ACPI S3: Depend on RELOCATABLE_RAMSTAGE

With RELOCATABLE_RAMSTAGE, S3 resume path only uses
memory that is reserved from OS. So there is no need
for low memory backup and recovery.

Change-Id: If7f83711685ac445abf4cd1aa6b66c3391e0e554
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/26834
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

3 files changed, 2 insertions, 115 deletions

diff --git a/src/arch/x86/acpi_s3.c b/src/arch/x86/acpi_s3.c
index decaf2b5ff..ff9d60c729 100644
--- a/src/arch/x86/acpi_s3.c
+++ b/src/arch/x86/acpi_s3.c
@@ -70,124 +70,20 @@ void acpi_fail_wakeup(void)
 }
 #endif /* ENV_RAMSTAGE */
 
-struct resume_backup {
-	uint64_t cbmem;
-	uint64_t lowmem;
-	uint64_t size;
-	uint8_t valid;
-};
-
-#define BACKUP_PAGE_SZ 4096
-
-static int backup_create_or_update(struct resume_backup *backup_mem,
-				uintptr_t base, size_t size)
-{
-	uintptr_t top;
-
-	/* Align backup region to complete pages. */
-	top = ALIGN_UP(base + size, BACKUP_PAGE_SZ);
-	base = ALIGN_DOWN(base, BACKUP_PAGE_SZ);
-	size = top - base;
-
-	/* Cannot extend existing region, should not happen. */
-	if (backup_mem && (backup_mem->size < size))
-		return -1;
-
-	/* Allocate backup with room for header. */
-	if (!backup_mem) {
-		size_t header_sz = ALIGN_UP(sizeof(*backup_mem),
-			BACKUP_PAGE_SZ);
-		backup_mem = cbmem_add(CBMEM_ID_RESUME, header_sz + size);
-		if (!backup_mem)
-			return -1;
-
-		/* Container starts from boundary after header. */
-		backup_mem->cbmem = (uintptr_t)backup_mem + header_sz;
-	}
-
-	backup_mem->valid = 0;
-	backup_mem->lowmem = base;
-	backup_mem->size = size;
-	return 0;
-}
-
-void backup_ramstage_section(uintptr_t base, size_t size)
-{
-	struct resume_backup *backup_mem = cbmem_find(CBMEM_ID_RESUME);
-
-	/* For first boot we exit here as CBMEM_ID_RESUME is only
-	 * created late in ramstage with acpi_prepare_resume_backup().
-	 */
-	if (!backup_mem)
-		return;
-
-	/* Check that the backup is not done twice. */
-	if (backup_mem->valid)
-		return;
-
-	/* When we are called from ramstage loader, update header with
-	 * properties of the ramstage we will load.
-	 */
-	if (backup_create_or_update(backup_mem, base, size) < 0)
-		return;
-
-	/* Back up the OS-controlled memory where ramstage will be loaded. */
-	memcpy((void *)(uintptr_t)backup_mem->cbmem,
-		(void *)(uintptr_t)backup_mem->lowmem,
-		(size_t)backup_mem->size);
-	backup_mem->valid = 1;
-}
-
-/* Let's prepare the ACPI S3 Resume area now already, so we can rely on
- * it being there during reboot time. If this fails, ACPI resume will
- * be disabled. We assume that ramstage does not change while in suspend,
- * so base and size of the currently running ramstage are used
- * for allocation.
- */
-void acpi_prepare_resume_backup(void)
-{
-	if (!acpi_s3_resume_allowed())
-		return;
-
-	if (CONFIG(RELOCATABLE_RAMSTAGE))
-		return;
-
-	backup_create_or_update(NULL, (uintptr_t)_program,
-				REGION_SIZE(program));
-}
-
 #define WAKEUP_BASE 0x600
 
-asmlinkage void (*acpi_do_wakeup)(uintptr_t vector, u32 backup_source,
-	u32 backup_target, u32 backup_size) = (void *)WAKEUP_BASE;
+asmlinkage void (*acpi_do_wakeup)(uintptr_t vector) = (void *)WAKEUP_BASE;
 
 extern unsigned char __wakeup;
 extern unsigned int __wakeup_size;
 
 static void acpi_jump_to_wakeup(void *vector)
 {
-	uintptr_t source = 0, target = 0;
-	size_t size = 0;
-
 	if (!acpi_s3_resume_allowed()) {
 		printk(BIOS_WARNING, "ACPI: S3 resume not allowed.\n");
 		return;
 	}
 
-	if (!CONFIG(RELOCATABLE_RAMSTAGE)) {
-		struct resume_backup *backup_mem = cbmem_find(CBMEM_ID_RESUME);
-		if (backup_mem && backup_mem->valid) {
-			backup_mem->valid = 0;
-			target = backup_mem->lowmem;
-			source = backup_mem->cbmem;
-			size = backup_mem->size;
-		} else  {
-			printk(BIOS_WARNING, "ACPI: Backup memory missing. "
-				"No S3 resume.\n");
-			return;
-		}
-	}
-
 	/* Copy wakeup trampoline in place. */
 	memcpy((void *)WAKEUP_BASE, &__wakeup, __wakeup_size);
 
@@ -195,7 +91,7 @@ static void acpi_jump_to_wakeup(void *vector)
 
 	timestamp_add_now(TS_ACPI_WAKE_JUMP);
 
-	acpi_do_wakeup((uintptr_t)vector, source, target, size);
+	acpi_do_wakeup((uintptr_t)vector);
 }
 
 void __weak mainboard_suspend_resume(void)
diff --git a/src/arch/x86/include/arch/acpi.h b/src/arch/x86/include/arch/acpi.h
index 670948a1d1..16e4269dde 100644
--- a/src/arch/x86/include/arch/acpi.h
+++ b/src/arch/x86/include/arch/acpi.h
@@ -934,7 +934,6 @@ unsigned long acpi_create_hest_error_source(acpi_hest_t *hest,
 /* For ACPI S3 support. */
 void acpi_fail_wakeup(void);
 void acpi_resume(void *wake_vec);
-void acpi_prepare_resume_backup(void);
 void mainboard_suspend_resume(void);
 void *acpi_find_wakeup_vector(void);
 
diff --git a/src/arch/x86/wakeup.S b/src/arch/x86/wakeup.S
index ba502fefa5..1362eb4a18 100644
--- a/src/arch/x86/wakeup.S
+++ b/src/arch/x86/wakeup.S
@@ -64,14 +64,6 @@ __wakeup:
 	shr	$4, %eax
 	movw	%ax, (__wakeup_segment)
 
-	/* Then overwrite coreboot with our backed up memory */
-	cld
-	movl	8(%esp), %esi
-	movl	12(%esp), %edi
-	movl	16(%esp), %ecx
-	shrl	$2, %ecx
-	rep	movsl
-
 	/* Activate the right segment descriptor real mode. */
 	ljmp	$0x28, $RELOCATED(1f)
 1: