diff options
Diffstat (limited to 'arch/nds32/mm/init.c')
| -rw-r--r-- | arch/nds32/mm/init.c | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/arch/nds32/mm/init.c b/arch/nds32/mm/init.c new file mode 100644 index 000000000..fa86f7b2f --- /dev/null +++ b/arch/nds32/mm/init.c @@ -0,0 +1,264 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 1995-2005 Russell King +// Copyright (C) 2012 ARM Ltd. +// Copyright (C) 2013-2017 Andes Technology Corporation + +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/swap.h> +#include <linux/init.h> +#include <linux/memblock.h> +#include <linux/mman.h> +#include <linux/nodemask.h> +#include <linux/initrd.h> +#include <linux/highmem.h> + +#include <asm/sections.h> +#include <asm/setup.h> +#include <asm/tlb.h> +#include <asm/page.h> + +DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); +DEFINE_SPINLOCK(anon_alias_lock); +extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; + +/* + * empty_zero_page is a special page that is used for + * zero-initialized data and COW. + */ +struct page *empty_zero_page; +EXPORT_SYMBOL(empty_zero_page); + +static void __init zone_sizes_init(void) +{ + unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 }; + + max_zone_pfn[ZONE_NORMAL] = max_low_pfn; +#ifdef CONFIG_HIGHMEM + max_zone_pfn[ZONE_HIGHMEM] = max_pfn; +#endif + free_area_init(max_zone_pfn); + +} + +/* + * Map all physical memory under high_memory into kernel's address space. + * + * This is explicitly coded for two-level page tables, so if you need + * something else then this needs to change. + */ +static void __init map_ram(void) +{ + unsigned long v, p, e; + pgd_t *pge; + p4d_t *p4e; + pud_t *pue; + pmd_t *pme; + pte_t *pte; + /* These mark extents of read-only kernel pages... + * ...from vmlinux.lds.S + */ + + p = (u32) memblock_start_of_DRAM() & PAGE_MASK; + e = min((u32) memblock_end_of_DRAM(), (u32) __pa(high_memory)); + + v = (u32) __va(p); + pge = pgd_offset_k(v); + + while (p < e) { + int j; + p4e = p4d_offset(pge, v); + pue = pud_offset(p4e, v); + pme = pmd_offset(pue, v); + + if ((u32) pue != (u32) pge || (u32) pme != (u32) pge) { + panic("%s: Kernel hardcoded for " + "two-level page tables", __func__); + } + + /* Alloc one page for holding PTE's... */ + pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE); + if (!pte) + panic("%s: Failed to allocate %lu bytes align=0x%lx\n", + __func__, PAGE_SIZE, PAGE_SIZE); + set_pmd(pme, __pmd(__pa(pte) + _PAGE_KERNEL_TABLE)); + + /* Fill the newly allocated page with PTE'S */ + for (j = 0; p < e && j < PTRS_PER_PTE; + v += PAGE_SIZE, p += PAGE_SIZE, j++, pte++) { + /* Create mapping between p and v. */ + /* TODO: more fine grant for page access permission */ + set_pte(pte, __pte(p + pgprot_val(PAGE_KERNEL))); + } + + pge++; + } +} +static pmd_t *fixmap_pmd_p; +static void __init fixedrange_init(void) +{ + unsigned long vaddr; + pmd_t *pmd; +#ifdef CONFIG_HIGHMEM + pte_t *pte; +#endif /* CONFIG_HIGHMEM */ + + /* + * Fixed mappings: + */ + vaddr = __fix_to_virt(__end_of_fixed_addresses - 1); + pmd = pmd_off_k(vaddr); + fixmap_pmd_p = memblock_alloc(PAGE_SIZE, PAGE_SIZE); + if (!fixmap_pmd_p) + panic("%s: Failed to allocate %lu bytes align=0x%lx\n", + __func__, PAGE_SIZE, PAGE_SIZE); + set_pmd(pmd, __pmd(__pa(fixmap_pmd_p) + _PAGE_KERNEL_TABLE)); + +#ifdef CONFIG_HIGHMEM + /* + * Permanent kmaps: + */ + vaddr = PKMAP_BASE; + + pmd = pmd_off_k(vaddr); + pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE); + if (!pte) + panic("%s: Failed to allocate %lu bytes align=0x%lx\n", + __func__, PAGE_SIZE, PAGE_SIZE); + set_pmd(pmd, __pmd(__pa(pte) + _PAGE_KERNEL_TABLE)); + pkmap_page_table = pte; +#endif /* CONFIG_HIGHMEM */ +} + +/* + * 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(void) +{ + int i; + void *zero_page; + + pr_info("Setting up paging and PTEs.\n"); + /* clear out the init_mm.pgd that will contain the kernel's mappings */ + for (i = 0; i < PTRS_PER_PGD; i++) + swapper_pg_dir[i] = __pgd(1); + + map_ram(); + + fixedrange_init(); + + /* allocate space for empty_zero_page */ + zero_page = memblock_alloc(PAGE_SIZE, PAGE_SIZE); + if (!zero_page) + panic("%s: Failed to allocate %lu bytes align=0x%lx\n", + __func__, PAGE_SIZE, PAGE_SIZE); + zone_sizes_init(); + + empty_zero_page = virt_to_page(zero_page); + flush_dcache_page(empty_zero_page); +} + +static inline void __init free_highmem(void) +{ +#ifdef CONFIG_HIGHMEM + unsigned long pfn; + for (pfn = PFN_UP(__pa(high_memory)); pfn < max_pfn; pfn++) { + phys_addr_t paddr = (phys_addr_t) pfn << PAGE_SHIFT; + if (!memblock_is_reserved(paddr)) + free_highmem_page(pfn_to_page(pfn)); + } +#endif +} + +static void __init set_max_mapnr_init(void) +{ + max_mapnr = max_pfn; +} + +/* + * mem_init() marks the free areas in the mem_map and tells us how much + * memory is free. This is done after various parts of the system have + * claimed their memory after the kernel image. + */ +void __init mem_init(void) +{ + phys_addr_t memory_start = memblock_start_of_DRAM(); + BUG_ON(!mem_map); + set_max_mapnr_init(); + + free_highmem(); + + /* this will put all low memory onto the freelists */ + memblock_free_all(); + mem_init_print_info(NULL); + + pr_info("virtual kernel memory layout:\n" + " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n" +#ifdef CONFIG_HIGHMEM + " pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n" +#endif + " consist : 0x%08lx - 0x%08lx (%4ld MB)\n" + " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n" + " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n" + " .init : 0x%08lx - 0x%08lx (%4ld kB)\n" + " .data : 0x%08lx - 0x%08lx (%4ld kB)\n" + " .text : 0x%08lx - 0x%08lx (%4ld kB)\n", + FIXADDR_START, FIXADDR_TOP, (FIXADDR_TOP - FIXADDR_START) >> 10, +#ifdef CONFIG_HIGHMEM + PKMAP_BASE, PKMAP_BASE + LAST_PKMAP * PAGE_SIZE, + (LAST_PKMAP * PAGE_SIZE) >> 10, +#endif + CONSISTENT_BASE, CONSISTENT_END, + ((CONSISTENT_END) - (CONSISTENT_BASE)) >> 20, VMALLOC_START, + (unsigned long)VMALLOC_END, (VMALLOC_END - VMALLOC_START) >> 20, + (unsigned long)__va(memory_start), (unsigned long)high_memory, + ((unsigned long)high_memory - + (unsigned long)__va(memory_start)) >> 20, + (unsigned long)&__init_begin, (unsigned long)&__init_end, + ((unsigned long)&__init_end - + (unsigned long)&__init_begin) >> 10, (unsigned long)&_etext, + (unsigned long)&_edata, + ((unsigned long)&_edata - (unsigned long)&_etext) >> 10, + (unsigned long)&_text, (unsigned long)&_etext, + ((unsigned long)&_etext - (unsigned long)&_text) >> 10); + + /* + * Check boundaries twice: Some fundamental inconsistencies can + * be detected at build time already. + */ +#ifdef CONFIG_HIGHMEM + BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > FIXADDR_START); + BUILD_BUG_ON((CONSISTENT_END) > PKMAP_BASE); +#endif + BUILD_BUG_ON(VMALLOC_END > CONSISTENT_BASE); + BUILD_BUG_ON(VMALLOC_START >= VMALLOC_END); + +#ifdef CONFIG_HIGHMEM + BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > FIXADDR_START); + BUG_ON(CONSISTENT_END > PKMAP_BASE); +#endif + BUG_ON(VMALLOC_END > CONSISTENT_BASE); + BUG_ON(VMALLOC_START >= VMALLOC_END); + BUG_ON((unsigned long)high_memory > VMALLOC_START); + + return; +} + +void __set_fixmap(enum fixed_addresses idx, + phys_addr_t phys, pgprot_t flags) +{ + unsigned long addr = __fix_to_virt(idx); + pte_t *pte; + + BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses); + + pte = (pte_t *)&fixmap_pmd_p[pte_index(addr)]; + + if (pgprot_val(flags)) { + set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags)); + } else { + pte_clear(&init_mm, addr, pte); + flush_tlb_kernel_range(addr, addr + PAGE_SIZE); + } +} |