x86: Support CPU functions in long mode

At present it is not possible to find out the physical-address size in
long mode, so a predefined value is used.

Update the macros to support this properly, since it is important when
programming MTRRs.

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 24 insertions, 0 deletions

diff --git a/arch/x86/cpu/cpu.c b/arch/x86/cpu/cpu.c
index a8b21406ac0..c373b14df30 100644
--- a/arch/x86/cpu/cpu.c
+++ b/arch/x86/cpu/cpu.c
@@ -364,3 +364,27 @@ long locate_coreboot_table(void)
 
 	return addr;
 }
+
+static bool has_cpuid(void)
+{
+	return flag_is_changeable_p(X86_EFLAGS_ID);
+}
+
+static uint cpu_cpuid_extended_level(void)
+{
+	return cpuid_eax(0x80000000);
+}
+
+int cpu_phys_address_size(void)
+{
+	if (!has_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;
+}