xv6/ide.c
kaashoek 7abf49d2f2 remove duplication
don't use the same name for two different pieces of code
2006-09-03 15:39:29 +00:00

177 lines
3.1 KiB
C

/*
* Simple PIO-based (non-DMA) IDE driver code.
*/
#include "types.h"
#include "param.h"
#include "mmu.h"
#include "proc.h"
#include "defs.h"
#include "x86.h"
#include "traps.h"
#include "spinlock.h"
#define IDE_BSY 0x80
#define IDE_DRDY 0x40
#define IDE_DF 0x20
#define IDE_ERR 0x01
struct ide_request {
int diskno;
uint secno;
void *addr;
uint nsecs;
uint read;
};
struct ide_request request[NREQUEST];
int head, tail;
struct spinlock ide_lock;
int disk_1_present;
int disk_channel;
int ide_probe_disk1(void);
static int
ide_wait_ready(int check_error)
{
int r;
while (((r = inb(0x1F7)) & (IDE_BSY|IDE_DRDY)) != IDE_DRDY)
/* do nothing */;
if (check_error && (r & (IDE_DF|IDE_ERR)) != 0)
return -1;
return 0;
}
void
ide_init(void)
{
initlock(&ide_lock, "ide");
ioapic_enable (IRQ_IDE, ncpu - 1);
ide_wait_ready(0);
disk_1_present = ide_probe_disk1();
}
void
ide_intr(void)
{
acquire(&ide_lock);
wakeup(&request[tail]);
release(&ide_lock);
}
int
ide_probe_disk1(void)
{
int r, x;
// wait for Device 0 to be ready
ide_wait_ready(0);
// switch to Device 1
outb(0x1F6, 0xE0 | (1<<4));
// check for Device 1 to be ready for a while
for (x = 0; x < 1000 && (r = inb(0x1F7)) == 0; x++)
/* do nothing */;
// switch back to Device 0
outb(0x1F6, 0xE0 | (0<<4));
return (x < 1000);
}
void
ide_start_request (void)
{
struct ide_request *r;
if (head != tail) {
r = &request[tail];
ide_wait_ready(0);
outb(0x3f6, 0); // generate interrupt
outb(0x1F2, r->nsecs);
outb(0x1F3, r->secno & 0xFF);
outb(0x1F4, (r->secno >> 8) & 0xFF);
outb(0x1F5, (r->secno >> 16) & 0xFF);
outb(0x1F6, 0xE0 | ((r->diskno&1)<<4) | ((r->secno>>24)&0x0F));
if (r->read) outb(0x1F7, 0x20); // read
else {
outb(0x1F7, 0x30); // write
outsl(0x1F0, r->addr, 512/4);
}
}
}
void *
ide_start_rw(int diskno, uint secno, void *addr, uint nsecs, int read)
{
struct ide_request *r;
if(diskno && !disk_1_present)
panic("ide disk 1 not present");
while ((head + 1) % NREQUEST == tail)
sleep (&disk_channel, &ide_lock);
r = &request[head];
r->secno = secno;
r->addr = addr;
r->nsecs = nsecs;
r->diskno = diskno;
r->read = read;
head = (head + 1) % NREQUEST;
ide_start_request();
return r;
}
int
ide_finish(void *c)
{
int r;
struct ide_request *req = (struct ide_request *) c;
if (req->read) {
if ((r = ide_wait_ready(1)) >= 0)
insl(0x1F0, req->addr, 512/4);
}
if ((head + 1) % NREQUEST == tail) {
wakeup(&disk_channel);
}
tail = (tail + 1) % NREQUEST;
ide_start_request();
return 0;
}
int
ide_write(int diskno, uint secno, const void *src, uint nsecs)
{
int r;
if(nsecs > 256)
panic("ide_write");
ide_wait_ready(0);
outb(0x1F2, nsecs);
outb(0x1F3, secno & 0xFF);
outb(0x1F4, (secno >> 8) & 0xFF);
outb(0x1F5, (secno >> 16) & 0xFF);
outb(0x1F6, 0xE0 | ((diskno&1)<<4) | ((secno>>24)&0x0F));
outb(0x1F7, 0x30); // CMD 0x30 means write sector
for (; nsecs > 0; nsecs--, src += 512) {
if ((r = ide_wait_ready(1)) < 0)
return r;
outsl(0x1F0, src, 512/4);
}
return 0;
}