File amd-cacheinfo.patch of Package glibc

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File amd-cacheinfo.patch of Package glibc

From 103a469dc7755fd9e8ccf362f3dd4c55dc761908 Mon Sep 17 00:00:00 2001
From: Sajan Karumanchi <sajan.karumanchi@amd.com>
Date: Wed, 18 Jan 2023 18:29:04 +0100
Subject: [PATCH] x86: Cache computation for AMD architecture.

All AMD architectures cache details will be computed based on
__cpuid__ `0x8000_001D` and the reference to __cpuid__ `0x8000_0006` will be
zeroed out for future architectures.

Reviewed-by: Premachandra Mallappa <premachandra.mallappa@amd.com>
---
 sysdeps/x86/dl-cacheinfo.h | 204 ++++++++-----------------------------
 1 file changed, 45 insertions(+), 159 deletions(-)

Index: glibc-2.31/sysdeps/x86/cacheinfo.c
===================================================================
--- glibc-2.31.orig/sysdeps/x86/cacheinfo.c
+++ glibc-2.31/sysdeps/x86/cacheinfo.c
@@ -326,111 +326,41 @@ handle_amd (int name)
   unsigned int ebx;
   unsigned int ecx;
   unsigned int edx;
-  __cpuid (0x80000000, eax, ebx, ecx, edx);
+  unsigned int count = 0x1;
 
   /* No level 4 cache (yet).  */
   if (name > _SC_LEVEL3_CACHE_LINESIZE)
     return 0;
 
-  unsigned int fn = 0x80000005 + (name >= _SC_LEVEL2_CACHE_SIZE);
-  if (eax < fn)
-    return 0;
-
-  __cpuid (fn, eax, ebx, ecx, edx);
+  if (name >= _SC_LEVEL3_CACHE_SIZE)
+    count = 0x3;
+  else if (name >= _SC_LEVEL2_CACHE_SIZE)
+    count = 0x2;
+  else if (name >= _SC_LEVEL1_DCACHE_SIZE)
+    count = 0x0;
 
-  if (name < _SC_LEVEL1_DCACHE_SIZE)
-    {
-      name += _SC_LEVEL1_DCACHE_SIZE - _SC_LEVEL1_ICACHE_SIZE;
-      ecx = edx;
-    }
+  __cpuid_count (0x8000001D, count, eax, ebx, ecx, edx);
 
   switch (name)
     {
-    case _SC_LEVEL1_DCACHE_SIZE:
-      return (ecx >> 14) & 0x3fc00;
-
-    case _SC_LEVEL1_DCACHE_ASSOC:
-      ecx >>= 16;
-      if ((ecx & 0xff) == 0xff)
-	/* Fully associative.  */
-	return (ecx << 2) & 0x3fc00;
-      return ecx & 0xff;
-
-    case _SC_LEVEL1_DCACHE_LINESIZE:
-      return ecx & 0xff;
-
-    case _SC_LEVEL2_CACHE_SIZE:
-      return (ecx & 0xf000) == 0 ? 0 : (ecx >> 6) & 0x3fffc00;
-
-    case _SC_LEVEL2_CACHE_ASSOC:
-      switch ((ecx >> 12) & 0xf)
-	{
-	case 0:
-	case 1:
-	case 2:
-	case 4:
-	  return (ecx >> 12) & 0xf;
-	case 6:
-	  return 8;
-	case 8:
-	  return 16;
-	case 10:
-	  return 32;
-	case 11:
-	  return 48;
-	case 12:
-	  return 64;
-	case 13:
-	  return 96;
-	case 14:
-	  return 128;
-	case 15:
-	  return ((ecx >> 6) & 0x3fffc00) / (ecx & 0xff);
-	default:
-	  return 0;
-	}
-      /* NOTREACHED */
-
-    case _SC_LEVEL2_CACHE_LINESIZE:
-      return (ecx & 0xf000) == 0 ? 0 : ecx & 0xff;
-
-    case _SC_LEVEL3_CACHE_SIZE:
-      return (edx & 0xf000) == 0 ? 0 : (edx & 0x3ffc0000) << 1;
-
-    case _SC_LEVEL3_CACHE_ASSOC:
-      switch ((edx >> 12) & 0xf)
-	{
-	case 0:
-	case 1:
-	case 2:
-	case 4:
-	  return (edx >> 12) & 0xf;
-	case 6:
-	  return 8;
-	case 8:
-	  return 16;
-	case 10:
-	  return 32;
-	case 11:
-	  return 48;
-	case 12:
-	  return 64;
-	case 13:
-	  return 96;
-	case 14:
-	  return 128;
-	case 15:
-	  return ((edx & 0x3ffc0000) << 1) / (edx & 0xff);
-	default:
-	  return 0;
-	}
-      /* NOTREACHED */
-
-    case _SC_LEVEL3_CACHE_LINESIZE:
-      return (edx & 0xf000) == 0 ? 0 : edx & 0xff;
-
-    default:
-      assert (! "cannot happen");
+       case _SC_LEVEL1_ICACHE_ASSOC:
+       case _SC_LEVEL1_DCACHE_ASSOC:
+       case _SC_LEVEL2_CACHE_ASSOC:
+       case _SC_LEVEL3_CACHE_ASSOC:
+         return ecx?((ebx >> 22) & 0x3ff) + 1 : 0;
+       case _SC_LEVEL1_ICACHE_LINESIZE:
+       case _SC_LEVEL1_DCACHE_LINESIZE:
+       case _SC_LEVEL2_CACHE_LINESIZE:
+       case _SC_LEVEL3_CACHE_LINESIZE:
+         return ecx?(ebx & 0xfff) + 1 : 0;
+       case _SC_LEVEL1_ICACHE_SIZE:
+       case _SC_LEVEL1_DCACHE_SIZE:
+       case _SC_LEVEL2_CACHE_SIZE:
+       case _SC_LEVEL3_CACHE_SIZE:
+         return ecx?(((ebx >> 22) & 0x3ff) + 1)*((ebx & 0xfff) + 1)\
+                                                    *(ecx + 1):0;
+       default:
+         assert (! "cannot happen");
     }
   return -1;
 }
@@ -710,36 +640,8 @@ intel_bug_no_cache_info:
       __cpuid (0x80000000, max_cpuid_ex, ebx, ecx, edx);
 
       if (shared <= 0)
-	/* No shared L3 cache.  All we have is the L2 cache.  */
-	shared = core;
-      else
-	{
-	  /* Figure out the number of logical threads that share L3.  */
-	  if (max_cpuid_ex >= 0x80000008)
-	    {
-	      /* Get width of APIC ID.  */
-	      __cpuid (0x80000008, max_cpuid_ex, ebx, ecx, edx);
-	      threads = 1 << ((ecx >> 12) & 0x0f);
-	    }
-
-	  if (threads == 0)
-	    {
-	      /* If APIC ID width is not available, use logical
-		 processor count.  */
-	      __cpuid (0x00000001, max_cpuid_ex, ebx, ecx, edx);
-
-	      if ((edx & (1 << 28)) != 0)
-		threads = (ebx >> 16) & 0xff;
-	    }
-
-	  /* Cap usage of highest cache level to the number of
-	     supported threads.  */
-	  if (threads > 0)
-	    shared /= threads;
-
-	  /* Account for exclusive L2 and L3 caches.  */
-	  shared += core;
-	}
+        /* No shared L3 cache.  All we have is the L2 cache.  */
+         shared = core;
 
 #ifndef DISABLE_PREFETCHW
       if (max_cpuid_ex >= 0x80000001)

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