This utilize the load-link/store-conditional l.lwa and l.swa instructions to implement the atomic bitops. When those instructions are not available, a fallback to the generic implementation is provided.
Signed-off-by: Stefan Kristiansson <[email protected]> --- arch/openrisc/include/asm/bitops.h | 2 +- arch/openrisc/include/asm/bitops/atomic.h | 109 ++++++++++++++++++++++++++++++ 2 files changed, 110 insertions(+), 1 deletion(-) create mode 100644 arch/openrisc/include/asm/bitops/atomic.h diff --git a/arch/openrisc/include/asm/bitops.h b/arch/openrisc/include/asm/bitops.h index 2c64f22..08271bc 100644 --- a/arch/openrisc/include/asm/bitops.h +++ b/arch/openrisc/include/asm/bitops.h @@ -52,7 +52,7 @@ #include <asm-generic/bitops/hweight.h> #include <asm-generic/bitops/lock.h> -#include <asm-generic/bitops/atomic.h> +#include <asm/bitops/atomic.h> #include <asm-generic/bitops/non-atomic.h> #include <asm-generic/bitops/le.h> #include <asm-generic/bitops/ext2-atomic.h> diff --git a/arch/openrisc/include/asm/bitops/atomic.h b/arch/openrisc/include/asm/bitops/atomic.h new file mode 100644 index 0000000..ef25cff --- /dev/null +++ b/arch/openrisc/include/asm/bitops/atomic.h @@ -0,0 +1,109 @@ +/* + * Copyright (C) 2014 Stefan Kristiansson <[email protected]> + * + * This file is licensed under the terms of the GNU General Public License + * version 2. This program is licensed "as is" without any warranty of any + * kind, whether express or implied. + */ + +#ifndef __ASM_OPENRISC_BITOPS_ATOMIC_H +#define __ASM_OPENRISC_BITOPS_ATOMIC_H + +#ifdef CONFIG_OPENRISC_HAVE_INST_LWA_SWA + +static inline void set_bit(int nr, volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + unsigned long tmp; + + __asm__ __volatile__( + "1: l.lwa %0,0(%1) \n" + " l.or %0,%0,%2 \n" + " l.swa 0(%1),%0 \n" + " l.bnf 1b \n" + " l.nop \n" + : "=&r"(tmp) + : "r"(p), "r"(mask) + : "cc", "memory"); +} + +static inline void clear_bit(int nr, volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + unsigned long tmp; + + __asm__ __volatile__( + "1: l.lwa %0,0(%1) \n" + " l.and %0,%0,%2 \n" + " l.swa 0(%1),%0 \n" + " l.bnf 1b \n" + " l.nop \n" + : "=&r"(tmp) + : "r"(p), "r"(~mask) + : "cc", "memory"); +} + +static inline void change_bit(int nr, volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + unsigned long tmp; + + __asm__ __volatile__( + "1: l.lwa %0,0(%1) \n" + " l.xor %0,%0,%2 \n" + " l.swa 0(%1),%0 \n" + " l.bnf 1b \n" + " l.nop \n" + : "=&r"(tmp) + : "r"(p), "r"(mask) + : "cc", "memory"); +} + +static inline int test_and_set_bit(int nr, volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + unsigned long old; + unsigned long tmp; + + __asm__ __volatile__( + "1: l.lwa %0,0(%2) \n" + " l.or %1,%0,%3 \n" + " l.swa 0(%2),%1 \n" + " l.bnf 1b \n" + " l.nop \n" + : "=&r"(old), "=&r"(tmp) + : "r"(p), "r"(mask) + : "cc", "memory"); + + return (old & mask) != 0; +} + +static inline int test_and_clear_bit(int nr, volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + unsigned long old; + unsigned long tmp; + + __asm__ __volatile__( + "1: l.lwa %0,0(%2) \n" + " l.and %1,%0,%3 \n" + " l.swa 0(%2),%1 \n" + " l.bnf 1b \n" + " l.nop \n" + : "=&r"(old), "=&r"(tmp) + : "r"(p), "r"(~mask) + : "cc", "memory"); + + return (old & mask) != 0; +} + +#else +#include <asm-generic/bitops/atomic.h> +#endif + +#endif /* __ASM_OPENRISC_BITOPS_ATOMIC_H */ -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
