+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0
-/*
- * linux/arch/m32r/mm/fault.c
- *
- * Copyright (c) 2001, 2002 Hitoshi Yamamoto, and H. Kondo
- * Copyright (c) 2004 Naoto Sugai, NIIBE Yutaka
- *
- * Some code taken from i386 version.
- * 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/interrupt.h>
-#include <linux/init.h>
-#include <linux/tty.h>
-#include <linux/vt_kern.h> /* For unblank_screen() */
-#include <linux/highmem.h>
-#include <linux/extable.h>
-#include <linux/uaccess.h>
-
-#include <asm/m32r.h>
-#include <asm/hardirq.h>
-#include <asm/mmu_context.h>
-#include <asm/tlbflush.h>
-
-extern void die(const char *, struct pt_regs *, long);
-
-#ifndef CONFIG_SMP
-asmlinkage unsigned int tlb_entry_i_dat;
-asmlinkage unsigned int tlb_entry_d_dat;
-#define tlb_entry_i tlb_entry_i_dat
-#define tlb_entry_d tlb_entry_d_dat
-#else
-unsigned int tlb_entry_i_dat[NR_CPUS];
-unsigned int tlb_entry_d_dat[NR_CPUS];
-#define tlb_entry_i tlb_entry_i_dat[smp_processor_id()]
-#define tlb_entry_d tlb_entry_d_dat[smp_processor_id()]
-#endif
-
-extern void init_tlb(void);
-
-/*======================================================================*
- * do_page_fault()
- *======================================================================*
- * This routine handles page faults. It determines the address,
- * and the problem, and then passes it off to one of the appropriate
- * routines.
- *
- * ARGUMENT:
- * regs : M32R SP reg.
- * error_code : See below
- * address : M32R MMU MDEVA reg. (Operand ACE)
- * : M32R BPC reg. (Instruction ACE)
- *
- * error_code :
- * bit 0 == 0 means no page found, 1 means protection fault
- * bit 1 == 0 means read, 1 means write
- * bit 2 == 0 means kernel, 1 means user-mode
- * bit 3 == 0 means data, 1 means instruction
- *======================================================================*/
-#define ACE_PROTECTION 1
-#define ACE_WRITE 2
-#define ACE_USERMODE 4
-#define ACE_INSTRUCTION 8
-
-asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code,
- unsigned long address)
-{
- struct task_struct *tsk;
- struct mm_struct *mm;
- struct vm_area_struct * vma;
- unsigned long page, addr;
- unsigned long flags = 0;
- int fault;
- siginfo_t info;
-
- /*
- * If BPSW IE bit enable --> set PSW IE bit
- */
- if (regs->psw & M32R_PSW_BIE)
- local_irq_enable();
-
- tsk = current;
-
- info.si_code = SEGV_MAPERR;
-
- /*
- * We fault-in kernel-space virtual memory on-demand. The
- * 'reference' page table is init_mm.pgd.
- *
- * NOTE! We MUST NOT take any locks for this case. We may
- * be in an interrupt or a critical region, and should
- * only copy the information from the master page table,
- * nothing more.
- *
- * This verifies that the fault happens in kernel space
- * (error_code & ACE_USERMODE) == 0, and that the fault was not a
- * protection error (error_code & ACE_PROTECTION) == 0.
- */
- if (address >= TASK_SIZE && !(error_code & ACE_USERMODE))
- goto vmalloc_fault;
-
- mm = tsk->mm;
-
- /*
- * If we're in an interrupt or have no user context or have pagefaults
- * disabled then we must not take the fault.
- */
- if (faulthandler_disabled() || !mm)
- goto bad_area_nosemaphore;
-
- if (error_code & ACE_USERMODE)
- flags |= FAULT_FLAG_USER;
-
- /* When running in the kernel we expect faults to occur only to
- * addresses in user space. All other faults represent errors in the
- * kernel and should generate an OOPS. Unfortunately, in the case of an
- * erroneous fault occurring in a code path which already holds mmap_sem
- * we will deadlock attempting to validate the fault against the
- * address space. Luckily the kernel only validly references user
- * space from well defined areas of code, which are listed in the
- * exceptions table.
- *
- * As the vast majority of faults will be valid we will only perform
- * the source reference check when there is a possibility of a deadlock.
- * Attempt to lock the address space, if we cannot we then validate the
- * source. If this is invalid we can skip the address space check,
- * thus avoiding the deadlock.
- */
- if (!down_read_trylock(&mm->mmap_sem)) {
- if ((error_code & ACE_USERMODE) == 0 &&
- !search_exception_tables(regs->psw))
- goto bad_area_nosemaphore;
- 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 (error_code & ACE_USERMODE) {
- /*
- * accessing the stack below "spu" is always a bug.
- * The "+ 4" is there due to the push instruction
- * doing pre-decrement on the stack and that
- * doesn't show up until later..
- */
- if (address + 4 < regs->spu)
- 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:
- info.si_code = SEGV_ACCERR;
- switch (error_code & (ACE_WRITE|ACE_PROTECTION)) {
- default: /* 3: write, present */
- /* fall through */
- case ACE_WRITE: /* write, not present */
- if (!(vma->vm_flags & VM_WRITE))
- goto bad_area;
- flags |= FAULT_FLAG_WRITE;
- break;
- case ACE_PROTECTION: /* read, present */
- case 0: /* read, not present */
- if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
- goto bad_area;
- }
-
- /*
- * For instruction access exception, check if the area is executable
- */
- if ((error_code & ACE_INSTRUCTION) && !(vma->vm_flags & 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.
- */
- addr = (address & PAGE_MASK);
- set_thread_fault_code(error_code);
- fault = handle_mm_fault(vma, addr, flags);
- if (unlikely(fault & VM_FAULT_ERROR)) {
- if (fault & VM_FAULT_OOM)
- goto out_of_memory;
- else if (fault & VM_FAULT_SIGSEGV)
- goto bad_area;
- else if (fault & VM_FAULT_SIGBUS)
- goto do_sigbus;
- BUG();
- }
- if (fault & VM_FAULT_MAJOR)
- tsk->maj_flt++;
- else
- tsk->min_flt++;
- set_thread_fault_code(0);
- 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);
-
-bad_area_nosemaphore:
- /* User mode accesses just cause a SIGSEGV */
- if (error_code & ACE_USERMODE) {
- tsk->thread.address = address;
- tsk->thread.error_code = error_code | (address >= TASK_SIZE);
- tsk->thread.trap_no = 14;
- info.si_signo = SIGSEGV;
- info.si_errno = 0;
- /* info.si_code has been set above */
- info.si_addr = (void __user *)address;
- force_sig_info(SIGSEGV, &info, 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.
- */
-
- bust_spinlocks(1);
-
- 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 " printing bpc:\n");
- printk("%08lx\n", regs->bpc);
- page = *(unsigned long *)MPTB;
- page = ((unsigned long *) page)[address >> PGDIR_SHIFT];
- 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, error_code);
- bust_spinlocks(0);
- 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 (!(error_code & ACE_USERMODE))
- goto no_context;
- pagefault_out_of_memory();
- return;
-
-do_sigbus:
- up_read(&mm->mmap_sem);
-
- /* Kernel mode? Handle exception or die */
- if (!(error_code & ACE_USERMODE))
- goto no_context;
-
- tsk->thread.address = address;
- tsk->thread.error_code = error_code;
- tsk->thread.trap_no = 14;
- info.si_signo = SIGBUS;
- info.si_errno = 0;
- info.si_code = BUS_ADRERR;
- info.si_addr = (void __user *)address;
- force_sig_info(SIGBUS, &info, tsk);
- return;
-
-vmalloc_fault:
- {
- /*
- * Synchronize this task's top level page-table
- * with the 'reference' page table.
- *
- * Do _not_ use "tsk" here. We might be inside
- * an interrupt in the middle of a task switch..
- */
- int offset = pgd_index(address);
- pgd_t *pgd, *pgd_k;
- pmd_t *pmd, *pmd_k;
- pte_t *pte_k;
-
- pgd = (pgd_t *)*(unsigned long *)MPTB;
- pgd = offset + (pgd_t *)pgd;
- pgd_k = init_mm.pgd + offset;
-
- if (!pgd_present(*pgd_k))
- goto no_context;
-
- /*
- * set_pgd(pgd, *pgd_k); here would be useless on PAE
- * and redundant with the set_pmd() on non-PAE.
- */
-
- pmd = pmd_offset(pgd, address);
- pmd_k = pmd_offset(pgd_k, address);
- if (!pmd_present(*pmd_k))
- goto no_context;
- set_pmd(pmd, *pmd_k);
-
- pte_k = pte_offset_kernel(pmd_k, address);
- if (!pte_present(*pte_k))
- goto no_context;
-
- addr = (address & PAGE_MASK);
- set_thread_fault_code(error_code);
- update_mmu_cache(NULL, addr, pte_k);
- set_thread_fault_code(0);
- return;
- }
-}
-
-/*======================================================================*
- * update_mmu_cache()
- *======================================================================*/
-#define TLB_MASK (NR_TLB_ENTRIES - 1)
-#define ITLB_END (unsigned long *)(ITLB_BASE + (NR_TLB_ENTRIES * 8))
-#define DTLB_END (unsigned long *)(DTLB_BASE + (NR_TLB_ENTRIES * 8))
-void update_mmu_cache(struct vm_area_struct *vma, unsigned long vaddr,
- pte_t *ptep)
-{
- volatile unsigned long *entry1, *entry2;
- unsigned long pte_data, flags;
- unsigned int *entry_dat;
- int inst = get_thread_fault_code() & ACE_INSTRUCTION;
- int i;
-
- /* Ptrace may call this routine. */
- if (vma && current->active_mm != vma->vm_mm)
- return;
-
- local_irq_save(flags);
-
- vaddr = (vaddr & PAGE_MASK) | get_asid();
-
- pte_data = pte_val(*ptep);
-
-#ifdef CONFIG_CHIP_OPSP
- entry1 = (unsigned long *)ITLB_BASE;
- for (i = 0; i < NR_TLB_ENTRIES; i++) {
- if (*entry1++ == vaddr) {
- set_tlb_data(entry1, pte_data);
- break;
- }
- entry1++;
- }
- entry2 = (unsigned long *)DTLB_BASE;
- for (i = 0; i < NR_TLB_ENTRIES; i++) {
- if (*entry2++ == vaddr) {
- set_tlb_data(entry2, pte_data);
- break;
- }
- entry2++;
- }
-#else
- /*
- * Update TLB entries
- * entry1: ITLB entry address
- * entry2: DTLB entry address
- */
- __asm__ __volatile__ (
- "seth %0, #high(%4) \n\t"
- "st %2, @(%5, %0) \n\t"
- "ldi %1, #1 \n\t"
- "st %1, @(%6, %0) \n\t"
- "add3 r4, %0, %7 \n\t"
- ".fillinsn \n"
- "1: \n\t"
- "ld %1, @(%6, %0) \n\t"
- "bnez %1, 1b \n\t"
- "ld %0, @r4+ \n\t"
- "ld %1, @r4 \n\t"
- "st %3, @+%0 \n\t"
- "st %3, @+%1 \n\t"
- : "=&r" (entry1), "=&r" (entry2)
- : "r" (vaddr), "r" (pte_data), "i" (MMU_REG_BASE),
- "i" (MSVA_offset), "i" (MTOP_offset), "i" (MIDXI_offset)
- : "r4", "memory"
- );
-#endif
-
- if ((!inst && entry2 >= DTLB_END) || (inst && entry1 >= ITLB_END))
- goto notfound;
-
-found:
- local_irq_restore(flags);
-
- return;
-
- /* Valid entry not found */
-notfound:
- /*
- * Update ITLB or DTLB entry
- * entry1: TLB entry address
- * entry2: TLB base address
- */
- if (!inst) {
- entry2 = (unsigned long *)DTLB_BASE;
- entry_dat = &tlb_entry_d;
- } else {
- entry2 = (unsigned long *)ITLB_BASE;
- entry_dat = &tlb_entry_i;
- }
- entry1 = entry2 + (((*entry_dat - 1) & TLB_MASK) << 1);
-
- for (i = 0 ; i < NR_TLB_ENTRIES ; i++) {
- if (!(entry1[1] & 2)) /* Valid bit check */
- break;
-
- if (entry1 != entry2)
- entry1 -= 2;
- else
- entry1 += TLB_MASK << 1;
- }
-
- if (i >= NR_TLB_ENTRIES) { /* Empty entry not found */
- entry1 = entry2 + (*entry_dat << 1);
- *entry_dat = (*entry_dat + 1) & TLB_MASK;
- }
- *entry1++ = vaddr; /* Set TLB tag */
- set_tlb_data(entry1, pte_data);
-
- goto found;
-}
-
-/*======================================================================*
- * flush_tlb_page() : flushes one page
- *======================================================================*/
-void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
-{
- if (vma->vm_mm && mm_context(vma->vm_mm) != NO_CONTEXT) {
- unsigned long flags;
-
- local_irq_save(flags);
- page &= PAGE_MASK;
- page |= (mm_context(vma->vm_mm) & MMU_CONTEXT_ASID_MASK);
- __flush_tlb_page(page);
- local_irq_restore(flags);
- }
-}
-
-/*======================================================================*
- * flush_tlb_range() : flushes a range of pages
- *======================================================================*/
-void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
- unsigned long end)
-{
- struct mm_struct *mm;
-
- mm = vma->vm_mm;
- if (mm_context(mm) != NO_CONTEXT) {
- unsigned long flags;
- int size;
-
- local_irq_save(flags);
- size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
- if (size > (NR_TLB_ENTRIES / 4)) { /* Too many TLB to flush */
- mm_context(mm) = NO_CONTEXT;
- if (mm == current->mm)
- activate_context(mm);
- } else {
- unsigned long asid;
-
- asid = mm_context(mm) & MMU_CONTEXT_ASID_MASK;
- start &= PAGE_MASK;
- end += (PAGE_SIZE - 1);
- end &= PAGE_MASK;
-
- start |= asid;
- end |= asid;
- while (start < end) {
- __flush_tlb_page(start);
- start += PAGE_SIZE;
- }
- }
- local_irq_restore(flags);
- }
-}
-
-/*======================================================================*
- * flush_tlb_mm() : flushes the specified mm context TLB's
- *======================================================================*/
-void local_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(mm) != NO_CONTEXT) {
- unsigned long flags;
-
- local_irq_save(flags);
- mm_context(mm) = NO_CONTEXT;
- if (mm == current->mm)
- activate_context(mm);
- local_irq_restore(flags);
- }
-}
-
-/*======================================================================*
- * flush_tlb_all() : flushes all processes TLBs
- *======================================================================*/
-void local_flush_tlb_all(void)
-{
- unsigned long flags;
-
- local_irq_save(flags);
- __flush_tlb_all();
- local_irq_restore(flags);
-}
-
-/*======================================================================*
- * init_mmu()
- *======================================================================*/
-void __init init_mmu(void)
-{
- tlb_entry_i = 0;
- tlb_entry_d = 0;
- mmu_context_cache = MMU_CONTEXT_FIRST_VERSION;
- set_asid(mmu_context_cache & MMU_CONTEXT_ASID_MASK);
- *(volatile unsigned long *)MPTB = (unsigned long)swapper_pg_dir;
-}
git.samba.org / sfrench / cifs-2.6.git / blobdiff