Commit Graph

13 Commits

Author SHA1 Message Date
Mathieu Desnoyers 41806ef4bf [POWERPC] atomic.h: Add atomic64 cmpxchg, xchg and add_unless to powerpc
atomic.h : Add atomic64 cmpxchg, xchg and add_unless to powerpc

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-02-16 14:00:20 +11:00
Robert Jennings 434f98c48f [POWERPC] atomic_dec_if_positive sign extension fix
On 64-bit machines, if an atomic counter is explicitly set to a
negative value, the atomic_dec_if_positive function will decrement and
store the next smallest value in the atomic counter, contrary to its
intended operation.

The comparison to determine if the decrement will make the result
negative was done by the "addic." instruction, which operates on a
64-bit value, namely the zero-extended word loaded from the atomic
variable.  This patch uses an explicit word compare (cmpwi) and
changes the addic. to an addi (also changing "=&r" to "=&b" so that r0
isn't used, and addi doesn't become li).

This also fixes a bug for both 32-bit and 64-bit in that previously
0x80000000 was considered positive, since the result after
decrementing is positive.  Now it is considered negative.

Also, I clarify the return value in the comments just to make it clear
that the value returned is always the decremented value, even if that
value is not stored back to the atomic counter.

Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-01-22 21:27:36 +11:00
Linus Torvalds e2a3d40258 power: improve inline asm memory constraints
Use "+m" rather than a combination of "=m" and "m" for improved
clarity and consistency.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-08 15:00:28 -07:00
Nick Piggin f055affb89 [PATCH] powerpc: native atomic_add_unless
Do atomic_add_unless natively instead of using cmpxchg.
Improved register allocation idea from Joel Schopp.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-24 14:06:02 +11:00
Anton Blanchard b11fa580ac [PATCH] powerpc: reformat atomic_add_unless
It makes my eyes hurt.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-13 21:18:54 +11:00
Anton Blanchard 144b9c135b [PATCH] powerpc: use lwsync in atomics, bitops, lock functions
eieio is only a store - store ordering. When used to order an unlock
operation loads may leak out of the critical region. This is potentially
buggy, one example is if a user wants to atomically read a couple of
values.

We can solve this with an lwsync which orders everything except store - load.

I removed the (now unused) EIEIO_ON_SMP macros and the c versions
isync_on_smp and eieio_on_smp now we dont use them. I also removed some
old comments that were used to identify inline spinlocks in assembly,
they dont make sense now our locks are out of line.

Another interesting thing was that read_unlock was using an eieio even
though the rest of the spinlock code had already been converted to
use lwsync.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-13 21:18:50 +11:00
Ingo Molnar ffbf670f5c [PATCH] mutex subsystem, add atomic_xchg() to all arches
add atomic_xchg() to all the architectures. Needed by the new mutex code.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
2006-01-09 15:59:17 -08:00
Christoph Lameter d3cb487149 [PATCH] atomic_long_t & include/asm-generic/atomic.h V2
Several counters already have the need to use 64 atomic variables on 64 bit
platforms (see mm_counter_t in sched.h).  We have to do ugly ifdefs to fall
back to 32 bit atomic on 32 bit platforms.

The VM statistics patch that I am working on will also make more extensive
use of atomic64.

This patch introduces a new type atomic_long_t by providing definitions in
asm-generic/atomic.h that works similar to the c "long" type.  Its 32 bits
on 32 bit platforms and 64 bits on 64 bit platforms.

Also cleans up the determination of the mm_counter_t in sched.h.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:33:29 -08:00
Nick Piggin 8426e1f6af [PATCH] atomic: inc_not_zero
Introduce an atomic_inc_not_zero operation.  Make this a special case of
atomic_add_unless because lockless pagecache actually wants
atomic_inc_not_negativeone due to its offset refcount.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-13 18:14:16 -08:00
Nick Piggin 4a6dae6d38 [PATCH] atomic: cmpxchg
Introduce an atomic_cmpxchg operation.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-13 18:14:16 -08:00
Stephen Rothwell 06a98dba0d powerpc: implement atomic64_t on ppc64
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
2005-11-10 15:51:14 +11:00
David Gibson 3ddfbcf19b [PATCH] powerpc: Consolidate asm compatibility macros
This patch consolidates macros used to generate assembly for
compatibility across different CPUs or configs.  A new header,
asm-powerpc/asm-compat.h contains the main compatibility macros.  It
uses some preprocessor magic to make the macros suitable both for use
in .S files, and in inline asm in .c files.  Headers (bitops.h,
uaccess.h, atomic.h, bug.h) which had their own such compatibility
macros are changed to use asm-compat.h.

ppc_asm.h is now for use in .S files *only*, and a #error enforces
that.  As such, we're a lot more careless about namespace pollution
here than in asm-compat.h.

While we're at it, this patch adds a call to the PPC405_ERR77 macro in
futex.h which should have had it already, but didn't.

Built and booted on pSeries, Maple and iSeries (ARCH=powerpc).  Built
for 32-bit powermac (ARCH=powerpc) and Walnut (ARCH=ppc).

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-11-10 13:10:38 +11:00
Becky Bruce feaf7cf153 [PATCH] powerpc: merge atomic.h, memory.h
powerpc: Merge atomic.h and memory.h into powerpc

Merged atomic.h into include/powerpc.  Moved asm-style HMT_ defines from
memory.h into ppc_asm.h, where there were already HMT_defines; moved c-style
HMT_ defines to processor.h. Renamed memory.h to synch.h to better reflect
its contents.

Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
Signed-off-by: Becky Bruce <becky.bruce@freescale.com>
Signed-off-by: Jon Loeliger <linuxppc@jdl.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-25 22:38:46 +10:00