cpu/intel/slot_1: Switch to different CAR setup

This moves CAR stack under variable MTRRs and removes
old CAR code that used complex fixed MTRRs and placed
stack in low memory.

Change-Id: I75ec842ae3b6771cc3f7ff652adbe386c03b9a5f
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Signed-off-by: Keith Hui <buurin@gmail.com>
Reviewed-on: https://review.coreboot.org/26586
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

1 files changed, 34 insertions, 0 deletions

diff --git a/src/northbridge/intel/i440bx/ram_calc.c b/src/northbridge/intel/i440bx/ram_calc.c
index c9bfc2da9f..dc294f14c6 100644
--- a/src/northbridge/intel/i440bx/ram_calc.c
+++ b/src/northbridge/intel/i440bx/ram_calc.c
@@ -17,7 +17,11 @@
 
 #include <arch/io.h>
 #include <cbmem.h>
+#include <console/console.h>
 #include <commonlib/helpers.h>
+#include <cpu/intel/romstage.h>
+#include <cpu/x86/mtrr.h>
+#include <program_loading.h>
 #include "i440bx.h"
 
 void *cbmem_top(void)
@@ -62,3 +66,33 @@ void *cbmem_top(void)
 	}
 	return (void *)tom;
 }
+
+#define ROMSTAGE_RAM_STACK_SIZE 0x5000
+
+/* setup_stack_and_mtrrs() determines the stack to use after
+ * cache-as-ram is torn down as well as the MTRR settings to use. */
+void *setup_stack_and_mtrrs(void)
+{
+	struct postcar_frame pcf;
+	uintptr_t top_of_ram;
+
+	if (postcar_frame_init(&pcf, ROMSTAGE_RAM_STACK_SIZE))
+		die("Unable to initialize postcar frame.\n");
+
+	/* Cache the ROM as WP just below 4GiB. */
+	postcar_frame_add_mtrr(&pcf, CACHE_ROM_BASE, CACHE_ROM_SIZE,
+		MTRR_TYPE_WRPROT);
+
+	/* Cache RAM as WB from 0 -> CACHE_TMP_RAMTOP. */
+	postcar_frame_add_mtrr(&pcf, 0, CACHE_TMP_RAMTOP, MTRR_TYPE_WRBACK);
+
+	/* Cache CBMEM region as WB. */
+	top_of_ram = (uintptr_t)cbmem_top();
+	postcar_frame_add_mtrr(&pcf, top_of_ram - 8*MiB, 8*MiB,
+		MTRR_TYPE_WRBACK);
+
+	/* Save the number of MTRRs to setup. Return the stack location
+	 * pointing to the number of MTRRs.
+	 */
+	return postcar_commit_mtrrs(&pcf);
+}