[coreboot-gerrit] Change in coreboot[master]: lib/fmap: Disable pre-RAM cache for FSP 1.0

[Julius Werner (Code Review)]

Hello Arthur Heymans, Patrick Georgi,

I'd like you to do a code review. Please visit

https://review.coreboot.org/c/coreboot/+/36937

to review the following change.

Change subject: lib/fmap: Disable pre-RAM cache for FSP 1.0
......................................................................

lib/fmap: Disable pre-RAM cache for FSP 1.0

Due to the way CAR teardown is handled in FSP 1.0, the results of
car_get_var_ptr() aren't always reliable, which can break things when
running with FMAP cache. It might be possible to fix this but would make
the code rather complicated, so let's just disable the feature on these
platforms and hope they die out soon.

Change-Id: I7ffb1b8b08a7ca3fe8d53dc827e2c8521da064c7
Signed-off-by: Julius Werner 
---
M src/lib/fmap.c
1 file changed, 3 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/37/36937/1

diff --git a/src/lib/fmap.c b/src/lib/fmap.c
index 4b4179c..b54322c 100644
--- a/src/lib/fmap.c
+++ b/src/lib/fmap.c
@@ -60,6 +60,9 @@

static void setup_preram_cache(struct mem_region_device *cache_mrdev)
 {
+	if (CONFIG(PLATFORM_USES_FSP1_0))
+		return;	/* FSP 1.0's CAR_GLOBAL support cannot handle this. */
+
    if (!ENV_ROMSTAGE_OR_BEFORE) {
    	/* We get here if ramstage makes an FMAP access before calling
    	   cbmem_initialize(). We should avoid letting it come to that,