summaryrefslogtreecommitdiffstats
path: root/src/arch/x86/cpu_common.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/arch/x86/cpu_common.c')
-rw-r--r--src/arch/x86/cpu_common.c65
1 files changed, 65 insertions, 0 deletions
diff --git a/src/arch/x86/cpu_common.c b/src/arch/x86/cpu_common.c
new file mode 100644
index 0000000..af0ab2a
--- /dev/null
+++ b/src/arch/x86/cpu_common.c
@@ -0,0 +1,65 @@
+#include <console/console.h>
+#include <cpu/cpu.h>
+#include <arch/io.h>
+#include <string.h>
+#include <cpu/x86/mtrr.h>
+#include <cpu/x86/msr.h>
+#include <cpu/x86/lapic.h>
+#include <arch/cpu.h>
+#include <device/path.h>
+#include <device/device.h>
+#include <smp/spinlock.h>
+
+#ifndef __x86_64__
+/* Standard macro to see if a specific flag is changeable */
+static inline int flag_is_changeable_p(uint32_t flag)
+{
+ uint32_t f1, f2;
+
+ asm(
+ "pushfl\n\t"
+ "pushfl\n\t"
+ "popl %0\n\t"
+ "movl %0,%1\n\t"
+ "xorl %2,%0\n\t"
+ "pushl %0\n\t"
+ "popfl\n\t"
+ "pushfl\n\t"
+ "popl %0\n\t"
+ "popfl\n\t"
+ : "=&r" (f1), "=&r" (f2)
+ : "ir" (flag));
+ return ((f1^f2) & flag) != 0;
+}
+
+/* Probe for the CPUID instruction */
+int cpu_have_cpuid(void)
+{
+ return flag_is_changeable_p(X86_EFLAGS_ID);
+}
+
+#else
+
+int cpu_have_cpuid(void)
+{
+ return 1;
+}
+#endif
+
+int cpu_cpuid_extended_level(void)
+{
+ return cpuid_eax(0x80000000);
+}
+
+int cpu_phys_address_size(void)
+{
+ if (!(cpu_have_cpuid()))
+ return 32;
+
+ if (cpu_cpuid_extended_level() >= 0x80000008)
+ return cpuid_eax(0x80000008) & 0xff;
+
+ if (cpuid_edx(1) & (CPUID_FEATURE_PAE | CPUID_FEATURE_PSE36))
+ return 36;
+ return 32;
+}
OpenPOWER on IntegriCloud