Re: [PATCH V4 07/22] LoongArch: Add atomic/locking headers

[Peter Zijlstra]

On Mon, Sep 27, 2021 at 02:42:44PM +0800, Huacai Chen wrote:
> diff --git a/arch/loongarch/include/asm/spinlock.h b/arch/loongarch/include/asm/spinlock.h
> new file mode 100644
> index 000000000000..2544ee546596
> --- /dev/null
> +++ b/arch/loongarch/include/asm/spinlock.h
> @@ -0,0 +1,12 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
> + */
> +#ifndef _ASM_SPINLOCK_H
> +#define _ASM_SPINLOCK_H
> +
> +#include <asm/processor.h>
> +#include <asm/qspinlock.h>
> +#include <asm/qrwlock.h>
> +
> +#endif /* _ASM_SPINLOCK_H */
> diff --git a/arch/loongarch/include/asm/spinlock_types.h b/arch/loongarch/include/asm/spinlock_types.h
> new file mode 100644
> index 000000000000..91f258401ef9
> --- /dev/null
> +++ b/arch/loongarch/include/asm/spinlock_types.h
> @@ -0,0 +1,11 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
> + */
> +#ifndef _ASM_SPINLOCK_TYPES_H
> +#define _ASM_SPINLOCK_TYPES_H
> +
> +#include <asm-generic/qspinlock_types.h>
> +#include <asm-generic/qrwlock_types.h>
> +
> +#endif

Also see the many lkml threads on this, is there big enough loongson to
justify qspinlock? Have you tried a ticket lock?