linux-stable.git/tools/arch/powerpc/include, branch v4.20.2

tools headers: Sync the various kvm.h header copies

2018-10-31T12:57:53+00:00

For powerpc, s390, x86 and the main uapi linux/kvm.h header, none of
them entail changes in tooling.

Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: https://lkml.kernel.org/n/tip-avn7iy8f4tcm2y40sbsdk31m@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

tools, perf: add and use optimized ring_buffer_{read_head, write_tail} helpers

2018-10-19T20:43:08+00:00

Currently, on x86-64, perf uses LFENCE and MFENCE (rmb() and mb(),
respectively) when processing events from the perf ring buffer which
is unnecessarily expensive as we can do more lightweight in particular
given this is critical fast-path in perf.

According to Peter rmb()/mb() were added back then via a94d342b9cb0
("tools/perf: Add required memory barriers") at a time where kernel
still supported chips that needed it, but nowadays support for these
has been ditched completely, therefore we can fix them up as well.

While for x86-64, replacing rmb() and mb() with smp_*() variants would
result in just a compiler barrier for the former and LOCK + ADD for
the latter (__sync_synchronize() uses slower MFENCE by the way), Peter
suggested we can use smp_{load_acquire,store_release}() instead for
architectures where its implementation doesn't resolve in slower smp_mb().
Thus, e.g. in x86-64 we would be able to avoid CPU barrier entirely due
to TSO. For architectures where the latter needs to use smp_mb() e.g.
on arm, we stick to cheaper smp_rmb() variant for fetching the head.

This work adds helpers ring_buffer_read_head() and ring_buffer_write_tail()
for tools infrastructure that either switches to smp_load_acquire() for
architectures where it is cheaper or uses READ_ONCE() + smp_rmb() barrier
for those where it's not in order to fetch the data_head from the perf
control page, and it uses smp_store_release() to write the data_tail.
Latter is smp_mb() + WRITE_ONCE() combination or a cheaper variant if
architecture allows for it. Those that rely on smp_rmb() and smp_mb() can
further improve performance in a follow up step by implementing the two
under tools/arch/*/include/asm/barrier.h such that they don't have to
fallback to rmb() and mb() in tools/include/asm/barrier.h.

Switch perf to use ring_buffer_read_head() and ring_buffer_write_tail()
so it can make use of the optimizations. Later, we convert libbpf as
well to use the same helpers.

Side note [0]: the topic has been raised of whether one could simply use
the C11 gcc builtins [1] for the smp_load_acquire() and smp_store_release()
instead:

  __atomic_load_n(ptr, __ATOMIC_ACQUIRE);
  __atomic_store_n(ptr, val, __ATOMIC_RELEASE);

Kernel and (presumably) tooling shipped along with the kernel has a
minimum requirement of being able to build with gcc-4.6 and the latter
does not have C11 builtins. While generally the C11 memory models don't
align with the kernel's, the C11 load-acquire and store-release alone
/could/ suffice, however. Issue is that this is implementation dependent
on how the load-acquire and store-release is done by the compiler and
the mapping of supported compilers must align to be compatible with the
kernel's implementation, and thus needs to be verified/tracked on a
case by case basis whether they match (unless an architecture uses them
also from kernel side). The implementations for smp_load_acquire() and
smp_store_release() in this patch have been adapted from the kernel side
ones to have a concrete and compatible mapping in place.

  [0] http://patchwork.ozlabs.org/patch/985422/
  [1] https://gcc.gnu.org/onlinedocs/gcc/_005f_005fatomic-Builtins.html

Signed-off-by: Daniel Borkmann 
Acked-by: Peter Zijlstra (Intel) 
Cc: "Paul E. McKenney" 
Cc: Will Deacon 
Cc: Arnaldo Carvalho de Melo 
Signed-off-by: Alexei Starovoitov

tools headers powerpc: Update asm/unistd.h copy to pick new

2018-07-30T14:51:13+00:00

The new 'io_pgetevents' syscall was wired up in PowerPC in the following
cset:

  b2f82565f2ca ("powerpc: Wire up io_pgetevents")

Update tools/arch/powerpc/ copy of the asm/unistd.h file so that 'perf
trace' on PowerPC gets it in its syscall table.

This elliminated the following perf build warning:

  Warning: Kernel ABI header at 'tools/arch/powerpc/include/uapi/asm/unistd.h' differs from latest version at 'arch/powerpc/include/uapi/asm/unistd.h'

Cc: Alexander Shishkin 
Cc: Breno Leitao 
Cc: Hendrik Brueckner 
Cc: Jiri Olsa 
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Michael Ellerman 
Cc: Namhyung Kim 
Cc: Ravi Bangoria 
Cc: Thomas Richter 
Link: https://lkml.kernel.org/n/tip-9uvu7tz4ud3bxxfyxwryuz47@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

tools/headers: Pick up latest kernel ABIs

2018-06-26T06:43:14+00:00

Sync KVM ABI additions and x86 CPU features additions - neither of which
has any impact on the tooling build.

Cc: Arnaldo Carvalho de Melo 
Cc: Peter Zijlstra 
Cc: Namhyung Kim 
Cc: Jiri Olsa 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

tools include powerpc: Update arch/powerpc/include/uapi/asm/unistd.h copy to get 'rseq' syscall

2018-06-25T14:59:36+00:00

This updates the tools/perf/ copy of the powerpc file used to generate
the syscall table file used to make 'perf trace' become aware of the new
'rseq' syscall, no matter in which system it gets built, i.e. older
systems where the syscalls are not available in the running kernel (via
tracefs) or in the system headers will still be aware of these
syscalls/.

From this commit:

  bb862b021d75 ("powerpc: Wire up restartable sequences system call")

Silencing this tools/perf build warning:

  Warning: Kernel ABI header at 'tools/arch/powerpc/include/uapi/asm/unistd.h' differs from latest version at 'arch/powerpc/include/uapi/asm/unistd.h'

Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Boqun Feng 
Cc: David Ahern 
Cc: Hendrik Brueckner 
Cc: Jiri Olsa 
Cc: Mathieu Desnoyers 
Cc: Michael Ellerman 
Cc: Namhyung Kim 
Cc: Ravi Bangoria 
Cc: Thomas Gleixner 
Cc: Thomas Richter 
Cc: Wang Nan 
Link: https://lkml.kernel.org/n/tip-adtgz6u3apd76tghiu9w0k19@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

tools include powerpc: Grab a copy of arch/powerpc/include/uapi/asm/unistd.h

2018-02-16T17:55:47+00:00

Will be used for generating the syscall id/string translation table.

Committer notes:

Update it already to catch with these csets applied since Ravi first
submitted this patch:

  3350eb2ea127 powerpc: sys_pkey_mprotect() system call
  9499ec1b5e82 powerpc: sys_pkey_alloc() and sys_pkey_free() system calls

So now 'perf trace' on ppc now knows about the pkey_ syscals.

Signed-off-by: Ravi Bangoria 
Cc: Alexander Shishkin 
Cc: Hendrik Brueckner 
Cc: Jiri Olsa 
Cc: Michael Ellerman 
Cc: Namhyung Kim 
Cc: Thomas Richter 
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20180129083417.31240-2-ravi.bangoria@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo

tools/headers: Synchronize kernel ABI headers, v4.16-rc1

2018-02-15T13:01:46+00:00

Sync the following tooling headers with the latest kernel version:

  tools/arch/powerpc/include/uapi/asm/kvm.h
  tools/arch/x86/include/asm/cpufeatures.h
  tools/include/uapi/drm/i915_drm.h
  tools/include/uapi/linux/if_link.h
  tools/include/uapi/linux/kvm.h

All the changes are new ABI additions which don't impact their use
in existing tooling.

Cc: Arnaldo Carvalho de Melo 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Namhyung Kim 
Cc: Jiri Olsa 
Cc: Stephen Rothwell 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

tools headers: Sync {tools/,}arch/powerpc/include/uapi/asm/kvm.h

2018-02-02T20:04:53+00:00

The changes in the 3214d01f139b ("KVM: PPC: Book3S: Provide information
about hardware/firmware CVE workarounds") commit right now will not
produce any change in the tools, but that is because we still need to
improve tools/perf/trace/beauty/kvm_ioctl.sh to build per arch string
tables, so that we avoid assigning multiple times to the same command
string entry, i.e. multiple defines, for different arches, have the same
value, causing this:

  In file included from trace/beauty/ioctl.c:82:0:
  /tmp/build/perf/trace/beauty/generated/ioctl/kvm_ioctl_array.c: In function ‘ioctl__scnprintf_kvm_cmd’:
  /tmp/build/perf/trace/beauty/generated/ioctl/kvm_ioctl_array.c:76:11: error: initialized field overwritten [-Werror=override-init]
  /tmp/build/perf/trace/beauty/generated/ioctl/kvm_ioctl_array.c:88:11: note: (near initialization for ‘kvm_ioctl_cmds[165]’)
  /tmp/build/perf/trace/beauty/generated/ioctl/kvm_ioctl_array.c:90:11: error: initialized field overwritten [-Werror=override-init]
    [0xa6] = "PPC_GET_SMMU_INFO",
             ^~~~~~~~~~~~~~~~~~~

So the onlye effect of updating the tools/ copy of ppc's kvm.h header
is to silence these perf build warnings:

  Warning: Kernel ABI header at 'tools/include/uapi/linux/kvm.h' differs from latest version at 'include/uapi/linux/kvm.h'
  Warning: Kernel ABI header at 'tools/arch/powerpc/include/uapi/asm/kvm.h' differs from latest version at 'arch/powerpc/include/uapi/asm/kvm.h'

At some point we should do what we did for the errno tables and create
per-arch string translation tables for the KVM ioctl commands for the
architectures supporting KVM, such as s/390, PowerPC, x86_64 and ARM.

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Hendrik Brueckner 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Paul Mackerras 
Cc: Ravi Bangoria 
Cc: Thomas Richter 
Cc: Wang Nan 
Link: https://lkml.kernel.org/n/tip-jmcf78tqiudgn46zqfw2tgt2@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

tools include arch: Grab a copy of errno.h for arch's supported by perf

2018-01-23T12:51:37+00:00

For each arch in tools/perf/arch, grab a copy of errno.h.

This is a pre-req to generate an architecture specific mapping of errno
numbers to their names.  This errno mapping can be used by perf trace to
support cross-architecture trace reports and to get rid of the
audit-libs dependency.

Signed-off-by: Hendrik Brueckner 
Reviewed-by: Thomas Richter 
Cc: Jiri Olsa 
Cc: Michael Petlan 
Cc: linux-s390@vger.kernel.org
LPU-Reference: 1516352177-11106-2-git-send-email-brueckner@linux.vnet.ibm.com
Link: https://lkml.kernel.org/n/tip-73azjhrzpjsskwi129020i2u@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

License cleanup: add SPDX license identifier to uapi header files with a license

2017-11-02T10:20:11+00:00

Many user space API headers have licensing information, which is either
incomplete, badly formatted or just a shorthand for referring to the
license under which the file is supposed to be.  This makes it hard for
compliance tools to determine the correct license.

Update these files with an SPDX license identifier.  The identifier was
chosen based on the license information in the file.

GPL/LGPL licensed headers get the matching GPL/LGPL SPDX license
identifier with the added 'WITH Linux-syscall-note' exception, which is
the officially assigned exception identifier for the kernel syscall
exception:

   NOTE! This copyright does *not* cover user programs that use kernel
   services by normal system calls - this is merely considered normal use
   of the kernel, and does *not* fall under the heading of "derived work".

This exception makes it possible to include GPL headers into non GPL
code, without confusing license compliance tools.

Headers which have either explicit dual licensing or are just licensed
under a non GPL license are updated with the corresponding SPDX
identifier and the GPLv2 with syscall exception identifier.  The format
is:
        ((GPL-2.0 WITH Linux-syscall-note) OR SPDX-ID-OF-OTHER-LICENSE)

SPDX license identifiers are a legally binding shorthand, which can be
used instead of the full boiler plate text.  The update does not remove
existing license information as this has to be done on a case by case
basis and the copyright holders might have to be consulted. This will
happen in a separate step.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.  See the previous patch in this series for the
methodology of how this patch was researched.

Reviewed-by: Kate Stewart 
Reviewed-by: Philippe Ombredanne 
Reviewed-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman