Subversion Repositories c0or1k

/*

 * ARMv7 specific functions

 *

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

 */

#include <macros.h>

#include <l4lib/exregs.h>

#include <fault.h>

#include INC_SUBARCH(mm.h)

#include INC_SUBARCH(exception.h)

/* Get simplified access permissions */

int pte_get_access_simple(pte_t pte)

{

        /* Place AP[2] and AP[1] in [1:0] positions and return */

        return (((pte >> PTE_AP2_BIT) & 1) << 1)

               | ((pte >> PTE_AP1_BIT) & 1);

}

int is_translation_fault(u32 fsr)

{

        return (fsr & FSR_FS_MASK) == ABORT_TRANSLATION_PAGE;

}

unsigned int vm_prot_flags(pte_t pte, u32 fsr)

{

        unsigned int pte_prot_flags = 0;

        /* Translation fault means no permissions */

        if (is_translation_fault(fsr))

                return VM_NONE;

        /* Check simplified permission bits */

        switch (pte_get_access_simple(pte)) {

        case AP_SIMPLE_USER_RW_KERN_RW:

                pte_prot_flags |= VM_WRITE;

        case AP_SIMPLE_USER_RO_KERN_RO:

                pte_prot_flags |= VM_READ;

                /* Also, check exec never bit */

                if (!(pte & (1 << PTE_XN_BIT)))

                        pte_prot_flags |= VM_EXEC;

                break;

        case AP_SIMPLE_USER_NONE_KERN_RW:

        case AP_SIMPLE_USER_NONE_KERN_RO:

        default:

                pte_prot_flags = VM_NONE;

                break;

        }

        return pte_prot_flags;

}

void set_generic_fault_params(struct fault_data *fault)

{

        fault->pte_flags = vm_prot_flags(fault->kdata->pte, fault->kdata->fsr);

        fault->reason = 0;

        /*

         * Prefetch fault denotes exec fault.

         */

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

                fault->reason |= VM_EXEC;

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

        } else {

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

                /* Write-not-read bit determines fault */

                if (fault->kdata->fsr & (1 << DFSR_WNR_BIT))

                        fault->reason |= VM_WRITE;

                else

                        fault->reason |= VM_READ;

        }

}