path: root/drivers/s390/cio/css.c

/*
 *  drivers/s390/cio/css.c
 *  driver for channel subsystem
 *
 *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
 *			 IBM Corporation
 *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
 *		 Cornelia Huck (cornelia.huck@de.ibm.com)
 */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/list.h>
#include <linux/reboot.h>

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

int css_init_done = 0;
static int need_reprobe = 0;
static int max_ssid = 0;

struct channel_subsystem *channel_subsystems[__MAX_CSSID + 1];

int css_characteristics_avail = 0;

int
for_each_subchannel(int(*fn)(struct subchannel_id, void *), void *data)
{
	struct subchannel_id schid;
	int ret;

	init_subchannel_id(&schid);
	ret = -ENODEV;
	do {
		do {
			ret = fn(schid, data);
			if (ret)
				break;
		} while (schid.sch_no++ < __MAX_SUBCHANNEL);
		schid.sch_no = 0;
	} while (schid.ssid++ < max_ssid);
	return ret;
}

static struct subchannel *
css_alloc_subchannel(struct subchannel_id schid)
{
	struct subchannel *sch;
	int ret;

	sch = kmalloc (sizeof (*sch), GFP_KERNEL | GFP_DMA);
	if (sch == NULL)
		return ERR_PTR(-ENOMEM);
	ret = cio_validate_subchannel (sch, schid);
	if (ret < 0) {
		kfree(sch);
		return ERR_PTR(ret);
	}

	if (sch->st != SUBCHANNEL_TYPE_IO) {
		/* For now we ignore all non-io subchannels. */
		kfree(sch);
		return ERR_PTR(-EINVAL);
	}

	/* 
	 * Set intparm to subchannel address.
	 * This is fine even on 64bit since the subchannel is always located
	 * under 2G.
	 */
	sch->schib.pmcw.intparm = (u32)(addr_t)sch;
	ret = cio_modify(sch);
	if (ret) {
		kfree(sch->lock);
		kfree(sch);
		return ERR_PTR(ret);
	}
	return sch;
}

static void
css_free_subchannel(struct subchannel *sch)
{
	if (sch) {
		/* Reset intparm to zeroes. */
		sch->schib.pmcw.intparm = 0;
		cio_modify(sch);
		kfree(sch->lock);
		kfree(sch);
	}
}

static void
css_subchannel_release(struct device *dev)
{
	struct subchannel *sch;

	sch = to_subchannel(dev);
	if (!cio_is_console(sch->schid)) {
		kfree(sch->lock);
		kfree(sch);
	}
}

static int css_sch_device_register(struct subchannel *sch)
{
	int ret;

	mutex_lock(&sch->reg_mutex);
	ret = device_register(&sch->dev);
	mutex_unlock(&sch->reg_mutex);
	return ret;
}

void css_sch_device_unregister(struct subchannel *sch)
{
	mutex_lock(&sch->reg_mutex);
	device_unregister(&sch->dev);
	mutex_unlock(&sch->reg_mutex);
}

static void ssd_from_pmcw(struct chsc_ssd_info *ssd, struct pmcw *pmcw)
{
	int i;
	int mask;

	memset(ssd, 0, sizeof(struct chsc_ssd_info));
	ssd->path_mask = pmcw->pim;
	for (i = 0; i < 8; i++) {
		mask = 0x80 >> i;
		if (pmcw->pim & mask) {
			chp_id_init(&ssd->chpid[i]);
			ssd->chpid[i].id = pmcw->chpid[i];
		}
	}
}

static void ssd_register_chpids(struct chsc_ssd_info *ssd)
{
	int i;
	int mask;

	for (i = 0; i < 8; i++) {
		mask = 0x80 >> i;
		if (ssd->path_mask & mask)
			if (!chp_is_registered(ssd->chpid[i]))
				chp_new(ssd->chpid[i]);
	}
}

void css_update_ssd_info(struct subchannel *sch)
{
	int ret;

	if (cio_is_console(sch->schid)) {
		/* Console is initialized too early for functions requiring
		 * memory allocation. */
		ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
	} else {
		ret = chsc_get_ssd_info(sch->schid, &sch->ssd_info);
		if (ret)
			ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
		ssd_register_chpids(&sch->ssd_info);
	}
}

static int css_register_subchannel(struct subchannel *sch)
{
	int ret;

	/* Initialize the subchannel structure */
	sch->