With the MEMBLOCK_PTEMAP flag, force a PTE-level mapping. This also disables contiguous PTEs to make sure any page from the memblock can be safely unmapped from the linear map.
Signed-off-by: Vincent Donnefort vdonnefort@google.com --- arch/arm64/mm/mmu.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-)
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 140520b351e2..a4cafafa1d82 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -1184,9 +1184,8 @@ static void __init map_mem(void) phys_addr_t init_begin = __pa_symbol(__init_begin); phys_addr_t init_end = __pa_symbol(__init_end); phys_addr_t kernel_end = __pa_symbol(__bss_stop); - phys_addr_t start, end; int flags = NO_EXEC_MAPPINGS; - u64 i; + struct memblock_region *r;
/* * Setting hierarchical PXNTable attributes on table entries covering @@ -1226,9 +1225,14 @@ static void __init map_mem(void) flags);
/* map all the memory banks */ - for_each_mem_range(i, &start, &end) { + for_each_mem_region(r) { + phys_addr_t start, end; + int rflags = flags; + + if (memblock_is_nomap(r)) + continue; /* - * for_each_mem_range may return sub-page-aligned boundaries + * for_each_mem_region may return sub-page-aligned boundaries * after memblock_mark_nomap() splits regions at byte precision. * __create_pgd_mapping_locked aligns phys down to PAGE_MASK, * which could accidentally map no-map memory on the boundary. @@ -1237,17 +1241,21 @@ static void __init map_mem(void) * regions. The cost is at most one page of unmapped gap at * each boundary. */ - start = PAGE_ALIGN(start); - end = end & PAGE_MASK; + start = PAGE_ALIGN(r->base); + end = (r->base + r->size) & PAGE_MASK; if (start >= end) continue; + + if (memblock_is_ptemap(r)) + rflags |= NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS; + /* * The linear map must allow allocation tags reading/writing * if MTE is present. Otherwise, it has the same attributes as * PAGE_KERNEL. */ __map_memblock(start, end, pgprot_tagged(PAGE_KERNEL), - flags); + rflags); } }