[src/trunk]: src/sys/dev/sbus allow mmap()ing blitter registers

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

details:   https://anonhg.NetBSD.org/src/rev/50be6a405f4f
branches:  trunk
changeset: 814069:50be6a405f4f
user:      macallan <macallan%NetBSD.org@localhost>
date:      Fri Mar 04 22:08:09 2016 +0000

description:
allow mmap()ing blitter registers

diffstat:

 sys/dev/sbus/mgx.c |  55 +++++++++++++++++++++++++++++++++++++++++------------
 1 files changed, 42 insertions(+), 13 deletions(-)

diffs (127 lines):

diff -r 6df32bf804b7 -r 50be6a405f4f sys/dev/sbus/mgx.c
--- a/sys/dev/sbus/mgx.c        Fri Mar 04 18:52:01 2016 +0000
+++ b/sys/dev/sbus/mgx.c        Fri Mar 04 22:08:09 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: mgx.c,v 1.7 2016/02/25 17:09:39 joerg Exp $ */
+/*     $NetBSD: mgx.c,v 1.8 2016/03/04 22:08:09 macallan Exp $ */
 
 /*-
  * Copyright (c) 2014 Michael Lorenz
@@ -29,7 +29,7 @@
 /* a console driver for the SSB 4096V-MGX graphics card */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: mgx.c,v 1.7 2016/02/25 17:09:39 joerg Exp $");
+__KERNEL_RCSID(0, "$NetBSD: mgx.c,v 1.8 2016/03/04 22:08:09 macallan Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -38,6 +38,7 @@
 #include <sys/ioctl.h>
 #include <sys/conf.h>
 #include <sys/kmem.h>
+#include <sys/kauth.h>
 
 #include <sys/bus.h>
 #include <machine/autoconf.h>
@@ -65,7 +66,7 @@
        bus_space_tag_t sc_tag;
        bus_space_handle_t sc_blith;
        bus_space_handle_t sc_vgah;
-       bus_addr_t      sc_paddr;
+       bus_addr_t      sc_paddr, sc_rpaddr;
        void            *sc_fbaddr;
        uint8_t         *sc_cursor;
        int             sc_width;
@@ -159,6 +160,14 @@
        return bus_space_read_1(sc->sc_tag, sc->sc_blith, reg ^ 3);
 }
 
+#if 0
+static inline uint32_t
+mgx_read_4(struct mgx_softc *sc, uint32_t reg)
+{
+       return bus_space_read_4(sc->sc_tag, sc->sc_blith, reg);
+}
+#endif
+
 static inline void
 mgx_write_2(struct mgx_softc *sc, uint32_t reg, uint16_t val)
 {
@@ -202,6 +211,8 @@
 
        sc->sc_paddr = sbus_bus_addr(sa->sa_bustag, sa->sa_slot,
            sa->sa_reg[8].oa_base);
+       sc->sc_rpaddr = sbus_bus_addr(sa->sa_bustag, sa->sa_slot,
+           sa->sa_reg[5].oa_base + MGX_REG_ATREG_OFFSET);
 
        /* read geometry information from the device tree */
        sc->sc_width = prom_getpropint(sa->sa_node, "width", 1152);
@@ -311,17 +322,14 @@
        config_found(self, &aa, wsemuldisplaydevprint);
 
 #if 0
-       uint32_t *fb = sc->sc_fbaddr;
-       int i, j;
-       for (i = 0; i < 256; i += 16) {
-               printf("%04x:", i);
-               for (j = 0; j < 16; j += 4) {
-                       printf(" %08x", fb[(i + j) >> 2]);
-               }
-               printf("\n");
+       {
+               uint32_t ap;
+               /* reads 0xfd210000 */
+               mgx_write_4(sc, ATR_APERTURE, 0x00000000); 
+               ap = mgx_read_4(sc, ATR_APERTURE);
+               printf("aperture: %08x\n", ap);
        }
 #endif
-
 }
 
 static void
@@ -659,6 +667,10 @@
                mgx_wait_engine(sc);
                sc->sc_putchar(cookie, row, col, c, attr & ~1);
                if (rv == GC_ADD) {
+                       /*
+                        * try to make sure the glyph made it all the way to
+                        * video memory before trying to blit it into the cache
+                        */ 
                        junk = *(uint32_t *)sc->sc_fbaddr;
                        __USE(junk);
                        glyphcache_add(&sc->sc_gc, c, x, y);
@@ -922,7 +934,7 @@
                case WSDISPLAYIO_GET_FBINFO:
                        {
                                struct wsdisplayio_fbinfo *fbi = data;
-                               
+       
                                fbi->fbi_fbsize = sc->sc_fbsize - 1024;
                                fbi->fbi_width = sc->sc_width;
                                fbi->fbi_height = sc->sc_height;
@@ -955,6 +967,23 @@
                    offset, prot, BUS_SPACE_MAP_LINEAR);
        }
 
+       /*
+        * Blitter registers at 0x80000000, only in mapped mode.
+        * Restrict to root, even though I'm fairly sure the DMA engine lives
+        * elsewhere ( and isn't documented anyway )
+        */
+       if (kauth_authorize_machdep(kauth_cred_get(),
+           KAUTH_MACHDEP_UNMANAGEDMEM,
+           NULL, NULL, NULL, NULL) != 0) {
+               aprint_normal("%s: mmap() rejected.\n",
+                   device_xname(sc->sc_dev));
+               return -1;
+       }
+       if ((sc->sc_mode == WSDISPLAYIO_MODE_MAPPED) &&
+           (offset >= 0x80000000) && (offset < 0x80001000)) {
+               return bus_space_mmap(sc->sc_tag, sc->sc_rpaddr,
+                   offset, prot, BUS_SPACE_MAP_LINEAR);
+       }
        return -1;
 }