From 8d91c1e411f55d7ea91b1183a2e9f8088fb4d5be Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Tue, 15 Dec 2015 14:52:16 -0300 Subject: Linux-libre 4.3.2-gnu --- arch/arm/mm/mmu.c | 92 +++++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 83 insertions(+), 9 deletions(-) (limited to 'arch/arm/mm/mmu.c') diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 870838a46..7cd15143a 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -291,13 +291,13 @@ static struct mem_type mem_types[] = { .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY | L_PTE_RDONLY, .prot_l1 = PMD_TYPE_TABLE, - .domain = DOMAIN_USER, + .domain = DOMAIN_VECTORS, }, [MT_HIGH_VECTORS] = { .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY | L_PTE_USER | L_PTE_RDONLY, .prot_l1 = PMD_TYPE_TABLE, - .domain = DOMAIN_USER, + .domain = DOMAIN_VECTORS, }, [MT_MEMORY_RWX] = { .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY, @@ -357,6 +357,47 @@ const struct mem_type *get_mem_type(unsigned int type) } EXPORT_SYMBOL(get_mem_type); +static pte_t *(*pte_offset_fixmap)(pmd_t *dir, unsigned long addr); + +static pte_t bm_pte[PTRS_PER_PTE + PTE_HWTABLE_PTRS] + __aligned(PTE_HWTABLE_OFF + PTE_HWTABLE_SIZE) __initdata; + +static pte_t * __init pte_offset_early_fixmap(pmd_t *dir, unsigned long addr) +{ + return &bm_pte[pte_index(addr)]; +} + +static pte_t *pte_offset_late_fixmap(pmd_t *dir, unsigned long addr) +{ + return pte_offset_kernel(dir, addr); +} + +static inline pmd_t * __init fixmap_pmd(unsigned long addr) +{ + pgd_t *pgd = pgd_offset_k(addr); + pud_t *pud = pud_offset(pgd, addr); + pmd_t *pmd = pmd_offset(pud, addr); + + return pmd; +} + +void __init early_fixmap_init(void) +{ + pmd_t *pmd; + + /* + * The early fixmap range spans multiple pmds, for which + * we are not prepared: + */ + BUILD_BUG_ON((__fix_to_virt(__end_of_permanent_fixed_addresses) >> PMD_SHIFT) + != FIXADDR_TOP >> PMD_SHIFT); + + pmd = fixmap_pmd(FIXADDR_TOP); + pmd_populate_kernel(&init_mm, pmd, bm_pte); + + pte_offset_fixmap = pte_offset_early_fixmap; +} + /* * To avoid TLB flush broadcasts, this uses local_flush_tlb_kernel_range(). * As a result, this can only be called with preemption disabled, as under @@ -365,7 +406,7 @@ EXPORT_SYMBOL(get_mem_type); void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot) { unsigned long vaddr = __fix_to_virt(idx); - pte_t *pte = pte_offset_kernel(pmd_off_k(vaddr), vaddr); + pte_t *pte = pte_offset_fixmap(pmd_off_k(vaddr), vaddr); /* Make sure fixmap region does not exceed available allocation. */ BUILD_BUG_ON(FIXADDR_START + (__end_of_fixed_addresses * PAGE_SIZE) > @@ -855,7 +896,7 @@ static void __init create_mapping(struct map_desc *md) } if ((md->type == MT_DEVICE || md->type == MT_ROM) && - md->virtual >= PAGE_OFFSET && + md->virtual >= PAGE_OFFSET && md->virtual < FIXADDR_START && (md->virtual < VMALLOC_START || md->virtual >= VMALLOC_END)) { pr_warn("BUG: mapping for 0x%08llx at 0x%08lx out of vmalloc space\n", (long long)__pfn_to_phys((u64)md->pfn), md->virtual); @@ -1219,10 +1260,10 @@ void __init arm_mm_memblock_reserve(void) /* * Set up the device mappings. Since we clear out the page tables for all - * mappings above VMALLOC_START, we will remove any debug device mappings. - * This means you have to be careful how you debug this function, or any - * called function. This means you can't use any function or debugging - * method which may touch any device, otherwise the kernel _will_ crash. + * mappings above VMALLOC_START, except early fixmap, we might remove debug + * device mappings. This means earlycon can be used to debug this function + * Any other function or debugging method which may touch any device _will_ + * crash the kernel. */ static void __init devicemaps_init(const struct machine_desc *mdesc) { @@ -1237,7 +1278,10 @@ static void __init devicemaps_init(const struct machine_desc *mdesc) early_trap_init(vectors); - for (addr = VMALLOC_START; addr; addr += PMD_SIZE) + /* + * Clear page table except top pmd used by early fixmaps + */ + for (addr = VMALLOC_START; addr < (FIXADDR_TOP & PMD_MASK); addr += PMD_SIZE) pmd_clear(pmd_off_k(addr)); /* @@ -1489,6 +1533,35 @@ void __init early_paging_init(const struct machine_desc *mdesc) #endif +static void __init early_fixmap_shutdown(void) +{ + int i; + unsigned long va = fix_to_virt(__end_of_permanent_fixed_addresses - 1); + + pte_offset_fixmap = pte_offset_late_fixmap; + pmd_clear(fixmap_pmd(va)); + local_flush_tlb_kernel_page(va); + + for (i = 0; i < __end_of_permanent_fixed_addresses; i++) { + pte_t *pte; + struct map_desc map; + + map.virtual = fix_to_virt(i); + pte = pte_offset_early_fixmap(pmd_off_k(map.virtual), map.virtual); + + /* Only i/o device mappings are supported ATM */ + if (pte_none(*pte) || + (pte_val(*pte) & L_PTE_MT_MASK) != L_PTE_MT_DEV_SHARED) + continue; + + map.pfn = pte_pfn(*pte); + map.type = MT_DEVICE; + map.length = PAGE_SIZE; + + create_mapping(&map); + } +} + /* * paging_init() sets up the page tables, initialises the zone memory * maps, and sets up the zero page, bad page and bad page tables. @@ -1502,6 +1575,7 @@ void __init paging_init(const struct machine_desc *mdesc) map_lowmem(); memblock_set_current_limit(arm_lowmem_limit); dma_contiguous_remap(); + early_fixmap_shutdown(); devicemaps_init(mdesc); kmap_init(); tcm_init(); -- cgit v1.2.3-54-g00ecf