[coreboot] Patch set updated for coreboot: be8f6ab sandybridge: Correct reporting of cores and threads

Stefan Reinauer (stefan.reinauer@coreboot.org) gerrit at coreboot.org
Sun Nov 11 20:20:44 CET 2012


Stefan Reinauer (stefan.reinauer at coreboot.org) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/1786

-gerrit

commit be8f6ab972590c4dcc7ccee6622bda6019234334
Author: Stefan Reinauer <reinauer at chromium.org>
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 <reinauer at google.com>
---
 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 9676ad1..9654af1 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 */




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