*x86: Support x2apic mode

Implement x2apic mode as existing code only supports apic mode.
Use info from LAPIC_BASE_MSR (LAPIC_BASE_MSR_X2APIC_MODE) to check
if apic mode or x2apic mode and implement x2apic mode according to
x2apic specfication.

Reference:
https://software.intel.com/content/www/us/en/develop/download/intel-64-architecture-x2apic-specification.html

BUG=None
BRANCH=None
TEST=boot to OS and check apic mode
cat /proc/cpuinfo | grep "apicid"
ex) can see apicid bigger than 255
apicid          : 256
apicid          : 260

Signed-off-by: Wonkyu Kim <wonkyu.kim@intel.com>
Change-Id: I0bb729b0521fb9dc38b7981014755daeaf9ca817
Reviewed-on: https://review.coreboot.org/c/coreboot/+/51723
Reviewed-by: Ravishankar Sarawadi <ravishankar.sarawadi@intel.com>
Reviewed-by: Jamie Ryu <jamie.m.ryu@intel.com>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

3 files changed, 52 insertions, 9 deletions

diff --git a/src/cpu/x86/lapic/lapic.c b/src/cpu/x86/lapic/lapic.c
index 988d664c94..a5b4cd5047 100644
--- a/src/cpu/x86/lapic/lapic.c
+++ b/src/cpu/x86/lapic/lapic.c
@@ -47,6 +47,6 @@ void lapic_virtual_wire_mode_init(void)
 			LAPIC_DELIVERY_MODE_NMI)
 		);
 
-	printk(BIOS_DEBUG, " apic_id: 0x%02x ", lapicid());
+	printk(BIOS_DEBUG, " apic_id: 0x%x ", lapicid());
 	printk(BIOS_INFO, "done.\n");
 }
diff --git a/src/cpu/x86/mp_init.c b/src/cpu/x86/mp_init.c
index 94a8fd8d8b..76f2650330 100644
--- a/src/cpu/x86/mp_init.c
+++ b/src/cpu/x86/mp_init.c
@@ -435,6 +435,28 @@ static int start_aps(struct bus *cpu_bus, int ap_count, atomic_t *num_aps)
 
 	printk(BIOS_DEBUG, "Attempting to start %d APs\n", ap_count);
 
+	if (is_x2apic_mode()) {
+		x2apic_send_ipi(LAPIC_DM_INIT | LAPIC_INT_LEVELTRIG |
+			LAPIC_INT_ASSERT | LAPIC_DEST_ALLBUT, 0);
+		mdelay(10);
+		x2apic_send_ipi(LAPIC_DM_STARTUP | LAPIC_INT_LEVELTRIG |
+			LAPIC_DEST_ALLBUT | sipi_vector, 0);
+
+		/* Wait for CPUs to check in up to 200 us. */
+		wait_for_aps(num_aps, ap_count, 200 /* us */, 15 /* us */);
+
+		x2apic_send_ipi(LAPIC_DM_STARTUP | LAPIC_INT_LEVELTRIG |
+			LAPIC_DEST_ALLBUT | sipi_vector, 0);
+
+		/* Wait for CPUs to check in. */
+		if (wait_for_aps(num_aps, ap_count, 100000 /* 100 ms */, 50 /* us */)) {
+			printk(BIOS_ERR, "Not all APs checked in: %d/%d.\n",
+			       atomic_read(num_aps), ap_count);
+			return -1;
+		}
+		return 0;
+	}
+
 	if ((lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY)) {
 		printk(BIOS_DEBUG, "Waiting for ICR not to be busy...");
 		if (apic_wait_timeout(1000 /* 1 ms */, 50)) {
@@ -653,6 +675,11 @@ static void mp_initialize_cpu(void)
 
 void smm_initiate_relocation_parallel(void)
 {
+	if (is_x2apic_mode()) {
+		x2apic_send_ipi(LAPIC_DM_SMI | LAPIC_INT_LEVELTRIG, lapicid());
+		return;
+	}
+
 	if ((lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY)) {
 		printk(BIOS_DEBUG, "Waiting for ICR not to be busy...");
 		if (apic_wait_timeout(1000 /* 1 ms */, 50)) {
diff --git a/src/cpu/x86/smm/smm_stub.S b/src/cpu/x86/smm/smm_stub.S
index 7c09e04108..f479d62536 100644
--- a/src/cpu/x86/smm/smm_stub.S
+++ b/src/cpu/x86/smm/smm_stub.S
@@ -11,6 +11,7 @@
 
 #include <cpu/x86/cr.h>
 #include <cpu/x86/msr.h>
+#include <cpu/x86/lapic_def.h>
 
 .code32
 .section ".module_parameters", "aw", @progbits
@@ -29,7 +30,7 @@ fxsave_area_size:
  * APIC id is found at the given index, the contiguous CPU number is index
  * into the table. */
 apic_to_cpu_num:
-.fill CONFIG_MAX_CPUS,1,0xff
+.fill CONFIG_MAX_CPUS,2,0xffff
 /* allows the STM to bring up SMM in 32-bit mode */
 start32_offset:
 .long smm_trampoline32 - _start
@@ -97,16 +98,31 @@ smm_trampoline32:
 
 	/* The CPU number is calculated by reading the initial APIC id. Since
 	 * the OS can maniuplate the APIC id use the non-changing cpuid result
-	 * for APIC id (ebx[31:24]). A table is used to handle a discontiguous
+	 * for APIC id (ax). A table is used to handle a discontiguous
 	 * APIC id space.  */
-	mov	$1, %eax
-	cpuid
-	bswap	%ebx	/* Default APIC id in bl. */
-	mov	$(apic_to_cpu_num), %eax
-	xor	%ecx, %ecx
+apic_id:
+        mov $LAPIC_BASE_MSR, %ecx
+        rdmsr
+        andl $LAPIC_BASE_MSR_X2APIC_MODE, %eax
+        jz xapic
+
+x2apic:
+        mov $X2APIC_LAPIC_ID, %ecx
+        rdmsr
+        jmp apicid_end
+
+xapic:
+        movl    $(LOCAL_APIC_ADDR | LAPIC_ID), %esi
+        movl    (%esi), %eax
+        shr     $24, %eax
+
+apicid_end:
+
+        mov     $(apic_to_cpu_num), %ebx
+        xor     %ecx, %ecx
 
 1:
-	cmp	(%eax, %ecx, 1), %bl
+	cmp	(%ebx, %ecx, 2), %ax
 	je	1f
 	inc	%ecx
 	cmp	$CONFIG_MAX_CPUS, %ecx