/*
   *  CCW device SENSE ID I/O handling.
   *
   *    Copyright IBM Corp. 2002, 2009
   *    Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
   *		 Martin Schwidefsky <schwidefsky@de.ibm.com>
   *		 Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
   */
  
  #include <linux/kernel.h>
  #include <linux/string.h>
  #include <linux/types.h>
  #include <linux/errno.h>
  #include <asm/ccwdev.h>
  #include <asm/setup.h>
  #include <asm/cio.h>
  #include <asm/diag.h>
  
  #include "cio.h"
  #include "cio_debug.h"
  #include "device.h"
  #include "io_sch.h"
  
  #define SENSE_ID_RETRIES	256
  #define SENSE_ID_TIMEOUT	(10 * HZ)
  #define SENSE_ID_MIN_LEN	4
  #define SENSE_ID_BASIC_LEN	7
  
  /**
   * diag210_to_senseid - convert diag 0x210 data to sense id information
   * @senseid: sense id
   * @diag: diag 0x210 data
   *
   * Return 0 on success, non-zero otherwise.
   */
  static int diag210_to_senseid(struct senseid *senseid, struct diag210 *diag)
  {
  	static struct {
  		int class, type, cu_type;
  	} vm_devices[] = {
  		{ 0x08, 0x01, 0x3480 },
  		{ 0x08, 0x02, 0x3430 },
  		{ 0x08, 0x10, 0x3420 },
  		{ 0x08, 0x42, 0x3424 },
  		{ 0x08, 0x44, 0x9348 },
  		{ 0x08, 0x81, 0x3490 },
  		{ 0x08, 0x82, 0x3422 },
  		{ 0x10, 0x41, 0x1403 },
  		{ 0x10, 0x42, 0x3211 },
  		{ 0x10, 0x43, 0x3203 },
  		{ 0x10, 0x45, 0x3800 },
  		{ 0x10, 0x47, 0x3262 },
  		{ 0x10, 0x48, 0x3820 },
  		{ 0x10, 0x49, 0x3800 },
  		{ 0x10, 0x4a, 0x4245 },
  		{ 0x10, 0x4b, 0x4248 },
  		{ 0x10, 0x4d, 0x3800 },
  		{ 0x10, 0x4e, 0x3820 },
  		{ 0x10, 0x4f, 0x3820 },
  		{ 0x10, 0x82, 0x2540 },
  		{ 0x10, 0x84, 0x3525 },
  		{ 0x20, 0x81, 0x2501 },
  		{ 0x20, 0x82, 0x2540 },
  		{ 0x20, 0x84, 0x3505 },
  		{ 0x40, 0x01, 0x3278 },
  		{ 0x40, 0x04, 0x3277 },
  		{ 0x40, 0x80, 0x2250 },
  		{ 0x40, 0xc0, 0x5080 },
  		{ 0x80, 0x00, 0x3215 },
  	};
  	int i;
  
  	/* Special case for osa devices. */
  	if (diag->vrdcvcla == 0x02 && diag->vrdcvtyp == 0x20) {
  		senseid->cu_type = 0x3088;
  		senseid->cu_model = 0x60;
  		senseid->reserved = 0xff;
  		return 0;
  	}
  	for (i = 0; i < ARRAY_SIZE(vm_devices); i++) {
  		if (diag->vrdcvcla == vm_devices[i].class &&
  		    diag->vrdcvtyp == vm_devices[i].type) {
  			senseid->cu_type = vm_devices[i].cu_type;
  			senseid->reserved = 0xff;
  			return 0;
  		}
  	}
  
  	return -ENODEV;
  }
  
  /**
   * diag_get_dev_info - retrieve device information via diag 0x210
   * @cdev: ccw device
   *
   * Returns zero on success, non-zero otherwise.
   */
  static int diag210_get_dev_info(struct ccw_device *cdev)
  {
  	struct ccw_dev_id *dev_id = &cdev->private->dev_id;
  	struct senseid *senseid = &cdev->private->senseid;
  	struct diag210 diag_data;
  	int rc;
  
  	if (dev_id->ssid != 0)
  		return -ENODEV;
  	memset(&diag_data, 0, sizeof(diag_data));
  	diag_data.vrdcdvno	= dev_id->devno;
  	diag_data.vrdclen	= sizeof(diag_data);
  	rc = diag210(&diag_data);
  	CIO_TRACE_EVENT(4, "diag210");
  	CIO_HEX_EVENT(4, &rc, sizeof(rc));
  	CIO_HEX_EVENT(4, &diag_data, sizeof(diag_data));
  	if (rc != 0 && rc != 2)
  		goto err_failed;
  	if (diag210_to_senseid(senseid, &diag_data))
  		goto err_unknown;
  	return 0;
  
  err_unknown:
  	CIO_MSG_EVENT(0, "snsid: device 0.%x.%04x: unknown diag210 data
  ",
  		      dev_id->ssid, dev_id->devno);
  	return -ENODEV;
  err_failed:
  	CIO_MSG_EVENT(0, "snsid: device 0.%x.%04x: diag210 failed (rc=%d)
  ",
  		      dev_id->ssid, dev_id->devno, rc);
  	return -ENODEV;
  }
  
  /*
   * Initialize SENSE ID data.
   */
  static void snsid_init(struct ccw_device *cdev)
  {
  	cdev->private->flags.esid = 0;
  	memset(&cdev->private->senseid, 0, sizeof(cdev->private->senseid));
  	cdev->private->senseid.cu_type = 0xffff;
  }
  
  /*
   * Check for complete SENSE ID data.
   */
  static int snsid_check(struct ccw_device *cdev, void *data)
  {
  	struct cmd_scsw *scsw = &cdev->private->irb.scsw.cmd;
  	int len = sizeof(struct senseid) - scsw->count;
  
  	/* Check for incomplete SENSE ID data. */
  	if (len < SENSE_ID_MIN_LEN)
  		goto out_restart;
  	if (cdev->private->senseid.cu_type == 0xffff)
  		goto out_restart;
  	/* Check for incompatible SENSE ID data. */
  	if (cdev->private->senseid.reserved != 0xff)
  		return -EOPNOTSUPP;
  	/* Check for extended-identification information. */
  	if (len > SENSE_ID_BASIC_LEN)
  		cdev->private->flags.esid = 1;
  	return 0;
  
  out_restart:
  	snsid_init(cdev);
  	return -EAGAIN;
  }
  
  /*
   * Process SENSE ID request result.
   */
  static void snsid_callback(struct ccw_device *cdev, void *data, int rc)
  {
  	struct ccw_dev_id *id = &cdev->private->dev_id;
  	struct senseid *senseid = &cdev->private->senseid;
  	int vm = 0;
  
  	if (rc && MACHINE_IS_VM) {
  		/* Try diag 0x210 fallback on z/VM. */
  		snsid_init(cdev);
  		if (diag210_get_dev_info(cdev) == 0) {
  			rc = 0;
  			vm = 1;
  		}
  	}
  	CIO_MSG_EVENT(2, "snsid: device 0.%x.%04x: rc=%d %04x/%02x "
  		      "%04x/%02x%s
  ", id->ssid, id->devno, rc,
  		      senseid->cu_type, senseid->cu_model, senseid->dev_type,
  		      senseid->dev_model, vm ? " (diag210)" : "");
  	ccw_device_sense_id_done(cdev, rc);
  }
  
  /**
   * ccw_device_sense_id_start - perform SENSE ID
   * @cdev: ccw device
   *
   * Execute a SENSE ID channel program on @cdev to update its sense id
   * information. When finished, call ccw_device_sense_id_done with a
   * return code specifying the result.
   */
  void ccw_device_sense_id_start(struct ccw_device *cdev)
  {
  	struct subchannel *sch = to_subchannel(cdev->dev.parent);
  	struct ccw_request *req = &cdev->private->req;
  	struct ccw1 *cp = cdev->private->iccws;
  
  	CIO_TRACE_EVENT(4, "snsid");
  	CIO_HEX_EVENT(4, &cdev->private->dev_id, sizeof(cdev->private->dev_id));
  	/* Data setup. */
  	snsid_init(cdev);
  	/* Channel program setup. */
  	cp->cmd_code	= CCW_CMD_SENSE_ID;
  	cp->cda		= (u32) (addr_t) &cdev->private->senseid;
  	cp->count	= sizeof(struct senseid);
  	cp->flags	= CCW_FLAG_SLI;
  	/* Request setup. */
  	memset(req, 0, sizeof(*req));
  	req->cp		= cp;
  	req->timeout	= SENSE_ID_TIMEOUT;
  	req->maxretries	= SENSE_ID_RETRIES;
  	req->lpm	= sch->schib.pmcw.pam & sch->opm;
  	req->check	= snsid_check;
  	req->callback	= snsid_callback;
  	ccw_request_start(cdev);
  }