On Jul 11, 2011, at 12:52 AM, Michael Neuling wrote: > On POWER6 and POWER7 if the input operand to an instruction is a > denormalised single precision binary floating we can take a > denormalisation exception where it's expected that the hypervisor (HV=1) > will fix up the inputs before the instruction is run. > > This adds code to handle this denormalisation exception for POWER6 and > POWER7. > > It also add a CONFIG_PPC_DENORMALISATION option and sets it in > pseries/ppc64_defconfig. > > This is useful on bare metal systems only. Based on patch from Milton > Miller. > > Signed-off-by: Michael Neuling <mi...@neuling.org> > > --- > arch/powerpc/Kconfig | 7 + > arch/powerpc/configs/ppc64_defconfig | 1 > arch/powerpc/configs/pseries_defconfig | 1 > arch/powerpc/include/asm/ppc-opcode.h | 2 > arch/powerpc/include/asm/reg.h | 1 > arch/powerpc/kernel/exceptions-64s.S | 125 > +++++++++++++++++++++++++++++++++ > 6 files changed, 137 insertions(+) > > Index: linux-ozlabs/arch/powerpc/Kconfig > =================================================================== > --- linux-ozlabs.orig/arch/powerpc/Kconfig > +++ linux-ozlabs/arch/powerpc/Kconfig > @@ -556,6 +556,13 @@ config SCHED_SMT > when dealing with POWER5 cpus at a cost of slightly increased > overhead in some places. If unsure say N here. > > +config PPC_DENORMALISATION > + bool "PowerPC denormalisation exception handling"
Should this at least depend on PPC_BOOK3S_64 ? > + default "n" > + ---help--- > + Add support for handling denormalisation of single precision > + values. Useful for bare metal only. If unsure say Y here. > + > config CMDLINE_BOOL > bool "Default bootloader kernel arguments" > > - k _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
