Re: [PATCH] x86: Don't use dl_x86_cpu_features in cacheinfo.c

["H.J. Lu" <hjl dot tools at gmail dot com>]

On Wed, May 24, 2017 at 1:09 PM, H.J. Lu <hongjiu.lu@intel.com> wrote:
> Since cpu_features is available, use it instead of dl_x86_cpu_features.
>
> Any comments?

Any objections?

> H.J.
> ---
>         * sysdeps/x86/cacheinfo.c (intel_check_word): Accept cpu_features
>         and use it instead of dl_x86_cpu_features.
>         (handle_intel): Replace maxidx with cpu_features.  Pass
>         cpu_features to intel_check_word.
>         (__cache_sysconf): Pass cpu_features to handle_intel.
>         (init_cacheinfo): Likewise.  Use cpu_features instead of
>         dl_x86_cpu_features.
> ---
>  sysdeps/x86/cacheinfo.c | 37 ++++++++++++++++++++++---------------
>  1 file changed, 22 insertions(+), 15 deletions(-)
>
> diff --git a/sysdeps/x86/cacheinfo.c b/sysdeps/x86/cacheinfo.c
> index 321fbb6..a46dd4d 100644
> --- a/sysdeps/x86/cacheinfo.c
> +++ b/sysdeps/x86/cacheinfo.c
> @@ -126,7 +126,8 @@ intel_02_known_compare (const void *p1, const void *p2)
>  static long int
>  __attribute__ ((noinline))
>  intel_check_word (int name, unsigned int value, bool *has_level_2,
> -                 bool *no_level_2_or_3)
> +                 bool *no_level_2_or_3,
> +                 const struct cpu_features *cpu_features)
>  {
>    if ((value & 0x80000000) != 0)
>      /* The register value is reserved.  */
> @@ -204,8 +205,8 @@ intel_check_word (int name, unsigned int value, bool *has_level_2,
>               /* Intel reused this value.  For family 15, model 6 it
>                  specifies the 3rd level cache.  Otherwise the 2nd
>                  level cache.  */
> -             unsigned int family = GLRO(dl_x86_cpu_features).family;
> -             unsigned int model = GLRO(dl_x86_cpu_features).model;
> +             unsigned int family = cpu_features->family;
> +             unsigned int model = cpu_features->model;
>
>               if (family == 15 && model == 6)
>                 {
> @@ -255,8 +256,10 @@ intel_check_word (int name, unsigned int value, bool *has_level_2,
>
>
>  static long int __attribute__ ((noinline))
> -handle_intel (int name, unsigned int maxidx)
> +handle_intel (int name, const struct cpu_features *cpu_features)
>  {
> +  unsigned int maxidx = cpu_features->max_cpuid;
> +
>    /* Return -1 for older CPUs.  */
>    if (maxidx < 2)
>      return -1;
> @@ -287,19 +290,23 @@ handle_intel (int name, unsigned int maxidx)
>         }
>
>        /* Process the individual registers' value.  */
> -      result = intel_check_word (name, eax, &has_level_2, &no_level_2_or_3);
> +      result = intel_check_word (name, eax, &has_level_2,
> +                                &no_level_2_or_3, cpu_features);
>        if (result != 0)
>         return result;
>
> -      result = intel_check_word (name, ebx, &has_level_2, &no_level_2_or_3);
> +      result = intel_check_word (name, ebx, &has_level_2,
> +                                &no_level_2_or_3, cpu_features);
>        if (result != 0)
>         return result;
>
> -      result = intel_check_word (name, ecx, &has_level_2, &no_level_2_or_3);
> +      result = intel_check_word (name, ecx, &has_level_2,
> +                                &no_level_2_or_3, cpu_features);
>        if (result != 0)
>         return result;
>
> -      result = intel_check_word (name, edx, &has_level_2, &no_level_2_or_3);
> +      result = intel_check_word (name, edx, &has_level_2,
> +                                &no_level_2_or_3, cpu_features);
>        if (result != 0)
>         return result;
>      }
> @@ -437,7 +444,7 @@ __cache_sysconf (int name)
>    const struct cpu_features *cpu_features = __get_cpu_features ();
>
>    if (cpu_features->kind == arch_kind_intel)
> -    return handle_intel (name, cpu_features->max_cpuid);
> +    return handle_intel (name, cpu_features);
>
>    if (cpu_features->kind == arch_kind_amd)
>      return handle_amd (name);
> @@ -494,14 +501,14 @@ init_cacheinfo (void)
>
>    if (cpu_features->kind == arch_kind_intel)
>      {
> -      data = handle_intel (_SC_LEVEL1_DCACHE_SIZE, max_cpuid);
> +      data = handle_intel (_SC_LEVEL1_DCACHE_SIZE, cpu_features);
>
> -      long int core = handle_intel (_SC_LEVEL2_CACHE_SIZE, max_cpuid);
> +      long int core = handle_intel (_SC_LEVEL2_CACHE_SIZE, cpu_features);
>        bool inclusive_cache = true;
>
>        /* Try L3 first.  */
>        level  = 3;
> -      shared = handle_intel (_SC_LEVEL3_CACHE_SIZE, max_cpuid);
> +      shared = handle_intel (_SC_LEVEL3_CACHE_SIZE, cpu_features);
>
>        /* Number of logical processors sharing L2 cache.  */
>        int threads_l2;
> @@ -531,8 +538,8 @@ init_cacheinfo (void)
>              highest cache level.  */
>           if (max_cpuid >= 4)
>             {
> -             unsigned int family = GLRO(dl_x86_cpu_features).family;
> -             unsigned int model = GLRO(dl_x86_cpu_features).model;
> +             unsigned int family = cpu_features->family;
> +             unsigned int model = cpu_features->model;
>
>               int i = 0;
>
> @@ -675,7 +682,7 @@ intel_bug_no_cache_info:
>                  level.  */
>
>               threads
> -               = ((GLRO(dl_x86_cpu_features).cpuid[COMMON_CPUID_INDEX_1].ebx
> +               = ((cpu_features->cpuid[COMMON_CPUID_INDEX_1].ebx
>                     >> 16) & 0xff);
>             }
>
> --
> 2.9.4
>



-- 
H.J.