Change in coreboot[master]: lib/cbfs: Enable cbfs_cache for x86

[Raul Rangel (Code Review)]

Raul Rangel has submitted this change. ( https://review.coreboot.org/c/coreboot/+/56577 )

Change subject: lib/cbfs: Enable cbfs_cache for x86
......................................................................

lib/cbfs: Enable cbfs_cache for x86

The reason cbfs_cache was disabled on x86 was due to the lack of
.data sections in the pre-RAM stages. By using
ENV_STAGE_HAS_DATA_SECTION we enable x86 to start using the cbfs_cache.

We still need to add a cbfs_cache region into the memlayout for it to
be enabled.

BUG=b:179699789
TEST=Build guybrush and verify cbfs_cache.size == 0.

Suggested-by: Julius Werner 
Signed-off-by: Raul E Rangel 
Change-Id: I74434ef9250ff059e7587147b1456aeabbee33aa
Reviewed-on: https://review.coreboot.org/c/coreboot/+/56577
Tested-by: build bot (Jenkins) 
Reviewed-by: Julius Werner 
Reviewed-by: Karthik Ramasubramanian 
---
M src/include/cbfs.h
M src/lib/cbfs.c
2 files changed, 12 insertions(+), 11 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Julius Werner: Looks good to me, approved
  Karthik Ramasubramanian: Looks good to me, approved

diff --git a/src/include/cbfs.h b/src/include/cbfs.h
index f27c60f..0d8ac60 100644
--- a/src/include/cbfs.h
+++ b/src/include/cbfs.h
@@ -111,12 +111,7 @@

/*
  * The shared memory pool for backing mapped CBFS files, and other CBFS allocation needs.
- * On x86 platforms, this would only be needed to transparently map compressed files, but it
- * would require a permanent CBMEM carveout to be safe to use during S3 resume. Since it's not
- * clear whether this feature is necessary or worth the wasted memory, it is currently disabled
- * but could be added behind a Kconfig later if desired.
  */
-#define CBFS_CACHE_AVAILABLE (!CONFIG(ARCH_X86))
 extern struct mem_pool cbfs_cache;

/*
diff --git a/src/lib/cbfs.c b/src/lib/cbfs.c
index 52f7373..322f161 100644
--- a/src/lib/cbfs.c
+++ b/src/lib/cbfs.c
@@ -18,8 +18,11 @@
 #include <symbols.h>
 #include <timestamp.h>

-#if CBFS_CACHE_AVAILABLE
+#if ENV_STAGE_HAS_DATA_SECTION
 struct mem_pool cbfs_cache = MEM_POOL_INIT(_cbfs_cache, REGION_SIZE(cbfs_cache));
+#else
+struct mem_pool cbfs_cache = MEM_POOL_INIT(NULL, 0);
+#endif

static void switch_to_postram_cache(int unused)
 {
@@ -28,7 +31,6 @@
    		      REGION_SIZE(postram_cbfs_cache));
 }
 ROMSTAGE_CBMEM_INIT_HOOK(switch_to_postram_cache);
-#endif

cb_err_t cbfs_boot_lookup(const char *name, bool force_ro,
    		  union cbfs_mdata *mdata, struct region_device *rdev)
@@ -111,8 +113,7 @@
     * that requires a free() for the boot_device, they need to implement it via the
     * cbfs_cache mem_pool.
     */
-	if (CBFS_CACHE_AVAILABLE)
-		mem_pool_free(&cbfs_cache, mapping);
+	mem_pool_free(&cbfs_cache, mapping);
 }

int cbfs_locate_file_in_region(struct cbfsf *fh, const char *region_name,
@@ -319,8 +320,13 @@
    	}

return mapping;
-	} else if (!CBFS_CACHE_AVAILABLE) {
-		ERROR("Cannot map compressed file %s on x86\n", mdata.h.filename);
+	} else if (!cbfs_cache.size) {
+		/*
+		 * In order to use the cbfs_cache you need to add a CBFS_CACHE to your
+		 * memlayout. For stages that don't have .data sections (x86 pre-RAM),
+		 * it is not possible to add a CBFS_CACHE.
+		 */
+		ERROR("Cannot map compressed file %s without cbfs_cache\n", mdata.h.filename);
    	return NULL;
    } else {
    	loc = mem_pool_alloc(&cbfs_cache, size);