fd(4): replace disksort() with a bufq

classic Classic list List threaded Threaded
1 message Options
Reply | Threaded
Open this post in threaded view
|

fd(4): replace disksort() with a bufq

David Gwynne-5
this replaces the bare use of disksort with a bufq in fd. this means
it will use the new system default of the nscan sorting algorithm,
but that shouldnt be a noticable change.

it works for me, but i would love to hear from someone with a real
floppy drive still...

ok?

Index: fd.c
===================================================================
RCS file: /cvs/src/sys/dev/isa/fd.c,v
retrieving revision 1.94
diff -u -p -r1.94 fd.c
--- fd.c 11 Jun 2013 16:42:15 -0000 1.94
+++ fd.c 31 Oct 2013 03:05:19 -0000
@@ -119,7 +119,8 @@ struct fd_softc {
 
  TAILQ_ENTRY(fd_softc) sc_drivechain;
  int sc_ops; /* I/O ops since last switch */
- struct buf sc_q; /* head of buf chain */
+ struct bufq sc_bufq; /* pending I/O */
+ struct buf *sc_bp; /* the current I/O */
  struct timeout fd_motor_on_to;
  struct timeout fd_motor_off_to;
  struct timeout fdtimeout_to;
@@ -299,6 +300,7 @@ fdattach(struct device *parent, struct d
  */
  fd->sc_dk.dk_flags = DKF_NOLABELREAD;
  fd->sc_dk.dk_name = fd->sc_dev.dv_xname;
+ bufq_init(&fd->sc_bufq, BUFQ_DEFAULT);
  disk_attach(&fd->sc_dev, &fd->sc_dk);
 
  /* Setup timeout structures */
@@ -414,11 +416,13 @@ fdstrategy(struct buf *bp)
     bp->b_blkno, bp->b_bcount, fd->sc_blkno, bp->b_cylinder, sz);
 #endif
 
+ /* Queue I/O */
+ bufq_queue(&fd->sc_bufq, bp);
+
  /* Queue transfer on drive, activate drive and controller if idle. */
  s = splbio();
- disksort(&fd->sc_q, bp);
  timeout_del(&fd->fd_motor_off_to); /* a good idea */
- if (!fd->sc_q.b_active)
+ if (fd->sc_bp == NULL)
  fdstart(fd);
 #ifdef DIAGNOSTIC
  else {
@@ -449,7 +453,7 @@ fdstart(struct fd_softc *fd)
  int active = !TAILQ_EMPTY(&fdc->sc_link.fdlink.sc_drives);
 
  /* Link into controller queue. */
- fd->sc_q.b_active = 1;
+ fd->sc_bp = bufq_dequeue(&fd->sc_bufq);
  TAILQ_INSERT_TAIL(&fdc->sc_link.fdlink.sc_drives, fd, sc_drivechain);
 
  /* If controller not already active, start it. */
@@ -464,6 +468,10 @@ fdfinish(struct fd_softc *fd, struct buf
 
  splassert(IPL_BIO);
 
+ bp->b_resid = fd->sc_bcount;
+ fd->sc_skip = 0;
+ fd->sc_bp = bufq_dequeue(&fd->sc_bufq);
+
  /*
  * Move this drive to the end of the queue to give others a `fair'
  * chance.  We only force a switch if N operations are completed while
@@ -473,15 +481,11 @@ fdfinish(struct fd_softc *fd, struct buf
  if (TAILQ_NEXT(fd, sc_drivechain) != NULL && ++fd->sc_ops >= 8) {
  fd->sc_ops = 0;
  TAILQ_REMOVE(&fdc->sc_link.fdlink.sc_drives, fd, sc_drivechain);
- if (bp->b_actf) {
+ if (fd->sc_bp != NULL) {
  TAILQ_INSERT_TAIL(&fdc->sc_link.fdlink.sc_drives, fd,
   sc_drivechain);
- } else
- fd->sc_q.b_active = 0;
+ }
  }
- bp->b_resid = fd->sc_bcount;
- fd->sc_skip = 0;
- fd->sc_q.b_actf = bp->b_actf;
 
  biodone(bp);
  /* turn off motor 5s from now */
@@ -661,11 +665,10 @@ loop:
  }
  fd_bsize = FD_BSIZE(fd);
 
- bp = fd->sc_q.b_actf;
+ bp = fd->sc_bp;
  if (bp == NULL) {
  fd->sc_ops = 0;
  TAILQ_REMOVE(&fdc->sc_link.fdlink.sc_drives, fd, sc_drivechain);
- fd->sc_q.b_active = 0;
  goto loop;
  }
 
@@ -927,7 +930,7 @@ fdtimeout(void *arg)
 #endif
  fdcstatus(&fd->sc_dev, 0, "timeout");
 
- if (fd->sc_q.b_actf)
+ if (fd->sc_bp != NULL)
  fdc->sc_state++;
  else
  fdc->sc_state = DEVIDLE;
@@ -940,7 +943,7 @@ void
 fdretry(struct fd_softc *fd)
 {
  struct fdc_softc *fdc = (void *)fd->sc_dev.dv_parent;
- struct buf *bp = fd->sc_q.b_actf;
+ struct buf *bp = fd->sc_bp;
 
  if (fd->sc_opts & FDOPT_NORETRY)
     goto fail;