ps2esdi.c

讲述linux的初始化过程

	/* some annoyance in the above routine returns TWO drives?
	 Is something else happining in the background?
	 Regaurdless we fix the # of drives again. AJK */
	/* Integrated ESDI Disk and Controller has only one drive! */
	if (adapterID == INTG_ESDI_ID)	/* if not "normal" PS2 ESDI adapter */
		ps2esdi_drives = 1;	/* Not three or two, ONE DAMNIT! */

	current_int_handler = ps2esdi_normal_interrupt_handler;

	ps2esdi_gendisk.nr_real = ps2esdi_drives;

	for (i = 0; i < (MAX_HD << 6); i++)
		ps2esdi_blocksizes[i] = 1024;

	request_dma(dma_arb_level, "ed");
	request_region(io_base, 4, "ed");
	blksize_size[MAJOR_NR] = ps2esdi_blocksizes;

	for (i = 0; i < ps2esdi_drives; i++) {
		register_disk(&ps2esdi_gendisk,MKDEV(MAJOR_NR,i<<6),1<<6,
				&ps2esdi_fops,
				ps2esdi_info[i].head * ps2esdi_info[i].sect *
				ps2esdi_info[i].cyl);
		ps2esdi_valid[i] = 1;
	}
}

static void __init ps2esdi_get_device_cfg(void)
{
	u_short cmd_blk[TYPE_0_CMD_BLK_LENGTH];

	/*BA */ printk("%s: Drive 0\n", DEVICE_NAME);
	current_int_handler = ps2esdi_geometry_int_handler;
	cmd_blk[0] = CMD_GET_DEV_CONFIG | 0x600;
	cmd_blk[1] = 0;
	no_int_yet = TRUE;
	ps2esdi_out_cmd_blk(cmd_blk);
	if (no_int_yet)
		sleep_on(&ps2esdi_int);

	if (ps2esdi_drives > 1) {
		printk("%s: Drive 1\n", DEVICE_NAME);	/*BA */
		cmd_blk[0] = CMD_GET_DEV_CONFIG | (1 << 5) | 0x600;
		cmd_blk[1] = 0;
		no_int_yet = TRUE;
		ps2esdi_out_cmd_blk(cmd_blk);
		if (no_int_yet)
			sleep_on(&ps2esdi_int);
	}			/* if second physical drive is present */
	return;
}

/* strategy routine that handles most of the IO requests */
static void do_ps2esdi_request(request_queue_t * q)
{
	u_int block, count;
	/* since, this routine is called with interrupts cleared - they 
	   must be before it finishes  */
	sti();

#if 0
	printk("%s:got request. device : %d minor : %d command : %d  sector : %ld count : %ld, buffer: %p\n",
	       DEVICE_NAME,
	       CURRENT_DEV, MINOR(CURRENT->rq_dev),
	       CURRENT->cmd, CURRENT->sector,
	       CURRENT->nr_sectors, CURRENT->buffer);
#endif

	/* standard macro that ensures that requests are really on the
	   list + sanity checks.                     */
	INIT_REQUEST;

	if (virt_to_bus(CURRENT->buffer + CURRENT->nr_sectors * 512) > 16 * MB) {
		printk("%s: DMA above 16MB not supported\n", DEVICE_NAME);
		end_request(FAIL);
		if (!QUEUE_EMPTY)
			do_ps2esdi_request(q);
		return;
	}			/* check for above 16Mb dmas */
	if ((CURRENT_DEV < ps2esdi_drives) &&
	    (CURRENT->sector + CURRENT->nr_sectors <=
	     ps2esdi[MINOR(CURRENT->rq_dev)].nr_sects)) {
#if 0
		printk("%s:got request. device : %d minor : %d command : %d  sector : %ld count : %ld\n",
		       DEVICE_NAME,
		       CURRENT_DEV, MINOR(CURRENT->dev),
		       CURRENT->cmd, CURRENT->sector,
		       CURRENT->nr_sectors);
#endif


		block = CURRENT->sector + ps2esdi[MINOR(CURRENT->rq_dev)].start_sect;

#if 0
		printk("%s: blocknumber : %d\n", DEVICE_NAME, block);
#endif
		count = CURRENT->nr_sectors;
		switch (CURRENT->cmd) {
		case READ:
			ps2esdi_readwrite(READ, CURRENT_DEV, block, count);
			return;
			break;
		case WRITE:
			ps2esdi_readwrite(WRITE, CURRENT_DEV, block, count);
			return;
			break;
		default:
			printk("%s: Unknown command\n", DEVICE_NAME);
			end_request(FAIL);
			if (!QUEUE_EMPTY)
				do_ps2esdi_request(q);
			break;
		}		/* handle different commands */
	}
	/* is request is valid */ 
	else {
		printk("Grrr. error. ps2esdi_drives: %d, %lu %lu\n", ps2esdi_drives,
		       CURRENT->sector, ps2esdi[MINOR(CURRENT->rq_dev)].nr_sects);
		end_request(FAIL);
		if (!QUEUE_EMPTY)
			do_ps2esdi_request(q);
	}

}				/* main strategy routine */

/* resets the ESDI adapter */
static void reset_ctrl(void)
{

	u_long expire;
	u_short status;

	/* enable interrupts on the controller */
	status = inb(ESDI_INTRPT);
	outb((status & 0xe0) | ATT_EOI, ESDI_ATTN);	/* to be sure we don't have
							   any interrupt pending... */
	outb_p(CTRL_ENABLE_INTR, ESDI_CONTROL);

	/* read the ESDI status port - if the controller is not busy,
	   simply do a soft reset (fast) - otherwise we'll have to do a
	   hard (slow) reset.  */
	if (!(inb_p(ESDI_STATUS) & STATUS_BUSY)) {
		/*BA */ printk("%s: soft reset...\n", DEVICE_NAME);
		outb_p(CTRL_SOFT_RESET, ESDI_ATTN);
	}
	/* soft reset */ 
	else {
		/*BA */
		printk("%s: hard reset...\n", DEVICE_NAME);
		outb_p(CTRL_HARD_RESET, ESDI_CONTROL);
		expire = jiffies + 2*HZ;
		while (time_before(jiffies, expire));
		outb_p(1, ESDI_CONTROL);
	}			/* hard reset */


}				/* reset the controller */

/* called by the strategy routine to handle read and write requests */
static void ps2esdi_readwrite(int cmd, u_char drive, u_int block, u_int count)
{

	u_short track, head, cylinder, sector;
	u_short cmd_blk[TYPE_1_CMD_BLK_LENGTH];

	/* do some relevant arithmatic */
	CURRENT->current_nr_sectors =
	    (count < (2 * MAX_16BIT / SECT_SIZE)) ? count : (2 * MAX_16BIT / SECT_SIZE);
	track = block / ps2esdi_info[drive].sect;
	head = track % ps2esdi_info[drive].head;
	cylinder = track / ps2esdi_info[drive].head;
	sector = block % ps2esdi_info[drive].sect;

#if 0
	printk("%s: cyl=%d head=%d sect=%d\n", DEVICE_NAME, cylinder, head, sector);
#endif
	/* call the routine that actually fills out a command block */
	ps2esdi_fill_cmd_block
	    (cmd_blk,
	     (cmd == READ) ? CMD_READ : CMD_WRITE,
	     cylinder, head, sector,
	     CURRENT->current_nr_sectors, drive);

	/* send the command block to the controller */
	if (ps2esdi_out_cmd_blk(cmd_blk)) {
		printk("%s: Controller failed\n", DEVICE_NAME);
		if ((++CURRENT->errors) < MAX_RETRIES)
			return do_ps2esdi_request(NULL);
		else {
			end_request(FAIL);
			if (!QUEUE_EMPTY)
				do_ps2esdi_request(NULL);
		}
	}
	/* check for failure to put out the command block */ 
	else {
#if 0
		printk("%s: waiting for xfer\n", DEVICE_NAME);
#endif
		/* turn disk lights on */
		LITE_ON;
	}

}				/* ps2esdi_readwrite */

/* fill out the command block */
static void ps2esdi_fill_cmd_block(u_short * cmd_blk, u_short cmd,
 u_short cyl, u_short head, u_short sector, u_short length, u_char drive)
{

	cmd_blk[0] = (drive << 5) | cmd;
	cmd_blk[1] = length;
	cmd_blk[2] = ((cyl & 0x1f) << 11) | (head << 5) | sector;
	cmd_blk[3] = (cyl & 0x3E0) >> 5;

}				/* fill out the command block */

/* write a command block to the controller */
static int ps2esdi_out_cmd_blk(u_short * cmd_blk)
{

	int i, j;
	u_char status;

	/* enable interrupts */
	outb(CTRL_ENABLE_INTR, ESDI_CONTROL);

	/* do not write to the controller, if it is busy */
	for (i = jiffies + ESDI_STAT_TIMEOUT; time_after(i, jiffies) && (inb(ESDI_STATUS) &
							  STATUS_BUSY););

#if 0
	printk("%s: i(1)=%d\n", DEVICE_NAME, i);
#endif

	/* if device is still busy - then just time out */
	if (inb(ESDI_STATUS) & STATUS_BUSY) {
		printk("%s: ps2esdi_out_cmd timed out (1)\n", DEVICE_NAME);
		return ERROR;
	}			/* timeout ??? */
	/* Set up the attention register in the controller */
	outb(((*cmd_blk) & 0xE0) | 1, ESDI_ATTN);

#if 0
	printk("%s: sending %d words to controller\n", DEVICE_NAME, (((*cmd_blk) >> 14) + 1) << 1);
#endif

	/* one by one send each word out */
	for (i = (((*cmd_blk) >> 14) + 1) << 1; i; i--) {
		status = inb(ESDI_STATUS);
		for (j = jiffies + ESDI_STAT_TIMEOUT;
		     time_after(j, jiffies) && (status & STATUS_BUSY) &&
		   (status & STATUS_CMD_INF); status = inb(ESDI_STATUS));
		if ((status & (STATUS_BUSY | STATUS_CMD_INF)) == STATUS_BUSY) {
#if 0
			printk("%s: sending %04X\n", DEVICE_NAME, *cmd_blk);
#endif
			outw(*cmd_blk++, ESDI_CMD_INT);
		} else {
			printk("%s: ps2esdi_out_cmd timed out while sending command (status=%02X)\n",
			       DEVICE_NAME, status);
			return ERROR;
		}
	}			/* send all words out */
	return OK;
}				/* send out the commands */


/* prepare for dma - do all the necessary setup */
static void ps2esdi_prep_dma(char *buffer, u_short length, u_char dma_xmode)
{
	u_int tc;
	
	buffer=(char *)virt_to_bus(buffer);

#if 0
	printk("ps2esdi: b_wait: %p\n", CURRENT->bh->b_wait);
#endif
	cli();

	outb(dma_arb_level | DMA_MASK_CHAN, PORT_DMA_FN);

	outb(dma_arb_level | DMA_WRITE_ADDR, PORT_DMA_FN);
	outb((u_int) buffer & (u_int) 0xff, PORT_DMA_EX);
	outb(((u_int) buffer >> 8) & (u_int) 0xff, PORT_DMA_EX);
	outb(((u_int) buffer >> 16) & (u_int) 0xff, PORT_DMA_EX);

	outb(dma_arb_level | DMA_WRITE_TC, PORT_DMA_FN);
	tc = (length * SECT_SIZE / 2) - 1;
	outb(tc & 0xff, PORT_DMA_EX);
	outb((tc >> 8) & 0xff, PORT_DMA_EX);

	outb(dma_arb_level | DMA_WRITE_MODE, PORT_DMA_FN);
	outb(dma_xmode, PORT_DMA_EX);

	outb(dma_arb_level | DMA_UNMASK_CHAN, PORT_DMA_FN);

	sti();

}				/* prepare for dma */



static void ps2esdi_interrupt_handler(int irq, void *dev_id,
				      struct pt_regs *regs)
{
	u_int int_ret_code;

	if (inb(ESDI_STATUS) & STATUS_INTR) {
		int_ret_code = inb(ESDI_INTRPT);
		if (current_int_handler) {
			/* Disable adapter interrupts till processing is finished */
			outb(CTRL_DISABLE_INTR, ESDI_CONTROL);
			current_int_handler(int_ret_code);
		} else
			printk("%s: help ! No interrupt handler.\n", DEVICE_NAME);
	} else {
		return;
	}
}

static void ps2esdi_initial_reset_int_handler(u_int int_ret_code)
{

	switch (int_ret_code & 0xf) {
	case INT_RESET:
		/*BA */
		printk("%s: initial reset completed.\n", DEVICE_NAME);
		outb((int_ret_code & 0xe0) | ATT_EOI, ESDI_ATTN);
		wake_up(&ps2esdi_int);
		break;
	case INT_ATTN_ERROR:
		printk("%s: Attention error. interrupt status : %02X\n", DEVICE_NAME,
		       int_ret_code);
		printk("%s: status: %02x\n", DEVICE_NAME, inb(ESDI_STATUS));
		break;
	default:
		printk("%s: initial reset handler received interrupt: %02X\n",
		       DEVICE_NAME, int_ret_code);
		outb((int_ret_code & 0xe0) | ATT_EOI, ESDI_ATTN);
		break;
	}
	outb(CTRL_ENABLE_INTR, ESDI_CONTROL);
}


static void ps2esdi_geometry_int_handler(u_int int_ret_code)
{
	u_int status, drive_num;
	unsigned long rba;
	int i;

	drive_num = int_ret_code >> 5;
	switch (int_ret_code & 0xf) {
	case INT_CMD_COMPLETE:
		for (i = ESDI_TIMEOUT; i & !(inb(ESDI_STATUS) & STATUS_STAT_AVAIL); i--);
		if (!(inb(ESDI_STATUS) & STATUS_STAT_AVAIL)) {
			printk("%s: timeout reading status word\n", DEVICE_NAME);
			outb((int_ret_code & 0xe0) | ATT_EOI, ESDI_ATTN);
			break;
		}
		status = inw(ESDI_STT_INT);
		if ((status & 0x1F) == CMD_GET_DEV_CONFIG) {
#define REPLY_WORDS 5		/* we already read word 0 */
			u_short reply[REPLY_WORDS];

			if (ps2esdi_read_status_words((status >> 8) - 1, REPLY_WORDS, reply)) {
				/*BA */
				printk("%s: Device Configuration Status for drive %u\n",
				       DEVICE_NAME, drive_num);

				printk("%s: Spares/cyls: %u", DEVICE_NAME, reply[0] >> 8);

				printk
				    ("Config bits: %s%s%s%s%s\n",
				     (reply[0] & CONFIG_IS) ? "Invalid Secondary, " : "",
				     ((reply[0] & CONFIG_ZD) && !(reply[0] & CONFIG_IS))
				 ? "Zero Defect, " : "Defects Present, ",
				     (reply[0] & CONFIG_SF) ? "Skewed Format, " : "",
				     (reply[0] & CONFIG_FR) ? "Removable, " : "Non-Removable, ",
				     (reply[0] & CONFIG_RT) ? "No Retries" : "Retries");

				rba = reply[1] | ((unsigned long) reply[2] << 16);
				printk("%s: Number of RBA's: %lu\n", DEVICE_NAME, rba);

				printk("%s: Physical number of cylinders: %u, Sectors/Track: %u, Heads: %u\n",
				       DEVICE_NAME, reply[3], reply[4] >> 8, reply[4] & 0xff);

				if (!ps2esdi_info[drive_num].head) {
					ps2esdi_info[drive_num].head = 64;
					ps2esdi_info[drive_num].sect = 32;
					ps2esdi_info[drive_num].cyl = rba / (64 * 32);
					ps2esdi_info[drive_num].wpcom = 0;
					ps2esdi_info[drive_num].lzone = ps2esdi_info[drive_num].cyl;
					ps2esdi_info[drive_num].ctl = 8;
					if (tp720esdi) {	/* store the retrieved parameters */
						ps2esdi_info[0].head = reply[4] & 0Xff;
						ps2esdi_info[0].sect = reply[4] >> 8;
						ps2esdi_info[0].cyl = reply[3];
						ps2esdi_info[0].wpcom = 0;
						ps2esdi_info[0].lzone = reply[3];
					} else {
						if (!intg_esdi)
							ps2esdi_drives++;
					}
				}