MIPS: Allow kernel to use coprocessor 2 (83bee792) · Commits · 戴 / test

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

+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);

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