When using sun4 PROM I/O routines, make sure we never attempt to transfer more

than the maximum DMA transfer size the PROM reports.

Crank version to 2.9.

diff --git a/sys/arch/sparc/stand/common/promdev.c b/sys/arch/sparc/stand/common/promdev.c
index 34bbda2..afe89c9 100644 (file)
--- a/sys/arch/sparc/stand/common/promdev.c
+++ b/sys/arch/sparc/stand/common/promdev.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: promdev.c,v 1.16 2015/01/11 15:29:03 miod Exp $       */
+/*     $OpenBSD: promdev.c,v 1.17 2015/01/11 18:10:33 miod Exp $       */
 /*     $NetBSD: promdev.c,v 1.16 1995/11/14 15:04:01 pk Exp $ */
 
 /*
@@ -221,12 +221,15 @@ prom0_strategy(devdata, flag, dblk, size, buf, rsize)
        struct promdata *pd = devdata;
        struct saioreq  *si;
        struct om_boottable *ops;
-       char    *dmabuf;
-       int     si_flag;
-       size_t  xcnt;
+       struct devinfo *dip;
+       char *dmabuf;
+       int si_flag;
+       size_t  xcnt, total, chunk;
+       int rc = 0;
 
        si = pd->si;
        ops = si->si_boottab;
+       dip = ops->b_devinfo;
 
 #ifdef DEBUG_PROM
        printf("prom_strategy: size=%d dblk=%d\n", size, dblk);
@@ -234,23 +237,51 @@ prom0_strategy(devdata, flag, dblk, size, buf, rsize)
 
        dmabuf = dvma_mapin(buf, size);
 
-       si->si_bn = dblk;
-       si->si_ma = dmabuf;
-       si->si_cc = size;
+       /*
+        * Clamp I/O to the maximum DMA transfer size supported by the PROM,
+        * if necessary. Note that we need to round down to a block boundary
+        * as the value is not necessarily a power of two (8216 has been
+        * seen with PROM rev 1.3.)
+        */
+       if (dip->d_dmabytes != 0)
+               chunk = dbtob(btodb(dip->d_dmabytes));
+       else
+               chunk = size;
+
+       total = 0;
+       while (size != 0) {
+               if (size < chunk)
+                       chunk = size;
 
-       si_flag = (flag == F_READ) ? SAIO_F_READ : SAIO_F_WRITE;
-       xcnt = (*ops->b_strategy)(si, si_flag);
-       dvma_mapout(dmabuf, size);
+               si->si_bn = dblk;
+               si->si_ma = dmabuf;
+               si->si_cc = chunk;
+
+               si_flag = (flag == F_READ) ? SAIO_F_READ : SAIO_F_WRITE;
+               xcnt = (*ops->b_strategy)(si, si_flag);
 
 #ifdef DEBUG_PROM
-       printf("disk_strategy: xcnt = %x\n", xcnt);
+               printf("disk_strategy: xcnt = %x\n", xcnt);
 #endif
 
-       if (xcnt <= 0)
-               return (EIO);
+               if (xcnt <= 0) {
+                       rc = EIO;
+                       break;
+               }
 
-       *rsize = xcnt;
-       return (0);
+               total += xcnt;
+               if (xcnt != chunk)
+                       break;
+
+               size -= chunk;
+               dmabuf += chunk;
+               dblk += btodb(chunk);
+       }
+
+       dvma_mapout(dmabuf, size);
+
+       *rsize = total;
+       return rc;
 }
 
 int

diff --git a/sys/arch/sparc/stand/common/version.c b/sys/arch/sparc/stand/common/version.c
index 565b578..177a2d3 100644 (file)
--- a/sys/arch/sparc/stand/common/version.c
+++ b/sys/arch/sparc/stand/common/version.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: version.c,v 1.9 2014/03/30 19:48:04 miod Exp $        */
+/*     $OpenBSD: version.c,v 1.10 2015/01/11 18:10:33 miod Exp $       */
 /*     $NetBSD: version.c,v 1.4 1995/09/16 23:20:39 pk Exp $ */
 
 /*
@@ -49,6 +49,7 @@
  *             stomping on PROM data below 4MB on sun4c
  *     2.7     /etc/random.seed support
  *     2.8     Fix network boot broken on some PROM by the 2.7 changes
+ *     2.9     Cope with DMA transfer size limits of old sun4 PROMs
  */
 
-char *version = "2.8";
+char *version = "2.9";