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/* $Id: io.c,v 1.4 1999/08/18 23:37:46 ralf Exp $
*
* 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);
}
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