lkml.org 
[lkml]   [2026]   [Apr]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH] LoongArch: Refactor the Features output in show_cpuinfo()
https://lore.kernel.org/loongarch/20260228102946.4045-1-dongtai.guo@linux.dev/
https://lore.kernel.org/loongarch/20260428075231.2283151-1-maqianga@uniontech.com/T/#u

What make you modify here again and again?
Is this function ugly?
Is this function has bugs?
Or for some other reasons?


Huacai

On Tue, Apr 28, 2026 at 3:53 PM Qiang Ma <maqianga@uniontech.com> wrote:
>
> 1. Adds an hwcap_str[] mapping table, using KERNEL_HWCAP(x)
> (i.e., const_ilog2(HWCAP_LOONGARCH_x)) to map HWCAP bits
> to corresponding strings;
> 2. In show_cpuinfo(), iterates through hwcap_str in a loop,
> checks the bitmap of elf_hwcap, and prints the corresponding
> feature names;
> 3. Maintains the original output semantics (still printing
> the same feature names) to facilitate adding new CPU features
> in the future.
>
> Signed-off-by: Qiang Ma <maqianga@uniontech.com>
> ---
> arch/loongarch/kernel/proc.c | 60 ++++++++++++++++--------------------
> 1 file changed, 26 insertions(+), 34 deletions(-)
>
> diff --git a/arch/loongarch/kernel/proc.c b/arch/loongarch/kernel/proc.c
> index d4ce5b585453..1188bffd66b6 100644
> --- a/arch/loongarch/kernel/proc.c
> +++ b/arch/loongarch/kernel/proc.c
> @@ -12,9 +12,32 @@
> #include <asm/idle.h>
> #include <asm/processor.h>
> #include <asm/time.h>
> +#include <asm/cpufeature.h>
> +
> +#define KERNEL_HWCAP(x) const_ilog2(HWCAP_LOONGARCH_ ## x)
> +static const char *const hwcap_str[] = {
> + [KERNEL_HWCAP(CPUCFG)] = "cpucfg",
> + [KERNEL_HWCAP(LAM)] = "lam",
> + [KERNEL_HWCAP(LAM_BH)] = "lam_bh",
> + [KERNEL_HWCAP(UAL)] = "ual",
> + [KERNEL_HWCAP(FPU)] = "fpu",
> + [KERNEL_HWCAP(LSX)] = "lsx",
> + [KERNEL_HWCAP(LASX)] = "lasx",
> + [KERNEL_HWCAP(CRC32)] = "crc32",
> + [KERNEL_HWCAP(COMPLEX)] = "complex",
> + [KERNEL_HWCAP(CRYPTO)] = "crypto",
> + [KERNEL_HWCAP(LVZ)] = "lvz",
> + [KERNEL_HWCAP(LBT_X86)] = "lbt_x86",
> + [KERNEL_HWCAP(LBT_ARM)] = "lbt_arm",
> + [KERNEL_HWCAP(LBT_MIPS)] = "lbt_mips",
> + [KERNEL_HWCAP(PTW)] = "ptw",
> + [KERNEL_HWCAP(LSPW)] = "lspw",
> + [KERNEL_HWCAP(SCQ)] = "scq",
> +};
>
> static int show_cpuinfo(struct seq_file *m, void *v)
> {
> + unsigned int i;
> unsigned long n = (unsigned long) v - 1;
> unsigned int isa = cpu_data[n].isa_level;
> unsigned int prid = cpu_data[n].processor_id;
> @@ -60,40 +83,9 @@ static int show_cpuinfo(struct seq_file *m, void *v)
> seq_puts(m, "\n");
>
> seq_puts(m, "Features\t\t:");
> - if (cpu_has_cpucfg)
> - seq_puts(m, " cpucfg");
> - if (cpu_has_lam)
> - seq_puts(m, " lam");
> - if (cpu_has_lam_bh)
> - seq_puts(m, " lam_bh");
> - if (cpu_has_scq)
> - seq_puts(m, " scq");
> - if (cpu_has_ual)
> - seq_puts(m, " ual");
> - if (cpu_has_fpu)
> - seq_puts(m, " fpu");
> - if (cpu_has_lsx)
> - seq_puts(m, " lsx");
> - if (cpu_has_lasx)
> - seq_puts(m, " lasx");
> - if (cpu_has_crc32)
> - seq_puts(m, " crc32");
> - if (cpu_has_complex)
> - seq_puts(m, " complex");
> - if (cpu_has_crypto)
> - seq_puts(m, " crypto");
> - if (cpu_has_ptw)
> - seq_puts(m, " ptw");
> - if (cpu_has_lspw)
> - seq_puts(m, " lspw");
> - if (cpu_has_lvz)
> - seq_puts(m, " lvz");
> - if (cpu_has_lbt_x86)
> - seq_puts(m, " lbt_x86");
> - if (cpu_has_lbt_arm)
> - seq_puts(m, " lbt_arm");
> - if (cpu_has_lbt_mips)
> - seq_puts(m, " lbt_mips");
> + for (i = 0; i < ARRAY_SIZE(hwcap_str); i++)
> + if (elf_hwcap & (1 << i))
> + seq_printf(m, " %s", hwcap_str[i]);
> seq_puts(m, "\n");
>
> seq_printf(m, "Hardware Watchpoint\t: %s", str_yes_no(cpu_has_watch));
> --
> 2.20.1
>

\
 
 \ /
  Last update: 2026-04-28 12:12    [W:0.104 / U:7.567 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and my Meterkast|Read the blog