- 根目录:
- arch
- parisc
- lib
- io.c
/*
* arch/parisc/lib/io.c
*
* Copyright (c) Matthew Wilcox 2001 for Hewlett-Packard
* Copyright (c) Randolph Chung 2001 <tausq@debian.org>
*
* IO accessing functions which shouldn't be inlined because they're too big
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <asm/io.h>
/* Copies a block of memory to a device in an efficient manner.
* Assumes the device can cope with 32-bit transfers. If it can't,
* don't use this function.
*/
void memcpy_toio(volatile void __iomem *dst, const void *src, int count)
{
if (((unsigned long)dst & 3) != ((unsigned long)src & 3))
goto bytecopy;
while ((unsigned long)dst & 3) {
writeb(*(char *)src, dst++);
src++;
count--;
}
while (count > 3) {
__raw_writel(*(u32 *)src, dst);
src += 4;
dst += 4;
count -= 4;
}
bytecopy:
while (count--) {
writeb(*(char *)src, dst++);
src++;
}
}
/*
** Copies a block of memory from a device in an efficient manner.
** Assumes the device can cope with 32-bit transfers. If it can't,
** don't use this function.
**
** CR16 counts on C3000 reading 256 bytes from Symbios 896 RAM:
** 27341/64 = 427 cyc per int
** 61311/128 = 478 cyc per short
** 122637/256 = 479 cyc per byte
** Ergo bus latencies dominant (not transfer size).
** Minimize total number of transfers at cost of CPU cycles.
** TODO: only look at src alignment and adjust the stores to dest.
*/
void memcpy_fromio(void *dst, const volatile void __iomem *src, int count)
{
/* first compare alignment of src/dst */
if ( (((unsigned long)dst ^ (unsigned long)src) & 1) || (count < 2) )
goto bytecopy;
if ( (((unsigned long)dst ^ (unsigned long)src) & 2) || (count < 4) )
goto shortcopy;
/* Then check for misaligned start address */
if ((unsigned long)src & 1) {
*(u8 *)dst = readb(src);
src++;
dst++;
count--;
if (count < 2) goto bytecopy;
}
if ((unsigned long)src & 2) {
*(u16 *)dst = __raw_readw(src);
src += 2;
dst += 2;
count -= 2;
}
while (count > 3) {
*(u32 *)dst = __raw_readl(src);
dst += 4;
src += 4;
count -= 4;
}
shortcopy:
while (count > 1) {
*(u16 *)dst = __raw_readw(src);
src += 2;
dst += 2;
count -= 2;
}
bytecopy:
while (count--) {
*(char *)dst = readb(src);
src++;
dst++;
}
}
/* Sets a block of memory on a device to a given value.
* Assumes the device can cope with 32-bit transfers. If it can't,
* don't use this function.
*/
void memset_io(volatile void __iomem *addr, unsigned char val, int count)
{
u32 val32 = (val << 24) | (val << 16) | (val << 8) | val;
while ((unsigned long)addr & 3) {
writeb(val, addr++);
count--;
}
while (count > 3) {
__raw_writel(val32, addr);
addr += 4;
count -= 4;
}
while (count--) {
writeb(val, addr++);
}
}
/*
* Read COUNT 8-bit bytes from port PORT into memory starting at
* SRC.
*/
void insb (unsigned long port, void *dst, unsigned long count)
{
unsigned char *p;
p = (unsigned char *)dst;
while (((unsigned long)p) & 0x3) {
if (!count)
return;
count--;
*p = inb(port);
p++;
}
while (count >= 4) {
unsigned int w;
count -= 4;
w = inb(port) << 24;
w |= inb(port) << 16;
w |= inb(port) << 8;
w |= inb(port);
*(unsigned int *) p = w;
p += 4;
}
while (count) {
--count;
*p = inb(port);
p++;
}
}
/*
* Read COUNT 16-bit words from port PORT into memory starting at
* SRC. SRC must be at least short aligned. This is used by the
* IDE driver to read disk sectors. Performance is important, but
* the interfaces seems to be slow: just using the inlined version
* of the inw() breaks things.
*/
void insw (unsigned long port, void *dst, unsigned long count)
{
unsigned int l = 0, l2;
unsigned char *p;
p = (unsigned char *)dst;
if (!count)
return;
switch (((unsigned long)p) & 0x3)
{
case 0x00: /* Buffer 32-bit aligned */
while (count>=2) {
count -= 2;
l = cpu_to_le16(inw(port)) << 16;
l |= cpu_to_le16(inw(port));
*(unsigned int *)p = l;
p += 4;
}
if (count) {
*(unsigned short *)p = cpu_to_le16(inw(port));
}
break;
case 0x02: /* Buffer 16-bit aligned */
*(unsigned short *)p = cpu_to_le16(inw(port));
p += 2;
count--;
while (count>=2) {
count -= 2;
l = cpu_to_le16(inw(port)) << 16;
l |= cpu_to_le16(inw(port));
*(unsigned int *)p = l;
p += 4;
}
if (count) {
*(unsigned short *)p = cpu_to_le16(inw(port));
}
break;
case 0x01: /* Buffer 8-bit aligned */
case 0x03:
/* I don't bother with 32bit transfers
* in this case, 16bit will have to do -- DE */
--count;
l = cpu_to_le16(inw(port));
*p = l >> 8;
p++;
while (count--)
{
l2 = cpu_to_le16(inw(port));
*(unsigned short *)p = (l & 0xff) << 8 | (l2 >> 8);
p += 2;
l = l2;
}
*p = l & 0xff;
break;
}
}
/*
* Read COUNT 32-bit words from port PORT into memory starting at
* SRC. Now works with any alignment in SRC. Performance is important,
* but the interfaces seems to be slow: just using the inlined version
* of the inl() breaks things.
*/
void insl (unsigned long port, void *dst, unsigned long count)
{
unsigned int l = 0, l2;
unsigned char *p;
p = (unsigned char *)dst;
if (!count)
return;
switch (((unsigned long) dst) & 0x3)
{
case 0x00: /* Buffer 32-bit aligned */
while (count--)
{
*(unsigned int *)p = cpu_to_le32(inl(port));
p += 4;
}
break;
case 0x02: /* Buffer 16-bit aligned */
--count;
l = cpu_to_le32(inl(port));
*(unsigned short *)p = l >> 16;
p += 2;
while (count--)
{
l2 = cpu_to_le32(inl(port));
*(unsigned int *)p = (l & 0xffff) << 16 | (l2 >> 16);
p += 4;
l = l2;
}
*(unsigned short *)p = l & 0xffff;
break;
case 0x01: /* Buffer 8-bit aligned */
--count;
l = cpu_to_le32(inl(port));
*(unsigned char *)p = l >> 24;
p++;
*(unsigned short *)p = (l >> 8) & 0xffff;
p += 2;
while (count--)
{
l2 = cpu_to_le32(inl(port));
*(unsigned int *)p = (l & 0xff) << 24 | (l2 >> 8);
p += 4;
l = l2;
}
*p = l & 0xff;
break;
case 0x03: /* Buffer 8-bit aligned */
--count;
l = cpu_to_le32(inl(port));
*p = l >> 24;
p++;
while (count--)
{
l2 = cpu_to_le32(inl(port));
*(unsigned int *)p = (l & 0xffffff) << 8 | l2 >> 24;
p += 4;
l = l2;
}
*(unsigned short *)p = (l >> 8) & 0xffff;
p += 2;
*p = l & 0xff;
break;
}
}
/*
* Like insb but in the opposite direction.
* Don't worry as much about doing aligned memory transfers:
* doing byte reads the "slow" way isn't nearly as slow as
* doing byte writes the slow way (no r-m-w cycle).
*/
void outsb(unsigned long port, const void * src, unsigned long count)
{
const unsigned char *p;
p = (const unsigned char *)src;
while (count) {
count--;
outb(*p, port);
p++;
}
}
/*
* Like insw but in the opposite direction. This is used by the IDE
* driver to write disk sectors. Performance is important, but the
* interfaces seems to be slow: just using the inlined version of the
* outw() breaks things.
*/
void outsw (unsigned long port, const void *src, unsigned long count)
{
unsigned int l = 0, l2;
const unsigned char *p;
p = (const unsigned char *)src;
if (!count)
return;
switch (((unsigned long)p) & 0x3)
{
case 0x00: /* Buffer 32-bit aligned */
while (count>=2) {
count -= 2;
l = *(unsigned int *)p;
p += 4;
outw(le16_to_cpu(l >> 16), port);
outw(le16_to_cpu(l & 0xffff), port);
}
if (count) {
outw(le16_to_cpu(*(unsigned short*)p), port);
}
break;
case 0x02: /* Buffer 16-bit aligned */
outw(le16_to_cpu(*(unsigned short*)p), port);
p += 2;
count--;
while (count>=2) {
count -= 2;
l = *(unsigned int *)p;
p += 4;
outw(le16_to_cpu(l >> 16), port);
outw(le16_to_cpu(l & 0xffff), port);
}
if (count) {
outw(le16_to_cpu(*(unsigned short *)p), port);
}
break;
case 0x01: /* Buffer 8-bit aligned */
/* I don't bother with 32bit transfers
* in this case, 16bit will have to do -- DE */
l = *p << 8;
p++;
count--;
while (count)
{
count--;
l2 = *(unsigned short *)p;
p += 2;
outw(le16_to_cpu(l | l2 >> 8), port);
l = l2 << 8;
}
l2 = *(unsigned char *)p;
outw (le16_to_cpu(l | l2>>8), port);
break;
}
}
/*
* Like insl but in the opposite direction. This is used by the IDE
* driver to write disk sectors. Works with any alignment in SRC.
* Performance is important, but the interfaces seems to be slow:
* just using the inlined version of the outl() breaks things.
*/
void outsl (unsigned long port, const void *src, unsigned long count)
{
unsigned int l = 0, l2;
const unsigned char *p;
p = (const unsigned char *)src;
if (!count)
return;
switch (((unsigned long)p) & 0x3)
{
case 0x00: /* Buffer 32-bit aligned */
while (count--)
{
outl(le32_to_cpu(*(unsigned int *)p), port);
p += 4;
}
break;
case 0x02: /* Buffer 16-bit aligned */
--count;
l = *(unsigned short *)p;
p += 2;
while (count--)
{
l2 = *(unsigned int *)p;
p += 4;
outl (le32_to_cpu(l << 16 | l2 >> 16), port);
l = l2;
}
l2 = *(unsigned short *)p;
outl (le32_to_cpu(l << 16 | l2), port);
break;
case 0x01: /* Buffer 8-bit aligned */
--count;
l = *p << 24;
p++;
l |= *(unsigned short *)p << 8;
p += 2;
while (count--)
{
l2 = *(unsigned int *)p;
p += 4;
outl (le32_to_cpu(l | l2 >> 24), port);
l = l2 << 8;
}
l2 = *p;
outl (le32_to_cpu(l | l2), port);
break;
case 0x03: /* Buffer 8-bit aligned */
--count;
l = *p << 24;
p++;
while (count--)
{
l2 = *(unsigned int *)p;
p += 4;
outl (le32_to_cpu(l | l2 >> 8), port);
l = l2 << 24;
}
l2 = *(unsigned short *)p << 16;
p += 2;
l2 |= *p;
outl (le32_to_cpu(l | l2), port);
break;
}
}
EXPORT_SYMBOL(insb);
EXPORT_SYMBOL(insw);
EXPORT_SYMBOL(insl);
EXPORT_SYMBOL(outsb);
EXPORT_SYMBOL(outsw);
EXPORT_SYMBOL(outsl);