From: Will Deacon <will.dea...@arm.com>

commit 5ef3fe4cecdf82fdd71ce78988403963d01444d4 upstream.

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.dea...@arm.com>
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 arch/arm64/include/asm/atomic_ll_sc.h |   53 +++++++--------
 arch/arm64/include/asm/atomic_lse.h   |   46 ++++++-------
 arch/arm64/include/asm/cmpxchg.h      |  116 +++++++++++++++++-----------------
 3 files changed, 108 insertions(+), 107 deletions(-)

--- 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(
 }
 __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
 
--- a/arch/arm64/include/asm/atomic_lse.h
+++ b/arch/arm64/include/asm/atomic_lse.h
@@ -446,22 +446,22 @@ static inline long atomic64_dec_if_posit
 
 #define __LL_SC_CMPXCHG(op)    __LL_SC_CALL(__cmpxchg_case_##op)
 
-#define __CMPXCHG_CASE(w, sz, name, mb, cl...)                         \
-static inline unsigned long __cmpxchg_case_##name(volatile void *ptr,  \
-                                                 unsigned long old,    \
-                                                 unsigned long new)    \
+#define __CMPXCHG_CASE(w, sfx, name, sz, mb, cl...)                    \
+static inline u##sz __cmpxchg_case_##name##sz(volatile void *ptr,      \
+                                             unsigned long old,        \
+                                             u##sz new)                \
 {                                                                      \
        register unsigned long x0 asm ("x0") = (unsigned long)ptr;      \
        register unsigned long x1 asm ("x1") = old;                     \
-       register unsigned long x2 asm ("x2") = new;                     \
+       register u##sz x2 asm ("x2") = new;                             \
                                                                        \
        asm volatile(ARM64_LSE_ATOMIC_INSN(                             \
        /* LL/SC */                                                     \
-       __LL_SC_CMPXCHG(name)                                           \
+       __LL_SC_CMPXCHG(name##sz)                                       \
        __nops(2),                                                      \
        /* LSE atomics */                                               \
        "       mov     " #w "30, %" #w "[old]\n"                       \
-       "       cas" #mb #sz "\t" #w "30, %" #w "[new], %[v]\n"         \
+       "       cas" #mb #sfx "\t" #w "30, %" #w "[new], %[v]\n"        \
        "       mov     %" #w "[ret], " #w "30")                        \
        : [ret] "+r" (x0), [v] "+Q" (*(unsigned long *)ptr)             \
        : [old] "r" (x1), [new] "r" (x2)                                \
@@ -470,22 +470,22 @@ static inline unsigned long __cmpxchg_ca
        return x0;                                                      \
 }
 
-__CMPXCHG_CASE(w, b,     1,   )
-__CMPXCHG_CASE(w, h,     2,   )
-__CMPXCHG_CASE(w,  ,     4,   )
-__CMPXCHG_CASE(x,  ,     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(x,  , 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(x,  , rel_8,  l, "memory")
-__CMPXCHG_CASE(w, b,  mb_1, al, "memory")
-__CMPXCHG_CASE(w, h,  mb_2, al, "memory")
-__CMPXCHG_CASE(w,  ,  mb_4, al, "memory")
-__CMPXCHG_CASE(x,  ,  mb_8, al, "memory")
+__CMPXCHG_CASE(w, b,     ,  8,   )
+__CMPXCHG_CASE(w, h,     , 16,   )
+__CMPXCHG_CASE(w,  ,     , 32,   )
+__CMPXCHG_CASE(x,  ,     , 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(x,  , 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(x,  , rel_, 64,  l, "memory")
+__CMPXCHG_CASE(w, b,  mb_,  8, al, "memory")
+__CMPXCHG_CASE(w, h,  mb_, 16, al, "memory")
+__CMPXCHG_CASE(w,  ,  mb_, 32, al, "memory")
+__CMPXCHG_CASE(x,  ,  mb_, 64, al, "memory")
 
 #undef __LL_SC_CMPXCHG
 #undef __CMPXCHG_CASE
--- a/arch/arm64/include/asm/cmpxchg.h
+++ b/arch/arm64/include/asm/cmpxchg.h
@@ -29,46 +29,46 @@
  * barrier case is generated as release+dmb for the former and
  * acquire+release for the latter.
  */
-#define __XCHG_CASE(w, sz, name, mb, nop_lse, acq, acq_lse, rel, cl)   \
-static inline unsigned long __xchg_case_##name(unsigned long x,                
\
-                                              volatile void *ptr)      \
-{                                                                      \
-       unsigned long ret, tmp;                                         \
-                                                                       \
-       asm volatile(ARM64_LSE_ATOMIC_INSN(                             \
-       /* LL/SC */                                                     \
-       "       prfm    pstl1strm, %2\n"                                \
-       "1:     ld" #acq "xr" #sz "\t%" #w "0, %2\n"                    \
-       "       st" #rel "xr" #sz "\t%w1, %" #w "3, %2\n"               \
-       "       cbnz    %w1, 1b\n"                                      \
-       "       " #mb,                                                  \
-       /* LSE atomics */                                               \
-       "       swp" #acq_lse #rel #sz "\t%" #w "3, %" #w "0, %2\n"     \
-               __nops(3)                                               \
-       "       " #nop_lse)                                             \
-       : "=&r" (ret), "=&r" (tmp), "+Q" (*(unsigned long *)ptr)        \
-       : "r" (x)                                                       \
-       : cl);                                                          \
-                                                                       \
-       return ret;                                                     \
+#define __XCHG_CASE(w, sfx, name, sz, mb, nop_lse, acq, acq_lse, rel, cl)      
\
+static inline u##sz __xchg_case_##name##sz(u##sz x, volatile void *ptr)        
        \
+{                                                                              
\
+       u##sz ret;                                                              
\
+       unsigned long tmp;                                                      
\
+                                                                               
\
+       asm volatile(ARM64_LSE_ATOMIC_INSN(                                     
\
+       /* LL/SC */                                                             
\
+       "       prfm    pstl1strm, %2\n"                                        
\
+       "1:     ld" #acq "xr" #sfx "\t%" #w "0, %2\n"                           
\
+       "       st" #rel "xr" #sfx "\t%w1, %" #w "3, %2\n"                      
\
+       "       cbnz    %w1, 1b\n"                                              
\
+       "       " #mb,                                                          
\
+       /* LSE atomics */                                                       
\
+       "       swp" #acq_lse #rel #sfx "\t%" #w "3, %" #w "0, %2\n"            
\
+               __nops(3)                                                       
\
+       "       " #nop_lse)                                                     
\
+       : "=&r" (ret), "=&r" (tmp), "+Q" (*(u##sz *)ptr)                        
\
+       : "r" (x)                                                               
\
+       : cl);                                                                  
\
+                                                                               
\
+       return ret;                                                             
\
 }
 
-__XCHG_CASE(w, b,     1,        ,    ,  ,  ,  ,         )
-__XCHG_CASE(w, h,     2,        ,    ,  ,  ,  ,         )
-__XCHG_CASE(w,  ,     4,        ,    ,  ,  ,  ,         )
-__XCHG_CASE( ,  ,     8,        ,    ,  ,  ,  ,         )
-__XCHG_CASE(w, b, acq_1,        ,    , a, a,  , "memory")
-__XCHG_CASE(w, h, acq_2,        ,    , a, a,  , "memory")
-__XCHG_CASE(w,  , acq_4,        ,    , a, a,  , "memory")
-__XCHG_CASE( ,  , acq_8,        ,    , a, a,  , "memory")
-__XCHG_CASE(w, b, rel_1,        ,    ,  ,  , l, "memory")
-__XCHG_CASE(w, h, rel_2,        ,    ,  ,  , l, "memory")
-__XCHG_CASE(w,  , rel_4,        ,    ,  ,  , l, "memory")
-__XCHG_CASE( ,  , rel_8,        ,    ,  ,  , l, "memory")
-__XCHG_CASE(w, b,  mb_1, dmb ish, nop,  , a, l, "memory")
-__XCHG_CASE(w, h,  mb_2, dmb ish, nop,  , a, l, "memory")
-__XCHG_CASE(w,  ,  mb_4, dmb ish, nop,  , a, l, "memory")
-__XCHG_CASE( ,  ,  mb_8, dmb ish, nop,  , a, l, "memory")
+__XCHG_CASE(w, b,     ,  8,        ,    ,  ,  ,  ,         )
+__XCHG_CASE(w, h,     , 16,        ,    ,  ,  ,  ,         )
+__XCHG_CASE(w,  ,     , 32,        ,    ,  ,  ,  ,         )
+__XCHG_CASE( ,  ,     , 64,        ,    ,  ,  ,  ,         )
+__XCHG_CASE(w, b, acq_,  8,        ,    , a, a,  , "memory")
+__XCHG_CASE(w, h, acq_, 16,        ,    , a, a,  , "memory")
+__XCHG_CASE(w,  , acq_, 32,        ,    , a, a,  , "memory")
+__XCHG_CASE( ,  , acq_, 64,        ,    , a, a,  , "memory")
+__XCHG_CASE(w, b, rel_,  8,        ,    ,  ,  , l, "memory")
+__XCHG_CASE(w, h, rel_, 16,        ,    ,  ,  , l, "memory")
+__XCHG_CASE(w,  , rel_, 32,        ,    ,  ,  , l, "memory")
+__XCHG_CASE( ,  , rel_, 64,        ,    ,  ,  , l, "memory")
+__XCHG_CASE(w, b,  mb_,  8, dmb ish, nop,  , a, l, "memory")
+__XCHG_CASE(w, h,  mb_, 16, dmb ish, nop,  , a, l, "memory")
+__XCHG_CASE(w,  ,  mb_, 32, dmb ish, nop,  , a, l, "memory")
+__XCHG_CASE( ,  ,  mb_, 64, dmb ish, nop,  , a, l, "memory")
 
 #undef __XCHG_CASE
 
@@ -79,13 +79,13 @@ static __always_inline  unsigned long __
 {                                                                      \
        switch (size) {                                                 \
        case 1:                                                         \
-               return __xchg_case##sfx##_1(x, ptr);                    \
+               return __xchg_case##sfx##_8(x, ptr);                    \
        case 2:                                                         \
-               return __xchg_case##sfx##_2(x, ptr);                    \
+               return __xchg_case##sfx##_16(x, ptr);                   \
        case 4:                                                         \
-               return __xchg_case##sfx##_4(x, ptr);                    \
+               return __xchg_case##sfx##_32(x, ptr);                   \
        case 8:                                                         \
-               return __xchg_case##sfx##_8(x, ptr);                    \
+               return __xchg_case##sfx##_64(x, ptr);                   \
        default:                                                        \
                BUILD_BUG();                                            \
        }                                                               \
@@ -122,13 +122,13 @@ static __always_inline unsigned long __c
 {                                                                      \
        switch (size) {                                                 \
        case 1:                                                         \
-               return __cmpxchg_case##sfx##_1(ptr, (u8)old, new);      \
+               return __cmpxchg_case##sfx##_8(ptr, (u8)old, new);      \
        case 2:                                                         \
-               return __cmpxchg_case##sfx##_2(ptr, (u16)old, new);     \
+               return __cmpxchg_case##sfx##_16(ptr, (u16)old, new);    \
        case 4:                                                         \
-               return __cmpxchg_case##sfx##_4(ptr, old, new);          \
+               return __cmpxchg_case##sfx##_32(ptr, old, new);         \
        case 8:                                                         \
-               return __cmpxchg_case##sfx##_8(ptr, old, new);          \
+               return __cmpxchg_case##sfx##_64(ptr, old, new);         \
        default:                                                        \
                BUILD_BUG();                                            \
        }                                                               \
@@ -222,16 +222,16 @@ __CMPXCHG_GEN(_mb)
        __ret;                                                          \
 })
 
-#define __CMPWAIT_CASE(w, sz, name)                                    \
-static inline void __cmpwait_case_##name(volatile void *ptr,           \
-                                        unsigned long val)             \
+#define __CMPWAIT_CASE(w, sfx, sz)                                     \
+static inline void __cmpwait_case_##sz(volatile void *ptr,             \
+                                      unsigned long val)               \
 {                                                                      \
        unsigned long tmp;                                              \
                                                                        \
        asm volatile(                                                   \
        "       sevl\n"                                                 \
        "       wfe\n"                                                  \
-       "       ldxr" #sz "\t%" #w "[tmp], %[v]\n"                      \
+       "       ldxr" #sfx "\t%" #w "[tmp], %[v]\n"                     \
        "       eor     %" #w "[tmp], %" #w "[tmp], %" #w "[val]\n"     \
        "       cbnz    %" #w "[tmp], 1f\n"                             \
        "       wfe\n"                                                  \
@@ -240,10 +240,10 @@ static inline void __cmpwait_case_##name
        : [val] "r" (val));                                             \
 }
 
-__CMPWAIT_CASE(w, b, 1);
-__CMPWAIT_CASE(w, h, 2);
-__CMPWAIT_CASE(w,  , 4);
-__CMPWAIT_CASE( ,  , 8);
+__CMPWAIT_CASE(w, b, 8);
+__CMPWAIT_CASE(w, h, 16);
+__CMPWAIT_CASE(w,  , 32);
+__CMPWAIT_CASE( ,  , 64);
 
 #undef __CMPWAIT_CASE
 
@@ -254,13 +254,13 @@ static __always_inline void __cmpwait##s
 {                                                                      \
        switch (size) {                                                 \
        case 1:                                                         \
-               return __cmpwait_case##sfx##_1(ptr, (u8)val);           \
+               return __cmpwait_case##sfx##_8(ptr, (u8)val);           \
        case 2:                                                         \
-               return __cmpwait_case##sfx##_2(ptr, (u16)val);          \
+               return __cmpwait_case##sfx##_16(ptr, (u16)val);         \
        case 4:                                                         \
-               return __cmpwait_case##sfx##_4(ptr, val);               \
+               return __cmpwait_case##sfx##_32(ptr, val);              \
        case 8:                                                         \
-               return __cmpwait_case##sfx##_8(ptr, val);               \
+               return __cmpwait_case##sfx##_64(ptr, val);              \
        default:                                                        \
                BUILD_BUG();                                            \
        }                                                               \


Reply via email to