+++ /dev/null
-/*
- * 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);
-}
projects / 15.05 / openwrt.git / blobdiff