[PATCH] s390: atomic primitives

      Hugh Dickins <hugh@veritas.com>

Fix the broken atomic_cmpxchg primitive.  Add atomic_sub_and_test,
atomic64_sub_return, atomic64_sub_and_test, atomic64_cmpxchg,
atomic64_add_unless and atomic64_inc_not_zero.  Replace old style
atomic_compare_and_swap by atomic_cmpxchg.  Shorten the whole header by
defining most primitives with the two inline functions atomic_add_return and
atomic_sub_return.

In addition this patch contains the s390 related fixes of Hugh's "mm: fill
arch atomic64 gaps" patch.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 4 insertions, 4 deletions

diff --git a/arch/s390/kernel/machine_kexec.c b/arch/s390/kernel/machine_kexec.c
index 5aa71b05b8ae..f0ed5c642c74 100644
--- a/arch/s390/kernel/machine_kexec.c
+++ b/arch/s390/kernel/machine_kexec.c
@@ -85,7 +85,7 @@ kexec_halt_all_cpus(void *kernel_image)
                 pfault_fini();
 #endif
 
-        if (atomic_compare_and_swap(-1, smp_processor_id(), &cpuid))
+        if (atomic_cmpxchg(&cpuid, -1, smp_processor_id()) != -1)
                 signal_processor(smp_processor_id(), sigp_stop);
 
         /* Wait for all other cpus to enter stopped state */
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 5856b3fda6bf..bd5b311006be 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -263,7 +263,7 @@ static void do_machine_restart(void * __unused)
         int cpu;
         static atomic_t cpuid = ATOMIC_INIT(-1);
 
-        if (atomic_compare_and_swap(-1, smp_processor_id(), &cpuid))
+        if (atomic_cmpxchg(&cpuid, -1, smp_processor_id()) != -1)
                 signal_processor(smp_processor_id(), sigp_stop);
 
         /* Wait for all other cpus to enter stopped state */
@@ -313,7 +313,7 @@ static void do_machine_halt(void * __unused)
 {
         static atomic_t cpuid = ATOMIC_INIT(-1);
 
-        if (atomic_compare_and_swap(-1, smp_processor_id(), &cpuid) == 0) {
+        if (atomic_cmpxchg(&cpuid, -1, smp_processor_id()) == -1) {
                 smp_send_stop();
                 if (MACHINE_IS_VM && strlen(vmhalt_cmd) > 0)
                         cpcmd(vmhalt_cmd, NULL, 0, NULL);
@@ -332,7 +332,7 @@ static void do_machine_power_off(void * __unused)
 {
         static atomic_t cpuid = ATOMIC_INIT(-1);
 
-        if (atomic_compare_and_swap(-1, smp_processor_id(), &cpuid) == 0) {
+        if (atomic_cmpxchg(&cpuid, -1, smp_processor_id()) == -1) {
                 smp_send_stop();
                 if (MACHINE_IS_VM && strlen(vmpoff_cmd) > 0)
                         cpcmd(vmpoff_cmd, NULL, 0, NULL);