Module Name: src Committed By: martin Date: Sun Sep 1 14:03:02 UTC 2019
Modified Files: src/sys/arch/arm/conf [netbsd-9]: Makefile.arm src/sys/dev/usb [netbsd-9]: if_axe.c Log Message: Pull up following revision(s) (requested by rin in ticket #146): sys/arch/arm/conf/Makefile.arm: revision 1.50 sys/dev/usb/if_axe.c: revision 1.120 PR kern/54486 Workaround for alignment faults on ARMv6+, at least occur with axe(4) and athn(4) drivers. For ARMv6+, unaligned access is enabled by default. However, it cannot be used for non-cacheable memory, which is used as DMA buffers. This results in alignment faults above. A real fix is to use cacheable memory as DMA buffers. However, it breaks some drivers, awge(4) and vchiq(4) at least. Until we figure out problems and fix them, we choose a fail-safe workaround here; forbid unaligned memory access for whole kernel. Affects on performance is negligibly small as far as we can see. XXX pullup netbsd-9 - PR kern/54486 Revert workaround introduced in rev 1.94: http://cvsweb.netbsd.org/bsdweb.cgi/src/sys/dev/usb/if_axe.c#rev1.94 This is a problem specific to ARMv6+, and addressed by arch/arm/conf/Makefile.arm rev 1.50: http://cvsweb.netbsd.org/bsdweb.cgi/src/sys/arch/arm/conf/Makefile.arm#rev1.50 XXX pullup netbsd-9 To generate a diff of this commit: cvs rdiff -u -r1.49 -r1.49.4.1 src/sys/arch/arm/conf/Makefile.arm cvs rdiff -u -r1.102.2.1 -r1.102.2.2 src/sys/dev/usb/if_axe.c Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files.
Modified files: Index: src/sys/arch/arm/conf/Makefile.arm diff -u src/sys/arch/arm/conf/Makefile.arm:1.49 src/sys/arch/arm/conf/Makefile.arm:1.49.4.1 --- src/sys/arch/arm/conf/Makefile.arm:1.49 Sat Sep 22 12:24:01 2018 +++ src/sys/arch/arm/conf/Makefile.arm Sun Sep 1 14:03:02 2019 @@ -1,4 +1,4 @@ -# $NetBSD: Makefile.arm,v 1.49 2018/09/22 12:24:01 rin Exp $ +# $NetBSD: Makefile.arm,v 1.49.4.1 2019/09/01 14:03:02 martin Exp $ # Makefile for NetBSD # @@ -53,6 +53,26 @@ CPPFLAGS.cpufunc_asm_armv6.S+= -mcpu=arm CPPFLAGS.cpufunc_asm_arm11.S+= -mcpu=arm1136j-s CPPFLAGS.cpufunc_asm_xscale.S+= -mcpu=xscale +.if !empty(MACHINE_ARCH:Mearmv6*) || !empty(MACHINE_ARCH:Mearmv7*) +# XXX +# +# Workaround for alignment faults on ARMv6+, at least occur with +# axe(4) and athn(4) drivers. +# +# For ARMv6+, unaligned access is enabled by default. However, it +# cannot be used for non-cacheable memory, which is used as DMA +# buffers. This results in alignment faults above. A real fix is +# to use cacheable memory as DMA buffers. However, it breaks some +# drivers, awge(4) and vchiq(4) at least. +# +# Until we figure out problems and fix them, we choose a fail-safe +# workaround here; forbid unaligned memory access for whole kernel. +# Affects on performance is negligibly small as far as we can see. +# +# See PR kern/54486 for more details. +CFLAGS+= -mno-unaligned-access +.endif + ## ## (3) libkern and compat ## Index: src/sys/dev/usb/if_axe.c diff -u src/sys/dev/usb/if_axe.c:1.102.2.1 src/sys/dev/usb/if_axe.c:1.102.2.2 --- src/sys/dev/usb/if_axe.c:1.102.2.1 Sun Sep 1 13:00:36 2019 +++ src/sys/dev/usb/if_axe.c Sun Sep 1 14:03:02 2019 @@ -1,4 +1,4 @@ -/* $NetBSD: if_axe.c,v 1.102.2.1 2019/09/01 13:00:36 martin Exp $ */ +/* $NetBSD: if_axe.c,v 1.102.2.2 2019/09/01 14:03:02 martin Exp $ */ /* $OpenBSD: if_axe.c,v 1.137 2016/04/13 11:03:37 mpi Exp $ */ /* @@ -87,7 +87,7 @@ */ #include <sys/cdefs.h> -__KERNEL_RCSID(0, "$NetBSD: if_axe.c,v 1.102.2.1 2019/09/01 13:00:36 martin Exp $"); +__KERNEL_RCSID(0, "$NetBSD: if_axe.c,v 1.102.2.2 2019/09/01 14:03:02 martin Exp $"); #ifdef _KERNEL_OPT #include "opt_usb.h" @@ -1038,18 +1038,7 @@ axe_rx_loop(struct usbnet * un, struct u break; } -#if !defined(__NO_STRICT_ALIGNMENT) && __GNUC_PREREQ__(6, 1) - /* - * XXX hdr is 2-byte aligned in buf, not 4-byte. - * For some architectures, __builtin_memcpy() of - * GCC 6 attempts to copy sizeof(hdr) = 4 bytes - * at onece, which results in alignment error. - */ - hdr.len = *(uint16_t *)buf; - hdr.ilen = *(uint16_t *)(buf + sizeof(uint16_t)); -#else memcpy(&hdr, buf, sizeof(hdr)); -#endif DPRINTFN(20, "total_len %#jx len %jx ilen %#jx", total_len,