From 10527e808123f4b12db604993638b368220e7814 Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Tue, 28 Nov 2017 14:04:40 +0530 Subject: [PATCH] powerpc/hash: Skip non initialized page size in init_hpte_page_sizes One of the easiest way to test config with 4K HPTE is to disable 64K hardware page size like below. int __init htab_dt_scan_page_sizes(unsigned long node, size -= 3; prop += 3; base_idx = get_idx_from_shift(base_shift); - if (base_idx < 0) { + if (base_idx < 0 || base_idx == MMU_PAGE_64K) { /* skip the pte encoding also */ prop += lpnum * 2; size -= lpnum * 2; But then this results in error in other part of the code such as MPSS parsing where we look at 4K base page size and 64K actual page size support. This patch fix MPSS parsing by ignoring the actual page sizes marked unsupported. In reality this can happen only with a corrupt device tree. But it is good to tighten the error check. Signed-off-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman --- arch/powerpc/mm/hash_utils_64.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c index 462c34e7b01d2..d97be8d207152 100644 --- a/arch/powerpc/mm/hash_utils_64.c +++ b/arch/powerpc/mm/hash_utils_64.c @@ -608,7 +608,7 @@ static void init_hpte_page_sizes(void) continue; /* not a supported page size */ for (ap = bp; ap < MMU_PAGE_COUNT; ++ap) { penc = mmu_psize_defs[bp].penc[ap]; - if (penc == -1) + if (penc == -1 || !mmu_psize_defs[ap].shift) continue; shift = mmu_psize_defs[ap].shift - LP_SHIFT; if (shift <= 0) -- 2.39.5