[POWERPC] Add support for FP emulation for the e300c2 core

The e300c2 has no FPU.  Its MSR[FP] is grounded to zero.  If an attempt
is made to execute a floating point instruction (including floating-point
load, store, or move instructions), the e300c2 takes a floating-point
unavailable interrupt.

This patch adds support for FP emulation on the e300c2 by declaring a
new CPU_FTR_FP_TAKES_FPUNAVAIL, where FP unavail interrupts are
intercepted and redirected to the ProgramCheck exception path for
correct emulation handling.

(If we run out of CPU_FTR bits we could look to reclaim this bit by adding
support to test the cpu_user_features for PPC_FEATURE_HAS_FPU instead)

It adds a nop to the exception path for 32-bit processors with a FPU.

Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/arch/powerpc/kernel/cputable.c b/arch/powerpc/kernel/cputable.c
index 9d1614c3ce67..11bfbaf655b5 100644
--- a/arch/powerpc/kernel/cputable.c
+++ b/arch/powerpc/kernel/cputable.c
@@ -833,7 +833,7 @@ static struct cpu_spec cpu_specs[] = {
                 .pvr_mask               = 0x7fff0000,
                 .pvr_value              = 0x00840000,
                 .cpu_name               = "e300c2",
-                .cpu_features           = CPU_FTRS_E300,
+                .cpu_features           = CPU_FTRS_E300C2,
                 .cpu_user_features      = PPC_FEATURE_32 | PPC_FEATURE_HAS_MMU,
                 .icache_bsize           = 32,
                 .dcache_bsize           = 32,