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author | James Hogan <james.hogan@imgtec.com> | 2012-10-09 10:00:24 (GMT) |
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committer | James Hogan <james.hogan@imgtec.com> | 2013-03-02 20:09:50 (GMT) |
commit | 6006c0d8ce9441dd1363bf14f18a8e28d3588460 (patch) | |
tree | 786183053c89e11b3058b8a16f7953744b819340 /arch/metag/include/asm/bitops.h | |
parent | 9b802d1f43978869fcd98e92b854fd8785cefee7 (diff) | |
download | linux-6006c0d8ce9441dd1363bf14f18a8e28d3588460.tar.xz |
metag: Atomics, locks and bitops
Add header files to implement Meta hardware thread locks (used by some
other atomic operations), atomics, spinlocks, and bitops.
There are 2 main types of atomic primitives for metag (in addition to
IRQs off on UP):
- LOCK instructions provide locking between hardware threads.
- LNKGET/LNKSET instructions provide load-linked/store-conditional
operations allowing for lighter weight atomics on Meta2
LOCK instructions allow for hardware threads to acquire voluntary or
exclusive hardware thread locks:
- LOCK0 releases exclusive and voluntary lock from the running hardware
thread.
- LOCK1 acquires the voluntary hardware lock, blocking until it becomes
available.
- LOCK2 implies LOCK1, and additionally acquires the exclusive hardware
lock, blocking all other hardware threads from executing.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Diffstat (limited to 'arch/metag/include/asm/bitops.h')
-rw-r--r-- | arch/metag/include/asm/bitops.h | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/arch/metag/include/asm/bitops.h b/arch/metag/include/asm/bitops.h new file mode 100644 index 0000000..c0d0df0 --- /dev/null +++ b/arch/metag/include/asm/bitops.h @@ -0,0 +1,132 @@ +#ifndef __ASM_METAG_BITOPS_H +#define __ASM_METAG_BITOPS_H + +#include <linux/compiler.h> +#include <asm/barrier.h> +#include <asm/global_lock.h> + +/* + * clear_bit() doesn't provide any barrier for the compiler. + */ +#define smp_mb__before_clear_bit() barrier() +#define smp_mb__after_clear_bit() barrier() + +#ifdef CONFIG_SMP +/* + * These functions are the basis of our bit ops. + */ +static inline void set_bit(unsigned int bit, volatile unsigned long *p) +{ + unsigned long flags; + unsigned long mask = 1UL << (bit & 31); + + p += bit >> 5; + + __global_lock1(flags); + fence(); + *p |= mask; + __global_unlock1(flags); +} + +static inline void clear_bit(unsigned int bit, volatile unsigned long *p) +{ + unsigned long flags; + unsigned long mask = 1UL << (bit & 31); + + p += bit >> 5; + + __global_lock1(flags); + fence(); + *p &= ~mask; + __global_unlock1(flags); +} + +static inline void change_bit(unsigned int bit, volatile unsigned long *p) +{ + unsigned long flags; + unsigned long mask = 1UL << (bit & 31); + + p += bit >> 5; + + __global_lock1(flags); + fence(); + *p ^= mask; + __global_unlock1(flags); +} + +static inline int test_and_set_bit(unsigned int bit, volatile unsigned long *p) +{ + unsigned long flags; + unsigned long old; + unsigned long mask = 1UL << (bit & 31); + + p += bit >> 5; + + __global_lock1(flags); + old = *p; + if (!(old & mask)) { + fence(); + *p = old | mask; + } + __global_unlock1(flags); + + return (old & mask) != 0; +} + +static inline int test_and_clear_bit(unsigned int bit, + volatile unsigned long *p) +{ + unsigned long flags; + unsigned long old; + unsigned long mask = 1UL << (bit & 31); + + p += bit >> 5; + + __global_lock1(flags); + old = *p; + if (old & mask) { + fence(); + *p = old & ~mask; + } + __global_unlock1(flags); + + return (old & mask) != 0; +} + +static inline int test_and_change_bit(unsigned int bit, + volatile unsigned long *p) +{ + unsigned long flags; + unsigned long old; + unsigned long mask = 1UL << (bit & 31); + + p += bit >> 5; + + __global_lock1(flags); + fence(); + old = *p; + *p = old ^ mask; + __global_unlock1(flags); + + return (old & mask) != 0; +} + +#else +#include <asm-generic/bitops/atomic.h> +#endif /* CONFIG_SMP */ + +#include <asm-generic/bitops/non-atomic.h> +#include <asm-generic/bitops/find.h> +#include <asm-generic/bitops/ffs.h> +#include <asm-generic/bitops/__ffs.h> +#include <asm-generic/bitops/ffz.h> +#include <asm-generic/bitops/fls.h> +#include <asm-generic/bitops/__fls.h> +#include <asm-generic/bitops/fls64.h> +#include <asm-generic/bitops/hweight.h> +#include <asm-generic/bitops/lock.h> +#include <asm-generic/bitops/sched.h> +#include <asm-generic/bitops/le.h> +#include <asm-generic/bitops/ext2-atomic.h> + +#endif /* __ASM_METAG_BITOPS_H */ |