diff options
Diffstat (limited to 'arch/openrisc/mm/init.c')
| -rw-r--r-- | arch/openrisc/mm/init.c | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/arch/openrisc/mm/init.c b/arch/openrisc/mm/init.c new file mode 100644 index 000000000..7f9465231 --- /dev/null +++ b/arch/openrisc/mm/init.c @@ -0,0 +1,235 @@ +/* + * OpenRISC idle.c + * + * Linux architectural port borrowing liberally from similar works of + * others. All original copyrights apply as per the original source + * declaration. + * + * Modifications for the OpenRISC architecture: + * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com> + * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <linux/signal.h> +#include <linux/sched.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/string.h> +#include <linux/types.h> +#include <linux/ptrace.h> +#include <linux/mman.h> +#include <linux/mm.h> +#include <linux/swap.h> +#include <linux/smp.h> +#include <linux/bootmem.h> +#include <linux/init.h> +#include <linux/delay.h> +#include <linux/blkdev.h> /* for initrd_* */ +#include <linux/pagemap.h> +#include <linux/memblock.h> + +#include <asm/segment.h> +#include <asm/pgalloc.h> +#include <asm/pgtable.h> +#include <asm/dma.h> +#include <asm/io.h> +#include <asm/tlb.h> +#include <asm/mmu_context.h> +#include <asm/kmap_types.h> +#include <asm/fixmap.h> +#include <asm/tlbflush.h> +#include <asm/sections.h> + +int mem_init_done; + +DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); + +static void __init zone_sizes_init(void) +{ + unsigned long zones_size[MAX_NR_ZONES]; + + /* Clear the zone sizes */ + memset(zones_size, 0, sizeof(zones_size)); + + /* + * We use only ZONE_NORMAL + */ + zones_size[ZONE_NORMAL] = max_low_pfn; + + free_area_init(zones_size); +} + +extern const char _s_kernel_ro[], _e_kernel_ro[]; + +/* + * Map all physical 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; + pgprot_t prot; + pgd_t *pge; + pud_t *pue; + pmd_t *pme; + pte_t *pte; + /* These mark extents of read-only kernel pages... + * ...from vmlinux.lds.S + */ + struct memblock_region *region; + + v = PAGE_OFFSET; + + for_each_memblock(memory, region) { + p = (u32) region->base & PAGE_MASK; + e = p + (u32) region->size; + + v = (u32) __va(p); + pge = pgd_offset_k(v); + + while (p < e) { + int j; + pue = pud_offset(pge, v); + pme = pmd_offset(pue, v); + + if ((u32) pue != (u32) pge || (u32) pme != (u32) pge) { + panic("%s: OR1K kernel hardcoded for " + "two-level page tables", + __func__); + } + + /* Alloc one page for holding PTE's... */ + pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE); + set_pmd(pme, __pmd(_KERNPG_TABLE + __pa(pte))); + + /* Fill the newly allocated page with PTE'S */ + for (j = 0; p < e && j < PTRS_PER_PGD; + v += PAGE_SIZE, p += PAGE_SIZE, j++, pte++) { + if (v >= (u32) _e_kernel_ro || + v < (u32) _s_kernel_ro) + prot = PAGE_KERNEL; + else + prot = PAGE_KERNEL_RO; + + set_pte(pte, mk_pte_phys(p, prot)); + } + + pge++; + } + + printk(KERN_INFO "%s: Memory: 0x%x-0x%x\n", __func__, + region->base, region->base + region->size); + } +} + +void __init paging_init(void) +{ + extern void tlb_init(void); + + unsigned long end; + int i; + + printk(KERN_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(0); + + /* make sure the current pgd table points to something sane + * (even if it is most probably not used until the next + * switch_mm) + */ + current_pgd = init_mm.pgd; + + end = (unsigned long)__va(max_low_pfn * PAGE_SIZE); + + map_ram(); + + zone_sizes_init(); + + /* self modifying code ;) */ + /* Since the old TLB miss handler has been running up until now, + * the kernel pages are still all RW, so we can still modify the + * text directly... after this change and a TLB flush, the kernel + * pages will become RO. + */ + { + extern unsigned long dtlb_miss_handler; + extern unsigned long itlb_miss_handler; + + unsigned long *dtlb_vector = __va(0x900); + unsigned long *itlb_vector = __va(0xa00); + + printk(KERN_INFO "itlb_miss_handler %p\n", &itlb_miss_handler); + *itlb_vector = ((unsigned long)&itlb_miss_handler - + (unsigned long)itlb_vector) >> 2; + + /* Soft ordering constraint to ensure that dtlb_vector is + * the last thing updated + */ + barrier(); + + printk(KERN_INFO "dtlb_miss_handler %p\n", &dtlb_miss_handler); + *dtlb_vector = ((unsigned long)&dtlb_miss_handler - + (unsigned long)dtlb_vector) >> 2; + + } + + /* Soft ordering constraint to ensure that cache invalidation and + * TLB flush really happen _after_ code has been modified. + */ + barrier(); + + /* Invalidate instruction caches after code modification */ + mtspr(SPR_ICBIR, 0x900); + mtspr(SPR_ICBIR, 0xa00); + + /* New TLB miss handlers and kernel page tables are in now place. + * Make sure that page flags get updated for all pages in TLB by + * flushing the TLB and forcing all TLB entries to be recreated + * from their page table flags. + */ + flush_tlb_all(); +} + +/* References to section boundaries */ + +void __init mem_init(void) +{ + BUG_ON(!mem_map); + + max_mapnr = max_low_pfn; + high_memory = (void *)__va(max_low_pfn * PAGE_SIZE); + + /* clear the zero-page */ + memset((void *)empty_zero_page, 0, PAGE_SIZE); + + /* this will put all low memory onto the freelists */ + free_all_bootmem(); + + mem_init_print_info(NULL); + + printk("mem_init_done ...........................................\n"); + mem_init_done = 1; + return; +} + +#ifdef CONFIG_BLK_DEV_INITRD +void free_initrd_mem(unsigned long start, unsigned long end) +{ + free_reserved_area((void *)start, (void *)end, -1, "initrd"); +} +#endif + +void free_initmem(void) +{ + free_initmem_default(-1); +} |