[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;
@@ -276,6 +286,7 @@ unsigned int __cpuinit init_intel_cacheinfo(struct cpuinfo_x86 *c)
 				}
 			}
 		}
+	}
 
 	if (new_l1d)
 		l1d = new_l1d;
@@ -297,21 +308,23 @@ unsigned int __cpuinit init_intel_cacheinfo(struct cpuinfo_x86 *c)
 #endif
 	}
 
-		if ( trace )
+	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 )
+
+	if (l1d)
 		printk(", L1 D cache: %dK\n", l1d);
 	else
 		printk("\n");
-		if ( l2 )
+
+	if (l2)
 		printk(KERN_INFO "CPU: L2 cache: %dK\n", l2);
-		if ( l3 )
+
+	if (l3)
 		printk(KERN_INFO "CPU: L3 cache: %dK\n", l3);
 
 	c->x86_cache_size = l3 ? l3 : (l2 ? l2 : (l1i+l1d));
-	}
 
 	return l2;
 }