[PATCH v8 04/13] this_cpu_cmpxchg: S390: switch this_cpu_cmpxchg to locked, add _local function

Marcelo Tosatti
2023-05-15T18:07:38Z

Goal is to have vmstat_shepherd to transfer from
per-CPU counters to global counters remotely. For this,
an atomic this_cpu_cmpxchg is necessary.

Following the kernel convention for cmpxchg/cmpxchg_local,
add S390's this_cpu_cmpxchg_local.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

---

Index: linux-vmstat-remote/arch/s390/include/asm/percpu.h
===================================================================
--- linux-vmstat-remote.orig/arch/s390/include/asm/percpu.h
+++ linux-vmstat-remote/arch/s390/include/asm/percpu.h
@@ -148,6 +148,11 @@
#define this_cpu_cmpxchg_4(pcp, oval, nval) arch_this_cpu_cmpxchg(pcp, oval, nval)
#define this_cpu_cmpxchg_8(pcp, oval, nval) arch_this_cpu_cmpxchg(pcp, oval, nval)

+#define this_cpu_cmpxchg_local_1(pcp, oval, nval) arch_this_cpu_cmpxchg(pcp, oval, nval)
+#define this_cpu_cmpxchg_local_2(pcp, oval, nval) arch_this_cpu_cmpxchg(pcp, oval, nval)
+#define this_cpu_cmpxchg_local_4(pcp, oval, nval) arch_this_cpu_cmpxchg(pcp, oval, nval)
+#define this_cpu_cmpxchg_local_8(pcp, oval, nval) arch_this_cpu_cmpxchg(pcp, oval, nval)
+
#define arch_this_cpu_xchg(pcp, nval) \
({ \
typeof(pcp) *ptr__; \