New patch to review for coreboot: 6a1c93f sandybridge: Correct reporting of cores and threads

[Stefan Reinauer]

Stefan Reinauer ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/1786

-gerrit

commit 6a1c93f31c77dd8b5d8c6a10829f84ad1230c396
Author: Stefan Reinauer 
Date:   Mon Oct 15 13:45:11 2012 -0700

sandybridge: Correct reporting of cores and threads

The reporting of cores and threads in the system was a bit
    ambiguous. This patch makes it clearer.

Change-Id: Ia05838a53f696fbaf78a1762fc6f4bf348d4ff0e
    Signed-off-by: Stefan Reinauer 
---
 src/cpu/intel/model_206ax/model_206ax_init.c | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/src/cpu/intel/model_206ax/model_206ax_init.c b/src/cpu/intel/model_206ax/model_206ax_init.c
index f7a5c09..6dfc12f 100644
--- a/src/cpu/intel/model_206ax/model_206ax_init.c
+++ b/src/cpu/intel/model_206ax/model_206ax_init.c
@@ -436,22 +436,25 @@ static unsigned ehci_debug_addr;
 static void intel_cores_init(device_t cpu)
 {
    struct cpuid_result result;
-	unsigned cores, threads, i;
+	unsigned threads_per_package, threads_per_core, i;

-	result = cpuid_ext(0xb, 0); /* Threads per core */
-	threads = result.ebx & 0xff;
+	/* Logical processors (threads) per core */
+	result = cpuid_ext(0xb, 0);
+	threads_per_core = result.ebx & 0xffff;

-	result = cpuid_ext(0xb, 1); /* Cores per package */
-	cores = result.ebx & 0xff;
+	/* Logical processors (threads) per package */
+	result = cpuid_ext(0xb, 1);
+	threads_per_package = result.ebx & 0xffff;

/* Only initialize extra cores from BSP */
    if (cpu->path.apic.apic_id)
    	return;

-	printk(BIOS_DEBUG, "CPU: %u has %u cores %u threads\n",
-	       cpu->path.apic.apic_id, cores, threads);
+	printk(BIOS_DEBUG, "CPU: %u has %u cores, %u threads per core\n",
+	       cpu->path.apic.apic_id, threads_per_package/threads_per_core,
+	       threads_per_core);

-	for (i = 1; i < cores; ++i) {
+	for (i = 1; i < threads_per_package; ++i) {
    	struct device_path cpu_path;
    	device_t new;

@@ -461,7 +464,7 @@ static void intel_cores_init(device_t cpu)
    		cpu->path.apic.apic_id + i;

/* Update APIC ID if no hyperthreading */
-		if (threads == 1)
+		if (threads_per_core == 1)
    		cpu_path.apic.apic_id <<= 1;

/* Allocate the new cpu device structure */