xv6/ide.c
rtm 46bbd72f3e no more recursive locks
wakeup1() assumes you hold proc_table_lock
sleep(chan, lock) provides atomic sleep-and-release to wait for condition
ugly code in swtch/scheduler to implement new sleep
fix lots of bugs in pipes, wait, and exit
fix bugs if timer interrupt goes off in schedule()
console locks per line, not per byte
2006-07-15 12:03:57 +00:00

175 lines
3.1 KiB
C

/*
* Minimal PIO-based (non-interrupt-driven) IDE driver code.
* For information about what all this IDE/ATA magic means,
* see the materials available on the class references page.
*/
#include "types.h"
#include "param.h"
#include "mmu.h"
#include "proc.h"
#include "defs.h"
#include "x86.h"
#define IDE_BSY 0x80
#define IDE_DRDY 0x40
#define IDE_DF 0x20
#define IDE_ERR 0x01
struct ide_request {
uint32_t secno;
void *dst;
unsigned nsecs;
};
struct ide_request request[NREQUEST];
int head, tail;
static int diskno = 0;
int disk_channel;
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)
{
cprintf("ide_init: enable IRQ 14\n");
irq_setmask_8259A(irq_mask_8259A & ~(1<<14));
ide_wait_ready(0);
}
void
ide_intr(void)
{
cprintf("ide_intr\n");
wakeup(&request[tail]);
}
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));
cprintf("Device 1 presence: %d\n", (x < 1000));
return (x < 1000);
}
void
ide_set_disk(int d)
{
if (d != 0 && d != 1)
panic("bad disk number");
diskno = d;
}
void
ide_start_request (void)
{
struct ide_request *r;
if (head == tail) {
r = &request[tail];
ide_wait_ready(0);
outb(0x3f6, 0);
outb(0x1F2, r->nsecs);
outb(0x1F3, r->secno & 0xFF);
outb(0x1F4, (r->secno >> 8) & 0xFF);
outb(0x1F5, (r->secno >> 16) & 0xFF);
outb(0x1F6, 0xE0 | ((diskno&1)<<4) | ((r->secno>>24)&0x0F));
outb(0x1F7, 0x20); // CMD 0x20 means read sector
}
}
void *
ide_start_read(uint32_t secno, void *dst, unsigned nsecs)
{
struct ide_request *r;
if(nsecs > 256)
panic("ide_start_read: nsecs too large");
while ((head + 1) % NREQUEST == tail)
sleep (&disk_channel, 0);
r = &request[head];
r->secno = secno;
r->dst = dst;
r->nsecs = nsecs;
ide_start_request();
head = (head + 1) % NREQUEST;
return r;
}
int
ide_finish_read(void *c)
{
int r = 0;
struct ide_request *req = (struct ide_request *) c;
for (; req->nsecs > 0; req->nsecs--, req->dst += 512) {
if ((r = ide_wait_ready(1)) < 0)
break;
insl(0x1F0, req->dst, 512/4);
}
if ((head + 1) % NREQUEST == tail) {
wakeup(&disk_channel);
}
tail = (tail + 1) % NREQUEST;
ide_start_request();
return 0;
}
int
ide_write(uint32_t secno, const void *src, unsigned 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;
}