Re: [PATCH v3 06/13] or1k: Atomics and Locking primitives

[Adhemerval Zanella <adhemerval.zanella@linaro.org>]

LGTM, thanks.

On 10/12/2021 20:34, Stafford Horne via Libc-alpha wrote:
> ---
>  sysdeps/or1k/atomic-machine.h | 79 +++++++++++++++++++++++++++++++++++
>  1 file changed, 79 insertions(+)
>  create mode 100644 sysdeps/or1k/atomic-machine.h
> 
> diff --git a/sysdeps/or1k/atomic-machine.h b/sysdeps/or1k/atomic-machine.h
> new file mode 100644
> index 0000000000..1e306ae4ef
> --- /dev/null
> +++ b/sysdeps/or1k/atomic-machine.h
> @@ -0,0 +1,79 @@
> +/* Atomic operations.  OpenRISC version.
> +   Copyright (C) 2021 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library.  If not, see
> +   <https://www.gnu.org/licenses/>.  */
> +
> +#ifndef __OR1K_ATOMIC_H_
> +#define __OR1K_ATOMIC_H_
> +
> +#include <stdint.h>
> +
> +typedef int32_t atomic32_t;
> +typedef uint32_t uatomic32_t;
> +
> +typedef intptr_t atomicptr_t;
> +typedef uintptr_t uatomicptr_t;
> +typedef intmax_t atomic_max_t;
> +typedef uintmax_t uatomic_max_t;

Sigh, these definition are used solely in only file, memusage.c.  Another thing
I will cleanup.

> +
> +#define __HAVE_64B_ATOMICS 0
> +#define USE_ATOMIC_COMPILER_BUILTINS 1
> +#define ATOMIC_EXCHANGE_USES_CAS 1
> +
> +#define __arch_compare_and_exchange_bool_8_int(mem, newval, oldval, model) \
> +  (abort (), 0)
> +
> +#define __arch_compare_and_exchange_bool_16_int(mem, newval, oldval, model) \
> +  (abort (), 0)
> +
> +#define __arch_compare_and_exchange_bool_32_int(mem, newval, oldval, model) \
> +  ({                                                                    \
> +    typeof (*mem) __oldval = (oldval);                                  \
> +    !__atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0,   \
> +				  model, __ATOMIC_RELAXED);             \
> +  })
> +
> +#define __arch_compare_and_exchange_bool_64_int(mem, newval, oldval, model) \
> +  (abort (), 0)
> +
> +#define __arch_compare_and_exchange_val_8_int(mem, newval, oldval, model) \
> +  (abort (), (__typeof (*mem)) 0)
> +
> +#define __arch_compare_and_exchange_val_16_int(mem, newval, oldval, model) \
> +  (abort (), (__typeof (*mem)) 0)
> +
> +#define __arch_compare_and_exchange_val_32_int(mem, newval, oldval, model) \
> +  ({                                                                    \
> +    typeof (*mem) __oldval = (oldval);                                  \
> +    __atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0,    \
> +				 model, __ATOMIC_RELAXED);              \
> +    __oldval;                                                           \
> +  })
> +
> +#define __arch_compare_and_exchange_val_64_int(mem, newval, oldval, model) \
> +  (abort (), (__typeof (*mem)) 0)
> +
> +#define atomic_compare_and_exchange_bool_acq(mem, new, old)		\
> +  __atomic_bool_bysize (__arch_compare_and_exchange_bool, int,		\
> +			mem, new, old, __ATOMIC_ACQUIRE)
> +
> +#define atomic_compare_and_exchange_val_acq(mem, new, old)		\
> +  __atomic_val_bysize (__arch_compare_and_exchange_val, int,		\
> +		       mem, new, old, __ATOMIC_ACQUIRE)
> +
> +#define atomic_full_barrier() ({ asm volatile ("l.msync" ::: "memory"); })

And I think we can also clean this up as well.

> +
> +#endif /* atomic-machine.h */