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/*

 * This file is subject to the terms and conditions of the GNU General Public

 * License.  See the file "COPYING" in the main directory of this archive

 * for more details.

 *

 * Low level I/O functions for SNI.

 */

#include <linux/string.h>

#include <linux/spinlock.h>

#include <asm/addrspace.h>

#include <asm/system.h>

#include <asm/sni.h>

/*

 * Urgs...  We only can see a 16mb window of the 4gb EISA address space

 * at PCIMT_EISA_BASE.  Maladia segmentitis ...

 *

 * To avoid locking and all the related headacke we implement this such

 * that accessing the bus address space nests, so we're treating this

 * correctly even for interrupts.  This is going to suck seriously for

 * the SMP members of the RM family.

 *

 * Making things worse the PCIMT_CSMAPISA register resides on the X bus with

 * it's unbeatable 1.4 mb/s transfer rate.

 */

static inline void eisa_map(unsigned long address)

{

        unsigned char upper;

        upper = address >> 24;

        *(volatile unsigned char *)PCIMT_CSMAPISA = ~upper;

}

#define save_eisa_map()                                                 \

        (*(volatile unsigned char *)PCIMT_CSMAPISA)

#define restore_eisa_map(val)                                           \

        do { (*(volatile unsigned char *)PCIMT_CSMAPISA) = val; } while(0)

static unsigned char sni_readb(unsigned long addr)

{

        unsigned char res;

        unsigned int save_map;

        save_map = save_eisa_map();

        eisa_map(addr);

        addr &= 0xffffff;

        res = *(volatile unsigned char *) (PCIMT_EISA_BASE + addr);

        restore_eisa_map(save_map);

        return res;

}

static unsigned short sni_readw(unsigned long addr)

{

        unsigned short res;

        unsigned int save_map;

        save_map = save_eisa_map();

        eisa_map(addr);

        addr &= 0xffffff;

        res = *(volatile unsigned char *) (PCIMT_EISA_BASE + addr);

        restore_eisa_map(save_map);

        return res;

}

static unsigned int sni_readl(unsigned long addr)

{

        unsigned int res;

        unsigned int save_map;

        save_map = save_eisa_map();

        eisa_map(addr);

        addr &= 0xffffff;

        res = *(volatile unsigned char *) (PCIMT_EISA_BASE + addr);

        restore_eisa_map(save_map);

        return res;

}

static void sni_writeb(unsigned char val, unsigned long addr)

{

        unsigned int save_map;

        save_map = save_eisa_map();

        eisa_map(addr);

        addr &= 0xffffff;

        *(volatile unsigned char *) (PCIMT_EISA_BASE + addr) = val;

        restore_eisa_map(save_map);

}

static void sni_writew(unsigned short val, unsigned long addr)

{

        unsigned int save_map;

        save_map = save_eisa_map();

        eisa_map(addr);

        addr &= 0xffffff;

        *(volatile unsigned char *) (PCIMT_EISA_BASE + addr) = val;

        restore_eisa_map(save_map);

}

static void sni_writel(unsigned int val, unsigned long addr)

{

        unsigned int save_map;

        save_map = save_eisa_map();

        eisa_map(addr);

        addr &= 0xffffff;

        *(volatile unsigned char *) (PCIMT_EISA_BASE + addr) = val;

        restore_eisa_map(save_map);

}

static void sni_memset_io(unsigned long addr, int val, unsigned long len)

{

        unsigned long waddr;

        unsigned int save_map;

        save_map = save_eisa_map();

        waddr = PCIMT_EISA_BASE | (addr & 0xffffff);

        while(len) {

                unsigned long fraglen;

                fraglen = (~addr + 1) & 0xffffff;

                fraglen = (fraglen < len) ? fraglen : len;

                eisa_map(addr);

                memset((char *)waddr, val, fraglen);

                addr += fraglen;

                waddr = waddr + fraglen - 0x1000000;

                len -= fraglen;

        }

        restore_eisa_map(save_map);

}

static void sni_memcpy_fromio(unsigned long to, unsigned long from, unsigned long len)

{

        unsigned long waddr;

        unsigned int save_map;

        save_map = save_eisa_map();

        waddr = PCIMT_EISA_BASE | (from & 0xffffff);

        while(len) {

                unsigned long fraglen;

                fraglen = (~from + 1) & 0xffffff;

                fraglen = (fraglen < len) ? fraglen : len;

                eisa_map(from);

                memcpy((void *)to, (void *)waddr, fraglen);

                to += fraglen;

                from += fraglen;

                waddr = waddr + fraglen - 0x1000000;

                len -= fraglen;

        }

        restore_eisa_map(save_map);

}

static void sni_memcpy_toio(unsigned long to, unsigned long from, unsigned long len)

{

        unsigned long waddr;

        unsigned int save_map;

        save_map = save_eisa_map();

        waddr = PCIMT_EISA_BASE | (to & 0xffffff);

        while(len) {

                unsigned long fraglen;

                fraglen = (~to + 1) & 0xffffff;

                fraglen = (fraglen < len) ? fraglen : len;

                eisa_map(to);

                memcpy((char *)to + PCIMT_EISA_BASE, (void *)from, fraglen);

                to += fraglen;

                from += fraglen;

                waddr = waddr + fraglen - 0x1000000;

                len -= fraglen;

        }

        restore_eisa_map(save_map);

}