Author: hselasky
Date: Thu Jan 21 17:52:55 2016
New Revision: 294520
URL: https://svnweb.freebsd.org/changeset/base/294520
Log:
LinuxKPI atomic fixes:
- Fix implementation of atomic_add_unless(). The atomic_cmpset_int()
function returns a boolean and not the previous value of the atomic
variable.
- The atomic counters should be signed according to Linux.
- Some minor cosmetics and styling while at it.
Reviewed by: alfred @
MFC after: 1 week
Sponsored by: Mellanox Technologies
Modified:
head/sys/compat/linuxkpi/common/include/asm/atomic-long.h
head/sys/compat/linuxkpi/common/include/asm/atomic.h
Modified: head/sys/compat/linuxkpi/common/include/asm/atomic-long.h
==============================================================================
--- head/sys/compat/linuxkpi/common/include/asm/atomic-long.h Thu Jan 21
17:49:10 2016 (r294519)
+++ head/sys/compat/linuxkpi/common/include/asm/atomic-long.h Thu Jan 21
17:52:55 2016 (r294520)
@@ -36,7 +36,7 @@
#include <machine/atomic.h>
typedef struct {
- volatile u_long counter;
+ volatile long counter;
} atomic_long_t;
#define atomic_long_add(i, v) atomic_long_add_return((i), (v))
Modified: head/sys/compat/linuxkpi/common/include/asm/atomic.h
==============================================================================
--- head/sys/compat/linuxkpi/common/include/asm/atomic.h Thu Jan 21
17:49:10 2016 (r294519)
+++ head/sys/compat/linuxkpi/common/include/asm/atomic.h Thu Jan 21
17:52:55 2016 (r294520)
@@ -2,7 +2,7 @@
* Copyright (c) 2010 Isilon Systems, Inc.
* Copyright (c) 2010 iX Systems, Inc.
* Copyright (c) 2010 Panasas, Inc.
- * Copyright (c) 2013, 2014 Mellanox Technologies, Ltd.
+ * Copyright (c) 2013-2016 Mellanox Technologies, Ltd.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@@ -36,9 +36,13 @@
#include <machine/atomic.h>
typedef struct {
- volatile u_int counter;
+ volatile int counter;
} atomic_t;
+/*------------------------------------------------------------------------*
+ * 32-bit atomic operations
+ *------------------------------------------------------------------------*/
+
#define atomic_add(i, v) atomic_add_return((i), (v))
#define atomic_sub(i, v) atomic_sub_return((i), (v))
#define atomic_inc_return(v) atomic_add_return(1, (v))
@@ -46,7 +50,8 @@ typedef struct {
#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) ==
0)
#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
#define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0)
-#define atomic_dec_return(v) atomic_sub_return(1, (v))
+#define atomic_dec_return(v) atomic_sub_return(1, (v))
+#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
static inline int
atomic_add_return(int i, atomic_t *v)
@@ -84,24 +89,19 @@ atomic_dec(atomic_t *v)
return atomic_fetchadd_int(&v->counter, -1) - 1;
}
-static inline int atomic_add_unless(atomic_t *v, int a, int u)
+static inline int
+atomic_add_unless(atomic_t *v, int a, int u)
{
- int c, old;
- c = atomic_read(v);
- for (;;) {
- if (unlikely(c == (u)))
- break;
- old = atomic_cmpset_int(&v->counter, c, c + (a));
- if (likely(old == c))
- break;
- c = old;
- }
- return c != (u);
-}
-
-#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
-
-
+ int c;
+ for (;;) {
+ c = atomic_read(v);
+ if (unlikely(c == u))
+ break;
+ if (likely(atomic_cmpset_int(&v->counter, c, c + a)))
+ break;
+ }
+ return (c != u);
+}
-#endif /* _ASM_ATOMIC_H_ */
+#endif /* _ASM_ATOMIC_H_ */
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