CV-Bowen opened a new pull request, #21314:
URL: https://github.com/apache/nuttx/pull/21314
## Summary
The two cores of a BMP link share one resource table and only one of
them initializes it; which one depends on the board.
`rptun_bmp_get_resource()` returned the table right away, so the core
that does not own it could start parsing an uninitialized table, find
no vdev and never bring up the link.
Wait in `rptun_bmp_get_resource()` until the table header has a non-zero
version. Both roles wait, because the table can be set up by either the
master or the slave.
## Impact
`rptun_bmp_get_resource()` blocks until the peer has initialized the
resource table, instead of returning a table that may not be ready. No
API or Kconfig change.
## Testing
Host: Ubuntu 22.04.5 LTS x86_64, QEMU version 10.2.1, sim: cc (Ubuntu
13.1.0-8ubuntu1~22.04) 13.1.0, qemu-armv8a: aarch64-none-elf-gcc (Arm GNU
Toolchain 12.2.Rel1 (Build arm-12.24)) 12.2.1 20221205
No in-tree board uses rptun_bmp. It was run on an out-of-tree QEMU
armv7-a TrustZone setup (`-machine virt,secure=on`): the secure world
(TEE, rptun_bmp slave) initializes the resource table and the
non-secure world (AP, rptun_bmp master) reads it. The images were built
from a tree whose `rptun_bmp_get_resource()` is identical to this PR.
The link comes up and rpmsg works across it:
<details><summary>AP console</summary>
```
ap> ls /dev/rptun
/dev/rptun:
tee
ap> rpmsg dump all
[ 18.536112] [12] [ EMERG] [ap] rpmsg_virtio_dump: Local: ap Remote: tee
Headrx 20 Headtx 12
[ 18.536264] [12] [ EMERG] [ap] rpmsg_virtio_dump: Dump rpmsg info between
cpu (master: yes)ap <==> tee:
[ 18.536323] [12] [ EMERG] [ap] rpmsg_dump_epts: rpmsg ept list:
[ 18.536382] [12] [ EMERG] [ap] rpmsg_dump_epts: ept NS 0x404bfc40: s=53
d=53 r=1 pr=127 p=0x404bfc38
[ 18.536449] [12] [ EMERG] [ap] rpmsg_dump_epts: ept rpmsg-rtc
0x404a05e0: s=1024 d=1029 r=1 pr=127 p=0x4049bf00
[ 18.536480] [12] [ EMERG] [ap] rpmsg_dump_epts: ept rpmsg-ttyTEE
0x404a2e90: s=1025 d=1025 r=1 pr=255 p=0x4049ed58
[ 18.536508] [12] [ EMERG] [ap] rpmsg_dump_epts: ept rpmsg-sensor
0x404a2628: s=1026 d=4294967295 r=1 pr=127 p=0x404a2620
[ 18.536722] [12] [ EMERG] [ap] rpmsg_dump_epts: ept rpmsg-ping
0x404bfb88: s=1027 d=1027 r=1 pr=127 p=0
[ 18.536766] [12] [ EMERG] [ap] rpmsg_dump_epts: ept rpmsg-ping-rt
0x404bfbd8: s=1028 d=1028 r=1 pr=255 p=0
[ 18.536793] [12] [ EMERG] [ap] rpmsg_dump_epts: ept rpmsg-syslog
0x404c34a0: s=1029 d=1024 r=1 pr=126 p=0x404c34a0
ap> rpmsg ping all 3 64 3 0
[ 24.593303] [12] [ EMERG] [ap] rpmsg_ping: core info: ap <-> tee
[ 24.593341] [12] [ EMERG] [ap] rpmsg_ping: ping times: 3
[ 24.593370] [12] [ EMERG] [ap] rpmsg_ping: buffer_len: 496, send_len: 64
[ 24.593514] [12] [ EMERG] [ap] rpmsg_ping_logout: avg: 0 s, 5908464 ns
[ 24.593563] [12] [ EMERG] [ap] rpmsg_ping_logout: min: 0 s, 1543152 ns
[ 24.593611] [12] [ EMERG] [ap] rpmsg_ping_logout: max: 0 s, 13517232 ns
[ 24.593752] [12] [ EMERG] [ap] rpmsg_ping_logout_rate: rate: 0.086655
Mbits/sec
```
</details>
In this setup the secure side initializes the table before it starts
the non-secure side, so the wait returns at once; the case it protects
against is the owner of the table starting after its peer.
`rptun_bmp.c` was also built for qemu-armv8a:rpserver with
`CONFIG_RPTUN_BMP=y` added, without warnings. Baseline:
Baseline (`test.sh`, cases: baseline.yaml):
- host: Ubuntu 22.04.5 LTS x86_64, QEMU version 10.2.1, sim: cc (Ubuntu
13.1.0-8ubuntu1~22.04) 13.1.0, qemu-armv8a: aarch64-none-elf-gcc (Arm GNU
Toolchain 12.2.Rel1 (Build arm-12.24)) 12.2.1 20221205
- tested: nuttx ea042dd8c39 apps 35cdcc9a8
- qemu-armv8a built with test-only overlay: disabled LIBC_ENVPATH
BINFMT_CHECKEXEC
- sim:rpserver + sim:rpproxy: PASS
- [x] `uname -a` (server)
- [x] `rpmsg dump all` (server)
- [x] `rpmsg ping all 10 1024 3 0` (server)
- [x] `uname -a` (proxy)
- [x] `rpmsg ping all 10 1024 3 0` (proxy)
- [x] `mount -t rpmsgfs -o cpu=server,fs=/proc /sp` (proxy)
- [x] `cat /sp/version` (proxy)
- [x] `rpmsg dump all` (proxy)
- qemu-armv8a:rpserver + qemu-armv8a:rpproxy: PASS
- [x] `uname -a` (server)
- [x] `uname -a` (proxy)
- [x] `rpmsg dump all` (server)
- [x] `rpmsg ping all 10 1024 3 0` (server)
- [x] `rpmsg ping all 10 1024 3 0` (proxy)
- [x] `mount -t rpmsgfs -o cpu=server,fs=/proc /sp` (proxy)
- [x] `cat /sp/version` (proxy)
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
