Commit Graph

5 Commits

Author SHA1 Message Date
Stefano Garzarella 29f2316761 docs: fix references to docs/devel/atomics.rst
Commit 15e8699f00 ("atomics: convert to reStructuredText") converted
docs/devel/atomics.txt to docs/devel/atomics.rst.

We still have several references to the old file, so let's fix them
with the following command:

  sed -i s/atomics.txt/atomics.rst/ $(git grep -l docs/devel/atomics.txt)

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210517151702.109066-3-sgarzare@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2021-06-02 06:51:09 +02:00
Stefan Hajnoczi d73415a315 qemu/atomic.h: rename atomic_ to qatomic_
clang's C11 atomic_fetch_*() functions only take a C11 atomic type
pointer argument. QEMU uses direct types (int, etc) and this causes a
compiler error when a QEMU code calls these functions in a source file
that also included <stdatomic.h> via a system header file:

  $ CC=clang CXX=clang++ ./configure ... && make
  ../util/async.c:79:17: error: address argument to atomic operation must be a pointer to _Atomic type ('unsigned int *' invalid)

Avoid using atomic_*() names in QEMU's atomic.h since that namespace is
used by <stdatomic.h>. Prefix QEMU's APIs with 'q' so that atomic.h
and <stdatomic.h> can co-exist. I checked /usr/include on my machine and
searched GitHub for existing "qatomic_" users but there seem to be none.

This patch was generated using:

  $ git grep -h -o '\<atomic\(64\)\?_[a-z0-9_]\+' include/qemu/atomic.h | \
    sort -u >/tmp/changed_identifiers
  $ for identifier in $(</tmp/changed_identifiers); do
        sed -i "s%\<$identifier\>%q$identifier%g" \
            $(git grep -I -l "\<$identifier\>")
    done

I manually fixed line-wrap issues and misaligned rST tables.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200923105646.47864-1-stefanha@redhat.com>
2020-09-23 16:07:44 +01:00
Markus Armbruster ec150c7e09 include: Make headers more self-contained
Back in 2016, we discussed[1] rules for headers, and these were
generally liked:

1. Have a carefully curated header that's included everywhere first.  We
   got that already thanks to Peter: osdep.h.

2. Headers should normally include everything they need beyond osdep.h.
   If exceptions are needed for some reason, they must be documented in
   the header.  If all that's needed from a header is typedefs, put
   those into qemu/typedefs.h instead of including the header.

3. Cyclic inclusion is forbidden.

This patch gets include/ closer to obeying 2.

It's actually extracted from my "[RFC] Baby steps towards saner
headers" series[2], which demonstrates a possible path towards
checking 2 automatically.  It passes the RFC test there.

[1] Message-ID: <87h9g8j57d.fsf@blackfin.pond.sub.org>
    https://lists.nongnu.org/archive/html/qemu-devel/2016-03/msg03345.html
[2] Message-Id: <20190711122827.18970-1-armbru@redhat.com>
    https://lists.nongnu.org/archive/html/qemu-devel/2019-07/msg02715.html

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-2-armbru@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2019-08-16 13:31:51 +02:00
Catherine Ho 7400d6938c tcg: add early clober modifier in atomic16_cmpxchg on aarch64
Without this patch, gcc might up the Input/Output registers and
cause unpredictable error.

Fixes: 1ec182c333 ("target/arm: Convert to HAVE_CMPXCHG128")

Signed-off-by: Catherine Ho <catherine.hecx@gmail.com>
Message-Id: <1548838794-23757-1-git-send-email-catherine.hecx@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-02-06 03:38:39 +00:00
Richard Henderson e6cd4bb59b tcg: Split CONFIG_ATOMIC128
GCC7+ will no longer advertise support for 16-byte __atomic operations
if only cmpxchg is supported, as for x86_64.  Fortunately, x86_64 still
has support for __sync_compare_and_swap_16 and we can make use of that.
AArch64 does not have, nor ever has had such support, so open-code it.

Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-18 19:46:36 -07:00