From: Tvrtko Ursulin Date: Thu, 15 May 2025 09:49:57 +0000 (+0100) Subject: dma-fence: Use a flag for 64-bit seqnos X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bf33a0003d9e3b0546f2d7e91bebfd67af59f275;p=thirdparty%2Flinux.git dma-fence: Use a flag for 64-bit seqnos With the goal of reducing the need for drivers to touch (and dereference) fence->ops, we move the 64-bit seqnos flag from struct dma_fence_ops to the fence->flags. Drivers which were setting this flag are changed to use new dma_fence_init64() instead of dma_fence_init(). v2: * Streamlined init and added kerneldoc. * Rebase for amdgpu userq which landed since. Signed-off-by: Tvrtko Ursulin Reviewed-by: Christian König # v1 Signed-off-by: Tvrtko Ursulin Link: https://lore.kernel.org/r/20250515095004.28318-3-tvrtko.ursulin@igalia.com --- diff --git a/drivers/dma-buf/dma-fence-chain.c b/drivers/dma-buf/dma-fence-chain.c index 90424f23fd733..a8a90acf4f34d 100644 --- a/drivers/dma-buf/dma-fence-chain.c +++ b/drivers/dma-buf/dma-fence-chain.c @@ -218,7 +218,6 @@ static void dma_fence_chain_set_deadline(struct dma_fence *fence, } const struct dma_fence_ops dma_fence_chain_ops = { - .use_64bit_seqno = true, .get_driver_name = dma_fence_chain_get_driver_name, .get_timeline_name = dma_fence_chain_get_timeline_name, .enable_signaling = dma_fence_chain_enable_signaling, @@ -262,8 +261,8 @@ void dma_fence_chain_init(struct dma_fence_chain *chain, seqno = max(prev->seqno, seqno); } - dma_fence_init(&chain->base, &dma_fence_chain_ops, - &chain->lock, context, seqno); + dma_fence_init64(&chain->base, &dma_fence_chain_ops, &chain->lock, + context, seqno); /* * Chaining dma_fence_chain container together is only allowed through diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index f0cdd3e99d369..705b597877319 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c @@ -989,6 +989,25 @@ void dma_fence_describe(struct dma_fence *fence, struct seq_file *seq) } EXPORT_SYMBOL(dma_fence_describe); +static void +__dma_fence_init(struct dma_fence *fence, const struct dma_fence_ops *ops, + spinlock_t *lock, u64 context, u64 seqno, unsigned long flags) +{ + BUG_ON(!lock); + BUG_ON(!ops || !ops->get_driver_name || !ops->get_timeline_name); + + kref_init(&fence->refcount); + fence->ops = ops; + INIT_LIST_HEAD(&fence->cb_list); + fence->lock = lock; + fence->context = context; + fence->seqno = seqno; + fence->flags = flags; + fence->error = 0; + + trace_dma_fence_init(fence); +} + /** * dma_fence_init - Initialize a custom fence. * @fence: the fence to initialize @@ -1008,18 +1027,30 @@ void dma_fence_init(struct dma_fence *fence, const struct dma_fence_ops *ops, spinlock_t *lock, u64 context, u64 seqno) { - BUG_ON(!lock); - BUG_ON(!ops || !ops->get_driver_name || !ops->get_timeline_name); - - kref_init(&fence->refcount); - fence->ops = ops; - INIT_LIST_HEAD(&fence->cb_list); - fence->lock = lock; - fence->context = context; - fence->seqno = seqno; - fence->flags = 0UL; - fence->error = 0; - - trace_dma_fence_init(fence); + __dma_fence_init(fence, ops, lock, context, seqno, 0UL); } EXPORT_SYMBOL(dma_fence_init); + +/** + * dma_fence_init64 - Initialize a custom fence with 64-bit seqno support. + * @fence: the fence to initialize + * @ops: the dma_fence_ops for operations on this fence + * @lock: the irqsafe spinlock to use for locking this fence + * @context: the execution context this fence is run on + * @seqno: a linear increasing sequence number for this context + * + * Initializes an allocated fence, the caller doesn't have to keep its + * refcount after committing with this fence, but it will need to hold a + * refcount again if &dma_fence_ops.enable_signaling gets called. + * + * Context and seqno are used for easy comparison between fences, allowing + * to check which fence is later by simply using dma_fence_later(). + */ +void +dma_fence_init64(struct dma_fence *fence, const struct dma_fence_ops *ops, + spinlock_t *lock, u64 context, u64 seqno) +{ + __dma_fence_init(fence, ops, lock, context, seqno, + BIT(DMA_FENCE_FLAG_SEQNO64_BIT)); +} +EXPORT_SYMBOL(dma_fence_init64); diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c index 73b629b5f56fc..ce621f88ddcac 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c @@ -134,7 +134,6 @@ static bool amdgpu_eviction_fence_enable_signaling(struct dma_fence *f) } static const struct dma_fence_ops amdgpu_eviction_fence_ops = { - .use_64bit_seqno = true, .get_driver_name = amdgpu_eviction_fence_get_driver_name, .get_timeline_name = amdgpu_eviction_fence_get_timeline_name, .enable_signaling = amdgpu_eviction_fence_enable_signaling, @@ -160,9 +159,9 @@ amdgpu_eviction_fence_create(struct amdgpu_eviction_fence_mgr *evf_mgr) ev_fence->evf_mgr = evf_mgr; get_task_comm(ev_fence->timeline_name, current); spin_lock_init(&ev_fence->lock); - dma_fence_init(&ev_fence->base, &amdgpu_eviction_fence_ops, - &ev_fence->lock, evf_mgr->ev_fence_ctx, - atomic_inc_return(&evf_mgr->ev_fence_seq)); + dma_fence_init64(&ev_fence->base, &amdgpu_eviction_fence_ops, + &ev_fence->lock, evf_mgr->ev_fence_ctx, + atomic_inc_return(&evf_mgr->ev_fence_seq)); return ev_fence; } diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c index fc4d0d42e2238..a3db9442dc376 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c @@ -239,8 +239,8 @@ static int amdgpu_userq_fence_create(struct amdgpu_usermode_queue *userq, fence = &userq_fence->base; userq_fence->fence_drv = fence_drv; - dma_fence_init(fence, &amdgpu_userq_fence_ops, &userq_fence->lock, - fence_drv->context, seq); + dma_fence_init64(fence, &amdgpu_userq_fence_ops, &userq_fence->lock, + fence_drv->context, seq); amdgpu_userq_fence_driver_get(fence_drv); dma_fence_get(fence); @@ -334,7 +334,6 @@ static void amdgpu_userq_fence_release(struct dma_fence *f) } static const struct dma_fence_ops amdgpu_userq_fence_ops = { - .use_64bit_seqno = true, .get_driver_name = amdgpu_userq_fence_get_driver_name, .get_timeline_name = amdgpu_userq_fence_get_timeline_name, .signaled = amdgpu_userq_fence_signaled, diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_tlb_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_tlb_fence.c index 51cddfa3f1e8f..5d26797356a38 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_tlb_fence.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_tlb_fence.c @@ -71,7 +71,6 @@ static void amdgpu_tlb_fence_work(struct work_struct *work) } static const struct dma_fence_ops amdgpu_tlb_fence_ops = { - .use_64bit_seqno = true, .get_driver_name = amdgpu_tlb_fence_get_driver_name, .get_timeline_name = amdgpu_tlb_fence_get_timeline_name }; @@ -101,8 +100,8 @@ void amdgpu_vm_tlb_fence_create(struct amdgpu_device *adev, struct amdgpu_vm *vm INIT_WORK(&f->work, amdgpu_tlb_fence_work); spin_lock_init(&f->lock); - dma_fence_init(&f->base, &amdgpu_tlb_fence_ops, &f->lock, - vm->tlb_fence_context, atomic64_read(&vm->tlb_seq)); + dma_fence_init64(&f->base, &amdgpu_tlb_fence_ops, &f->lock, + vm->tlb_fence_context, atomic64_read(&vm->tlb_seq)); /* TODO: We probably need a separate wq here */ dma_fence_get(&f->base); diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index c841af28b7066..926c01b5b29d3 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -98,6 +98,7 @@ struct dma_fence { }; enum dma_fence_flag_bits { + DMA_FENCE_FLAG_SEQNO64_BIT, DMA_FENCE_FLAG_SIGNALED_BIT, DMA_FENCE_FLAG_TIMESTAMP_BIT, DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, @@ -125,14 +126,6 @@ struct dma_fence_cb { * */ struct dma_fence_ops { - /** - * @use_64bit_seqno: - * - * True if this dma_fence implementation uses 64bit seqno, false - * otherwise. - */ - bool use_64bit_seqno; - /** * @get_driver_name: * @@ -263,6 +256,9 @@ struct dma_fence_ops { void dma_fence_init(struct dma_fence *fence, const struct dma_fence_ops *ops, spinlock_t *lock, u64 context, u64 seqno); +void dma_fence_init64(struct dma_fence *fence, const struct dma_fence_ops *ops, + spinlock_t *lock, u64 context, u64 seqno); + void dma_fence_release(struct kref *kref); void dma_fence_free(struct dma_fence *fence); void dma_fence_describe(struct dma_fence *fence, struct seq_file *seq); @@ -455,7 +451,7 @@ static inline bool __dma_fence_is_later(struct dma_fence *fence, u64 f1, u64 f2) * 32bit sequence numbers. Use a 64bit compare when the driver says to * do so. */ - if (fence->ops->use_64bit_seqno) + if (test_bit(DMA_FENCE_FLAG_SEQNO64_BIT, &fence->flags)) return f1 > f2; return (int)(lower_32_bits(f1) - lower_32_bits(f2)) > 0;