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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-17 02:20:36 +0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-17 02:20:36 +0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/sh/mm/fault.c
downloadlinux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/sh/mm/fault.c')
-rw-r--r--arch/sh/mm/fault.c374
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);
+}