[PATCH 0/10] x86-32: improve atomic64_t functions

From: Luca Barbieri
Date: Wed Feb 17 2010 - 06:44:19 EST


This patchset improves the atomic64_t functions on x86-32.
It also includes a testsuite that has been used to test this functionality
and can test any atomic64_t implementation.

It offers the following improvements:
1. Better code due to hand-written assembly (e.g. use of the ZF flag)
2. All atomic64 functions implemented, efficiently
3. Support for 386/486 due to the ability to alternatively use either
the cmpxchg8b based implementation or the generic implementation
4. Use of SSE, if available, for atomic64_read and atomic64_set

The first patches add functionality to the alternatives system to support
the new atomic64_t code.
A patch that improves cmpxchg64() using that functionality is also included.

To test this code, enable CONFIG_ATOMIC64_SELFTEST, compile for 386 and
boot normally, with "clearcpuid=25" and with "clearcpuid=8 clearcpuid=25".

You should receive a message stating that the atomic64 test passed,
along with the selected configuration.

Signed-off-by: Luca Barbieri <luca@xxxxxxxxxxxxxxxxx>

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