[PATCH] x86: don't use cpuid.2 to determine cache info if cpuid.4 is …

…supported

Don't use cpuid.2 to determine cache info if cpuid.4 is supported.  The
exception is P4 trace cache.  We always use cpuid.2 to get trace cache
under P4.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/i386/kernel/cpu/intel_cacheinfo.c

@@ -225,11 +225,19 @@ unsigned int __cpuinit init_intel_cacheinfo(struct cpuinfo_x86 *c)
 			}
 		}
 	}
-	if (c->cpuid_level > 1) {
+	/*
+	 * Don't use cpuid2 if cpuid4 is supported. For P4, we use cpuid2 for
+	 * trace cache
+	 */
+	if ((num_cache_leaves == 0 || c->x86 == 15) && c->cpuid_level > 1) {
 		/* supports eax=2  call */
 		int i, j, n;
 		int regs[4];
 		unsigned char *dp = (unsigned char *)regs;
+		int only_trace = 0;
+
+		if (num_cache_leaves != 0 && c->x86 == 15)
+			only_trace = 1;
 
 		/* Number of times to iterate */
 		n = cpuid_eax(2) & 0xFF;
@@ -251,6 +259,8 @@ unsigned int __cpuinit init_intel_cacheinfo(struct cpuinfo_x86 *c)
 				while (cache_table[k].descriptor != 0)
 				{
 					if (cache_table[k].descriptor == des) {
+						if (only_trace && cache_table[k].cache_type != LVL_TRACE)
+							break;
 						switch (cache_table[k].cache_type) {
 						case LVL_1_INST:
 							l1i += cache_table[k].size;
@@ -276,43 +286,46 @@ unsigned int __cpuinit init_intel_cacheinfo(struct cpuinfo_x86 *c)
 				}
 			}
 		}
+	}
 
-		if (new_l1d)
-			l1d = new_l1d;
+	if (new_l1d)
+		l1d = new_l1d;
 
-		if (new_l1i)
-			l1i = new_l1i;
+	if (new_l1i)
+		l1i = new_l1i;
 
-		if (new_l2) {
-			l2 = new_l2;
+	if (new_l2) {
+		l2 = new_l2;
 #ifdef CONFIG_SMP
-			cpu_llc_id[cpu] = l2_id;
+		cpu_llc_id[cpu] = l2_id;
 #endif
-		}
+	}
 
-		if (new_l3) {
-			l3 = new_l3;
+	if (new_l3) {
+		l3 = new_l3;
 #ifdef CONFIG_SMP
-			cpu_llc_id[cpu] = l3_id;
+		cpu_llc_id[cpu] = l3_id;
 #endif
-		}
-
-		if ( trace )
-			printk (KERN_INFO "CPU: Trace cache: %dK uops", trace);
-		else if ( l1i )
-			printk (KERN_INFO "CPU: L1 I cache: %dK", l1i);
-		if ( l1d )
-			printk(", L1 D cache: %dK\n", l1d);
-		else
-			printk("\n");
-		if ( l2 )
-			printk(KERN_INFO "CPU: L2 cache: %dK\n", l2);
-		if ( l3 )
-			printk(KERN_INFO "CPU: L3 cache: %dK\n", l3);
-
-		c->x86_cache_size = l3 ? l3 : (l2 ? l2 : (l1i+l1d));
 	}
 
+	if (trace)
+		printk (KERN_INFO "CPU: Trace cache: %dK uops", trace);
+	else if ( l1i )
+		printk (KERN_INFO "CPU: L1 I cache: %dK", l1i);
+
+	if (l1d)
+		printk(", L1 D cache: %dK\n", l1d);
+	else
+		printk("\n");
+
+	if (l2)
+		printk(KERN_INFO "CPU: L2 cache: %dK\n", l2);
+
+	if (l3)
+		printk(KERN_INFO "CPU: L3 cache: %dK\n", l3);
+
+	c->x86_cache_size = l3 ? l3 : (l2 ? l2 : (l1i+l1d));
+
 	return l2;
 }