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Commit 83bee792 authored by Jayachandran C's avatar Jayachandran C Committed by Ralf Baechle
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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: default avatarJayachandran 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: default avatarRalf Baechle <ralf@linux-mips.org>
parent 2c952e06

arch/mips/kernel/traps.c

+5 −10
Original line number Diff line number Diff line
@@ -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);

	}



	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);