drivers/intel/fsp2_0: add option to compress FSP-M in cbfs

Allow the ability for chipset or mainboard to choose to
compress FSP-M in cbfs using LZMA or LZ4 routines. However, only
non-XIP platforms will support FSP-M compression. Since the main
cbfs decompression paths are utilized add the appropriate checks
for including compression algorithms under the FSP-M compression
options.

On picasso FSP-M (debug builds) the following savings were measured:
no-compression:
	fspm.bin	720896	none
FSP_COMPRESS_FSP_M_LZ4:
	fspm.bin	138379	LZ4  (720896 decompressed)	-80%
FSP_COMPRESS_FSP_M_LZMA:
	fspm.bin	98921	LZMA (720896 decompressed)	-86%

BUG=b:155322763,b:150746858,b:152909132

Change-Id: I5c88510c134b56a36ff1cd97a64b51ab2fea0ab0
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41450
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/drivers/intel/fsp2_0/util.c

@@ -119,6 +119,21 @@ void fsp_handle_reset(uint32_t status)
 	}
 }
 
+static inline bool fspm_env(void)
+{
+	if (ENV_ROMSTAGE)
+		return true;
+	return false;
+}
+
+static inline bool fspm_xip(void)
+{
+	/* FSP-M is assumed to be loaded in romstage. */
+	if (fspm_env() && CONFIG(FSP_M_XIP))
+		return true;
+	return false;
+}
+
 static void *fsp_get_dest_and_load(struct fsp_load_descriptor *fspld, size_t size,
 				const struct region_device *source_rdev,
 				uint32_t compression_algo)
@@ -130,12 +145,20 @@ static void *fsp_get_dest_and_load(struct fsp_load_descriptor *fspld, size_t siz
 		return NULL;
 	}
 
+	/* Don't load when executing in place. */
+	if (fspm_xip())
+		return dest;
+
 	if (cbfs_load_and_decompress(source_rdev, 0, region_device_sz(source_rdev),
 			dest, size, compression_algo) != size) {
 		printk(BIOS_ERR, "Failed to load FSP component.\n");
 		return NULL;
 	}
 
+	/* Don't allow FSP-M relocation. */
+	if (fspm_env())
+		return dest;
+
 	if (fsp_component_relocate((uintptr_t)dest, dest, size) < 0) {
 		printk(BIOS_ERR, "Unable to relocate FSP component!\n");
 		return NULL;