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/*
* 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;
}
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