xv6/ide.c
kaashoek f70172129c run without lapic and ioapic, if they are not present
if no lapic available, use 8253pit for clock
now xv6 runs both on qemu (uniprocessor) and bochs (uniprocessor and MP)
2006-09-07 01:37:58 +00:00

181 lines
3.2 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
#define IDE_CMD_READ 0x20
#define IDE_CMD_WRITE 0x30
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)
;
if(check_error && (r & (IDE_DF|IDE_ERR)) != 0)
return -1;
return 0;
}
void
ide_init(void)
{
initlock(&ide_lock, "ide");
irq_setmask_8259A(irq_mask_8259A & ~(1 << IRQ_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++)
;
// 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, IDE_CMD_READ);
else {
outb(0x1F7, IDE_CMD_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;
}