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| author | Will Deacon <will.deacon@arm.com> | 2018-09-13 13:30:45 +0100 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2018-12-07 17:27:55 +0000 |
| commit | 5ef3fe4cecdf82fdd71ce78988403963d01444d4 (patch) | |
| tree | 937f28f9e3beea1a63e0d21c4c95bf604af3ade2 /arch/arm64/include/asm/atomic_ll_sc.h | |
| parent | 396244692232fcf0881cb6ba2404be2906f47681 (diff) | |
| download | linux-5ef3fe4cecdf82fdd71ce78988403963d01444d4.tar.gz linux-5ef3fe4cecdf82fdd71ce78988403963d01444d4.tar.bz2 linux-5ef3fe4cecdf82fdd71ce78988403963d01444d4.zip | |
arm64: Avoid redundant type conversions in xchg() and cmpxchg()
Our atomic instructions (either LSE atomics of LDXR/STXR sequences)
natively support byte, half-word, word and double-word memory accesses
so there is no need to mask the data register prior to being stored.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/include/asm/atomic_ll_sc.h')
| -rw-r--r-- | arch/arm64/include/asm/atomic_ll_sc.h | 53 |
1 files changed, 27 insertions, 26 deletions
diff --git a/arch/arm64/include/asm/atomic_ll_sc.h b/arch/arm64/include/asm/atomic_ll_sc.h index f5a2d09afb38..f02d3bf7b9e6 100644 --- a/arch/arm64/include/asm/atomic_ll_sc.h +++ b/arch/arm64/include/asm/atomic_ll_sc.h @@ -248,48 +248,49 @@ __LL_SC_PREFIX(atomic64_dec_if_positive(atomic64_t *v)) } __LL_SC_EXPORT(atomic64_dec_if_positive); -#define __CMPXCHG_CASE(w, sz, name, mb, acq, rel, cl) \ -__LL_SC_INLINE unsigned long \ -__LL_SC_PREFIX(__cmpxchg_case_##name(volatile void *ptr, \ - unsigned long old, \ - unsigned long new)) \ +#define __CMPXCHG_CASE(w, sfx, name, sz, mb, acq, rel, cl) \ +__LL_SC_INLINE u##sz \ +__LL_SC_PREFIX(__cmpxchg_case_##name##sz(volatile void *ptr, \ + unsigned long old, \ + u##sz new)) \ { \ - unsigned long tmp, oldval; \ + unsigned long tmp; \ + u##sz oldval; \ \ asm volatile( \ " prfm pstl1strm, %[v]\n" \ - "1: ld" #acq "xr" #sz "\t%" #w "[oldval], %[v]\n" \ + "1: ld" #acq "xr" #sfx "\t%" #w "[oldval], %[v]\n" \ " eor %" #w "[tmp], %" #w "[oldval], %" #w "[old]\n" \ " cbnz %" #w "[tmp], 2f\n" \ - " st" #rel "xr" #sz "\t%w[tmp], %" #w "[new], %[v]\n" \ + " st" #rel "xr" #sfx "\t%w[tmp], %" #w "[new], %[v]\n" \ " cbnz %w[tmp], 1b\n" \ " " #mb "\n" \ "2:" \ : [tmp] "=&r" (tmp), [oldval] "=&r" (oldval), \ - [v] "+Q" (*(unsigned long *)ptr) \ + [v] "+Q" (*(u##sz *)ptr) \ : [old] "Lr" (old), [new] "r" (new) \ : cl); \ \ return oldval; \ } \ -__LL_SC_EXPORT(__cmpxchg_case_##name); +__LL_SC_EXPORT(__cmpxchg_case_##name##sz); -__CMPXCHG_CASE(w, b, 1, , , , ) -__CMPXCHG_CASE(w, h, 2, , , , ) -__CMPXCHG_CASE(w, , 4, , , , ) -__CMPXCHG_CASE( , , 8, , , , ) -__CMPXCHG_CASE(w, b, acq_1, , a, , "memory") -__CMPXCHG_CASE(w, h, acq_2, , a, , "memory") -__CMPXCHG_CASE(w, , acq_4, , a, , "memory") -__CMPXCHG_CASE( , , acq_8, , a, , "memory") -__CMPXCHG_CASE(w, b, rel_1, , , l, "memory") -__CMPXCHG_CASE(w, h, rel_2, , , l, "memory") -__CMPXCHG_CASE(w, , rel_4, , , l, "memory") -__CMPXCHG_CASE( , , rel_8, , , l, "memory") -__CMPXCHG_CASE(w, b, mb_1, dmb ish, , l, "memory") -__CMPXCHG_CASE(w, h, mb_2, dmb ish, , l, "memory") -__CMPXCHG_CASE(w, , mb_4, dmb ish, , l, "memory") -__CMPXCHG_CASE( , , mb_8, dmb ish, , l, "memory") +__CMPXCHG_CASE(w, b, , 8, , , , ) +__CMPXCHG_CASE(w, h, , 16, , , , ) +__CMPXCHG_CASE(w, , , 32, , , , ) +__CMPXCHG_CASE( , , , 64, , , , ) +__CMPXCHG_CASE(w, b, acq_, 8, , a, , "memory") +__CMPXCHG_CASE(w, h, acq_, 16, , a, , "memory") +__CMPXCHG_CASE(w, , acq_, 32, , a, , "memory") +__CMPXCHG_CASE( , , acq_, 64, , a, , "memory") +__CMPXCHG_CASE(w, b, rel_, 8, , , l, "memory") +__CMPXCHG_CASE(w, h, rel_, 16, , , l, "memory") +__CMPXCHG_CASE(w, , rel_, 32, , , l, "memory") +__CMPXCHG_CASE( , , rel_, 64, , , l, "memory") +__CMPXCHG_CASE(w, b, mb_, 8, dmb ish, , l, "memory") +__CMPXCHG_CASE(w, h, mb_, 16, dmb ish, , l, "memory") +__CMPXCHG_CASE(w, , mb_, 32, dmb ish, , l, "memory") +__CMPXCHG_CASE( , , mb_, 64, dmb ish, , l, "memory") #undef __CMPXCHG_CASE |