diff options
Diffstat (limited to 'arch/sh/mm/fault.c')
| -rw-r--r-- | arch/sh/mm/fault.c | 374 |
1 files changed, 374 insertions, 0 deletions
diff --git a/arch/sh/mm/fault.c b/arch/sh/mm/fault.c new file mode 100644 index 000000000000..7abba2161da6 --- /dev/null +++ b/arch/sh/mm/fault.c @@ -0,0 +1,374 @@ +/* $Id: fault.c,v 1.14 2004/01/13 05:52:11 kkojima Exp $ + * + * linux/arch/sh/mm/fault.c + * Copyright (C) 1999 Niibe Yutaka + * Copyright (C) 2003 Paul Mundt + * + * Based on linux/arch/i386/mm/fault.c: + * Copyright (C) 1995 Linus Torvalds + */ + +#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/smp.h> +#include <linux/smp_lock.h> +#include <linux/interrupt.h> +#include <linux/module.h> + +#include <asm/system.h> +#include <asm/io.h> +#include <asm/uaccess.h> +#include <asm/pgalloc.h> +#include <asm/mmu_context.h> +#include <asm/cacheflush.h> +#include <asm/kgdb.h> + +extern void die(const char *,struct pt_regs *,long); + +/* + * This routine handles page faults. It determines the address, + * and the problem, and then passes it off to one of the appropriate + * routines. + */ +asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long writeaccess, + unsigned long address) +{ + struct task_struct *tsk; + struct mm_struct *mm; + struct vm_area_struct * vma; + unsigned long page; + +#ifdef CONFIG_SH_KGDB + if (kgdb_nofault && kgdb_bus_err_hook) + kgdb_bus_err_hook(); +#endif + + tsk = current; + mm = tsk->mm; + + /* + * If we're in an interrupt or have no user + * context, we must not take the fault.. + */ + if (in_atomic() || !mm) + goto no_context; + + down_read(&mm->mmap_sem); + + vma = find_vma(mm, address); + if (!vma) + goto bad_area; + if (vma->vm_start <= address) + goto good_area; + if (!(vma->vm_flags & VM_GROWSDOWN)) + goto bad_area; + if (expand_stack(vma, address)) + goto bad_area; +/* + * Ok, we have a good vm_area for this memory access, so + * we can handle it.. + */ +good_area: + if (writeaccess) { + if (!(vma->vm_flags & VM_WRITE)) + goto bad_area; + } else { + if (!(vma->vm_flags & (VM_READ | VM_EXEC))) + goto bad_area; + } + + /* + * If for any reason at all we couldn't handle the fault, + * make sure we exit gracefully rather than endlessly redo + * the fault. + */ +survive: + switch (handle_mm_fault(mm, vma, address, writeaccess)) { + case VM_FAULT_MINOR: + tsk->min_flt++; + break; + case VM_FAULT_MAJOR: + tsk->maj_flt++; + break; + case VM_FAULT_SIGBUS: + goto do_sigbus; + case VM_FAULT_OOM: + goto out_of_memory; + default: + BUG(); + } + + up_read(&mm->mmap_sem); + return; + +/* + * Something tried to access memory that isn't in our memory map.. + * Fix it, but check if it's kernel or user first.. + */ +bad_area: + up_read(&mm->mmap_sem); + + if (user_mode(regs)) { + tsk->thread.address = address; + tsk->thread.error_code = writeaccess; + force_sig(SIGSEGV, tsk); + return; + } + +no_context: + /* Are we prepared to handle this kernel fault? */ + if (fixup_exception(regs)) + return; + +/* + * Oops. The kernel tried to access some bad page. We'll have to + * terminate things with extreme prejudice. + * + */ + if (address < PAGE_SIZE) + printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference"); + else + printk(KERN_ALERT "Unable to handle kernel paging request"); + printk(" at virtual address %08lx\n", address); + printk(KERN_ALERT "pc = %08lx\n", regs->pc); + asm volatile("mov.l %1, %0" + : "=r" (page) + : "m" (__m(MMU_TTB))); + if (page) { + page = ((unsigned long *) page)[address >> 22]; + printk(KERN_ALERT "*pde = %08lx\n", page); + if (page & _PAGE_PRESENT) { + page &= PAGE_MASK; + address &= 0x003ff000; + page = ((unsigned long *) __va(page))[address >> PAGE_SHIFT]; + printk(KERN_ALERT "*pte = %08lx\n", page); + } + } + die("Oops", regs, writeaccess); + do_exit(SIGKILL); + +/* + * We ran out of memory, or some other thing happened to us that made + * us unable to handle the page fault gracefully. + */ +out_of_memory: + up_read(&mm->mmap_sem); + if (current->pid == 1) { + yield(); + down_read(&mm->mmap_sem); + goto survive; + } + printk("VM: killing process %s\n", tsk->comm); + if (user_mode(regs)) + do_exit(SIGKILL); + goto no_context; + +do_sigbus: + up_read(&mm->mmap_sem); + + /* + * Send a sigbus, regardless of whether we were in kernel + * or user mode. + */ + tsk->thread.address = address; + tsk->thread.error_code = writeaccess; + tsk->thread.trap_no = 14; + force_sig(SIGBUS, tsk); + + /* Kernel mode? Handle exceptions or die */ + if (!user_mode(regs)) + goto no_context; +} + +/* + * Called with interrupt disabled. + */ +asmlinkage int __do_page_fault(struct pt_regs *regs, unsigned long writeaccess, + unsigned long address) +{ + unsigned long addrmax = P4SEG; + pgd_t *dir; + pmd_t *pmd; + pte_t *pte; + pte_t entry; + +#ifdef CONFIG_SH_KGDB + if (kgdb_nofault && kgdb_bus_err_hook) + kgdb_bus_err_hook(); +#endif + +#ifdef CONFIG_SH_STORE_QUEUES + addrmax = P4SEG_STORE_QUE + 0x04000000; +#endif + + if (address >= P3SEG && address < addrmax) + dir = pgd_offset_k(address); + else if (address >= TASK_SIZE) + return 1; + else if (!current->mm) + return 1; + else + dir = pgd_offset(current->mm, address); + + pmd = pmd_offset(dir, address); + if (pmd_none(*pmd)) + return 1; + if (pmd_bad(*pmd)) { + pmd_ERROR(*pmd); + pmd_clear(pmd); + return 1; + } + pte = pte_offset_kernel(pmd, address); + entry = *pte; + if (pte_none(entry) || pte_not_present(entry) + || (writeaccess && !pte_write(entry))) + return 1; + + if (writeaccess) + entry = pte_mkdirty(entry); + entry = pte_mkyoung(entry); + +#ifdef CONFIG_CPU_SH4 + /* + * ITLB is not affected by "ldtlb" instruction. + * So, we need to flush the entry by ourselves. + */ + + { + unsigned long flags; + local_irq_save(flags); + __flush_tlb_page(get_asid(), address&PAGE_MASK); + local_irq_restore(flags); + } +#endif + + set_pte(pte, entry); + update_mmu_cache(NULL, address, entry); + + return 0; +} + +void flush_tlb_page(struct vm_area_struct *vma, unsigned long page) +{ + if (vma->vm_mm && vma->vm_mm->context != NO_CONTEXT) { + unsigned long flags; + unsigned long asid; + unsigned long saved_asid = MMU_NO_ASID; + + asid = vma->vm_mm->context & MMU_CONTEXT_ASID_MASK; + page &= PAGE_MASK; + + local_irq_save(flags); + if (vma->vm_mm != current->mm) { + saved_asid = get_asid(); + set_asid(asid); + } + __flush_tlb_page(asid, page); + if (saved_asid != MMU_NO_ASID) + set_asid(saved_asid); + local_irq_restore(flags); + } +} + +void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, + unsigned long end) +{ + struct mm_struct *mm = vma->vm_mm; + + if (mm->context != NO_CONTEXT) { + unsigned long flags; + int size; + + local_irq_save(flags); + size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT; + if (size > (MMU_NTLB_ENTRIES/4)) { /* Too many TLB to flush */ + mm->context = NO_CONTEXT; + if (mm == current->mm) + activate_context(mm); + } else { + unsigned long asid = mm->context&MMU_CONTEXT_ASID_MASK; + unsigned long saved_asid = MMU_NO_ASID; + + start &= PAGE_MASK; + end += (PAGE_SIZE - 1); + end &= PAGE_MASK; + if (mm != current->mm) { + saved_asid = get_asid(); + set_asid(asid); + } + while (start < end) { + __flush_tlb_page(asid, start); + start += PAGE_SIZE; + } + if (saved_asid != MMU_NO_ASID) + set_asid(saved_asid); + } + local_irq_restore(flags); + } +} + +void flush_tlb_kernel_range(unsigned long start, unsigned long end) +{ + unsigned long flags; + int size; + + local_irq_save(flags); + size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT; + if (size > (MMU_NTLB_ENTRIES/4)) { /* Too many TLB to flush */ + flush_tlb_all(); + } else { + unsigned long asid = init_mm.context&MMU_CONTEXT_ASID_MASK; + unsigned long saved_asid = get_asid(); + + start &= PAGE_MASK; + end += (PAGE_SIZE - 1); + end &= PAGE_MASK; + set_asid(asid); + while (start < end) { + __flush_tlb_page(asid, start); + start += PAGE_SIZE; + } + set_asid(saved_asid); + } + local_irq_restore(flags); +} + +void flush_tlb_mm(struct mm_struct *mm) +{ + /* Invalidate all TLB of this process. */ + /* Instead of invalidating each TLB, we get new MMU context. */ + if (mm->context != NO_CONTEXT) { + unsigned long flags; + + local_irq_save(flags); + mm->context = NO_CONTEXT; + if (mm == current->mm) + activate_context(mm); + local_irq_restore(flags); + } +} + +void flush_tlb_all(void) +{ + unsigned long flags, status; + + /* + * Flush all the TLB. + * + * Write to the MMU control register's bit: + * TF-bit for SH-3, TI-bit for SH-4. + * It's same position, bit #2. + */ + local_irq_save(flags); + status = ctrl_inl(MMUCR); + status |= 0x04; + ctrl_outl(status, MMUCR); + local_irq_restore(flags); +} |