soc/intel/apollolake: utilize postcar phase/stage

The current Apollolake flow has its code executing out of
cache-as-ram for the pre-DRAM stages. This is different from
past platforms where they were just executing-in-place against
the memory-mapped SPI flash boot media. The implication is
that when cache-as-ram needs to be torn down one needs to be
executing out of DRAM since the act of cache-as-ram going
away means the code disappears out from under the processor.
Therefore load and use the postcar infrastructure to bootstrap
this process for tearing down cache-as-ram and subsequently
loading ramstage.

Change-Id: I856f4b992dd2609b95375767bfa4fe64a267d89e
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/14141
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/soc/intel/apollolake/Kconfig

@@ -28,6 +28,7 @@ config CPU_SPECIFIC_OPTIONS
 	select PCIEXP_COMMON_CLOCK
 	select PCIEXP_CLK_PM
 	select PCIEXP_L1_SUB_STATE
+	select POSTCAR_STAGE
 	select REG_SCRIPT
 	select RELOCATABLE_RAMSTAGE	# Build fails if this is not selected
 	select SOC_INTEL_COMMON

src/soc/intel/apollolake/Makefile.inc

@@ -37,6 +37,11 @@ ramstage-y += mmap_boot.c
 ramstage-y += uart.c
 ramstage-y += northbridge.c
 
+postcar-y += exit_car.S
+postcar-y += memmap.c
+postcar-y += mmap_boot.c
+postcar-$(CONFIG_SOC_UART_DEBUG) += uart_early.c
+
 CPPFLAGS_common += -I$(src)/soc/intel/apollolake/include
 
 endif

src/soc/intel/apollolake/bootblock/cache_as_ram.S

@@ -16,8 +16,7 @@
 #include <cpu/x86/cache.h>
 #include <cpu/x86/cr.h>
 #include <cpu/x86/post_code.h>
-
-#define EVICT_CTL_MSR		0x2e0
+#include <soc/cpu.h>
 
 .global bootblock_pre_c_entry
 bootblock_pre_c_entry:
@@ -96,7 +95,7 @@ clear_var_mtrr:
 	mov	%eax, %cr0
 
 	/* Disable cache eviction (setup stage) */
-	mov	$EVICT_CTL_MSR, %ecx
+	mov	$MSR_EVICT_CTL, %ecx
 	rdmsr
 	or	$0x1, %eax
 	wrmsr
@@ -112,7 +111,7 @@ clear_var_mtrr:
 	post_code(0x27)
 
 	/* Disable cache eviction (run stage) */
-	mov	$EVICT_CTL_MSR, %ecx
+	mov	$MSR_EVICT_CTL, %ecx
 	rdmsr
 	or	$0x2, %eax
 	wrmsr

src/soc/intel/apollolake/exit_car.S

@@ -0,0 +1,47 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2016 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.
+ */
+
+#include <cpu/x86/mtrr.h>
+#include <cpu/x86/cr.h>
+#include <soc/cpu.h>
+
+.text
+.global chipset_teardown_car
+chipset_teardown_car:
+	/*
+	 * Retrieve return address from stack as it will get trashed below if
+	 * execution is utilizing the cache-as-ram stack.
+	 */
+	pop	%ebx
+
+	/* invalidate cache contents. */
+	invd
+	/* Disable MTRRs. */
+	mov	$(MTRR_DEF_TYPE_MSR), %ecx
+	rdmsr
+	and	$(~(MTRR_DEF_TYPE_EN | MTRR_DEF_TYPE_FIX_EN)), %eax
+	wrmsr
+
+	/* Knock down bit 1 then bit 0 of NEM control not combining steps. */
+	mov	$(MSR_EVICT_CTL), %ecx
+	rdmsr
+	and	$(~(1 << 1)), %eax
+	wrmsr
+	and	$(~(1 << 0)), %eax
+	wrmsr
+
+	/* Return to caller. */
+	jmp	*%ebx

src/soc/intel/apollolake/include/soc/cpu.h

@@ -13,19 +13,21 @@
 #ifndef _SOC_APOLLOLAKE_CPU_H_
 #define _SOC_APOLLOLAKE_CPU_H_
 
+#ifndef __ASSEMBLER__
 #include <cpu/x86/msr.h>
 #include <device/device.h>
 
+void apollolake_init_cpus(struct device *dev);
+#endif
+
 #define CPUID_APOLLOLAKE_A0	0x506c8
 #define CPUID_APOLLOLAKE_B0	0x506c9
 
 #define MSR_PLATFORM_INFO	0xce
 #define MSR_POWER_MISC		0x120
 #define MSR_CORE_THREAD_COUNT	0x35
+#define MSR_EVICT_CTL		0x2e0
 
 #define BASE_CLOCK_MHZ		100
 
-void apollolake_init_cpus(struct device *dev);
-
-
 #endif /* _SOC_APOLLOLAKE_CPU_H_ */

src/soc/intel/apollolake/include/soc/pci_devs.h

@@ -7,7 +7,7 @@
 #define _LPSS_PCI_DEVFN(slot, func)		PCI_DEVFN(LPSS_DEV_SLOT_##slot, func)
 
 
-#if ENV_RAMSTAGE
+#if !defined(__SIMPLE_DEVICE__)
 #include <device/device.h>
 #include <device/pci_def.h>
 #define _NB_DEV(slot)				dev_find_slot(0, _NB_DEVFN(slot))

src/soc/intel/apollolake/romstage.c

@@ -11,6 +11,7 @@
  * (at your option) any later version.
  */
 
+#include <arch/cpu.h>
 #include <arch/io.h>
 #include <arch/symbols.h>
 #include <cbfs.h>
@@ -80,6 +81,7 @@ asmlinkage void car_stage_entry(void)
 	void *hob_list_ptr;
 	struct range_entry fsp_mem;
 	struct range_entry reg_car;
+	struct postcar_frame pcf;
 
 	printk(BIOS_DEBUG, "Starting romstage...\n");
 
@@ -109,7 +111,10 @@ asmlinkage void car_stage_entry(void)
 	/* Now that CBMEM is up, save the list so ramstage can use it */
 	fsp_save_hob_list(hob_list_ptr);
 
-	run_ramstage();
+	if (postcar_frame_init(&pcf, 1*KiB))
+		die("Unable to initialize postcar frame.\n");
+
+	run_postcar_phase(&pcf);
 }
 
 static void fill_console_params(struct FSPM_UPD *mupd)