Fix the VFP handling on the Feroceon CPU

This CPU generates synchronous VFP exceptions in a non-standard way -
the FPEXC.EX bit set but without the FPSCR.IXE bit being set like in the
VFP subarchitecture 1 or just the FPEXC.DEX bit like in VFP
subarchitecture 2. The main problem is that the faulty instruction
(which needs to be emulated in software) will be restarted several times
(normally until a context switch disables the VFP). This patch ensures
that the VFP exception is treated as synchronous.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Nicolas Pitre <nico@cam.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
index 01599c4ef726..2d7423af1197 100644
--- a/arch/arm/vfp/vfpmodule.c
+++ b/arch/arm/vfp/vfpmodule.c
@@ -253,12 +253,14 @@ void VFP_bounce(u32 trigger, u32 fpexc, struct pt_regs *regs)
         }
 
         if (fpexc & FPEXC_EX) {
+#ifndef CONFIG_CPU_FEROCEON
                 /*
                  * Asynchronous exception. The instruction is read from FPINST
                  * and the interrupted instruction has to be restarted.
                  */
                 trigger = fmrx(FPINST);
                 regs->ARM_pc -= 4;
+#endif
         } else if (!(fpexc & FPEXC_DEX)) {
                 /*
                  * Illegal combination of bits. It can be caused by an