sanchayanmaity/xv6-cs450
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generalize async read to support write too

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This commit is contained in:
kaashoek 2006-08-06 20:28:15 +00:00
parent 366189214e
commit 8ec6530fee
3 changed files with 17 additions and 12 deletions
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4
bio.c
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@ -42,9 +42,9 @@ bread(uint dev, uint sector)
b = getblk();
acquire(&ide_lock);
c = ide_start_read(dev & 0xff, sector, b->data, 1);
c = ide_start_rw(dev & 0xff, sector, b->data, 1, 1);
sleep (c, &ide_lock);
ide_finish_read(c);
ide_finish(c);
release(&ide_lock);
return b;

4
defs.h
View file

@ -91,8 +91,8 @@ void fd_incref(struct fd *fd);
// ide.c
void ide_init(void);
void ide_intr(void);
void* ide_start_read(int diskno, uint secno, void *dst, uint nsecs);
int ide_finish_read(void *);
void* ide_start_rw(int diskno, uint secno, void *dst, uint nsecs, int read);
int ide_finish(void *);
// bio.c
struct buf;

21
ide.c
View file

@ -20,8 +20,9 @@
struct ide_request {
int diskno;
uint secno;
void *dst;
void *addr;
uint nsecs;
uint read;
};
struct ide_request request[NREQUEST];
int head, tail;
@ -93,20 +94,22 @@ ide_start_request (void)
if (head != tail) {
r = &request[tail];
ide_wait_ready(0);
outb(0x3f6, 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));
outb(0x1F7, 0x20); // CMD 0x20 means read sector
if (r->read) outb(0x1F7, 0x20); // read
else outb(0x1F7, 0x30); // write
}
}
void *
ide_start_read(int diskno, uint secno, void *dst, uint nsecs)
ide_start_rw(int diskno, uint secno, void *addr, uint nsecs, int read)
{
struct ide_request *r;
if(!holding(&ide_lock))
panic("ide_start_read: not holding ide_lock");
@ -118,9 +121,10 @@ ide_start_read(int diskno, uint secno, void *dst, uint nsecs)
r = &request[head];
r->secno = secno;
r->dst = dst;
r->addr = addr;
r->nsecs = nsecs;
r->diskno = diskno;
r->read = read;
head = (head + 1) % NREQUEST;
@ -130,7 +134,7 @@ ide_start_read(int diskno, uint secno, void *dst, uint nsecs)
}
int
ide_finish_read(void *c)
ide_finish(void *c)
{
int r = 0;
struct ide_request *req = (struct ide_request *) c;
@ -140,10 +144,11 @@ ide_finish_read(void *c)
if(!holding(&ide_lock))
panic("ide_start_read: not holding ide_lock");
for (; req->nsecs > 0; req->nsecs--, req->dst += 512) {
for (; req->nsecs > 0; req->nsecs--, req->addr += 512) {
if ((r = ide_wait_ready(1)) < 0)
break;
insl(0x1F0, req->dst, 512/4);
if (req->read) insl(0x1F0, req->addr, 512/4);
else outsl(0x1F0, req->addr, 512/4);
}
if ((head + 1) % NREQUEST == tail) {