scsi_debug.c

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#if 0
			/* Simulate a disk change */
			if (block == 0xfff0) {
				sense_buffer[0] = 0x70;
				sense_buffer[2] = UNIT_ATTENTION;
				starts[0] += 10;
				starts[1] += 10;
				starts[2] += 10;

#ifdef DEBUG
				{
					int i;
					printk("scsi_debug: Filling sense buffer:");
					for (i = 0; i < 12; i++)
						printk("%d ", sense_buffer[i]);
					printk("\n");
				};
#endif
				scsi_debug_errsts = (COMMAND_COMPLETE << 8) | (CHECK_CONDITION << 1);
				break;
			}	/* End phony disk change code */
#endif

#ifdef CLEAR
			memcpy(buff, &target, sizeof(target));
			memcpy(buff + sizeof(target), cmd, 24);
			memcpy(buff + 60, &block, sizeof(block));
			memcpy(buff + 64, SCpnt, sizeof(Scsi_Cmnd));
#endif
			nbytes -= bufflen;
			if (SCpnt->use_sg) {
#ifdef CLEAR
				memcpy(buff + 128, bh, sizeof(struct buffer_head));
#endif
				block += bufflen >> 9;
				bh = bh->b_reqnext;
				sgcount++;
				if (nbytes) {
					if (!bh)
						panic("Too few blocks for linked request.");
					buff = sgpnt[sgcount].address;
					bufflen = sgpnt[sgcount].length;
				};
			}
		} while (nbytes);

		SCpnt->result = 0;
		(done) (SCpnt);
		return 0;

		if (SCpnt->use_sg && !scsi_debug_errsts)
			if (bh)
				scsi_dump(SCpnt, 0);
		break;
	case WRITE_10:
	case WRITE_6:
#ifdef DEBUG
		printk("Write\n");
#endif
		if ((*cmd) == WRITE_10)
			block = cmd[5] + (cmd[4] << 8) + (cmd[3] << 16) + (cmd[2] << 24);
		else
			block = cmd[3] + (cmd[2] << 8) + ((cmd[1] & 0x1f) << 16);
		VERIFY_DEBUG(WRITE);
		/*      printk("(w%d)",SCpnt->request.nr_sectors); */
		if (SCpnt->use_sg) {
			if ((bufflen >> 9) != SCpnt->request.nr_sectors)
				panic("Trying to write wrong number of blocks\n");
			sgpnt = (struct scatterlist *) buff;
			buff = sgpnt[sgcount].address;
		};
#if 0
		if (block != *((unsigned long *) (buff + 60))) {
			printk("%x %x :", block, *((unsigned long *) (buff + 60)));
			scsi_dump(SCpnt, 1);
			panic("Bad block written.\n");
		};
#endif
		scsi_debug_errsts = 0;
		break;
	case MODE_SENSE:
		/*
		 * Used to detect write protected status.
		 */
		scsi_debug_errsts = 0;
		memset(buff, 0, 6);
		break;
	default:
		SCSI_LOG_LLQUEUE(3, printk("Unknown command %d\n", *cmd));
		SCpnt->result = DID_NO_CONNECT << 16;
		done(SCpnt);
		return 0;
	};

	save_flags(flags);
	cli();
	for (i = 0; i < SCSI_DEBUG_MAILBOXES; i++) {
		if (timeout[i].function == NULL)
			break;
	};

	/*
	 * If all of the slots are full, just return 1.  The new error handling scheme
	 * allows this, and the mid-level should queue things.
	 */
	if (i >= SCSI_DEBUG_MAILBOXES || timeout[i].function != 0) {
		SCSI_LOG_LLQUEUE(1, printk("Command rejected - host busy\n"));
		restore_flags(flags);
		return 1;
	}
	SCSI_LOG_LLQUEUE(1, printk("Command accepted - slot %d\n", i));

#ifdef IMMEDIATE
	if (!scsi_debug_lockup) {
		SCpnt->result = scsi_debug_errsts;
		SCint[i] = SCpnt;
		do_done[i] = done;
		scsi_debug_intr_handle(i);	/* No timer - do this one right away */
	}
	restore_flags(flags);
#else

	SCpnt->result = scsi_debug_errsts;
	timeout[i].function = scsi_debug_intr_handle;
	timeout[i].data = i;
	timeout[i].expires = jiffies + DISK_SPEED;
	SCint[i] = SCpnt;
	do_done[i] = done;

	restore_flags(flags);
	add_timer(&timeout[i]);
	if (!done)
		panic("scsi_debug_queuecommand: done can't be NULL\n");

#if 0
	printk("Sending command (%d %x %d %d)...", i, done, timeout[i].expires, jiffies);
#endif
#endif

	return 0;
}

static void scsi_debug_send_self_command(struct Scsi_Host * shpnt)
{
	static unsigned char cmd[6] =
	{TEST_UNIT_READY, 0, 0, 0, 0, 0};

        Scsi_Request  * scp;
        Scsi_Device   * sdev;
        
        printk("Allocating host dev\n");
        sdev = scsi_get_host_dev(shpnt);
        if(sdev==NULL)
        {
        	printk("Out of memory.\n");
        	return;
        }
        
        printk("Got %p. Allocating command block\n", sdev);
        scp  = scsi_allocate_request(sdev);
        printk("Got %p\n", scp);
        
        if(scp==NULL)
        {
        	printk("Out of memory.\n");
        	goto bail;
        }

        scp->sr_cmd_len = 6;
        scp->sr_use_sg = 0;
        
        printk("Sending command\n");
        scsi_wait_req (scp, (void *) cmd, (void *) NULL,
                       0, 100, 3);
        
        printk("Releasing command\n");
        scsi_release_request(scp);
bail:
	printk("Freeing device\n");
        scsi_free_host_dev(sdev);
}

/* A "high" level interrupt handler.  This should be called once per jiffy
 * to simulate a regular scsi disk.  We use a timer to do this. */

static void scsi_debug_intr_handle(unsigned long indx)
{
	Scsi_Cmnd *SCtmp;
	void (*my_done) (Scsi_Cmnd *);
#ifdef DEBUG
	int to;
#endif

#if 0
	del_timer(&timeout[indx]);
#endif

	SCtmp = (Scsi_Cmnd *) SCint[indx];
	my_done = do_done[indx];
	do_done[indx] = NULL;
	timeout[indx].function = NULL;
	SCint[indx] = NULL;

	if (!my_done) {
		printk("scsi_debug_intr_handle: Unexpected interrupt\n");
		return;
	}
#ifdef DEBUG
	printk("In intr_handle...");
	printk("...done %d %x %d %d\n", i, my_done, to, jiffies);
	printk("In intr_handle: %d %x %x\n", i, SCtmp, my_done);
#endif

	my_done(SCtmp);
#ifdef DEBUG
	printk("Called done.\n");
#endif
}


int scsi_debug_detect(Scsi_Host_Template * tpnt)
{
	int i;

	for (i = 0; i < NR_HOSTS_PRESENT; i++) {
		tpnt->proc_name = "scsi_debug";	/* Huh? In the loop??? */
		scsi_register(tpnt, 0);
	}
	return NR_HOSTS_PRESENT;
}

int scsi_debug_abort(Scsi_Cmnd * SCpnt)
{
#if 0
	int j;
	void (*my_done) (Scsi_Cmnd *);
	unsigned long flags;
#endif

	DEB(printk("scsi_debug_abort\n"));
#if 0
	SCpnt->result = SCpnt->abort_reason << 16;
	for (j = 0; j < SCSI_DEBUG_MAILBOXES; j++) {
		if (SCpnt == SCint[j]) {
			my_done = do_done[j];
			my_done(SCpnt);
			save_flags(flags);
			cli();
			timeout[j] = 0;
			SCint[j] = NULL;
			do_done[j] = NULL;
			restore_flags(flags);
		};
	};
#endif
	return SCSI_ABORT_SNOOZE;
}

int scsi_debug_biosparam(Disk * disk, kdev_t dev, int *info)
{
	int size = disk->capacity;
	info[0] = N_HEAD;
	info[1] = N_SECTOR;
	info[2] = N_CYLINDER;
	if (info[2] >= 1024)
		info[2] = 1024;
	return 0;
}

int scsi_debug_reset(Scsi_Cmnd * SCpnt, unsigned int why)
{
	int i;
	unsigned long flags;

	void (*my_done) (Scsi_Cmnd *);
	printk("Bus unlocked by reset - %d\n", why);
	scsi_debug_lockup = 0;
	DEB(printk("scsi_debug_reset called\n"));
	for (i = 0; i < SCSI_DEBUG_MAILBOXES; i++) {
		if (SCint[i] == NULL)
			continue;
		SCint[i]->result = DID_RESET << 16;
		my_done = do_done[i];
		my_done(SCint[i]);
		save_flags(flags);
		cli();
		SCint[i] = NULL;
		do_done[i] = NULL;
		timeout[i].function = NULL;
		restore_flags(flags);
	}
	return SCSI_RESET_SUCCESS;
}

const char *scsi_debug_info(void)
{
	static char buffer[] = " ";	/* looks nicer without anything here */
	return buffer;
}

/* scsi_debug_proc_info
 * Used if the driver currently has no own support for /proc/scsi
 */
int scsi_debug_proc_info(char *buffer, char **start, off_t offset,
			 int length, int inode, int inout)
{
	int len, pos, begin;
	int orig_length;

	orig_length = length;

	if (inout == 1) {
		/* First check for the Signature */
		if (length >= 10 && strncmp(buffer, "scsi_debug", 10) == 0) {
			buffer += 11;
			length -= 11;

			if (buffer[length - 1] == '\n') {
				buffer[length - 1] = '\0';
				length--;
			}
			/*
			 * OK, we are getting some kind of command.  Figure out
			 * what we are supposed to do here.  Simulate bus lockups
			 * to test our reset capability.
			 */
			if (length == 4 && strncmp(buffer, "test", length) == 0) {
                                printk("Testing send self command %p\n", SHpnt);
                                scsi_debug_send_self_command(SHpnt);
                                return orig_length;
                        }
			if (length == 6 && strncmp(buffer, "lockup", length) == 0) {
				scsi_debug_lockup = 1;
				return orig_length;
			}
			if (length == 6 && strncmp(buffer, "unlock", length) == 0) {
				scsi_debug_lockup = 0;
				return orig_length;
			}
			printk("Unknown command:%s (%d)\n", buffer, length);
		} else
			printk("Wrong Signature:%10s\n", (char *) buffer);

		return -EINVAL;

	}
	begin = 0;
	pos = len = sprintf(buffer,
	"This driver is not a real scsi driver, but it plays one on TV.\n"
	 "It is very handy for debugging specific problems because you\n"
			 "can simulate a variety of error conditions\n");
	if (pos < offset) {
		len = 0;
		begin = pos;
	}
	*start = buffer + (offset - begin);	/* Start of wanted data */
	len -= (offset - begin);
	if (len > length)
		len = length;

	return (len);
}

#ifdef CONFIG_USER_DEBUG
/*
 * This is a hack for the user space emulator.  It allows us to
 * "insert" arbitrary numbers of additional drivers.
 */
void *scsi_debug_get_handle(void)
{
	static Scsi_Host_Template driver_copy = SCSI_DEBUG;
	void *rtn;
	rtn = kmalloc(sizeof(driver_copy), GFP_ATOMIC);
	if(rtn==NULL)
		return NULL;
	memcpy(rtn, (void *) &driver_copy, sizeof(driver_copy));
	return rtn;
}
#endif

/* Eventually this will go into an include file, but this will be later */
static Scsi_Host_Template driver_template = SCSI_DEBUG;

#include "scsi_module.c"

/*
 * Overrides for Emacs so that we almost follow Linus's tabbing style.
 * Emacs will notice this stuff at the end of the file and automatically
 * adjust the settings for this buffer only.  This must remain at the end
 * of the file.
 * ---------------------------------------------------------------------------
 * Local variables:
 * c-indent-level: 4
 * c-brace-imaginary-offset: 0
 * c-brace-offset: -4
 * c-argdecl-indent: 4
 * c-label-offset: -4
 * c-continued-statement-offset: 4
 * c-continued-brace-offset: 0
 * indent-tabs-mode: nil
 * tab-width: 8
 * End:
 */