[coreboot] New patch to review for coreboot: 904a808 Avoid using CPUID in SMBIOS tables. Check for CPUID otherwise claim 486 class cpu.

[Rudolf Marek]

Rudolf Marek ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/683

-gerrit

commit 904a8089cf7017480da09c0c1b1754af404e08e3
Author: Rudolf Marek 
Date:   Sat Feb 25 23:51:12 2012 +0100

Avoid using CPUID in SMBIOS tables. Check for CPUID otherwise claim 486 class cpu.

Change-Id: Ic7c4452a1b55bae0cefee118003540ec39ef9fd4
    Signed-off-by: Rudolf Marek 
---
 src/arch/x86/boot/smbios.c      |   49 ++++++++++++++++++++++++--------------
 src/arch/x86/include/arch/cpu.h |   29 +++++++++++++++++++++++
 src/arch/x86/lib/cpu.c          |   29 -----------------------
 3 files changed, 60 insertions(+), 47 deletions(-)

diff --git a/src/arch/x86/boot/smbios.c b/src/arch/x86/boot/smbios.c
index e5156d9..7e2729c 100644
--- a/src/arch/x86/boot/smbios.c
+++ b/src/arch/x86/boot/smbios.c
@@ -76,34 +76,41 @@ int smbios_string_table_len(char *start)

static int smbios_cpu_vendor(char *start)
 {
-	char tmp[13];
+	char tmp[13] = "Unknown";
    u32 *_tmp = (u32 *)tmp;
-	struct cpuid_result res = cpuid(0);
+	struct cpuid_result res;

-	_tmp[0] = res.ebx;
-	_tmp[1] = res.edx;
-	_tmp[2] = res.ecx;
-	tmp[12] = '\0';
-	return smbios_add_string(start, tmp);
+	if (have_cpuid_p()) {
+		res = cpuid(0);
+		_tmp[0] = res.ebx;
+		_tmp[1] = res.edx;
+		_tmp[2] = res.ecx;
+		tmp[12] = '\0';
+	}

+	return smbios_add_string(start, tmp);
 }

static int smbios_processor_name(char *start)
 {
-	char tmp[49];
+	char tmp[49] = "Unknown Processor Name";
    u32  *_tmp = (u32 *)tmp;
    struct cpuid_result res;
    int i;

-	for (i = 0; i < 3; i++) {
-		res = cpuid(0x80000002 + i);
-		_tmp[i * 4 + 0] = res.eax;
-		_tmp[i * 4 + 1] = res.ebx;
-		_tmp[i * 4 + 2] = res.ecx;
-		_tmp[i * 4 + 3] = res.edx;
+	if (have_cpuid_p()) {
+		res = cpuid(0x80000000);
+		if (res.eax > 0x80000004) {
+			for (i = 0; i < 3; i++) {
+				res = cpuid(0x80000002 + i);
+				_tmp[i * 4 + 0] = res.eax;
+				_tmp[i * 4 + 1] = res.ebx;
+				_tmp[i * 4 + 2] = res.ecx;
+				_tmp[i * 4 + 3] = res.edx;
+			}
+			tmp[48] = 0;
+		}
    }
-
-	tmp[48] = 0;
    return smbios_add_string(start, tmp);
 }

@@ -184,7 +191,13 @@ static int smbios_write_type4(unsigned long *current, int handle)
    struct smbios_type4 *t = (struct smbios_type4 *)*current;
    int len = sizeof(struct smbios_type4);

-	res = cpuid(1);
+	/* Provide sane defaults even for CPU without CPUID */
+	res.eax = res.edx = 0;
+	res.ebx = 0x10000;
+
+	if (have_cpuid_p()) {
+		res = cpuid(1);
+	}

memset(t, 0, sizeof(struct smbios_type4));
    t->type = SMBIOS_PROCESSOR_INFORMATION;
@@ -194,7 +207,7 @@ static int smbios_write_type4(unsigned long *current, int handle)
    t->processor_id[1] = res.edx;
    t->processor_manufacturer = smbios_cpu_vendor(t->eos);
    t->processor_version = smbios_processor_name(t->eos);
-	t->processor_family = 0x0c;
+	t->processor_family = (res.eax > 0) ? 0x0c : 0x6;
    t->processor_type = 3; /* System Processor */
    t->processor_upgrade = 0x06;
    t->core_count = (res.ebx >> 16) & 0xff;
diff --git a/src/arch/x86/include/arch/cpu.h b/src/arch/x86/include/arch/cpu.h
index 85357d7..4f395ce 100644
--- a/src/arch/x86/include/arch/cpu.h
+++ b/src/arch/x86/include/arch/cpu.h
@@ -29,6 +29,35 @@ struct cpuid_result {
    uint32_t edx;
 };

+/* 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 */
+static int have_cpuid_p(void)
+{
+	return flag_is_changeable_p(X86_EFLAGS_ID);
+}
+
+
 /*
  * Generic CPUID function
  */
diff --git a/src/arch/x86/lib/cpu.c b/src/arch/x86/lib/cpu.c
index ada57e2..60296be 100644
--- a/src/arch/x86/lib/cpu.c
+++ b/src/arch/x86/lib/cpu.c
@@ -9,35 +9,6 @@
 #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 */
-static int have_cpuid_p(void)
-{
-	return flag_is_changeable_p(X86_EFLAGS_ID);
-}
-
 /*
  * Cyrix CPUs without cpuid or with cpuid not yet enabled can be detected
  * by the fact that they preserve the flags across the division of 5/2.