arm64: Initialize TLB memory if CMO_BY_VA_ONLY

Memory used to hold the page tables is allocated from the top of RAM
with no prior initialization and could therefore hold invalid data. As
invalidate_dcache_all() will be called before the MMU has been
initialized and as that function relies indirectly on the page tables
when using CMO_BY_VA_ONLY, these must be in a valid state from their
allocation.

Signed-off-by: Pierre-Clément Tosi <ptosi@google.com>
[ Paul: pick from the Android tree. Fix checkpatch warnings, and rebased
  to the upstream. ]
Signed-off-by: Ying-Chun Liu (PaulLiu) <paul.liu@linaro.org>
Cc: Tom Rini <trini@konsulko.com>
Link: https://android.googlesource.com/platform/external/u-boot/+/e3ceef4230b772186c6853cace4a676a407e6ab7

diff --git a/arch/arm/lib/cache.c b/arch/arm/lib/cache.c
index 1a589c7e2a0da419d4ceadc5b9442246d583d0ea..7a160158671195df67d708274945d02063c0806b 100644 (file)
--- a/arch/arm/lib/cache.c
+++ b/arch/arm/lib/cache.c
@@ -159,6 +159,15 @@ __weak int arm_reserve_mmu(void)
         */
        gd->arch.tlb_allocated = gd->arch.tlb_addr;
 #endif
+
+       if (IS_ENABLED(CONFIG_CMO_BY_VA_ONLY)) {
+               /*
+                * As invalidate_dcache_all() will be called before
+                * mmu_setup(), we should make sure that the PTs are
+                * already in a valid state.
+                */
+               memset((void *)gd->arch.tlb_addr, 0, gd->arch.tlb_size);
+       }
 #endif
 
        return 0;