sh: lockless UTLB miss fast-path.

[powerpc.git] / arch / sh / mm / fault.c

diff --git a/arch/sh/mm/fault.c b/arch/sh/mm/fault.c
index 0b3eaf6..60d74f7 100644 (file)
--- a/arch/sh/mm/fault.c
+++ b/arch/sh/mm/fault.c
@@ -33,6 +33,7 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
        struct mm_struct *mm;
        struct vm_area_struct * vma;
        int si_code;
+       int fault;
        siginfo_t info;
 
        trace_hardirqs_on();
@@ -124,20 +125,18 @@ good_area:
         * 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:
+       fault = handle_mm_fault(mm, vma, address, writeaccess);
+       if (unlikely(fault & VM_FAULT_ERROR)) {
+               if (fault & VM_FAULT_OOM)
                        goto out_of_memory;
-               default:
-                       BUG();
+               else if (fault & VM_FAULT_SIGBUS)
+                       goto do_sigbus;
+               BUG();
        }
+       if (fault & VM_FAULT_MAJOR)
+               tsk->maj_flt++;
+       else
+               tsk->min_flt++;
 
        up_read(&mm->mmap_sem);
        return;
@@ -185,8 +184,7 @@ no_context:
                printk(KERN_ALERT "pc = %08lx\n", regs->pc);
                page = (unsigned long)get_TTB();
                if (page) {
-                       page = ((__typeof__(page) *) __va(page))[address >>
-                                                                PGDIR_SHIFT];
+                       page = ((__typeof__(page) *)page)[address >> PGDIR_SHIFT];
                        printk(KERN_ALERT "*pde = %08lx\n", page);
                        if (page & _PAGE_PRESENT) {
                                page &= PAGE_MASK;
@@ -209,14 +207,14 @@ no_context:
  */
 out_of_memory:
        up_read(&mm->mmap_sem);
-       if (is_init(current)) {
+       if (is_global_init(current)) {
                yield();
                down_read(&mm->mmap_sem);
                goto survive;
        }
        printk("VM: killing process %s\n", tsk->comm);
        if (user_mode(regs))
-               do_exit(SIGKILL);
+               do_group_exit(SIGKILL);
        goto no_context;
 
 do_sigbus:
@@ -260,9 +258,6 @@ asmlinkage int __kprobes __do_page_fault(struct pt_regs *regs,
        pmd_t *pmd;
        pte_t *pte;
        pte_t entry;
-       struct mm_struct *mm = current->mm;
-       spinlock_t *ptl = NULL;
-       int ret = 1;
 
 #ifdef CONFIG_SH_KGDB
        if (kgdb_nofault && kgdb_bus_err_hook)
@@ -276,12 +271,11 @@ asmlinkage int __kprobes __do_page_fault(struct pt_regs *regs,
         */
        if (address >= P3SEG && address < P3_ADDR_MAX) {
                pgd = pgd_offset_k(address);
-               mm = NULL;
        } else {
-               if (unlikely(address >= TASK_SIZE || !mm))
+               if (unlikely(address >= TASK_SIZE || !current->mm))
                        return 1;
 
-               pgd = pgd_offset(mm, address);
+               pgd = pgd_offset(current->mm, address);
        }
 
        pud = pud_offset(pgd, address);
@@ -291,34 +285,19 @@ asmlinkage int __kprobes __do_page_fault(struct pt_regs *regs,
        if (pmd_none_or_clear_bad(pmd))
                return 1;
 
-       if (mm)
-               pte = pte_offset_map_lock(mm, pmd, address, &ptl);
-       else
-               pte = pte_offset_kernel(pmd, address);
-
+       pte = pte_offset_kernel(pmd, address);
        entry = *pte;
        if (unlikely(pte_none(entry) || pte_not_present(entry)))
-               goto unlock;
+               return 1;
        if (unlikely(writeaccess && !pte_write(entry)))
-               goto unlock;
+               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.
-        */
-       local_flush_tlb_one(get_asid(), address & PAGE_MASK);
-#endif
-
        set_pte(pte, entry);
        update_mmu_cache(NULL, address, entry);
-       ret = 0;
-unlock:
-       if (mm)
-               pte_unmap_unlock(pte, ptl);
-       return ret;
+
+       return 0;
 }