#ifndef _ISP1760_HCD_H_
#define _ISP1760_HCD_H_

#include <linux/spinlock.h>

struct isp1760_qh;
struct isp1760_qtd;
struct resource;
struct usb_hcd;

/*
 * 60kb divided in:
 * - 32 blocks @ 256  bytes
 * - 20 blocks @ 1024 bytes
 * -  4 blocks @ 8192 bytes
 */

#define BLOCK_1_NUM 32
#define BLOCK_2_NUM 20
#define BLOCK_3_NUM 4

#define BLOCK_1_SIZE 256
#define BLOCK_2_SIZE 1024
#define BLOCK_3_SIZE 8192
#define BLOCKS (BLOCK_1_NUM + BLOCK_2_NUM + BLOCK_3_NUM)
#define MAX_PAYLOAD_SIZE BLOCK_3_SIZE
#define PAYLOAD_AREA_SIZE 0xf000

struct isp1760_slotinfo {
	struct isp1760_qh *qh;
	struct isp1760_qtd *qtd;
	unsigned long timestamp;
};

/* chip memory management */
struct isp1760_memory_chunk {
	unsigned int start;
	unsigned int size;
	unsigned int free;
};

enum isp1760_queue_head_types {
	QH_CONTROL,
	QH_BULK,
	QH_INTERRUPT,
	QH_END
};

struct isp1760_hcd {
#ifdef CONFIG_USB_ISP1760_HCD
	struct usb_hcd		*hcd;

	u32 hcs_params;
	spinlock_t		lock;
	struct isp1760_slotinfo	atl_slots[32];
	int			atl_done_map;
	struct isp1760_slotinfo	int_slots[32];
	int			int_done_map;
	struct isp1760_memory_chunk memory_pool[BLOCKS];
	struct list_head	qh_list[QH_END];

	/* periodic schedule support */
#define	DEFAULT_I_TDPS		1024
	unsigned		periodic_size;
	unsigned		i_thresh;
	unsigned long		reset_done;
	unsigned long		next_statechange;
#endif
};

#ifdef CONFIG_USB_ISP1760_HCD
int isp1760_hcd_register(struct isp1760_hcd *priv, void __iomem *regs,
			 struct resource *mem, int irq, unsigned long irqflags,
			 struct device *dev);
void isp1760_hcd_unregister(struct isp1760_hcd *priv);

int isp1760_init_kmem_once(void);
void isp1760_deinit_kmem_cache(void);
#else
static inline int isp1760_hcd_register(struct isp1760_hcd *priv,
				       void __iomem *regs, struct resource *mem,
				       int irq, unsigned long irqflags,
				       struct device *dev)
{
	return 0;
}

static inline void isp1760_hcd_unregister(struct isp1760_hcd *priv)
{
}

static inline int isp1760_init_kmem_once(void)
{
	return 0;
}

static inline void isp1760_deinit_kmem_cache(void)
{
}
#endif

#endif /* _ISP1760_HCD_H_ */
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<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/commit/?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/net?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>net</a>/<a href='/cgit.cgi/linux/net-next.git/commit/net/ipv6?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>ipv6</a>/<a href='/cgit.cgi/linux/net-next.git/commit/net/ipv6/ip6mr.c?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>ip6mr.c</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><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/ip6mr.c?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>39cb2c9a316e77f6dfba96c543e55b6672d5a37e</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/ipv6/ip6mr.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/?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>98fe974ee4e20121253de7f61fc8d01bdb3821c1</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/ipv6/ip6mr.c?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>net/ipv6/ip6mr.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/ipv6/ip6mr.c?id=2c5d9555d6d937966d79d4c6529a5f7b9206e405'>2c5d9555d6d937966d79d4c6529a5f7b9206e405</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/ipv6/ip6mr.c?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/?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>Diffstat</a> (limited to 'net/ipv6/ip6mr.c')</div><table summary='diffstat' class='diffstat'>