From d3e82ec52862cbf0dc9aaa9b40b852d0cc74a721 Mon Sep 17 00:00:00 2001
From: "Federico G. Schwindt" <fgsch@cvs.openbsd.org>
Date: Wed, 3 Aug 2005 23:08:23 +0000
Subject: enforce 10-bit width for i/o addresses when start address is assigned
 by the driver and calcule address line mask when is not.  from
 haya@netbsd.org. tested by several ppl.

---
 sys/dev/pci/pccbb.c | 36 ++++++++++++++++++++++++++++++++----
 1 file changed, 32 insertions(+), 4 deletions(-)

(limited to 'sys')

diff --git a/sys/dev/pci/pccbb.c b/sys/dev/pci/pccbb.c
index 7d2f064f439..6e837d6cc64 100644
--- a/sys/dev/pci/pccbb.c
+++ b/sys/dev/pci/pccbb.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pccbb.c,v 1.35 2005/01/27 17:03:23 millert Exp $ */
+/*	$OpenBSD: pccbb.c,v 1.36 2005/08/03 23:08:22 fgsch Exp $ */
 /*	$NetBSD: pccbb.c,v 1.96 2004/03/28 09:49:31 nakayama Exp $	*/
 
 /*
@@ -1958,6 +1958,7 @@ pccbb_pcmcia_io_alloc(pch, start, size, align, pcihp)
 	int flags = 0;
 	bus_space_tag_t iot;
 	bus_space_handle_t ioh;
+	bus_addr_t mask;
 #if rbus
 	rbus_tag_t rb;
 #endif
@@ -1965,6 +1966,34 @@ pccbb_pcmcia_io_alloc(pch, start, size, align, pcihp)
 		align = size;	       /* XXX: funny??? */
 	}
 
+	if (start != 0) {
+		/* XXX: assume all card decode lower 10 bits by its hardware */
+		mask = 0x3ff;
+		/* enforce to use only masked address */
+		start &= mask;
+	} else {
+		/*
+		 * calculate mask:
+		 *  1. get the most significant bit of size (call it msb).
+		 *  2. compare msb with the value of size.
+		 *  3. if size is larger, shift msb left once.
+		 *  4. obtain mask value to decrement msb.
+		 */
+		bus_size_t size_tmp = size;	
+		int shifts = 0;
+
+		mask = 1;
+		while (size_tmp) {
+			++shifts;
+			size_tmp >>= 1;
+		}
+		mask = (1 << shifts);
+		if (mask < size) {
+			mask <<= 1;
+		}
+		mask--;
+	}
+
 	/*
 	 * Allocate some arbitrary I/O space.
 	 */
@@ -1973,8 +2002,7 @@ pccbb_pcmcia_io_alloc(pch, start, size, align, pcihp)
 
 #if rbus
 	rb = ((struct pccbb_softc *)(ph->ph_parent))->sc_rbus_iot;
-	/* XXX: I assume all card decode lower 10 bits by its hardware */
-	if (rbus_space_alloc(rb, start, size, 0x3ff, align, 0, &ioaddr, &ioh)) {
+	if (rbus_space_alloc(rb, start, size, mask, align, 0, &ioaddr, &ioh)) {
 		return 1;
 	}
 #else
@@ -1983,7 +2011,7 @@ pccbb_pcmcia_io_alloc(pch, start, size, align, pcihp)
 		if (bus_space_map(iot, start, size, 0, &ioh)) {
 			return 1;
 		}
-		DPRINTF(("pccbb_pcmcia_io_alloc map port %lx+%lx\n",
+		DPRINTF(("pccbb_pcmcia_io_alloc map port 0x%lx+0x%lx\n",
 		    (u_long) ioaddr, (u_long) size));
 	} else {
 		flags |= PCMCIA_IO_ALLOCATED;
-- 
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