soc/intel/skylake: use postcar stage for fsp 2.0

Utilize the postcar stage for tearing down CAR and initializing
the MTRRs once ram is up. This flow is consistent with apollolake
and allows CAR_GLOBAL variables to be directly accessed and no
need for migrating CAR_GLOBAL variables as romstage doesn't
run with and without CAR being available.

Change-Id: I76de447710ae1d405886eb9420dc4064aa26eccc
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/19335
Tested-by: build bot (Jenkins)
Reviewed-by: Furquan Shaikh <furquan@google.com>

3 files changed, 2 insertions, 135 deletions

diff --git a/src/soc/intel/skylake/romstage/Makefile.inc b/src/soc/intel/skylake/romstage/Makefile.inc
index 47c8c7e39c..7dfbd35610 100644
--- a/src/soc/intel/skylake/romstage/Makefile.inc
+++ b/src/soc/intel/skylake/romstage/Makefile.inc
@@ -1,7 +1,6 @@
 verstage-y += power_state.c
 
 romstage-$(CONFIG_PLATFORM_USES_FSP1_1) += car_stage.S
-romstage-$(CONFIG_PLATFORM_USES_FSP2_0) += car_stage_fsp20.S
 romstage-y += pmc.c
 romstage-y += power_state.c
 romstage-$(CONFIG_PLATFORM_USES_FSP1_1) += romstage.c
diff --git a/src/soc/intel/skylake/romstage/car_stage_fsp20.S b/src/soc/intel/skylake/romstage/car_stage_fsp20.S
deleted file mode 100644
index 5ef8bd61bf..0000000000
--- a/src/soc/intel/skylake/romstage/car_stage_fsp20.S
+++ /dev/null
@@ -1,132 +0,0 @@
-/*
- * This file is part of the coreboot project.
- *
- * Copyright (C) 2015-2016 Intel Corporation
- *
- * 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.
- *
- */
-
-#include <rules.h>
-#include <cpu/x86/mtrr.h>
-#include <cpu/x86/cache.h>
-#include <cpu/x86/post_code.h>
-
-.section ".text"
-.global car_stage_entry
-
-car_stage_entry:
-
-	/* Enter the C code */
-	call	car_stage_c_entry
-
-/*
- * Car teardown
- */
-	/*
-	 * eax:  New stack address
-	 */
-
-	/* Switch to the stack in RAM */
-	movl	%eax, %esp
-
-	/* chipset_teardown_car() is expected to disable cache-as-ram. */
-	call	chipset_teardown_car
-
-	/* Display the MTRRs */
-	call	soc_display_mtrrs
-
-	/*
-	 * The stack contents are initialized in src/soc/intel/common/stack.c
-	 * to be the following:
-	 *
-	 *		*
-	 *		*
-	 *		*
-	 *  +36: MTRR mask 1 63:32
-	 *  +32: MTRR mask 1 31:0
-	 *  +28: MTRR base 1 63:32
-	 *  +24: MTRR base 1 31:0
-	 *  +20: MTRR mask 0 63:32
-	 *  +16: MTRR mask 0 31:0
-	 *  +12: MTRR base 0 63:32
-	 *   +8: MTRR base 0 31:0
-	 *   +4: Number of MTRRs to setup (described above)
-	 *   +0: Number of variable MTRRs to clear
-	 */
-
-	/* Clear all of the variable MTRRs. */
-	popl	%ebx
-	movl	$MTRR_PHYS_BASE(0), %ecx
-	clr	%eax
-	clr	%edx
-
-1:
-	testl	%ebx, %ebx
-	jz	1f
-	wrmsr			/* Write MTRR base. */
-	inc	%ecx
-	wrmsr			/* Write MTRR mask. */
-	inc	%ecx
-	dec	%ebx
-	jmp	1b
-
-1:
-	/* Get number of MTRRs. */
-	popl	%ebx
-	movl	$MTRR_PHYS_BASE(0), %ecx
-2:
-	testl	%ebx, %ebx
-	jz	2f
-
-	/* Low 32 bits of MTRR base. */
-	popl	%eax
-	/* Upper 32 bits of MTRR base. */
-	popl	%edx
-	/* Write MTRR base. */
-	wrmsr
-	inc	%ecx
-	/* Low 32 bits of MTRR mask. */
-	popl	%eax
-	/* Upper 32 bits of MTRR mask. */
-	popl	%edx
-	/* Write MTRR mask. */
-	wrmsr
-	inc	%ecx
-
-	dec	%ebx
-	jmp	2b
-2:
-
-	post_code(0x39)
-
-	/* And enable cache again after setting MTRRs. */
-	movl	%cr0, %eax
-	andl	$~(CR0_CacheDisable | CR0_NoWriteThrough), %eax
-	movl	%eax, %cr0
-
-	post_code(0x3a)
-
-	/* Enable MTRR. */
-	movl	$MTRR_DEF_TYPE_MSR, %ecx
-	rdmsr
-	orl	$MTRR_DEF_TYPE_EN, %eax
-	wrmsr
-
-	post_code(0x3b)
-
-	/* Invalidate the cache again. */
-	invd
-
-__main:
-	post_code(POST_PREPARE_RAMSTAGE)
-	cld			/* Clear direction flag. */
-
-	call	copy_and_run
diff --git a/src/soc/intel/skylake/romstage/romstage_fsp20.c b/src/soc/intel/skylake/romstage/romstage_fsp20.c
index fbc5fe1c53..4530190b07 100644
--- a/src/soc/intel/skylake/romstage/romstage_fsp20.c
+++ b/src/soc/intel/skylake/romstage/romstage_fsp20.c
@@ -115,7 +115,7 @@ static void save_dimm_info(void)
 	printk(BIOS_DEBUG, "%d DIMMs found\n", mem_info->dimm_cnt);
 }
 
-asmlinkage void *car_stage_c_entry(void)
+asmlinkage void car_stage_entry(void)
 {
 	bool s3wake;
 	struct postcar_frame pcf;
@@ -170,7 +170,7 @@ asmlinkage void *car_stage_c_entry(void)
 	postcar_frame_add_mtrr(&pcf, 0xFFFFFFFF - CONFIG_ROM_SIZE + 1,
 				CONFIG_ROM_SIZE, MTRR_TYPE_WRPROT);
 
-	return postcar_commit_mtrrs(&pcf);
+	run_postcar_phase(&pcf);
 }
 
 static void cpu_flex_override(FSP_M_CONFIG *m_cfg)