static void do_request(void)
{
int i, r;
if (sorting)
return;
if (!this_request) {
do_hd = NULL;
return;
}
if (this_request->cmd == WIN_WRITE) {
hd_out(this_request->hd, this_request->nsector, this_request->sector,
this_request->head, this_request->cyl, this_request->cmd, &write_intr);
for (i = 0; i < 3000 && !(r = inb_p(HD_STATUS) & DRQ_STAT); i++)
/* nothing */;
if (!r) {
reset_hd(this_request->hd);
return;
}
port_write(HD_DATA, this_request->bh->b_data + 512*(this_request->nsector & 1), 256);
} else if (this_request->cmd == WIN_READ) {
hd_out(this_request->hd, this_request->nsector, this_request->sector,
this_request->head, this_request->cyl, this_request->cmd, &read_intr);
} else
panic("unknow hd-command");
}
void do_hd_request(void)
{
int i,r;
unsigned int block,dev;
unsigned int sec,head,cyl;
unsigned int nsect;
INIT_REQUEST;
dev = MINOR(CURRENT->dev);
block = CURRENT->sector;
if (dev >= (NR_HD<<6) || block+2 > hd[dev].nr_sects) {
end_request(0);
goto repeat;
}
block += hd[dev].start_sect;
dev >>= 6;
sec = block % hd_info[dev].sect;
block /= hd_info[dev].sect;
head = block % hd_info[dev].head;
cyl = block / hd_info[dev].head;
sec++;
nsect = CURRENT->nr_sectors;
if (reset) {
recalibrate = 1;
reset_hd();
return;
}
if (recalibrate) {
recalibrate = 0;
hd_out(dev,hd_info[CURRENT_DEV].sect,0,0,0,
WIN_RESTORE,&recal_intr);
if (reset)
goto repeat;
return;
}
if (CURRENT->cmd == WRITE) {
hd_out(dev,nsect,sec,head,cyl,WIN_WRITE,&write_intr);
if (reset)
goto repeat;
for(i=0 ; i<10000 && !(r=inb_p(HD_STATUS)&DRQ_STAT) ; i++)
/* nothing */ ;
if (!r) {
bad_rw_intr();
goto repeat;
}
port_write(HD_DATA,CURRENT->buffer,256);
} else if (CURRENT->cmd == READ) {
hd_out(dev,nsect,sec,head,cyl,WIN_READ,&read_intr);
if (reset)
goto repeat;
} else
panic("unknown hd-command");
}
// 处理请求队列里面所有请求
void do_hd_request(void)
{
int i,r = 0;
unsigned int block,dev;
unsigned int sec,head,cyl;
unsigned int nsect;
INIT_REQUEST;
dev = MINOR(CURRENT->dev);
block = CURRENT->sector;
if (dev >= 5*NR_HD || block+2 > hd[dev].nr_sects) {
end_request(0);
goto repeat;
}
block += hd[dev].start_sect;
dev /= 5;
__asm__("divl %4":"=a" (block),"=d" (sec):"0" (block),"1" (0),
"r" (hd_info[dev].sect));
__asm__("divl %4":"=a" (cyl),"=d" (head):"0" (block),"1" (0),
"r" (hd_info[dev].head));
sec++;
nsect = CURRENT->nr_sectors;
if (reset) {
reset = 0;
recalibrate = 1;
reset_hd(CURRENT_DEV);
return;
}
if (recalibrate) {
recalibrate = 0;
hd_out(dev,hd_info[CURRENT_DEV].sect,0,0,0,
WIN_RESTORE,&recal_intr);
return;
}
if (CURRENT->cmd == WRITE) {
hd_out(dev,nsect,sec,head,cyl,WIN_WRITE,&write_intr);
for(i=0 ; i<3000 && !(r=inb_p(HD_STATUS)&DRQ_STAT) ; i++)
/* nothing */ ;
if (!r) {
bad_rw_intr();
goto repeat;
}
port_write(HD_DATA,CURRENT->buffer,256);
} else if (CURRENT->cmd == READ) {
// 设置回调函数 read_intr 直接返回
hd_out(dev,nsect,sec,head,cyl,WIN_READ,&read_intr);
} else
panic("unknown hd-command");
}
/*
往硬盘控制器发送命令让它开始读盘，然后中断发生，再开始读数据
*/
void do_hd_request(void)
{
// block 是 2 个 sector
// dev 是给hd controller用的设备号，
int i,r;
unsigned int block,dev;
unsigned int sec,head,cyl;
unsigned int nsect;
// INIT_REQUEST;
dev = MINOR(CURRENT->dev);
block = CURRENT->sector;
dev /= 5;
__asm__("divl %4":"=a" (block),"=d" (sec):"0" (block),"1" (0),
"r" (hd_info[dev].sect));
__asm__("divl %4":"=a" (cyl),"=d" (head):"0" (block),"1" (0),
"r" (hd_info[dev].head));
sec++;
nsect = CURRENT->nr_sectors;
if (CURRENT->cmd == READ) {
hd_out(dev,nsect,sec,head,cyl,WIN_READ,&read_intr);
}
}
static int do_special_op(struct hd_i_struct *disk, struct request *req)
{
if (disk->recalibrate) {
disk->recalibrate = 0;
hd_out(disk,disk->sect,0,0,0,WIN_RESTORE,&recal_intr);
return reset;
}
if (disk->head > 16) {
printk ("%s: cannot handle device with more than 16 heads - giving up\n", req->rq_disk->disk_name);
end_request(req, 0);
}
disk->special_op = 0;
return 1;
}
static void reset_hd(void)
{
static int i;
repeat:
if (reset) {
reset = 0;
i = -1;
reset_controller();
} else if (win_result()) {
bad_rw_intr();
if (reset)
goto repeat;
}
i++;
if (i < NR_HD) {
hd_out(i,hd_info[i].sect,hd_info[i].sect,hd_info[i].head-1,
hd_info[i].cyl,WIN_SPECIFY,&reset_hd);
} else
do_hd_request();
}
static void reset_hd(void)
{
static int i;
repeat:
if (reset) {
reset = 0;
i = -1;
reset_controller();
} else {
check_status();
if (reset)
goto repeat;
}
if (++i < NR_HD) {
struct hd_i_struct *disk = &hd_info[i];
disk->special_op = disk->recalibrate = 1;
hd_out(disk,disk->sect,disk->sect,disk->head-1,
disk->cyl,WIN_SPECIFY,&reset_hd);
if (reset)
goto repeat;
} else
hd_request();
}
/*
* The driver enables interrupts as much as possible. In order to do this,
* (a) the device-interrupt is disabled before entering hd_request(),
* and (b) the timeout-interrupt is disabled before the sti().
*
* Interrupts are still masked (by default) whenever we are exchanging
* data/cmds with a drive, because some drives seem to have very poor
* tolerance for latency during I/O. The IDE driver has support to unmask
* interrupts for non-broken hardware, so use that driver if required.
*/
static void hd_request(void)
{
unsigned int block, nsect, sec, track, head, cyl;
struct hd_i_struct *disk;
struct request *req;
if (do_hd)
return;
repeat:
del_timer(&device_timer);
local_irq_enable();
req = CURRENT;
if (!req) {
do_hd = NULL;
return;
}
if (reset) {
local_irq_disable();
reset_hd();
return;
}
disk = req->rq_disk->private_data;
block = req->sector;
nsect = req->nr_sectors;
if (block >= get_capacity(req->rq_disk) ||
((block+nsect) > get_capacity(req->rq_disk))) {
printk("%s: bad access: block=%d, count=%d\n",
req->rq_disk->disk_name, block, nsect);
end_request(req, 0);
goto repeat;
}
if (disk->special_op) {
if (do_special_op(disk, req))
goto repeat;
return;
}
sec = block % disk->sect + 1;
track = block / disk->sect;
head = track % disk->head;
cyl = track / disk->head;
#ifdef DEBUG
printk("%s: %sing: CHS=%d/%d/%d, sectors=%d, buffer=%p\n",
req->rq_disk->disk_name, (req->cmd == READ)?"read":"writ",
cyl, head, sec, nsect, req->buffer);
#endif
if (blk_fs_request(req)) {
switch (rq_data_dir(req)) {
case READ:
hd_out(disk,nsect,sec,head,cyl,WIN_READ,&read_intr);
if (reset)
goto repeat;
break;
case WRITE:
hd_out(disk,nsect,sec,head,cyl,WIN_WRITE,&write_intr);
if (reset)
goto repeat;
if (wait_DRQ()) {
bad_rw_intr();
goto repeat;
}
outsw(HD_DATA,req->buffer,256);
break;
default:
printk("unknown hd-command\n");
end_request(req, 0);
break;
}
}
}
void do_hd_request(void)
{
int i, r = 0;
unsigned int start_sector, dev, partition;
unsigned int start_sec, head, cyl;
unsigned int nsect;
CHECK_REQUEST;
partition = MINOR(CURRENT_REQ->dev); /* get partition */
start_sector = CURRENT_REQ->start_sector;
nsect = CURRENT_REQ->nr_sectors;
/* need to check if nsect is exceed the partition limit or not */
if (partition >= 5 * NR_HD || nsect > hd[partition].nr_sects) {
end_request(0);
goto repeat; /* repeat defined in blk.h */
}
start_sector += hd[partition].start_sect;
dev = partition / 5;
/* get cyl, head, start_sec number according start_sector */
/* div result: EAX = Quotient, EDX = Remainder */
/*
* start_sector / sect nrs per track = total track number(start_sector)
* ... remainder sector number(start_sec)
*/
__asm__("divl %4"
:"=a" (start_sector), "=d" (start_sec)
:"0" (start_sector), "1" (0), "r" (hd_info[dev].sect));
/* totoal track number / total head nrs = cylinder number(cyl)
* ... head nr(head) */
__asm__("divl %4"
:"=a" (cyl), "=d" (head)
:"0" (start_sector), "1" (0), "r" (hd_info[dev].head));
start_sec++;
if (reset) {
reset = 0;
recalibrate = 1;
reset_hd(CURRENT_DEV);
return;
}
if (recalibrate) {
recalibrate = 0;
hd_out(dev, hd_info[CURRENT_DEV].sect, 0, 0, 0, WIN_RESTORE,
recal_intr);
return;
}
if (CURRENT_REQ->cmd == WRITE) {
hd_out(dev, nsect, start_sec, head, cyl, WIN_WRITE, write_intr);
/* wait DRQ_STAT signal */
for(i = 0; i < 3000 && !(r = inb_p(HD_STATUS) & DRQ_STAT); i++)
/* nothing */ ;
if (!r) {
bad_rw_intr();
goto repeat;
}
/* write 512 byte (1 sector) to HD */
port_write(HD_DATA, CURRENT_REQ->buffer, 256);
} else if (CURRENT_REQ->cmd == READ) {
hd_out(dev, nsect, start_sec, head, cyl, WIN_READ, read_intr);
} else {
panic("unknown hd-command");
}
}
static void reset_hd(int nr)
{
reset_controller();
hd_out(nr, hd_info[nr].sect, hd_info[nr].sect, hd_info[nr].head - 1,
hd_info[nr].cyl, WIN_SPECIFY, recal_intr);
}
static void reset_hd(int nr)
{
reset_controller();
hd_out(nr, _SECT, _SECT, _HEAD - 1, _CYL, WIN_SPECIFY, &do_request);
}
static void reset_hd(int nr)
{
reset_controller();
//printk("In hd.c reset_hd(int nr):nr is %d,hd_info[nr].sect is %d,hd_info[nr].sect is %d,hd_info[nr].head-1 is %d,hd_info[nr].cyl is %d,WIN_SPECIFY is %d,&recal_intr is %d\n",nr,hd_info[nr].sect,hd_info[nr].sect,hd_info[nr].head-1,hd_info[nr].cyl,WIN_SPECIFY,&recal_intr);
hd_out(nr,hd_info[nr].sect,hd_info[nr].sect,hd_info[nr].head-1,hd_info[nr].cyl,WIN_SPECIFY,&recal_intr);
}
static void reset_hd(int nr)
{
reset_controller();
hd_out(nr,hd_info[nr].sect,hd_info[nr].sect,hd_info[nr].head-1,
hd_info[nr].cyl,WIN_SPECIFY,&redo_hd_request);
}
/*
* The driver enables interrupts as much as possible. In order to do this,
* (a) the device-interrupt is disabled before entering hd_request(),
* and (b) the timeout-interrupt is disabled before the sti().
*
* Interrupts are still masked (by default) whenever we are exchanging
* data/cmds with a drive, because some drives seem to have very poor
* tolerance for latency during I/O. The IDE driver has support to unmask
* interrupts for non-broken hardware, so use that driver if required.
*/
static void hd_request(void)
{
unsigned int block, nsect, sec, track, head, cyl;
struct hd_i_struct *disk;
struct request *req;
if (do_hd)
return;
repeat:
del_timer(&device_timer);
if (!hd_req) {
hd_req = blk_fetch_request(hd_queue);
if (!hd_req) {
do_hd = NULL;
return;
}
}
req = hd_req;
if (reset) {
reset_hd();
return;
}
disk = req->rq_disk->private_data;
block = blk_rq_pos(req);
nsect = blk_rq_sectors(req);
if (block >= get_capacity(req->rq_disk) ||
((block+nsect) > get_capacity(req->rq_disk))) {
printk("%s: bad access: block=%d, count=%d\n",
req->rq_disk->disk_name, block, nsect);
hd_end_request_cur(-EIO);
goto repeat;
}
if (disk->special_op) {
if (do_special_op(disk, req))
goto repeat;
return;
}
sec = block % disk->sect + 1;
track = block / disk->sect;
head = track % disk->head;
cyl = track / disk->head;
#ifdef DEBUG
printk("%s: %sing: CHS=%d/%d/%d, sectors=%d, buffer=%p\n",
req->rq_disk->disk_name,
req_data_dir(req) == READ ? "read" : "writ",
cyl, head, sec, nsect, req->buffer);
#endif
if (req->cmd_type == REQ_TYPE_FS) {
switch (rq_data_dir(req)) {
case READ:
hd_out(disk, nsect, sec, head, cyl, ATA_CMD_PIO_READ,
&read_intr);
if (reset)
goto repeat;
break;
case WRITE:
hd_out(disk, nsect, sec, head, cyl, ATA_CMD_PIO_WRITE,
&write_intr);
if (reset)
goto repeat;
if (wait_DRQ()) {
bad_rw_intr();
goto repeat;
}
outsw(HD_DATA, req->buffer, 256);
break;
default:
printk("unknown hd-command\n");
hd_end_request_cur(-EIO);
break;
}
}
}
