From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: AndrĂ© Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- arch/arm/mm/nommu.c | 389 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 389 insertions(+) create mode 100644 arch/arm/mm/nommu.c (limited to 'arch/arm/mm/nommu.c') diff --git a/arch/arm/mm/nommu.c b/arch/arm/mm/nommu.c new file mode 100644 index 000000000..a014dfacd --- /dev/null +++ b/arch/arm/mm/nommu.c @@ -0,0 +1,389 @@ +/* + * linux/arch/arm/mm/nommu.c + * + * ARM uCLinux supporting functions. + */ +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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; + memblock_set_current_limit(end); +} + +/* + * 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); -- cgit v1.2.3-54-g00ecf