b7882b7c65
Linus noted that the atomic64_t primitives are all inlines currently which is crazy because these functions have a large register footprint anyway. Move them to a separate file: arch/x86/lib/atomic64_32.c Also, while at it, rename all uses of 'unsigned long long' to the much shorter u64. This makes the appearance of the prototypes a lot nicer - and it also uncovered a few bugs where (yet unused) API variants had 'long' as their return type instead of u64. [ More intrusive changes are not yet done in this patch. ] Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> LKML-Reference: <alpine.LFD.2.01.0907021653030.3210@localhost.localdomain> Signed-off-by: Ingo Molnar <mingo@elte.hu>
217 lines
4.3 KiB
C
217 lines
4.3 KiB
C
#include <linux/compiler.h>
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#include <linux/types.h>
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#include <asm/processor.h>
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#include <asm/cmpxchg.h>
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#include <asm/atomic.h>
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static inline u64 cmpxchg8b(u64 *ptr, u64 old, u64 new)
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{
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asm volatile(
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LOCK_PREFIX "cmpxchg8b (%[ptr])\n"
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: "=A" (old)
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: [ptr] "D" (ptr),
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"A" (old),
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"b" (ll_low(new)),
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"c" (ll_high(new))
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: "memory");
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return old;
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}
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u64 atomic64_cmpxchg(atomic64_t *ptr, u64 old_val, u64 new_val)
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{
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return cmpxchg8b(&ptr->counter, old_val, new_val);
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}
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/**
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* atomic64_xchg - xchg atomic64 variable
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* @ptr: pointer to type atomic64_t
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* @new_val: value to assign
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*
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* Atomically xchgs the value of @ptr to @new_val and returns
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* the old value.
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*/
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u64 atomic64_xchg(atomic64_t *ptr, u64 new_val)
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{
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u64 old_val;
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do {
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old_val = atomic_read(ptr);
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} while (atomic64_cmpxchg(ptr, old_val, new_val) != old_val);
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return old_val;
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}
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/**
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* atomic64_set - set atomic64 variable
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* @ptr: pointer to type atomic64_t
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* @new_val: value to assign
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*
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* Atomically sets the value of @ptr to @new_val.
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*/
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void atomic64_set(atomic64_t *ptr, u64 new_val)
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{
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atomic64_xchg(ptr, new_val);
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}
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/**
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* atomic64_read - read atomic64 variable
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* @ptr: pointer to type atomic64_t
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*
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* Atomically reads the value of @ptr and returns it.
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*/
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u64 atomic64_read(atomic64_t *ptr)
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{
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u64 curr_val;
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do {
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curr_val = __atomic64_read(ptr);
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} while (atomic64_cmpxchg(ptr, curr_val, curr_val) != curr_val);
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return curr_val;
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}
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/**
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* atomic64_add_return - add and return
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* @delta: integer value to add
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* @ptr: pointer to type atomic64_t
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*
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* Atomically adds @delta to @ptr and returns @delta + *@ptr
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*/
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u64 atomic64_add_return(u64 delta, atomic64_t *ptr)
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{
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u64 old_val, new_val;
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do {
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old_val = atomic_read(ptr);
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new_val = old_val + delta;
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} while (atomic64_cmpxchg(ptr, old_val, new_val) != old_val);
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return new_val;
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}
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u64 atomic64_sub_return(u64 delta, atomic64_t *ptr)
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{
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return atomic64_add_return(-delta, ptr);
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}
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u64 atomic64_inc_return(atomic64_t *ptr)
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{
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return atomic64_add_return(1, ptr);
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}
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u64 atomic64_dec_return(atomic64_t *ptr)
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{
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return atomic64_sub_return(1, ptr);
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}
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/**
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* atomic64_add - add integer to atomic64 variable
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* @delta: integer value to add
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* @ptr: pointer to type atomic64_t
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*
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* Atomically adds @delta to @ptr.
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*/
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void atomic64_add(u64 delta, atomic64_t *ptr)
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{
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atomic64_add_return(delta, ptr);
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}
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/**
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* atomic64_sub - subtract the atomic64 variable
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* @delta: integer value to subtract
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* @ptr: pointer to type atomic64_t
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*
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* Atomically subtracts @delta from @ptr.
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*/
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void atomic64_sub(u64 delta, atomic64_t *ptr)
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{
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atomic64_add(-delta, ptr);
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}
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/**
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* atomic64_sub_and_test - subtract value from variable and test result
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* @delta: integer value to subtract
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* @ptr: pointer to type atomic64_t
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*
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* Atomically subtracts @delta from @ptr and returns
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* true if the result is zero, or false for all
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* other cases.
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*/
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int atomic64_sub_and_test(u64 delta, atomic64_t *ptr)
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{
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u64 old_val = atomic64_sub_return(delta, ptr);
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return old_val == 0;
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}
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/**
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* atomic64_inc - increment atomic64 variable
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* @ptr: pointer to type atomic64_t
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*
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* Atomically increments @ptr by 1.
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*/
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void atomic64_inc(atomic64_t *ptr)
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{
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atomic64_add(1, ptr);
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}
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/**
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* atomic64_dec - decrement atomic64 variable
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* @ptr: pointer to type atomic64_t
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*
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* Atomically decrements @ptr by 1.
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*/
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void atomic64_dec(atomic64_t *ptr)
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{
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atomic64_sub(1, ptr);
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}
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/**
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* atomic64_dec_and_test - decrement and test
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* @ptr: pointer to type atomic64_t
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*
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* Atomically decrements @ptr by 1 and
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* returns true if the result is 0, or false for all other
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* cases.
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*/
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int atomic64_dec_and_test(atomic64_t *ptr)
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{
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return atomic64_sub_and_test(1, ptr);
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}
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/**
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* atomic64_inc_and_test - increment and test
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* @ptr: pointer to type atomic64_t
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*
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* Atomically increments @ptr by 1
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* and returns true if the result is zero, or false for all
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* other cases.
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*/
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int atomic64_inc_and_test(atomic64_t *ptr)
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{
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return atomic64_sub_and_test(-1, ptr);
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}
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/**
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* atomic64_add_negative - add and test if negative
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* @delta: integer value to add
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* @ptr: pointer to type atomic64_t
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*
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* Atomically adds @delta to @ptr and returns true
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* if the result is negative, or false when
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* result is greater than or equal to zero.
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*/
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int atomic64_add_negative(u64 delta, atomic64_t *ptr)
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{
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long long old_val = atomic64_add_return(delta, ptr);
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return old_val < 0;
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}
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