x86 cpu: Allow some cpuid functions during romstage

Allow calls to cpu_phys_address_size and its support functions during
romstage.  This enables the proper display of MTRRs during romstage
without duplicating this code.

BRANCH=none
BUG=None
TEST=Build and run on cyan

Change-Id: I6f6465c150a683ce91f1494ebb5d9ac60b75b795
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 6bfd517088b6a2e8a5958a837e6c8c471de19fd0
Original-Change-Id: I429f9beb69298836acdd71d17a7bcb717939dfc2
Original-Signed-off-by: Lee Leahy <Leroy.P.Leahy@intel.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/277392
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Original-Tested-by: Leroy P Leahy <leroy.p.leahy@intel.com>
Original-Commit-Queue: Leroy P Leahy <leroy.p.leahy@intel.com>
Reviewed-on: http://review.coreboot.org/10561
Tested-by: build bot (Jenkins)
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>

1 files changed, 56 insertions, 0 deletions

diff --git a/src/arch/x86/lib/cpu_common.c b/src/arch/x86/lib/cpu_common.c
new file mode 100644
index 0000000000..6c5561df98
--- /dev/null
+++ b/src/arch/x86/lib/cpu_common.c
@@ -0,0 +1,56 @@
+#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>
+
+/* 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);
+}
+
+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;
+}