Whenever we walk along the dma-fence-chain, we prune signaled links to
keep the chain nice and tidy. This leads to situations where we can
prune a link and report the earlier fence as the target seqno --
violating our own consistency checks that the seqno is not more advanced
than the last element in a dma-fence-chain.
Report a NULL fence and success if the seqno has already been signaled.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Tested-by: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota@intel.com>
Reviewed-by: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200409110101.18400-2-chris@chris-wilson.co.uk
Inside dma-fence-chain, we use a cmpxchg on an RCU-protected pointer. To
avoid the sparse warning for using the RCU pointer directly, we have to
cast away the __rcu annotation. However, we don't need to use void*
everywhere and can stick to the dma_fence*.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200409110101.18400-1-chris@chris-wilson.co.uk
We can't free up the chain using recursion or we run into a stack overflow.
Manually free up the dangling chain nodes to avoid recursion.
Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Fixes: 7bf60c52e0 ("dma-buf: add new dma_fence_chain container v7")
Link: https://patchwork.freedesktop.org/patch/321612/
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation this program 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 general public license
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extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 655 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Instead of checking the upper values of the sequence number use an explicit
field in the dma_fence_ops structure to note if a sequence should be 32bit
or 64bit.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Link: https://patchwork.freedesktop.org/patch/299655/
Lockless container implementation similar to a dma_fence_array, but with
only two elements per node and automatic garbage collection.
v2: properly document dma_fence_chain_for_each, add dma_fence_chain_find_seqno,
drop prev reference during garbage collection if it's not a chain fence.
v3: use head and iterator for dma_fence_chain_for_each
v4: fix reference count in dma_fence_chain_enable_signaling
v5: fix iteration when walking each chain node
v6: add __rcu for member 'prev' of struct chain node
v7: fix rcu warnings from kernel robot
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Link: https://patchwork.freedesktop.org/patch/295778/?series=58813&rev=1
Chris Wilson