Loongson: Fix potentially wrong string handling
  MIPS: Fix GCC-4.6 'set but not used' warning in arch/mips/mm/init.c
  MIPS: Fix GCC-4.6 'set but not used' warning in ieee754int.h
  MIPS: Remove unused code from arch/mips/kernel/syscall.c
  MIPS: Fix GCC-4.6 'set but not used' warning in signal*.c
  MIPS: MSP: Fix MSP71xx bpci interrupt handler return value
  MIPS: Select R4K timer lib for all MSP platforms
  MIPS: Loongson: Remove ad-hoc cmdline default
  MIPS: Clear the correct flag in sysmips(MIPS_FIXADE, ...).
  MIPS: Add an unreachable return statement to satisfy buggy GCCs.
  ...

Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: ce4100: Set pci ops via callback instead of module init
  x86/mm: Fix pgd_lock deadlock
  x86/mm: Handle mm_fault_error() in kernel space
  x86: Don't check for BIOS corruption in first 64K when there's no need to

This reverts the parent commit.  I hate doing that, but it's generating
some discussion ("half of it is right"), and since I am planning on
doing the 2.6.38 release later today we can punt it to stable if
required. Let's not rock the boat right now.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

oom_kill_process() starts with victim_points == 0.  This means that
(most likely) any child has more points and can be killed erroneously.

Also, "children has a different mm" doesn't match the reality, we should
check child->mm != t->mm.  This check is not exactly correct if t->mm ==
NULL but this doesn't really matter, oom_kill_task() will kill them
anyway.

Note: "Kill all processes sharing p->mm" in oom_kill_task() is wrong
too.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since commit 32fd6901 (MIPS: Alchemy: get rid of common/reset.c)
Alchemy-based boards use their own reset function. For MTX-1 and XXS1500,
the reset function pokes at the BCSR.SYSTEM_RESET register, but this does
not work. According to Bruno Randolf, this was not tested when written.

Previously, the generic au1000_restart() routine called the board specific
reset function, which for MTX-1 and XXS1500 did not work, but finally made
a jump to the reset vector, which really triggers a system restart. Fix
reboot for both targets by jumping to the reset vector.
Signed-off-by: NFlorian Fainelli <florian@openwrt.org>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2093/Acked-by: NBruno Randolf <br1@einfach.org>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

When au1000_eth probes the MII bus for PHY address, if we do not set
au1000_eth platform data's phy_search_highest_address, the MII probing
logic will exit early and will assume a valid PHY is found at address 0.
For MTX-1, the PHY is at address 31, and without this patch, the link
detection/speed/duplex would not work correctly.

CC: stable@kernel.org
Signed-off-by: NFlorian Fainelli <florian@openwrt.org>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2111/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Jz4740 supports the clock framework but doesn't have HAVE_CLK defined,
so define it!
Signed-off-by: NMaurus Cuelenaere <mcuelenaere@gmail.com>
To: linux-mips@linux-mips.org
To: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/2112/Acked-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

To avoid forking usermode thread when creating an idle task, move fork_idle
to a work queue.

If kernel starts with maxcpus= option which does not bring all available
cpus online at boot time, idle tasks for offline cpus are not created. If
later offline cpus are hotplugged through sysfs, __cpu_up is called in
the context of the user task, and fork_idle copies its non-zero mm
pointer.  This causes BUG() in per_cpu_trap_init.

This also avoids issues with resource limits of the CPU writing to sysfs,
containers, maybe others.
Signed-off-by: NMaksim Rayskiy <mrayskiy@broadcom.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2070/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Leverage the commit for ARM by Will Deacon:

- 446a5a8b
    ARM: 6205/1: perf: ensure counter delta is treated as unsigned

    Hardware performance counters on ARM are 32-bits wide but atomic64_t
    variables are used to represent counter data in the hw_perf_event structure.

    The armpmu_event_update function right-shifts a signed 64-bit delta variable
    and adds the result to the event count. This can lead to shifting in sign-bits
    if the MSB of the 32-bit counter value is set. This results in perf output
    such as:

     Performance counter stats for 'sleep 20':

     18446744073460670464  cycles             <-- 0xFFFFFFFFF12A6000
            7783773  instructions             #      0.000 IPC
                465  context-switches
                161  page-faults
            1172393  branches

       20.154242147  seconds time elapsed

    This patch ensures that the delta value is treated as unsigned so that the
    right shift sets the upper bits to zero.
Acked-by: NWill Deacon <will.deacon@arm.com>
Acked-by: NDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: NDeng-Cheng Zhu <dengcheng.zhu@gmail.com>
To: a.p.zijlstra@chello.nl
To: fweisbec@gmail.com
To: will.deacon@arm.com
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: wuzhangjin@gmail.com
Cc: paulus@samba.org
Cc: mingo@elte.hu
Cc: acme@redhat.com
Cc: matt@console-pimps.org
Cc: sshtylyov@mvista.com
Patchwork: http://patchwork.linux-mips.org/patch/2015/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This is the MIPS part of the following commits by Frederic Weisbecker:

- f72c1a93
    perf: Factorize callchain context handling

    Store the kernel and user contexts from the generic layer instead
    of archs, this gathers some repetitive code.

- 56962b44
    perf: Generalize some arch callchain code

    - Most archs use one callchain buffer per cpu, except x86 that needs
      to deal with NMIs. Provide a default perf_callchain_buffer()
      implementation that x86 overrides.

    - Centralize all the kernel/user regs handling and invoke new arch
      handlers from there: perf_callchain_user() / perf_callchain_kernel()
      That avoid all the user_mode(), current->mm checks and so...

    - Invert some parameters in perf_callchain_*() helpers: entry to the
      left, regs to the right, following the traditional (dst, src).

- 70791ce9
    perf: Generalize callchain_store()

    callchain_store() is the same on every archs, inline it in
    perf_event.h and rename it to perf_callchain_store() to avoid
    any collision.

    This removes repetitive code.

- c1a65932
    perf: Drop unappropriate tests on arch callchains

    Drop the TASK_RUNNING test on user tasks for callchains as
    this check doesn't seem to make any sense.

    Also remove the tests for !current that is not supposed to
    happen and current->pid as this should be handled at the
    generic level, with exclude_idle attribute.
Reported-by: NWu Zhangjin <wuzhangjin@gmail.com>
Acked-by: NFrederic Weisbecker <fweisbec@gmail.com>
Acked-by: NDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: NDeng-Cheng Zhu <dengcheng.zhu@gmail.com>
To: a.p.zijlstra@chello.nl
To: will.deacon@arm.com
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: paulus@samba.org
Cc: mingo@elte.hu
Cc: acme@redhat.com
Cc: dengcheng.zhu@gmail.com
Cc: matt@console-pimps.org
Cc: sshtylyov@mvista.com
Patchwork: http://patchwork.linux-mips.org/patch/2014/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Ignore events that are in off/error state or belong to a different PMU.

This patch originates from the following commit for ARM by Will Deacon:

- 65b4711f
    ARM: 6352/1: perf: fix event validation

    The validate_event function in the ARM perf events backend has the
    following problems:

    1.) Events that are disabled count towards the cost.
    2.) Events associated with other PMUs [for example, software events or
        breakpoints] do not count towards the cost, but do fail validation,
        causing the group to fail.

    This patch changes validate_event so that it ignores events in the
    PERF_EVENT_STATE_OFF state or that are scheduled for other PMUs.
Acked-by: NWill Deacon <will.deacon@arm.com>
Acked-by: NDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: NDeng-Cheng Zhu <dengcheng.zhu@gmail.com>
To: a.p.zijlstra@chello.nl
To: fweisbec@gmail.com
To: will.deacon@arm.com
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: wuzhangjin@gmail.com
Cc: paulus@samba.org
Cc: mingo@elte.hu
Cc: acme@redhat.com
Cc: dengcheng.zhu@gmail.com
Cc: matt@console-pimps.org
Cc: sshtylyov@mvista.com
Cc: ddaney@caviumnetworks.com
Patchwork: http://patchwork.linux-mips.org/patch/2013/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This is the MIPS part of the following commits by Peter Zijlstra:

- a4eaf7f1
    perf: Rework the PMU methods

    Replace pmu::{enable,disable,start,stop,unthrottle} with
    pmu::{add,del,start,stop}, all of which take a flags argument.

    The new interface extends the capability to stop a counter while
    keeping it scheduled on the PMU. We replace the throttled state with
    the generic stopped state.

    This also allows us to efficiently stop/start counters over certain
    code paths (like IRQ handlers).

    It also allows scheduling a counter without it starting, allowing for
    a generic frozen state (useful for rotating stopped counters).

    The stopped state is implemented in two different ways, depending on
    how the architecture implemented the throttled state:

     1) We disable the counter:
        a) the pmu has per-counter enable bits, we flip that
        b) we program a NOP event, preserving the counter state

     2) We store the counter state and ignore all read/overflow events

For MIPSXX, the stopped state is implemented in the way of 1.b as above.

- 33696fc0
    perf: Per PMU disable

    Changes perf_disable() into perf_pmu_disable().

- 24cd7f54
    perf: Reduce perf_disable() usage

    Since the current perf_disable() usage is only an optimization,
    remove it for now. This eases the removal of the __weak
    hw_perf_enable() interface.

- b0a873eb
    perf: Register PMU implementations

    Simple registration interface for struct pmu, this provides the
    infrastructure for removing all the weak functions.

- 51b0fe39
    perf: Deconstify struct pmu

    sed -ie 's/const struct pmu\>/struct pmu/g' `git grep -l "const struct pmu\>"`
Reported-by: NWu Zhangjin <wuzhangjin@gmail.com>
Acked-by: NDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: NDeng-Cheng Zhu <dengcheng.zhu@gmail.com>
To: a.p.zijlstra@chello.nl
To: fweisbec@gmail.com
To: will.deacon@arm.com
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: wuzhangjin@gmail.com
Cc: paulus@samba.org
Cc: mingo@elte.hu
Cc: acme@redhat.com
Cc: dengcheng.zhu@gmail.com
Cc: matt@console-pimps.org
Cc: sshtylyov@mvista.com
Cc: ddaney@caviumnetworks.com
Patchwork: http://patchwork.linux-mips.org/patch/2012/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This is the MIPS part of the following commit by Peter Zijlstra:

- e360adbe
    irq_work: Add generic hardirq context callbacks

    Provide a mechanism that allows running code in IRQ context. It is
    most useful for NMI code that needs to interact with the rest of the
    system -- like wakeup a task to drain buffers.

    Perf currently has such a mechanism, so extract that and provide it as
    a generic feature, independent of perf so that others may also
    benefit.

    The IRQ context callback is generated through self-IPIs where
    possible, or on architectures like powerpc the decrementer (the
    built-in timer facility) is set to generate an interrupt immediately.

    Architectures that don't have anything like this get to do with a
    callback from the timer tick. These architectures can call
    irq_work_run() at the tail of any IRQ handlers that might enqueue such
    work (like the perf IRQ handler) to avoid undue latencies in
    processing the work.

For MIPSXX, we need to call irq_work_run() at the tail of the perf IRQ
handler as described above.
Reported-by: NWu Zhangjin <wuzhangjin@gmail.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: NDeng-Cheng Zhu <dengcheng.zhu@gmail.com>
To: fweisbec@gmail.com
To: will.deacon@arm.com
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: paulus@samba.org
Cc: mingo@elte.hu
Cc: acme@redhat.com
Cc: matt@console-pimps.org
Cc: sshtylyov@mvista.com,
Patchwork: http://patchwork.linux-mips.org/patch/2011/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NYoichi Yuasa <yuasa@linux-mips.org>
Cc: linux-mips <linux-mips@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/2055/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This error was reported by cppcheck:
arch/mips/loongson/common/machtype.c:56: error: Dangerous usage of 'str' (strncpy doesn't always 0-terminate it)

If strncpy copied MACHTYPE_LEN bytes, the destination string str
was not terminated.

The patch adds one more byte to str and makes sure that this byte is
always 0.
Signed-off-by: NStefan Weil <weil@mail.berlios.de>
Cc: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: Arnaud Patard <apatard@mandriva.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/2053/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Under some combinations of CONFIG_*, lastpfn in page_is_ram is 'set
but not used'.  Mark it as __maybe_unused to quiet the warning/error.
Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2033/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

GCC-4.6 can find more unused code than previous versions could.

In the case of arch/mips/math-emu/ieee754int.h, the COMPXSP and
COMPXDP macros are used in several places, but a couple of them leave
xs unused.  The easiest thing to do is mark it as __maybe_unused to
quiet the warning.
Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2032/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The variable arg3 in _sys_sysmips() is unused.  Remove it.
Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2034/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

GCC-4.6 can find more unused code than previous versions could.

In the case of protected_restore_fp_context{,32}, the variable tmp is
really used.  Its use is tricky in that we really care about the side
effects of the __put_user() calls.  So we must mark tmp with
__maybe_unused to quiet the warning.
Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2035/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NAnoop P A <anoop.pa@gmail.com>
To: Ben Hutchings <ben@decadent.org.uk>
To: linux-mips@linux-mips.org
To: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1804/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NAnoop P A <anoop.pa@gmail.com>
To: linux-mips@linux-mips.org
To: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1803/Tested-by: NShane McDonald <mcdonald.shane@gmail.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Loongson builds have an ad-hoc cmdline default of "console=ttyS0,115200
root=/dev/hda1". These settings come from a vendor; I remember builds
from Lemote branch requiring a "console=tty" override in order to get a
working console.

At least on Yeeloong, they're particularly useless: there's no external
serial port, and the IDE drive is now recognised as /dev/sda.
Signed-off-by: NRobert Millan <rmh@gnu.org>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1759/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The sysmips(MIPS_FIXADE, ...) case contains an obvious copy-and-paste
error in the handling of the TIF_LOGADE flag. Fix that

Patchwork: https://patchwork.linux-mips.org/patch/1997/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

It was reported that GCC-4.3.3 (with CodeSourcery extensions) fails
without this.
Reported-by: NJonas Gorski <jonas.gorski@gmail.com>
Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2010/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

trace.func should be set to the recorded ip of the mcount calling site
in the __mcount_loc section to filter the function entries configured
through the tracing/set_graph_function interface, but before, this is
set to the self_ra(the return address of mcount), which has made
set_graph_function not work as expected.

This fixes it via calculating the right recorded ip in the __mcount_loc
section and assign it to trace.func.
Reported-by: NZhiping Zhong <xzhong86@163.com>
Signed-off-by: NWu Zhangjin <wuzhangjin@gmail.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Sergei Shtylyov <sshtylyov@mvista.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2017/Signed-off-by: NRalf Baechle <ralf@duck.linux-mips.net>

This moves the comments out of ftrace_make_nop() and cleans it.  At the
same time, a macro MCOUNT_OFFSET_INSNS is defined for sharing with the
next patch.
Signed-off-by: NWu Zhangjin <wuzhangjin@gmail.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2008/Signed-off-by: NRalf Baechle <ralf@duck.linux-mips.net>