1 files changed, 70 insertions, 0 deletions
diff --git a/include/grub/i386/tsc.h b/include/grub/i386/tsc.h
new file mode 100644
index 0000000..947e62f
--- /dev/null
+++ b/include/grub/i386/tsc.h
@@ -0,0 +1,70 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2008,2009  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef KERNEL_CPU_TSC_HEADER
+#define KERNEL_CPU_TSC_HEADER   1
+
+#include <grub/types.h>
+#include <grub/i386/cpuid.h>
+
+void grub_tsc_init (void);
+/* In ms per 2^32 ticks.  */
+extern grub_uint32_t EXPORT_VAR(grub_tsc_rate);
+int
+grub_tsc_calibrate_from_xen (void);
+int
+grub_tsc_calibrate_from_efi (void);
+int
+grub_tsc_calibrate_from_pmtimer (void);
+int
+grub_tsc_calibrate_from_pit (void);
+
+/* Read the TSC value, which increments with each CPU clock cycle. */
+static __inline grub_uint64_t
+grub_get_tsc (void)
+{
+  grub_uint32_t lo, hi;
+  grub_uint32_t a,b,c,d;
+
+  /* The CPUID instruction is a 'serializing' instruction, and
+     avoids out-of-order execution of the RDTSC instruction. */
+  grub_cpuid (0,a,b,c,d);
+  /* Read TSC value.  We cannot use "=A", since this would use
+     %rax on x86_64. */
+  asm volatile ("rdtsc":"=a" (lo), "=d" (hi));
+
+  return (((grub_uint64_t) hi) << 32) | lo;
+}
+
+static __inline int
+grub_cpu_is_tsc_supported (void)
+{
+#if !defined(GRUB_MACHINE_XEN) && !defined(GRUB_MACHINE_XEN_PVH)
+  grub_uint32_t a,b,c,d;
+  if (! grub_cpu_is_cpuid_supported ())
+    return 0;
+
+  grub_cpuid(1,a,b,c,d);
+
+  return (d & (1 << 4)) != 0;
+#else
+  return 1;
+#endif
+}
+
+#endif /* ! KERNEL_CPU_TSC_HEADER */