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Diffstat (limited to 'arch/arm64/include/asm/atomic_ll_sc.h')
-rw-r--r--arch/arm64/include/asm/atomic_ll_sc.h217
1 files changed, 121 insertions, 96 deletions
diff --git a/arch/arm64/include/asm/atomic_ll_sc.h b/arch/arm64/include/asm/atomic_ll_sc.h
index c8c850bc3dfb..7b012148bfd6 100644
--- a/arch/arm64/include/asm/atomic_ll_sc.h
+++ b/arch/arm64/include/asm/atomic_ll_sc.h
@@ -10,83 +10,92 @@
#ifndef __ASM_ATOMIC_LL_SC_H
#define __ASM_ATOMIC_LL_SC_H
-#ifndef __ARM64_IN_ATOMIC_IMPL
-#error "please don't include this file directly"
+#include <linux/stringify.h>
+
+#if IS_ENABLED(CONFIG_ARM64_LSE_ATOMICS) && IS_ENABLED(CONFIG_AS_LSE)
+#define __LL_SC_FALLBACK(asm_ops) \
+" b 3f\n" \
+" .subsection 1\n" \
+"3:\n" \
+asm_ops "\n" \
+" b 4f\n" \
+" .previous\n" \
+"4:\n"
+#else
+#define __LL_SC_FALLBACK(asm_ops) asm_ops
+#endif
+
+#ifndef CONFIG_CC_HAS_K_CONSTRAINT
+#define K
#endif
/*
* AArch64 UP and SMP safe atomic ops. We use load exclusive and
* store exclusive to ensure that these are atomic. We may loop
* to ensure that the update happens.
- *
- * NOTE: these functions do *not* follow the PCS and must explicitly
- * save any clobbered registers other than x0 (regardless of return
- * value). This is achieved through -fcall-saved-* compiler flags for
- * this file, which unfortunately don't work on a per-function basis
- * (the optimize attribute silently ignores these options).
*/
-#define ATOMIC_OP(op, asm_op) \
-__LL_SC_INLINE void \
-__LL_SC_PREFIX(arch_atomic_##op(int i, atomic_t *v)) \
+#define ATOMIC_OP(op, asm_op, constraint) \
+static inline void \
+__ll_sc_atomic_##op(int i, atomic_t *v) \
{ \
unsigned long tmp; \
int result; \
\
asm volatile("// atomic_" #op "\n" \
+ __LL_SC_FALLBACK( \
" prfm pstl1strm, %2\n" \
"1: ldxr %w0, %2\n" \
" " #asm_op " %w0, %w0, %w3\n" \
" stxr %w1, %w0, %2\n" \
-" cbnz %w1, 1b" \
+" cbnz %w1, 1b\n") \
: "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \
- : "Ir" (i)); \
-} \
-__LL_SC_EXPORT(arch_atomic_##op);
+ : __stringify(constraint) "r" (i)); \
+}
-#define ATOMIC_OP_RETURN(name, mb, acq, rel, cl, op, asm_op) \
-__LL_SC_INLINE int \
-__LL_SC_PREFIX(arch_atomic_##op##_return##name(int i, atomic_t *v)) \
+#define ATOMIC_OP_RETURN(name, mb, acq, rel, cl, op, asm_op, constraint)\
+static inline int \
+__ll_sc_atomic_##op##_return##name(int i, atomic_t *v) \
{ \
unsigned long tmp; \
int result; \
\
asm volatile("// atomic_" #op "_return" #name "\n" \
+ __LL_SC_FALLBACK( \
" prfm pstl1strm, %2\n" \
"1: ld" #acq "xr %w0, %2\n" \
" " #asm_op " %w0, %w0, %w3\n" \
" st" #rel "xr %w1, %w0, %2\n" \
" cbnz %w1, 1b\n" \
-" " #mb \
+" " #mb ) \
: "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \
- : "Ir" (i) \
+ : __stringify(constraint) "r" (i) \
: cl); \
\
return result; \
-} \
-__LL_SC_EXPORT(arch_atomic_##op##_return##name);
+}
-#define ATOMIC_FETCH_OP(name, mb, acq, rel, cl, op, asm_op) \
-__LL_SC_INLINE int \
-__LL_SC_PREFIX(arch_atomic_fetch_##op##name(int i, atomic_t *v)) \
+#define ATOMIC_FETCH_OP(name, mb, acq, rel, cl, op, asm_op, constraint) \
+static inline int \
+__ll_sc_atomic_fetch_##op##name(int i, atomic_t *v) \
{ \
unsigned long tmp; \
int val, result; \
\
asm volatile("// atomic_fetch_" #op #name "\n" \
+ __LL_SC_FALLBACK( \
" prfm pstl1strm, %3\n" \
"1: ld" #acq "xr %w0, %3\n" \
" " #asm_op " %w1, %w0, %w4\n" \
" st" #rel "xr %w2, %w1, %3\n" \
" cbnz %w2, 1b\n" \
-" " #mb \
+" " #mb ) \
: "=&r" (result), "=&r" (val), "=&r" (tmp), "+Q" (v->counter) \
- : "Ir" (i) \
+ : __stringify(constraint) "r" (i) \
: cl); \
\
return result; \
-} \
-__LL_SC_EXPORT(arch_atomic_fetch_##op##name);
+}
#define ATOMIC_OPS(...) \
ATOMIC_OP(__VA_ARGS__) \
@@ -99,8 +108,8 @@ __LL_SC_EXPORT(arch_atomic_fetch_##op##name);
ATOMIC_FETCH_OP (_acquire, , a, , "memory", __VA_ARGS__)\
ATOMIC_FETCH_OP (_release, , , l, "memory", __VA_ARGS__)
-ATOMIC_OPS(add, add)
-ATOMIC_OPS(sub, sub)
+ATOMIC_OPS(add, add, I)
+ATOMIC_OPS(sub, sub, J)
#undef ATOMIC_OPS
#define ATOMIC_OPS(...) \
@@ -110,77 +119,82 @@ ATOMIC_OPS(sub, sub)
ATOMIC_FETCH_OP (_acquire, , a, , "memory", __VA_ARGS__)\
ATOMIC_FETCH_OP (_release, , , l, "memory", __VA_ARGS__)
-ATOMIC_OPS(and, and)
-ATOMIC_OPS(andnot, bic)
-ATOMIC_OPS(or, orr)
-ATOMIC_OPS(xor, eor)
+ATOMIC_OPS(and, and, K)
+ATOMIC_OPS(or, orr, K)
+ATOMIC_OPS(xor, eor, K)
+/*
+ * GAS converts the mysterious and undocumented BIC (immediate) alias to
+ * an AND (immediate) instruction with the immediate inverted. We don't
+ * have a constraint for this, so fall back to register.
+ */
+ATOMIC_OPS(andnot, bic, )
#undef ATOMIC_OPS
#undef ATOMIC_FETCH_OP
#undef ATOMIC_OP_RETURN
#undef ATOMIC_OP
-#define ATOMIC64_OP(op, asm_op) \
-__LL_SC_INLINE void \
-__LL_SC_PREFIX(arch_atomic64_##op(s64 i, atomic64_t *v)) \
+#define ATOMIC64_OP(op, asm_op, constraint) \
+static inline void \
+__ll_sc_atomic64_##op(s64 i, atomic64_t *v) \
{ \
s64 result; \
unsigned long tmp; \
\
asm volatile("// atomic64_" #op "\n" \
+ __LL_SC_FALLBACK( \
" prfm pstl1strm, %2\n" \
"1: ldxr %0, %2\n" \
" " #asm_op " %0, %0, %3\n" \
" stxr %w1, %0, %2\n" \
-" cbnz %w1, 1b" \
+" cbnz %w1, 1b") \
: "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \
- : "Ir" (i)); \
-} \
-__LL_SC_EXPORT(arch_atomic64_##op);
+ : __stringify(constraint) "r" (i)); \
+}
-#define ATOMIC64_OP_RETURN(name, mb, acq, rel, cl, op, asm_op) \
-__LL_SC_INLINE s64 \
-__LL_SC_PREFIX(arch_atomic64_##op##_return##name(s64 i, atomic64_t *v))\
+#define ATOMIC64_OP_RETURN(name, mb, acq, rel, cl, op, asm_op, constraint)\
+static inline long \
+__ll_sc_atomic64_##op##_return##name(s64 i, atomic64_t *v) \
{ \
s64 result; \
unsigned long tmp; \
\
asm volatile("// atomic64_" #op "_return" #name "\n" \
+ __LL_SC_FALLBACK( \
" prfm pstl1strm, %2\n" \
"1: ld" #acq "xr %0, %2\n" \
" " #asm_op " %0, %0, %3\n" \
" st" #rel "xr %w1, %0, %2\n" \
" cbnz %w1, 1b\n" \
-" " #mb \
+" " #mb ) \
: "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \
- : "Ir" (i) \
+ : __stringify(constraint) "r" (i) \
: cl); \
\
return result; \
-} \
-__LL_SC_EXPORT(arch_atomic64_##op##_return##name);
+}
-#define ATOMIC64_FETCH_OP(name, mb, acq, rel, cl, op, asm_op) \
-__LL_SC_INLINE s64 \
-__LL_SC_PREFIX(arch_atomic64_fetch_##op##name(s64 i, atomic64_t *v)) \
+#define ATOMIC64_FETCH_OP(name, mb, acq, rel, cl, op, asm_op, constraint)\
+static inline long \
+__ll_sc_atomic64_fetch_##op##name(s64 i, atomic64_t *v) \
{ \
s64 result, val; \
unsigned long tmp; \
\
asm volatile("// atomic64_fetch_" #op #name "\n" \
+ __LL_SC_FALLBACK( \
" prfm pstl1strm, %3\n" \
"1: ld" #acq "xr %0, %3\n" \
" " #asm_op " %1, %0, %4\n" \
" st" #rel "xr %w2, %1, %3\n" \
" cbnz %w2, 1b\n" \
-" " #mb \
+" " #mb ) \
: "=&r" (result), "=&r" (val), "=&r" (tmp), "+Q" (v->counter) \
- : "Ir" (i) \
+ : __stringify(constraint) "r" (i) \
: cl); \
\
return result; \
-} \
-__LL_SC_EXPORT(arch_atomic64_fetch_##op##name);
+}
#define ATOMIC64_OPS(...) \
ATOMIC64_OP(__VA_ARGS__) \
@@ -193,8 +207,8 @@ __LL_SC_EXPORT(arch_atomic64_fetch_##op##name);
ATOMIC64_FETCH_OP (_acquire,, a, , "memory", __VA_ARGS__) \
ATOMIC64_FETCH_OP (_release,, , l, "memory", __VA_ARGS__)
-ATOMIC64_OPS(add, add)
-ATOMIC64_OPS(sub, sub)
+ATOMIC64_OPS(add, add, I)
+ATOMIC64_OPS(sub, sub, J)
#undef ATOMIC64_OPS
#define ATOMIC64_OPS(...) \
@@ -204,23 +218,29 @@ ATOMIC64_OPS(sub, sub)
ATOMIC64_FETCH_OP (_acquire,, a, , "memory", __VA_ARGS__) \
ATOMIC64_FETCH_OP (_release,, , l, "memory", __VA_ARGS__)
-ATOMIC64_OPS(and, and)
-ATOMIC64_OPS(andnot, bic)
-ATOMIC64_OPS(or, orr)
-ATOMIC64_OPS(xor, eor)
+ATOMIC64_OPS(and, and, L)
+ATOMIC64_OPS(or, orr, L)
+ATOMIC64_OPS(xor, eor, L)
+/*
+ * GAS converts the mysterious and undocumented BIC (immediate) alias to
+ * an AND (immediate) instruction with the immediate inverted. We don't
+ * have a constraint for this, so fall back to register.
+ */
+ATOMIC64_OPS(andnot, bic, )
#undef ATOMIC64_OPS
#undef ATOMIC64_FETCH_OP
#undef ATOMIC64_OP_RETURN
#undef ATOMIC64_OP
-__LL_SC_INLINE s64
-__LL_SC_PREFIX(arch_atomic64_dec_if_positive(atomic64_t *v))
+static inline s64
+__ll_sc_atomic64_dec_if_positive(atomic64_t *v)
{
s64 result;
unsigned long tmp;
asm volatile("// atomic64_dec_if_positive\n"
+ __LL_SC_FALLBACK(
" prfm pstl1strm, %2\n"
"1: ldxr %0, %2\n"
" subs %0, %0, #1\n"
@@ -228,20 +248,19 @@ __LL_SC_PREFIX(arch_atomic64_dec_if_positive(atomic64_t *v))
" stlxr %w1, %0, %2\n"
" cbnz %w1, 1b\n"
" dmb ish\n"
-"2:"
+"2:")
: "=&r" (result), "=&r" (tmp), "+Q" (v->counter)
:
: "cc", "memory");
return result;
}
-__LL_SC_EXPORT(arch_atomic64_dec_if_positive);
-#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, \
+#define __CMPXCHG_CASE(w, sfx, name, sz, mb, acq, rel, cl, constraint) \
+static inline u##sz \
+__ll_sc__cmpxchg_case_##name##sz(volatile void *ptr, \
unsigned long old, \
- u##sz new)) \
+ u##sz new) \
{ \
unsigned long tmp; \
u##sz oldval; \
@@ -255,6 +274,7 @@ __LL_SC_PREFIX(__cmpxchg_case_##name##sz(volatile void *ptr, \
old = (u##sz)old; \
\
asm volatile( \
+ __LL_SC_FALLBACK( \
" prfm pstl1strm, %[v]\n" \
"1: ld" #acq "xr" #sfx "\t%" #w "[oldval], %[v]\n" \
" eor %" #w "[tmp], %" #w "[oldval], %" #w "[old]\n" \
@@ -262,46 +282,51 @@ __LL_SC_PREFIX(__cmpxchg_case_##name##sz(volatile void *ptr, \
" st" #rel "xr" #sfx "\t%w[tmp], %" #w "[new], %[v]\n" \
" cbnz %w[tmp], 1b\n" \
" " #mb "\n" \
- "2:" \
+ "2:") \
: [tmp] "=&r" (tmp), [oldval] "=&r" (oldval), \
[v] "+Q" (*(u##sz *)ptr) \
- : [old] "Kr" (old), [new] "r" (new) \
+ : [old] __stringify(constraint) "r" (old), [new] "r" (new) \
: cl); \
\
return oldval; \
-} \
-__LL_SC_EXPORT(__cmpxchg_case_##name##sz);
+}
-__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")
+/*
+ * Earlier versions of GCC (no later than 8.1.0) appear to incorrectly
+ * handle the 'K' constraint for the value 4294967295 - thus we use no
+ * constraint for 32 bit operations.
+ */
+__CMPXCHG_CASE(w, b, , 8, , , , , K)
+__CMPXCHG_CASE(w, h, , 16, , , , , K)
+__CMPXCHG_CASE(w, , , 32, , , , , K)
+__CMPXCHG_CASE( , , , 64, , , , , L)
+__CMPXCHG_CASE(w, b, acq_, 8, , a, , "memory", K)
+__CMPXCHG_CASE(w, h, acq_, 16, , a, , "memory", K)
+__CMPXCHG_CASE(w, , acq_, 32, , a, , "memory", K)
+__CMPXCHG_CASE( , , acq_, 64, , a, , "memory", L)
+__CMPXCHG_CASE(w, b, rel_, 8, , , l, "memory", K)
+__CMPXCHG_CASE(w, h, rel_, 16, , , l, "memory", K)
+__CMPXCHG_CASE(w, , rel_, 32, , , l, "memory", K)
+__CMPXCHG_CASE( , , rel_, 64, , , l, "memory", L)
+__CMPXCHG_CASE(w, b, mb_, 8, dmb ish, , l, "memory", K)
+__CMPXCHG_CASE(w, h, mb_, 16, dmb ish, , l, "memory", K)
+__CMPXCHG_CASE(w, , mb_, 32, dmb ish, , l, "memory", K)
+__CMPXCHG_CASE( , , mb_, 64, dmb ish, , l, "memory", L)
#undef __CMPXCHG_CASE
#define __CMPXCHG_DBL(name, mb, rel, cl) \
-__LL_SC_INLINE long \
-__LL_SC_PREFIX(__cmpxchg_double##name(unsigned long old1, \
+static inline long \
+__ll_sc__cmpxchg_double##name(unsigned long old1, \
unsigned long old2, \
unsigned long new1, \
unsigned long new2, \
- volatile void *ptr)) \
+ volatile void *ptr) \
{ \
unsigned long tmp, ret; \
\
asm volatile("// __cmpxchg_double" #name "\n" \
+ __LL_SC_FALLBACK( \
" prfm pstl1strm, %2\n" \
"1: ldxp %0, %1, %2\n" \
" eor %0, %0, %3\n" \
@@ -311,18 +336,18 @@ __LL_SC_PREFIX(__cmpxchg_double##name(unsigned long old1, \
" st" #rel "xp %w0, %5, %6, %2\n" \
" cbnz %w0, 1b\n" \
" " #mb "\n" \
- "2:" \
+ "2:") \
: "=&r" (tmp), "=&r" (ret), "+Q" (*(unsigned long *)ptr) \
: "r" (old1), "r" (old2), "r" (new1), "r" (new2) \
: cl); \
\
return ret; \
-} \
-__LL_SC_EXPORT(__cmpxchg_double##name);
+}
__CMPXCHG_DBL( , , , )
__CMPXCHG_DBL(_mb, dmb ish, l, "memory")
#undef __CMPXCHG_DBL
+#undef K
#endif /* __ASM_ATOMIC_LL_SC_H */