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>

src/lib/cbfs.c

@@ -187,6 +187,18 @@ size_t cbfs_boot_load_struct(const char *name, void *buf, size_t buf_size)
 					buf, buf_size, compression_algo);
 }
 
+size_t cbfs_prog_stage_section(struct prog *pstage, uintptr_t *base)
+{
+	struct cbfs_stage stage;
+	const struct region_device *fh = prog_rdev(pstage);
+
+	if (rdev_readat(fh, &stage, 0, sizeof(stage)) != sizeof(stage))
+		return 0;
+
+	*base = (uintptr_t)stage.load;
+	return stage.memlen;
+}
+
 int cbfs_prog_stage_load(struct prog *pstage)
 {
 	struct cbfs_stage stage;

src/lib/prog_loaders.c

@@ -110,6 +110,18 @@ static int load_relocatable_ramstage(struct prog *ramstage)
 	return rmodule_stage_load(&rmod_ram);
 }
 
+static int load_nonrelocatable_ramstage(struct prog *ramstage)
+{
+	if (IS_ENABLED(CONFIG_HAVE_ACPI_RESUME)) {
+		uintptr_t base = 0;
+		size_t size = cbfs_prog_stage_section(ramstage, &base);
+		if (size)
+			backup_ramstage_section(base, size);
+	}
+
+	return cbfs_prog_stage_load(ramstage);
+}
+
 void run_ramstage(void)
 {
 	struct prog ramstage =
@@ -135,7 +147,7 @@ void run_ramstage(void)
 	if (IS_ENABLED(CONFIG_RELOCATABLE_RAMSTAGE)) {
 		if (load_relocatable_ramstage(&ramstage))
 			goto fail;
-	} else if (cbfs_prog_stage_load(&ramstage))
+	} else if (load_nonrelocatable_ramstage(&ramstage))
 		goto fail;
 
 	stage_cache_add(STAGE_RAMSTAGE, &ramstage);