dirty fix to merging

1 files changed, 1050 insertions, 0 deletions

diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c
new file mode 100644
index 00000000..a84631a7
--- /dev/null
+++ b/drivers/s390/cio/chsc.c
@@ -0,0 +1,1050 @@
+/*
+ *  drivers/s390/cio/chsc.c
+ *   S/390 common I/O routines -- channel subsystem call
+ *
+ *    Copyright IBM Corp. 1999,2010
+ *    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 <asm/cio.h>
+#include <asm/chpid.h>
+#include <asm/chsc.h>
+#include <asm/crw.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;
+	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)\n",
+			      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;
+}
+
+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_new_sch(struct subchannel_id schid, void *data)
+{
+	struct schib schib;
+	/*
+	 * We don't know the device yet, but since a path
+	 * may be available now to the device we'll have
+	 * to do recognition again.
+	 * Since we don't have any idea about which chpid
+	 * that beast may be on we'll have to do a stsch
+	 * on all devices, grr...
+	 */
+	if (stsch_err(schid, &schib))
+		/* We're through */
+		return -ENXIO;
+
+	/* Put it on the slow path. */
+	css_schedule_eval(schid);
+	return 0;
+}
+
+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,
+				   s390_process_res_acc_new_sch, link);
+}
+
+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_area {
+	struct chsc_header request;
+	u32 reserved1;
+	u32 reserved2;
+	u32 reserved3;
+	struct chsc_header response;
+	u32 reserved4;
+	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 reserved5;
+	u32 reserved6;
+	u8 ccdf[4096 - 16 - 24];	/* content-code dependent field */
+	/* ccdf has to be big enough for a link-incident record */
+} __attribute__ ((packed));
+
+static void chsc_process_sei_link_incident(struct chsc_sei_area *sei_area)
+{
+	struct chp_id chpid;
+	int id;
+
+	CIO_CRW_EVENT(4, "chsc: link incident (rs=%02x, rs_id=%04x)\n",
+		      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\n");
+	else {
+		chp_id_init(&chpid);
+		chpid.id = id;
+		chsc_chp_offline(chpid);
+	}
+}
+
+static void chsc_process_sei_res_acc(struct chsc_sei_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)\n", 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_area *sei_area)
+{
+	struct channel_path *chp;
+	struct chp_id chpid;
+	u8 *data;
+	int num;
+
+	CIO_CRW_EVENT(4, "chsc: channel path availability information\n");
+	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\n", chpid.cssid, chpid.id);
+		chp = chpid_to_chp(chpid);
+		if (!chp) {
+			chp_new(chpid);
+			continue;
+		}
+		mutex_lock(&chp->lock);
+		chsc_determine_base_channel_path_desc(chpid, &chp->desc);
+		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_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\n");
+	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\n",
+			  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(struct chsc_sei_area *sei_area)
+{
+	/* Check if we might have lost some information. */
+	if (sei_area->flags & 0x40) {
+		CIO_CRW_EVENT(2, "chsc: event overflow\n");
+		css_schedule_eval_all();
+	}
+	/* 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;
+	default: /* other stuff */
+		CIO_CRW_EVENT(4, "chsc: unhandled sei content code %d\n",
+			      sei_area->cc);
+		break;
+	}
+}
+
+static void chsc_process_crw(struct crw *crw0, struct crw *crw1, int overflow)
+{
+	struct chsc_sei_area *sei_area;
+
+	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\n",
+		      crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
+		      crw0->erc, crw0->rsid);
+	if (!sei_page)
+		return;
+	/* Access to sei_page is serialized through machine check handler
+	 * thread, so no need for locking. */
+	sei_area = sei_page;
+
+	CIO_TRACE_EVENT(2, "prcss");
+	do {
+		memset(sei_area, 0, sizeof(*sei_area));
+		sei_area->request.length = 0x0010;
+		sei_area->request.code = 0x000e;
+		if (chsc(sei_area))
+			break;
+
+		if (sei_area->response.code == 0x0001) {
+			CIO_CRW_EVENT(4, "chsc: sei successful\n");
+			chsc_process_sei(sei_area);
+		} else {
+			CIO_CRW_EVENT(2, "chsc: sei failed (rc=%04x)\n",
+				      sei_area->response.code);
+			break;
+		}
+	} while (sei_area->flags & 0x80);
+}
+
+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);
+	}
+}
+
+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;
+}
+
+static int
+__s390_vary_chpid_on(struct subchannel_id schid, void *data)
+{
+	struct schib schib;
+
+	if (stsch_err(schid, &schib))
+		/* We're through */
+		return -ENXIO;
+	/* Put it on the slow path. */
+	css_schedule_eval(schid);
+	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 descritor. */
+		chsc_determine_base_channel_path_desc(chpid, &chp->desc);
+		for_each_subchannel_staged(s390_subchannel_vary_chpid_on,
+					   __s390_vary_chpid_on, &chpid);
+	} 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)\n",
+			      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)\n",
+			      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;
+	int ret;
+
+	spin_lock_irq(&chsc_page_lock);
+	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_irq(&chsc_page_lock);
+	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)\n",
+			      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)\n",
+			      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)\n",
+			      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)\n",
+			      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)\n",
+			      schid.ssid, schid.sch_no,
+			      siosl_area->response.code);
+	else
+		CIO_MSG_EVENT(4, "chsc: siosl succeeded for 0.%x.%04x\n",
+			      schid.ssid, schid.sch_no);
+out:
+	spin_unlock_irqrestore(&chsc_page_lock, flags);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(chsc_siosl);