From 3de1f52a3ae823265299409e276f56cdadddc310 Mon Sep 17 00:00:00 2001 From: Laura Abbott Date: Thu, 25 Jun 2015 01:04:20 +0100 Subject: ARM: 8394/1: update memblock limit after mapping lowmem The memblock limit is currently used in find_limits to find the bounds for ZONE_NORMAL. The memblock limit may need to be rounded down a PMD size to ensure allocations are fully mapped though. This has the side effect of reducing the amount of memory in ZONE_NORMAL. Once all lowmem is mapped, it's safe to change the memblock limit back to include the unaligned section. Adjust the memblock limit after lowmem mapping is complete. Before: # cat /proc/zoneinfo | grep managed managed 62907 managed 424 After: # cat /proc/zoneinfo | grep managed managed 63331 Signed-off-by: Laura Abbott Reviewed-by: Mark Rutland Tested-by: Mark Rutland Signed-off-by: Russell King --- arch/arm/mm/mmu.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/arm/mm/mmu.c') diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 7186382672b5..904d1532e6d0 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -1519,6 +1519,7 @@ void __init paging_init(const struct machine_desc *mdesc) build_mem_type_table(); prepare_page_table(); map_lowmem(); + memblock_set_current_limit(arm_lowmem_limit); dma_contiguous_remap(); devicemaps_init(mdesc); kmap_init(); -- cgit v1.2.3-70-g09d2 From eeb3fee8f6cca5e7bf1647d9e327c7b40e384578 Mon Sep 17 00:00:00 2001 From: Russell King Date: Thu, 25 Jun 2015 10:52:58 +0100 Subject: ARM: add helpful message when truncating physical memory Add a nmessage to suggest that HIGHMEM is enabled when physical memory is truncated due to lack of virtual address space to map it in the low memory mapping. Signed-off-by: Russell King --- arch/arm/mm/mmu.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'arch/arm/mm/mmu.c') diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 904d1532e6d0..79de062c6077 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -1072,6 +1072,7 @@ void __init sanity_check_meminfo(void) int highmem = 0; phys_addr_t vmalloc_limit = __pa(vmalloc_min - 1) + 1; struct memblock_region *reg; + bool should_use_highmem = false; for_each_memblock(memory, reg) { phys_addr_t block_start = reg->base; @@ -1090,6 +1091,7 @@ void __init sanity_check_meminfo(void) pr_notice("Ignoring RAM at %pa-%pa (!CONFIG_HIGHMEM)\n", &block_start, &block_end); memblock_remove(reg->base, reg->size); + should_use_highmem = true; continue; } @@ -1100,6 +1102,7 @@ void __init sanity_check_meminfo(void) &block_start, &block_end, &vmalloc_limit); memblock_remove(vmalloc_limit, overlap_size); block_end = vmalloc_limit; + should_use_highmem = true; } } @@ -1134,6 +1137,9 @@ void __init sanity_check_meminfo(void) } } + if (should_use_highmem) + pr_notice("Consider using a HIGHMEM enabled kernel.\n"); + high_memory = __va(arm_lowmem_limit - 1) + 1; /* -- cgit v1.2.3-70-g09d2 From a5f4c561b3b19a9bc43a81da6382b0098ebbc1fb Mon Sep 17 00:00:00 2001 From: Stefan Agner Date: Thu, 13 Aug 2015 00:01:52 +0100 Subject: ARM: 8415/1: early fixmap support for earlycon Add early fixmap support, initially to support permanent, fixed mapping support for early console. A temporary, early pte is created which is migrated to a permanent mapping in paging_init. This is also needed since the attributes may change as the memory types are initialized. The 3MiB range of fixmap spans two pte tables, but currently only one pte is created for early fixmap support. Re-add FIX_KMAP_BEGIN to the index calculation in highmem.c since the index for kmap does not start at zero anymore. This reverts 4221e2e6b316 ("ARM: 8031/1: fixmap: remove FIX_KMAP_BEGIN and FIX_KMAP_END") to some extent. Cc: Mark Salter Cc: Kees Cook Cc: Laura Abbott Cc: Arnd Bergmann Cc: Ard Biesheuvel Signed-off-by: Rob Herring Signed-off-by: Stefan Agner Signed-off-by: Russell King --- arch/arm/Kconfig | 3 ++ arch/arm/include/asm/fixmap.h | 15 +++++++- arch/arm/kernel/setup.c | 4 ++ arch/arm/mm/highmem.c | 6 +-- arch/arm/mm/mmu.c | 88 +++++++++++++++++++++++++++++++++++++++---- 5 files changed, 105 insertions(+), 11 deletions(-) (limited to 'arch/arm/mm/mmu.c') diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index a750c1425c3a..1bcda7cb2e04 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -188,6 +188,9 @@ config ARCH_HAS_ILOG2_U64 config ARCH_HAS_BANDGAP bool +config FIX_EARLYCON_MEM + def_bool y if MMU + config GENERIC_HWEIGHT bool default y diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h index 0415eae1df27..58cfe9f1a687 100644 --- a/arch/arm/include/asm/fixmap.h +++ b/arch/arm/include/asm/fixmap.h @@ -6,9 +6,13 @@ #define FIXADDR_TOP (FIXADDR_END - PAGE_SIZE) #include +#include enum fixed_addresses { - FIX_KMAP_BEGIN, + FIX_EARLYCON_MEM_BASE, + __end_of_permanent_fixed_addresses, + + FIX_KMAP_BEGIN = __end_of_permanent_fixed_addresses, FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * NR_CPUS) - 1, /* Support writing RO kernel text via kprobes, jump labels, etc. */ @@ -18,7 +22,16 @@ enum fixed_addresses { __end_of_fixed_addresses }; +#define FIXMAP_PAGE_COMMON (L_PTE_YOUNG | L_PTE_PRESENT | L_PTE_XN | L_PTE_DIRTY) + +#define FIXMAP_PAGE_NORMAL (FIXMAP_PAGE_COMMON | L_PTE_MT_WRITEBACK) + +/* Used by set_fixmap_(io|nocache), both meant for mapping a device */ +#define FIXMAP_PAGE_IO (FIXMAP_PAGE_COMMON | L_PTE_MT_DEV_SHARED | L_PTE_SHARED) +#define FIXMAP_PAGE_NOCACHE FIXMAP_PAGE_IO + void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot); +void __init early_fixmap_init(void); #include diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index 6bbec6042052..e2ecee6b70ca 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -37,6 +37,7 @@ #include #include #include +#include #include #include #include @@ -954,6 +955,9 @@ void __init setup_arch(char **cmdline_p) strlcpy(cmd_line, boot_command_line, COMMAND_LINE_SIZE); *cmdline_p = cmd_line; + if (IS_ENABLED(CONFIG_FIX_EARLYCON_MEM)) + early_fixmap_init(); + parse_early_param(); #ifdef CONFIG_MMU diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c index ee8dfa793989..9df5f09585ca 100644 --- a/arch/arm/mm/highmem.c +++ b/arch/arm/mm/highmem.c @@ -79,7 +79,7 @@ void *kmap_atomic(struct page *page) type = kmap_atomic_idx_push(); - idx = type + KM_TYPE_NR * smp_processor_id(); + idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id(); vaddr = __fix_to_virt(idx); #ifdef CONFIG_DEBUG_HIGHMEM /* @@ -106,7 +106,7 @@ void __kunmap_atomic(void *kvaddr) if (kvaddr >= (void *)FIXADDR_START) { type = kmap_atomic_idx(); - idx = type + KM_TYPE_NR * smp_processor_id(); + idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id(); if (cache_is_vivt()) __cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE); @@ -138,7 +138,7 @@ void *kmap_atomic_pfn(unsigned long pfn) return page_address(page); type = kmap_atomic_idx_push(); - idx = type + KM_TYPE_NR * smp_processor_id(); + idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id(); vaddr = __fix_to_virt(idx); #ifdef CONFIG_DEBUG_HIGHMEM BUG_ON(!pte_none(get_fixmap_pte(vaddr))); diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 6ca7d9aa896f..fb9e817d08bb 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -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); @@ -1213,10 +1254,10 @@ 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) { @@ -1231,7 +1272,10 @@ 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)); /* @@ -1483,6 +1527,35 @@ 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. @@ -1495,6 +1568,7 @@ void __init paging_init(const struct machine_desc *mdesc) prepare_page_table(); map_lowmem(); dma_contiguous_remap(); + early_fixmap_shutdown(); devicemaps_init(mdesc); kmap_init(); tcm_init(); -- cgit v1.2.3-70-g09d2 From a02d8dfd54cdf3b1b0464ccc2c1c4afe2c003a35 Mon Sep 17 00:00:00 2001 From: Russell King Date: Fri, 21 Aug 2015 09:38:31 +0100 Subject: ARM: domains: keep vectors in separate domain Keep the machine vectors in its own domain to avoid software based user access control from making the vector code inaccessible, and thereby deadlocking the machine. Signed-off-by: Russell King --- arch/arm/include/asm/domain.h | 4 +++- arch/arm/include/asm/pgtable-2level-hwdef.h | 1 + arch/arm/mm/mmu.c | 4 ++-- arch/arm/mm/pgd.c | 10 ++++++++++ 4 files changed, 16 insertions(+), 3 deletions(-) (limited to 'arch/arm/mm/mmu.c') diff --git a/arch/arm/include/asm/domain.h b/arch/arm/include/asm/domain.h index 08b601e69ddc..396a12e486fe 100644 --- a/arch/arm/include/asm/domain.h +++ b/arch/arm/include/asm/domain.h @@ -43,6 +43,7 @@ #define DOMAIN_USER 1 #define DOMAIN_IO 0 #endif +#define DOMAIN_VECTORS 3 /* * Domain types @@ -62,7 +63,8 @@ (domain_val(DOMAIN_USER, DOMAIN_CLIENT) | \ domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \ domain_val(DOMAIN_TABLE, DOMAIN_MANAGER) | \ - domain_val(DOMAIN_IO, DOMAIN_CLIENT)) + domain_val(DOMAIN_IO, DOMAIN_CLIENT) | \ + domain_val(DOMAIN_VECTORS, DOMAIN_CLIENT)) #ifndef __ASSEMBLY__ diff --git a/arch/arm/include/asm/pgtable-2level-hwdef.h b/arch/arm/include/asm/pgtable-2level-hwdef.h index 5e68278e953e..d0131ee6f6af 100644 --- a/arch/arm/include/asm/pgtable-2level-hwdef.h +++ b/arch/arm/include/asm/pgtable-2level-hwdef.h @@ -23,6 +23,7 @@ #define PMD_PXNTABLE (_AT(pmdval_t, 1) << 2) /* v7 */ #define PMD_BIT4 (_AT(pmdval_t, 1) << 4) #define PMD_DOMAIN(x) (_AT(pmdval_t, (x)) << 5) +#define PMD_DOMAIN_MASK PMD_DOMAIN(0x0f) #define PMD_PROTECTION (_AT(pmdval_t, 1) << 9) /* v5 */ /* * - section diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 6ca7d9aa896f..a016de248034 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, diff --git a/arch/arm/mm/pgd.c b/arch/arm/mm/pgd.c index a3681f11dd9f..e683db1b90a3 100644 --- a/arch/arm/mm/pgd.c +++ b/arch/arm/mm/pgd.c @@ -84,6 +84,16 @@ pgd_t *pgd_alloc(struct mm_struct *mm) if (!new_pte) goto no_pte; +#ifndef CONFIG_ARM_LPAE + /* + * Modify the PTE pointer to have the correct domain. This + * needs to be the vectors domain to avoid the low vectors + * being unmapped. + */ + pmd_val(*new_pmd) &= ~PMD_DOMAIN_MASK; + pmd_val(*new_pmd) |= PMD_DOMAIN(DOMAIN_VECTORS); +#endif + init_pud = pud_offset(init_pgd, 0); init_pmd = pmd_offset(init_pud, 0); init_pte = pte_offset_map(init_pmd, 0); -- cgit v1.2.3-70-g09d2