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[Qemu-devel] [PULL v2 04/37] atomics: Add __nocheck atomic operations
From: |
Richard Henderson |
Subject: |
[Qemu-devel] [PULL v2 04/37] atomics: Add __nocheck atomic operations |
Date: |
Wed, 26 Oct 2016 09:15:30 -0700 |
While the check against sizeof(void *) is appropriate for
normal usage within qemu, there are places in which we want
wider operaions and have checked for their existance.
Reviewed-by: Emilio G. Cota <address@hidden>
Signed-off-by: Richard Henderson <address@hidden>
---
include/qemu/atomic.h | 36 +++++++++++++++++++++++++++---------
1 file changed, 27 insertions(+), 9 deletions(-)
diff --git a/include/qemu/atomic.h b/include/qemu/atomic.h
index a26a36b..878fa07 100644
--- a/include/qemu/atomic.h
+++ b/include/qemu/atomic.h
@@ -99,15 +99,21 @@
* no effect on the generated code but not using the atomic primitives
* will get flagged by sanitizers as a violation.
*/
+#define atomic_read__nocheck(ptr) \
+ __atomic_load_n(ptr, __ATOMIC_RELAXED)
+
#define atomic_read(ptr) \
({ \
QEMU_BUILD_BUG_ON(sizeof(*ptr) > sizeof(void *)); \
- __atomic_load_n(ptr, __ATOMIC_RELAXED); \
+ atomic_read__nocheck(ptr); \
})
+#define atomic_set__nocheck(ptr, i) \
+ __atomic_store_n(ptr, i, __ATOMIC_RELAXED)
+
#define atomic_set(ptr, i) do { \
QEMU_BUILD_BUG_ON(sizeof(*ptr) > sizeof(void *)); \
- __atomic_store_n(ptr, i, __ATOMIC_RELAXED); \
+ atomic_set__nocheck(ptr, i); \
} while(0)
/* See above: most compilers currently treat consume and acquire the
@@ -151,20 +157,27 @@
/* All the remaining operations are fully sequentially consistent */
+#define atomic_xchg__nocheck(ptr, i) ({ \
+ __atomic_exchange_n(ptr, (i), __ATOMIC_SEQ_CST); \
+})
+
#define atomic_xchg(ptr, i) ({ \
QEMU_BUILD_BUG_ON(sizeof(*ptr) > sizeof(void *)); \
- __atomic_exchange_n(ptr, i, __ATOMIC_SEQ_CST); \
+ atomic_xchg__nocheck(ptr, i); \
})
/* Returns the eventual value, failed or not */
-#define atomic_cmpxchg(ptr, old, new) \
- ({ \
- QEMU_BUILD_BUG_ON(sizeof(*ptr) > sizeof(void *)); \
+#define atomic_cmpxchg__nocheck(ptr, old, new) ({ \
typeof_strip_qual(*ptr) _old = (old); \
__atomic_compare_exchange_n(ptr, &_old, new, false, \
__ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST); \
_old; \
- })
+})
+
+#define atomic_cmpxchg(ptr, old, new) ({ \
+ QEMU_BUILD_BUG_ON(sizeof(*ptr) > sizeof(void *)); \
+ atomic_cmpxchg__nocheck(ptr, old, new); \
+})
/* Provide shorter names for GCC atomic builtins, return old value */
#define atomic_fetch_inc(ptr) __atomic_fetch_add(ptr, 1, __ATOMIC_SEQ_CST)
@@ -279,8 +292,11 @@
/* These will only be atomic if the processor does the fetch or store
* in a single issue memory operation
*/
-#define atomic_read(ptr) (*(__typeof__(*ptr) volatile*) (ptr))
-#define atomic_set(ptr, i) ((*(__typeof__(*ptr) volatile*) (ptr)) = (i))
+#define atomic_read__nocheck(p) (*(__typeof__(*(p)) volatile*) (p))
+#define atomic_set__nocheck(p, i) ((*(__typeof__(*(p)) volatile*) (p)) = (i))
+
+#define atomic_read(ptr) atomic_read__nocheck(ptr)
+#define atomic_set(ptr, i) atomic_set__nocheck(ptr,i)
/**
* atomic_rcu_read - reads a RCU-protected pointer to a local variable
@@ -341,6 +357,7 @@
#define atomic_xchg(ptr, i) (smp_mb(), __sync_lock_test_and_set(ptr, i))
#endif
#endif
+#define atomic_xchg__nocheck atomic_xchg
/* Provide shorter names for GCC atomic builtins. */
#define atomic_fetch_inc(ptr) __sync_fetch_and_add(ptr, 1)
@@ -360,6 +377,7 @@
#define atomic_xor_fetch(ptr, n) __sync_xor_and_fetch(ptr, n)
#define atomic_cmpxchg(ptr, old, new) __sync_val_compare_and_swap(ptr, old,
new)
+#define atomic_cmpxchg__nocheck(ptr, old, new) atomic_cmpxchg(ptr, old, new)
/* And even shorter names that return void. */
#define atomic_inc(ptr) ((void) __sync_fetch_and_add(ptr, 1))
--
2.7.4
- [Qemu-devel] [PULL v2 00/37] cmpxchg atomic operations, Richard Henderson, 2016/10/26
- [Qemu-devel] [PULL v2 03/37] atomics: add atomic_op_fetch variants, Richard Henderson, 2016/10/26
- [Qemu-devel] [PULL v2 02/37] atomics: add atomic_xor, Richard Henderson, 2016/10/26
- [Qemu-devel] [PULL v2 01/37] atomics: Add parameters to macros, Richard Henderson, 2016/10/26
- [Qemu-devel] [PULL v2 04/37] atomics: Add __nocheck atomic operations,
Richard Henderson <=
- [Qemu-devel] [PULL v2 09/37] linux-user: enable parallel code generation on clone, Richard Henderson, 2016/10/26
- [Qemu-devel] [PULL v2 07/37] int128: Add int128_make128, Richard Henderson, 2016/10/26
- [Qemu-devel] [PULL v2 05/37] exec: Avoid direct references to Int128 parts, Richard Henderson, 2016/10/26
- [Qemu-devel] [PULL v2 06/37] int128: Use __int128 if available, Richard Henderson, 2016/10/26
- [Qemu-devel] [PULL v2 10/37] cputlb: Replace SHIFT with DATA_SIZE, Richard Henderson, 2016/10/26
- [Qemu-devel] [PULL v2 14/37] cputlb: Tidy some macros, Richard Henderson, 2016/10/26
- [Qemu-devel] [PULL v2 12/37] cputlb: Remove includes from softmmu_template.h, Richard Henderson, 2016/10/26
- [Qemu-devel] [PULL v2 13/37] cputlb: Move most of iotlb code out of line, Richard Henderson, 2016/10/26
- [Qemu-devel] [PULL v2 11/37] cputlb: Move probe_write out of softmmu_template.h, Richard Henderson, 2016/10/26
- [Qemu-devel] [PULL v2 18/37] tcg: Emit barriers with parallel_cpus, Richard Henderson, 2016/10/26