ACPI S3: Remove HIGH_MEMORY_SAVE where possible

Add implementation to use actual requirements of ramstage size
for S3 resume backup in CBMEM. The backup covers complete pages of 4 KiB.

Only the required amount of low memory is backed up when ACPI_TINY_LOWMEM_BACKUP
is selected for the platform. Enable this option for AGESA and binaryPI, other
platforms (without RELOCATABLE_RAMSTAGE) currently keep their romstage ramstack
in low memory for s3 resume path.

Change-Id: Ide7ce013f3727c2928cdb00fbcc7e7e84e859ff1
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/15255
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins)
Tested-by: Raptor Engineering Automated Test Stand <noreply@raptorengineeringinc.com>

1 files changed, 7 insertions, 5 deletions

diff --git a/src/arch/x86/include/arch/acpi.h b/src/arch/x86/include/arch/acpi.h
index 7fc1c50310..7c296480bc 100644
--- a/src/arch/x86/include/arch/acpi.h
+++ b/src/arch/x86/include/arch/acpi.h
@@ -25,12 +25,7 @@
 #ifndef __ASM_ACPI_H
 #define __ASM_ACPI_H
 
-#if IS_ENABLED(CONFIG_HAVE_ACPI_RESUME) && \
-	! IS_ENABLED(CONFIG_RELOCATABLE_RAMSTAGE)
 #define HIGH_MEMORY_SAVE	(CONFIG_RAMTOP - CONFIG_RAMBASE)
-#else
-#define HIGH_MEMORY_SAVE	0
-#endif
 
 #if IS_ENABLED(CONFIG_ACPI_INTEL_HARDWARE_SLEEP_VALUES)
 /*
@@ -688,6 +683,13 @@ static inline int acpi_s3_resume_allowed(void)
 	return IS_ENABLED(CONFIG_HAVE_ACPI_RESUME);
 }
 
+/* Return address in reserved memory where to backup low memory
+ * while platform resumes from S3 suspend. Caller is responsible of
+ * making a complete copy of the region base..base+size, with
+ * parameteres base and size that meet page alignment requirement.
+ */
+void *acpi_backup_container(uintptr_t base, size_t size);
+
 #if IS_ENABLED(CONFIG_HAVE_ACPI_RESUME)
 extern int acpi_slp_type;