X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=drivers%2Fs390%2Fcio%2Fchsc.c;h=6f05a44e38170c9df7d662298256a986d3873fd0;hb=67c2b7d9d224232ee730b9c9444abed824b62e7a;hp=3bb4e472d73de1f03d111467d9efdd9665067718;hpb=3eeab61aa3ddd3c0bedb7449ada1599de22fdb5a;p=linux-2.6

diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c
index 3bb4e472d7..6f05a44e38 100644
--- a/drivers/s390/cio/chsc.c
+++ b/drivers/s390/cio/chsc.c
@@ -93,7 +93,7 @@ chsc_get_sch_desc_irq(struct subchannel *sch, void *page)
 		u16 sch;	  /* subchannel */
 		u8 chpid[8];	  /* chpids 0-7 */
 		u16 fla[8];	  /* full link addresses 0-7 */
-	} *ssd_area;
+	} __attribute__ ((packed)) *ssd_area;
 
 	ssd_area = page;
 
@@ -183,7 +183,7 @@ css_get_ssd_info(struct subchannel *sch)
 	page = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
 	if (!page)
 		return -ENOMEM;
-	spin_lock_irq(&sch->lock);
+	spin_lock_irq(sch->lock);
 	ret = chsc_get_sch_desc_irq(sch, page);
 	if (ret) {
 		static int cio_chsc_err_msg;
@@ -197,14 +197,16 @@ css_get_ssd_info(struct subchannel *sch)
 			cio_chsc_err_msg = 1;
 		}
 	}
-	spin_unlock_irq(&sch->lock);
+	spin_unlock_irq(sch->lock);
 	free_page((unsigned long)page);
 	if (!ret) {
-		int j, chpid;
+		int j, chpid, mask;
 		/* Allocate channel path structures, if needed. */
 		for (j = 0; j < 8; j++) {
+			mask = 0x80 >> j;
 			chpid = sch->ssd_info.chpid[j];
-			if (chpid && (get_chp_status(chpid) < 0))
+			if ((sch->schib.pmcw.pim & mask) &&
+			    (get_chp_status(chpid) < 0))
 			    new_channel_path(chpid);
 		}
 	}
@@ -222,14 +224,16 @@ s390_subchannel_remove_chpid(struct device *dev, void *data)
 
 	sch = to_subchannel(dev);
 	chpid = data;
-	for (j = 0; j < 8; j++)
-		if (sch->schib.pmcw.chpid[j] == chpid->id)
+	for (j = 0; j < 8; j++) {
+		mask = 0x80 >> j;
+		if ((sch->schib.pmcw.pim & mask) &&
+		    (sch->schib.pmcw.chpid[j] == chpid->id))
 			break;
+	}
 	if (j >= 8)
 		return 0;
 
-	mask = 0x80 >> j;
-	spin_lock_irq(&sch->lock);
+	spin_lock_irq(sch->lock);
 
 	stsch(sch->schid, &schib);
 	if (!schib.pmcw.dnv)
@@ -247,6 +251,8 @@ s390_subchannel_remove_chpid(struct device *dev, void *data)
 		cc = cio_clear(sch);
 		if (cc == -ENODEV)
 			goto out_unreg;
+		/* Request retry of internal operation. */
+		device_set_intretry(sch);
 		/* Call handler. */
 		if (sch->driver && sch->driver->termination)
 			sch->driver->termination(&sch->dev);
@@ -259,10 +265,10 @@ s390_subchannel_remove_chpid(struct device *dev, void *data)
 	else if (sch->lpm == mask)
 		goto out_unreg;
 out_unlock:
-	spin_unlock_irq(&sch->lock);
+	spin_unlock_irq(sch->lock);
 	return 0;
 out_unreg:
-	spin_unlock_irq(&sch->lock);
+	spin_unlock_irq(sch->lock);
 	sch->lpm = 0;
 	if (css_enqueue_subchannel_slow(sch->schid)) {
 		css_clear_subchannel_slow_list();
@@ -271,7 +277,7 @@ out_unreg:
 	return 0;
 }
 
-static inline void
+static void
 s390_set_chpid_offline( __u8 chpid)
 {
 	char dbf_txt[15];
@@ -332,7 +338,7 @@ s390_process_res_acc_sch(struct res_acc_data *res_data, struct subchannel *sch)
 	return 0x80 >> chp;
 }
 
-static inline int
+static int
 s390_process_res_acc_new_sch(struct subchannel_id schid)
 {
 	struct schib schib;
@@ -366,18 +372,18 @@ __s390_process_res_acc(struct subchannel_id schid, void *data)
 	struct res_acc_data *res_data;
 	struct subchannel *sch;
 
-	res_data = (struct res_acc_data *)data;
+	res_data = data;
 	sch = get_subchannel_by_schid(schid);
 	if (!sch)
 		/* Check if a subchannel is newly available. */
 		return s390_process_res_acc_new_sch(schid);
 
-	spin_lock_irq(&sch->lock);
+	spin_lock_irq(sch->lock);
 
 	chp_mask = s390_process_res_acc_sch(res_data, sch);
 
 	if (chp_mask == 0) {
-		spin_unlock_irq(&sch->lock);
+		spin_unlock_irq(sch->lock);
 		put_device(&sch->dev);
 		return 0;
 	}
@@ -391,7 +397,7 @@ __s390_process_res_acc(struct subchannel_id schid, void *data)
 	else if (sch->driver && sch->driver->verify)
 		sch->driver->verify(&sch->dev);
 
-	spin_unlock_irq(&sch->lock);
+	spin_unlock_irq(sch->lock);
 	put_device(&sch->dev);
 	return 0;
 }
@@ -438,9 +444,9 @@ __get_chpid_from_lir(void *data)
 		u32 andesc[28];
 		/* incident-specific information */
 		u32 isinfo[28];
-	} *lir;
+	} __attribute__ ((packed)) *lir;
 
-	lir = (struct lir*) data;
+	lir = data;
 	if (!(lir->iq&0x80))
 		/* NULL link incident record */
 		return -EINVAL;
@@ -455,154 +461,146 @@ __get_chpid_from_lir(void *data)
 	return (u16) (lir->indesc[0]&0x000000ff);
 }
 
-int
-chsc_process_crw(void)
+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 int chsc_process_sei_link_incident(struct chsc_sei_area *sei_area)
+{
+	int chpid;
+
+	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 0;
+	chpid = __get_chpid_from_lir(sei_area->ccdf);
+	if (chpid < 0)
+		CIO_CRW_EVENT(4, "chsc: link incident - invalid LIR\n");
+	else
+		s390_set_chpid_offline(chpid);
+
+	return 0;
+}
+
+static int chsc_process_sei_res_acc(struct chsc_sei_area *sei_area)
 {
-	int chpid, ret;
 	struct res_acc_data res_data;
-	struct {
-		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;
-		u32 ccdf[96];	/* content-code dependent field */
-		/* ccdf has to be big enough for a link-incident record */
-	} *sei_area;
+	struct device *dev;
+	int status;
+	int rc;
+
+	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 0;
+	/* 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)
+		return 0;
+	dev = get_device(&css[0]->chps[sei_area->rsid]->dev);
+	memset(&res_data, 0, sizeof(struct res_acc_data));
+	res_data.chp = to_channelpath(dev);
+	if ((sei_area->vf & 0xc0) != 0) {
+		res_data.fla = sei_area->fla;
+		if ((sei_area->vf & 0xc0) == 0xc0)
+			/* full link address */
+			res_data.fla_mask = 0xffff;
+		else
+			/* link address */
+			res_data.fla_mask = 0xff00;
+	}
+	rc = s390_process_res_acc(&res_data);
+	put_device(dev);
+
+	return rc;
+}
+
+static int chsc_process_sei(struct chsc_sei_area *sei_area)
+{
+	int rc;
+
+	/* Check if we might have lost some information. */
+	if (sei_area->flags & 0x40)
+		CIO_CRW_EVENT(2, "chsc: event overflow\n");
+	/* which kind of information was stored? */
+	rc = 0;
+	switch (sei_area->cc) {
+	case 1: /* link incident*/
+		rc = chsc_process_sei_link_incident(sei_area);
+		break;
+	case 2: /* i/o resource accessibiliy */
+		rc = chsc_process_sei_res_acc(sei_area);
+		break;
+	default: /* other stuff */
+		CIO_CRW_EVENT(4, "chsc: unhandled sei content code %d\n",
+			      sei_area->cc);
+		break;
+	}
+
+	return rc;
+}
+
+int chsc_process_crw(void)
+{
+	struct chsc_sei_area *sei_area;
+	int ret;
+	int rc;
 
 	if (!sei_page)
 		return 0;
-	/*
-	 * build the chsc request block for store event information
-	 * and do the call
-	 * This function is only called by the machine check handler thread,
-	 * so we don't need locking for the sei_page.
-	 */
+	/* 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");
 	ret = 0;
 	do {
-		int ccode, status;
-		struct device *dev;
 		memset(sei_area, 0, sizeof(*sei_area));
-		memset(&res_data, 0, sizeof(struct res_acc_data));
 		sei_area->request.length = 0x0010;
 		sei_area->request.code = 0x000e;
+		if (chsc(sei_area))
+			break;
 
-		ccode = chsc(sei_area);
-		if (ccode > 0)
-			return 0;
-
-		switch (sei_area->response.code) {
-			/* for debug purposes, check for problems */
-		case 0x0001:
-			CIO_CRW_EVENT(4, "chsc_process_crw: event information "
-					"successfully stored\n");
-			break; /* everything ok */
-		case 0x0002:
-			CIO_CRW_EVENT(2,
-				      "chsc_process_crw: invalid command!\n");
-			return 0;
-		case 0x0003:
-			CIO_CRW_EVENT(2, "chsc_process_crw: error in chsc "
-				      "request block!\n");
-			return 0;
-		case 0x0005:
-			CIO_CRW_EVENT(2, "chsc_process_crw: no event "
-				      "information stored\n");
-			return 0;
-		default:
-			CIO_CRW_EVENT(2, "chsc_process_crw: chsc response %d\n",
+		if (sei_area->response.code == 0x0001) {
+			CIO_CRW_EVENT(4, "chsc: sei successful\n");
+			rc = chsc_process_sei(sei_area);
+			if (rc)
+				ret = rc;
+		} else {
+			CIO_CRW_EVENT(2, "chsc: sei failed (rc=%04x)\n",
 				      sei_area->response.code);
-			return 0;
-		}
-
-		/* 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);
+			ret = 0;
 			break;
 		}
 	} while (sei_area->flags & 0x80);
+
 	return ret;
 }
 
-static inline int
+static int
 __chp_add_new_sch(struct subchannel_id schid)
 {
 	struct schib schib;
 	int ret;
 
-	if (stsch(schid, &schib))
+	if (stsch_err(schid, &schib))
 		/* We're through */
 		return need_rescan ? -EAGAIN : -ENXIO;
 
@@ -620,38 +618,41 @@ __chp_add_new_sch(struct subchannel_id schid)
 static int
 __chp_add(struct subchannel_id schid, void *data)
 {
-	int i;
+	int i, mask;
 	struct channel_path *chp;
 	struct subchannel *sch;
 
-	chp = (struct channel_path *)data;
+	chp = 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) {
+	spin_lock_irq(sch->lock);
+	for (i=0; i<8; i++) {
+		mask = 0x80 >> i;
+		if ((sch->schib.pmcw.pim & mask) &&
+		    (sch->schib.pmcw.chpid[i] == chp->id)) {
 			if (stsch(sch->schid, &sch->schib) != 0) {
 				/* Endgame. */
-				spin_unlock_irq(&sch->lock);
+				spin_unlock_irq(sch->lock);
 				return -ENXIO;
 			}
 			break;
 		}
+	}
 	if (i==8) {
-		spin_unlock_irq(&sch->lock);
+		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;
+		    | mask) & sch->opm;
 
 	if (sch->driver && sch->driver->verify)
 		sch->driver->verify(&sch->dev);
 
-	spin_unlock_irq(&sch->lock);
+	spin_unlock_irq(sch->lock);
 	put_device(&sch->dev);
 	return 0;
 }
@@ -700,25 +701,39 @@ chp_process_crw(int chpid, int on)
 	return chp_add(chpid);
 }
 
-static inline int
-__check_for_io_and_kill(struct subchannel *sch, int index)
+static int check_for_io_on_path(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);
+	if (sch->schib.scsw.actl && sch->schib.pmcw.lpum == (0x80 >> index))
 		return 1;
-	}
 	return 0;
 }
 
-static inline void
+static void terminate_internal_io(struct subchannel *sch)
+{
+	if (cio_clear(sch)) {
+		/* Recheck device in case clear failed. */
+		sch->lpm = 0;
+		if (device_trigger_verify(sch) != 0) {
+			if(css_enqueue_subchannel_slow(sch->schid)) {
+				css_clear_subchannel_slow_list();
+				need_rescan = 1;
+			}
+		}
+		return;
+	}
+	/* Request retry of internal operation. */
+	device_set_intretry(sch);
+	/* Call handler. */
+	if (sch->driver && sch->driver->termination)
+		sch->driver->termination(&sch->dev);
+}
+
+static void
 __s390_subchannel_vary_chpid(struct subchannel *sch, __u8 chpid, int on)
 {
 	int chp, old_lpm;
@@ -727,7 +742,7 @@ __s390_subchannel_vary_chpid(struct subchannel *sch, __u8 chpid, int on)
 	if (!sch->ssd_info.valid)
 		return;
 	
-	spin_lock_irqsave(&sch->lock, flags);
+	spin_lock_irqsave(sch->lock, flags);
 	old_lpm = sch->lpm;
 	for (chp = 0; chp < 8; chp++) {
 		if (sch->ssd_info.chpid[chp] != chpid)
@@ -740,25 +755,29 @@ __s390_subchannel_vary_chpid(struct subchannel *sch, __u8 chpid, int on)
 				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) {
+			break;
+		}
+		sch->opm &= ~(0x80 >> chp);
+		sch->lpm &= ~(0x80 >> chp);
+		if (check_for_io_on_path(sch, chp)) {
+			if (device_is_online(sch))
+				/* Path verification is done after killing. */
+				device_kill_io(sch);
+			else
+				/* Kill and retry internal I/O. */
+				terminate_internal_io(sch);
+		} else if (!sch->lpm) {
+			if (device_trigger_verify(sch) != 0) {
 				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);
-		}
+			}
+		} else if (sch->driver && sch->driver->verify)
+			sch->driver->verify(&sch->dev);
 		break;
 	}
-	spin_unlock_irqrestore(&sch->lock, flags);
+	spin_unlock_irqrestore(sch->lock, flags);
 }
 
 static int
@@ -940,8 +959,8 @@ static struct bin_attribute chp_measurement_attr = {
 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);
+	device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
+	device_remove_bin_file(&chp->dev, &chp_measurement_attr);
 }
 
 static int
@@ -949,14 +968,12 @@ chsc_add_chp_cmg_attr(struct channel_path *chp)
 {
 	int ret;
 
-	ret = sysfs_create_bin_file(&chp->dev.kobj,
-				    &chp_measurement_chars_attr);
+	ret = device_create_bin_file(&chp->dev, &chp_measurement_chars_attr);
 	if (ret)
 		return ret;
-	ret = sysfs_create_bin_file(&chp->dev.kobj, &chp_measurement_attr);
+	ret = device_create_bin_file(&chp->dev, &chp_measurement_attr);
 	if (ret)
-		sysfs_remove_bin_file(&chp->dev.kobj,
-				      &chp_measurement_chars_attr);
+		device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
 	return ret;
 }
 
@@ -1015,7 +1032,7 @@ __chsc_do_secm(struct channel_subsystem *css, int enable, void *page)
 		u32 : 4;
 		u32 fmt : 4;
 		u32 : 16;
-	} *secm_area;
+	} __attribute__ ((packed)) *secm_area;
 	int ret, ccode;
 
 	secm_area = page;
@@ -1226,7 +1243,7 @@ chsc_determine_channel_path_description(int chpid,
 		struct chsc_header response;
 		u32 zeroes2;
 		struct channel_path_desc desc;
-	} *scpd_area;
+	} __attribute__ ((packed)) *scpd_area;
 
 	scpd_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
 	if (!scpd_area)
@@ -1323,7 +1340,7 @@ chsc_get_channel_measurement_chars(struct channel_path *chp)
 		u32 cmg : 8;
 		u32 zeroes3;
 		u32 data[NR_MEASUREMENT_CHARS];
-	} *scmc_area;
+	} __attribute__ ((packed)) *scmc_area;
 
 	scmc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
 	if (!scmc_area)
@@ -1463,41 +1480,6 @@ chsc_get_chp_desc(struct subchannel *sch, int chp_no)
 	return desc;
 }
 
-static int reset_channel_path(struct channel_path *chp)
-{
-	int cc;
-
-	cc = rchp(chp->id);
-	switch (cc) {
-	case 0:
-		return 0;
-	case 2:
-		return -EBUSY;
-	default:
-		return -ENODEV;
-	}
-}
-
-static void reset_channel_paths_css(struct channel_subsystem *css)
-{
-	int i;
-
-	for (i = 0; i <= __MAX_CHPID; i++) {
-		if (css->chps[i])
-			reset_channel_path(css->chps[i]);
-	}
-}
-
-void cio_reset_channel_paths(void)
-{
-	int i;
-
-	for (i = 0; i <= __MAX_CSSID; i++) {
-		if (css[i] && css[i]->valid)
-			reset_channel_paths_css(css[i]);
-	}
-}
-
 static int __init
 chsc_alloc_sei_area(void)
 {
@@ -1525,7 +1507,7 @@ chsc_enable_facility(int operation_code)
 		u32 reserved5:4;
 		u32 format2:4;
 		u32 reserved6:24;
-	} *sda_area;
+	} __attribute__ ((packed)) *sda_area;
 
 	sda_area = (void *)get_zeroed_page(GFP_KERNEL|GFP_DMA);
 	if (!sda_area)
@@ -1577,7 +1559,7 @@ chsc_determine_css_characteristics(void)
 		u32 reserved4;
 		u32 general_char[510];
 		u32 chsc_char[518];
-	} *scsc_area;
+	} __attribute__ ((packed)) *scsc_area;
 
 	scsc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
 	if (!scsc_area) {