user/sven/linux.git/include/linux/reservation.h, branch v5.3.2

dma-fence/reservation: Markup rcu protected access for DEBUG_MUTEXES

2019-06-12T14:27:44Z

Mark the access to reservation_object.fence as being protected to silence sparse. Signed-off-by: Chris Wilson Reviewed-by: Christian König Link: https://patchwork.freedesktop.org/patch/msgid/20190612132830.31221-1-chris@chris-wilson.co.uk

dma-buf: clarify locking documentation for reservation_object_get_excl

2019-02-27T22:51:51Z

The documentation was misleading, as for a lot of use-cases holding the RCU read side lock is sufficient. Signed-off-by: Lucas Stach Reviewed-by: Christian König Link: https://patchwork.freedesktop.org/patch/msgid/20180111165302.25556-2-l.stach@pengutronix.de

dma-buf: test shared slot allocation when mutex debugging is active

2018-10-25T11:45:23Z

Set shared_max to the number of shared fences right before we release the lock. This way every attempt to add a shared fence without previously reserving a slot will cause an error. Signed-off-by: Christian König Reviewed-by: Huang Rui Acked-by: Junwei Zhang Link: https://patchwork.kernel.org/patch/10626147/

dma-buf: allow reserving more than one shared fence slot

2018-10-25T11:45:07Z

Let's support simultaneous submissions to multiple engines. Signed-off-by: Christian König Reviewed-by: Michel Dänzer Reviewed-by: Junwei Zhang Reviewed-by: Huang Rui Link: https://patchwork.kernel.org/patch/10626149/

dma-buf: remove shared fence staging in reservation object

2018-10-25T11:41:16Z

No need for that any more. Just replace the list when there isn't enough room any more for the additional fence. Signed-off-by: Christian König Reviewed-by: Junwei Zhang Reviewed-by: Huang Rui Link: https://patchwork.kernel.org/patch/10626143/

dma-buf: add reservation_object_lock_interruptible()

2017-11-13T19:50:49Z

That's the only wrapper function missing and necessary to cleanup TTM. Reviewed-and-Tested-by: Michel Dänzer Signed-off-by: Christian König Signed-off-by: Alex Deucher Link: https://patchwork.freedesktop.org/patch/msgid/20171109085909.1653-3-christian.koenig@amd.com

dma-buf: add reservation_object_copy_fences (v2)

2017-08-14T17:00:49Z

Allows us to copy all the fences in a reservation object to another one. v2: handle NULL src_list Signed-off-by: Christian König Reviewed-by: Alex Deucher Signed-off-by: Alex Deucher Link: https://patchwork.freedesktop.org/patch/msgid/1502384509-10465-2-git-send-email-alexander.deucher@amd.com

dma-buf/reservation: Wrap ww_mutex_trylock

2017-02-26T21:43:44Z

In a similar fashion to reservation_object_lock() and reservation_object_unlock(), ww_mutex_trylock is also useful and so is worth wrapping for consistency. Signed-off-by: Chris Wilson Cc: Sumit Semwal Cc: Joonas Lahtinen Cc: Daniel Vetter [danvet: Add __must_check Joonas wants.] Reviewed-by: Joonas Lahtinen Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/20170221093000.22802-1-chris@chris-wilson.co.uk

dma-buf: Provide wrappers for reservation's lock

2016-12-12T06:54:43Z

Joonas complained that writing ww_mutex_lock(&resv->lock, ctx) was too intrusive compared to reservation_object_lock(resv, ctx); Signed-off-by: Chris Wilson Cc: Sumit Semwal Cc: Joonas Lahtinen Reviewed-by: Alex Deucher Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/20161115154642.31850-1-chris@chris-wilson.co.uk

dma-buf: Use fence_get_rcu_safe() for retrieving the exclusive fence

2016-11-15T07:30:02Z

The current code is subject to a race where we may try to acquire a reference on a stale fence: [13703.335118] WARNING: CPU: 1 PID: 14975 at ./include/linux/kref.h:46 i915_gem_object_wait+0x1a3/0x1c0 [13703.335184] Modules linked in: [13703.335202] CPU: 1 PID: 14975 Comm: gem_concurrent_ Not tainted 4.9.0-rc4+ #26 [13703.335216] Hardware name: / , BIOS PYBSWCEL.86A.0027.2015.0507.1758 05/07/2015 [13703.335233] ffffc90002f5bcc8 ffffffff812807de 0000000000000000 0000000000000000 [13703.335257] ffffc90002f5bd08 ffffffff81073811 0000002e80000000 ffff88026bf7c780 [13703.335279] 7fffffffffffffff 0000000000000001 ffff88027045a550 ffff88026bf7c780 [13703.335301] Call Trace: [13703.335316] [] dump_stack+0x4d/0x6f [13703.335331] [] __warn+0xc1/0xe0 [13703.335343] [] warn_slowpath_null+0x18/0x20 [13703.335355] [] i915_gem_object_wait+0x1a3/0x1c0 [13703.335367] [] i915_gem_set_domain_ioctl+0xcc/0x330 [13703.335386] [] drm_ioctl+0x1cb/0x410 [13703.335400] [] ? i915_gem_obj_prepare_shmem_write+0x1d0/0x1d0 [13703.335416] [] ? drm_ioctl+0x2bb/0x410 [13703.335429] [] do_vfs_ioctl+0x8f/0x5c0 [13703.335442] [] SyS_ioctl+0x3c/0x70 [13703.335456] [] entry_SYSCALL_64_fastpath+0x17/0x98 [13703.335558] ---[ end trace fd24176416ba6981 ]--- [13703.382778] general protection fault: 0000 [#1] SMP [13703.382802] Modules linked in: [13703.382816] CPU: 1 PID: 14967 Comm: gem_concurrent_ Tainted: G W 4.9.0-rc4+ #26 [13703.382828] Hardware name: / , BIOS PYBSWCEL.86A.0027.2015.0507.1758 05/07/2015 [13703.382841] task: ffff880275458000 task.stack: ffffc90002f18000 [13703.382849] RIP: 0010:[] [] i915_gem_request_retire+0x2b4/0x320 [13703.382870] RSP: 0018:ffffc90002f1bbc8 EFLAGS: 00010293 [13703.382878] RAX: dead000000000200 RBX: ffff88026bf7dce8 RCX: dead000000000100 [13703.382887] RDX: dead000000000100 RSI: ffff88026bf7c930 RDI: ffff88026bf7dd00 [13703.382897] RBP: ffffc90002f1bbf8 R08: 00000000ffffffff R09: ffff88026b89a000 [13703.382905] R10: 0000000000000001 R11: ffff88026bbe8fe0 R12: ffff88026bf7c000 [13703.382913] R13: ffff880275af8000 R14: ffff88026bf7c180 R15: dead000000000200 [13703.382922] FS: 00007f89e787d740(0000) GS:ffff88027fd00000(0000) knlGS:0000000000000000 [13703.382934] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [13703.382942] CR2: 00007f9053d2e000 CR3: 000000026d414000 CR4: 00000000001006e0 [13703.382951] Stack: [13703.382958] ffff880275413000 ffffc90002f1bde8 ffff880275af8000 ffff880274e8a600 [13703.382976] ffff880276a06000 ffffc90002f1bde8 ffffc90002f1bc38 ffffffff813b48c5 [13703.382995] ffffc90002f1bc00 ffffc90002f1bde8 ffff88026972a440 0000000000000000 [13703.383021] Call Trace: [13703.383032] [] i915_gem_request_alloc+0xa5/0x350 [13703.383043] [] i915_gem_do_execbuffer.isra.41+0x7b3/0x18b0 [13703.383055] [] ? i915_gem_object_get_sg+0x25c/0x2b0 [13703.383065] [] ? i915_gem_object_get_page+0x1d/0x50 [13703.383076] [] ? i915_gem_pwrite_ioctl+0x66c/0x6d0 [13703.383086] [] i915_gem_execbuffer2+0x95/0x1e0 [13703.383096] [] drm_ioctl+0x1cb/0x410 [13703.383105] [] ? i915_gem_execbuffer+0x2d0/0x2d0 [13703.383117] [] ? hrtimer_start_range_ns+0x1a0/0x310 [13703.383128] [] do_vfs_ioctl+0x8f/0x5c0 [13703.383140] [] ? SyS_timer_settime+0x118/0x1a0 [13703.383150] [] SyS_ioctl+0x3c/0x70 [13703.383162] [] entry_SYSCALL_64_fastpath+0x17/0x98 [13703.383172] Code: 49 39 c6 48 8d 70 e8 48 8d 5f e8 75 16 eb 47 48 8d 43 18 48 8b 53 18 48 89 de 49 39 c6 48 8d 5a e8 74 33 48 8b 56 08 48 8b 46 10 <48> 89 42 08 48 89 10 f6 46 38 01 48 89 4e 08 4c 89 7e 10 74 cf [13703.383557] RIP [] i915_gem_request_retire+0x2b4/0x320 [13703.383570] RSP [13703.383586] ---[ end trace fd24176416ba6982 ]--- This is fixed by using the kref_get_unless_zero() as a full memory barrier to validate the fence is still the current exclusive fence before returning it back to the caller. (Note the fix only requires using dma_fence_get_rcu() and correct handling, but we may as well use the helper rather than inline equivalent code.) Note: Issue can only be hit with the i915 driver. Signed-off-by: Chris Wilson Cc: Sumit Semwal . Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/20161114115540.31155-1-chris@chris-wilson.co.uk