src/cpu/aarch64/vm/vm_version_aarch64.cpp

rev 8079 : 8079203: AARCH64: Need to cater for different partner implementations
Summary: Parse /proc/cpuinfo to derive implementation specific info
Reviewed-by: aph

@@ -57,10 +57,12 @@
 #define HWCAP_CRC32 (1<<7)
 #endif
 
 int VM_Version::_cpu;
 int VM_Version::_model;
+int VM_Version::_variant;
+int VM_Version::_revision;
 int VM_Version::_stepping;
 int VM_Version::_cpuFeatures;
 const char*           VM_Version::_features_str = "";
 
 static BufferBlob* stub_blob;

@@ -127,10 +129,34 @@
   if (auxv & HWCAP_AES)   strcat(buf, ", aes");
   if (auxv & HWCAP_SHA1)  strcat(buf, ", sha1");
   if (auxv & HWCAP_SHA2)  strcat(buf, ", sha256");
 
   _features_str = strdup(buf);
+  _cpuFeatures = auxv;
+
+  if (FILE *f = fopen("/proc/cpuinfo", "r")) {
+    char buf[128], *p;
+    while (fgets(buf, sizeof (buf), f) != NULL) {
+      if (p = strchr(buf, ':')) {
+        long v = strtol(p+1, NULL, 0);
+        if (strncmp(buf, "CPU implementer", sizeof "CPU implementer" - 1) == 0) {
+          _cpu = v;
+        } else if (strncmp(buf, "CPU variant", sizeof "CPU variant" - 1) == 0) {
+          _variant = v;
+        } else if (strncmp(buf, "CPU part", sizeof "CPU part" - 1) == 0) {
+          _model = v;
+        } else if (strncmp(buf, "CPU revision", sizeof "CPU revision" - 1) == 0) {
+          _revision = v;
+        }
+      }
+    }
+    fclose(f);
+  }
+
+  // Enable vendor specific features
+  if (_cpu == CPU_CAVIUM) _cpuFeatures |= CPU_DMB_ATOMICS;
+  if (_cpu == CPU_ARM) _cpuFeatures |= CPU_A53MAC;
 
   if (FLAG_IS_DEFAULT(UseCRC32)) {
     UseCRC32 = (auxv & HWCAP_CRC32) != 0;
   }
   if (UseCRC32 && (auxv & HWCAP_CRC32) == 0) {

@@ -191,10 +217,14 @@
       warning("SHA512 instruction (for SHA-384 and SHA-512) is not available on this CPU.");
       FLAG_SET_DEFAULT(UseSHA512Intrinsics, false);
     }
   }
 
+  if (FLAG_IS_DEFAULT(UseBarriersForVolatile)) {
+    UseBarriersForVolatile = (_cpuFeatures & CPU_DMB_ATOMICS) != 0;
+  }
+
 #ifdef COMPILER2
   if (FLAG_IS_DEFAULT(OptoScheduling)) {
     OptoScheduling = true;
   }
 #endif