CVS commit: src/sys/dev/pci

["Rin Okuyama" <rin%netbsd.org@localhost>]

Module Name:    src
Committed By:   rin
Date:           Tue Nov  7 13:38:01 UTC 2023

Modified Files:
        src/sys/dev/pci: virtio.c

Log Message:
virtio_read_device_config_le_[24]: Fix for {aarch64,arm}eb

Stop byte-swapping for big-endian aarch64 and arm to fix
corrupted read for, e.g., sc_taglen for vio9p(4).

As described as comments in virtio_pci.c, big-endian aarch64 and
armv7 (armeb) are somewhat special. At the moment, all supported
virtual/real machines are configured as little-endian, and only
CPU cores are switched to big-endian mode during early boot stage.

Most peripheral buses for armeb are LSB as a result, and their
default bus_space(9) functions swap byte-order. Therefore, PIOed
data from memory-mapped devices, as well as pci(4) ones, are
actually LSB, but observed as MSB for armeb.

Therefore, we should not swap byte-order further in
virtio_read_device_config_le_[24] on armeb.

Thanks ozaki-r@ for comments.

XXX Centralize?
See virtio_pci.c and sys/dev/fdt/virtio_mmio_fdt.c also.


To generate a diff of this commit:
cvs rdiff -u -r1.78 -r1.79 src/sys/dev/pci/virtio.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.