In message [ref] you wrote
:

On Jul 11, 2011, at 12:52 AM, Michael Neuling wrote:

quoted

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=3D1)

quoted

will fix up the inputs before the instruction is run.
=20
This adds code to handle this denormalisation exception for POWER6 and
POWER7.
=20
It also add a CONFIG_PPC_DENORMALISATION option and sets it in
pseries/ppc64_defconfig.=20
=20
This is useful on bare metal systems only.  Based on patch from Milton
Miller.
=20
Signed-off-by: Michael Neuling <redacted>
=20
---
arch/powerpc/Kconfig                   |    7 +
arch/powerpc/configs/ppc64_defconfig   |    1=20
arch/powerpc/configs/pseries_defconfig |    1=20
arch/powerpc/include/asm/ppc-opcode.h  |    2=20
arch/powerpc/include/asm/reg.h         |    1=20
arch/powerpc/kernel/exceptions-64s.S   |  125 =

+++++++++++++++++++++++++++++++++

quoted

6 files changed, 137 insertions(+)
=20
Index: linux-ozlabs/arch/powerpc/Kconfig
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D

quoted

--- 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.
=20
+config PPC_DENORMALISATION
+	bool "PowerPC denormalisation exception handling"

Should this at least depend on PPC_BOOK3S_64 ?

Yep, thanks!

Mikey