Module Name: src
Committed By: reinoud
Date: Fri Feb 5 19:18:23 UTC 2021
Modified Files:
src/sys/dev/pci: virtio.c virtio_pci.c virtiovar.h
Log Message:
Second round of cleaning up endian code. No more tailored code to maintain.
To generate a diff of this commit:
cvs rdiff -u -r1.45 -r1.46 src/sys/dev/pci/virtio.c
cvs rdiff -u -r1.27 -r1.28 src/sys/dev/pci/virtio_pci.c
cvs rdiff -u -r1.19 -r1.20 src/sys/dev/pci/virtiovar.h
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.c
diff -u src/sys/dev/pci/virtio.c:1.45 src/sys/dev/pci/virtio.c:1.46
--- src/sys/dev/pci/virtio.c:1.45 Thu Jan 28 15:43:12 2021
+++ src/sys/dev/pci/virtio.c Fri Feb 5 19:18:23 2021
@@ -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 @@ virtio_read_device_config_4(struct virti
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;
+
+ for (int i = 0; i < 8; i++)
+ v.b[i] = bus_space_read_1(iot, ioh, index + i);
+ val = v.u64;
- 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;
- }
-
-#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 @@ virtio_write_device_config_4(struct virt
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;
-
- val_l = BUS_ADDR_LO32(value);
- val_h = BUS_ADDR_HI32(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);
+ union {
+ uint64_t u64;
+ uint8_t b[8];
+ } v;
+
+ if (BYTE_ORDER != sc->sc_struct_endian)
+ value = bswap64(value);
+
+ 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]);
}
/*
Index: src/sys/dev/pci/virtio_pci.c
diff -u src/sys/dev/pci/virtio_pci.c:1.27 src/sys/dev/pci/virtio_pci.c:1.28
--- src/sys/dev/pci/virtio_pci.c:1.27 Thu Jan 28 15:43:12 2021
+++ src/sys/dev/pci/virtio_pci.c Fri Feb 5 19:18:23 2021
@@ -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 @@ static int virtio_pci_setup_intx_interru
* 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 @@ virtio_pci_attach_09(device_t self, void
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;
}
Index: src/sys/dev/pci/virtiovar.h
diff -u src/sys/dev/pci/virtiovar.h:1.19 src/sys/dev/pci/virtiovar.h:1.20
--- src/sys/dev/pci/virtiovar.h:1.19 Thu Jan 28 15:43:12 2021
+++ src/sys/dev/pci/virtiovar.h Fri Feb 5 19:18:23 2021
@@ -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 @@ struct virtio_softc {
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;
