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

/*
 * Driver for s390 chsc subchannels
 *
 * Copyright IBM Corp. 2008, 2011
 *
 * Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
 *
 */

#include <linux/slab.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/uaccess.h>
#include <linux/miscdevice.h>
#include <linux/kernel_stat.h>

#include <asm/compat.h>
#include <asm/cio.h>
#include <asm/chsc.h>
#include <asm/isc.h>

#include "cio.h"
#include "cio_debug.h"
#include "css.h"
#include "chsc_sch.h"
#include "ioasm.h"

static debug_info_t *chsc_debug_msg_id;
static debug_info_t *chsc_debug_log_id;

#define CHSC_MSG(imp, args...) do {					\
		debug_sprintf_event(chsc_debug_msg_id, imp , ##args);	\
	} while (0)

#define CHSC_LOG(imp, txt) do {					\
		debug_text_event(chsc_debug_log_id, imp , txt);	\
	} while (0)

static void CHSC_LOG_HEX(int level, void *data, int length)
{
	while (length > 0) {
		debug_event(chsc_debug_log_id, level, data, length);
		length -= chsc_debug_log_id->buf_size;
		data += chsc_debug_log_id->buf_size;
	}
}

MODULE_AUTHOR("IBM Corporation");
MODULE_DESCRIPTION("driver for s390 chsc subchannels");
MODULE_LICENSE("GPL");

static void chsc_subchannel_irq(struct subchannel *sch)
{
	struct chsc_private *private = dev_get_drvdata(&sch->dev);
	struct chsc_request *request = private->request;
	struct irb *irb = (struct irb *)&S390_lowcore.irb;

	CHSC_LOG(4, "irb");
	CHSC_LOG_HEX(4, irb, sizeof(*irb));
	kstat_cpu(smp_processor_id()).irqs[IOINT_CSC]++;

	/* Copy irb to provided request and set done. */
	if (!request) {
		CHSC_MSG(0, "Interrupt on sch 0.%x.%04x with no request\n",
			 sch->schid.ssid, sch->schid.sch_no);
		return;
	}
	private->request = NULL;
	memcpy(&request->irb, irb, sizeof(*irb));
	cio_update_schib(sch);
	complete(&request->completion);
	put_device(&sch->dev);
}

static int chsc_subchannel_probe(struct subchannel *sch)
{
	struct chsc_private *private;
	int ret;

	CHSC_MSG(6, "Detected chsc subchannel 0.%x.%04x\n",
		 sch->schid.ssid, sch->schid.sch_no);
	sch->isc = CHSC_SCH_ISC;
	private = kzalloc(sizeof(*private), GFP_KERNEL);
	if (!private)
		return -ENOMEM;
	dev_set_drvdata(&sch->dev, private);
	ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch);
	if (ret) {
		CHSC_MSG(0, "Failed to enable 0.%x.%04x: %d\n",
			 sch->schid.ssid, sch->schid.sch_no, ret);
		dev_set_drvdata(&sch->dev, NULL);
		kfree(private);
	} else {
		if (dev_get_uevent_suppress(&sch->dev)) {
			dev_set_uevent_suppress(&sch->dev, 0);
			kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
		}
	}
	return ret;
}

static int chsc_subchannel_remove(struct subchannel *sch)
{
	struct chsc_private *private;

	cio_disable_subchannel(sch);
	private = dev_get_drvdata(&sch->dev);
	dev_set_drvdata(&sch->dev, NULL);
	if (private->request) {
		complete(&private->request->completion);
		put_device(&sch->dev);
	}
	kfree(private);
	return 0;
}

static void chsc_subchannel_shutdown(struct subchannel *sch)
{
	cio_disable_subchannel(sch);
}

static int chsc_subchannel_prepare(struct subchannel *sch)
{
	int cc;
	struct schib schib;
	/*
	 * Don't allow suspend while the subchannel is not idle
	 * since we don't have a way to clear the subchannel and
	 * cannot disable it with a request running.
	 */
	cc = stsch_err(sch->schid, &schib);
	if (!cc && scsw_stctl(&schib.scsw))
		return -EAGAIN;
	return 0;
}

static int chsc_subchannel_freeze(struct subchannel *sch)
{
	return cio_disable_subchannel(sch);
}

static int chsc_subchannel_restore(struct subchannel *sch)
{
	return cio_enable_subchannel(sch, (u32)(unsigned long)sch);
}

static struct css_device_id chsc_subchannel_ids[] = {
	{ .match_flags = 0x1, .type =SUBCHANNEL_TYPE_CHSC, },
	{ /* end of list */ },
};
MODULE_DEVICE_TABLE(css, chsc_subchannel_ids);

static struct css_driver chsc_subchannel_driver = {
	.drv = {
		.owner = THIS_MODULE,
		.name = "chsc_subchannel",
	},
	.subchannel_type = chsc_subchannel_ids,
	.irq = chsc_subchannel_irq,
	.probe = chsc_subchannel_probe,
	.remove = chsc_subchannel_remove,
	.shutdown = chsc_subchannel_shutdown,
	.prepare = chsc_subchannel_prepare,
	.freeze = chsc_subchannel_freeze,
	.thaw = chsc_subchannel_restore,
	.restore = chsc_subchannel_restore,
};

static int __init chsc_init_dbfs(void)
{
	chsc_debug_msg_id = debug_register("chsc_msg", 16, 1,