PR/59654 CVS commit: [netbsd-10] src/sys/arch/arm

["Martin Husemann" <martin%netbsd.org@localhost>]

The following reply was made to PR port-arm/59654; it has been noted by GNATS.

From: "Martin Husemann" <martin%netbsd.org@localhost>
To: gnats-bugs%gnats.NetBSD.org@localhost
Cc: 
Subject: PR/59654 CVS commit: [netbsd-10] src/sys/arch/arm
Date: Wed, 1 Oct 2025 16:54:19 +0000

 Module Name:	src
 Committed By:	martin
 Date:		Wed Oct  1 16:54:19 UTC 2025
 
 Modified Files:
 	src/sys/arch/arm/arm32 [netbsd-10]: bus_dma.c
 	src/sys/arch/arm/include [netbsd-10]: cpufunc.h
 
 Log Message:
 Pull up following revision(s) (requested by skrll in ticket #1166):
 
 	sys/arch/arm/arm32/bus_dma.c: revision 1.142
 	sys/arch/arm/include/cpufunc.h: revision 1.92
 	sys/arch/arm/arm32/bus_dma.c: revision 1.150
 
 More KNF
 
 arm: Adjust barriers issued in bus_dmamap_sync for the coherent case.
 PR/59654
 
 This change adjusts the memory barriers issued by bus_dmamap_sync for
 the coherent case. In the non-coherent case the CPU cache operations
 are expected to provide any, and all required barriers.
 
 These barriers are emitted after bouncing for PREWRITE and before
 bouncing for POSTREAD.
 
 A new indrection is introduced to deal with the differencs in barrier
 (dsb) options between Arm V8 and V7, the lack of options in Arm V6,
 and the need to use cpu_drain_writebuf for all other earlier versions.
 
 The Arm V8 Net change is:
 op                      old                     new
 ---------------------   ----------------------  ------------
 PREREAD                 none                    dsb(osh)
 PREWRITE                cpu_drain_writebuf      dsb(oshst)
 PREREAD|PREWRITE        cpu_drain_writebuf      dsb(osh)
 POSTREAD                cpu_drain_writebuf      dsb(oshld)
 POSTWRITE               none                    none
 POSTREAD|POSTWRITE      cpu_drain_writebuf      dsb(oshld)
 where cpu_drain_writebuf is a dsb(sy) or CPU equivalent.
 
 
 To generate a diff of this commit:
 cvs rdiff -u -r1.138 -r1.138.2.1 src/sys/arch/arm/arm32/bus_dma.c
 cvs rdiff -u -r1.90 -r1.90.4.1 src/sys/arch/arm/include/cpufunc.h
 
 Please note that diffs are not public domain; they are subject to the
 copyright notices on the relevant files.