On Fri, Apr 25, 2008 at 9:48 AM, Philippe Gerum <[EMAIL PROTECTED]> wrote:
> Gilles Chanteperdrix wrote:
> > This patch implements the _read, _set, and _cmpxchg operations on
> > and atomic_ptr_t in user-space in include/asm-generic/atomic.h which
> should be
> > included at the end of include/asm-*/atomic.h after the definition of the
> > operations for the atomic_t type and atomic64_t type on 64 bits platforms.
> > These operations are the basic operations used by user-space mutexes.
> Maybe we
> > should add the xnarch_ prefix ?
> Yes, but more generally, we should rework this to fit the existing atomic
> support in include/asm-*/atomic.h, so that we don't end up with sideways to
> has been already designed to support set, get, xchg and the like, in both
> and userland context.
That is not exactly sideways... Linux include/asm-generic/atomic.h
defines operations for atomic_long_t. This file adds two things:
- support for atomic_long_t in user-space (where we can not include
- support for a new type atomic_ptr_t both to kernel-space and
user-space, the aim is to avoid all the casts that would take place if
we wanted to use atomic_long_t to store pointers.
However for this file to work, it has to be included by asm-*/atomic.h
after the definition of atomic_t (and atomic64_t on 64 bits
platforms). So linux includes asm-generic/atomic.h at the end of
asm/atomic.h, I simply reproduced this scheme with Xenomai
Xenomai-core mailing list