1 files changed, 89 insertions, 0 deletions
diff --git a/libparc/parc/developer/parc_TimingIntel.c b/libparc/parc/developer/parc_TimingIntel.c
new file mode 100755
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+++ b/libparc/parc/developer/parc_TimingIntel.c
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+/*
+ * Copyright (c) 2017 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Executes either the RDTSC or RDTSCP instruction, depending on platform availability
+ *
+ */
+
+#include <config.h>
+#include <stdio.h>
+
+#define PARCTIMING_ENABLE
+#include <parc/developer/parc_Timing.h>
+
+#ifdef PARCTIMING_INTEL
+static bool _useRdtscp = false;
+static bool _needCheckRdtscp = true;
+
+#include <cpuid.h>
+
+static void
+_checkRdtscp(void)
+{
+    // See the CPUID instruction for description of the codes.
+
+    // determine the maximum extended information set
+    unsigned maxextended = __get_cpuid_max(0x80000000, NULL);
+
+    // RDTSCP status flag is in the 0x800000001 feature set
+    const unsigned feature = 0x80000001;
+    const unsigned rdtscp_feature = 1 << 27;
+
+    if (maxextended >= feature) {
+        unsigned eax, ebx, ecx, edx;
+
+        int success = __get_cpuid(feature, &eax, &ebx, &ecx, &edx);
+        if (success) {
+            _useRdtscp = (edx & rdtscp_feature ? true : false);
+        }
+    }
+}
+#endif // PARCTIMING_INTEL
+
+void
+parcTiminIntel_RuntimeInit(void)
+{
+#ifdef PARCTIMING_INTEL
+    if (_needCheckRdtscp) {
+        _needCheckRdtscp = false;
+        _checkRdtscp();
+    }
+#endif // PARCTIMING_INTEL
+}
+
+void
+parcTimingIntel_rdtsc(unsigned *hi, unsigned *lo)
+{
+    /*
+     * Older CPUs do not support RDTSCP, which is the better instruction to use.
+     * If we did not detect this opcode in autoconf, use the older RDTSC
+     */
+
+#ifdef PARCTIMING_INTEL
+    if (_useRdtscp) {
+        __asm volatile ("RDTSCP\n\t"
+                        "mov %%edx,%0\n\t"
+                        "mov %%eax,%1\n\t"
+                        "CPUID\n\t" : "=r" (*hi), "=r" (*lo):: "%rax", "%rbx", "%rcx", "%rdx");
+    } else {
+        __asm volatile ("RDTSC\n\t"
+                        "mov %%edx,%0\n\t"
+                        "mov %%eax,%1\n\t"
+                        "CPUID\n\t" : "=r" (*hi), "=r" (*lo):: "%rax", "%rbx", "%rcx", "%rdx");
+    }
+#endif  // PARCTIMING_INTEL
+}
+