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/*

 * ARMv5 specific functions

 *

 * Copyright (C) 2008 - 2010 B Labs Ltd.

 */

#include <task.h>

#include <vm_area.h>

#include <l4lib/exregs.h>

#include __INC_ARCH(mm.h)

/* Extracts generic protection flags from architecture-specific pte */

unsigned int vm_prot_flags(pte_t pte)

{

        unsigned int vm_prot_flags = 0;

        unsigned int rw_flags = __MAP_USR_RW & PTE_PROT_MASK;

        unsigned int ro_flags = __MAP_USR_RO & PTE_PROT_MASK;

        /* Clear non-protection flags */

        pte &= PTE_PROT_MASK;

        if (pte == ro_flags)

                vm_prot_flags = VM_READ | VM_EXEC;

        else if (pte == rw_flags)

                vm_prot_flags = VM_READ | VM_WRITE | VM_EXEC;

        else

                vm_prot_flags = VM_NONE;

        return vm_prot_flags;

}

/*

 * PTE STATES:

 * PTE type field: 00 (Translation fault)

 * PTE type field correct, AP bits: None (Read or Write access fault)

 * PTE type field correct, AP bits: RO (Write access fault)

 */

/*

 * Extracts arch-specific fault parameters

 * and puts them into generic format

 */

void set_generic_fault_params(struct fault_data *fault)

{

        unsigned int prot_flags = vm_prot_flags(fault->kdata->pte);

        fault->reason = 0;

        fault->pte_flags = prot_flags;

        if (is_prefetch_abort(fault->kdata->fsr)) {

                fault->reason |= VM_READ;

                fault->address = fault->kdata->faulty_pc;

        } else {

                fault->address = fault->kdata->far;

                /* Always assume read fault first */

                if (prot_flags & VM_NONE)

                        fault->reason |= VM_READ;

                else if (prot_flags & VM_READ)

                        fault->reason |= VM_WRITE;

                else

                        BUG();

        }

        arch_print_fault_params(fault);

}