chsc.c

LINUX 2.6.17.4的源码

		/* Check if we might have lost some information. */
		if (sei_area->flags & 0x40)
			CIO_CRW_EVENT(2, "chsc_process_crw: Event information "
				       "has been lost due to overflow!\n");

		if (sei_area->rs != 4) {
			CIO_CRW_EVENT(2, "chsc_process_crw: reporting source "
				      "(%04X) isn't a chpid!\n",
				      sei_area->rsid);
			continue;
		}

		/* which kind of information was stored? */
		switch (sei_area->cc) {
		case 1: /* link incident*/
			CIO_CRW_EVENT(4, "chsc_process_crw: "
				      "channel subsystem reports link incident,"
				      " reporting source is chpid %x\n",
				      sei_area->rsid);
			chpid = __get_chpid_from_lir(sei_area->ccdf);
			if (chpid < 0)
				CIO_CRW_EVENT(4, "%s: Invalid LIR, skipping\n",
					      __FUNCTION__);
			else
				s390_set_chpid_offline(chpid);
			break;
			
		case 2: /* i/o resource accessibiliy */
			CIO_CRW_EVENT(4, "chsc_process_crw: "
				      "channel subsystem reports some I/O "
				      "devices may have become accessible\n");
			pr_debug("Data received after sei: \n");
			pr_debug("Validity flags: %x\n", sei_area->vf);
			
			/* allocate a new channel path structure, if needed */
			status = get_chp_status(sei_area->rsid);
			if (status < 0)
				new_channel_path(sei_area->rsid);
			else if (!status)
				break;
			dev = get_device(&css[0]->chps[sei_area->rsid]->dev);
			res_data.chp = to_channelpath(dev);
			pr_debug("chpid: %x", sei_area->rsid);
			if ((sei_area->vf & 0xc0) != 0) {
				res_data.fla = sei_area->fla;
				if ((sei_area->vf & 0xc0) == 0xc0) {
					pr_debug(" full link addr: %x",
						 sei_area->fla);
					res_data.fla_mask = 0xffff;
				} else {
					pr_debug(" link addr: %x",
						 sei_area->fla);
					res_data.fla_mask = 0xff00;
				}
			}
			ret = s390_process_res_acc(&res_data);
			pr_debug("\n\n");
			put_device(dev);
			break;
			
		default: /* other stuff */
			CIO_CRW_EVENT(4, "chsc_process_crw: event %d\n",
				      sei_area->cc);
			break;
		}
	} while (sei_area->flags & 0x80);
	return ret;
}

static inline int
__chp_add_new_sch(struct subchannel_id schid)
{
	struct schib schib;
	int ret;

	if (stsch(schid, &schib))
		/* We're through */
		return need_rescan ? -EAGAIN : -ENXIO;

	/* Put it on the slow path. */
	ret = css_enqueue_subchannel_slow(schid);
	if (ret) {
		css_clear_subchannel_slow_list();
		need_rescan = 1;
		return -EAGAIN;
	}
	return 0;
}


static int
__chp_add(struct subchannel_id schid, void *data)
{
	int i;
	struct channel_path *chp;
	struct subchannel *sch;

	chp = (struct channel_path *)data;
	sch = get_subchannel_by_schid(schid);
	if (!sch)
		/* Check if the subchannel is now available. */
		return __chp_add_new_sch(schid);
	spin_lock_irq(&sch->lock);
	for (i=0; i<8; i++)
		if (sch->schib.pmcw.chpid[i] == chp->id) {
			if (stsch(sch->schid, &sch->schib) != 0) {
				/* Endgame. */
				spin_unlock_irq(&sch->lock);
				return -ENXIO;
			}
			break;
		}
	if (i==8) {
		spin_unlock_irq(&sch->lock);
		return 0;
	}
	sch->lpm = ((sch->schib.pmcw.pim &
		     sch->schib.pmcw.pam &
		     sch->schib.pmcw.pom)
		    | 0x80 >> i) & sch->opm;

	if (sch->driver && sch->driver->verify)
		sch->driver->verify(&sch->dev);

	spin_unlock_irq(&sch->lock);
	put_device(&sch->dev);
	return 0;
}

static int
chp_add(int chpid)
{
	int rc;
	char dbf_txt[15];
	struct device *dev;

	if (!get_chp_status(chpid))
		return 0; /* no need to do the rest */
	
	sprintf(dbf_txt, "cadd%x", chpid);
	CIO_TRACE_EVENT(2, dbf_txt);

	dev = get_device(&css[0]->chps[chpid]->dev);
	rc = for_each_subchannel(__chp_add, to_channelpath(dev));
	if (css_slow_subchannels_exist())
		rc = -EAGAIN;
	if (rc != -EAGAIN)
		rc = 0;
	put_device(dev);
	return rc;
}

/* 
 * Handling of crw machine checks with channel path source.
 */
int
chp_process_crw(int chpid, int on)
{
	if (on == 0) {
		/* Path has gone. We use the link incident routine.*/
		s390_set_chpid_offline(chpid);
		return 0; /* De-register is async anyway. */
	}
	/*
	 * Path has come. Allocate a new channel path structure,
	 * if needed.
	 */
	if (get_chp_status(chpid) < 0)
		new_channel_path(chpid);
	/* Avoid the extra overhead in process_rec_acc. */
	return chp_add(chpid);
}

static inline int
__check_for_io_and_kill(struct subchannel *sch, int index)
{
	int cc;

	if (!device_is_online(sch))
		/* cio could be doing I/O. */
		return 0;
	cc = stsch(sch->schid, &sch->schib);
	if (cc)
		return 0;
	if (sch->schib.scsw.actl && sch->schib.pmcw.lpum == (0x80 >> index)) {
		device_set_waiting(sch);
		return 1;
	}
	return 0;
}

static inline void
__s390_subchannel_vary_chpid(struct subchannel *sch, __u8 chpid, int on)
{
	int chp, old_lpm;
	unsigned long flags;

	if (!sch->ssd_info.valid)
		return;
	
	spin_lock_irqsave(&sch->lock, flags);
	old_lpm = sch->lpm;
	for (chp = 0; chp < 8; chp++) {
		if (sch->ssd_info.chpid[chp] != chpid)
			continue;

		if (on) {
			sch->opm |= (0x80 >> chp);
			sch->lpm |= (0x80 >> chp);
			if (!old_lpm)
				device_trigger_reprobe(sch);
			else if (sch->driver && sch->driver->verify)
				sch->driver->verify(&sch->dev);
		} else {
			sch->opm &= ~(0x80 >> chp);
			sch->lpm &= ~(0x80 >> chp);
			/*
			 * Give running I/O a grace period in which it
			 * can successfully terminate, even using the
			 * just varied off path. Then kill it.
			 */
			if (!__check_for_io_and_kill(sch, chp) && !sch->lpm) {
				if (css_enqueue_subchannel_slow(sch->schid)) {
					css_clear_subchannel_slow_list();
					need_rescan = 1;
				}
			} else if (sch->driver && sch->driver->verify)
				sch->driver->verify(&sch->dev);
		}
		break;
	}
	spin_unlock_irqrestore(&sch->lock, flags);
}

static int
s390_subchannel_vary_chpid_off(struct device *dev, void *data)
{
	struct subchannel *sch;
	__u8 *chpid;

	sch = to_subchannel(dev);
	chpid = data;

	__s390_subchannel_vary_chpid(sch, *chpid, 0);
	return 0;
}

static int
s390_subchannel_vary_chpid_on(struct device *dev, void *data)
{
	struct subchannel *sch;
	__u8 *chpid;

	sch = to_subchannel(dev);
	chpid = data;

	__s390_subchannel_vary_chpid(sch, *chpid, 1);
	return 0;
}

static int
__s390_vary_chpid_on(struct subchannel_id schid, void *data)
{
	struct schib schib;
	struct subchannel *sch;

	sch = get_subchannel_by_schid(schid);
	if (sch) {
		put_device(&sch->dev);
		return 0;
	}
	if (stsch_err(schid, &schib))
		/* We're through */
		return -ENXIO;
	/* Put it on the slow path. */
	if (css_enqueue_subchannel_slow(schid)) {
		css_clear_subchannel_slow_list();
		need_rescan = 1;
		return -EAGAIN;
	}
	return 0;
}

/*
 * Function: s390_vary_chpid
 * Varies the specified chpid online or offline
 */
static int
s390_vary_chpid( __u8 chpid, int on)
{
	char dbf_text[15];
	int status;

	sprintf(dbf_text, on?"varyon%x":"varyoff%x", chpid);
	CIO_TRACE_EVENT( 2, dbf_text);

	status = get_chp_status(chpid);
	if (status < 0) {
		printk(KERN_ERR "Can't vary unknown chpid %02X\n", chpid);
		return -EINVAL;
	}

	if (!on && !status) {
		printk(KERN_ERR "chpid %x is already offline\n", chpid);
		return -EINVAL;
	}

	set_chp_logically_online(chpid, on);

	/*
	 * Redo PathVerification on the devices the chpid connects to
	 */

	bus_for_each_dev(&css_bus_type, NULL, &chpid, on ?
			 s390_subchannel_vary_chpid_on :
			 s390_subchannel_vary_chpid_off);
	if (on)
		/* Scan for new devices on varied on path. */
		for_each_subchannel(__s390_vary_chpid_on, NULL);
	if (need_rescan || css_slow_subchannels_exist())
		queue_work(slow_path_wq, &slow_path_work);
	return 0;
}

/*
 * Channel measurement related functions
 */
static ssize_t
chp_measurement_chars_read(struct kobject *kobj, char *buf, loff_t off,
			   size_t count)
{
	struct channel_path *chp;
	unsigned int size;

	chp = to_channelpath(container_of(kobj, struct device, kobj));
	if (!chp->cmg_chars)
		return 0;

	size = sizeof(struct cmg_chars);

	if (off > size)
		return 0;
	if (off + count > size)
		count = size - off;
	memcpy(buf, chp->cmg_chars + off, count);
	return count;
}

static struct bin_attribute chp_measurement_chars_attr = {
	.attr = {
		.name = "measurement_chars",
		.mode = S_IRUSR,
		.owner = THIS_MODULE,
	},
	.size = sizeof(struct cmg_chars),
	.read = chp_measurement_chars_read,
};

static void
chp_measurement_copy_block(struct cmg_entry *buf,
			   struct channel_subsystem *css, int chpid)
{
	void *area;
	struct cmg_entry *entry, reference_buf;
	int idx;

	if (chpid < 128) {
		area = css->cub_addr1;
		idx = chpid;
	} else {
		area = css->cub_addr2;
		idx = chpid - 128;
	}
	entry = area + (idx * sizeof(struct cmg_entry));
	do {
		memcpy(buf, entry, sizeof(*entry));
		memcpy(&reference_buf, entry, sizeof(*entry));
	} while (reference_buf.values[0] != buf->values[0]);
}

static ssize_t
chp_measurement_read(struct kobject *kobj, char *buf, loff_t off, size_t count)
{
	struct channel_path *chp;
	struct channel_subsystem *css;
	unsigned int size;

	chp = to_channelpath(container_of(kobj, struct device, kobj));
	css = to_css(chp->dev.parent);

	size = sizeof(struct cmg_chars);

	/* Only allow single reads. */
	if (off || count < size)
		return 0;
	chp_measurement_copy_block((struct cmg_entry *)buf, css, chp->id);
	return count;
}

static struct bin_attribute chp_measurement_attr = {
	.attr = {
		.name = "measurement",
		.mode = S_IRUSR,
		.owner = THIS_MODULE,
	},
	.size = sizeof(struct cmg_entry),
	.read = chp_measurement_read,
};

static void
chsc_remove_chp_cmg_attr(struct channel_path *chp)
{
	sysfs_remove_bin_file(&chp->dev.kobj, &chp_measurement_chars_attr);
	sysfs_remove_bin_file(&chp->dev.kobj, &chp_measurement_attr);
}

static int
chsc_add_chp_cmg_attr(struct channel_path *chp)
{
	int ret;

	ret = sysfs_create_bin_file(&chp->dev.kobj,
				    &chp_measurement_chars_attr);
	if (ret)
		return ret;
	ret = sysfs_create_bin_file(&chp->dev.kobj, &chp_measurement_attr);
	if (ret)
		sysfs_remove_bin_file(&chp->dev.kobj,
				      &chp_measurement_chars_attr);
	return ret;
}

static void
chsc_remove_cmg_attr(struct channel_subsystem *css)
{
	int i;

	for (i = 0; i <= __MAX_CHPID; i++) {
		if (!css->chps[i])
			continue;
		chsc_remove_chp_cmg_attr(css->chps[i]);
	}
}

static int
chsc_add_cmg_attr(struct channel_subsystem *css)
{
	int i, ret;

	ret = 0;
	for (i = 0; i <= __MAX_CHPID; i++) {
		if (!css->chps[i])
			continue;
		ret = chsc_add_chp_cmg_attr(css->chps[i]);
		if (ret)
			goto cleanup;
	}
	return ret;
cleanup:
	for (--i; i >= 0; i--) {
		if (!css->chps[i])
			continue;
		chsc_remove_chp_cmg_attr(css->chps[i]);
	}
	return ret;
}


static int
__chsc_do_secm(struct channel_subsystem *css, int enable, void *page)
{
	struct {
		struct chsc_header request;
		u32 operation_code : 2;
		u32 : 30;
		u32 key : 4;
		u32 : 28;
		u32 zeroes1;
		u32 cub_addr1;
		u32 zeroes2;
		u32 cub_addr2;
		u32 reserved[13];
		struct chsc_header response;
		u32 status : 8;
		u32 : 4;
		u32 fmt : 4;
		u32 : 16;
	} *secm_area;
	int ret, ccode;

	secm_area = page;
	secm_area->request.length = 0x0050;
	secm_area->request.code = 0x0016;

	secm_area->key = PAGE_DEFAULT_KEY;
	secm_area->cub_addr1 = (u64)(unsigned long)css->cub_addr1;
	secm_area->cub_addr2 = (u64)(unsigned long)css->cub_addr2;

	secm_area->operation_code = enable ? 0 : 1;

	ccode = chsc(secm_area);
	if (ccode > 0)
		return (ccode == 3) ? -ENODEV : -EBUSY;

	switch (secm_area->response.code) {
	case 0x0001: /* Success. */
		ret = 0;
		break;
	case 0x0003: /* Invalid block. */
	case 0x0007: /* Invalid format. */
	case 0x0008: /* Other invalid block. */
		CIO_CRW_EVENT(2, "Error in chsc request block!\n");
		ret = -EINVAL;
		break;
	case 0x0004: /* Command not provided in model. */
		CIO_CRW_EVENT(2, "Model does not provide secm\n");
		ret = -EOPNOTSUPP;
		break;
	case 0x0102: /* cub adresses incorrect */
		CIO_CRW_EVENT(2, "Invalid addresses in chsc request block\n");
		ret = -EINVAL;
		break;
	case 0x0103: /* key error */
		CIO_CRW_EVENT(2, "Access key error in secm\n");
		ret = -EINVAL;
		break;
	case 0x0105: /* error while starting */
		CIO_CRW_EVENT(2, "Error while starting channel measurement\n");