From 6346f5459488496938a533aa26f8ead83490940f Mon Sep 17 00:00:00 2001
From: stefan <stefan@315a16e6-25f9-4109-90ae-ca3045a26c18>
Date: Wed, 24 Nov 2010 19:05:04 +0000
Subject: [PATCH] - redesign of the function cpuid to avoid unintentional
 overriding of registers

git-svn-id: http://svn.lfbs.rwth-aachen.de/svn/scc/trunk/MetalSVM@268 315a16e6-25f9-4109-90ae-ca3045a26c18
---
 arch/x86/include/asm/processor.h | 14 ++++++++++----
 arch/x86/kernel/apic.c           |  4 ++--
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index e653e083..c4256220 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -66,10 +66,16 @@ inline static void rmb(void) { asm volatile("lfence" ::: "memory"); }
 inline static void wmb(void) { asm volatile("sfence" ::: "memory"); }
 #endif
 
-inline static uint32_t cpuid(uint32_t code, uint32_t* feature) {
-	uint32_t ret;
-	asm volatile("cpuid" : "=a"(ret), "=d"(*feature) : "0"(code));
-	return ret;
+inline static void cpuid(uint32_t code, uint32_t* a, uint32_t* b, uint32_t* c, uint32_t* d) {
+	asm volatile ("cpuid" : "=a"(*a), "=b"(*b), "=c"(*c), "=d"(*d) : "0"(code));
+}
+
+inline static void flush_pipeline(void) {
+	uint32_t low = 0;
+	uint32_t high = 0;
+	uint32_t code = 0;
+
+	asm volatile ("cpuid" : "=a"(low), "=d"(high) : "0"(code) : "%ebx", "%ecx");
 }
 
 inline static uint64_t rdmsr(uint32_t msr) {
diff --git a/arch/x86/kernel/apic.c b/arch/x86/kernel/apic.c
index 273545d1..8501ffb1 100644
--- a/arch/x86/kernel/apic.c
+++ b/arch/x86/kernel/apic.c
@@ -110,7 +110,7 @@ int apic_calibration(void)
 static int apic_probe(void)
 {
 	size_t addr;
-	uint32_t i, count;
+	uint32_t i, count, dummy;
 
 	// searching MP signature in the reserved memory areas
 #ifdef CONFIG_MULTIBOOT
@@ -181,7 +181,7 @@ found_mp:
 	kprintf("Maximum LVT Entry: 0x%x\n", (i >> 16) & 0xFF);
 	kprintf("APIC Version: 0x%x\n", i & 0xFF);
 
-	cpuid(0x1, &i);
+	cpuid(0x1, &i, &dummy, &dummy, &dummy);
 	if (!(i & (1 << 5))) {
 		kputs("Unable to use Machine-Specific Registers (MSR)\n");
 		goto out;