cpu/intel/haswell/acpi.c: Correct `get_cores_per_package`

CPUID result does not change when HyperThreading is disabled on
HT-enabled CPUs, which breaks `generate_cpu_entries`. Use MSR 0x35
instead, which returns the currently-enabled core and thread count.
Also rename the function to `get_logical_cores_per_package, which is
more accurate. Based on commit 920d2b77f2 (cpu/intel/206ax/acpi.c: Fix
get_cores_per_package). The MSR definition is the same for Sandy Bridge
and Haswell.

Change-Id: I5e1789d3037780b4285c9e367ff0e2b0d4365b39
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/49099
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/cpu/intel/haswell/acpi.c b/src/cpu/intel/haswell/acpi.c
index 0f11e5f..401e82b 100644
--- a/src/cpu/intel/haswell/acpi.c
+++ b/src/cpu/intel/haswell/acpi.c
@@ -32,20 +32,10 @@
 	C_STATE_C6_LONG_LAT,
 };
 
-static int get_cores_per_package(void)
+static int get_logical_cores_per_package(void)
 {
-	struct cpuinfo_x86 c;
-	struct cpuid_result result;
-	int cores = 1;
-
-	get_fms(&c, cpuid_eax(1));
-	if (c.x86 != 6)
-		return 1;
-
-	result = cpuid_ext(0xb, 1);
-	cores = result.ebx & 0xff;
-
-	return cores;
+	msr_t msr = rdmsr(MSR_CORE_THREAD_COUNT);
+	return msr.lo & 0xffff;
 }
 
 static acpi_tstate_t tss_table_fine[] = {
@@ -279,7 +269,7 @@
 {
 	int coreID, cpuID, pcontrol_blk = get_pmbase(), plen = 6;
 	int totalcores = dev_count_cpu();
-	int cores_per_package = get_cores_per_package();
+	int cores_per_package = get_logical_cores_per_package();
 	int numcpus = totalcores/cores_per_package;
 
 	printk(BIOS_DEBUG, "Found %d CPU(s) with %d core(s) each.\n",