From 83bee792d7cb20d250be57e99d97f8cc83d9b4d5 Mon Sep 17 00:00:00 2001
From: Jayachandran C <jchandra@broadcom.com>
Date: Mon, 10 Jun 2013 06:30:01 +0000
Subject: [PATCH] MIPS: Allow kernel to use coprocessor 2
Kernel threads should be able to use COP2 if the platform needs it.
Do not call die_if_kernel() for a coprocessor unusable exception if
the exception due to COP2 usage. Instead, the default notifier for
COP2 exceptions is updated to call die_if_kernel.
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Cc: linux-mips@linux-mips.org
Cc: ddaney.cavm@gmail.com
Patchwork: https://patchwork.linux-mips.org/patch/5415/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
arch/mips/kernel/traps.c | 15 +++++----------
1 file changed, 5 insertions(+), 10 deletions(-)
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index beba1e616b6e..142d2bede024 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -1056,15 +1056,9 @@ static int default_cu2_call(struct notifier_block *nfb, unsigned long action,
{
struct pt_regs *regs = data;
- switch (action) {
- default:
- die_if_kernel("Unhandled kernel unaligned access or invalid "
+ die_if_kernel("COP2: Unhandled kernel unaligned access or invalid "
"instruction", regs);
- /* Fall through */
-
- case CU2_EXCEPTION:
- force_sig(SIGILL, current);
- }
+ force_sig(SIGILL, current);
return NOTIFY_OK;
}
@@ -1080,10 +1074,11 @@ asmlinkage void do_cpu(struct pt_regs *regs)
unsigned long __maybe_unused flags;
prev_state = exception_enter();
- die_if_kernel("do_cpu invoked from kernel context!", regs);
-
cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
+ if (cpid != 2)
+ die_if_kernel("do_cpu invoked from kernel context!", regs);
+
switch (cpid) {
case 0:
epc = (unsigned int __user *)exception_epc(regs);