ARC: mm: arc700: Don't assume 2 colours for aliasing VIPT dcache
An ARC700 customer reported linux boot crashes when upgrading to bigger
L1 dcache (64K from 32K). Turns out they had an aliasing VIPT config and
current code only assumed 2 colours, while theirs had 4. So default to 4
colours and complain if there are fewer. Ideally this needs to be a
Kconfig option, but heck that's too much of hassle for a single user.
Cc: stable@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
diff --git a/arch/arc/mm/cache.c b/arch/arc/mm/cache.c
index a0ce8ff..ec86ac0 100644
--- a/arch/arc/mm/cache.c
+++ b/arch/arc/mm/cache.c
@@ -972,11 +972,16 @@
/* check for D-Cache aliasing on ARCompact: ARCv2 has PIPT */
if (is_isa_arcompact()) {
int handled = IS_ENABLED(CONFIG_ARC_CACHE_VIPT_ALIASING);
+ int num_colors = dc->sz_k/dc->assoc/TO_KB(PAGE_SIZE);
- if (dc->alias && !handled)
- panic("Enable CONFIG_ARC_CACHE_VIPT_ALIASING\n");
- else if (!dc->alias && handled)
+ if (dc->alias) {
+ if (!handled)
+ panic("Enable CONFIG_ARC_CACHE_VIPT_ALIASING\n");
+ if (CACHE_COLORS_NUM != num_colors)
+ panic("CACHE_COLORS_NUM not optimized for config\n");
+ } else if (!dc->alias && handled) {
panic("Disable CONFIG_ARC_CACHE_VIPT_ALIASING\n");
+ }
}
}