diff options
author | James Hogan <james.hogan@imgtec.com> | 2012-10-09 10:00:24 (GMT) |
---|---|---|
committer | James Hogan <james.hogan@imgtec.com> | 2013-03-02 20:09:50 (GMT) |
commit | 6006c0d8ce9441dd1363bf14f18a8e28d3588460 (patch) | |
tree | 786183053c89e11b3058b8a16f7953744b819340 /arch/metag/include/asm/cmpxchg_lnkget.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/cmpxchg_lnkget.h')
-rw-r--r-- | arch/metag/include/asm/cmpxchg_lnkget.h | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/arch/metag/include/asm/cmpxchg_lnkget.h b/arch/metag/include/asm/cmpxchg_lnkget.h new file mode 100644 index 0000000..0154e28 --- /dev/null +++ b/arch/metag/include/asm/cmpxchg_lnkget.h @@ -0,0 +1,86 @@ +#ifndef __ASM_METAG_CMPXCHG_LNKGET_H +#define __ASM_METAG_CMPXCHG_LNKGET_H + +static inline unsigned long xchg_u32(volatile u32 *m, unsigned long val) +{ + int temp, old; + + smp_mb(); + + asm volatile ( + "1: LNKGETD %1, [%2]\n" + " LNKSETD [%2], %3\n" + " DEFR %0, TXSTAT\n" + " ANDT %0, %0, #HI(0x3f000000)\n" + " CMPT %0, #HI(0x02000000)\n" + " BNZ 1b\n" +#ifdef CONFIG_METAG_LNKGET_AROUND_CACHE + " DCACHE [%2], %0\n" +#endif + : "=&d" (temp), "=&d" (old) + : "da" (m), "da" (val) + : "cc" + ); + + smp_mb(); + + return old; +} + +static inline unsigned long xchg_u8(volatile u8 *m, unsigned long val) +{ + int temp, old; + + smp_mb(); + + asm volatile ( + "1: LNKGETD %1, [%2]\n" + " LNKSETD [%2], %3\n" + " DEFR %0, TXSTAT\n" + " ANDT %0, %0, #HI(0x3f000000)\n" + " CMPT %0, #HI(0x02000000)\n" + " BNZ 1b\n" +#ifdef CONFIG_METAG_LNKGET_AROUND_CACHE + " DCACHE [%2], %0\n" +#endif + : "=&d" (temp), "=&d" (old) + : "da" (m), "da" (val & 0xff) + : "cc" + ); + + smp_mb(); + + return old; +} + +static inline unsigned long __cmpxchg_u32(volatile int *m, unsigned long old, + unsigned long new) +{ + __u32 retval, temp; + + smp_mb(); + + asm volatile ( + "1: LNKGETD %1, [%2]\n" + " CMP %1, %3\n" + " LNKSETDEQ [%2], %4\n" + " BNE 2f\n" + " DEFR %0, TXSTAT\n" + " ANDT %0, %0, #HI(0x3f000000)\n" + " CMPT %0, #HI(0x02000000)\n" + " BNZ 1b\n" +#ifdef CONFIG_METAG_LNKGET_AROUND_CACHE + " DCACHE [%2], %0\n" +#endif + "2:\n" + : "=&d" (temp), "=&da" (retval) + : "da" (m), "bd" (old), "da" (new) + : "cc" + ); + + smp_mb(); + + return retval; +} + +#endif /* __ASM_METAG_CMPXCHG_LNKGET_H */ |