diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/Kconfig | 19 | ||||
| -rw-r--r-- | arch/powerpc/Kconfig | 1 | ||||
| -rw-r--r-- | arch/x86/Kconfig | 1 |
3 files changed, 21 insertions, 0 deletions
diff --git a/arch/Kconfig b/arch/Kconfig index 6093c0be58b..b0fabfa864f 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -27,6 +27,25 @@ config KPROBES for kernel debugging, non-intrusive instrumentation and testing. If in doubt, say "N". +config HAVE_EFFICIENT_UNALIGNED_ACCESS + def_bool n + help + Some architectures are unable to perform unaligned accesses + without the use of get_unaligned/put_unaligned. Others are + unable to perform such accesses efficiently (e.g. trap on + unaligned access and require fixing it up in the exception + handler.) + + This symbol should be selected by an architecture if it can + perform unaligned accesses efficiently to allow different + code paths to be selected for these cases. Some network + drivers, for example, could opt to not fix up alignment + problems with received packets if doing so would not help + much. + + See Documentation/unaligned-memory-access.txt for more + information on the topic of unaligned memory accesses. + config KRETPROBES def_bool y depends on KPROBES && HAVE_KRETPROBES diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index a487671c282..de6b49cd6be 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -112,6 +112,7 @@ config PPC select HAVE_FTRACE select HAVE_IDE select HAVE_IOREMAP_PROT + select HAVE_EFFICIENT_UNALIGNED_ACCESS select HAVE_KPROBES select HAVE_ARCH_KGDB select HAVE_KRETPROBES diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index b2ddfcf0172..66f3ab05b18 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -28,6 +28,7 @@ config X86 select HAVE_FTRACE select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64) select HAVE_ARCH_KGDB if !X86_VOYAGER + select HAVE_EFFICIENT_UNALIGNED_ACCESS config ARCH_DEFCONFIG string |