raw3270.c

linux-2.6.15.6

/*
 *  drivers/s390/char/raw3270.c
 *    IBM/3270 Driver - core functions.
 *
 *  Author(s):
 *    Original 3270 Code for 2.4 written by Richard Hitt (UTS Global)
 *    Rewritten for 2.5 by Martin Schwidefsky <[e-mail]>
 *	-- Copyright (C) 2003 IBM Deutschland Entwicklung GmbH, IBM Corporation
 */

#include <linux/config.h>
#include <linux/bootmem.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/wait.h>

#include <asm/ccwdev.h>
#include <asm/cio.h>
#include <asm/ebcdic.h>

#include "raw3270.h"

#include <linux/major.h>
#include <linux/kdev_t.h>
#include <linux/device.h>

struct class *class3270;

/* The main 3270 data structure. */
struct raw3270 {
	struct list_head list;
	struct ccw_device *cdev;
	int minor;

	short model, rows, cols;
	unsigned long flags;

	struct list_head req_queue;	/* Request queue. */
	struct list_head view_list;	/* List of available views. */
	struct raw3270_view *view;	/* Active view. */

	struct timer_list timer;	/* Device timer. */

	unsigned char *ascebc;		/* ascii -> ebcdic table */
	struct class_device *clttydev;	/* 3270-class tty device ptr */
	struct class_device *cltubdev;	/* 3270-class tub device ptr */
};

/* raw3270->flags */
#define RAW3270_FLAGS_14BITADDR	0	/* 14-bit buffer addresses */
#define RAW3270_FLAGS_BUSY	1	/* Device busy, leave it alone */
#define RAW3270_FLAGS_ATTN	2	/* Device sent an ATTN interrupt */
#define RAW3270_FLAGS_READY	4	/* Device is useable by views */
#define RAW3270_FLAGS_CONSOLE	8	/* Device is the console. */

/* Semaphore to protect global data of raw3270 (devices, views, etc). */
static DECLARE_MUTEX(raw3270_sem);

/* List of 3270 devices. */
static struct list_head raw3270_devices = LIST_HEAD_INIT(raw3270_devices);

/*
 * Flag to indicate if the driver has been registered. Some operations
 * like waiting for the end of i/o need to be done differently as long
 * as the kernel is still starting up (console support).
 */
static int raw3270_registered;

/* Module parameters */
static int tubxcorrect = 0;
module_param(tubxcorrect, bool, 0);

/*
 * Wait queue for device init/delete, view delete.
 */
DECLARE_WAIT_QUEUE_HEAD(raw3270_wait_queue);

/*
 * Encode array for 12 bit 3270 addresses.
 */
unsigned char raw3270_ebcgraf[64] =	{
	0x40, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7,
	0xc8, 0xc9, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
	0x50, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7,
	0xd8, 0xd9, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
	0x60, 0x61, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7,
	0xe8, 0xe9, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
	0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
	0xf8, 0xf9, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f
};

void
raw3270_buffer_address(struct raw3270 *rp, char *cp, unsigned short addr)
{
	if (test_bit(RAW3270_FLAGS_14BITADDR, &rp->flags)) {
		cp[0] = (addr >> 8) & 0x3f;
		cp[1] = addr & 0xff;
	} else {
		cp[0] = raw3270_ebcgraf[(addr >> 6) & 0x3f];
		cp[1] = raw3270_ebcgraf[addr & 0x3f];
	}
}

/*
 * Allocate a new 3270 ccw request
 */
struct raw3270_request *
raw3270_request_alloc(size_t size)
{
	struct raw3270_request *rq;

	/* Allocate request structure */
	rq = kmalloc(sizeof(struct raw3270_request), GFP_KERNEL | GFP_DMA);
	if (!rq)
		return ERR_PTR(-ENOMEM);
	memset(rq, 0, sizeof(struct raw3270_request));

	/* alloc output buffer. */
	if (size > 0) {
		rq->buffer = kmalloc(size, GFP_KERNEL | GFP_DMA);
		if (!rq->buffer) {
			kfree(rq);
			return ERR_PTR(-ENOMEM);
		}
	}
	rq->size = size;
	INIT_LIST_HEAD(&rq->list);

	/*
	 * Setup ccw.
	 */
	rq->ccw.cda = __pa(rq->buffer);
	rq->ccw.flags = CCW_FLAG_SLI;

	return rq;
}

#ifdef CONFIG_TN3270_CONSOLE
/*
 * Allocate a new 3270 ccw request from bootmem. Only works very
 * early in the boot process. Only con3270.c should be using this.
 */
struct raw3270_request *
raw3270_request_alloc_bootmem(size_t size)
{
	struct raw3270_request *rq;

	rq = alloc_bootmem_low(sizeof(struct raw3270));
	if (!rq)
		return ERR_PTR(-ENOMEM);
	memset(rq, 0, sizeof(struct raw3270_request));

	/* alloc output buffer. */
	if (size > 0) {
		rq->buffer = alloc_bootmem_low(size);
		if (!rq->buffer) {
			free_bootmem((unsigned long) rq,
				     sizeof(struct raw3270));
			return ERR_PTR(-ENOMEM);
		}
	}
	rq->size = size;
	INIT_LIST_HEAD(&rq->list);

	/*
	 * Setup ccw.
	 */
	rq->ccw.cda = __pa(rq->buffer);
	rq->ccw.flags = CCW_FLAG_SLI;

	return rq;
}
#endif

/*
 * Free 3270 ccw request
 */
void
raw3270_request_free (struct raw3270_request *rq)
{
	kfree(rq->buffer);
	kfree(rq);
}

/*
 * Reset request to initial state.
 */
void
raw3270_request_reset(struct raw3270_request *rq)
{
	BUG_ON(!list_empty(&rq->list));
	rq->ccw.cmd_code = 0;
	rq->ccw.count = 0;
	rq->ccw.cda = __pa(rq->buffer);
	rq->ccw.flags = CCW_FLAG_SLI;
	rq->rescnt = 0;
	rq->rc = 0;
}

/*
 * Set command code to ccw of a request.
 */
void
raw3270_request_set_cmd(struct raw3270_request *rq, u8 cmd)
{
	rq->ccw.cmd_code = cmd;
}

/*
 * Add data fragment to output buffer.
 */
int
raw3270_request_add_data(struct raw3270_request *rq, void *data, size_t size)
{
	if (size + rq->ccw.count > rq->size)
		return -E2BIG;
	memcpy(rq->buffer + rq->ccw.count, data, size);
	rq->ccw.count += size;
	return 0;
}

/*
 * Set address/length pair to ccw of a request.
 */
void
raw3270_request_set_data(struct raw3270_request *rq, void *data, size_t size)
{
	rq->ccw.cda = __pa(data);
	rq->ccw.count = size;
}

/*
 * Set idal buffer to ccw of a request.
 */
void
raw3270_request_set_idal(struct raw3270_request *rq, struct idal_buffer *ib)
{
	rq->ccw.cda = __pa(ib->data);
	rq->ccw.count = ib->size;
	rq->ccw.flags |= CCW_FLAG_IDA;
}

/*
 * Stop running ccw.
 */
static int
raw3270_halt_io_nolock(struct raw3270 *rp, struct raw3270_request *rq)
{
	int retries;
	int rc;

	if (raw3270_request_final(rq))
		return 0;
	/* Check if interrupt has already been processed */
	for (retries = 0; retries < 5; retries++) {
		if (retries < 2)
			rc = ccw_device_halt(rp->cdev, (long) rq);
		else
			rc = ccw_device_clear(rp->cdev, (long) rq);
		if (rc == 0)
			break;		/* termination successful */
	}
	return rc;
}

static int
raw3270_halt_io(struct raw3270 *rp, struct raw3270_request *rq)
{
	unsigned long flags;
	int rc;

	spin_lock_irqsave(get_ccwdev_lock(rp->cdev), flags);
	rc = raw3270_halt_io_nolock(rp, rq);
	spin_unlock_irqrestore(get_ccwdev_lock(rp->cdev), flags);
	return rc;
}

/*
 * Add the request to the request queue, try to start it if the
 * 3270 device is idle. Return without waiting for end of i/o.
 */
static int
__raw3270_start(struct raw3270 *rp, struct raw3270_view *view,
		struct raw3270_request *rq)
{
	rq->view = view;
	raw3270_get_view(view);
	if (list_empty(&rp->req_queue) &&
	    !test_bit(RAW3270_FLAGS_BUSY, &rp->flags)) {
		/* No other requests are on the queue. Start this one. */
		rq->rc = ccw_device_start(rp->cdev, &rq->ccw,
					       (unsigned long) rq, 0, 0);
		if (rq->rc) {
			raw3270_put_view(view);
			return rq->rc;
		}
	}
	list_add_tail(&rq->list, &rp->req_queue);
	return 0;
}

int
raw3270_start(struct raw3270_view *view, struct raw3270_request *rq)
{
	unsigned long flags;
	struct raw3270 *rp;
	int rc;

	spin_lock_irqsave(get_ccwdev_lock(view->dev->cdev), flags);
	rp = view->dev;
	if (!rp || rp->view != view)
		rc = -EACCES;
	else if (!test_bit(RAW3270_FLAGS_READY, &rp->flags))
		rc = -ENODEV;
	else
		rc =  __raw3270_start(rp, view, rq);
	spin_unlock_irqrestore(get_ccwdev_lock(view->dev->cdev), flags);
	return rc;
}

int
raw3270_start_locked(struct raw3270_view *view, struct raw3270_request *rq)
{
	struct raw3270 *rp;
	int rc;

	rp = view->dev;
	if (!rp || rp->view != view)
		rc = -EACCES;
	else if (!test_bit(RAW3270_FLAGS_READY, &rp->flags))
		rc = -ENODEV;
	else
		rc =  __raw3270_start(rp, view, rq);
	return rc;
}

int
raw3270_start_irq(struct raw3270_view *view, struct raw3270_request *rq)
{
	struct raw3270 *rp;

	rp = view->dev;
	rq->view = view;
	raw3270_get_view(view);
	list_add_tail(&rq->list, &rp->req_queue);
	return 0;
}

/*
 * 3270 interrupt routine, called from the ccw_device layer
 */
static void
raw3270_irq (struct ccw_device *cdev, unsigned long intparm, struct irb *irb)
{
	struct raw3270 *rp;
	struct raw3270_view *view;
	struct raw3270_request *rq;
	int rc;

	rp = (struct raw3270 *) cdev->dev.driver_data;
	if (!rp)
		return;
	rq = (struct raw3270_request *) intparm;
	view = rq ? rq->view : rp->view;

	if (IS_ERR(irb))
		rc = RAW3270_IO_RETRY;
	else if (irb->scsw.fctl & SCSW_FCTL_HALT_FUNC) {
		rq->rc = -EIO;
		rc = RAW3270_IO_DONE;
	} else if (irb->scsw.dstat ==  (DEV_STAT_CHN_END | DEV_STAT_DEV_END |
					DEV_STAT_UNIT_EXCEP)) {
		/* Handle CE-DE-UE and subsequent UDE */
		set_bit(RAW3270_FLAGS_BUSY, &rp->flags);
		rc = RAW3270_IO_BUSY;
	} else if (test_bit(RAW3270_FLAGS_BUSY, &rp->flags)) {
		/* Wait for UDE if busy flag is set. */
		if (irb->scsw.dstat & DEV_STAT_DEV_END) {
			clear_bit(RAW3270_FLAGS_BUSY, &rp->flags);
			/* Got it, now retry. */
			rc = RAW3270_IO_RETRY;
		} else
			rc = RAW3270_IO_BUSY;
	} else if (view)
		rc = view->fn->intv(view, rq, irb);
	else
		rc = RAW3270_IO_DONE;

	switch (rc) {
	case RAW3270_IO_DONE:
		break;
	case RAW3270_IO_BUSY:
		/* 
		 * Intervention required by the operator. We have to wait
		 * for unsolicited device end.
		 */
		return;
	case RAW3270_IO_RETRY:
		if (!rq)
			break;
		rq->rc = ccw_device_start(rp->cdev, &rq->ccw,
					  (unsigned long) rq, 0, 0);
		if (rq->rc == 0)
			return;	/* Sucessfully restarted. */
		break;
	case RAW3270_IO_STOP:
		if (!rq)
			break;
		raw3270_halt_io_nolock(rp, rq);
		rq->rc = -EIO;
		break;
	default:
		BUG();
	}
	if (rq) {
		BUG_ON(list_empty(&rq->list));
		/* The request completed, remove from queue and do callback. */
		list_del_init(&rq->list);
		if (rq->callback)
			rq->callback(rq, rq->callback_data);
		/* Do put_device for get_device in raw3270_start. */
		raw3270_put_view(view);
	}
	/*
	 * Try to start each request on request queue until one is
	 * started successful.
	 */
	while (!list_empty(&rp->req_queue)) {
		rq = list_entry(rp->req_queue.next,struct raw3270_request,list);
		rq->rc = ccw_device_start(rp->cdev, &rq->ccw,
					  (unsigned long) rq, 0, 0);
		if (rq->rc == 0)
			break;
		/* Start failed. Remove request and do callback. */
		list_del_init(&rq->list);
		if (rq->callback)
			rq->callback(rq, rq->callback_data);
		/* Do put_device for get_device in raw3270_start. */
		raw3270_put_view(view);
	}
}

/*
 * Size sensing.
 */

struct raw3270_ua {	/* Query Reply structure for Usable Area */
	struct {	/* Usable Area Query Reply Base */
		short l;	/* Length of this structured field */
		char  sfid;	/* 0x81 if Query Reply */
		char  qcode;	/* 0x81 if Usable Area */
		char  flags0;
		char  flags1;
		short w;	/* Width of usable area */
		short h;	/* Heigth of usavle area */
		char  units;	/* 0x00:in; 0x01:mm */
		int   xr;
		int   yr;
		char  aw;
		char  ah;
		short buffsz;	/* Character buffer size, bytes */
		char  xmin;
		char  ymin;
		char  xmax;
		char  ymax;
	} __attribute__ ((packed)) uab;
	struct {	/* Alternate Usable Area Self-Defining Parameter */
		char  l;	/* Length of this Self-Defining Parm */