Allow sysconf to return CPU cache information

        * include/sys/unistd.h (_SC_LEVEL*): Add cache-related variables as
        on Linux.

        * fhandler_proc.cc (format_proc_cpuinfo): Fetch cache information
        from new cache functions in sysconf.cc, get_cpu_cache_intel and
        get_cpu_cache_amd.
        * sysconf.cc (__nt_query_system): New local helper.
        (get_nproc_values): Utilize __nt_query_system on pre-Windows 7 systems.
        Use GetLogicalProcessorInformationEx otherwise to handle more than
        64 CPUs.  Only handle _SC_NPROCESSORS_CONF and _SC_NPROCESSORS_ONLN.
        (get_phys_pages): New helper to handle _SC_PHYS_PAGES.
        (cpuid2_cache_descriptor): New array to map Intel CPUID 2 descriptor
        values to cache type, cache size, associativity and linesize.
        (cpuid2_cache_desc_compar): Comparision function for bsearch over
        cpuid2_cache_descriptor.
        (get_cpu_cache_intel_cpuid2): New function to fetch cache info from
        Intel CPUID 2.
        (get_cpu_cache_intel_cpuid4): Ditto from Intel CPUID 4.
        (get_cpu_cache_intel): New function as CPU-specific entry point.
        (assoc): New array to map associativity values from AMD CPUID
        0x80000006.
        (get_cpu_cache_amd): New function to fetch cache info from AMD CPUIDs
        0x80000005 and 0x80000006.
        (get_cpu_cache): New function to fetch cache info.
        (sca): Call get_phys_pages if _SC_PHYS_PAGES is requested.  Call
        get_cpu_cache for new _SC_* cache requests.
        (SC_MAX): Set to _SC_LEVEL4_CACHE_LINESIZE.
        (get_phys_pages(void)): Call get_phys_pages(int).
        * include/cygwin/version.h (CYGWIN_VERSION_API_MINOR): Bump.

        * new-features.xml (ov-new2.3): Document sysconf cache addition.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

1 files changed, 32 insertions, 33 deletions

diff --git a/winsup/cygwin/fhandler_proc.cc b/winsup/cygwin/fhandler_proc.cc
index fca8265fe..d34bf3135 100644
--- a/winsup/cygwin/fhandler_proc.cc
+++ b/winsup/cygwin/fhandler_proc.cc
@@ -758,47 +758,46 @@ format_proc_cpuinfo (void *, char *&destbuf)
 	cache_alignment = clflush * 2;
       if (is_intel)
 	{
-	  uint32_t cache_level = 0;
-	  uint32_t info, layout, sets;
+	  extern long get_cpu_cache_intel (int sysc, uint32_t maxf);
+	  long cs;
 
-	  for (int idx = 0; ; ++idx)
+	  /* As on Linux, don't check for L3 cache. */
+	  cs = get_cpu_cache_intel (_SC_LEVEL2_CACHE_SIZE, maxf);
+	  if (cs == -1)
 	    {
-	      cpuid (&info, &layout, &sets, &unused, 0x00000004, idx);
-	      uint32_t cache_type = (info & 0x1f);
-	      if (cache_type == 0)
-		break;
-	      uint32_t cur_level = ((info >> 5) & 0x7);
-	      uint32_t ways = ((layout >> 22) & 0x3ff) + 1;
-	      uint32_t part = ((layout >> 12) & 0x3ff) + 1;
-	      uint32_t line = (layout & 0xfff) + 1;
-	      sets++;
-	      if (cur_level == cache_level)
-		cache_size += ways * part * line * sets;
-	      else if (cur_level > cache_level)
-		{
-		  cache_size = ways * part * line * sets;
-		  cache_level = cur_level;
-		}
+	      cs = get_cpu_cache_intel (_SC_LEVEL1_ICACHE_SIZE, maxf);
+	      if (cs != -1)
+		cache_size = cs;
+	      cs = get_cpu_cache_intel (_SC_LEVEL1_DCACHE_SIZE, maxf);
+	      if (cs != -1)
+		cache_size += cs;
 	    }
+	  else
+	    cache_size = cs;
 	  if (cache_size != -1)
 	    cache_size >>= 10;
 	}
-      /* L2 Cache and L2 TLB Identifiers. */
-      if (cache_size == -1 && maxe >= 0x80000006)
-	{
-	  uint32_t l2;
-	  cpuid (&unused, &unused, &l2, &unused, 0x80000006);
-
-	  cache_size = l2 >> 16;
-	}
-      /* L1 Cache and TLB Identifiers. */
-      if (cache_size == -1 && maxe >= 0x80000005)
+      else if (is_amd)
 	{
-	  uint32_t data_cache, inst_cache;
-	  cpuid (&unused, &unused, &data_cache, &inst_cache,
-		 0x80000005);
+	  extern long get_cpu_cache_amd (int sysc, uint32_t maxe);
+	  long cs;
 
-	  cache_size = (inst_cache >> 24) + (data_cache >> 24);
+	  cs = get_cpu_cache_amd (_SC_LEVEL3_CACHE_SIZE, maxe);
+	  if (cs == -1)
+	    cs = get_cpu_cache_amd (_SC_LEVEL2_CACHE_SIZE, maxe);
+	  if (cs == -1)
+	    {
+	      cs = get_cpu_cache_amd (_SC_LEVEL1_ICACHE_SIZE, maxe);
+	      if (cs != -1)
+		cache_size = cs;
+	      cs = get_cpu_cache_amd (_SC_LEVEL1_DCACHE_SIZE, maxe);
+	      if (cs != -1)
+		cache_size += cs;
+	    }
+	  else
+	    cache_size = cs;
+	  if (cache_size != -1)
+	    cache_size >>= 10;
 	}
       bufptr += __small_sprintf (bufptr, "cpu family\t: %d\n"
 					 "model\t\t: %d\n"