/*
 * linux/fs/befs/endian.h
 *
 * Copyright (C) 2001 Will Dyson <will_dyson@pobox.com>
 *
 * Partially based on similar funtions in the sysv driver.
 */

#ifndef LINUX_BEFS_ENDIAN
#define LINUX_BEFS_ENDIAN

#include <asm/byteorder.h>

static inline u64
fs64_to_cpu(const struct super_block *sb, fs64 n)
{
	if (BEFS_SB(sb)->byte_order == BEFS_BYTESEX_LE)
		return le64_to_cpu((__force __le64)n);
	else
		return be64_to_cpu((__force __be64)n);
}

static inline fs64
cpu_to_fs64(const struct super_block *sb, u64 n)
{
	if (BEFS_SB(sb)->byte_order == BEFS_BYTESEX_LE)
		return (__force fs64)cpu_to_le64(n);
	else
		return (__force fs64)cpu_to_be64(n);
}

static inline u32
fs32_to_cpu(const struct super_block *sb, fs32 n)
{
	if (BEFS_SB(sb)->byte_order == BEFS_BYTESEX_LE)
		return le32_to_cpu((__force __le32)n);
	else
		return be32_to_cpu((__force __be32)n);
}

static inline fs32
cpu_to_fs32(const struct super_block *sb, u32 n)
{
	if (BEFS_SB(sb)->byte_order == BEFS_BYTESEX_LE)
		return (__force fs32)cpu_to_le32(n);
	else
		return (__force fs32)cpu_to_be32(n);
}

static inline u16
fs16_to_cpu(const struct super_block *sb, fs16 n)
{
	if (BEFS_SB(sb)->byte_order == BEFS_BYTESEX_LE)
		return le16_to_cpu((__force __le16)n);
	else
		return be16_to_cpu((__force __be16)n);
}

static inline fs16
cpu_to_fs16(const struct super_block *sb, u16 n)
{
	if (BEFS_SB(sb)->byte_order == BEFS_BYTESEX_LE)
		return (__force fs16)cpu_to_le16(n);
	else
		return (__force fs16)cpu_to_be16(n);
}

/* Composite types below here */

static inline befs_block_run
fsrun_to_cpu(const struct super_block *sb, befs_disk_block_run n)
{
	befs_block_run run;

	if (BEFS_SB(sb)->byte_order == BEFS_BYTESEX_LE) {
		run.allocation_group = le32_to_cpu((__force __le32)n.allocation_group);
		run.start = le16_to_cpu((__force __le16)n.start);
		run.len = le16_to_cpu((__force __le16)n.len);
	} else {
		run.allocation_group = be32_to_cpu((__force __be32)n.allocation_group);
		run.start = be16_to_cpu((__force __be16)n.start);
		run.len = be16_to_cpu((__force __be16)n.len);
	}
	return run;
}

static inline befs_disk_block_run
cpu_to_fsrun(const struct super_block *sb, befs_block_run n)
{
	befs_disk_block_run run;

	if (BEFS_SB(sb)->byte_order == BEFS_BYTESEX_LE) {
		run.allocation_group = cpu_to_le32(n.allocation_group);
		run.start = cpu_to_le16(n.start);
		run.len = cpu_to_le16(n.len);
	} else {
		run.allocation_group = cpu_to_be32(n.allocation_group);
		run.start = cpu_to_be16(n.start);
		run.len = cpu_to_be16(n.len);
	}
	return run;
}

static inline befs_data_stream
fsds_to_cpu(const struct super_block *sb, const befs_disk_data_stream *n)
{
	befs_data_stream data;
	int i;

	for (i = 0; i < BEFS_NUM_DIRECT_BLOCKS; ++i)
		data.direct[i] = fsrun_to_cpu(sb, n->direct[i]);

	data.max_direct_range = fs64_to_cpu(sb, n->max_direct_range);
	data.indirect = fsrun_to_cpu(sb, n->indirect);
	data.max_indirect_range = fs64_to_cpu(sb, n->max_indirect_range);
	data.double_indirect = fsrun_to_cpu(sb, n->double_indirect);
	data.max_double_indirect_range = fs64_to_cpu(sb,
						     n->
						     max_double_indirect_range);
	data.size = fs64_to_cpu(sb, n->size);

	return data;
}

#endif				//LINUX_BEFS_ENDIAN
>/<a href='/cgit.cgi/linux/net-next.git/commit/include/soc?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>soc</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include/soc/imx?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>imx</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include/soc/imx/cpuidle.h?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>cpuidle.h</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='h' value='nds-private-remove'/><input type='hidden' name='id' value='39cb2c9a316e77f6dfba96c543e55b6672d5a37e'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-29 13:50:06 -0800</td></tr>
<tr><th>committer</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-29 13:50:06 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/soc/imx/cpuidle.h?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>39cb2c9a316e77f6dfba96c543e55b6672d5a37e</a> (<a href='/cgit.cgi/linux/net-next.git/patch/include/soc/imx/cpuidle.h?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>98fe974ee4e20121253de7f61fc8d01bdb3821c1</a> /<a href='/cgit.cgi/linux/net-next.git/tree/include/soc/imx/cpuidle.h?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>include/soc/imx/cpuidle.h</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/soc/imx/cpuidle.h?h=nds-private-remove&amp;id=2c5d9555d6d937966d79d4c6529a5f7b9206e405'>2c5d9555d6d937966d79d4c6529a5f7b9206e405</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include/soc/imx/cpuidle.h?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e&amp;id2=2c5d9555d6d937966d79d4c6529a5f7b9206e405'>diff</a>)</td></tr></table>
<div class='commit-subject'>drm/i915: Check for NULL i915_vma in intel_unpin_fb_obj()</div><div class='commit-msg'>I've seen this trigger twice now, where the i915_gem_object_to_ggtt()
call in intel_unpin_fb_obj() returns NULL, resulting in an oops
immediately afterwards as the (inlined) call to i915_vma_unpin_fence()
tries to dereference it.

It seems to be some race condition where the object is going away at
shutdown time, since both times happened when shutting down the X
server.  The call chains were different:

 - VT ioctl(KDSETMODE, KD_TEXT):

    intel_cleanup_plane_fb+0x5b/0xa0 [i915]
    drm_atomic_helper_cleanup_planes+0x6f/0x90 [drm_kms_helper]
    intel_atomic_commit_tail+0x749/0xfe0 [i915]
    intel_atomic_commit+0x3cb/0x4f0 [i915]
    drm_atomic_commit+0x4b/0x50 [drm]
    restore_fbdev_mode+0x14c/0x2a0 [drm_kms_helper]
    drm_fb_helper_restore_fbdev_mode_unlocked+0x34/0x80 [drm_kms_helper]
    drm_fb_helper_set_par+0x2d/0x60 [drm_kms_helper]
    intel_fbdev_set_par+0x18/0x70 [i915]
    fb_set_var+0x236/0x460
    fbcon_blank+0x30f/0x350
    do_unblank_screen+0xd2/0x1a0
    vt_ioctl+0x507/0x12a0
    tty_ioctl+0x355/0xc30
    do_vfs_ioctl+0xa3/0x5e0
    SyS_ioctl+0x79/0x90
    entry_SYSCALL_64_fastpath+0x13/0x94

 - i915 unpin_work workqueue:

    intel_unpin_work_fn+0x58/0x140 [i915]
    process_one_work+0x1f1/0x480
    worker_thread+0x48/0x4d0
    kthread+0x101/0x140

and this patch purely papers over the issue by adding a NULL pointer
check and a WARN_ON_ONCE() to avoid the oops that would then generally
make the machine unresponsive.

Other callers of i915_gem_object_to_ggtt() seem to also check for the
returned pointer being NULL and warn about it, so this clearly has
happened before in other places.

[ Reported it originally to the i915 developers on Jan 8, applying the
  ugly workaround on my own now after triggering the problem for the
  second time with no feedback.

  This is likely to be the same bug reported as

     https://bugs.freedesktop.org/show_bug.cgi?id=98829
     https://bugs.freedesktop.org/show_bug.cgi?id=99134

  which has a patch for the underlying problem, but it hasn't gotten to
  me, so I'm applying the workaround. ]

Cc: Daniel Vetter &lt;daniel.vetter@intel.com&gt;
Cc: Jani Nikula &lt;jani.nikula@linux.intel.com&gt;
Cc: Ville Syrjälä &lt;ville.syrjala@linux.intel.com&gt;
Cc: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Tvrtko Ursulin &lt;tvrtko.ursulin@intel.com&gt;
Cc: Imre Deak &lt;imre.deak@intel.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>Diffstat</a> (limited to 'include/soc/imx/cpuidle.h')</div><table summary='diffstat' class='diffstat'>