CVS commit: src/sys/arch/m68k/m68k

["Jason R Thorpe" <thorpej%netbsd.org@localhost>]

Module Name:    src
Committed By:   thorpej
Date:           Thu Nov 27 21:26:04 UTC 2025

Modified Files:
        src/sys/arch/m68k/m68k: pmap_68k.c

Log Message:
When entering an EXEC mapping on 68040-class MMUs, we need to make sure
to push the page from the D-cache to handle the following situation:

Page was brought into memory over some mechanism that has the CPU
touch the page (e.g. paging in binary over NFS root, with an "le"
network interface).  The page is cached write-back, and so when the
user-space EXEC mapping of the page is entered, the data may still
be lingering in the cache and not yet made it out to main memory,
so when the I-cache loads from the page, it gets stale data.

XXX In addition to the DCFP(), we also do an ICPP() because that's what
Hibler's pmap did.  The ICPP() is probably not necessary.  This is an
area for future optimiation.

XXX We really only need to do this if there are not already EXEC mappings
of a managed page.  This is a possible area for future optimization.

Issue analysed and fix proposed by tsutsui@.  This is a slightly tweaked
version of that change.


To generate a diff of this commit:
cvs rdiff -u -r1.33 -r1.34 src/sys/arch/m68k/m68k/pmap_68k.c

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