Re: [PATCH 3/7] util: Add cpuinfo for loongarch64

[Jiajie Chen]

On 2023/9/17 06:01, Richard Henderson wrote:
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   host/include/loongarch64/host/cpuinfo.h | 21 +++++++++++++++
>   util/cpuinfo-loongarch.c                | 35 +++++++++++++++++++++++++
>   util/meson.build                        |  2 ++
>   3 files changed, 58 insertions(+)
>   create mode 100644 host/include/loongarch64/host/cpuinfo.h
>   create mode 100644 util/cpuinfo-loongarch.c
>
> diff --git a/host/include/loongarch64/host/cpuinfo.h 
> b/host/include/loongarch64/host/cpuinfo.h
> new file mode 100644
> index 0000000000..fab664a10b
> --- /dev/null
> +++ b/host/include/loongarch64/host/cpuinfo.h
> @@ -0,0 +1,21 @@
> +/*
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + * Host specific cpu identification for LoongArch
> + */
> +
> +#ifndef HOST_CPUINFO_H
> +#define HOST_CPUINFO_H
> +
> +#define CPUINFO_ALWAYS          (1u << 0)  /* so cpuinfo is nonzero */
> +#define CPUINFO_LSX             (1u << 1)
> +
> +/* Initialized with a constructor. */
> +extern unsigned cpuinfo;
> +
> +/*
> + * We cannot rely on constructor ordering, so other constructors must
> + * use the function interface rather than the variable above.
> + */
> +unsigned cpuinfo_init(void);
> +
> +#endif /* HOST_CPUINFO_H */
> diff --git a/util/cpuinfo-loongarch.c b/util/cpuinfo-loongarch.c
> new file mode 100644
> index 0000000000..08b6d7460c
> --- /dev/null
> +++ b/util/cpuinfo-loongarch.c
> @@ -0,0 +1,35 @@
> +/*
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + * Host specific cpu identification for LoongArch.
> + */
> +
> +#include "qemu/osdep.h"
> +#include "host/cpuinfo.h"
> +
> +#ifdef CONFIG_GETAUXVAL
> +# include <sys/auxv.h>
> +#else
> +# include "elf.h"
> +#endif
> +#include <asm/hwcap.h>
> +
> +unsigned cpuinfo;
> +
> +/* Called both as constructor and (possibly) via other constructors. */
> +unsigned __attribute__((constructor)) cpuinfo_init(void)
> +{
> +    unsigned info = cpuinfo;
> +    unsigned long hwcap;
> +
> +    if (info) {
> +        return info;
> +    }
> +
> +    hwcap = qemu_getauxval(AT_HWCAP);
> +
> +    info = CPUINFO_ALWAYS;
> +    info |= (hwcap & HWCAP_LOONGARCH_LSX ? CPUINFO_LSX : 0);
> +
> +    cpuinfo = info;
> +    return info;
> +}
> diff --git a/util/meson.build b/util/meson.build
> index c4827fd70a..b136f02aa0 100644
> --- a/util/meson.build
> +++ b/util/meson.build
> @@ -112,6 +112,8 @@ if cpu == 'aarch64'
>     util_ss.add(files('cpuinfo-aarch64.c'))
>   elif cpu in ['x86', 'x86_64']
>     util_ss.add(files('cpuinfo-i386.c'))
> +elif cpu == 'loongarch64'
> +  util_ss.add(files('cpuinfo-loongarch.c'))
>   elif cpu in ['ppc', 'ppc64']
>     util_ss.add(files('cpuinfo-ppc.c'))
>   endif


Reviewed-by: Jiajie Chen <c@jia.je>