viotape.c

来自「linux 内核源代码」· C语言 代码 · 共 1,028 行 · 第 1/2 页

	int ret;
	struct viot_devinfo_struct devi;
	struct mtop mtc;
	u32 myOp;
	struct op_struct *op = get_op_struct();

	if (op == NULL)
		return -ENOMEM;

	get_dev_info(file->f_path.dentry->d_inode, &devi);

	down(&reqSem);

	ret = -EINVAL;

	switch (cmd) {
	case MTIOCTOP:
		ret = -EFAULT;
		/*
		 * inode is null if and only if we (the kernel)
		 * made the request
		 */
		if (inode == NULL)
			memcpy(&mtc, (void *) arg, sizeof(struct mtop));
		else if (copy_from_user((char *)&mtc, (char *)arg,
					sizeof(struct mtop)))
			goto free_op;

		ret = -EIO;
		switch (mtc.mt_op) {
		case MTRESET:
			myOp = VIOTAPOP_RESET;
			break;
		case MTFSF:
			myOp = VIOTAPOP_FSF;
			break;
		case MTBSF:
			myOp = VIOTAPOP_BSF;
			break;
		case MTFSR:
			myOp = VIOTAPOP_FSR;
			break;
		case MTBSR:
			myOp = VIOTAPOP_BSR;
			break;
		case MTWEOF:
			myOp = VIOTAPOP_WEOF;
			break;
		case MTREW:
			myOp = VIOTAPOP_REW;
			break;
		case MTNOP:
			myOp = VIOTAPOP_NOP;
			break;
		case MTEOM:
			myOp = VIOTAPOP_EOM;
			break;
		case MTERASE:
			myOp = VIOTAPOP_ERASE;
			break;
		case MTSETBLK:
			myOp = VIOTAPOP_SETBLK;
			break;
		case MTSETDENSITY:
			myOp = VIOTAPOP_SETDENSITY;
			break;
		case MTTELL:
			myOp = VIOTAPOP_GETPOS;
			break;
		case MTSEEK:
			myOp = VIOTAPOP_SETPOS;
			break;
		case MTSETPART:
			myOp = VIOTAPOP_SETPART;
			break;
		case MTOFFL:
			myOp = VIOTAPOP_UNLOAD;
			break;
		default:
			printk(VIOTAPE_KERN_WARN "MTIOCTOP called "
					"with invalid op 0x%x\n", mtc.mt_op);
			goto free_op;
		}

		/*
		 * if we moved the head, we are no longer
		 * reading or writing
		 */
		switch (mtc.mt_op) {
		case MTFSF:
		case MTBSF:
		case MTFSR:
		case MTBSR:
		case MTTELL:
		case MTSEEK:
		case MTREW:
			chg_state(devi.devno, VIOT_IDLE, file);
		}

		init_completion(&op->com);
		hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
				HvLpEvent_Type_VirtualIo,
				viomajorsubtype_tape | viotapeop,
				HvLpEvent_AckInd_DoAck,
				HvLpEvent_AckType_ImmediateAck,
				viopath_sourceinst(viopath_hostLp),
				viopath_targetinst(viopath_hostLp),
				(u64)(unsigned long)op,
				VIOVERSION << 16,
				((u64)devi.devno << 48), 0,
				(((u64)myOp) << 32) | mtc.mt_count, 0);
		if (hvrc != HvLpEvent_Rc_Good) {
			printk(VIOTAPE_KERN_WARN "hv error on op %d\n",
					(int)hvrc);
			goto free_op;
		}
		wait_for_completion(&op->com);
		ret = tape_rc_to_errno(op->rc, "tape operation", devi.devno);
		goto free_op;

	case MTIOCGET:
		ret = -EIO;
		init_completion(&op->com);
		hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
				HvLpEvent_Type_VirtualIo,
				viomajorsubtype_tape | viotapegetstatus,
				HvLpEvent_AckInd_DoAck,
				HvLpEvent_AckType_ImmediateAck,
				viopath_sourceinst(viopath_hostLp),
				viopath_targetinst(viopath_hostLp),
				(u64)(unsigned long)op, VIOVERSION << 16,
				((u64)devi.devno << 48), 0, 0, 0);
		if (hvrc != HvLpEvent_Rc_Good) {
			printk(VIOTAPE_KERN_WARN "hv error on op %d\n",
					(int)hvrc);
			goto free_op;
		}
		wait_for_completion(&op->com);

		/* Operation is complete - grab the error code */
		ret = tape_rc_to_errno(op->rc, "get status", devi.devno);
		free_op_struct(op);
		up(&reqSem);

		if ((ret == 0) && copy_to_user((void *)arg,
					&viomtget[devi.devno],
					sizeof(viomtget[0])))
			ret = -EFAULT;
		return ret;
	case MTIOCPOS:
		printk(VIOTAPE_KERN_WARN "Got an (unsupported) MTIOCPOS\n");
		break;
	default:
		printk(VIOTAPE_KERN_WARN "got an unsupported ioctl 0x%0x\n",
				cmd);
		break;
	}

free_op:
	free_op_struct(op);
	up(&reqSem);
	return ret;
}

static int viotap_open(struct inode *inode, struct file *file)
{
	HvLpEvent_Rc hvrc;
	struct viot_devinfo_struct devi;
	int ret;
	struct op_struct *op = get_op_struct();

	if (op == NULL)
		return -ENOMEM;

	get_dev_info(file->f_path.dentry->d_inode, &devi);

	/* Note: We currently only support one mode! */
	if ((devi.devno >= viotape_numdev) || (devi.mode)) {
		ret = -ENODEV;
		goto free_op;
	}

	init_completion(&op->com);

	hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
			HvLpEvent_Type_VirtualIo,
			viomajorsubtype_tape | viotapeopen,
			HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
			viopath_sourceinst(viopath_hostLp),
			viopath_targetinst(viopath_hostLp),
			(u64)(unsigned long)op, VIOVERSION << 16,
			((u64)devi.devno << 48), 0, 0, 0);
	if (hvrc != 0) {
		printk(VIOTAPE_KERN_WARN "bad rc on signalLpEvent %d\n",
				(int) hvrc);
		ret = -EIO;
		goto free_op;
	}

	wait_for_completion(&op->com);
	ret = tape_rc_to_errno(op->rc, "open", devi.devno);

free_op:
	free_op_struct(op);
	return ret;
}


static int viotap_release(struct inode *inode, struct file *file)
{
	HvLpEvent_Rc hvrc;
	struct viot_devinfo_struct devi;
	int ret = 0;
	struct op_struct *op = get_op_struct();

	if (op == NULL)
		return -ENOMEM;
	init_completion(&op->com);

	get_dev_info(file->f_path.dentry->d_inode, &devi);

	if (devi.devno >= viotape_numdev) {
		ret = -ENODEV;
		goto free_op;
	}

	chg_state(devi.devno, VIOT_IDLE, file);

	if (devi.rewind) {
		hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
				HvLpEvent_Type_VirtualIo,
				viomajorsubtype_tape | viotapeop,
				HvLpEvent_AckInd_DoAck,
				HvLpEvent_AckType_ImmediateAck,
				viopath_sourceinst(viopath_hostLp),
				viopath_targetinst(viopath_hostLp),
				(u64)(unsigned long)op, VIOVERSION << 16,
				((u64)devi.devno << 48), 0,
				((u64)VIOTAPOP_REW) << 32, 0);
		wait_for_completion(&op->com);

		tape_rc_to_errno(op->rc, "rewind", devi.devno);
	}

	hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
			HvLpEvent_Type_VirtualIo,
			viomajorsubtype_tape | viotapeclose,
			HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
			viopath_sourceinst(viopath_hostLp),
			viopath_targetinst(viopath_hostLp),
			(u64)(unsigned long)op, VIOVERSION << 16,
			((u64)devi.devno << 48), 0, 0, 0);
	if (hvrc != 0) {
		printk(VIOTAPE_KERN_WARN "bad rc on signalLpEvent %d\n",
				(int) hvrc);
		ret = -EIO;
		goto free_op;
	}

	wait_for_completion(&op->com);

	if (op->rc)
		printk(VIOTAPE_KERN_WARN "close failed\n");

free_op:
	free_op_struct(op);
	return ret;
}

const struct file_operations viotap_fops = {
	.owner =	THIS_MODULE,
	.read =		viotap_read,
	.write =	viotap_write,
	.ioctl =	viotap_ioctl,
	.open =		viotap_open,
	.release =	viotap_release,
};

/* Handle interrupt events for tape */
static void vioHandleTapeEvent(struct HvLpEvent *event)
{
	int tapeminor;
	struct op_struct *op;
	struct viotapelpevent *tevent = (struct viotapelpevent *)event;

	if (event == NULL) {
		/* Notification that a partition went away! */
		if (!viopath_isactive(viopath_hostLp)) {
			/* TODO! Clean up */
		}
		return;
	}

	tapeminor = event->xSubtype & VIOMINOR_SUBTYPE_MASK;
	op = (struct op_struct *)event->xCorrelationToken;
	switch (tapeminor) {
	case viotapeopen:
	case viotapeclose:
		op->rc = tevent->sub_type_result;
		complete(&op->com);
		break;
	case viotaperead:
		op->rc = tevent->sub_type_result;
		op->count = tevent->len;
		complete(&op->com);
		break;
	case viotapewrite:
		if (op->non_blocking) {
			dma_free_coherent(op->dev, op->count,
					op->buffer, op->dmaaddr);
			free_op_struct(op);
			up(&reqSem);
		} else {
			op->rc = tevent->sub_type_result;
			op->count = tevent->len;
			complete(&op->com);
		}
		break;
	case viotapeop:
	case viotapegetpos:
	case viotapesetpos:
	case viotapegetstatus:
		if (op) {
			op->count = tevent->u.op.count;
			op->rc = tevent->sub_type_result;
			if (!op->non_blocking)
				complete(&op->com);
		}
		break;
	default:
		printk(VIOTAPE_KERN_WARN "weird ack\n");
	}
}

static int viotape_probe(struct vio_dev *vdev, const struct vio_device_id *id)
{
	int i = vdev->unit_address;
	int j;
	struct device_node *node = vdev->dev.archdata.of_node;

	if (i > VIOTAPE_MAX_TAPE)
		return -ENODEV;
	if (!node)
		return -ENODEV;

	if (i >= viotape_numdev)
		viotape_numdev = i + 1;

	tape_device[i] = &vdev->dev;
	viotape_unitinfo[i].rsrcname = of_get_property(node,
					"linux,vio_rsrcname", NULL);
	viotape_unitinfo[i].type = of_get_property(node, "linux,vio_type",
					NULL);
	viotape_unitinfo[i].model = of_get_property(node, "linux,vio_model",
					NULL);

	state[i].cur_part = 0;
	for (j = 0; j < MAX_PARTITIONS; ++j)
		state[i].part_stat_rwi[j] = VIOT_IDLE;
	device_create(tape_class, NULL, MKDEV(VIOTAPE_MAJOR, i),
			"iseries!vt%d", i);
	device_create(tape_class, NULL, MKDEV(VIOTAPE_MAJOR, i | 0x80),
			"iseries!nvt%d", i);
	printk(VIOTAPE_KERN_INFO "tape iseries/vt%d is iSeries "
			"resource %10.10s type %4.4s, model %3.3s\n",
			i, viotape_unitinfo[i].rsrcname,
			viotape_unitinfo[i].type, viotape_unitinfo[i].model);
	return 0;
}

static int viotape_remove(struct vio_dev *vdev)
{
	int i = vdev->unit_address;

	device_destroy(tape_class, MKDEV(VIOTAPE_MAJOR, i | 0x80));
	device_destroy(tape_class, MKDEV(VIOTAPE_MAJOR, i));
	return 0;
}

/**
 * viotape_device_table: Used by vio.c to match devices that we
 * support.
 */
static struct vio_device_id viotape_device_table[] __devinitdata = {
	{ "byte", "IBM,iSeries-viotape" },
	{ "", "" }
};
MODULE_DEVICE_TABLE(vio, viotape_device_table);

static struct vio_driver viotape_driver = {
	.id_table = viotape_device_table,
	.probe = viotape_probe,
	.remove = viotape_remove,
	.driver = {
		.name = "viotape",
		.owner = THIS_MODULE,
	}
};


int __init viotap_init(void)
{
	int ret;
	struct proc_dir_entry *e;

	if (!firmware_has_feature(FW_FEATURE_ISERIES))
		return -ENODEV;

	op_struct_list = NULL;
	if ((ret = add_op_structs(VIOTAPE_MAXREQ)) < 0) {
		printk(VIOTAPE_KERN_WARN "couldn't allocate op structs\n");
		return ret;
	}
	spin_lock_init(&op_struct_list_lock);

	sema_init(&reqSem, VIOTAPE_MAXREQ);

	if (viopath_hostLp == HvLpIndexInvalid) {
		vio_set_hostlp();
		if (viopath_hostLp == HvLpIndexInvalid) {
			ret = -ENODEV;
			goto clear_op;
		}
	}

	ret = viopath_open(viopath_hostLp, viomajorsubtype_tape,
			VIOTAPE_MAXREQ + 2);
	if (ret) {
		printk(VIOTAPE_KERN_WARN
				"error on viopath_open to hostlp %d\n", ret);
		ret = -EIO;
		goto clear_op;
	}

	printk(VIOTAPE_KERN_INFO "vers " VIOTAPE_VERSION
			", hosting partition %d\n", viopath_hostLp);

	vio_setHandler(viomajorsubtype_tape, vioHandleTapeEvent);

	ret = register_chrdev(VIOTAPE_MAJOR, "viotape", &viotap_fops);
	if (ret < 0) {
		printk(VIOTAPE_KERN_WARN "Error registering viotape device\n");
		goto clear_handler;
	}

	tape_class = class_create(THIS_MODULE, "tape");
	if (IS_ERR(tape_class)) {
		printk(VIOTAPE_KERN_WARN "Unable to allocat class\n");
		ret = PTR_ERR(tape_class);
		goto unreg_chrdev;
	}

	ret = vio_register_driver(&viotape_driver);
	if (ret)
		goto unreg_class;

	e = create_proc_entry("iSeries/viotape", S_IFREG|S_IRUGO, NULL);
	if (e) {
		e->owner = THIS_MODULE;
		e->proc_fops = &proc_viotape_operations;
	}

	return 0;

unreg_class:
	class_destroy(tape_class);
unreg_chrdev:
	unregister_chrdev(VIOTAPE_MAJOR, "viotape");
clear_handler:
	vio_clearHandler(viomajorsubtype_tape);
	viopath_close(viopath_hostLp, viomajorsubtype_tape, VIOTAPE_MAXREQ + 2);
clear_op:
	clear_op_struct_pool();
	return ret;
}

/* Give a new state to the tape object */
static int chg_state(int index, unsigned char new_state, struct file *file)
{
	unsigned char *cur_state =
	    &state[index].part_stat_rwi[state[index].cur_part];
	int rc = 0;

	/* if the same state, don't bother */
	if (*cur_state == new_state)
		return 0;

	/* write an EOF if changing from writing to some other state */
	if (*cur_state == VIOT_WRITING) {
		struct mtop write_eof = { MTWEOF, 1 };

		rc = viotap_ioctl(NULL, file, MTIOCTOP,
				  (unsigned long)&write_eof);
	}
	*cur_state = new_state;
	return rc;
}

/* Cleanup */
static void __exit viotap_exit(void)
{
	remove_proc_entry("iSeries/viotape", NULL);
	vio_unregister_driver(&viotape_driver);
	class_destroy(tape_class);
	unregister_chrdev(VIOTAPE_MAJOR, "viotape");
	viopath_close(viopath_hostLp, viomajorsubtype_tape, VIOTAPE_MAXREQ + 2);
	vio_clearHandler(viomajorsubtype_tape);
	clear_op_struct_pool();
}

MODULE_LICENSE("GPL");
module_init(viotap_init);
module_exit(viotap_exit);