PERFORCE change 93678 for review

[Kip Macy]

http://perforce.freebsd.org/chv.cgi?CH=93678

Change 93678 by kmacy at kmacy_storage:sun4vtmp on 2006/03/21 02:59:36

	handle non page-aligned reads that straddle physical pages

Affected files ...

.. //depot/projects/kmacy_sun4v/src/sys/sun4v/sun4v/simdisk.c#3 edit

Differences ...

==== //depot/projects/kmacy_sun4v/src/sys/sun4v/sun4v/simdisk.c#3 (text+ko) ====

@@ -89,20 +89,34 @@
 hvd_startio(struct hvd_softc *sc, struct bio *bp)
 {
 	u_int r;
-	int len;
+	int len, rlen, wlen;
+	uint64_t page_off;
+
 	r = H_EOK;
+	len = 0;
+
+	page_off = bp->bio_offset & PAGE_MASK;
+
 
         switch (bp->bio_cmd) {
         case BIO_READ:
-		for (len = 0; len < bp->bio_length && r == H_EOK; len += PAGE_SIZE) {
-			int rlen = (bp->bio_length - len) > PAGE_SIZE ? PAGE_SIZE : bp->bio_length - len;
+		if (bp->bio_length > (PAGE_SIZE - page_off)) {
+			len = rlen = (PAGE_SIZE - page_off);
+			r = hv_sim_read(bp->bio_offset, vtophys((char *)bp->bio_data), rlen);
+		}
+		for (; len < bp->bio_length && r == H_EOK; len += PAGE_SIZE) {
+			rlen = (bp->bio_length - len) > PAGE_SIZE ? PAGE_SIZE : bp->bio_length - len;
 			r = hv_sim_read(bp->bio_offset + len, vtophys((char *)bp->bio_data + len), rlen);
 
 		}
                 break;
         case BIO_WRITE:
-		for (len = 0; len < bp->bio_length && r == H_EOK; len += PAGE_SIZE) {
-			int wlen = (bp->bio_length - len) > PAGE_SIZE ? PAGE_SIZE : bp->bio_length - len;
+		if (bp->bio_length > (PAGE_SIZE - page_off)) {
+			len = wlen = (PAGE_SIZE - page_off);
+			r = hv_sim_write(bp->bio_offset, vtophys((char *)bp->bio_data), wlen);
+		}
+		for (; len < bp->bio_length && r == H_EOK; len += PAGE_SIZE) {
+			wlen = (bp->bio_length - len) > PAGE_SIZE ? PAGE_SIZE : bp->bio_length - len;
 			r = hv_sim_write(bp->bio_offset + len, vtophys((char *)bp->bio_data + len), wlen);
 		}
                 break;