Source-Changes-HG archive
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]
[src/trunk]: src/sys/dev/pci Second round of cleaning up endian code. No more...
details: https://anonhg.NetBSD.org/src/rev/7403d599f18a
branches: trunk
changeset: 951535:7403d599f18a
user: reinoud <reinoud%NetBSD.org@localhost>
date: Fri Feb 05 19:18:23 2021 +0000
description:
Second round of cleaning up endian code. No more tailored code to maintain.
diffstat:
sys/dev/pci/virtio.c | 79 +++++++++++++++++++++--------------------------
sys/dev/pci/virtio_pci.c | 15 ++------
sys/dev/pci/virtiovar.h | 5 +--
3 files changed, 41 insertions(+), 58 deletions(-)
diffs (185 lines):
diff -r 50d2dea4910a -r 7403d599f18a sys/dev/pci/virtio.c
--- a/sys/dev/pci/virtio.c Fri Feb 05 17:20:32 2021 +0000
+++ b/sys/dev/pci/virtio.c Fri Feb 05 19:18:23 2021 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: virtio.c,v 1.45 2021/01/28 15:43:12 reinoud Exp $ */
+/* $NetBSD: virtio.c,v 1.46 2021/02/05 19:18:23 reinoud Exp $ */
/*
* Copyright (c) 2020 The NetBSD Foundation, Inc.
@@ -28,7 +28,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: virtio.c,v 1.45 2021/01/28 15:43:12 reinoud Exp $");
+__KERNEL_RCSID(0, "$NetBSD: virtio.c,v 1.46 2021/02/05 19:18:23 reinoud Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -201,32 +201,27 @@
return val;
}
+/*
+ * The Virtio spec explicitly tells that reading and writing 8 bytes are not
+ * considered atomic and no triggers may be connected to reading or writing
+ * it. This allows for reading byte-by-byte.
+ */
uint64_t
virtio_read_device_config_8(struct virtio_softc *sc, int index) {
bus_space_tag_t iot = sc->sc_devcfg_iot;
bus_space_handle_t ioh = sc->sc_devcfg_ioh;
- uint64_t val, val_0, val_1, val_l, val_h;
+ union {
+ uint64_t u64;
+ uint8_t b[8];
+ } v;
+ uint64_t val;
- val_0 = bus_space_read_4(iot, ioh, index);
- val_1 = bus_space_read_4(iot, ioh, index + 4);
- if (BYTE_ORDER != sc->sc_bus_endian) {
- val_l = bswap32(val_1);
- val_h = bswap32(val_0);
- } else {
- val_l = val_0;
- val_h = val_1;
- }
+ for (int i = 0; i < 8; i++)
+ v.b[i] = bus_space_read_1(iot, ioh, index + i);
+ val = v.u64;
-#ifdef AARCH64EB_PROBLEM
- /* XXX see comment at virtio_pci.c */
- if (sc->sc_aarch64eb_bus_problem) {
- val_l = val_1;
- val_h = val_0;
- }
-#endif
-
- val = val_h << 32;
- val |= val_l;
+ if (BYTE_ORDER != sc->sc_struct_endian)
+ val = bswap64(val);
DPRINTFR("read_8", "%08lx", val, index, 8);
DPRINTFR2("read_8 low ", "%08x",
@@ -308,34 +303,32 @@
bus_space_write_4(iot, ioh, index, value);
}
+/*
+ * The Virtio spec explicitly tells that reading and writing 8 bytes are not
+ * considered atomic and no triggers may be connected to reading or writing
+ * it. This allows for writing byte-by-byte. For good measure it is stated to
+ * always write lsb first just in case of a hypervisor bug.
+ */
void
virtio_write_device_config_8(struct virtio_softc *sc, int index, uint64_t value)
{
bus_space_tag_t iot = sc->sc_devcfg_iot;
bus_space_handle_t ioh = sc->sc_devcfg_ioh;
- uint64_t val_0, val_1, val_l, val_h;
+ union {
+ uint64_t u64;
+ uint8_t b[8];
+ } v;
- val_l = BUS_ADDR_LO32(value);
- val_h = BUS_ADDR_HI32(value);
+ if (BYTE_ORDER != sc->sc_struct_endian)
+ value = bswap64(value);
- if (BYTE_ORDER != sc->sc_bus_endian) {
- val_0 = bswap32(val_h);
- val_1 = bswap32(val_l);
- } else {
- val_0 = val_l;
- val_1 = val_h;
- }
-
-#ifdef AARCH64EB_PROBLEM
- /* XXX see comment at virtio_pci.c */
- if (sc->sc_aarch64eb_bus_problem) {
- val_0 = val_h;
- val_1 = val_l;
- }
-#endif
-
- bus_space_write_4(iot, ioh, index, val_0);
- bus_space_write_4(iot, ioh, index + 4, val_1);
+ v.u64 = value;
+ if (sc->sc_struct_endian == LITTLE_ENDIAN)
+ for (int i = 0; i < 8; i++)
+ bus_space_write_1(iot, ioh, index + i, v.b[i]);
+ else
+ for (int i = 7; i >= 0; i--)
+ bus_space_write_1(iot, ioh, index + i, v.b[i]);
}
/*
diff -r 50d2dea4910a -r 7403d599f18a sys/dev/pci/virtio_pci.c
--- a/sys/dev/pci/virtio_pci.c Fri Feb 05 17:20:32 2021 +0000
+++ b/sys/dev/pci/virtio_pci.c Fri Feb 05 19:18:23 2021 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: virtio_pci.c,v 1.27 2021/01/28 15:43:12 reinoud Exp $ */
+/* $NetBSD: virtio_pci.c,v 1.28 2021/02/05 19:18:23 reinoud Exp $ */
/*
* Copyright (c) 2020 The NetBSD Foundation, Inc.
@@ -28,7 +28,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: virtio_pci.c,v 1.27 2021/01/28 15:43:12 reinoud Exp $");
+__KERNEL_RCSID(0, "$NetBSD: virtio_pci.c,v 1.28 2021/02/05 19:18:23 reinoud Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -127,15 +127,11 @@
* suddenly read BIG_ENDIAN where it should stay LITTLE_ENDIAN. The data read
* 1 byte at a time seem OK but reading bigger lengths result in swapped
* endian. This is most notable on reading 8 byters since we can't use
- * bus_space_{read,write}_8() and it has to be patched there explicitly. We
- * define the AARCH64EB_PROBLEM to signal we're vulnerable to this and set the
- * accompanied sc->sc_aarch64_eb_bus_problem variable when attaching using the
- * IO space.
+ * bus_space_{read,write}_8().
*/
#if defined(__aarch64__) && BYTE_ORDER == BIG_ENDIAN
- /* source of AARCH64EB_PROBLEM */
-# define READ_ENDIAN_09 BIG_ENDIAN /* XXX bug, should be LITTLE_ENDIAN */
+# define READ_ENDIAN_09 BIG_ENDIAN /* should be LITTLE_ENDIAN */
# define READ_ENDIAN_10 BIG_ENDIAN
# define STRUCT_ENDIAN_09 BIG_ENDIAN
# define STRUCT_ENDIAN_10 LITTLE_ENDIAN
@@ -369,9 +365,6 @@
sc->sc_ops = &virtio_pci_ops_09;
sc->sc_bus_endian = READ_ENDIAN_09;
sc->sc_struct_endian = STRUCT_ENDIAN_09;
-#if defined(__aarch64__) && BYTE_ORDER == BIG_ENDIAN
- sc->sc_aarch64eb_bus_problem = true;
-#endif
return 0;
}
diff -r 50d2dea4910a -r 7403d599f18a sys/dev/pci/virtiovar.h
--- a/sys/dev/pci/virtiovar.h Fri Feb 05 17:20:32 2021 +0000
+++ b/sys/dev/pci/virtiovar.h Fri Feb 05 19:18:23 2021 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: virtiovar.h,v 1.19 2021/01/28 15:43:12 reinoud Exp $ */
+/* $NetBSD: virtiovar.h,v 1.20 2021/02/05 19:18:23 reinoud Exp $ */
/*
* Copyright (c) 2010 Minoura Makoto.
@@ -148,9 +148,6 @@
const struct virtio_ops *sc_ops;
bus_dma_tag_t sc_dmat;
-#define AARCH64EB_PROBLEM /* see comment in virtio_pci.c */
- bool sc_aarch64eb_bus_problem;
-
int sc_bus_endian;
int sc_struct_endian;
Home |
Main Index |
Thread Index |
Old Index