chsc.c

linux 内核源代码

/*
 *  drivers/s390/cio/chsc.c
 *   S/390 common I/O routines -- channel subsystem call
 *
 *    Copyright (C) 1999-2002 IBM Deutschland Entwicklung GmbH,
 *			      IBM Corporation
 *    Author(s): Ingo Adlung ([e-mail])
 *		 Cornelia Huck ([e-mail])
 *		 Arnd Bergmann ([e-mail])
 */

#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 "css.h"
#include "cio.h"
#include "cio_debug.h"
#include "ioasm.h"
#include "chp.h"
#include "chsc.h"

static void *sei_page;

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)
{
	unsigned long page;
	struct chsc_ssd_area *ssd_area;
	int ccode;
	int ret;
	int i;
	int mask;

	page = get_zeroed_page(GFP_KERNEL | GFP_DMA);
	if (!page)
		return -ENOMEM;
	ssd_area = (struct chsc_ssd_area *) 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_free;
	}
	if (ssd_area->response.code != 0x0001) {
		CIO_MSG_EVENT(2, "chsc: ssd failed for 0.%x.%04x (rc=%04x)\n",
			      schid.ssid, schid.sch_no,
			      ssd_area->response.code);
		ret = -EIO;
		goto out_free;
	}
	if (!ssd_area->sch_valid) {
		ret = -ENODEV;
		goto out_free;
	}
	/* Copy data */
	ret = 0;
	memset(ssd, 0, sizeof(struct chsc_ssd_info));
	if ((ssd_area->st != 0) && (ssd_area->st != 2))
		goto out_free;
	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_free:
	free_page(page);
	return ret;
}

static int check_for_io_on_path(struct subchannel *sch, int mask)
{
	int cc;

	cc = stsch(sch->schid, &sch->schib);
	if (cc)
		return 0;
	if (sch->schib.scsw.actl && sch->schib.pmcw.lpum == mask)
		return 1;
	return 0;
}

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)
			css_schedule_eval(sch->schid);
		return;
	}
	/* Request retry of internal operation. */
	device_set_intretry(sch);
	/* Call handler. */
	if (sch->driver && sch->driver->termination)
		sch->driver->termination(&sch->dev);
}

static int
s390_subchannel_remove_chpid(struct device *dev, void *data)
{
	int j;
	int mask;
	struct subchannel *sch;
	struct chp_id *chpid;
	struct schib schib;

	sch = to_subchannel(dev);
	chpid = data;
	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;

	spin_lock_irq(sch->lock);

	stsch(sch->schid, &schib);
	if (!schib.pmcw.dnv)
		goto out_unreg;
	memcpy(&sch->schib, &schib, sizeof(struct schib));
	/* Check for single path devices. */
	if (sch->schib.pmcw.pim == 0x80)
		goto out_unreg;

	if (check_for_io_on_path(sch, mask)) {
		if (device_is_online(sch))
			device_kill_io(sch);
		else {
			terminate_internal_io(sch);
			/* Re-start path verification. */
			if (sch->driver && sch->driver->verify)
				sch->driver->verify(&sch->dev);
		}
	} else {
		/* trigger path verification. */
		if (sch->driver && sch->driver->verify)
			sch->driver->verify(&sch->dev);
		else if (sch->lpm == mask)
			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];

	sprintf(dbf_txt, "chpr%x.%02x", chpid.cssid, chpid.id);
	CIO_TRACE_EVENT(2, dbf_txt);

	if (chp_get_status(chpid) <= 0)
		return;
	bus_for_each_dev(&css_bus_type, NULL, &chpid,
			 s390_subchannel_remove_chpid);
}

static int
s390_process_res_acc_new_sch(struct subchannel_id schid)
{
	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;
}

struct res_acc_data {
	struct chp_id chpid;
	u32 fla_mask;
	u16 fla;
};

static int get_res_chpid_mask(struct chsc_ssd_info *ssd,
			      struct res_acc_data *data)
{
	int i;
	int mask;

	for (i = 0; i < 8; i++) {
		mask = 0x80 >> i;
		if (!(ssd->path_mask & mask))
			continue;
		if (!chp_id_is_equal(&ssd->chpid[i], &data->chpid))
			continue;
		if ((ssd->fla_valid_mask & mask) &&
		    ((ssd->fla[i] & data->fla_mask) != data->fla))
			continue;
		return mask;
	}
	return 0;
}

static int
__s390_process_res_acc(struct subchannel_id schid, void *data)
{
	int chp_mask, old_lpm;
	struct res_acc_data *res_data;
	struct subchannel *sch;

	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);
	chp_mask = get_res_chpid_mask(&sch->ssd_info, res_data);
	if (chp_mask == 0)
		goto out;
	if (stsch(sch->schid, &sch->schib))
		goto out;
	old_lpm = sch->lpm;
	sch->lpm = ((sch->schib.pmcw.pim &
		     sch->schib.pmcw.pam &
		     sch->schib.pmcw.pom)
		    | chp_mask) & sch->opm;
	if (!old_lpm && sch->lpm)
		device_trigger_reprobe(sch);
	else if (sch->driver && sch->driver->verify)
		sch->driver->verify(&sch->dev);
out:
	spin_unlock_irq(sch->lock);
	put_device(&sch->dev);
	return 0;
}

static void s390_process_res_acc (struct res_acc_data *res_data)
{
	char dbf_txt[15];

	sprintf(dbf_txt, "accpr%x.%02x", res_data->chpid.cssid,
		res_data->chpid.id);
	CIO_TRACE_EVENT( 2, dbf_txt);
	if (res_data->fla != 0) {
		sprintf(dbf_txt, "fla%x", res_data->fla);
		CIO_TRACE_EVENT( 2, dbf_txt);
	}

	/*
	 * 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(__s390_process_res_acc, res_data);
}

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 res_acc_data res_data;
	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(&res_data, 0, sizeof(struct res_acc_data));
	res_data.chpid = chpid;
	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;
	}
	s390_process_res_acc(&res_data);
}

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;

	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;
		printk(KERN_WARNING "cio: processing configure event %d for "
		       "chpid %x.%02x\n", 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 accessibiliy */
		chsc_process_sei_res_acc(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;
	}
}

void chsc_process_crw(void)
{
	struct chsc_sei_area *sei_area;

	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);
}

static int
__chp_add_new_sch(struct subchannel_id schid)
{
	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;
}


static int
__chp_add(struct subchannel_id schid, void *data)
{
	int i, mask;
	struct chp_id *chpid;
	struct subchannel *sch;

	chpid = 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++) {
		mask = 0x80 >> i;
		if ((sch->schib.pmcw.pim & mask) &&
		    (sch->schib.pmcw.chpid[i] == chpid->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)
		    | mask) & sch->opm;

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

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