/* Software floating-point emulation.
Definitions for IEEE Single Precision.
Copyright (C) 1997,1998,1999 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Richard Henderson (rth@cygnus.com),
Jakub Jelinek (jj@ultra.linux.cz),
David S. Miller (davem@redhat.com) and
Peter Maydell (pmaydell@chiark.greenend.org.uk).
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc.,
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#ifndef __MATH_EMU_SINGLE_H__
#define __MATH_EMU_SINGLE_H__
#if _FP_W_TYPE_SIZE < 32
#error "Here's a nickel kid. Go buy yourself a real computer."
#endif
#define _FP_FRACBITS_S 24
#define _FP_FRACXBITS_S (_FP_W_TYPE_SIZE - _FP_FRACBITS_S)
#define _FP_WFRACBITS_S (_FP_WORKBITS + _FP_FRACBITS_S)
#define _FP_WFRACXBITS_S (_FP_W_TYPE_SIZE - _FP_WFRACBITS_S)
#define _FP_EXPBITS_S 8
#define _FP_EXPBIAS_S 127
#define _FP_EXPMAX_S 255
#define _FP_QNANBIT_S ((_FP_W_TYPE)1 << (_FP_FRACBITS_S-2))
#define _FP_IMPLBIT_S ((_FP_W_TYPE)1 << (_FP_FRACBITS_S-1))
#define _FP_OVERFLOW_S ((_FP_W_TYPE)1 << (_FP_WFRACBITS_S))
/* The implementation of _FP_MUL_MEAT_S and _FP_DIV_MEAT_S should be
chosen by the target machine. */
union _FP_UNION_S
{
float flt;
struct {
#if __BYTE_ORDER == __BIG_ENDIAN
unsigned sign : 1;
unsigned exp : _FP_EXPBITS_S;
unsigned frac : _FP_FRACBITS_S - (_FP_IMPLBIT_S != 0);
#else
unsigned frac : _FP_FRACBITS_S - (_FP_IMPLBIT_S != 0);
unsigned exp : _FP_EXPBITS_S;
unsigned sign : 1;
#endif
} bits __attribute__((packed));
};
#define FP_DECL_S(X) _FP_DECL(1,X)
#define FP_UNPACK_RAW_S(X,val) _FP_UNPACK_RAW_1(S,X,val)
#define FP_UNPACK_RAW_SP(X,val) _FP_UNPACK_RAW_1_P(S,X,val)
#define FP_PACK_RAW_S(val,X) _FP_PACK_RAW_1(S,val,X)
#define FP_PACK_RAW_SP(val,X) \
do { \
if (!FP_INHIBIT_RESULTS) \
_FP_PACK_RAW_1_P(S,val,X); \
} while (0)
#define FP_UNPACK_S(X,val) \
do { \
_FP_UNPACK_RAW_1(S,X,val); \
_FP_UNPACK_CANONICAL(S,1,X); \
} while (0)
#define FP_UNPACK_SP(X,val) \
do { \
_FP_UNPACK_RAW_1_P(S,X,val); \
_FP_UNPACK_CANONICAL(S,1,X); \
} while (0)
#define FP_PACK_S(val,X) \
do { \
_FP_PACK_CANONICAL(S,1,X); \
_FP_PACK_RAW_1(S,val,X); \
} while (0)
#define FP_PACK_SP(val,X) \
do { \
_FP_PACK_CANONICAL(S,1,X); \
if (!FP_INHIBIT_RESULTS) \
_FP_PACK_RAW_1_P(S,val,X); \
} while (0)
#define FP_ISSIGNAN_S(X) _FP_ISSIGNAN(S,1,X)
#define FP_NEG_S(R,X) _FP_NEG(S,1,R,X)
#define FP_ADD_S(R,X,Y) _FP_ADD(S,1,R,X,Y)
#define FP_SUB_S(R,X,Y) _FP_SUB(S,1,R,X,Y)
#define FP_MUL_S(R,X,Y) _FP_MUL(S,1,R,X,Y)
#define FP_DIV_S(R,X,Y) _FP_DIV(S,1,R,X,Y)
#define FP_SQRT_S(R,X) _FP_SQRT(S,1,R,X)
#define _FP_SQRT_MEAT_S(R,S,T,X,Q) _FP_SQRT_MEAT_1(R,S,T,X,Q)
#define FP_CMP_S(r,X,Y,un) _FP_CMP(S,1,r,X,Y,un)
#define FP_CMP_EQ_S(r,X,Y) _FP_CMP_EQ(S,1,r,X,Y)
#define FP_TO_INT_S(r,X,rsz,rsg) _FP_TO_INT(S,1,r,X,rsz,rsg)
#define FP_TO_INT_ROUND_S(r,X,rsz,rsg) _FP_TO_INT_ROUND(S,1,r,X,rsz,rsg)
#define FP_FROM_INT_S(X,r,rs,rt) _FP_FROM_INT(S,1,X,r,rs,rt)
#define _FP_FRAC_HIGH_S(X) _FP_FRAC_HIGH_1(X)
#define _FP_FRAC_HIGH_RAW_S(X) _FP_FRAC_HIGH_1(X)
#endif /* __MATH_EMU_SINGLE_H__ */
drm/i915: Check for NULL i915_vma in intel_unpin_fb_obj()
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 <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>