Module Name: src
Committed By: christos
Date: Sun Jan 24 01:44:12 UTC 2021
Modified Files:
src/sys/dev/pci: virtio_pci.c
Log Message:
Add a comment explaining why bus_space_write_8 is limited to virtio.
To generate a diff of this commit:
cvs rdiff -u -r1.19 -r1.20 src/sys/dev/pci/virtio_pci.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/pci/virtio_pci.c
diff -u src/sys/dev/pci/virtio_pci.c:1.19 src/sys/dev/pci/virtio_pci.c:1.20
--- src/sys/dev/pci/virtio_pci.c:1.19 Sat Jan 23 15:00:19 2021
+++ src/sys/dev/pci/virtio_pci.c Sat Jan 23 20:44:11 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: virtio_pci.c,v 1.19 2021/01/23 20:00:19 christos Exp $ */
+/* $NetBSD: virtio_pci.c,v 1.20 2021/01/24 01:44:11 christos Exp $ */
/*
* Copyright (c) 2020 The NetBSD Foundation, Inc.
@@ -28,7 +28,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: virtio_pci.c,v 1.19 2021/01/23 20:00:19 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: virtio_pci.c,v 1.20 2021/01/24 01:44:11 christos Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -733,6 +733,12 @@ virtio_pci_read_queue_size_10(struct vir
* written as two 4 byters
*/
#ifndef __HAVE_BUS_SPACE_8
+/*
+ * This is not a general purpose function that can be used in any
+ * driver. Virtio specifically allows the 8 byte bus transaction
+ * to be split into two 4 byte transactions. Do not copy/use it
+ * in other device drivers unless you know that the device accepts it.
+ */
static __inline void
bus_space_write_8(bus_space_tag_t iot, bus_space_handle_t ioh,
bus_size_t offset, uint64_t value)
