#ifndef MPOA_CACHES_H
#define MPOA_CACHES_H

#include <linux/netdevice.h>
#include <linux/types.h>
#include <linux/atm.h>
#include <linux/atmdev.h>
#include <linux/atmmpc.h>

struct mpoa_client;

void atm_mpoa_init_cache(struct mpoa_client *mpc);

typedef struct in_cache_entry {
	struct in_cache_entry *next;
	struct in_cache_entry *prev;
	struct timeval  tv;
	struct timeval  reply_wait;
	struct timeval  hold_down;
	uint32_t  packets_fwded;
	uint16_t  entry_state;
	uint32_t retry_time;
	uint32_t refresh_time;
	uint32_t count;
	struct   atm_vcc *shortcut;
	uint8_t  MPS_ctrl_ATM_addr[ATM_ESA_LEN];
	struct   in_ctrl_info ctrl_info;
	atomic_t use;
} in_cache_entry;

struct in_cache_ops{
	in_cache_entry *(*add_entry)(__be32 dst_ip,
				      struct mpoa_client *client);
	in_cache_entry *(*get)(__be32 dst_ip, struct mpoa_client *client);
	in_cache_entry *(*get_with_mask)(__be32 dst_ip,
					 struct mpoa_client *client,
					 __be32 mask);
	in_cache_entry *(*get_by_vcc)(struct atm_vcc *vcc,
				      struct mpoa_client *client);
	void            (*put)(in_cache_entry *entry);
	void            (*remove_entry)(in_cache_entry *delEntry,
					struct mpoa_client *client );
	int             (*cache_hit)(in_cache_entry *entry,
				     struct mpoa_client *client);
	void            (*clear_count)(struct mpoa_client *client);
	void            (*check_resolving)(struct mpoa_client *client);
	void            (*refresh)(struct mpoa_client *client);
	void            (*destroy_cache)(struct mpoa_client *mpc);
};

typedef struct eg_cache_entry{
	struct               eg_cache_entry *next;
	struct               eg_cache_entry *prev;
	struct               timeval  tv;
	uint8_t              MPS_ctrl_ATM_addr[ATM_ESA_LEN];
	struct atm_vcc       *shortcut;
	uint32_t             packets_rcvd;
	uint16_t             entry_state;
	__be32             latest_ip_addr;    /* The src IP address of the last packet */
	struct eg_ctrl_info  ctrl_info;
	atomic_t             use;
} eg_cache_entry;

struct eg_cache_ops{
	eg_cache_entry *(*add_entry)(struct k_message *msg, struct mpoa_client *client);
	eg_cache_entry *(*get_by_cache_id)(__be32 cache_id, struct mpoa_client *client);
	eg_cache_entry *(*get_by_tag)(__be32 cache_id, struct mpoa_client *client);
	eg_cache_entry *(*get_by_vcc)(struct atm_vcc *vcc, struct mpoa_client *client);
	eg_cache_entry *(*get_by_src_ip)(__be32 ipaddr, struct mpoa_client *client);
	void            (*put)(eg_cache_entry *entry);
	void            (*remove_entry)(eg_cache_entry *entry, struct mpoa_client *client);
	void            (*update)(eg_cache_entry *entry, uint16_t holding_time);
	void            (*clear_expired)(struct mpoa_client *client);
	void            (*destroy_cache)(struct mpoa_client *mpc);
};


/* Ingress cache entry states */

#define INGRESS_REFRESHING 3
#define INGRESS_RESOLVED   2
#define INGRESS_RESOLVING  1
#define INGRESS_INVALID    0

/* VCC states */

#define OPEN   1
#define CLOSED 0

/* Egress cache entry states */

#define EGRESS_RESOLVED 2
#define EGRESS_PURGE    1
#define EGRESS_INVALID  0

#endif
p;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>net</a>/<a href='/cgit.cgi/linux/net-next.git/commit/net/ipv6?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>ipv6</a>/<a href='/cgit.cgi/linux/net-next.git/commit/net/ipv6/exthdrs.c?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>exthdrs.c</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/net/ipv6/exthdrs.c?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>39cb2c9a316e77f6dfba96c543e55b6672d5a37e</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/ipv6/exthdrs.c?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/net/ipv6/exthdrs.c?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>net/ipv6/exthdrs.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/ipv6/exthdrs.c?h=nds-private-remove&amp;id=2c5d9555d6d937966d79d4c6529a5f7b9206e405'>2c5d9555d6d937966d79d4c6529a5f7b9206e405</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/ipv6/exthdrs.c?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 'net/ipv6/exthdrs.c')</div><table summary='diffstat' class='diffstat'>