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);
+}