[PATCH v3 11/11] s390/cpum_sf: Convert to cmpxchg128()

Peter Zijlstra
2023-05-15T08:07:40Z

Now that there is a cross arch u128 and cmpxchg128(), use those
instead of the custom CDSG helper.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
---
arch/s390/include/asm/cpu_mf.h | 2 +-
arch/s390/kernel/perf_cpum_sf.c | 16 +++-------------
2 files changed, 4 insertions(+), 14 deletions(-)

--- a/arch/s390/include/asm/cpu_mf.h
+++ b/arch/s390/include/asm/cpu_mf.h
@@ -140,7 +140,7 @@ union hws_trailer_header {
unsigned int dsdes:16; /* 48-63: size of diagnostic SDE */
unsigned long long overflow; /* 64 - Overflow Count */
};
- __uint128_t val;
+ u128 val;
};

struct hws_trailer_entry {
--- a/arch/s390/kernel/perf_cpum_sf.c
+++ b/arch/s390/kernel/perf_cpum_sf.c
@@ -1275,16 +1275,6 @@ static void hw_collect_samples(struct pe
}
}

-static inline __uint128_t __cdsg(__uint128_t *ptr, __uint128_t old, __uint128_t new)
-{
- asm volatile(
- " cdsg %[old],%[new],%[ptr]\n"
- : [old] "+d" (old), [ptr] "+QS" (*ptr)
- : [new] "d" (new)
- : "memory", "cc");
- return old;
-}
-
/* hw_perf_event_update() - Process sampling buffer
* @event: The perf event
* @flush_all: Flag to also flush partially filled sample-data-blocks
@@ -1362,7 +1352,7 @@ static void hw_perf_event_update(struct
new.f = 0;
new.a = 1;
new.overflow = 0;
- prev.val = __cdsg(&te->header.val, old.val, new.val);
+ prev.val = cmpxchg128(&te->header.val, old.val, new.val);
} while (prev.val != old.val);

/* Advance to next sample-data-block */
@@ -1572,7 +1562,7 @@ static bool aux_set_alert(struct aux_buf
}
new.a = 1;
new.overflow = 0;
- prev.val = __cdsg(&te->header.val, old.val, new.val);
+ prev.val = cmpxchg128(&te->header.val, old.val, new.val);
} while (prev.val != old.val);
return true;
}
@@ -1646,7 +1636,7 @@ static bool aux_reset_buffer(struct aux_
new.a = 1;
else
new.a = 0;
- prev.val = __cdsg(&te->header.val, old.val, new.val);
+ prev.val = cmpxchg128(&te->header.val, old.val, new.val);
} while (prev.val != old.val);
*overflow += orig_overflow;
}