* [PATCH] LoongArch: Refactor the Features output in show_cpuinfo()
@ 2026-04-28 7:52 Qiang Ma
2026-04-28 9:37 ` Huacai Chen
0 siblings, 1 reply; 4+ messages in thread
From: Qiang Ma @ 2026-04-28 7:52 UTC (permalink / raw)
To: chenhuacai, kernel; +Cc: loongarch, linux-kernel, Qiang Ma
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
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] LoongArch: Refactor the Features output in show_cpuinfo()
2026-04-28 7:52 [PATCH] LoongArch: Refactor the Features output in show_cpuinfo() Qiang Ma
@ 2026-04-28 9:37 ` Huacai Chen
2026-04-28 10:08 ` Qiang Ma
0 siblings, 1 reply; 4+ messages in thread
From: Huacai Chen @ 2026-04-28 9:37 UTC (permalink / raw)
To: Qiang Ma; +Cc: kernel, loongarch, linux-kernel
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
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] LoongArch: Refactor the Features output in show_cpuinfo()
2026-04-28 9:37 ` Huacai Chen
@ 2026-04-28 10:08 ` Qiang Ma
2026-04-28 10:30 ` Huacai Chen
0 siblings, 1 reply; 4+ messages in thread
From: Qiang Ma @ 2026-04-28 10:08 UTC (permalink / raw)
To: Huacai Chen; +Cc: kernel, loongarch, linux-kernel
在 2026/4/28 17:37, Huacai Chen 写道:
> 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?
Sorry, I didn't notice that the relevant patch had already been submitted.
> Is this function ugly?
> Is this function has bugs?
No
> Or for some other reasons?
I noticed that with the addition of new features to the LoongArch
architecture,
new features can be conveniently added without constantly needing to add
if statements, keeping the code concise.
>
>
> 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
>>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] LoongArch: Refactor the Features output in show_cpuinfo()
2026-04-28 10:08 ` Qiang Ma
@ 2026-04-28 10:30 ` Huacai Chen
0 siblings, 0 replies; 4+ messages in thread
From: Huacai Chen @ 2026-04-28 10:30 UTC (permalink / raw)
To: Qiang Ma; +Cc: kernel, loongarch, linux-kernel
On Tue, Apr 28, 2026 at 6:08 PM Qiang Ma <maqianga@uniontech.com> wrote:
>
>
> 在 2026/4/28 17:37, Huacai Chen 写道:
> > 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?
> Sorry, I didn't notice that the relevant patch had already been submitted.
> > Is this function ugly?
> > Is this function has bugs?
> No
> > Or for some other reasons?
>
> I noticed that with the addition of new features to the LoongArch
> architecture,
>
> new features can be conveniently added without constantly needing to add
> if statements, keeping the code concise.
cpuinfo are not always the same as hwcaps, stop please.
Huacai
>
> >
> >
> > 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
> >>
^ permalink raw reply [flat|nested] 4+ messages in thread
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2026-04-28 7:52 [PATCH] LoongArch: Refactor the Features output in show_cpuinfo() Qiang Ma
2026-04-28 9:37 ` Huacai Chen
2026-04-28 10:08 ` Qiang Ma
2026-04-28 10:30 ` Huacai Chen
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