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author | Ahmed S. Darwish <a.darwish@linutronix.de> | 2020-07-20 17:55:17 +0200 |
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committer | Peter Zijlstra <peterz@infradead.org> | 2020-07-29 16:14:25 +0200 |
commit | 318ce71f3e3ae4108c1665f3860afa8a2a4c9f02 (patch) | |
tree | f14151319fc5982781cbe4dd22a85ca1637437ee /drivers/dma-buf/dma-resv.c | |
parent | ec8702da570ebb59f38471007bf71359c51b027b (diff) | |
download | linux-318ce71f3e3ae4108c1665f3860afa8a2a4c9f02.tar.gz linux-318ce71f3e3ae4108c1665f3860afa8a2a4c9f02.tar.bz2 linux-318ce71f3e3ae4108c1665f3860afa8a2a4c9f02.zip |
dma-buf: Remove custom seqcount lockdep class key
Commit 3c3b177a9369 ("reservation: add support for read-only access
using rcu") introduced a sequence counter to manage updates to
reservations. Back then, the reservation object initializer
reservation_object_init() was always inlined.
Having the sequence counter initialization inlined meant that each of
the call sites would have a different lockdep class key, which would've
broken lockdep's deadlock detection. The aforementioned commit thus
introduced, and exported, a custom seqcount lockdep class key and name.
The commit 8735f16803f00 ("dma-buf: cleanup reservation_object_init...")
transformed the reservation object initializer to a normal non-inlined C
function. seqcount_init(), which automatically defines the seqcount
lockdep class key and must be called non-inlined, can now be safely used.
Remove the seqcount custom lockdep class key, name, and export. Use
seqcount_init() inside the dma reservation object initializer.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://lkml.kernel.org/r/20200720155530.1173732-12-a.darwish@linutronix.de
Diffstat (limited to 'drivers/dma-buf/dma-resv.c')
-rw-r--r-- | drivers/dma-buf/dma-resv.c | 9 |
1 files changed, 1 insertions, 8 deletions
diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c index b45f8514dc82..15efa0c2dacb 100644 --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -51,12 +51,6 @@ DEFINE_WD_CLASS(reservation_ww_class); EXPORT_SYMBOL(reservation_ww_class); -struct lock_class_key reservation_seqcount_class; -EXPORT_SYMBOL(reservation_seqcount_class); - -const char reservation_seqcount_string[] = "reservation_seqcount"; -EXPORT_SYMBOL(reservation_seqcount_string); - /** * dma_resv_list_alloc - allocate fence list * @shared_max: number of fences we need space for @@ -135,9 +129,8 @@ subsys_initcall(dma_resv_lockdep); void dma_resv_init(struct dma_resv *obj) { ww_mutex_init(&obj->lock, &reservation_ww_class); + seqcount_init(&obj->seq); - __seqcount_init(&obj->seq, reservation_seqcount_string, - &reservation_seqcount_class); RCU_INIT_POINTER(obj->fence, NULL); RCU_INIT_POINTER(obj->fence_excl, NULL); } |