2 * linux/arch/cris/mm/fault.c
4 * Low level bus fault handler
7 * Copyright (C) 2000, 2001 Axis Communications AB
14 #include <asm/uaccess.h>
15 #include <asm/pgtable.h>
16 #include <asm/arch/svinto.h>
18 /* debug of low-level TLB reload */
27 extern volatile pgd_t *current_pgd;
29 extern const struct exception_table_entry
30 *search_exception_tables(unsigned long addr);
32 asmlinkage void do_page_fault(unsigned long address, struct pt_regs *regs,
33 int protection, int writeaccess);
35 /* fast TLB-fill fault handler
36 * this is called from entry.S with interrupts disabled
40 handle_mmu_bus_fault(struct pt_regs *regs)
49 pgd_t* pgd = (pgd_t*)current_pgd;
52 int miss, we, writeac;
53 unsigned long address;
58 address = cause & PAGE_MASK; /* get faulting address */
59 select = *R_TLB_SELECT;
62 page_id = IO_EXTRACT(R_MMU_CAUSE, page_id, cause);
63 acc = IO_EXTRACT(R_MMU_CAUSE, acc_excp, cause);
64 inv = IO_EXTRACT(R_MMU_CAUSE, inv_excp, cause);
65 index = IO_EXTRACT(R_TLB_SELECT, index, select);
67 miss = IO_EXTRACT(R_MMU_CAUSE, miss_excp, cause);
68 we = IO_EXTRACT(R_MMU_CAUSE, we_excp, cause);
69 writeac = IO_EXTRACT(R_MMU_CAUSE, wr_rd, cause);
71 D(printk("bus_fault from IRP 0x%lx: addr 0x%lx, miss %d, inv %d, we %d, acc %d, dx %d pid %d\n",
72 regs->irp, address, miss, inv, we, acc, index, page_id));
74 /* leave it to the MM system fault handler */
76 do_page_fault(address, regs, 0, writeac);
78 do_page_fault(address, regs, 1, we);
80 /* Reload TLB with new entry to avoid an extra miss exception.
81 * do_page_fault may have flushed the TLB so we have to restore
84 local_save_flags(flags);
86 pmd = (pmd_t *)(pgd + pgd_index(address));
89 pte = *pte_offset_kernel(pmd, address);
90 if (!pte_present(pte))
92 *R_TLB_SELECT = select;
94 *R_TLB_LO = pte_val(pte);
95 local_irq_restore(flags);
98 /* Called from arch/cris/mm/fault.c to find fixup code. */
100 find_fixup_code(struct pt_regs *regs)
102 const struct exception_table_entry *fixup;
104 if ((fixup = search_exception_tables(regs->irp)) != 0) {
105 /* Adjust the instruction pointer in the stackframe. */
106 regs->irp = fixup->fixup;
109 * Don't return by restoring the CPU state, so switch
112 regs->frametype = CRIS_FRAME_NORMAL;