base/include/asm-i386/rtai_shm.h

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/*
 * Copyright (C) 1999-2003 Paolo Mantegazza <mantegazza@aero.polimi.it>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#ifndef _RTAI_ASM_I386_SHM_H
#define _RTAI_ASM_I386_SHM_H

#include <asm/pgtable.h>
#include <asm/io.h>
#include <asm/rtai_vectors.h>
#include <rtai_wrappers.h>

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
#define VMALLOC_VMADDR(x) ((unsigned long)(x))
#endif /* >= 2.6.0 */

#ifndef __KERNEL__

static inline long long rtai_shmrq(int srq, unsigned long args)
{
    long long retval;
    RTAI_DO_TRAP(RTAI_SYS_VECTOR, retval, srq, args);
    return retval;
}

#endif /* __KERNEL__ */

/* convert virtual user memory address to physical address */
/* (virt_to_phys only works for kmalloced kernel memory) */

static inline unsigned long uvirt_to_kva(pgd_t *pgd, unsigned long adr)
{
    unsigned long ret = 0UL;
    pmd_t *pmd;
    pte_t *ptep, pte;

    if(!pgd_none(*pgd)) {
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,11)
        pmd = pmd_offset(pgd, adr);
#else /* >= 2.6.11 */
        pmd = pmd_offset(pud_offset(pgd, adr), adr);
#endif /* < 2.6.11 */
        if (!pmd_none(*pmd)) {
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
            ptep = pte_offset(pmd, adr);
#else /* >= 2.6.0 */
            ptep = pte_offset_kernel(pmd, adr);
#endif /* < 2.6.0 */
            pte = *ptep;
            if(pte_present(pte)){
                ret = (unsigned long) page_address(pte_page(pte));
                ret |= (adr&(PAGE_SIZE-1));
            }
        }
    }
    return ret;
}

static inline unsigned long uvirt_to_bus(unsigned long adr)
{
    unsigned long kva, ret;

    kva = uvirt_to_kva(pgd_offset(current->mm, adr), adr);
    ret = virt_to_bus((void *)kva);

    return ret;
}

static inline unsigned long kvirt_to_bus(unsigned long adr)
{
    unsigned long va, kva, ret;

    va = VMALLOC_VMADDR(adr);
    kva = uvirt_to_kva(pgd_offset_k(va), va);
    ret = virt_to_bus((void *)kva);

    return ret;
}

static inline unsigned long kvirt_to_pa(unsigned long adr)
{
    unsigned long va, kva, ret;

    va = VMALLOC_VMADDR(adr);
    kva = uvirt_to_kva(pgd_offset_k(va), va);
    ret = __pa(kva);

    return ret;
}

#endif  /* !_RTAI_ASM_I386_SHM_H */

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