diff options
Diffstat (limited to 'target/linux/coldfire/files-2.6.31/arch/m68k/mm/cf-mmu.c')
| -rw-r--r-- | target/linux/coldfire/files-2.6.31/arch/m68k/mm/cf-mmu.c | 317 |
1 files changed, 317 insertions, 0 deletions
diff --git a/target/linux/coldfire/files-2.6.31/arch/m68k/mm/cf-mmu.c b/target/linux/coldfire/files-2.6.31/arch/m68k/mm/cf-mmu.c new file mode 100644 index 000000000..8e9685086 --- /dev/null +++ b/target/linux/coldfire/files-2.6.31/arch/m68k/mm/cf-mmu.c @@ -0,0 +1,317 @@ +/* + * linux/arch/m68k/mm/cf-mmu.c + * + * Based upon linux/arch/m68k/mm/sun3mmu.c + * Based upon linux/arch/ppc/mm/mmu_context.c + * + * Implementations of mm routines specific to the Coldfire MMU. + * + * Copyright (c) 2008 Freescale Semiconductor, Inc. + * Copyright Freescale Semiconductor, Inc. 2008-2009 + * Jason Jin Jason.Jin@freescale.com + * Shrek Wu B16972@freescale.com + */ + +#include <linux/signal.h> +#include <linux/sched.h> +#include <linux/mm.h> +#include <linux/swap.h> +#include <linux/kernel.h> +#include <linux/string.h> +#include <linux/types.h> +#include <linux/init.h> +#ifdef CONFIG_BLK_DEV_RAM +#include <linux/blkdev.h> +#endif +#include <linux/bootmem.h> + +#include <asm/setup.h> +#include <asm/uaccess.h> +#include <asm/page.h> +#include <asm/pgtable.h> +#include <asm/system.h> +#include <asm/machdep.h> +#include <asm/io.h> +#include <asm/mmu_context.h> +#include <asm/cf_pgalloc.h> + +#include <asm/coldfire.h> +#include <asm/tlbflush.h> + +#define KMAPAREA(x) ((x >= VMALLOC_START) && (x < KMAP_END)) + +#undef DEBUG + +#ifdef CONFIG_VDSO +unsigned long next_mmu_context; +#else +mm_context_t next_mmu_context; +#endif + +unsigned long context_map[LAST_CONTEXT / BITS_PER_LONG + 1]; + +atomic_t nr_free_contexts; +struct mm_struct *context_mm[LAST_CONTEXT+1]; +void steal_context(void); +#ifdef CONFIG_M5445X +void m68k_setup_node(int); +#endif +const char bad_pmd_string[] = "Bad pmd in pte_alloc: %08lx\n"; + +extern unsigned long empty_bad_page_table; +extern unsigned long empty_bad_page; +extern unsigned long num_pages; +#ifdef CONFIG_M5445X +extern unsigned long availmem; +#endif +extern char __init_begin, __init_end; + +/* + * Free memory used for system initialization. + */ +void free_initmem(void) +{ +#if 0 + unsigned long addr; + unsigned long start = (unsigned long)&__init_begin; + unsigned long end = (unsigned long)&__init_end; + + printk(KERN_INFO "free_initmem: __init_begin = 0x%lx __init_end = 0x%lx\n", start, end); + + addr = (unsigned long)&__init_begin; + for (; addr < (unsigned long)&__init_end; addr += PAGE_SIZE) { + /* not currently used */ + virt_to_page(addr)->flags &= ~(1 << PG_reserved); + init_page_count(virt_to_page(addr)); + free_page(addr); + totalram_pages++; + } +#endif +} + +/* + * Initialize the paging system. + */ +void __init paging_init(void) +{ + pgd_t * pg_dir; + pte_t * pg_table; + int i; + unsigned long address; + unsigned long next_pgtable; + unsigned long zones_size[MAX_NR_ZONES]; + unsigned long size; + enum zone_type zone; + + /* allocate zero page */ + empty_zero_page = (void *)alloc_bootmem_pages(PAGE_SIZE); + memset((void *)empty_zero_page, 0, PAGE_SIZE); + + /* zero kernel page directory */ + pg_dir = swapper_pg_dir; + memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir)); + /* + * setup page tables for PHYSRAM + */ + + /* starting loc in page directory */ + pg_dir += PAGE_OFFSET >> PGDIR_SHIFT; + + /* allocate page tables */ + size = num_pages * sizeof(pte_t); + size = (size + PAGE_SIZE) & ~(PAGE_SIZE-1); + next_pgtable = (unsigned long)alloc_bootmem_pages(size); + address = PAGE_OFFSET; + while (address < (unsigned long)high_memory) { + /* setup page table in page directory */ + pg_table = (pte_t *)next_pgtable; + next_pgtable += PTRS_PER_PTE * sizeof(pte_t); + pgd_val(*pg_dir) = (unsigned long)pg_table; + pg_dir++; + + /* create PTEs in page table */ + for (i=0; i<PTRS_PER_PTE; ++i, ++pg_table) { + pte_t pte = pfn_pte(virt_to_pfn(address), PAGE_INIT); + if (address >= (unsigned long)high_memory) + pte_val (pte) = 0; + + set_pte(pg_table, pte); + address += PAGE_SIZE; + } + } + + /* + * setup page tables for DMA area + */ + + /* starting loc in page directory */ + pg_dir = swapper_pg_dir; + pg_dir += CONFIG_DMA_BASE >> PGDIR_SHIFT; + + /* allocate page tables */ + size = (CONFIG_DMA_SIZE >> PAGE_SHIFT) * sizeof(pte_t); + size = (size + PAGE_SIZE) & ~(PAGE_SIZE-1); + next_pgtable = (unsigned long)alloc_bootmem_pages(size); + address = CONFIG_DMA_BASE; + while (address < (CONFIG_DMA_BASE + CONFIG_DMA_SIZE)) { + /* setup page table in page directory */ + pg_table = (pte_t *)next_pgtable; + next_pgtable += PTRS_PER_PTE * sizeof(pte_t); + pgd_val(*pg_dir) = (unsigned long)pg_table; + pg_dir++; + + /* create PTEs in page table */ + for (i=0; i<PTRS_PER_PTE; ++i, ++pg_table) { + pte_t pte = pfn_pte(virt_to_pfn(address), PAGE_INIT); + if (address >= (CONFIG_DMA_BASE + CONFIG_DMA_SIZE)) + pte_val (pte) = 0; + + set_pte(pg_table, pte); + address += PAGE_SIZE; + } + } + + /* + * setup zones + */ + + current->mm = NULL; + + /* clear zones */ + for (zone = 0; zone < MAX_NR_ZONES; zone++) + zones_size[zone] = 0x0; + + zones_size[ZONE_DMA] = CONFIG_DMA_SIZE >> PAGE_SHIFT; + zones_size[ZONE_NORMAL] = (((unsigned long)high_memory - + PAGE_OFFSET) >> PAGE_SHIFT) - + zones_size[ZONE_DMA]; + + free_area_init(zones_size); +} +/* + * Handle a missed TLB + */ +int cf_tlb_miss(struct pt_regs *regs, int write, int dtlb, int extension_word) +{ + struct mm_struct *mm; + pgd_t *pgd; + pmd_t *pmd; + pte_t *pte; + unsigned long mmuar; + int asid; + int flags; + + local_save_flags(flags); + local_irq_disable(); + + mmuar = ( dtlb ) ? regs->mmuar + : regs->pc + (extension_word * sizeof(long)); + + mm = (!user_mode(regs) && KMAPAREA(mmuar)) ? &init_mm : current->mm; + + if (!mm) { + local_irq_restore(flags); + return (-1); + } + + pgd = pgd_offset(mm, mmuar); + if (pgd_none(*pgd)) { + local_irq_restore(flags); + return (-1); + } + + pmd = pmd_offset(pgd, mmuar); + if (pmd_none(*pmd)) { + local_irq_restore(flags); + return (-1); + } + + pte = (KMAPAREA(mmuar)) ? pte_offset_kernel(pmd, mmuar) + : pte_offset_map(pmd, mmuar); + if (pte_none(*pte) || !pte_present(*pte)) { + local_irq_restore(flags); + return (-1); + } + + if (write) { + if (!pte_write(*pte)) { + local_irq_restore(flags); + return (-1); + } + set_pte(pte, pte_mkdirty(*pte)); + } + + set_pte(pte, pte_mkyoung(*pte)); + asid = cpu_context(mm) & 0xff; + if (!pte_dirty(*pte) && !KMAPAREA(mmuar)) + set_pte(pte, pte_wrprotect(*pte)); + + *MMUTR = (mmuar & PAGE_MASK) | (asid << CF_ASID_MMU_SHIFT) + | (((int)(pte->pte) & (int)CF_PAGE_MMUTR_MASK ) >> CF_PAGE_MMUTR_SHIFT) + | MMUTR_V; + + *MMUDR = (pte_val(*pte) & PAGE_MASK) + | ((pte->pte) & CF_PAGE_MMUDR_MASK) + | MMUDR_SZ8K | MMUDR_X; + + if ( dtlb ) + *MMUOR = MMUOR_ACC | MMUOR_UAA; + else + *MMUOR = MMUOR_ITLB | MMUOR_ACC | MMUOR_UAA; + + asm("nop"); + +#ifdef DEBUG + printk("cf_tlb_miss: va=%lx, pa=%lx\n", (mmuar & PAGE_MASK), + (pte_val(*pte) & PAGE_MASK)); +#endif + local_irq_restore(flags); + return (0); +} + + +/* + * Context Management + * + * Based on arch/ppc/mmu_context.c + */ + +/* + * Initialize the context management system. + */ +void __init mmu_context_init(void) +{ + /* + * Some processors have too few contexts to reserve one for + * init_mm, and require using context 0 for a normal task. + * Other processors reserve the use of context zero for the kernel. + * This code assumes FIRST_CONTEXT < 32. + */ + context_map[0] = (1 << FIRST_CONTEXT) - 1; + next_mmu_context = FIRST_CONTEXT; + atomic_set(&nr_free_contexts, LAST_CONTEXT - FIRST_CONTEXT + 1); +} + +/* + * Steal a context from a task that has one at the moment. + * This is only used on 8xx and 4xx and we presently assume that + * they don't do SMP. If they do then thicfpgalloc.hs will have to check + * whether the MM we steal is in use. + * We also assume that this is only used on systems that don't + * use an MMU hash table - this is true for 8xx and 4xx. + * This isn't an LRU system, it just frees up each context in + * turn (sort-of pseudo-random replacement :). This would be the + * place to implement an LRU scheme if anyone was motivated to do it. + * -- paulus + */ +void steal_context(void) +{ + struct mm_struct *mm; + /* free up context `next_mmu_context' */ + /* if we shouldn't free context 0, don't... */ + if (next_mmu_context < FIRST_CONTEXT) + next_mmu_context = FIRST_CONTEXT; + mm = context_mm[next_mmu_context]; + flush_tlb_mm(mm); + destroy_context(mm); +} |