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-rw-r--r--arch/arch-x86-common.h43
1 files changed, 43 insertions, 0 deletions
diff --git a/arch/arch-x86-common.h b/arch/arch-x86-common.h
new file mode 100644
index 00000000..1e623544
--- /dev/null
+++ b/arch/arch-x86-common.h
@@ -0,0 +1,43 @@
+#ifndef FIO_ARCH_X86_COMMON
+#define FIO_ARCH_X86_COMMON
+
+static inline void do_cpuid(unsigned int *eax, unsigned int *ebx,
+ unsigned int *ecx, unsigned int *edx)
+{
+ unsigned int id = *eax;
+
+ asm("movl %4, %%eax;"
+ "cpuid;"
+ "movl %%eax, %0;"
+ "movl %%ebx, %1;"
+ "movl %%ecx, %2;"
+ "movl %%edx, %3;"
+ : "=r" (*eax), "=r" (*ebx), "=r" (*ecx), "=r" (*edx)
+ : "r" (id)
+ : "eax", "ebx", "ecx", "edx");
+}
+
+#define ARCH_HAVE_INIT
+extern int tsc_reliable;
+static inline int arch_init(char *envp[])
+{
+ unsigned int eax, ebx, ecx, edx;
+
+ /*
+ * Check for TSC
+ */
+ eax = 1;
+ do_cpuid(&eax, &ebx, &ecx, &edx);
+ if (!(edx & (1U << 4)))
+ return 0;
+
+ /*
+ * Check for constant rate and synced (across cores) TSC
+ */
+ eax = 0x80000007;
+ do_cpuid(&eax, &ebx, &ecx, &edx);
+ tsc_reliable = edx & (1U << 8);
+ return 0;
+}
+
+#endif