| /* |
| * arch/sh/mm/tlb-flush_64.c |
| * |
| * Copyright (C) 2000, 2001 Paolo Alberelli |
| * Copyright (C) 2003 Richard Curnow (/proc/tlb, bug fixes) |
| * Copyright (C) 2003 - 2009 Paul Mundt |
| * |
| * This file is subject to the terms and conditions of the GNU General Public |
| * License. See the file "COPYING" in the main directory of this archive |
| * for more details. |
| */ |
| #include <linux/signal.h> |
| #include <linux/rwsem.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/perf_counter.h> |
| #include <linux/interrupt.h> |
| #include <asm/system.h> |
| #include <asm/io.h> |
| #include <asm/tlb.h> |
| #include <asm/uaccess.h> |
| #include <asm/pgalloc.h> |
| #include <asm/mmu_context.h> |
| |
| extern void die(const char *,struct pt_regs *,long); |
| |
| #define PFLAG(val,flag) (( (val) & (flag) ) ? #flag : "" ) |
| #define PPROT(flag) PFLAG(pgprot_val(prot),flag) |
| |
| static inline void print_prots(pgprot_t prot) |
| { |
| printk("prot is 0x%08lx\n",pgprot_val(prot)); |
| |
| printk("%s %s %s %s %s\n",PPROT(_PAGE_SHARED),PPROT(_PAGE_READ), |
| PPROT(_PAGE_EXECUTE),PPROT(_PAGE_WRITE),PPROT(_PAGE_USER)); |
| } |
| |
| static inline void print_vma(struct vm_area_struct *vma) |
| { |
| printk("vma start 0x%08lx\n", vma->vm_start); |
| printk("vma end 0x%08lx\n", vma->vm_end); |
| |
| print_prots(vma->vm_page_prot); |
| printk("vm_flags 0x%08lx\n", vma->vm_flags); |
| } |
| |
| static inline void print_task(struct task_struct *tsk) |
| { |
| printk("Task pid %d\n", task_pid_nr(tsk)); |
| } |
| |
| static pte_t *lookup_pte(struct mm_struct *mm, unsigned long address) |
| { |
| pgd_t *dir; |
| pud_t *pud; |
| pmd_t *pmd; |
| pte_t *pte; |
| pte_t entry; |
| |
| dir = pgd_offset(mm, address); |
| if (pgd_none(*dir)) |
| return NULL; |
| |
| pud = pud_offset(dir, address); |
| if (pud_none(*pud)) |
| return NULL; |
| |
| pmd = pmd_offset(pud, address); |
| if (pmd_none(*pmd)) |
| return NULL; |
| |
| pte = pte_offset_kernel(pmd, address); |
| entry = *pte; |
| if (pte_none(entry) || !pte_present(entry)) |
| return NULL; |
| |
| return pte; |
| } |
| |
| /* |
| * 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 textaccess, unsigned long address) |
| { |
| struct task_struct *tsk; |
| struct mm_struct *mm; |
| struct vm_area_struct * vma; |
| const struct exception_table_entry *fixup; |
| pte_t *pte; |
| int fault; |
| |
| /* SIM |
| * Note this is now called with interrupts still disabled |
| * This is to cope with being called for a missing IO port |
| * address with interrupts disabled. This should be fixed as |
| * soon as we have a better 'fast path' miss handler. |
| * |
| * Plus take care how you try and debug this stuff. |
| * For example, writing debug data to a port which you |
| * have just faulted on is not going to work. |
| */ |
| |
| tsk = current; |
| mm = tsk->mm; |
| |
| /* Not an IO address, so reenable interrupts */ |
| local_irq_enable(); |
| |
| perf_swcounter_event(PERF_COUNT_SW_PAGE_FAULTS, 1, 0, regs, address); |
| |
| /* |
| * If we're in an interrupt or have no user |
| * context, we must not take the fault.. |
| */ |
| if (in_atomic() || !mm) |
| goto no_context; |
| |
| /* TLB misses upon some cache flushes get done under cli() */ |
| down_read(&mm->mmap_sem); |
| |
| vma = find_vma(mm, address); |
| |
| if (!vma) { |
| #ifdef DEBUG_FAULT |
| print_task(tsk); |
| printk("%s:%d fault, address is 0x%08x PC %016Lx textaccess %d writeaccess %d\n", |
| __func__, __LINE__, |
| address,regs->pc,textaccess,writeaccess); |
| show_regs(regs); |
| #endif |
| goto bad_area; |
| } |
| if (vma->vm_start <= address) { |
| goto good_area; |
| } |
| |
| if (!(vma->vm_flags & VM_GROWSDOWN)) { |
| #ifdef DEBUG_FAULT |
| print_task(tsk); |
| printk("%s:%d fault, address is 0x%08x PC %016Lx textaccess %d writeaccess %d\n", |
| __func__, __LINE__, |
| address,regs->pc,textaccess,writeaccess); |
| show_regs(regs); |
| |
| print_vma(vma); |
| #endif |
| goto bad_area; |
| } |
| if (expand_stack(vma, address)) { |
| #ifdef DEBUG_FAULT |
| print_task(tsk); |
| printk("%s:%d fault, address is 0x%08x PC %016Lx textaccess %d writeaccess %d\n", |
| __func__, __LINE__, |
| address,regs->pc,textaccess,writeaccess); |
| show_regs(regs); |
| #endif |
| goto bad_area; |
| } |
| /* |
| * Ok, we have a good vm_area for this memory access, so |
| * we can handle it.. |
| */ |
| good_area: |
| if (textaccess) { |
| if (!(vma->vm_flags & VM_EXEC)) |
| goto bad_area; |
| } else { |
| if (writeaccess) { |
| if (!(vma->vm_flags & VM_WRITE)) |
| goto bad_area; |
| } else { |
| if (!(vma->vm_flags & VM_READ)) |
| 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: |
| fault = handle_mm_fault(mm, vma, address, writeaccess ? FAULT_FLAG_WRITE : 0); |
| if (unlikely(fault & VM_FAULT_ERROR)) { |
| if (fault & VM_FAULT_OOM) |
| goto out_of_memory; |
| else if (fault & VM_FAULT_SIGBUS) |
| goto do_sigbus; |
| BUG(); |
| } |
| |
| if (fault & VM_FAULT_MAJOR) { |
| tsk->maj_flt++; |
| perf_swcounter_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, 0, |
| regs, address); |
| } else { |
| tsk->min_flt++; |
| perf_swcounter_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, 0, |
| regs, address); |
| } |
| |
| /* If we get here, the page fault has been handled. Do the TLB refill |
| now from the newly-setup PTE, to avoid having to fault again right |
| away on the same instruction. */ |
| pte = lookup_pte (mm, address); |
| if (!pte) { |
| /* From empirical evidence, we can get here, due to |
| !pte_present(pte). (e.g. if a swap-in occurs, and the page |
| is swapped back out again before the process that wanted it |
| gets rescheduled?) */ |
| goto no_pte; |
| } |
| |
| __do_tlb_refill(address, textaccess, pte); |
| |
| no_pte: |
| |
| 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: |
| #ifdef DEBUG_FAULT |
| printk("fault:bad area\n"); |
| #endif |
| up_read(&mm->mmap_sem); |
| |
| if (user_mode(regs)) { |
| static int count=0; |
| siginfo_t info; |
| if (count < 4) { |
| /* This is really to help debug faults when starting |
| * usermode, so only need a few */ |
| count++; |
| printk("user mode bad_area address=%08lx pid=%d (%s) pc=%08lx\n", |
| address, task_pid_nr(current), current->comm, |
| (unsigned long) regs->pc); |
| #if 0 |
| show_regs(regs); |
| #endif |
| } |
| if (is_global_init(tsk)) { |
| panic("INIT had user mode bad_area\n"); |
| } |
| tsk->thread.address = address; |
| tsk->thread.error_code = writeaccess; |
| info.si_signo = SIGSEGV; |
| info.si_errno = 0; |
| info.si_addr = (void *) address; |
| force_sig_info(SIGSEGV, &info, tsk); |
| return; |
| } |
| |
| no_context: |
| #ifdef DEBUG_FAULT |
| printk("fault:No context\n"); |
| #endif |
| /* Are we prepared to handle this kernel fault? */ |
| fixup = search_exception_tables(regs->pc); |
| if (fixup) { |
| regs->pc = fixup->fixup; |
| 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%08Lx\n", regs->pc >> 32, regs->pc & 0xffffffff); |
| 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: |
| if (is_global_init(current)) { |
| panic("INIT out of memory\n"); |
| yield(); |
| goto survive; |
| } |
| printk("fault:Out of memory\n"); |
| up_read(&mm->mmap_sem); |
| 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_group_exit(SIGKILL); |
| goto no_context; |
| |
| do_sigbus: |
| printk("fault:Do sigbus\n"); |
| 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; |
| } |
| |
| void local_flush_tlb_one(unsigned long asid, unsigned long page) |
| { |
| unsigned long long match, pteh=0, lpage; |
| unsigned long tlb; |
| |
| /* |
| * Sign-extend based on neff. |
| */ |
| lpage = neff_sign_extend(page); |
| match = (asid << PTEH_ASID_SHIFT) | PTEH_VALID; |
| match |= lpage; |
| |
| for_each_itlb_entry(tlb) { |
| asm volatile ("getcfg %1, 0, %0" |
| : "=r" (pteh) |
| : "r" (tlb) ); |
| |
| if (pteh == match) { |
| __flush_tlb_slot(tlb); |
| break; |
| } |
| } |
| |
| for_each_dtlb_entry(tlb) { |
| asm volatile ("getcfg %1, 0, %0" |
| : "=r" (pteh) |
| : "r" (tlb) ); |
| |
| if (pteh == match) { |
| __flush_tlb_slot(tlb); |
| break; |
| } |
| |
| } |
| } |
| |
| void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page) |
| { |
| unsigned long flags; |
| |
| if (vma->vm_mm) { |
| page &= PAGE_MASK; |
| local_irq_save(flags); |
| local_flush_tlb_one(get_asid(), page); |
| local_irq_restore(flags); |
| } |
| } |
| |
| void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start, |
| unsigned long end) |
| { |
| unsigned long flags; |
| unsigned long long match, pteh=0, pteh_epn, pteh_low; |
| unsigned long tlb; |
| unsigned int cpu = smp_processor_id(); |
| struct mm_struct *mm; |
| |
| mm = vma->vm_mm; |
| if (cpu_context(cpu, mm) == NO_CONTEXT) |
| return; |
| |
| local_irq_save(flags); |
| |
| start &= PAGE_MASK; |
| end &= PAGE_MASK; |
| |
| match = (cpu_asid(cpu, mm) << PTEH_ASID_SHIFT) | PTEH_VALID; |
| |
| /* Flush ITLB */ |
| for_each_itlb_entry(tlb) { |
| asm volatile ("getcfg %1, 0, %0" |
| : "=r" (pteh) |
| : "r" (tlb) ); |
| |
| pteh_epn = pteh & PAGE_MASK; |
| pteh_low = pteh & ~PAGE_MASK; |
| |
| if (pteh_low == match && pteh_epn >= start && pteh_epn <= end) |
| __flush_tlb_slot(tlb); |
| } |
| |
| /* Flush DTLB */ |
| for_each_dtlb_entry(tlb) { |
| asm volatile ("getcfg %1, 0, %0" |
| : "=r" (pteh) |
| : "r" (tlb) ); |
| |
| pteh_epn = pteh & PAGE_MASK; |
| pteh_low = pteh & ~PAGE_MASK; |
| |
| if (pteh_low == match && pteh_epn >= start && pteh_epn <= end) |
| __flush_tlb_slot(tlb); |
| } |
| |
| local_irq_restore(flags); |
| } |
| |
| void local_flush_tlb_mm(struct mm_struct *mm) |
| { |
| unsigned long flags; |
| unsigned int cpu = smp_processor_id(); |
| |
| if (cpu_context(cpu, mm) == NO_CONTEXT) |
| return; |
| |
| local_irq_save(flags); |
| |
| cpu_context(cpu, mm) = NO_CONTEXT; |
| if (mm == current->mm) |
| activate_context(mm, cpu); |
| |
| local_irq_restore(flags); |
| } |
| |
| void local_flush_tlb_all(void) |
| { |
| /* Invalidate all, including shared pages, excluding fixed TLBs */ |
| unsigned long flags, tlb; |
| |
| local_irq_save(flags); |
| |
| /* Flush each ITLB entry */ |
| for_each_itlb_entry(tlb) |
| __flush_tlb_slot(tlb); |
| |
| /* Flush each DTLB entry */ |
| for_each_dtlb_entry(tlb) |
| __flush_tlb_slot(tlb); |
| |
| local_irq_restore(flags); |
| } |
| |
| void local_flush_tlb_kernel_range(unsigned long start, unsigned long end) |
| { |
| /* FIXME: Optimize this later.. */ |
| flush_tlb_all(); |
| } |
| |
| void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t pte) |
| { |
| } |