static struct SectorCache *
cache_fetch(uint_32 sector) {
//printk("enter cache_fetch\n");
struct SectorCache *ptr = &cache[sector % NR_SEC_CACHE];
if (ptr->used == TRUE && ptr->sector == sector) {
//printk("hit\n");
/* cache hit, do nothing */
} else {
//printk("miss\n");
if (ptr->used == TRUE && ptr->dirty == TRUE) {
/* write back */
ide_prepare(ptr->sector);
do_write(&ptr->content);
}
/* issue a read command */
ide_prepare(sector);
issue_read();
do_read(&ptr->content);
ptr->used = TRUE;
ptr->sector = sector;
ptr->dirty = FALSE;
}
return ptr;
}
void
disk_do_write(void *buf, uint32_t sector) {
int i;
ide_prepare(sector);
issue_write();
for (i = 0; i < 512 / sizeof(uint32_t); i ++) {
out_long(IDE_PORT_BASE, *(((uint32_t*)buf) + i));
}
}
void
disk_do_read(void *buf, uint32_t sector) {
int i;
ide_prepare(sector);
issue_read();
waitdisk();
for (i = 0; i < 512 / sizeof(uint32_t); i ++) {
*(((uint32_t*)buf) + i) = in_long(IDE_PORT_BASE);
}
}
void
ide_driver_thread(void) {
static struct Message m;
while (TRUE) {
receive(ANY, &m);
if (m.src == MSG_HARD_INTR) {
if (m.type == IDE_WRITEBACK) {
int i;
for (i = 0; i < NR_SEC_CACHE; i ++) {
if (cache[i].dirty == TRUE) {
ide_prepare(cache[i].sector);
do_write(&cache[i].content);
cache[i].dirty = FALSE;
}
}
} else {
panic("IDE interrupt is leaking");
}
} else if (m.type == DEV_READ) {
//printk("IDE driver receive request!\n");
//printk("rr\n");
uint_32 i, data;
struct PCB *pcb = fetch_pcb(m.src);
//printk("length = %d\n", m.dev_io.length);
for (i = 0; i < m.dev_io.length; i ++) {
//printk("%d\n", i);
data = read_byte(m.dev_io.offset + i);
//printk("after data\n");
copy_from_kernel(pcb, m.dev_io.buf + i, &data, 1);
}
m.type = -1;
m.int_msg.p1 = i;
//printk("Almost Finished!\n");
send(m.src, &m);
//printk("ss\n");
} else if (m.type == DEV_WRITE) {
uint_32 i, data;
struct PCB *pcb = fetch_pcb(m.src);
for (i = 0; i < m.dev_io.length; i ++) {
copy_to_kernel(pcb, &data, m.dev_io.buf + i, 1);
write_byte(m.dev_io.offset + i, data);
}
m.type = -1;
m.int_msg.p1 = i;
send(m.src, &m);
}
}
}
