re: 5.99.30 sparc panic during startup

[matthew green <mrg%eterna.com.au@localhost>]

> > Somebody should fix the driver so that zshard() does not call
> > device_lookup_private().  It seems entirely unnecessary.
> 
> There is a dumb hack in sun3 derived zs driver.
> 
> All zs devices on sun machines have the same interrupt sources
> so ancient zs drivers tried to reduce overhead on interrupts
> by sharing one interrupt handler among all zs devices.
> 
> We can simpley fix it to make it call softint_establish() and
> bus_intr_establish() per each zs device, as macppc and news68k etc. do.

i don't understand.

the macppc and news68k zshard()'s get the actual zsc_softc * as
the (void *arg), but sparc does not.

seems like the only way to deal with this is to keep a local
copy of the zsc structures some how and to traverse this inside
of zshard().

i probably should have used queue.h but i finished this patch
before i considered it...  my ss20 has booted just fine with
this patch but it wasn't failing before either.


.mrg.


Index: include/z8530var.h
===================================================================
RCS file: /cvsroot/src/sys/arch/sparc/include/z8530var.h,v
retrieving revision 1.9
diff -p -r1.9 z8530var.h
*** include/z8530var.h  29 Mar 2008 19:15:35 -0000      1.9
--- include/z8530var.h  20 Jun 2010 01:34:29 -0000
*************** struct zsc_softc {
*** 54,59 ****
--- 54,65 ----
        int                     zsc_node;       /* PROM node, if any */
        struct evcnt            zsc_intrcnt;    /* count interrupts */
        struct zs_chanstate     zsc_cs_store[2];
+ 
+       /*
+        * This is used for zshard() to avoid having to call
+        * device_lookup_private() from IPL_HIGH.
+        */
+       struct zsc_softc        *zsc_next;
  };
  
  /*
Index: dev/zs.c
===================================================================
RCS file: /cvsroot/src/sys/arch/sparc/dev/zs.c,v
retrieving revision 1.118
diff -p -r1.118 zs.c
*** dev/zs.c    4 Jun 2010 06:04:15 -0000       1.118
--- dev/zs.c    20 Jun 2010 01:34:29 -0000
*************** extern struct cfdriver zs_cd;
*** 174,179 ****
--- 174,182 ----
  /* softintr(9) cookie, shared by all instances of this driver */
  static void *zs_sicookie;
  
+ /* Linked list of zs instances, for fast lookups in zshard */
+ static struct zsc_softc *zsc_first;
+ 
  /* Interrupt handlers. */
  static int zshard(void *);
  static void zssoft(void *);
*************** zs_attach(struct zsc_softc *zsc, struct 
*** 566,571 ****
--- 569,580 ----
        }
  
        /*
+        * Install this zs into the zshard fast lookup list.
+        */
+       zsc->zsc_next = zsc_first;
+       zsc_first = zsc;
+ 
+       /*
         * Now safe to install interrupt handlers.  Note the arguments
         * to the interrupt handlers aren't used.  Note, we only do this
         * once since both SCCs interrupt at the same level and vector.
*************** static int
*** 632,646 ****
  zshard(void *arg)
  {
        struct zsc_softc *zsc;
!       int unit, rr3, rval, softreq;
  
        rval = softreq = 0;
!       for (unit = 0; unit < zs_cd.cd_ndevs; unit++) {
                struct zs_chanstate *cs;
  
-               zsc = device_lookup_private(&zs_cd, unit);
-               if (zsc == NULL)
-                       continue;
                rr3 = zsc_intr_hard(zsc);
                /* Count up the interrupts. */
                if (rr3) {
--- 641,652 ----
  zshard(void *arg)
  {
        struct zsc_softc *zsc;
!       int rr3, rval, softreq;
  
        rval = softreq = 0;
!       for (zsc = zsc_first; zsc; zsc = zsc->zsc_next) {
                struct zs_chanstate *cs;
  
                rr3 = zsc_intr_hard(zsc);
                /* Count up the interrupts. */
                if (rr3) {