| /* |
| * linux/arch/arm/mm/nommu.c |
| * |
| * ARM uCLinux supporting functions. |
| */ |
| #include <linux/module.h> |
| #include <linux/mm.h> |
| #include <linux/pagemap.h> |
| #include <linux/io.h> |
| #include <linux/memblock.h> |
| #include <linux/kernel.h> |
| |
| #include <asm/cacheflush.h> |
| #include <asm/sections.h> |
| #include <asm/page.h> |
| #include <asm/setup.h> |
| #include <asm/traps.h> |
| #include <asm/mach/arch.h> |
| #include <asm/cputype.h> |
| #include <asm/mpu.h> |
| #include <asm/procinfo.h> |
| |
| #include "mm.h" |
| |
| #ifdef CONFIG_ARM_MPU |
| struct mpu_rgn_info mpu_rgn_info; |
| |
| /* Region number */ |
| static void rgnr_write(u32 v) |
| { |
| asm("mcr p15, 0, %0, c6, c2, 0" : : "r" (v)); |
| } |
| |
| /* Data-side / unified region attributes */ |
| |
| /* Region access control register */ |
| static void dracr_write(u32 v) |
| { |
| asm("mcr p15, 0, %0, c6, c1, 4" : : "r" (v)); |
| } |
| |
| /* Region size register */ |
| static void drsr_write(u32 v) |
| { |
| asm("mcr p15, 0, %0, c6, c1, 2" : : "r" (v)); |
| } |
| |
| /* Region base address register */ |
| static void drbar_write(u32 v) |
| { |
| asm("mcr p15, 0, %0, c6, c1, 0" : : "r" (v)); |
| } |
| |
| static u32 drbar_read(void) |
| { |
| u32 v; |
| asm("mrc p15, 0, %0, c6, c1, 0" : "=r" (v)); |
| return v; |
| } |
| /* Optional instruction-side region attributes */ |
| |
| /* I-side Region access control register */ |
| static void iracr_write(u32 v) |
| { |
| asm("mcr p15, 0, %0, c6, c1, 5" : : "r" (v)); |
| } |
| |
| /* I-side Region size register */ |
| static void irsr_write(u32 v) |
| { |
| asm("mcr p15, 0, %0, c6, c1, 3" : : "r" (v)); |
| } |
| |
| /* I-side Region base address register */ |
| static void irbar_write(u32 v) |
| { |
| asm("mcr p15, 0, %0, c6, c1, 1" : : "r" (v)); |
| } |
| |
| static unsigned long irbar_read(void) |
| { |
| unsigned long v; |
| asm("mrc p15, 0, %0, c6, c1, 1" : "=r" (v)); |
| return v; |
| } |
| |
| /* MPU initialisation functions */ |
| void __init sanity_check_meminfo_mpu(void) |
| { |
| int i; |
| phys_addr_t phys_offset = PHYS_OFFSET; |
| phys_addr_t aligned_region_size, specified_mem_size, rounded_mem_size; |
| struct memblock_region *reg; |
| bool first = true; |
| phys_addr_t mem_start; |
| phys_addr_t mem_end; |
| |
| for_each_memblock(memory, reg) { |
| if (first) { |
| /* |
| * Initially only use memory continuous from |
| * PHYS_OFFSET */ |
| if (reg->base != phys_offset) |
| panic("First memory bank must be contiguous from PHYS_OFFSET"); |
| |
| mem_start = reg->base; |
| mem_end = reg->base + reg->size; |
| specified_mem_size = reg->size; |
| first = false; |
| } else { |
| /* |
| * memblock auto merges contiguous blocks, remove |
| * all blocks afterwards |
| */ |
| pr_notice("Ignoring RAM after %pa, memory at %pa ignored\n", |
| &mem_start, ®->base); |
| memblock_remove(reg->base, reg->size); |
| } |
| } |
| |
| /* |
| * MPU has curious alignment requirements: Size must be power of 2, and |
| * region start must be aligned to the region size |
| */ |
| if (phys_offset != 0) |
| pr_info("PHYS_OFFSET != 0 => MPU Region size constrained by alignment requirements\n"); |
| |
| /* |
| * Maximum aligned region might overflow phys_addr_t if phys_offset is |
| * 0. Hence we keep everything below 4G until we take the smaller of |
| * the aligned_region_size and rounded_mem_size, one of which is |
| * guaranteed to be smaller than the maximum physical address. |
| */ |
| aligned_region_size = (phys_offset - 1) ^ (phys_offset); |
| /* Find the max power-of-two sized region that fits inside our bank */ |
| rounded_mem_size = (1 << __fls(specified_mem_size)) - 1; |
| |
| /* The actual region size is the smaller of the two */ |
| aligned_region_size = aligned_region_size < rounded_mem_size |
| ? aligned_region_size + 1 |
| : rounded_mem_size + 1; |
| |
| if (aligned_region_size != specified_mem_size) { |
| pr_warn("Truncating memory from %pa to %pa (MPU region constraints)", |
| &specified_mem_size, &aligned_region_size); |
| memblock_remove(mem_start + aligned_region_size, |
| specified_mem_size - aligned_round_size); |
| |
| mem_end = mem_start + aligned_region_size; |
| } |
| |
| pr_debug("MPU Region from %pa size %pa (end %pa))\n", |
| &phys_offset, &aligned_region_size, &mem_end); |
| |
| } |
| |
| static int mpu_present(void) |
| { |
| return ((read_cpuid_ext(CPUID_EXT_MMFR0) & MMFR0_PMSA) == MMFR0_PMSAv7); |
| } |
| |
| static int mpu_max_regions(void) |
| { |
| /* |
| * We don't support a different number of I/D side regions so if we |
| * have separate instruction and data memory maps then return |
| * whichever side has a smaller number of supported regions. |
| */ |
| u32 dregions, iregions, mpuir; |
| mpuir = read_cpuid(CPUID_MPUIR); |
| |
| dregions = iregions = (mpuir & MPUIR_DREGION_SZMASK) >> MPUIR_DREGION; |
| |
| /* Check for separate d-side and i-side memory maps */ |
| if (mpuir & MPUIR_nU) |
| iregions = (mpuir & MPUIR_IREGION_SZMASK) >> MPUIR_IREGION; |
| |
| /* Use the smallest of the two maxima */ |
| return min(dregions, iregions); |
| } |
| |
| static int mpu_iside_independent(void) |
| { |
| /* MPUIR.nU specifies whether there is *not* a unified memory map */ |
| return read_cpuid(CPUID_MPUIR) & MPUIR_nU; |
| } |
| |
| static int mpu_min_region_order(void) |
| { |
| u32 drbar_result, irbar_result; |
| /* We've kept a region free for this probing */ |
| rgnr_write(MPU_PROBE_REGION); |
| isb(); |
| /* |
| * As per ARM ARM, write 0xFFFFFFFC to DRBAR to find the minimum |
| * region order |
| */ |
| drbar_write(0xFFFFFFFC); |
| drbar_result = irbar_result = drbar_read(); |
| drbar_write(0x0); |
| /* If the MPU is non-unified, we use the larger of the two minima*/ |
| if (mpu_iside_independent()) { |
| irbar_write(0xFFFFFFFC); |
| irbar_result = irbar_read(); |
| irbar_write(0x0); |
| } |
| isb(); /* Ensure that MPU region operations have completed */ |
| /* Return whichever result is larger */ |
| return __ffs(max(drbar_result, irbar_result)); |
| } |
| |
| static int mpu_setup_region(unsigned int number, phys_addr_t start, |
| unsigned int size_order, unsigned int properties) |
| { |
| u32 size_data; |
| |
| /* We kept a region free for probing resolution of MPU regions*/ |
| if (number > mpu_max_regions() || number == MPU_PROBE_REGION) |
| return -ENOENT; |
| |
| if (size_order > 32) |
| return -ENOMEM; |
| |
| if (size_order < mpu_min_region_order()) |
| return -ENOMEM; |
| |
| /* Writing N to bits 5:1 (RSR_SZ) specifies region size 2^N+1 */ |
| size_data = ((size_order - 1) << MPU_RSR_SZ) | 1 << MPU_RSR_EN; |
| |
| dsb(); /* Ensure all previous data accesses occur with old mappings */ |
| rgnr_write(number); |
| isb(); |
| drbar_write(start); |
| dracr_write(properties); |
| isb(); /* Propagate properties before enabling region */ |
| drsr_write(size_data); |
| |
| /* Check for independent I-side registers */ |
| if (mpu_iside_independent()) { |
| irbar_write(start); |
| iracr_write(properties); |
| isb(); |
| irsr_write(size_data); |
| } |
| isb(); |
| |
| /* Store region info (we treat i/d side the same, so only store d) */ |
| mpu_rgn_info.rgns[number].dracr = properties; |
| mpu_rgn_info.rgns[number].drbar = start; |
| mpu_rgn_info.rgns[number].drsr = size_data; |
| return 0; |
| } |
| |
| /* |
| * Set up default MPU regions, doing nothing if there is no MPU |
| */ |
| void __init mpu_setup(void) |
| { |
| int region_err; |
| if (!mpu_present()) |
| return; |
| |
| region_err = mpu_setup_region(MPU_RAM_REGION, PHYS_OFFSET, |
| ilog2(meminfo.bank[0].size), |
| MPU_AP_PL1RW_PL0RW | MPU_RGN_NORMAL); |
| if (region_err) { |
| panic("MPU region initialization failure! %d", region_err); |
| } else { |
| pr_info("Using ARMv7 PMSA Compliant MPU. " |
| "Region independence: %s, Max regions: %d\n", |
| mpu_iside_independent() ? "Yes" : "No", |
| mpu_max_regions()); |
| } |
| } |
| #else |
| static void sanity_check_meminfo_mpu(void) {} |
| static void __init mpu_setup(void) {} |
| #endif /* CONFIG_ARM_MPU */ |
| |
| void __init arm_mm_memblock_reserve(void) |
| { |
| #ifndef CONFIG_CPU_V7M |
| /* |
| * Register the exception vector page. |
| * some architectures which the DRAM is the exception vector to trap, |
| * alloc_page breaks with error, although it is not NULL, but "0." |
| */ |
| memblock_reserve(CONFIG_VECTORS_BASE, PAGE_SIZE); |
| #else /* ifndef CONFIG_CPU_V7M */ |
| /* |
| * There is no dedicated vector page on V7-M. So nothing needs to be |
| * reserved here. |
| */ |
| #endif |
| } |
| |
| void __init sanity_check_meminfo(void) |
| { |
| phys_addr_t end; |
| sanity_check_meminfo_mpu(); |
| end = memblock_end_of_DRAM(); |
| high_memory = __va(end - 1) + 1; |
| } |
| |
| /* |
| * early_paging_init() recreates boot time page table setup, allowing machines |
| * to switch over to a high (>4G) address space on LPAE systems |
| */ |
| void __init early_paging_init(const struct machine_desc *mdesc, |
| struct proc_info_list *procinfo) |
| { |
| } |
| |
| /* |
| * paging_init() sets up the page tables, initialises the zone memory |
| * maps, and sets up the zero page, bad page and bad page tables. |
| */ |
| void __init paging_init(const struct machine_desc *mdesc) |
| { |
| early_trap_init((void *)CONFIG_VECTORS_BASE); |
| mpu_setup(); |
| bootmem_init(); |
| } |
| |
| /* |
| * We don't need to do anything here for nommu machines. |
| */ |
| void setup_mm_for_reboot(void) |
| { |
| } |
| |
| void flush_dcache_page(struct page *page) |
| { |
| __cpuc_flush_dcache_area(page_address(page), PAGE_SIZE); |
| } |
| EXPORT_SYMBOL(flush_dcache_page); |
| |
| void flush_kernel_dcache_page(struct page *page) |
| { |
| __cpuc_flush_dcache_area(page_address(page), PAGE_SIZE); |
| } |
| EXPORT_SYMBOL(flush_kernel_dcache_page); |
| |
| void copy_to_user_page(struct vm_area_struct *vma, struct page *page, |
| unsigned long uaddr, void *dst, const void *src, |
| unsigned long len) |
| { |
| memcpy(dst, src, len); |
| if (vma->vm_flags & VM_EXEC) |
| __cpuc_coherent_user_range(uaddr, uaddr + len); |
| } |
| |
| void __iomem *__arm_ioremap_pfn(unsigned long pfn, unsigned long offset, |
| size_t size, unsigned int mtype) |
| { |
| if (pfn >= (0x100000000ULL >> PAGE_SHIFT)) |
| return NULL; |
| return (void __iomem *) (offset + (pfn << PAGE_SHIFT)); |
| } |
| EXPORT_SYMBOL(__arm_ioremap_pfn); |
| |
| void __iomem *__arm_ioremap_pfn_caller(unsigned long pfn, unsigned long offset, |
| size_t size, unsigned int mtype, void *caller) |
| { |
| return __arm_ioremap_pfn(pfn, offset, size, mtype); |
| } |
| |
| void __iomem *__arm_ioremap(phys_addr_t phys_addr, size_t size, |
| unsigned int mtype) |
| { |
| return (void __iomem *)phys_addr; |
| } |
| EXPORT_SYMBOL(__arm_ioremap); |
| |
| void __iomem * (*arch_ioremap_caller)(phys_addr_t, size_t, unsigned int, void *); |
| |
| void __iomem *__arm_ioremap_caller(phys_addr_t phys_addr, size_t size, |
| unsigned int mtype, void *caller) |
| { |
| return __arm_ioremap(phys_addr, size, mtype); |
| } |
| |
| void (*arch_iounmap)(volatile void __iomem *); |
| |
| void __arm_iounmap(volatile void __iomem *addr) |
| { |
| } |
| EXPORT_SYMBOL(__arm_iounmap); |