sys/src/syscancel.c

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// _Id: syscancel.c,v 1.7 2009-05-10 21:24:29 roart Exp $
// _Locker:  $

// Author. Roar Thronæs.
/**
   \file syscancel.c
   \brief QIO cancel
   \author Roar Thronæs
*/

#include<linux/config.h>

#include<starlet.h>
#include<ddtdef.h>
#include<iodef.h>
#include<ipldef.h>
#include<ssdef.h>
#include<misc.h>
#include<irpdef.h>
#include<ucbdef.h>
#include<ccbdef.h>
#include<system_data_cells.h>
#include <queue.h>
#include <ipl.h>
#include<linux/linkage.h>
#include<linux/sched.h>
#include <exe_routines.h>

/**
   \brief cancel i/o on channel
   \param chan i/o channel
*/

asmlinkage int exe_cancel(unsigned short int chan) {
  /** verifies channel legality - MISSING */
  /** handle affinity - MISSING */
  /** set ipl */
  setipl(IPL__ASTDEL);
  struct _ucb * ucb;
  struct _ccb * ccb;
  /** pagefault ccb into memory */
  ccb = &ctl_ga_ccb_table[chan];
  /** higher set ipl - MISSING */
  /** forklock - MISSING */
  ucb = ccb->ccb_l_ucb;
  struct _pcb * pcb = ctl_gl_pcb;
  struct _irp * irph;
  irph = &ucb->ucb_l_ioqfl;
  struct _irp * irp;
  irp = irph->irp_l_ioqfl;
  /** scan irps */
  while (irp!=irph) {
    struct _irp * next = irp->irp_l_ioqfl;
    /** if pids and channels match */
    /** and if virtual clear - MISSING */
    if (irp->irp_l_pid==pcb->pcb$l_pid && irp->irp$w_chan==chan) {
      /** remove irp from queue */
      remque(irp, 0);
      /** clear buffer read bit - MISSING */
      irp->irp_l_iost1 = SS$_CANCEL;
      /** SS__CANCEL status */
      /** check. beware movbuf */
      /** insert at postprocessing queue */
      com_post(irp, ucb);
      /** iopost softint - MISSING */
    }
    irp = next;
  }
  /** invoke driver cancel routine */
  if ((irp = ucb->ucb_l_irp)) {
    // check this later
    //    ucb->ucb_l_irp = 0;
    struct _ddt *ddt; 
    void (*f)(void *,void *, void* ,void *);
    ddt=ucb->ucb_l_ddt;
    f=ddt->ddt_l_cancel;
    f(irp,pcb,ucb,ccb);
  // cancel is according to the book going to get the code from _canceln, but how?
  }
  /** unlock forklock - MISSING */
  /** relinquish affinity - MISSING */
  /** set ipl 0 */
  setipl(0);
  /** no oustanding i/o ccb ioc 0, wind 0, return - MISSING */
  /** device mounted or foreign mount, return - MISSING */
  /** has process section, return - MISSING */
  /** NOTFCP set, return - MISSING */
  /** if no resources etc to allocate irp, return or sch_rwait - MISSING */
  /** irp with acpcontrol etc - MISSING */
  /** charge buffer quota - MISSING */
  /** release forklock and affinity - MISSING */
  /** invoke qioacppkt - MISSING */
  return SS__NORMAL;
}

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