This is added based on the fact that this is an iforce-based device and
that the Windows driver for the R440 works for the Logitech WingMan Formula
Force after replacing the device/vendor IDs.
Signed-off-by: Tim Schumacher <timschumi@gmx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Instead of open-coding conversion from/to little-endian, let's
use proper accessors.
Tested-by: Tim Schumacher <timschumi@gmx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Transport initialization code now deals mostly with transport-specific
data, so we can drop couple of temporary variables.
Tested-by: Tim Schumacher <timschumi@gmx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

It is not needed anymore as behavior is controlled by the transport
operations set up for given device.
Tested-by: Tim Schumacher <timschumi@gmx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

USB transport has to use cache line-aligned buffers for transfers to avoid
DMA issues; serio doe snot have such restrictions. Let's move "data_in"
buffer from main driver structure into transport modules and make sure USB
requirements are respected.
Tested-by: Tim Schumacher <timschumi@gmx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

We want to move buffer handling into transport layers as the properties of
buffers (DMA-safety, alignment, etc) are different for different
transports. To allow this, let's allow caller to specify their own buffers
for the results of iforce_get_id_packet() and let transport drivers to
figure what buffers they need to use for transfers.
Tested-by: Tim Schumacher <timschumi@gmx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

It is excessive to check if device is fully initialized in
iforce_process_packet(), as for USB-conected devices we do not start
collecting reports until the device is fully initialized.

Let's change serio transport code to not call iforce_process_packet()
until device initialization is done.
Tested-by: Tim Schumacher <timschumi@gmx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Signalling command completion from iforce_process_packet() does
not make sense, as not all transport use the same data path for
both commands and motion data form the device, that is why USB
code already has to signal command completion iforce_usb_out().

Let's move signalling completion into individual transport
modules.
Tested-by: Tim Schumacher <timschumi@gmx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Current code combines packet type and data length into single argument to
iforce_process_packet() and then has to untangle it. It is much clearer to
simply use separate arguments.
Tested-by: Tim Schumacher <timschumi@gmx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

This makes code clearer a bit.
Tested-by: Tim Schumacher <timschumi@gmx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

According to our coding style case labels in switch statements should
be aligned with the switch keyword.
Tested-by: Tim Schumacher <timschumi@gmx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

When working with USB devices we need to use DMA-safe buffers,
and iforce->edata is not one. Let's rework the code to allocate
temporary buffer (iforce_get_id() is called only during initialization
so there is no reason to have permanent buffer) and use it. While at it,
let's utilize usb_control_msg() API which simplifies code.
Tested-by: Tim Schumacher <timschumi@gmx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Now that we have moved enough transport details into separate source files
we can change them into transport modules so that they are only loaded when
needed.
Tested-by: Tim Schumacher <timschumi@gmx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

This moves transport-specific data from main iforce structure into
transport modules.
Tested-by: Tim Schumacher <timschumi@gmx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Note that the parent device for the USB-connected controllers is now
USB interface instead of USB device.
Tested-by: Tim Schumacher <timschumi@gmx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Add start_io() and stop_io() transport methods so that core
does not have to know the details.
Tested-by: Tim Schumacher <timschumi@gmx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Continue teasing apart protocol-specific bits from core into transport
modules. This time move RS232-specific command completion handling
from core to iforce-serio module.
Tested-by: Tim Schumacher <timschumi@gmx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

To avoid #ifdef-ing out parts of the code and having conditionals in normal
control flow, let's define "get_id" transport method and move
implementation into respective transport modules.
Tested-by: Tim Schumacher <timschumi@gmx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

In order to tease apart the driver into core and transport modules, let's
introduce transport operations and make "xmit" the very first one such
operation.
Tested-by: Tim Schumacher <timschumi@gmx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

The kernel is supposed to handle multiple devices, static flags
in packet handling code will never work.
Tested-by: Tim Schumacher <timschumi@gmx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Pull perf fixes from Ingo Molnar:
 "I'd like to apologize for this very late pull request: I was dithering
  through the week whether to send the fixes, and then yesterday Jiri's
  crash fix for a regression introduced in this cycle clearly marked
  perf/urgent as 'must merge now'.

  Most of the commits are tooling fixes, plus there's three kernel fixes
  via four commits:

    - race fix in the Intel PEBS code

    - fix an AUX bug and roll back a previous attempt

    - fix AMD family 17h generic HW cache-event perf counters

  The largest diffstat contribution comes from the AMD fix - a new event
  table is introduced, which is a fairly low risk change but has a large
  linecount"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel: Fix race in intel_pmu_disable_event()
  perf/x86/intel/pt: Remove software double buffering PMU capability
  perf/ring_buffer: Fix AUX software double buffering
  perf tools: Remove needless asm/unistd.h include fixing build in some places
  tools arch uapi: Copy missing unistd.h headers for arc, hexagon and riscv
  tools build: Add -ldl to the disassembler-four-args feature test
  perf cs-etm: Always allocate memory for cs_etm_queue::prev_packet
  perf cs-etm: Don't check cs_etm_queue::prev_packet validity
  perf report: Report OOM in status line in the GTK UI
  perf bench numa: Add define for RUSAGE_THREAD if not present
  tools lib traceevent: Change tag string for error
  perf annotate: Fix build on 32 bit for BPF annotation
  tools uapi x86: Sync vmx.h with the kernel
  perf bpf: Return value with unlocking in perf_env__find_btf()
  MAINTAINERS: Include vendor specific files under arch/*/events/*
  perf/x86/amd: Update generic hardware cache events for Family 17h

Pull scheduler fix from Ingo Molnar:
 "Fix a kobject memory leak in the cpufreq code"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/cpufreq: Fix kobject memleak

Pull x86 fix from Ingo Molnar:
 "Disable function tracing during early SME setup to fix a boot crash on
  SME-enabled kernels running distro kernels (some of which have
  function tracing enabled)"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm/mem_encrypt: Disable all instrumentation for early SME setup

Pull vfs fixes from Al Viro:

 - a couple of ->i_link use-after-free fixes

 - regression fix for wrong errno on absent device name in mount(2)
   (this cycle stuff)

 - ancient UFS braino in large GID handling on Solaris UFS images (bogus
   cut'n'paste from large UID handling; wrong field checked to decide
   whether we should look at old (16bit) or new (32bit) field)

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  ufs: fix braino in ufs_get_inode_gid() for solaris UFS flavour
  Abort file_remove_privs() for non-reg. files
  [fix] get rid of checking for absent device name in vfs_get_tree()
  apparmorfs: fix use-after-free on symlink traversal
  securityfs: fix use-after-free on symlink traversal

New race in x86_pmu_stop() was introduced by replacing the
atomic __test_and_clear_bit() of cpuc->active_mask by separate
test_bit() and __clear_bit() calls in the following commit:

  3966c3fe ("x86/perf/amd: Remove need to check "running" bit in NMI handler")

The race causes panic for PEBS events with enabled callchains:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
  ...
  RIP: 0010:perf_prepare_sample+0x8c/0x530
  Call Trace:
   <NMI>
   perf_event_output_forward+0x2a/0x80
   __perf_event_overflow+0x51/0xe0
   handle_pmi_common+0x19e/0x240
   intel_pmu_handle_irq+0xad/0x170
   perf_event_nmi_handler+0x2e/0x50
   nmi_handle+0x69/0x110
   default_do_nmi+0x3e/0x100
   do_nmi+0x11a/0x180
   end_repeat_nmi+0x16/0x1a
  RIP: 0010:native_write_msr+0x6/0x20
  ...
   </NMI>
   intel_pmu_disable_event+0x98/0xf0
   x86_pmu_stop+0x6e/0xb0
   x86_pmu_del+0x46/0x140
   event_sched_out.isra.97+0x7e/0x160
  ...

The event is configured to make samples from PEBS drain code,
but when it's disabled, we'll go through NMI path instead,
where data->callchain will not get allocated and we'll crash:

          x86_pmu_stop
            test_bit(hwc->idx, cpuc->active_mask)
            intel_pmu_disable_event(event)
            {
              ...
              intel_pmu_pebs_disable(event);
              ...

EVENT OVERFLOW ->  <NMI>
                     intel_pmu_handle_irq
                       handle_pmi_common
   TEST PASSES ->        test_bit(bit, cpuc->active_mask))
                           perf_event_overflow
                             perf_prepare_sample
                             {
                               ...
                               if (!(sample_type & __PERF_SAMPLE_CALLCHAIN_EARLY))
                                     data->callchain = perf_callchain(event, regs);

         CRASH ->              size += data->callchain->nr;
                             }
                   </NMI>
              ...
              x86_pmu_disable_event(event)
            }

            __clear_bit(hwc->idx, cpuc->active_mask);

Fixing this by disabling the event itself before setting
off the PEBS bit.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Arcari <darcari@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Lendacky Thomas <Thomas.Lendacky@amd.com>
Cc: Linus Torvalds <torvalds@linux-foundation.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>
Fixes: 3966c3fe ("x86/perf/amd: Remove need to check "running" bit in NMI handler")
Link: http://lkml.kernel.org/r/20190504151556.31031-1-jolsa@kernel.orgSigned-off-by: Ingo Molnar <mingo@kernel.org>

Pull powerpc fix from Michael Ellerman:
 "One regression fix.

  Changes we merged to STRICT_KERNEL_RWX on 32-bit were causing crashes
  under load on some machines depending on memory layout.

  Thanks to Christophe Leroy"

* tag 'powerpc-5.1-7' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/32s: Fix BATs setting with CONFIG_STRICT_KERNEL_RWX

Pull KVM fixes from Paolo Bonzini:

 - PPC and ARM bugfixes from submaintainers

 - Fix old Windows versions on AMD (recent regression)

 - Fix old Linux versions on processors without EPT

 - Fixes for LAPIC timer optimizations

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (21 commits)
  KVM: nVMX: Fix size checks in vmx_set_nested_state
  KVM: selftests: make hyperv_cpuid test pass on AMD
  KVM: lapic: Check for in-kernel LAPIC before deferencing apic pointer
  KVM: fix KVM_CLEAR_DIRTY_LOG for memory slots of unaligned size
  x86/kvm/mmu: reset MMU context when 32-bit guest switches PAE
  KVM: x86: Whitelist port 0x7e for pre-incrementing %rip
  Documentation: kvm: fix dirty log ioctl arch lists
  KVM: VMX: Move RSB stuffing to before the first RET after VM-Exit
  KVM: arm/arm64: Don't emulate virtual timers on userspace ioctls
  kvm: arm: Skip stage2 huge mappings for unaligned ipa backed by THP
  KVM: arm/arm64: Ensure vcpu target is unset on reset failure
  KVM: lapic: Convert guest TSC to host time domain if necessary
  KVM: lapic: Allow user to disable adaptive tuning of timer advancement
  KVM: lapic: Track lapic timer advance per vCPU
  KVM: lapic: Disable timer advancement if adaptive tuning goes haywire
  x86: kvm: hyper-v: deal with buggy TLB flush requests from WS2012
  KVM: x86: Consider LAPIC TSC-Deadline timer expired if deadline too short
  KVM: PPC: Book3S: Protect memslots while validating user address
  KVM: PPC: Book3S HV: Perserve PSSCR FAKE_SUSPEND bit on guest exit
  KVM: arm/arm64: vgic-v3: Retire pending interrupts on disabling LPIs
  ...

Merge branch 'i2c/for-current-fixed' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c fixes from Wolfram Sang:
 "I2C driver bugfixes and a MAINTAINERS update for you"

* 'i2c/for-current-fixed' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: Prevent runtime suspend of adapter when Host Notify is required
  i2c: synquacer: fix enumeration of slave devices
  MAINTAINERS: friendly takeover of i2c-gpio driver
  i2c: designware: ratelimit 'transfer when suspended' errors
  i2c: imx: correct the method of getting private data in notifier_call

Pull drm fix from Dave Airlie:
 "Just a single qxl revert"

* tag 'drm-fixes-2019-05-03' of git://anongit.freedesktop.org/drm/drm:
  Revert "drm/qxl: drop prime import/export callbacks"

Pull clk fixes from Stephen Boyd:
 "Two fixes for the NKMP clks on Allwinner SoCs, a locking fix for
  clkdev where we forgot to hold a lock while iterating a list that can
  change, and finally a build fix that adds some stubs for clk APIs that
  are used by devfreq drivers on platforms without the clk APIs"

* tag 'clk-fixes-for-linus' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk: Add missing stubs for a few functions
  clkdev: Hold clocks_mutex while iterating clocks list
  clk: sunxi-ng: nkmp: Explain why zero width check is needed
  clk: sunxi-ng: nkmp: Avoid GENMASK(-1, 0)

Pull sound fixes from Takashi Iwai:
 "A few stable fixes at this round.

  The USB Line6 audio fixes are a bit large, but they are rather trivial
  and pretty much device-specific, so should be safe to apply at this
  late stage. Ditto for other HD-audio quirks"

* tag 'sound-5.1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda/realtek - Apply the fixup for ASUS Q325UAR
  ALSA: line6: use dynamic buffers
  ALSA: hda/realtek - Fixed Dell AIO speaker noise
  ALSA: hda/realtek - Add new Dell platform for headset mode

Now that all AUX allocations are high-order by default, the software
double buffering PMU capability doesn't make sense any more, get rid
of it. In case some PMUs choose to opt out, we can re-introduce it.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: adrian.hunter@intel.com
Link: http://lkml.kernel.org/r/20190503085536.24119-3-alexander.shishkin@linux.intel.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

This recent commit:

  5768402f ("perf/ring_buffer: Use high order allocations for AUX buffers optimistically")

overlooked the fact that the previous one page granularity of the AUX buffer
provided an implicit double buffering capability to the PMU driver, which
went away when the entire buffer became one high-order page.

Always make the full-trace mode AUX allocation at least two-part to preserve
the previous behavior and allow the implicit double buffering to continue.
Reported-by: Ammy Yi <ammy.yi@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: adrian.hunter@intel.com
Fixes: 5768402f ("perf/ring_buffer: Use high order allocations for AUX buffers optimistically")
Link: http://lkml.kernel.org/r/20190503085536.24119-2-alexander.shishkin@linux.intel.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'perf-urgent-for-mingo-5.1-20190502' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull perf/urgent fixes from Arnaldo Carvalho de Melo:

tools UAPI:

  Arnaldo Carvalho de Melo:

  - Sync x86's vmx.h with the kernel.

  - Copy missing unistd.h headers for arc, hexagon and riscv, fixing
    a reported build regression on the ARC 32-bit architecture.

perf bench numa:

  Arnaldo Carvalho de Melo:

  - Add define for RUSAGE_THREAD if not present, fixing the build on the
    ARC architecture when only zlib and libnuma are present.

perf BPF:

  Arnaldo Carvalho de Melo:

  - The disassembler-four-args feature test needs -ldl on distros such as
    Mageia 7.

  Bo YU:

  - Fix unlocking on success in perf_env__find_btf(), detected with
    the coverity tool.

libtraceevent:

  Leo Yan:

  - Change misleading hard coded 'trace-cmd' string in error messages.

ARM hardware tracing:

  Leo Yan:

  - Always allocate memory for cs_etm_queue::prev_packet, fixing a segfault
    when processing CoreSight perf data.

perf annotate:

  Thadeu Lima de Souza Cascardo:

  - Fix build on 32 bit for BPF.

perf report:

  Thomas Richter:

  - Report OOM in status line in the GTK UI.

core libs:

  - Remove needless asm/unistd.h that, used with sys/syscall.h ended
    up redefining the syscalls defines in environments such as the
    ARC arch when using uClibc.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

- One revert for QXL for a DRI3 breakage
Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190502122529.hguztj3kncaixe3d@flea

We were including sys/syscall.h and asm/unistd.h, since sys/syscall.h
includes asm/unistd.h, sometimes this leads to the redefinition of
defines, breaking the build.

Noticed on ARC with uCLibc.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Link: https://lkml.kernel.org/n/tip-xjpf80o64i2ko74aj2jih0qg@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Since those were introduced in:

  c8ce48f0 ("asm-generic: Make time32 syscall numbers optional")

But when the asm-generic/unistd.h was sync'ed with tools/ in:

  1a787fc5 ("tools headers uapi: Sync copy of asm-generic/unistd.h with the kernel sources")

I forgot to copy the files for the architectures that define
__ARCH_WANT_TIME32_SYSCALLS, so the perf build was breaking there, as
reported by Vineet Gupta for the ARC architecture.

After updating my ARC container to use the glibc based toolchain + cross
building libnuma, zlib and elfutils, I finally managed to reproduce the
problem and verify that this now is fixed and will not regress as will
be tested before each pull req sent upstream.
Reported-by: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jiri Olsa <jolsa@kernel.org>
CC: linux-snps-arc@lists.infradead.org
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/r/20190426193531.GC28586@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Thomas Backlund reported that the perf build was failing on the Mageia 7
distro, that is because it uses:

  cat /tmp/build/perf/feature/test-disassembler-four-args.make.output
  /usr/bin/ld: /usr/lib64/libbfd.a(plugin.o): in function `try_load_plugin':
  /home/iurt/rpmbuild/BUILD/binutils-2.32/objs/bfd/../../bfd/plugin.c:243:
  undefined reference to `dlopen'
  /usr/bin/ld:
  /home/iurt/rpmbuild/BUILD/binutils-2.32/objs/bfd/../../bfd/plugin.c:271:
  undefined reference to `dlsym'
  /usr/bin/ld:
  /home/iurt/rpmbuild/BUILD/binutils-2.32/objs/bfd/../../bfd/plugin.c:256:
  undefined reference to `dlclose'
  /usr/bin/ld:
  /home/iurt/rpmbuild/BUILD/binutils-2.32/objs/bfd/../../bfd/plugin.c:246:
  undefined reference to `dlerror'
  as we allow dynamic linking and loading

Mageia 7 uses these linker flags:
  $ rpm --eval %ldflags
    -Wl,--as-needed -Wl,--no-undefined -Wl,-z,relro -Wl,-O1 -Wl,--build-id -Wl,--enable-new-dtags

So add -ldl to this feature LDFLAGS.
Reported-by: Thomas Backlund <tmb@mageia.org>
Tested-by: Thomas Backlund <tmb@mageia.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Link: https://lkml.kernel.org/r/20190501173158.GC21436@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Robert Walker reported a segmentation fault is observed when process
CoreSight trace data; this issue can be easily reproduced by the command
'perf report --itrace=i1000i' for decoding tracing data.

If neither the 'b' flag (synthesize branches events) nor 'l' flag
(synthesize last branch entries) are specified to option '--itrace',
cs_etm_queue::prev_packet will not been initialised.  After merging the
code to support exception packets and sample flags, there introduced a
number of uses of cs_etm_queue::prev_packet without checking whether it
is valid, for these cases any accessing to uninitialised prev_packet
will cause crash.

As cs_etm_queue::prev_packet is used more widely now and it's already
hard to follow which functions have been called in a context where the
validity of cs_etm_queue::prev_packet has been checked, this patch
always allocates memory for cs_etm_queue::prev_packet.
Reported-by: Robert Walker <robert.walker@arm.com>
Suggested-by: Robert Walker <robert.walker@arm.com>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Tested-by: Robert Walker <robert.walker@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Suzuki K Poulouse <suzuki.poulose@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Fixes: 7100b12c ("perf cs-etm: Generate branch sample for exception packet")
Fixes: 24fff5eb ("perf cs-etm: Avoid stale branch samples when flush packet")
Link: http://lkml.kernel.org/r/20190428083228.20246-1-leo.yan@linaro.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>