/*
   *   S/390 common I/O routines -- channel subsystem call
   *
   *    Copyright IBM Corp. 1999,2012
   *    Author(s): Ingo Adlung (adlung@de.ibm.com)
   *		 Cornelia Huck (cornelia.huck@de.ibm.com)
   *		 Arnd Bergmann (arndb@de.ibm.com)
   */
  
  #define KMSG_COMPONENT "cio"
  #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  
  #include <linux/module.h>
  #include <linux/slab.h>
  #include <linux/init.h>
  #include <linux/device.h>
  #include <linux/pci.h>
  
  #include <asm/cio.h>
  #include <asm/chpid.h>
  #include <asm/chsc.h>
  #include <asm/crw.h>
  #include <asm/isc.h>
  
  #include "css.h"
  #include "cio.h"
  #include "cio_debug.h"
  #include "ioasm.h"
  #include "chp.h"
  #include "chsc.h"
  
  static void *sei_page;
  static void *chsc_page;
  static DEFINE_SPINLOCK(chsc_page_lock);
  
  /**
   * chsc_error_from_response() - convert a chsc response to an error
   * @response: chsc response code
   *
   * Returns an appropriate Linux error code for @response.
   */
  int chsc_error_from_response(int response)
  {
  	switch (response) {
  	case 0x0001:
  		return 0;
  	case 0x0002:
  	case 0x0003:
  	case 0x0006:
  	case 0x0007:
  	case 0x0008:
  	case 0x000a:
  	case 0x0104:
  		return -EINVAL;
  	case 0x0004:
  		return -EOPNOTSUPP;
  	case 0x000b:
  	case 0x0107:		/* "Channel busy" for the op 0x003d */
  		return -EBUSY;
  	case 0x0100:
  	case 0x0102:
  		return -ENOMEM;
  	default:
  		return -EIO;
  	}
  }
  EXPORT_SYMBOL_GPL(chsc_error_from_response);
  
  struct chsc_ssd_area {
  	struct chsc_header request;
  	u16 :10;
  	u16 ssid:2;
  	u16 :4;
  	u16 f_sch;	  /* first subchannel */
  	u16 :16;
  	u16 l_sch;	  /* last subchannel */
  	u32 :32;
  	struct chsc_header response;
  	u32 :32;
  	u8 sch_valid : 1;
  	u8 dev_valid : 1;
  	u8 st	     : 3; /* subchannel type */
  	u8 zeroes    : 3;
  	u8  unit_addr;	  /* unit address */
  	u16 devno;	  /* device number */
  	u8 path_mask;
  	u8 fla_valid_mask;
  	u16 sch;	  /* subchannel */
  	u8 chpid[8];	  /* chpids 0-7 */
  	u16 fla[8];	  /* full link addresses 0-7 */
  } __attribute__ ((packed));
  
  int chsc_get_ssd_info(struct subchannel_id schid, struct chsc_ssd_info *ssd)
  {
  	struct chsc_ssd_area *ssd_area;
  	int ccode;
  	int ret;
  	int i;
  	int mask;
  
  	spin_lock_irq(&chsc_page_lock);
  	memset(chsc_page, 0, PAGE_SIZE);
  	ssd_area = chsc_page;
  	ssd_area->request.length = 0x0010;
  	ssd_area->request.code = 0x0004;
  	ssd_area->ssid = schid.ssid;
  	ssd_area->f_sch = schid.sch_no;
  	ssd_area->l_sch = schid.sch_no;
  
  	ccode = chsc(ssd_area);
  	/* Check response. */
  	if (ccode > 0) {
  		ret = (ccode == 3) ? -ENODEV : -EBUSY;
  		goto out;
  	}
  	ret = chsc_error_from_response(ssd_area->response.code);
  	if (ret != 0) {
  		CIO_MSG_EVENT(2, "chsc: ssd failed for 0.%x.%04x (rc=%04x)
  ",
  			      schid.ssid, schid.sch_no,
  			      ssd_area->response.code);
  		goto out;
  	}
  	if (!ssd_area->sch_valid) {
  		ret = -ENODEV;
  		goto out;
  	}
  	/* Copy data */
  	ret = 0;
  	memset(ssd, 0, sizeof(struct chsc_ssd_info));
  	if ((ssd_area->st != SUBCHANNEL_TYPE_IO) &&
  	    (ssd_area->st != SUBCHANNEL_TYPE_MSG))
  		goto out;
  	ssd->path_mask = ssd_area->path_mask;
  	ssd->fla_valid_mask = ssd_area->fla_valid_mask;
  	for (i = 0; i < 8; i++) {
  		mask = 0x80 >> i;
  		if (ssd_area->path_mask & mask) {
  			chp_id_init(&ssd->chpid[i]);
  			ssd->chpid[i].id = ssd_area->chpid[i];
  		}
  		if (ssd_area->fla_valid_mask & mask)
  			ssd->fla[i] = ssd_area->fla[i];
  	}
  out:
  	spin_unlock_irq(&chsc_page_lock);
  	return ret;
  }
  
  /**
   * chsc_ssqd() - store subchannel QDIO data (SSQD)
   * @schid: id of the subchannel on which SSQD is performed
   * @ssqd: request and response block for SSQD
   *
   * Returns 0 on success.
   */
  int chsc_ssqd(struct subchannel_id schid, struct chsc_ssqd_area *ssqd)
  {
  	memset(ssqd, 0, sizeof(*ssqd));
  	ssqd->request.length = 0x0010;
  	ssqd->request.code = 0x0024;
  	ssqd->first_sch = schid.sch_no;
  	ssqd->last_sch = schid.sch_no;
  	ssqd->ssid = schid.ssid;
  
  	if (chsc(ssqd))
  		return -EIO;
  
  	return chsc_error_from_response(ssqd->response.code);
  }
  EXPORT_SYMBOL_GPL(chsc_ssqd);
  
  /**
   * chsc_sadc() - set adapter device controls (SADC)
   * @schid: id of the subchannel on which SADC is performed
   * @scssc: request and response block for SADC
   * @summary_indicator_addr: summary indicator address
   * @subchannel_indicator_addr: subchannel indicator address
   *
   * Returns 0 on success.
   */
  int chsc_sadc(struct subchannel_id schid, struct chsc_scssc_area *scssc,
  	      u64 summary_indicator_addr, u64 subchannel_indicator_addr)
  {
  	memset(scssc, 0, sizeof(*scssc));
  	scssc->request.length = 0x0fe0;
  	scssc->request.code = 0x0021;
  	scssc->operation_code = 0;
  
  	scssc->summary_indicator_addr = summary_indicator_addr;
  	scssc->subchannel_indicator_addr = subchannel_indicator_addr;
  
  	scssc->ks = PAGE_DEFAULT_KEY >> 4;
  	scssc->kc = PAGE_DEFAULT_KEY >> 4;
  	scssc->isc = QDIO_AIRQ_ISC;
  	scssc->schid = schid;
  
  	/* enable the time delay disablement facility */
  	if (css_general_characteristics.aif_tdd)
  		scssc->word_with_d_bit = 0x10000000;
  
  	if (chsc(scssc))
  		return -EIO;
  
  	return chsc_error_from_response(scssc->response.code);
  }
  EXPORT_SYMBOL_GPL(chsc_sadc);
  
  static int s390_subchannel_remove_chpid(struct subchannel *sch, void *data)
  {
  	spin_lock_irq(sch->lock);
  	if (sch->driver && sch->driver->chp_event)
  		if (sch->driver->chp_event(sch, data, CHP_OFFLINE) != 0)
  			goto out_unreg;
  	spin_unlock_irq(sch->lock);
  	return 0;
  
  out_unreg:
  	sch->lpm = 0;
  	spin_unlock_irq(sch->lock);
  	css_schedule_eval(sch->schid);
  	return 0;
  }
  
  void chsc_chp_offline(struct chp_id chpid)
  {
  	char dbf_txt[15];
  	struct chp_link link;
  
  	sprintf(dbf_txt, "chpr%x.%02x", chpid.cssid, chpid.id);
  	CIO_TRACE_EVENT(2, dbf_txt);
  
  	if (chp_get_status(chpid) <= 0)
  		return;
  	memset(&link, 0, sizeof(struct chp_link));
  	link.chpid = chpid;
  	/* Wait until previous actions have settled. */
  	css_wait_for_slow_path();
  	for_each_subchannel_staged(s390_subchannel_remove_chpid, NULL, &link);
  }
  
  static int __s390_process_res_acc(struct subchannel *sch, void *data)
  {
  	spin_lock_irq(sch->lock);
  	if (sch->driver && sch->driver->chp_event)
  		sch->driver->chp_event(sch, data, CHP_ONLINE);
  	spin_unlock_irq(sch->lock);
  
  	return 0;
  }
  
  static void s390_process_res_acc(struct chp_link *link)
  {
  	char dbf_txt[15];
  
  	sprintf(dbf_txt, "accpr%x.%02x", link->chpid.cssid,
  		link->chpid.id);
  	CIO_TRACE_EVENT( 2, dbf_txt);
  	if (link->fla != 0) {
  		sprintf(dbf_txt, "fla%x", link->fla);
  		CIO_TRACE_EVENT( 2, dbf_txt);
  	}
  	/* Wait until previous actions have settled. */
  	css_wait_for_slow_path();
  	/*
  	 * I/O resources may have become accessible.
  	 * Scan through all subchannels that may be concerned and
  	 * do a validation on those.
  	 * The more information we have (info), the less scanning
  	 * will we have to do.
  	 */
  	for_each_subchannel_staged(__s390_process_res_acc, NULL, link);
  	css_schedule_reprobe();
  }
  
  static int
  __get_chpid_from_lir(void *data)
  {
  	struct lir {
  		u8  iq;
  		u8  ic;
  		u16 sci;
  		/* incident-node descriptor */
  		u32 indesc[28];
  		/* attached-node descriptor */
  		u32 andesc[28];
  		/* incident-specific information */
  		u32 isinfo[28];
  	} __attribute__ ((packed)) *lir;
  
  	lir = data;
  	if (!(lir->iq&0x80))
  		/* NULL link incident record */
  		return -EINVAL;
  	if (!(lir->indesc[0]&0xc0000000))
  		/* node descriptor not valid */
  		return -EINVAL;
  	if (!(lir->indesc[0]&0x10000000))
  		/* don't handle device-type nodes - FIXME */
  		return -EINVAL;
  	/* Byte 3 contains the chpid. Could also be CTCA, but we don't care */
  
  	return (u16) (lir->indesc[0]&0x000000ff);
  }
  
  struct chsc_sei_nt0_area {
  	u8  flags;
  	u8  vf;				/* validity flags */
  	u8  rs;				/* reporting source */
  	u8  cc;				/* content code */
  	u16 fla;			/* full link address */
  	u16 rsid;			/* reporting source id */
  	u32 reserved1;
  	u32 reserved2;
  	/* ccdf has to be big enough for a link-incident record */
  	u8  ccdf[PAGE_SIZE - 24 - 16];	/* content-code dependent field */
  } __packed;
  
  struct chsc_sei_nt2_area {
  	u8  flags;			/* p and v bit */
  	u8  reserved1;
  	u8  reserved2;
  	u8  cc;				/* content code */
  	u32 reserved3[13];
  	u8  ccdf[PAGE_SIZE - 24 - 56];	/* content-code dependent field */
  } __packed;
  
  #define CHSC_SEI_NT0	(1ULL << 63)
  #define CHSC_SEI_NT2	(1ULL << 61)
  
  struct chsc_sei {
  	struct chsc_header request;
  	u32 reserved1;
  	u64 ntsm;			/* notification type mask */
  	struct chsc_header response;
  	u32 :24;
  	u8 nt;
  	union {
  		struct chsc_sei_nt0_area nt0_area;
  		struct chsc_sei_nt2_area nt2_area;
  		u8 nt_area[PAGE_SIZE - 24];
  	} u;
  } __packed;
  
  static void chsc_process_sei_link_incident(struct chsc_sei_nt0_area *sei_area)
  {
  	struct chp_id chpid;
  	int id;
  
  	CIO_CRW_EVENT(4, "chsc: link incident (rs=%02x, rs_id=%04x)
  ",
  		      sei_area->rs, sei_area->rsid);
  	if (sei_area->rs != 4)
  		return;
  	id = __get_chpid_from_lir(sei_area->ccdf);
  	if (id < 0)
  		CIO_CRW_EVENT(4, "chsc: link incident - invalid LIR
  ");
  	else {
  		chp_id_init(&chpid);
  		chpid.id = id;
  		chsc_chp_offline(chpid);
  	}
  }
  
  static void chsc_process_sei_res_acc(struct chsc_sei_nt0_area *sei_area)
  {
  	struct chp_link link;
  	struct chp_id chpid;
  	int status;
  
  	CIO_CRW_EVENT(4, "chsc: resource accessibility event (rs=%02x, "
  		      "rs_id=%04x)
  ", sei_area->rs, sei_area->rsid);
  	if (sei_area->rs != 4)
  		return;
  	chp_id_init(&chpid);
  	chpid.id = sei_area->rsid;
  	/* allocate a new channel path structure, if needed */
  	status = chp_get_status(chpid);
  	if (status < 0)
  		chp_new(chpid);
  	else if (!status)
  		return;
  	memset(&link, 0, sizeof(struct chp_link));
  	link.chpid = chpid;
  	if ((sei_area->vf & 0xc0) != 0) {
  		link.fla = sei_area->fla;
  		if ((sei_area->vf & 0xc0) == 0xc0)
  			/* full link address */
  			link.fla_mask = 0xffff;
  		else
  			/* link address */
  			link.fla_mask = 0xff00;
  	}
  	s390_process_res_acc(&link);
  }
  
  static void chsc_process_sei_chp_avail(struct chsc_sei_nt0_area *sei_area)
  {
  	struct channel_path *chp;
  	struct chp_id chpid;
  	u8 *data;
  	int num;
  
  	CIO_CRW_EVENT(4, "chsc: channel path availability information
  ");
  	if (sei_area->rs != 0)
  		return;
  	data = sei_area->ccdf;
  	chp_id_init(&chpid);
  	for (num = 0; num <= __MAX_CHPID; num++) {
  		if (!chp_test_bit(data, num))
  			continue;
  		chpid.id = num;
  
  		CIO_CRW_EVENT(4, "Update information for channel path "
  			      "%x.%02x
  ", chpid.cssid, chpid.id);
  		chp = chpid_to_chp(chpid);
  		if (!chp) {
  			chp_new(chpid);
  			continue;
  		}
  		mutex_lock(&chp->lock);
  		chp_update_desc(chp);
  		mutex_unlock(&chp->lock);
  	}
  }
  
  struct chp_config_data {
  	u8 map[32];
  	u8 op;
  	u8 pc;
  };
  
  static void chsc_process_sei_chp_config(struct chsc_sei_nt0_area *sei_area)
  {
  	struct chp_config_data *data;
  	struct chp_id chpid;
  	int num;
  	char *events[3] = {"configure", "deconfigure", "cancel deconfigure"};
  
  	CIO_CRW_EVENT(4, "chsc: channel-path-configuration notification
  ");
  	if (sei_area->rs != 0)
  		return;
  	data = (struct chp_config_data *) &(sei_area->ccdf);
  	chp_id_init(&chpid);
  	for (num = 0; num <= __MAX_CHPID; num++) {
  		if (!chp_test_bit(data->map, num))
  			continue;
  		chpid.id = num;
  		pr_notice("Processing %s for channel path %x.%02x
  ",
  			  events[data->op], chpid.cssid, chpid.id);
  		switch (data->op) {
  		case 0:
  			chp_cfg_schedule(chpid, 1);
  			break;
  		case 1:
  			chp_cfg_schedule(chpid, 0);
  			break;
  		case 2:
  			chp_cfg_cancel_deconfigure(chpid);
  			break;
  		}
  	}
  }
  
  static void chsc_process_sei_scm_change(struct chsc_sei_nt0_area *sei_area)
  {
  	int ret;
  
  	CIO_CRW_EVENT(4, "chsc: scm change notification
  ");
  	if (sei_area->rs != 7)
  		return;
  
  	ret = scm_update_information();
  	if (ret)
  		CIO_CRW_EVENT(0, "chsc: updating change notification"
  			      " failed (rc=%d).
  ", ret);
  }
  
  static void chsc_process_sei_scm_avail(struct chsc_sei_nt0_area *sei_area)
  {
  	int ret;
  
  	CIO_CRW_EVENT(4, "chsc: scm available information
  ");
  	if (sei_area->rs != 7)
  		return;
  
  	ret = scm_process_availability_information();
  	if (ret)
  		CIO_CRW_EVENT(0, "chsc: process availability information"
  			      " failed (rc=%d).
  ", ret);
  }
  
  static void chsc_process_sei_nt2(struct chsc_sei_nt2_area *sei_area)
  {
  	switch (sei_area->cc) {
  	case 1:
  		zpci_event_error(sei_area->ccdf);
  		break;
  	case 2:
  		zpci_event_availability(sei_area->ccdf);
  		break;
  	default:
  		CIO_CRW_EVENT(2, "chsc: sei nt2 unhandled cc=%d
  ",
  			      sei_area->cc);
  		break;
  	}
  }
  
  static void chsc_process_sei_nt0(struct chsc_sei_nt0_area *sei_area)
  {
  	/* which kind of information was stored? */
  	switch (sei_area->cc) {
  	case 1: /* link incident*/
  		chsc_process_sei_link_incident(sei_area);
  		break;
  	case 2: /* i/o resource accessibility */
  		chsc_process_sei_res_acc(sei_area);
  		break;
  	case 7: /* channel-path-availability information */
  		chsc_process_sei_chp_avail(sei_area);
  		break;
  	case 8: /* channel-path-configuration notification */
  		chsc_process_sei_chp_config(sei_area);
  		break;
  	case 12: /* scm change notification */
  		chsc_process_sei_scm_change(sei_area);
  		break;
  	case 14: /* scm available notification */
  		chsc_process_sei_scm_avail(sei_area);
  		break;
  	default: /* other stuff */
  		CIO_CRW_EVENT(2, "chsc: sei nt0 unhandled cc=%d
  ",
  			      sei_area->cc);
  		break;
  	}
  
  	/* Check if we might have lost some information. */
  	if (sei_area->flags & 0x40) {
  		CIO_CRW_EVENT(2, "chsc: event overflow
  ");
  		css_schedule_eval_all();
  	}
  }
  
  static void chsc_process_event_information(struct chsc_sei *sei, u64 ntsm)
  {
  	static int ntsm_unsupported;
  
  	while (true) {
  		memset(sei, 0, sizeof(*sei));
  		sei->request.length = 0x0010;
  		sei->request.code = 0x000e;
  		if (!ntsm_unsupported)
  			sei->ntsm = ntsm;
  
  		if (chsc(sei))
  			break;
  
  		if (sei->response.code != 0x0001) {
  			CIO_CRW_EVENT(2, "chsc: sei failed (rc=%04x, ntsm=%llx)
  ",
  				      sei->response.code, sei->ntsm);
  
  			if (sei->response.code == 3 && sei->ntsm) {
  				/* Fallback for old firmware. */
  				ntsm_unsupported = 1;
  				continue;
  			}
  			break;
  		}
  
  		CIO_CRW_EVENT(2, "chsc: sei successful (nt=%d)
  ", sei->nt);
  		switch (sei->nt) {
  		case 0:
  			chsc_process_sei_nt0(&sei->u.nt0_area);
  			break;
  		case 2:
  			chsc_process_sei_nt2(&sei->u.nt2_area);
  			break;
  		default:
  			CIO_CRW_EVENT(2, "chsc: unhandled nt: %d
  ", sei->nt);
  			break;
  		}
  
  		if (!(sei->u.nt0_area.flags & 0x80))
  			break;
  	}
  }
  
  /*
   * Handle channel subsystem related CRWs.
   * Use store event information to find out what's going on.
   *
   * Note: Access to sei_page is serialized through machine check handler
   * thread, so no need for locking.
   */
  static void chsc_process_crw(struct crw *crw0, struct crw *crw1, int overflow)
  {
  	struct chsc_sei *sei = sei_page;
  
  	if (overflow) {
  		css_schedule_eval_all();
  		return;
  	}
  	CIO_CRW_EVENT(2, "CRW reports slct=%d, oflw=%d, "
  		      "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X
  ",
  		      crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
  		      crw0->erc, crw0->rsid);
  
  	CIO_TRACE_EVENT(2, "prcss");
  	chsc_process_event_information(sei, CHSC_SEI_NT0 | CHSC_SEI_NT2);
  }
  
  void chsc_chp_online(struct chp_id chpid)
  {
  	char dbf_txt[15];
  	struct chp_link link;
  
  	sprintf(dbf_txt, "cadd%x.%02x", chpid.cssid, chpid.id);
  	CIO_TRACE_EVENT(2, dbf_txt);
  
  	if (chp_get_status(chpid) != 0) {
  		memset(&link, 0, sizeof(struct chp_link));
  		link.chpid = chpid;
  		/* Wait until previous actions have settled. */
  		css_wait_for_slow_path();
  		for_each_subchannel_staged(__s390_process_res_acc, NULL,
  					   &link);
  		css_schedule_reprobe();
  	}
  }
  
  static void __s390_subchannel_vary_chpid(struct subchannel *sch,
  					 struct chp_id chpid, int on)
  {
  	unsigned long flags;
  	struct chp_link link;
  
  	memset(&link, 0, sizeof(struct chp_link));
  	link.chpid = chpid;
  	spin_lock_irqsave(sch->lock, flags);
  	if (sch->driver && sch->driver->chp_event)
  		sch->driver->chp_event(sch, &link,
  				       on ? CHP_VARY_ON : CHP_VARY_OFF);
  	spin_unlock_irqrestore(sch->lock, flags);
  }
  
  static int s390_subchannel_vary_chpid_off(struct subchannel *sch, void *data)
  {
  	struct chp_id *chpid = data;
  
  	__s390_subchannel_vary_chpid(sch, *chpid, 0);
  	return 0;
  }
  
  static int s390_subchannel_vary_chpid_on(struct subchannel *sch, void *data)
  {
  	struct chp_id *chpid = data;
  
  	__s390_subchannel_vary_chpid(sch, *chpid, 1);
  	return 0;
  }
  
  /**
   * chsc_chp_vary - propagate channel-path vary operation to subchannels
   * @chpid: channl-path ID
   * @on: non-zero for vary online, zero for vary offline
   */
  int chsc_chp_vary(struct chp_id chpid, int on)
  {
  	struct channel_path *chp = chpid_to_chp(chpid);
  
  	/* Wait until previous actions have settled. */
  	css_wait_for_slow_path();
  	/*
  	 * Redo PathVerification on the devices the chpid connects to
  	 */
  	if (on) {
  		/* Try to update the channel path description. */
  		chp_update_desc(chp);
  		for_each_subchannel_staged(s390_subchannel_vary_chpid_on,
  					   NULL, &chpid);
  		css_schedule_reprobe();
  	} else
  		for_each_subchannel_staged(s390_subchannel_vary_chpid_off,
  					   NULL, &chpid);
  
  	return 0;
  }
  
  static void
  chsc_remove_cmg_attr(struct channel_subsystem *css)
  {
  	int i;
  
  	for (i = 0; i <= __MAX_CHPID; i++) {
  		if (!css->chps[i])
  			continue;
  		chp_remove_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 = chp_add_cmg_attr(css->chps[i]);
  		if (ret)
  			goto cleanup;
  	}
  	return ret;
  cleanup:
  	for (--i; i >= 0; i--) {
  		if (!css->chps[i])
  			continue;
  		chp_remove_cmg_attr(css->chps[i]);
  	}
  	return ret;
  }
  
  int __chsc_do_secm(struct channel_subsystem *css, int enable)
  {
  	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;
  	} __attribute__ ((packed)) *secm_area;
  	int ret, ccode;
  
  	spin_lock_irq(&chsc_page_lock);
  	memset(chsc_page, 0, PAGE_SIZE);
  	secm_area = chsc_page;
  	secm_area->request.length = 0x0050;
  	secm_area->request.code = 0x0016;
  
  	secm_area->key = PAGE_DEFAULT_KEY >> 4;
  	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) {
  		ret = (ccode == 3) ? -ENODEV : -EBUSY;
  		goto out;
  	}
  
  	switch (secm_area->response.code) {
  	case 0x0102:
  	case 0x0103:
  		ret = -EINVAL;
  		break;
  	default:
  		ret = chsc_error_from_response(secm_area->response.code);
  	}
  	if (ret != 0)
  		CIO_CRW_EVENT(2, "chsc: secm failed (rc=%04x)
  ",
  			      secm_area->response.code);
  out:
  	spin_unlock_irq(&chsc_page_lock);
  	return ret;
  }
  
  int
  chsc_secm(struct channel_subsystem *css, int enable)
  {
  	int ret;
  
  	if (enable && !css->cm_enabled) {
  		css->cub_addr1 = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
  		css->cub_addr2 = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
  		if (!css->cub_addr1 || !css->cub_addr2) {
  			free_page((unsigned long)css->cub_addr1);
  			free_page((unsigned long)css->cub_addr2);
  			return -ENOMEM;
  		}
  	}
  	ret = __chsc_do_secm(css, enable);
  	if (!ret) {
  		css->cm_enabled = enable;
  		if (css->cm_enabled) {
  			ret = chsc_add_cmg_attr(css);
  			if (ret) {
  				__chsc_do_secm(css, 0);
  				css->cm_enabled = 0;
  			}
  		} else
  			chsc_remove_cmg_attr(css);
  	}
  	if (!css->cm_enabled) {
  		free_page((unsigned long)css->cub_addr1);
  		free_page((unsigned long)css->cub_addr2);
  	}
  	return ret;
  }
  
  int chsc_determine_channel_path_desc(struct chp_id chpid, int fmt, int rfmt,
  				     int c, int m, void *page)
  {
  	struct chsc_scpd *scpd_area;
  	int ccode, ret;
  
  	if ((rfmt == 1) && !css_general_characteristics.fcs)
  		return -EINVAL;
  	if ((rfmt == 2) && !css_general_characteristics.cib)
  		return -EINVAL;
  
  	memset(page, 0, PAGE_SIZE);
  	scpd_area = page;
  	scpd_area->request.length = 0x0010;
  	scpd_area->request.code = 0x0002;
  	scpd_area->cssid = chpid.cssid;
  	scpd_area->first_chpid = chpid.id;
  	scpd_area->last_chpid = chpid.id;
  	scpd_area->m = m;
  	scpd_area->c = c;
  	scpd_area->fmt = fmt;
  	scpd_area->rfmt = rfmt;
  
  	ccode = chsc(scpd_area);
  	if (ccode > 0)
  		return (ccode == 3) ? -ENODEV : -EBUSY;
  
  	ret = chsc_error_from_response(scpd_area->response.code);
  	if (ret)
  		CIO_CRW_EVENT(2, "chsc: scpd failed (rc=%04x)
  ",
  			      scpd_area->response.code);
  	return ret;
  }
  EXPORT_SYMBOL_GPL(chsc_determine_channel_path_desc);
  
  int chsc_determine_base_channel_path_desc(struct chp_id chpid,
  					  struct channel_path_desc *desc)
  {
  	struct chsc_response_struct *chsc_resp;
  	struct chsc_scpd *scpd_area;
  	unsigned long flags;
  	int ret;
  
  	spin_lock_irqsave(&chsc_page_lock, flags);
  	scpd_area = chsc_page;
  	ret = chsc_determine_channel_path_desc(chpid, 0, 0, 0, 0, scpd_area);
  	if (ret)
  		goto out;
  	chsc_resp = (void *)&scpd_area->response;
  	memcpy(desc, &chsc_resp->data, sizeof(*desc));
  out:
  	spin_unlock_irqrestore(&chsc_page_lock, flags);
  	return ret;
  }
  
  int chsc_determine_fmt1_channel_path_desc(struct chp_id chpid,
  					  struct channel_path_desc_fmt1 *desc)
  {
  	struct chsc_response_struct *chsc_resp;
  	struct chsc_scpd *scpd_area;
  	unsigned long flags;
  	int ret;
  
  	spin_lock_irqsave(&chsc_page_lock, flags);
  	scpd_area = chsc_page;
  	ret = chsc_determine_channel_path_desc(chpid, 0, 0, 1, 0, scpd_area);
  	if (ret)
  		goto out;
  	chsc_resp = (void *)&scpd_area->response;
  	memcpy(desc, &chsc_resp->data, sizeof(*desc));
  out:
  	spin_unlock_irqrestore(&chsc_page_lock, flags);
  	return ret;
  }
  
  static void
  chsc_initialize_cmg_chars(struct channel_path *chp, u8 cmcv,
  			  struct cmg_chars *chars)
  {
  	struct cmg_chars *cmg_chars;
  	int i, mask;
  
  	cmg_chars = chp->cmg_chars;
  	for (i = 0; i < NR_MEASUREMENT_CHARS; i++) {
  		mask = 0x80 >> (i + 3);
  		if (cmcv & mask)
  			cmg_chars->values[i] = chars->values[i];
  		else
  			cmg_chars->values[i] = 0;
  	}
  }
  
  int chsc_get_channel_measurement_chars(struct channel_path *chp)
  {
  	struct cmg_chars *cmg_chars;
  	int ccode, ret;
  
  	struct {
  		struct chsc_header request;
  		u32 : 24;
  		u32 first_chpid : 8;
  		u32 : 24;
  		u32 last_chpid : 8;
  		u32 zeroes1;
  		struct chsc_header response;
  		u32 zeroes2;
  		u32 not_valid : 1;
  		u32 shared : 1;
  		u32 : 22;
  		u32 chpid : 8;
  		u32 cmcv : 5;
  		u32 : 11;
  		u32 cmgq : 8;
  		u32 cmg : 8;
  		u32 zeroes3;
  		u32 data[NR_MEASUREMENT_CHARS];
  	} __attribute__ ((packed)) *scmc_area;
  
  	chp->cmg_chars = NULL;
  	cmg_chars = kmalloc(sizeof(*cmg_chars), GFP_KERNEL);
  	if (!cmg_chars)
  		return -ENOMEM;
  
  	spin_lock_irq(&chsc_page_lock);
  	memset(chsc_page, 0, PAGE_SIZE);
  	scmc_area = chsc_page;
  	scmc_area->request.length = 0x0010;
  	scmc_area->request.code = 0x0022;
  	scmc_area->first_chpid = chp->chpid.id;
  	scmc_area->last_chpid = chp->chpid.id;
  
  	ccode = chsc(scmc_area);
  	if (ccode > 0) {
  		ret = (ccode == 3) ? -ENODEV : -EBUSY;
  		goto out;
  	}
  
  	ret = chsc_error_from_response(scmc_area->response.code);
  	if (ret) {
  		CIO_CRW_EVENT(2, "chsc: scmc failed (rc=%04x)
  ",
  			      scmc_area->response.code);
  		goto out;
  	}
  	if (scmc_area->not_valid) {
  		chp->cmg = -1;
  		chp->shared = -1;
  		goto out;
  	}
  	chp->cmg = scmc_area->cmg;
  	chp->shared = scmc_area->shared;
  	if (chp->cmg != 2 && chp->cmg != 3) {
  		/* No cmg-dependent data. */
  		goto out;
  	}
  	chp->cmg_chars = cmg_chars;
  	chsc_initialize_cmg_chars(chp, scmc_area->cmcv,
  				  (struct cmg_chars *) &scmc_area->data);
  out:
  	spin_unlock_irq(&chsc_page_lock);
  	if (!chp->cmg_chars)
  		kfree(cmg_chars);
  
  	return ret;
  }
  
  int __init chsc_init(void)
  {
  	int ret;
  
  	sei_page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
  	chsc_page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
  	if (!sei_page || !chsc_page) {
  		ret = -ENOMEM;
  		goto out_err;
  	}
  	ret = crw_register_handler(CRW_RSC_CSS, chsc_process_crw);
  	if (ret)
  		goto out_err;
  	return ret;
  out_err:
  	free_page((unsigned long)chsc_page);
  	free_page((unsigned long)sei_page);
  	return ret;
  }
  
  void __init chsc_init_cleanup(void)
  {
  	crw_unregister_handler(CRW_RSC_CSS);
  	free_page((unsigned long)chsc_page);
  	free_page((unsigned long)sei_page);
  }
  
  int chsc_enable_facility(int operation_code)
  {
  	unsigned long flags;
  	int ret;
  	struct {
  		struct chsc_header request;
  		u8 reserved1:4;
  		u8 format:4;
  		u8 reserved2;
  		u16 operation_code;
  		u32 reserved3;
  		u32 reserved4;
  		u32 operation_data_area[252];
  		struct chsc_header response;
  		u32 reserved5:4;
  		u32 format2:4;
  		u32 reserved6:24;
  	} __attribute__ ((packed)) *sda_area;
  
  	spin_lock_irqsave(&chsc_page_lock, flags);
  	memset(chsc_page, 0, PAGE_SIZE);
  	sda_area = chsc_page;
  	sda_area->request.length = 0x0400;
  	sda_area->request.code = 0x0031;
  	sda_area->operation_code = operation_code;
  
  	ret = chsc(sda_area);
  	if (ret > 0) {
  		ret = (ret == 3) ? -ENODEV : -EBUSY;
  		goto out;
  	}
  
  	switch (sda_area->response.code) {
  	case 0x0101:
  		ret = -EOPNOTSUPP;
  		break;
  	default:
  		ret = chsc_error_from_response(sda_area->response.code);
  	}
  	if (ret != 0)
  		CIO_CRW_EVENT(2, "chsc: sda (oc=%x) failed (rc=%04x)
  ",
  			      operation_code, sda_area->response.code);
  out:
  	spin_unlock_irqrestore(&chsc_page_lock, flags);
  	return ret;
  }
  
  struct css_general_char css_general_characteristics;
  struct css_chsc_char css_chsc_characteristics;
  
  int __init
  chsc_determine_css_characteristics(void)
  {
  	int result;
  	struct {
  		struct chsc_header request;
  		u32 reserved1;
  		u32 reserved2;
  		u32 reserved3;
  		struct chsc_header response;
  		u32 reserved4;
  		u32 general_char[510];
  		u32 chsc_char[508];
  	} __attribute__ ((packed)) *scsc_area;
  
  	spin_lock_irq(&chsc_page_lock);
  	memset(chsc_page, 0, PAGE_SIZE);
  	scsc_area = chsc_page;
  	scsc_area->request.length = 0x0010;
  	scsc_area->request.code = 0x0010;
  
  	result = chsc(scsc_area);
  	if (result) {
  		result = (result == 3) ? -ENODEV : -EBUSY;
  		goto exit;
  	}
  
  	result = chsc_error_from_response(scsc_area->response.code);
  	if (result == 0) {
  		memcpy(&css_general_characteristics, scsc_area->general_char,
  		       sizeof(css_general_characteristics));
  		memcpy(&css_chsc_characteristics, scsc_area->chsc_char,
  		       sizeof(css_chsc_characteristics));
  	} else
  		CIO_CRW_EVENT(2, "chsc: scsc failed (rc=%04x)
  ",
  			      scsc_area->response.code);
  exit:
  	spin_unlock_irq(&chsc_page_lock);
  	return result;
  }
  
  EXPORT_SYMBOL_GPL(css_general_characteristics);
  EXPORT_SYMBOL_GPL(css_chsc_characteristics);
  
  int chsc_sstpc(void *page, unsigned int op, u16 ctrl)
  {
  	struct {
  		struct chsc_header request;
  		unsigned int rsvd0;
  		unsigned int op : 8;
  		unsigned int rsvd1 : 8;
  		unsigned int ctrl : 16;
  		unsigned int rsvd2[5];
  		struct chsc_header response;
  		unsigned int rsvd3[7];
  	} __attribute__ ((packed)) *rr;
  	int rc;
  
  	memset(page, 0, PAGE_SIZE);
  	rr = page;
  	rr->request.length = 0x0020;
  	rr->request.code = 0x0033;
  	rr->op = op;
  	rr->ctrl = ctrl;
  	rc = chsc(rr);
  	if (rc)
  		return -EIO;
  	rc = (rr->response.code == 0x0001) ? 0 : -EIO;
  	return rc;
  }
  
  int chsc_sstpi(void *page, void *result, size_t size)
  {
  	struct {
  		struct chsc_header request;
  		unsigned int rsvd0[3];
  		struct chsc_header response;
  		char data[size];
  	} __attribute__ ((packed)) *rr;
  	int rc;
  
  	memset(page, 0, PAGE_SIZE);
  	rr = page;
  	rr->request.length = 0x0010;
  	rr->request.code = 0x0038;
  	rc = chsc(rr);
  	if (rc)
  		return -EIO;
  	memcpy(result, &rr->data, size);
  	return (rr->response.code == 0x0001) ? 0 : -EIO;
  }
  
  int chsc_siosl(struct subchannel_id schid)
  {
  	struct {
  		struct chsc_header request;
  		u32 word1;
  		struct subchannel_id sid;
  		u32 word3;
  		struct chsc_header response;
  		u32 word[11];
  	} __attribute__ ((packed)) *siosl_area;
  	unsigned long flags;
  	int ccode;
  	int rc;
  
  	spin_lock_irqsave(&chsc_page_lock, flags);
  	memset(chsc_page, 0, PAGE_SIZE);
  	siosl_area = chsc_page;
  	siosl_area->request.length = 0x0010;
  	siosl_area->request.code = 0x0046;
  	siosl_area->word1 = 0x80000000;
  	siosl_area->sid = schid;
  
  	ccode = chsc(siosl_area);
  	if (ccode > 0) {
  		if (ccode == 3)
  			rc = -ENODEV;
  		else
  			rc = -EBUSY;
  		CIO_MSG_EVENT(2, "chsc: chsc failed for 0.%x.%04x (ccode=%d)
  ",
  			      schid.ssid, schid.sch_no, ccode);
  		goto out;
  	}
  	rc = chsc_error_from_response(siosl_area->response.code);
  	if (rc)
  		CIO_MSG_EVENT(2, "chsc: siosl failed for 0.%x.%04x (rc=%04x)
  ",
  			      schid.ssid, schid.sch_no,
  			      siosl_area->response.code);
  	else
  		CIO_MSG_EVENT(4, "chsc: siosl succeeded for 0.%x.%04x
  ",
  			      schid.ssid, schid.sch_no);
  out:
  	spin_unlock_irqrestore(&chsc_page_lock, flags);
  	return rc;
  }
  EXPORT_SYMBOL_GPL(chsc_siosl);
  
  /**
   * chsc_scm_info() - store SCM information (SSI)
   * @scm_area: request and response block for SSI
   * @token: continuation token
   *
   * Returns 0 on success.
   */
  int chsc_scm_info(struct chsc_scm_info *scm_area, u64 token)
  {
  	int ccode, ret;
  
  	memset(scm_area, 0, sizeof(*scm_area));
  	scm_area->request.length = 0x0020;
  	scm_area->request.code = 0x004C;
  	scm_area->reqtok = token;
  
  	ccode = chsc(scm_area);
  	if (ccode > 0) {
  		ret = (ccode == 3) ? -ENODEV : -EBUSY;
  		goto out;
  	}
  	ret = chsc_error_from_response(scm_area->response.code);
  	if (ret != 0)
  		CIO_MSG_EVENT(2, "chsc: scm info failed (rc=%04x)
  ",
  			      scm_area->response.code);
  out:
  	return ret;
  }
  EXPORT_SYMBOL_GPL(chsc_scm_info);
  
  /**
   * chsc_pnso_brinfo() - Perform Network-Subchannel Operation, Bridge Info.
   * @schid:		id of the subchannel on which PNSO is performed
   * @brinfo_area:	request and response block for the operation
   * @resume_token:	resume token for multiblock response
   * @cnc:		Boolean change-notification control
   *
   * brinfo_area must be allocated by the caller with get_zeroed_page(GFP_KERNEL)
   *
   * Returns 0 on success.
   */
  int chsc_pnso_brinfo(struct subchannel_id schid,
  		struct chsc_pnso_area *brinfo_area,
  		struct chsc_brinfo_resume_token resume_token,
  		int cnc)
  {
  	memset(brinfo_area, 0, sizeof(*brinfo_area));
  	brinfo_area->request.length = 0x0030;
  	brinfo_area->request.code = 0x003d; /* network-subchannel operation */
  	brinfo_area->m	   = schid.m;
  	brinfo_area->ssid  = schid.ssid;
  	brinfo_area->sch   = schid.sch_no;
  	brinfo_area->cssid = schid.cssid;
  	brinfo_area->oc    = 0; /* Store-network-bridging-information list */
  	brinfo_area->resume_token = resume_token;
  	brinfo_area->n	   = (cnc != 0);
  	if (chsc(brinfo_area))
  		return -EIO;
  	return chsc_error_from_response(brinfo_area->response.code);
  }
  EXPORT_SYMBOL_GPL(chsc_pnso_brinfo);