delta/linux.git/include/linux/reservation.h, branch proc-cmdline

dma-buf: add reservation_object_lock_interruptible()

2017-11-13T19:50:49+00:00

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)

2017-08-14T17:00:49+00:00

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

2017-02-26T21:43:44+00:00

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

2016-12-12T06:54:43+00:00

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

2016-11-15T07:30:02+00:00

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

dma-buf: Rename struct fence to dma_fence

2016-10-25T12:40:39+00:00

I plan to usurp the short name of struct fence for a core kernel struct,
and so I need to rename the specialised fence/timeline for DMA
operations to make room.

A consensus was reached in
https://lists.freedesktop.org/archives/dri-devel/2016-July/113083.html
that making clear this fence applies to DMA operations was a good thing.
Since then the patch has grown a bit as usage increases, so hopefully it
remains a good thing!

(v2...: rebase, rerun spatch)
v3: Compile on msm, spotted a manual fixup that I broke.
v4: Try again for msm, sorry Daniel

coccinelle script:
@@

@@
- struct fence
+ struct dma_fence
@@

@@
- struct fence_ops
+ struct dma_fence_ops
@@

@@
- struct fence_cb
+ struct dma_fence_cb
@@

@@
- struct fence_array
+ struct dma_fence_array
@@

@@
- enum fence_flag_bits
+ enum dma_fence_flag_bits
@@

@@
(
- fence_init
+ dma_fence_init
|
- fence_release
+ dma_fence_release
|
- fence_free
+ dma_fence_free
|
- fence_get
+ dma_fence_get
|
- fence_get_rcu
+ dma_fence_get_rcu
|
- fence_put
+ dma_fence_put
|
- fence_signal
+ dma_fence_signal
|
- fence_signal_locked
+ dma_fence_signal_locked
|
- fence_default_wait
+ dma_fence_default_wait
|
- fence_add_callback
+ dma_fence_add_callback
|
- fence_remove_callback
+ dma_fence_remove_callback
|
- fence_enable_sw_signaling
+ dma_fence_enable_sw_signaling
|
- fence_is_signaled_locked
+ dma_fence_is_signaled_locked
|
- fence_is_signaled
+ dma_fence_is_signaled
|
- fence_is_later
+ dma_fence_is_later
|
- fence_later
+ dma_fence_later
|
- fence_wait_timeout
+ dma_fence_wait_timeout
|
- fence_wait_any_timeout
+ dma_fence_wait_any_timeout
|
- fence_wait
+ dma_fence_wait
|
- fence_context_alloc
+ dma_fence_context_alloc
|
- fence_array_create
+ dma_fence_array_create
|
- to_fence_array
+ to_dma_fence_array
|
- fence_is_array
+ dma_fence_is_array
|
- trace_fence_emit
+ trace_dma_fence_emit
|
- FENCE_TRACE
+ DMA_FENCE_TRACE
|
- FENCE_WARN
+ DMA_FENCE_WARN
|
- FENCE_ERR
+ DMA_FENCE_ERR
)
 (
 ...
 )

Signed-off-by: Chris Wilson 
Reviewed-by: Gustavo Padovan 
Acked-by: Sumit Semwal 
Acked-by: Christian König 
Signed-off-by: Daniel Vetter 
Link: http://patchwork.freedesktop.org/patch/msgid/20161025120045.28839-1-chris@chris-wilson.co.uk

reservation: add headerdoc comments

2016-05-31T16:42:43+00:00

Signed-off-by: Rob Clark 
Signed-off-by: Sumit Semwal

reservation: add reservation_object_get_excl_rcu()

2016-05-08T14:16:02+00:00

In the atomic modesetting path, each driver simply wants to grab a ref
to the exclusive fence from a reservation object to store in the incoming
drm_plane_state, without doing the whole RCU dance.  Since each driver
will need to do this, lets make a helper.

v2: rename to _rcu instead of _unlocked to be more consistent

Signed-off-by: Rob Clark 
Acked-by: Sumit Semwal

reservation: add suppport for read-only access using rcu

2014-07-08T20:41:08+00:00

This adds some extra functions to deal with rcu.

reservation_object_get_fences_rcu() will obtain the list of shared
and exclusive fences without obtaining the ww_mutex.

reservation_object_wait_timeout_rcu() will wait on all fences of the
reservation_object, without obtaining the ww_mutex.

reservation_object_test_signaled_rcu() will test if all fences of the
reservation_object are signaled without using the ww_mutex.

reservation_object_get_excl and reservation_object_get_list require
the reservation object to be held, updating requires
write_seqcount_begin/end. If only the exclusive fence is needed,
rcu_dereference followed by fence_get_rcu can be used, if the shared
fences are needed it's recommended to use the supplied functions.

Signed-off-by: Maarten Lankhorst 
Acked-by: Sumit Semwal 
Acked-by: Daniel Vetter 
Reviewed-By: Thomas Hellstrom 
Signed-off-by: Greg Kroah-Hartman

reservation: update api and add some helpers

2014-07-08T20:37:35+00:00

Move the list of shared fences to a struct, and return it in
reservation_object_get_list().
Add reservation_object_get_excl to get the exclusive fence.

Add reservation_object_reserve_shared(), which reserves space
in the reservation_object for 1 more shared fence.

reservation_object_add_shared_fence() and
reservation_object_add_excl_fence() are used to assign a new
fence to a reservation_object pointer, to complete a reservation.

Changes since v1:
- Add reservation_object_get_excl, reorder code a bit.

Signed-off-by: Maarten Lankhorst 
Acked-by: Sumit Semwal 
Acked-by: Daniel Vetter 
Signed-off-by: Greg Kroah-Hartman