bug fix from greg -- calling ubamem out of order can result in

[unix-history] / usr / src / sys / vax / uba / uba.c

diff --git a/usr/src/sys/vax/uba/uba.c b/usr/src/sys/vax/uba/uba.c
index 7afddb6..7567e75 100644 (file)
--- a/usr/src/sys/vax/uba/uba.c
+++ b/usr/src/sys/vax/uba/uba.c
@@ -1,4 +1,4 @@
-/*     uba.c   6.1     83/07/31        */
+/*     uba.c   4.62    83/08/21        */

 
 #include "../machine/pte.h"
 
 
 #include "../machine/pte.h"
 


@@ -428,42 +428,46 @@ ubaerror(uban, uh, xx, uvec, uba)
 #endif
 
 /*
 #endif
 
 /*

- * This routine is called by a driver for a device with on-board Unibus
- * memory.  It removes the memory block from the Unibus resource map
- * and clears the map registers for the block.
- *
- * Arguments are the Unibus number, the Unibus address of the memory
- * block, its size in blocks of 512 bytes, and a flag indicating whether
- * to allocate the unibus space form the resource map or whether it already
- * has been.
- *
- * Returns > 0 if successful, 0 if not.
+ * Allocate UNIBUS memory.  Allocates and initializes
+ * sufficient mapping registers for access.  On a 780,
+ * the configuration register is setup to disable UBA
+ * response on DMA transfers to addresses controlled
+ * by the disabled mapping registers.

  */
  */

-ubamem(uban, addr, size, doalloc)
-       int uban, addr, size, doalloc;
+ubamem(uban, addr, npg, doalloc)
+       int uban, addr, npg, doalloc;

 {
        register struct uba_hd *uh = &uba_hd[uban];
 {
        register struct uba_hd *uh = &uba_hd[uban];

-       register int *m;
-       register int i, a, s;
+       register int a;

 
        if (doalloc) {
 
        if (doalloc) {

-               s = spl6();
-               a = rmget(uh->uh_map, size, (addr>>9)+1); /* starts at ONE! */
+               int s = spl6();
+               a = rmget(uh->uh_map, npg, (addr >> 9) + 1);

                splx(s);
        } else
                splx(s);
        } else

-               a = (addr>>9)+1;
+               a = (addr >> 9) + 1;

        if (a) {
        if (a) {

-               m = (int *) &uh->uh_uba->uba_map[a-1];
-               for (i=0; i<size; i++)
+               register int i, *m;
+
+               m = (int *)&uh->uh_uba->uba_map[a - 1];
+               for (i = 0; i < npg; i++)

                        *m++ = 0;       /* All off, especially 'valid' */
 #if VAX780
                        *m++ = 0;       /* All off, especially 'valid' */
 #if VAX780

-               if (cpu == VAX_780) {           /* map disable */
-                       i = (addr+size*512+8191)/8192;
-                       uh->uh_uba->uba_cr |= i<<26;
+               /*
+                * On a 780, set up the map register disable
+                * field in the configuration register.  Beware
+                * of callers that request memory ``out of order''.
+                */
+               if (cpu == VAX_780) {
+                       int cr = uh->uh_uba->uba_cr;
+
+                       i = (addr + npg * 512 + 8191) / 8192;
+                       if (i > (cr >> 26))
+                               uh->uh_uba->uba_cr |= i << 26;

                }
 #endif
        }
                }
 #endif
        }

-       return(a);
+       return (a);

 }
 
 #include "ik.h"
 }
 
 #include "ik.h"