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: Ying-Chun Liu (PaulLiu) paul.liu@linaro.org Signed-off-by: Pierre-Clément Tosi ptosi@google.com Cc: Tom Rini trini@konsulko.com --- arch/arm/lib/cache.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/arch/arm/lib/cache.c b/arch/arm/lib/cache.c index 1a589c7e2a..7a16015867 100644 --- 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;