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author | 2015-08-04 12:17:53 -0700 | |
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committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/xtensa/include/asm/atomic.h | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/xtensa/include/asm/atomic.h')
-rw-r--r-- | kernel/arch/xtensa/include/asm/atomic.h | 324 |
1 files changed, 324 insertions, 0 deletions
diff --git a/kernel/arch/xtensa/include/asm/atomic.h b/kernel/arch/xtensa/include/asm/atomic.h new file mode 100644 index 000000000..00b7d46b3 --- /dev/null +++ b/kernel/arch/xtensa/include/asm/atomic.h @@ -0,0 +1,324 @@ +/* + * include/asm-xtensa/atomic.h + * + * Atomic operations that C can't guarantee us. Useful for resource counting.. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2001 - 2008 Tensilica Inc. + */ + +#ifndef _XTENSA_ATOMIC_H +#define _XTENSA_ATOMIC_H + +#include <linux/stringify.h> +#include <linux/types.h> + +#ifdef __KERNEL__ +#include <asm/processor.h> +#include <asm/cmpxchg.h> +#include <asm/barrier.h> + +#define ATOMIC_INIT(i) { (i) } + +/* + * This Xtensa implementation assumes that the right mechanism + * for exclusion is for locking interrupts to level EXCM_LEVEL. + * + * Locking interrupts looks like this: + * + * rsil a15, LOCKLEVEL + * <code> + * wsr a15, PS + * rsync + * + * Note that a15 is used here because the register allocation + * done by the compiler is not guaranteed and a window overflow + * may not occur between the rsil and wsr instructions. By using + * a15 in the rsil, the machine is guaranteed to be in a state + * where no register reference will cause an overflow. + */ + +/** + * atomic_read - read atomic variable + * @v: pointer of type atomic_t + * + * Atomically reads the value of @v. + */ +#define atomic_read(v) ACCESS_ONCE((v)->counter) + +/** + * atomic_set - set atomic variable + * @v: pointer of type atomic_t + * @i: required value + * + * Atomically sets the value of @v to @i. + */ +#define atomic_set(v,i) ((v)->counter = (i)) + +#if XCHAL_HAVE_S32C1I +#define ATOMIC_OP(op) \ +static inline void atomic_##op(int i, atomic_t * v) \ +{ \ + unsigned long tmp; \ + int result; \ + \ + __asm__ __volatile__( \ + "1: l32i %1, %3, 0\n" \ + " wsr %1, scompare1\n" \ + " " #op " %0, %1, %2\n" \ + " s32c1i %0, %3, 0\n" \ + " bne %0, %1, 1b\n" \ + : "=&a" (result), "=&a" (tmp) \ + : "a" (i), "a" (v) \ + : "memory" \ + ); \ +} \ + +#define ATOMIC_OP_RETURN(op) \ +static inline int atomic_##op##_return(int i, atomic_t * v) \ +{ \ + unsigned long tmp; \ + int result; \ + \ + __asm__ __volatile__( \ + "1: l32i %1, %3, 0\n" \ + " wsr %1, scompare1\n" \ + " " #op " %0, %1, %2\n" \ + " s32c1i %0, %3, 0\n" \ + " bne %0, %1, 1b\n" \ + " " #op " %0, %0, %2\n" \ + : "=&a" (result), "=&a" (tmp) \ + : "a" (i), "a" (v) \ + : "memory" \ + ); \ + \ + return result; \ +} + +#else /* XCHAL_HAVE_S32C1I */ + +#define ATOMIC_OP(op) \ +static inline void atomic_##op(int i, atomic_t * v) \ +{ \ + unsigned int vval; \ + \ + __asm__ __volatile__( \ + " rsil a15, "__stringify(LOCKLEVEL)"\n"\ + " l32i %0, %2, 0\n" \ + " " #op " %0, %0, %1\n" \ + " s32i %0, %2, 0\n" \ + " wsr a15, ps\n" \ + " rsync\n" \ + : "=&a" (vval) \ + : "a" (i), "a" (v) \ + : "a15", "memory" \ + ); \ +} \ + +#define ATOMIC_OP_RETURN(op) \ +static inline int atomic_##op##_return(int i, atomic_t * v) \ +{ \ + unsigned int vval; \ + \ + __asm__ __volatile__( \ + " rsil a15,"__stringify(LOCKLEVEL)"\n" \ + " l32i %0, %2, 0\n" \ + " " #op " %0, %0, %1\n" \ + " s32i %0, %2, 0\n" \ + " wsr a15, ps\n" \ + " rsync\n" \ + : "=&a" (vval) \ + : "a" (i), "a" (v) \ + : "a15", "memory" \ + ); \ + \ + return vval; \ +} + +#endif /* XCHAL_HAVE_S32C1I */ + +#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op) + +ATOMIC_OPS(add) +ATOMIC_OPS(sub) + +#undef ATOMIC_OPS +#undef ATOMIC_OP_RETURN +#undef ATOMIC_OP + +/** + * atomic_sub_and_test - subtract value from variable and test result + * @i: integer value to subtract + * @v: pointer of type atomic_t + * + * Atomically subtracts @i from @v and returns + * true if the result is zero, or false for all + * other cases. + */ +#define atomic_sub_and_test(i,v) (atomic_sub_return((i),(v)) == 0) + +/** + * atomic_inc - increment atomic variable + * @v: pointer of type atomic_t + * + * Atomically increments @v by 1. + */ +#define atomic_inc(v) atomic_add(1,(v)) + +/** + * atomic_inc - increment atomic variable + * @v: pointer of type atomic_t + * + * Atomically increments @v by 1. + */ +#define atomic_inc_return(v) atomic_add_return(1,(v)) + +/** + * atomic_dec - decrement atomic variable + * @v: pointer of type atomic_t + * + * Atomically decrements @v by 1. + */ +#define atomic_dec(v) atomic_sub(1,(v)) + +/** + * atomic_dec_return - decrement atomic variable + * @v: pointer of type atomic_t + * + * Atomically decrements @v by 1. + */ +#define atomic_dec_return(v) atomic_sub_return(1,(v)) + +/** + * atomic_dec_and_test - decrement and test + * @v: pointer of type atomic_t + * + * Atomically decrements @v by 1 and + * returns true if the result is 0, or false for all other + * cases. + */ +#define atomic_dec_and_test(v) (atomic_sub_return(1,(v)) == 0) + +/** + * atomic_inc_and_test - increment and test + * @v: pointer of type atomic_t + * + * Atomically increments @v by 1 + * and returns true if the result is zero, or false for all + * other cases. + */ +#define atomic_inc_and_test(v) (atomic_add_return(1,(v)) == 0) + +/** + * atomic_add_negative - add and test if negative + * @v: pointer of type atomic_t + * @i: integer value to add + * + * Atomically adds @i to @v and returns true + * if the result is negative, or false when + * result is greater than or equal to zero. + */ +#define atomic_add_negative(i,v) (atomic_add_return((i),(v)) < 0) + +#define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n))) +#define atomic_xchg(v, new) (xchg(&((v)->counter), new)) + +/** + * __atomic_add_unless - add unless the number is a given value + * @v: pointer of type atomic_t + * @a: the amount to add to v... + * @u: ...unless v is equal to u. + * + * Atomically adds @a to @v, so long as it was not @u. + * Returns the old value of @v. + */ +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_cmpxchg((v), c, c + (a)); + if (likely(old == c)) + break; + c = old; + } + return c; +} + + +static inline void atomic_clear_mask(unsigned int mask, atomic_t *v) +{ +#if XCHAL_HAVE_S32C1I + unsigned long tmp; + int result; + + __asm__ __volatile__( + "1: l32i %1, %3, 0\n" + " wsr %1, scompare1\n" + " and %0, %1, %2\n" + " s32c1i %0, %3, 0\n" + " bne %0, %1, 1b\n" + : "=&a" (result), "=&a" (tmp) + : "a" (~mask), "a" (v) + : "memory" + ); +#else + unsigned int all_f = -1; + unsigned int vval; + + __asm__ __volatile__( + " rsil a15,"__stringify(LOCKLEVEL)"\n" + " l32i %0, %2, 0\n" + " xor %1, %4, %3\n" + " and %0, %0, %4\n" + " s32i %0, %2, 0\n" + " wsr a15, ps\n" + " rsync\n" + : "=&a" (vval), "=a" (mask) + : "a" (v), "a" (all_f), "1" (mask) + : "a15", "memory" + ); +#endif +} + +static inline void atomic_set_mask(unsigned int mask, atomic_t *v) +{ +#if XCHAL_HAVE_S32C1I + unsigned long tmp; + int result; + + __asm__ __volatile__( + "1: l32i %1, %3, 0\n" + " wsr %1, scompare1\n" + " or %0, %1, %2\n" + " s32c1i %0, %3, 0\n" + " bne %0, %1, 1b\n" + : "=&a" (result), "=&a" (tmp) + : "a" (mask), "a" (v) + : "memory" + ); +#else + unsigned int vval; + + __asm__ __volatile__( + " rsil a15,"__stringify(LOCKLEVEL)"\n" + " l32i %0, %2, 0\n" + " or %0, %0, %1\n" + " s32i %0, %2, 0\n" + " wsr a15, ps\n" + " rsync\n" + : "=&a" (vval) + : "a" (mask), "a" (v) + : "a15", "memory" + ); +#endif +} + +#endif /* __KERNEL__ */ + +#endif /* _XTENSA_ATOMIC_H */ |