bwlp/qemu.git/docs/atomics.txt, branch spice_video_codecs

docs: create config/, devel/ and spin/ subdirectories

2017-06-07T16:22:03+00:00

Developer documentation should be its own manual. As a start, move all developer-oriented files to a separate directory. Also move non-text files to their own directories: docs/config/ for QEMU -readconfig input, and docs/spin/ for formal models to be used with the SPIN model checker. Reviewed-by: Daniel P. Berrange Signed-off-by: Paolo Bonzini

atomic: base mb_read/mb_set on load-acquire and store-release

2016-10-24T13:27:15+00:00

This introduces load-acquire and store-release operations in QEMU. For now, just use them as an implementation detail of atomic_mb_read and atomic_mb_set. Since docs/atomics.txt documents that atomic_mb_read only synchronizes with an atomic_mb_set of the same variable, we can use the new implementation everywhere instead of seq-cst loads and stores. Signed-off-by: Paolo Bonzini

atomic: introduce smp_mb_acquire and smp_mb_release

2016-10-24T09:30:55+00:00

Signed-off-by: Paolo Bonzini

docs/atomics: update comparison with Linux

2016-05-29T07:11:11+00:00

Over time, some differences between QEMU and Linux atomics are getting smoothed. In particular, Linux grew atomic_fetch_or (and in general the differences regarding RMW operations were not described accurately) and smp_load_acquire/smp_store_release. Also, set_mb was renamed to smp_store_mb(). Include these changes in the documentation. Signed-off-by: Paolo Bonzini

docs/atomics: update atomic_read/set comparison with Linux

2016-05-29T07:11:11+00:00

Recently Linux did a mass conversion of its atomic_read/set calls so that they at least are READ/WRITE_ONCE. See Linux's commit 62e8a325 ("atomic, arch: Audit atomic_{read,set}()"). It seems though that their documentation hasn't been updated to reflect this. The appended updates our documentation to reflect the change, which means there is effectively no difference between our atomic_read/set and the current Linux implementation. While at it, fix the statement that a barrier is implied by atomic_read/set, which is incorrect. Volatile/atomic semantics prevent transformations pertaining the variable they apply to; this, however, has no effect on surrounding statements like barriers do. For more details on this, see: https://gcc.gnu.org/onlinedocs/gcc/Volatiles.html Signed-off-by: Emilio G. Cota Message-Id: <1464120374-8950-2-git-send-email-cota@braap.org> Signed-off-by: Paolo Bonzini

docs/atomics.txt: Update pointer to linux macro

2016-05-23T14:53:43+00:00

Add a missing end brace and update doc to point to the latest access macro. ACCESS_ONCE() is deprecated. Signed-off-by: Pranith Kumar Message-Id: <1462198852-28694-1-git-send-email-bobby.prani@gmail.com> Signed-off-by: Paolo Bonzini

docs/atomics.txt: fix two typos

2015-04-30T13:05:48+00:00

Cc: Paolo Bonzini Signed-off-by: Laszlo Ersek Signed-off-by: Michael Tokarev

add a header file for atomic operations

2013-07-04T15:42:49+00:00

We're already using them in several places, but __sync builtins are just too ugly to type, and do not provide seqcst load/store operations. Reviewed-by: Richard Henderson Signed-off-by: Paolo Bonzini