Add qemu 2.4.0

[kvmfornfv.git] / qemu / roms / ipxe / src / arch / i386 / include / ipxe / rdtsc_timer.h

diff --git a/qemu/roms/ipxe/src/arch/i386/include/ipxe/rdtsc_timer.h b/qemu/roms/ipxe/src/arch/i386/include/ipxe/rdtsc_timer.h
new file mode 100644 (file)
index 0000000..472e140
--- /dev/null
+++ b/qemu/roms/ipxe/src/arch/i386/include/ipxe/rdtsc_timer.h
@@ -0,0 +1,39 @@
+#ifndef _IPXE_RDTSC_TIMER_H
+#define _IPXE_RDTSC_TIMER_H
+
+/** @file
+ *
+ * RDTSC timer
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#ifdef TIMER_RDTSC
+#define TIMER_PREFIX_rdtsc
+#else
+#define TIMER_PREFIX_rdtsc __rdtsc_
+#endif
+
+/**
+ * RDTSC values can easily overflow an unsigned long.  We discard the
+ * low-order bits in order to obtain sensibly-scaled values.
+ */
+#define TSC_SHIFT 8
+
+/**
+ * Get current system time in ticks
+ *
+ * @ret ticks          Current time, in ticks
+ */
+static inline __always_inline unsigned long
+TIMER_INLINE ( rdtsc, currticks ) ( void ) {
+       unsigned long ticks;
+
+       __asm__ __volatile__ ( "rdtsc\n\t"
+                              "shrdl %1, %%edx, %%eax\n\t"
+                              : "=a" ( ticks ) : "i" ( TSC_SHIFT ) : "edx" );
+       return ticks;
+}
+
+#endif /* _IPXE_RDTSC_TIMER_H */