[src/trunk]: src/sys/dev/isa Let us safely detach the ISA bus and devices att...

[dyoung <dyoung%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/4691dd89a145
branches:  trunk
changeset: 746701:4691dd89a145
user:      dyoung <dyoung%NetBSD.org@localhost>
date:      Tue Aug 18 16:52:42 2009 +0000

description:
Let us safely detach the ISA bus and devices attaching to the ISA
bus:

1 Add isadetach() for detaching the ISA bus, and add some helper
  routines that release resources held for ISA DMA.

2 In isachilddetached(), forget references to child devices.

While I am here, change ISA_DMA_DRQ_ISFREE(...) == 0 to the simpler
expression, !ISA_DMA_DRQ_ISFREE(...).

diffstat:

 sys/dev/isa/isa.c       |  36 ++++++++++++++++++++++++++++++++----
 sys/dev/isa/isadma.c    |  48 ++++++++++++++++++++++++++++++++++++++++++++----
 sys/dev/isa/isadmavar.h |   5 ++++-
 3 files changed, 80 insertions(+), 9 deletions(-)

diffs (182 lines):

diff -r 64da8fb6c0db -r 4691dd89a145 sys/dev/isa/isa.c
--- a/sys/dev/isa/isa.c Tue Aug 18 16:49:24 2009 +0000
+++ b/sys/dev/isa/isa.c Tue Aug 18 16:52:42 2009 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: isa.c,v 1.135 2009/04/07 21:48:46 dyoung Exp $ */
+/*     $NetBSD: isa.c,v 1.136 2009/08/18 16:52:42 dyoung Exp $ */
 
 /*-
  * Copyright (c) 1998, 2001, 2008 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: isa.c,v 1.135 2009/04/07 21:48:46 dyoung Exp $");
+__KERNEL_RCSID(0, "$NetBSD: isa.c,v 1.136 2009/08/18 16:52:42 dyoung Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -56,12 +56,13 @@
 
 int    isamatch(device_t, cfdata_t, void *);
 void   isaattach(device_t, device_t, void *);
+int    isadetach(device_t, int);
 int    isarescan(device_t, const char *, const int *);
 void   isachilddetached(device_t, device_t);
 int    isaprint(void *, const char *);
 
 CFATTACH_DECL2_NEW(isa, sizeof(struct isa_softc),
-    isamatch, isaattach, NULL, NULL, isarescan, isachilddetached);
+    isamatch, isaattach, isadetach, NULL, isarescan, isachilddetached);
 
 void   isa_attach_knowndevs(struct isa_softc *);
 void   isa_free_knowndevs(struct isa_softc *);
@@ -138,6 +139,27 @@
 }
 
 int
+isadetach(device_t self, int flags)
+{
+       struct isa_softc *sc = device_private(self);
+       int rc;
+
+       if ((rc = config_detach_children(self, flags)) != 0)
+               return rc;
+
+       pmf_device_deregister(self);
+
+       isa_free_knowndevs(sc);
+
+#if NISADMA > 0
+       isa_dmadestroy(sc->sc_ic);
+#endif
+       isa_detach_hook(self);
+
+       return 0;
+}
+
+int
 isarescan(device_t self, const char *ifattr, const int *locators)
 {
        int locs[ISACF_NLOCS];
@@ -162,7 +184,13 @@
 void
 isachilddetached(device_t self, device_t child)
 {
-       /* nothing to do */
+       struct isa_knowndev *ik;
+       struct isa_softc *sc = device_private(self);
+
+       TAILQ_FOREACH(ik, &sc->sc_knowndevs, ik_list) {
+               if (ik->ik_claimed == child)
+                       ik->ik_claimed = NULL;
+       }
 }
 
 void
diff -r 64da8fb6c0db -r 4691dd89a145 sys/dev/isa/isadma.c
--- a/sys/dev/isa/isadma.c      Tue Aug 18 16:49:24 2009 +0000
+++ b/sys/dev/isa/isadma.c      Tue Aug 18 16:52:42 2009 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: isadma.c,v 1.61 2009/05/12 09:10:15 cegger Exp $       */
+/*     $NetBSD: isadma.c,v 1.62 2009/08/18 16:52:42 dyoung Exp $       */
 
 /*-
  * Copyright (c) 1997, 1998, 2000 The NetBSD Foundation, Inc.
@@ -35,7 +35,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: isadma.c,v 1.61 2009/05/12 09:10:15 cegger Exp $");
+__KERNEL_RCSID(0, "$NetBSD: isadma.c,v 1.62 2009/08/18 16:52:42 dyoung Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -201,6 +201,24 @@
        }
 }
 
+void
+_isa_dmadestroy(struct isa_dma_state *ids)
+{
+       if (!ids->ids_initialized)
+               return;
+
+       _isa_dmacascade_stop(ids, 4);
+
+       /*
+        * Unmap the registers used by the ISA DMA controller.
+        */
+       bus_space_unmap(ids->ids_bst, ids->ids_dmapgh, 0xf);
+       bus_space_unmap(ids->ids_bst, ids->ids_dma2h, DMA2_IOSIZE);
+       bus_space_unmap(ids->ids_bst, ids->ids_dma1h, DMA1_IOSIZE);
+
+       ids->ids_initialized = 0;
+}
+
 /*
  * _isa_dmacascade(): program 8237 DMA controller channel to accept
  * external dma control by a board.
@@ -215,7 +233,7 @@
                return (EINVAL);
        }
 
-       if (ISA_DMA_DRQ_ISFREE(ids, chan) == 0) {
+       if (!ISA_DMA_DRQ_ISFREE(ids, chan)) {
                printf("%s: DRQ %d is not free\n", device_xname(ids->ids_dev),
                    chan);
                return (EAGAIN);
@@ -235,10 +253,32 @@
        return (0);
 }
 
+/*
+ * _isa_dmacascade_stop(): turn off cascading on the 8237 DMA controller channel
+ * external dma control by a board.
+ */
+int
+_isa_dmacascade_stop(struct isa_dma_state *ids, int chan)
+{
+       if (chan < 0 || chan > 7) {
+               printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
+               return EINVAL;
+       }
+
+       if (ISA_DMA_DRQ_ISFREE(ids, chan))
+               return 0;
+
+       _isa_dmamask(ids, chan);
+
+       ISA_DMA_DRQ_FREE(ids, chan);
+
+       return 0;
+}
+
 int
 _isa_drq_alloc(struct isa_dma_state *ids, int chan)
 {
-       if (ISA_DMA_DRQ_ISFREE(ids, chan) == 0)
+       if (!ISA_DMA_DRQ_ISFREE(ids, chan))
                return EBUSY;
        ISA_DMA_DRQ_ALLOC(ids, chan);
        return 0;
diff -r 64da8fb6c0db -r 4691dd89a145 sys/dev/isa/isadmavar.h
--- a/sys/dev/isa/isadmavar.h   Tue Aug 18 16:49:24 2009 +0000
+++ b/sys/dev/isa/isadmavar.h   Tue Aug 18 16:52:42 2009 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: isadmavar.h,v 1.24 2009/05/12 09:10:15 cegger Exp $    */
+/*     $NetBSD: isadmavar.h,v 1.25 2009/08/18 16:52:42 dyoung Exp $    */
 
 /*-
  * Copyright (c) 1997, 1998, 2000 The NetBSD Foundation, Inc.
@@ -97,7 +97,10 @@
 void      _isa_dmainit(struct isa_dma_state *, bus_space_tag_t,
               bus_dma_tag_t, device_t);
 
+void      _isa_dmadestroy(struct isa_dma_state *);
+
 int       _isa_dmacascade(struct isa_dma_state *, int);
+int       _isa_dmacascade_stop(struct isa_dma_state *, int);
 
 bus_size_t _isa_dmamaxsize(struct isa_dma_state *, int);