powerpc/mm: Fix spurrious segfaults on radix with autonuma

When autonuma (Automatic NUMA balancing) marks a PTE inaccessible it
clears all the protection bits but leave the PTE valid.

With the Radix MMU, an attempt at executing from such a PTE will
take a fault with bit 35 of SRR1 set "SRR1_ISI_N_OR_G".

It is thus incorrect to treat all such faults as errors. We should
pass them to handle_mm_fault() for autonuma to deal with. The case
of pages that are really not executable is handled by the existing
test for VM_EXEC further down.

That leaves us with catching the kernel attempts at executing user
pages. We can catch that earlier, even before we do find_vma.

It is never valid on powerpc for the kernel to take an exec fault
to begin with. So fold that test with the existing test for the
kernel faulting on kernel addresses to bail out early.

Fixes: 1d18ad026844 ("powerpc/mm: Detect instruction fetch denied and report")
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

path: root/include/soc/imx/timer.h

/*
 * Copyright 2015 Linaro Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#ifndef __SOC_IMX_TIMER_H__
#define __SOC_IMX_TIMER_H__

enum imx_gpt_type {
	GPT_TYPE_IMX1,		/* i.MX1 */
	GPT_TYPE_IMX21,		/* i.MX21/27 */
	GPT_TYPE_IMX31,		/* i.MX31/35/25/37/51/6Q */
	GPT_TYPE_IMX6DL,	/* i.MX6DL/SX/SL */
};

/*
 * This is a stop-gap solution for clock drivers like imx1/imx21 which call
 * mxc_timer_init() to initialize timer for non-DT boot.  It can be removed
 * when these legacy non-DT support is converted or dropped.
 */
void mxc_timer_init(unsigned long pbase, int irq, enum imx_gpt_type type);

#endif  /* __SOC_IMX_TIMER_H__ */