soc/intel/braswell: Use common cpu/intel/car code

The code in cpu/intel/car/romstage.c Does most of the things like
setting up timestamps, stack guards, entering postcar.

A functional difference is that the FSP header is searched for twice
instead of passed from the CAR entry to the C code. When using
C_ENVIRONMENT_BOOTBLOCK this needs to be done anyway (or a special
linker symbol kept across multiple stages is needed, which is likely
not worth the speedup).

Change-Id: I0f03e5a808f00157fdd807b104417a54e4bde7b2
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32963
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>

src/drivers/intel/fsp1_1/cache_as_ram.inc

@@ -31,11 +31,11 @@
 	 * EBX, EDI, ESI, EBP, MM0, MM1
 	 *
 	 * Shift values to release MM2.
-	 * mm0 -> edi:  BIST value
+	 * mm0 -> ebx:  BIST value
 	 * mm1 -> mm0:  low 32-bits of TSC value
 	 * mm2 -> mm1:  high 32-bits of TSC value
 	 */
-	movd	%mm0, %edi
+	movd	%mm0, %ebx
 	movd	%mm1, %eax
 	movd	%eax, %mm0
 	movd	%mm2, %eax
@@ -79,8 +79,8 @@ find_fsp_ret:
 	/*
 	 *       BIST value is zero
 	 * eax:  TempRamInitApi address
+	 * ebx:  BIST value
 	 * ebp:  FSP_INFO_HEADER address
-	 * edi:  BIST value
 	 * esi:  Not used
 	 * mm0:  low 32-bits of TSC value
 	 * mm1:  high 32-bits of TSC value
@@ -90,13 +90,12 @@ find_fsp_ret:
 	jmp	*%eax
 
 CAR_init_done:
-	addl	$4, %esp
 
 	/*
 	 * ebp:  FSP_INFO_HEADER address
+	 * ebx:  BIST value
 	 * ecx:  Temp RAM base
 	 * edx:  Temp RAM top
-	 * edi:  BIST value
 	 * mm0:  low 32-bits of TSC value
 	 * mm1:  high 32-bits of TSC value
 	 */
@@ -109,43 +108,42 @@ CAR_init_done:
 
 	/*
 	 * ebp:  FSP_INFO_HEADER address
+	 * ebx:  BIST value
 	 * ecx:  Temp RAM base
 	 * edx:  Temp RAM top
-	 * edi:  BIST value
 	 * esp:  Top of stack in temp RAM
 	 * mm0:  low 32-bits of TSC value
 	 * mm1:  high 32-bits of TSC value
 	 */
 
-	/* Create cache_as_ram_params on stack */
-	pushl	%edx	/* bootloader CAR end */
-	pushl	%ecx	/* bootloader CAR begin */
-	pushl	%ebp	/* FSP_INFO_HEADER */
-	pushl	%edi	/* bist */
-	movd	%mm1, %eax
-	pushl	%eax	/* tsc[63:32] */
-	movd	%mm0, %eax
-	pushl	%eax	/* tsc[31:0] */
-	pushl	%esp	/* pointer to cache_as_ram_params */
-
-	/* Save FSP_INFO_HEADER location in ebx */
-	mov	%ebp, %ebx
-
 	/* coreboot assumes stack/heap region will be zero */
 	cld
 	movl	%ecx, %edi
 	neg	%ecx
-	/* Only clear up to current stack value. */
+	/* Clear up to Temp Ram top. */
-	add	%esp, %ecx
+	add	%edx, %ecx
 	shrl	$2, %ecx
 	xorl	%eax, %eax
 	rep	stosl
 
+	/* Need to align stack to 16 bytes at call instruction. Account for
+	the pushes below. */
+	andl	$0xfffffff0, %esp
+	subl	$4, %esp
+
+	/* Push BIST and initial timestamp on the stack */
+	pushl	%ebx	/* bist */
+	movd	%mm1, %eax
+	pushl	%eax	/* tsc[63:32] */
+	movd	%mm0, %eax
+	pushl	%eax	/* tsc[31:0] */
+
 before_romstage:
 	post_code(0x2A)
 
-	/* Call cache_as_ram_main(struct cache_as_ram_params *) */
+	/* Call bootblock_c_entry_bist(uint64_t base_timestamp, uint32_t bist)
-	call	cache_as_ram_main
+	   in cpu/intel/car/romstage.c */
+	call	bootblock_c_entry_bist
 
 	movb	$0x69, %ah
 	jmp	.Lhlt

src/drivers/intel/fsp1_1/car.c

@@ -94,74 +94,25 @@ void platform_enter_postcar(void)
 	run_postcar_phase(&pcf);
 }
 
-/* This is the romstage C entry for platforms without
+/* This is the romstage entry called from cpu/intel/car/romstage.c */
-   CONFIG_C_ENVIRONMENT_BOOTBLOCK */
-asmlinkage void cache_as_ram_main(struct cache_as_ram_params *car_params)
-{
-	int i;
-	const int num_guards = 4;
-	const u32 stack_guard = 0xdeadbeef;
-	u32 *stack_base;
-	u32 size;
-
-	/* Size of unallocated CAR. */
-	size = _car_region_end - _car_relocatable_data_end;
-	size = ALIGN_DOWN(size, 16);
-
-	stack_base = (u32 *)(_car_region_end - size);
-
-	for (i = 0; i < num_guards; i++)
-		stack_base[i] = stack_guard;
-
-	/* Initialize timestamp book keeping only once. */
-	timestamp_init(car_params->tsc);
-
-	/* Call into pre-console init code then initialize console. */
-	car_soc_pre_console_init();
-	car_mainboard_pre_console_init();
-	console_init();
-
-	printk(BIOS_DEBUG, "FSP TempRamInit successful\n");
-
-	printk(BIOS_SPEW, "bist: 0x%08x\n", car_params->bist);
-	printk(BIOS_SPEW, "tsc: 0x%016llx\n", car_params->tsc);
-
-	display_mtrrs();
-
-	if (car_params->bootloader_car_start != CONFIG_DCACHE_RAM_BASE
-	    || car_params->bootloader_car_end != (CONFIG_DCACHE_RAM_BASE
-						  + CONFIG_DCACHE_RAM_SIZE)) {
-		printk(BIOS_INFO, "CAR mismatch: %08x--%08x vs %08lx--%08lx\n",
-		       CONFIG_DCACHE_RAM_BASE,
-		       CONFIG_DCACHE_RAM_BASE + CONFIG_DCACHE_RAM_SIZE,
-		       (long)car_params->bootloader_car_start,
-		       (long)car_params->bootloader_car_end);
-	}
-
-	car_soc_post_console_init();
-	car_mainboard_post_console_init();
-
-	cache_as_ram_stage_main(car_params->fih);
-
-	/* Check the stack. */
-	for (i = 0; i < num_guards; i++) {
-		if (stack_base[i] == stack_guard)
-			continue;
-		printk(BIOS_DEBUG, "Smashed stack detected in romstage!\n");
-	}
-
-	/* we don't return here */
-	platform_enter_postcar();
-}
-
-/* This is the entry for platforms with CONFIG_C_ENVIRONMENT_BOOTBLOCK
-   called from cpu/intel/car/romstage.c */
 void mainboard_romstage_entry(unsigned long bist)
 {
 	/* Need to locate the current FSP_INFO_HEADER. The cache-as-ram
 	 * is still enabled. We can directly access work buffer here. */
 	struct prog fsp = PROG_INIT(PROG_REFCODE, "fsp.bin");
 
+	if (!CONFIG(C_ENVIRONMENT_BOOTBLOCK)) {
+		/* Call into pre-console init code then initialize console. */
+		car_soc_pre_console_init();
+		car_mainboard_pre_console_init();
+		console_init();
+
+		display_mtrrs();
+
+		car_soc_post_console_init();
+		car_mainboard_post_console_init();
+	}
+
 	if (prog_locate(&fsp))
 		die_with_post_code(POST_INVALID_CBFS, "Unable to locate fsp.bin");
 

src/drivers/intel/fsp1_1/include/fsp/car.h

@@ -20,17 +20,6 @@
 #include <fsp/api.h>
 #include <stdint.h>
 
-/* cache-as-ram support for FSP 1.1. */
-struct cache_as_ram_params {
-	uint64_t tsc;
-	uint32_t bist;
-	FSP_INFO_HEADER *fih;
-	uintptr_t bootloader_car_start;
-	uintptr_t bootloader_car_end;
-};
-
-/* Entry points from the cache-as-ram assembly code. */
-asmlinkage void cache_as_ram_main(struct cache_as_ram_params *car_params);
 /* Per stage calls from the above two functions. The void * return from
  * cache_as_ram_stage_main() is the stack pointer to use in RAM after
  * exiting cache-as-ram mode. */

src/soc/intel/braswell/romstage/Makefile.inc

@@ -1,2 +1,3 @@
+romstage-y += ../../../../cpu/intel/car/romstage.c
 romstage-y += pmc.c
 romstage-y += romstage.c