x86: parallel MP initialization

Provide a common entry point for bringing up the APs
in parallel. This work is based off of the Haswell one
which can be moved over to this in the future. The APs
are brought up and have the BSP's MTRRs duplicated in
their own MTRRs. Additionally, Microcode is loaded before
enabling caching. However, the current microcode loading
support assumes Intel's mechanism.

The infrastructure provides a notion of a flight plan
for the BSP and APs. This allows for flexibility in the
order of operations for a given architecture/chip without
providing any specific policy. Therefore, the chipset
caller can provide the order that is required.

BUG=chrome-os-partner:22862
BRANCH=None
TEST=Built and booted on rambi with baytrail specific patches.

Change-Id: I0539047a1b24c13ef278695737cdba3b9344c820
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/173703
Reviewed-on: http://review.coreboot.org/4888
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Tested-by: build bot (Jenkins)

1 files changed, 192 insertions, 0 deletions

diff --git a/src/cpu/x86/sipi_vector.S b/src/cpu/x86/sipi_vector.S
new file mode 100644
index 0000000000..52b12d0314
--- /dev/null
+++ b/src/cpu/x86/sipi_vector.S
@@ -0,0 +1,192 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2013 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; version 2 of
+ * the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
+ * MA 02110-1301 USA
+ */
+
+/* The SIPI vector is responsible for initializing the APs in the sytem. It
+ * loads microcode, sets up MSRs, and enables caching before calling into
+ * C code. */
+
+/* These segment selectors need to match the gdt entries in c_start.S. */
+#define CODE_SEG 0x10
+#define DATA_SEG 0x18
+
+#define IA32_UPDT_TRIG 0x79
+#define IA32_BIOS_SIGN_ID 0x8b
+
+.section ".module_parameters", "aw", @progbits
+ap_start_params:
+gdtaddr:
+.word 0 /* limit */
+.long 0 /* table */
+.word 0 /* unused */
+idt_ptr:
+.long 0
+stack_top:
+.long 0
+stack_size:
+.long 0
+microcode_lock:
+.long 0
+microcode_ptr:
+.long 0
+msr_table_ptr:
+.long 0
+msr_count:
+.long 0
+c_handler:
+.long 0
+ap_count:
+.long 0
+
+.text
+.code16
+.global ap_start
+ap_start:
+	cli
+	xorl	%eax, %eax
+	movl	%eax, %cr3    /* Invalidate TLB*/
+
+	/* On hyper threaded cpus, invalidating the cache here is
+	 * very very bad.  Don't.
+	 */
+
+	/* setup the data segment */
+	movw	%cs, %ax
+	movw	%ax, %ds
+
+	/* The gdtaddr needs to be releative to the data segment in order
+	 * to properly dereference it. The .text section comes first in an
+	 * rmodule so ap_start can be used as a proxy for the load address. */
+	movl	$(gdtaddr), %ebx
+	sub	$(ap_start), %ebx
+
+	data32 lgdt (%ebx)
+
+	movl	%cr0, %eax
+	andl	$0x7FFAFFD1, %eax /* PG,AM,WP,NE,TS,EM,MP = 0 */
+	orl	$0x60000001, %eax /* CD, NW, PE = 1 */
+	movl	%eax, %cr0
+
+	ljmpl	$CODE_SEG, $1f
+1:
+	.code32
+	movw	$DATA_SEG, %ax
+	movw	%ax, %ds
+	movw	%ax, %es
+	movw	%ax, %ss
+	movw	%ax, %fs
+	movw	%ax, %gs
+
+	/* Load the Interrupt descriptor table */
+	mov	idt_ptr, %ebx
+	lidt	(%ebx)
+
+	/* Obtain cpu number. */
+	movl	ap_count, %eax
+1:
+	movl	%eax, %ecx
+	inc	%ecx
+	lock cmpxchg %ecx, ap_count
+	jnz	1b
+
+	/* Setup stacks for each CPU. */
+	movl	stack_size, %eax
+	mul	%ecx
+	movl	stack_top, %edx
+	subl	%eax, %edx
+	mov	%edx, %esp
+	/* Save cpu number. */
+	mov	%ecx, %esi
+
+	/* Determine if one should check microcode versions. */
+	mov	microcode_ptr, %edi
+	test	%edi, %edi
+	jz	microcode_done /* Bypass if no microde exists. */
+
+	/* Get the Microcode version. */
+	mov	$1, %eax
+	cpuid
+	mov	$IA32_BIOS_SIGN_ID, %ecx
+	rdmsr
+	/* If something already loaded skip loading again. */
+	test	%edx, %edx
+	jnz	microcode_done
+
+	/* Determine if parallel microcode loading is allowed. */
+	cmp	$0xffffffff, microcode_lock
+	je	load_microcode
+
+	/* Protect microcode loading. */
+lock_microcode:
+	lock bts $0, microcode_lock
+	jc	lock_microcode
+
+load_microcode:
+	/* Load new microcode. */
+	mov	$IA32_UPDT_TRIG, %ecx
+	xor	%edx, %edx
+	mov	%edi, %eax
+	/* The microcode pointer is passed in pointing to the header. Adjust
+	 * pointer to reflect the payload (header size is 48 bytes). */
+	add	$48, %eax
+	pusha
+	wrmsr
+	popa
+
+	/* Unconditionally unlock microcode loading. */
+	cmp	$0xffffffff, microcode_lock
+	je	microcode_done
+
+	xor	%eax, %eax
+	mov	%eax, microcode_lock
+
+microcode_done:
+	/*
+	 * Load MSRs. Each entry in the table consists of:
+	 * 0: index,
+	 * 4: value[31:0]
+	 * 8: value[63:32]
+	 */
+	mov	msr_table_ptr, %edi
+	mov	msr_count, %ebx
+	test	%ebx, %ebx
+	jz	1f
+load_msr:
+	mov	(%edi), %ecx
+	mov	4(%edi), %eax
+	mov	8(%edi), %edx
+	wrmsr
+	add	$12, %edi
+	dec	%ebx
+	jnz	load_msr
+
+1:
+	/* Enable caching. */
+	mov	%cr0, %eax
+	and	$0x9fffffff, %eax /* CD, NW = 0 */
+	mov	%eax, %cr0
+
+	/* c_handler(cpu_num) */
+	push	%esi	/* cpu_num */
+	mov	c_handler, %eax
+	call	*%eax
+halt_jump:
+	hlt
+	jmp	halt_jump