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From: "H.J. Lu" <hjl.tools@gmail.com>
To: mayshao-oc <mayshao-oc@zhaoxin.com>
Cc: GNU C Library <libc-alpha@sourceware.org>,
	"Carlos O'Donell" <carlos@redhat.com>,
	Florian Weimer <fw@deneb.enyo.de>,
	"Qiyuan Wang(BJ-RD)" <QiyuanWang@zhaoxin.com>,
	 "Herry Yang(BJ-RD)" <HerryYang@zhaoxin.com>,
	"Ricky Li(BJ-RD)" <RickyLi@zhaoxin.com>
Subject: Re: [PATCH v3 2/3] x86: Add cache information support for Zhaoxin processors
Date: Fri, 24 Apr 2020 05:53:03 -0700	[thread overview]
Message-ID: <CAMe9rOodWBhXsgpRfUHdsmyZEXEUYqQz8j-08bpS4uA2+az48w@mail.gmail.com> (raw)
In-Reply-To: <1587731372-9324-3-git-send-email-mayshao-oc@zhaoxin.com>

On Fri, Apr 24, 2020 at 5:29 AM mayshao-oc <mayshao-oc@zhaoxin.com> wrote:
>
> From: mayshao <mayshao-oc@zhaoxin.com>
>
> To obtain Zhaoxin CPU cache information, add a new function
> handle_zhaoxin().
>
> Add a new function get_common_info() that extracts the code
> in init_cacheinfo() to get the value of the variable shared,
> threads.
>
> Add Zhaoxin branch in init_cacheinfo() for initializing variables,
> such as __x86_shared_cache_size.
> ---
>  sysdeps/x86/cacheinfo.c | 477 ++++++++++++++++++++++++++++--------------------
>  1 file changed, 281 insertions(+), 196 deletions(-)
>
> diff --git a/sysdeps/x86/cacheinfo.c b/sysdeps/x86/cacheinfo.c
> index e3e8ef2..14c6094 100644
> --- a/sysdeps/x86/cacheinfo.c
> +++ b/sysdeps/x86/cacheinfo.c
> @@ -436,6 +436,57 @@ handle_amd (int name)
>  }
>
>
> +static long int __attribute__ ((noinline))
> +handle_zhaoxin (int name)
> +{
> +  unsigned int eax;
> +  unsigned int ebx;
> +  unsigned int ecx;
> +  unsigned int edx;
> +
> +  int folded_rel_name = (M(name) / 3) * 3;
> +
> +  unsigned int round = 0;
> +  while (1)
> +    {
> +      __cpuid_count (4, round, eax, ebx, ecx, edx);
> +
> +      enum { null = 0, data = 1, inst = 2, uni = 3 } type = eax & 0x1f;
> +      if (type == null)
> +        break;
> +
> +      unsigned int level = (eax >> 5) & 0x7;
> +
> +      if ((level == 1 && type == data
> +        && folded_rel_name == M(_SC_LEVEL1_DCACHE_SIZE))
> +        || (level == 1 && type == inst
> +            && folded_rel_name == M(_SC_LEVEL1_ICACHE_SIZE))
> +        || (level == 2 && folded_rel_name == M(_SC_LEVEL2_CACHE_SIZE))
> +        || (level == 3 && folded_rel_name == M(_SC_LEVEL3_CACHE_SIZE)))
> +        {
> +          unsigned int offset = M(name) - folded_rel_name;
> +
> +          if (offset == 0)
> +            /* Cache size.  */
> +            return (((ebx >> 22) + 1)
> +                * (((ebx >> 12) & 0x3ff) + 1)
> +                * ((ebx & 0xfff) + 1)
> +                * (ecx + 1));
> +          if (offset == 1)
> +            return (ebx >> 22) + 1;
> +
> +          assert (offset == 2);
> +          return (ebx & 0xfff) + 1;
> +        }
> +
> +      ++round;
> +    }
> +
> +  /* Nothing found.  */
> +  return 0;
> +}
> +
> +
>  /* Get the value of the system variable NAME.  */
>  long int
>  attribute_hidden
> @@ -449,6 +500,9 @@ __cache_sysconf (int name)
>    if (cpu_features->basic.kind == arch_kind_amd)
>      return handle_amd (name);
>
> +  if (cpu_features->basic.kind == arch_kind_zhaoxin)
> +    return handle_zhaoxin (name);
> +
>    // XXX Fill in more vendors.
>
>    /* CPU not known, we have no information.  */
> @@ -483,6 +537,223 @@ int __x86_prefetchw attribute_hidden;
>
>
>  static void
> +get_common_info (long int *shared_ptr, unsigned int *threads_ptr,
> +                long int core)

get_common_cache_info

> +{
> +  unsigned int eax;
> +  unsigned int ebx;
> +  unsigned int ecx;
> +  unsigned int edx;
> +
> +  /* Number of logical processors sharing L2 cache.  */
> +  int threads_l2;
> +
> +  /* Number of logical processors sharing L3 cache.  */
> +  int threads_l3;
> +
> +  const struct cpu_features *cpu_features = __get_cpu_features ();
> +  int max_cpuid = cpu_features->basic.max_cpuid;
> +  unsigned int family = cpu_features->basic.family;
> +  unsigned int model = cpu_features->basic.model;
> +  long int shared = *shared_ptr;
> +  unsigned int threads = *threads_ptr;
> +  bool inclusive_cache = true;
> +  bool ignore_leaf_b = false;

Change to support_count_mask.

> +
> +  /* Try L3 first.  */
> +  unsigned int level = 3;
> +
> +  if (cpu_features->basic.kind == arch_kind_zhaoxin && family == 6)
> +    ignore_leaf_b = true;
> +
> +  if (shared <= 0)
> +    {
> +      /* Try L2 otherwise.  */
> +      level  = 2;
> +      shared = core;
> +      threads_l2 = 0;
> +      threads_l3 = -1;
> +    }
> +  else
> +    {
> +      threads_l2 = 0;
> +      threads_l3 = 0;
> +    }
> +
> +  /* A value of 0 for the HTT bit indicates there is only a single
> +     logical processor.  */
> +  if (HAS_CPU_FEATURE (HTT))
> +    {
> +      /* Figure out the number of logical threads that share the
> +         highest cache level.  */
> +      if (max_cpuid >= 4)
> +        {
> +          int i = 0;
> +
> +          /* Query until cache level 2 and 3 are enumerated.  */
> +          int check = 0x1 | (threads_l3 == 0) << 1;
> +          do
> +            {
> +              __cpuid_count (4, i++, eax, ebx, ecx, edx);
> +
> +              /* There seems to be a bug in at least some Pentium Ds
> +                 which sometimes fail to iterate all cache parameters.
> +                 Do not loop indefinitely here, stop in this case and
> +                 assume there is no such information.  */
> +              if ((eax & 0x1f) == 0
> +                   && cpu_features->basic.kind == arch_kind_intel)

Check arch_kind_intel first.

> +                goto intel_bug_no_cache_info;
> +
> +              switch ((eax >> 5) & 0x7)
> +                {
> +                  default:
> +                    break;
> +                  case 2:
> +                    if ((check & 0x1))
> +                      {
> +                        /* Get maximum number of logical processors
> +                           sharing L2 cache.  */
> +                        threads_l2 = (eax >> 14) & 0x3ff;
> +                        check &= ~0x1;
> +                      }
> +                    break;
> +                  case 3:
> +                    if ((check & (0x1 << 1)))
> +                      {
> +                        /* Get maximum number of logical processors
> +                           sharing L3 cache.  */
> +                        threads_l3 = (eax >> 14) & 0x3ff;
> +
> +                        /* Check if L2 and L3 caches are inclusive.  */
> +                        inclusive_cache = (edx & 0x2) != 0;
> +                        check &= ~(0x1 << 1);
> +                      }
> +                    break;
> +                }
> +            }
> +          while (check);
> +
> +          /* If max_cpuid >= 11, THREADS_L2/THREADS_L3 are the maximum
> +             numbers of addressable IDs for logical processors sharing
> +             the cache, instead of the maximum number of threads
> +             sharing the cache.  */
> +          if ((max_cpuid >= 11) && (!ignore_leaf_b))

Drop unnecessary ().

> +            {
> +              /* Find the number of logical processors shipped in
> +                 one core and apply count mask.  */
> +              i = 0;
> +
> +              /* Count SMT only if there is L3 cache.  Always count
> +                 core if there is no L3 cache.  */
> +              int count = ((threads_l2 > 0 && level == 3)
> +                           | ((threads_l3 > 0
> +                               || (threads_l2 > 0 && level == 2)) << 1));
> +
> +              while (count)
> +                {
> +                  __cpuid_count (11, i++, eax, ebx, ecx, edx);
> +
> +                  int shipped = ebx & 0xff;
> +                  int type = ecx & 0xff00;
> +                  if (shipped == 0 || type == 0)
> +                    break;
> +                  else if (type == 0x100)
> +                    {
> +                      /* Count SMT.  */
> +                      if ((count & 0x1))
> +                        {
> +                          int count_mask;
> +
> +                          /* Compute count mask.  */
> +                          asm ("bsr %1, %0"
> +                               : "=r" (count_mask) : "g" (threads_l2));
> +                          count_mask = ~(-1 << (count_mask + 1));
> +                          threads_l2 = (shipped - 1) & count_mask;
> +                          count &= ~0x1;
> +                        }
> +                    }
> +                  else if (type == 0x200)
> +                    {
> +                      /* Count core.  */
> +                      if ((count & (0x1 << 1)))
> +                        {
> +                          int count_mask;
> +                          int threads_core
> +                            = (level == 2 ? threads_l2 : threads_l3);
> +
> +                          /* Compute count mask.  */
> +                          asm ("bsr %1, %0"
> +                               : "=r" (count_mask) : "g" (threads_core));
> +                          count_mask = ~(-1 << (count_mask + 1));
> +                          threads_core = (shipped - 1) & count_mask;
> +                          if (level == 2)
> +                            threads_l2 = threads_core;
> +                          else
> +                            threads_l3 = threads_core;
> +                          count &= ~(0x1 << 1);
> +                        }
> +                    }
> +                }
> +            }
> +          if (threads_l2 > 0)
> +            threads_l2 += 1;
> +          if (threads_l3 > 0)
> +            threads_l3 += 1;
> +          if (level == 2)
> +            {
> +              if (threads_l2)
> +                {
> +                  threads = threads_l2;
> +                  if (threads > 2 && family == 6
> +                     && cpu_features->basic.kind == arch_kind_intel)

Check arch_kind_intel first.  Put each condition on a separate line.

> +                    switch (model)
> +                      {
> +                        case 0x37:
> +                        case 0x4a:
> +                        case 0x4d:
> +                        case 0x5a:
> +                        case 0x5d:
> +                          /* Silvermont has L2 cache shared by 2 cores.  */
> +                          threads = 2;
> +                          break;
> +                        default:
> +                          break;
> +                      }
> +                }
> +            }
> +          else if (threads_l3)
> +            threads = threads_l3;
> +        }
> +      else
> +        {
> +intel_bug_no_cache_info:
> +          /* Assume that all logical threads share the highest cache
> +             level.  */
> +          threads
> +            = ((cpu_features->cpuid[COMMON_CPUID_INDEX_1].ebx
> +                >> 16) & 0xff);
> +        }
> +
> +        /* Cap usage of highest cache level to the number of supported
> +           threads.  */
> +        if (shared > 0 && threads > 0)
> +          shared /= threads;
> +    }
> +
> +  /* Account for non-inclusive L2 and L3 caches.  */
> +  if (!inclusive_cache)
> +    {
> +      if (threads_l2 > 0)
> +        core /= threads_l2;
> +      shared += core;
> +    }
> +
> +  *shared_ptr = shared;
> +  *threads_ptr = threads;
> +}
> +
> +
> +static void
>  __attribute__((constructor))
>  init_cacheinfo (void)
>  {
> @@ -494,211 +765,25 @@ init_cacheinfo (void)
>    int max_cpuid_ex;
>    long int data = -1;
>    long int shared = -1;
> -  unsigned int level;
> +  long int core;
>    unsigned int threads = 0;
>    const struct cpu_features *cpu_features = __get_cpu_features ();
> -  int max_cpuid = cpu_features->basic.max_cpuid;
>
>    if (cpu_features->basic.kind == arch_kind_intel)
>      {
>        data = handle_intel (_SC_LEVEL1_DCACHE_SIZE, cpu_features);
> -
> -      long int core = handle_intel (_SC_LEVEL2_CACHE_SIZE, cpu_features);
> -      bool inclusive_cache = true;
> -
> -      /* Try L3 first.  */
> -      level  = 3;
> +      core = handle_intel (_SC_LEVEL2_CACHE_SIZE, cpu_features);
>        shared = handle_intel (_SC_LEVEL3_CACHE_SIZE, cpu_features);
>
> -      /* Number of logical processors sharing L2 cache.  */
> -      int threads_l2;
> -
> -      /* Number of logical processors sharing L3 cache.  */
> -      int threads_l3;
> -
> -      if (shared <= 0)
> -       {
> -         /* Try L2 otherwise.  */
> -         level  = 2;
> -         shared = core;
> -         threads_l2 = 0;
> -         threads_l3 = -1;
> -       }
> -      else
> -       {
> -         threads_l2 = 0;
> -         threads_l3 = 0;
> -       }
> -
> -      /* A value of 0 for the HTT bit indicates there is only a single
> -        logical processor.  */
> -      if (HAS_CPU_FEATURE (HTT))
> -       {
> -         /* Figure out the number of logical threads that share the
> -            highest cache level.  */
> -         if (max_cpuid >= 4)
> -           {
> -             unsigned int family = cpu_features->basic.family;
> -             unsigned int model = cpu_features->basic.model;
> -
> -             int i = 0;
> -
> -             /* Query until cache level 2 and 3 are enumerated.  */
> -             int check = 0x1 | (threads_l3 == 0) << 1;
> -             do
> -               {
> -                 __cpuid_count (4, i++, eax, ebx, ecx, edx);
> -
> -                 /* There seems to be a bug in at least some Pentium Ds
> -                    which sometimes fail to iterate all cache parameters.
> -                    Do not loop indefinitely here, stop in this case and
> -                    assume there is no such information.  */
> -                 if ((eax & 0x1f) == 0)
> -                   goto intel_bug_no_cache_info;
> -
> -                 switch ((eax >> 5) & 0x7)
> -                   {
> -                   default:
> -                     break;
> -                   case 2:
> -                     if ((check & 0x1))
> -                       {
> -                         /* Get maximum number of logical processors
> -                            sharing L2 cache.  */
> -                         threads_l2 = (eax >> 14) & 0x3ff;
> -                         check &= ~0x1;
> -                       }
> -                     break;
> -                   case 3:
> -                     if ((check & (0x1 << 1)))
> -                       {
> -                         /* Get maximum number of logical processors
> -                            sharing L3 cache.  */
> -                         threads_l3 = (eax >> 14) & 0x3ff;
> -
> -                         /* Check if L2 and L3 caches are inclusive.  */
> -                         inclusive_cache = (edx & 0x2) != 0;
> -                         check &= ~(0x1 << 1);
> -                       }
> -                     break;
> -                   }
> -               }
> -             while (check);
> -
> -             /* If max_cpuid >= 11, THREADS_L2/THREADS_L3 are the maximum
> -                numbers of addressable IDs for logical processors sharing
> -                the cache, instead of the maximum number of threads
> -                sharing the cache.  */
> -             if (max_cpuid >= 11)
> -               {
> -                 /* Find the number of logical processors shipped in
> -                    one core and apply count mask.  */
> -                 i = 0;
> -
> -                 /* Count SMT only if there is L3 cache.  Always count
> -                    core if there is no L3 cache.  */
> -                 int count = ((threads_l2 > 0 && level == 3)
> -                              | ((threads_l3 > 0
> -                                  || (threads_l2 > 0 && level == 2)) << 1));
> -
> -                 while (count)
> -                   {
> -                     __cpuid_count (11, i++, eax, ebx, ecx, edx);
> -
> -                     int shipped = ebx & 0xff;
> -                     int type = ecx & 0xff00;
> -                     if (shipped == 0 || type == 0)
> -                       break;
> -                     else if (type == 0x100)
> -                       {
> -                         /* Count SMT.  */
> -                         if ((count & 0x1))
> -                           {
> -                             int count_mask;
> -
> -                             /* Compute count mask.  */
> -                             asm ("bsr %1, %0"
> -                                  : "=r" (count_mask) : "g" (threads_l2));
> -                             count_mask = ~(-1 << (count_mask + 1));
> -                             threads_l2 = (shipped - 1) & count_mask;
> -                             count &= ~0x1;
> -                           }
> -                       }
> -                     else if (type == 0x200)
> -                       {
> -                         /* Count core.  */
> -                         if ((count & (0x1 << 1)))
> -                           {
> -                             int count_mask;
> -                             int threads_core
> -                               = (level == 2 ? threads_l2 : threads_l3);
> -
> -                             /* Compute count mask.  */
> -                             asm ("bsr %1, %0"
> -                                  : "=r" (count_mask) : "g" (threads_core));
> -                             count_mask = ~(-1 << (count_mask + 1));
> -                             threads_core = (shipped - 1) & count_mask;
> -                             if (level == 2)
> -                               threads_l2 = threads_core;
> -                             else
> -                               threads_l3 = threads_core;
> -                             count &= ~(0x1 << 1);
> -                           }
> -                       }
> -                   }
> -               }
> -             if (threads_l2 > 0)
> -               threads_l2 += 1;
> -             if (threads_l3 > 0)
> -               threads_l3 += 1;
> -             if (level == 2)
> -               {
> -                 if (threads_l2)
> -                   {
> -                     threads = threads_l2;
> -                     if (threads > 2 && family == 6)
> -                       switch (model)
> -                         {
> -                         case 0x37:
> -                         case 0x4a:
> -                         case 0x4d:
> -                         case 0x5a:
> -                         case 0x5d:
> -                           /* Silvermont has L2 cache shared by 2 cores.  */
> -                           threads = 2;
> -                           break;
> -                         default:
> -                           break;
> -                         }
> -                   }
> -               }
> -             else if (threads_l3)
> -               threads = threads_l3;
> -           }
> -         else
> -           {
> -intel_bug_no_cache_info:
> -             /* Assume that all logical threads share the highest cache
> -                level.  */
> -
> -             threads
> -               = ((cpu_features->cpuid[COMMON_CPUID_INDEX_1].ebx
> -                   >> 16) & 0xff);
> -           }
> -
> -         /* Cap usage of highest cache level to the number of supported
> -            threads.  */
> -         if (shared > 0 && threads > 0)
> -           shared /= threads;
> -       }
> +      get_common_info (&shared, &threads, core);
> +    }
> +  else if (cpu_features->basic.kind == arch_kind_zhaoxin)
> +    {
> +      data = handle_zhaoxin (_SC_LEVEL1_DCACHE_SIZE);
> +      core = handle_zhaoxin (_SC_LEVEL2_CACHE_SIZE);
> +      shared = handle_zhaoxin (_SC_LEVEL3_CACHE_SIZE);
>
> -      /* Account for non-inclusive L2 and L3 caches.  */
> -      if (!inclusive_cache)
> -       {
> -         if (threads_l2 > 0)
> -           core /= threads_l2;
> -         shared += core;
> -       }
> +      get_common_info (&shared, &threads, core);
>      }
>    else if (cpu_features->basic.kind == arch_kind_amd)
>      {
> --
> 2.7.4
>


-- 
H.J.

  reply	other threads:[~2020-04-24 12:53 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-24 12:29 [PATCH v3 0/3] x86: Add " mayshao-oc
2020-04-24 12:29 ` [PATCH v3 1/3] x86: Add CPU Vendor ID detection " mayshao-oc
2020-04-24 12:53   ` H.J. Lu
2020-04-24 12:29 ` [PATCH v3 2/3] x86: Add cache information " mayshao-oc
2020-04-24 12:53   ` H.J. Lu [this message]
2020-04-26  5:54     ` Mayshao-oc
2020-04-26 12:07       ` H.J. Lu
2020-04-30  5:09         ` Mayshao-oc
2020-04-30  5:15           ` H.J. Lu
2020-04-30  6:04             ` Mayshao-oc
2020-04-30 12:52               ` H.J. Lu
2020-04-30 13:22                 ` Mayshao-oc
2020-04-30 13:55                   ` H.J. Lu
2020-04-30 14:39                     ` Mayshao-oc
2020-04-30 19:10               ` Joseph Myers
2020-04-30 19:16                 ` Florian Weimer
2020-04-30 19:21                   ` H.J. Lu
2020-04-30 20:04                     ` Florian Weimer
2020-04-24 12:29 ` [PATCH v3 3/3] x86: Add the test case of __get_cpu_features " mayshao-oc
2020-04-24 12:54   ` H.J. Lu

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