powerpc: Add denormalisation exception handling for POWER6/7
On POWER6 and POWER7 if the input operand to an instruction is a
denormalised single precision binary floating point value 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 <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
index 4c25319..5f73ce6 100644
--- a/arch/powerpc/include/asm/ppc-opcode.h
+++ b/arch/powerpc/include/asm/ppc-opcode.h
@@ -126,6 +126,7 @@
#define PPC_INST_TLBIVAX 0x7c000624
#define PPC_INST_TLBSRX_DOT 0x7c0006a5
#define PPC_INST_XXLOR 0xf0000510
+#define PPC_INST_XVCPSGNDP 0xf0000780
#define PPC_INST_NAP 0x4c000364
#define PPC_INST_SLEEP 0x4c0003a4
@@ -277,6 +278,8 @@
VSX_XX1((s), a, b))
#define XXLOR(t, a, b) stringify_in_c(.long PPC_INST_XXLOR | \
VSX_XX3((t), a, b))
+#define XVCPSGNDP(t, a, b) stringify_in_c(.long (PPC_INST_XVCPSGNDP | \
+ VSX_XX3((t), (a), (b))))
#define PPC_NAP stringify_in_c(.long PPC_INST_NAP)
#define PPC_SLEEP stringify_in_c(.long PPC_INST_SLEEP)