[src/trunk]: src/sys/dev/ic ensure the device's UVM pager object is present b...

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

details:   https://anonhg.NetBSD.org/src/rev/1e29a65c2104
branches:  trunk
changeset: 840014:1e29a65c2104
user:      tnn <tnn%NetBSD.org@localhost>
date:      Sun Mar 17 04:03:17 2019 +0000

description:
ensure the device's UVM pager object is present before using uvm_pageratop

diffstat:

 sys/dev/ic/ssdfb.c    |  41 ++++++++++++++++++++++++++++++++++++-----
 sys/dev/ic/ssdfbvar.h |   3 ++-
 2 files changed, 38 insertions(+), 6 deletions(-)

diffs (141 lines):

diff -r 86e8c71ea7bd -r 1e29a65c2104 sys/dev/ic/ssdfb.c
--- a/sys/dev/ic/ssdfb.c        Sun Mar 17 01:47:57 2019 +0000
+++ b/sys/dev/ic/ssdfb.c        Sun Mar 17 04:03:17 2019 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: ssdfb.c,v 1.2 2019/03/17 01:33:02 tnn Exp $ */
+/* $NetBSD: ssdfb.c,v 1.3 2019/03/17 04:03:17 tnn Exp $ */
 
 /*
  * Copyright (c) 2019 The NetBSD Foundation, Inc.
@@ -30,13 +30,15 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ssdfb.c,v 1.2 2019/03/17 01:33:02 tnn Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ssdfb.c,v 1.3 2019/03/17 04:03:17 tnn Exp $");
 
 #include "opt_ddb.h"
 
 #include <sys/param.h>
 #include <sys/kernel.h>
+#include <sys/conf.h>
 #include <uvm/uvm_page.h>
+#include <uvm/uvm_device.h>
 #include <sys/condvar.h>
 #include <sys/kmem.h>
 #include <sys/kthread.h>
@@ -75,6 +77,7 @@
 static int     ssdfb_set_mode(struct ssdfb_softc *, u_int);
 
 /* frame buffer damage tracking and synchronization */
+static void    ssdfb_udv_attach(struct ssdfb_softc *sc);
 static bool    ssdfb_is_modified(struct ssdfb_softc *sc);
 static bool    ssdfb_clear_modify(struct ssdfb_softc *sc);
 static void    ssdfb_damage(struct ssdfb_softc *);
@@ -189,7 +192,6 @@
 
 #define SSDFB_CMD1(c) do { cmd[0] = (c); error = sc->sc_cmd(sc->sc_cookie, cmd, 1, usepoll); } while(0)
 #define SSDFB_CMD2(c, a) do { cmd[0] = (c); cmd[1] = (a); error = sc->sc_cmd(sc->sc_cookie, cmd, 2, usepoll); } while(0)
-#define SSDFB_CMD3(c, a, b) do { cmd[0] = (c); cmd[1] = (a); cmd[2] = (b); error = sc->sc_cmd(sc->sc_cookie, cmd, 3, usepoll); } while(0)
 
 void
 ssdfb_attach(struct ssdfb_softc *sc, int flags)
@@ -349,6 +351,11 @@
        mutex_exit(&sc->sc_cond_mtx);
        kthread_join(sc->sc_thread);
 
+       if (sc->sc_uobj != NULL) {
+               mutex_enter(sc->sc_uobj->vmobjlock);
+               sc->sc_uobj->uo_refs--;
+               mutex_exit(sc->sc_uobj->vmobjlock);
+       }
        config_detach(sc->sc_wsdisplay, DETACH_FORCE);
 
        cv_destroy(&sc->sc_cond);
@@ -441,7 +448,7 @@
        case WSDISPLAYIO_GETCMAP:
                wc = (struct wsdisplay_cmap *)data;
                if (wc->index >= __arraycount(cmap) ||
-                   wc->count >= __arraycount(cmap) - wc->index)
+                   wc->count >  __arraycount(cmap) - wc->index)
                        return EINVAL;
                error = copyout(&cmap[wc->index], wc->red, wc->count);
                if (error)
@@ -576,7 +583,7 @@
 ssdfb_init(struct ssdfb_softc *sc)
 {
        int error;
-       uint8_t cmd[3];
+       uint8_t cmd[2];
        bool usepoll = true;
 
        /*
@@ -745,6 +752,18 @@
        }
 }
 
+static void
+ssdfb_udv_attach(struct ssdfb_softc *sc)
+{
+       extern const struct cdevsw wsdisplay_cdevsw;
+       dev_t dev;
+#define WSDISPLAYMINOR(unit, screen)   (((unit) << 8) | (screen))
+       dev = makedev(cdevsw_lookup_major(&wsdisplay_cdevsw),
+           WSDISPLAYMINOR(device_unit(sc->sc_wsdisplay), 0));
+       sc->sc_uobj = udv_attach(dev, VM_PROT_READ|VM_PROT_WRITE, 0,
+           sc->sc_ri_bits_len);
+}
+
 static bool
 ssdfb_is_modified(struct ssdfb_softc *sc)
 {
@@ -753,6 +772,9 @@
        if (sc->sc_mode == WSDISPLAYIO_MODE_EMUL)
                return sc->sc_modified;
 
+       if (sc->sc_uobj == NULL)
+               return false;
+
        va = (vaddr_t)sc->sc_ri.ri_bits;
        va_end = va + sc->sc_ri_bits_len;
        while (va < va_end) {
@@ -776,6 +798,9 @@
                return ret;
        }
 
+       if (sc->sc_uobj == NULL)
+               return false;
+
        va = (vaddr_t)sc->sc_ri.ri_bits;
        va_end = va + sc->sc_ri_bits_len;
        ret = false;
@@ -800,6 +825,12 @@
                ssdfb_set_usepoll(sc, false);
 
        while(!sc->sc_detaching) {
+               if (sc->sc_mode == WSDISPLAYIO_MODE_DUMBFB &&
+                   sc->sc_uobj == NULL) {
+                       mutex_exit(&sc->sc_cond_mtx);
+                       ssdfb_udv_attach(sc);
+                       mutex_enter(&sc->sc_cond_mtx);
+               }
                if (!ssdfb_is_modified(sc)) {
                        if (cv_timedwait(&sc->sc_cond, &sc->sc_cond_mtx,
                            sc->sc_mode == WSDISPLAYIO_MODE_EMUL
diff -r 86e8c71ea7bd -r 1e29a65c2104 sys/dev/ic/ssdfbvar.h
--- a/sys/dev/ic/ssdfbvar.h     Sun Mar 17 01:47:57 2019 +0000
+++ b/sys/dev/ic/ssdfbvar.h     Sun Mar 17 04:03:17 2019 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: ssdfbvar.h,v 1.1 2019/03/17 00:57:15 tnn Exp $ */
+/* $NetBSD: ssdfbvar.h,v 1.2 2019/03/17 04:03:17 tnn Exp $ */
 
 /*
  * Copyright (c) 2019 The NetBSD Foundation, Inc.
@@ -225,6 +225,7 @@
        bool                            sc_detaching;
        int                             sc_backoff;
        bool                            sc_modified;
+       struct uvm_object               *sc_uobj;
 
        /* reference to bus-specific code */
        void    *sc_cookie;