[PATCH v4 2/9] dma-fence: Use a flag for 64-bit seqnos
Tvrtko Ursulin
tvrtko.ursulin at igalia.com
Thu May 15 09:49:57 UTC 2025
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 <tvrtko.ursulin at igalia.com>
Reviewed-by: Christian König <christian.koenig at amd.com> # v1
---
drivers/dma-buf/dma-fence-chain.c | 5 +-
drivers/dma-buf/dma-fence.c | 69 ++++++++++++++-----
.../drm/amd/amdgpu/amdgpu_eviction_fence.c | 7 +-
.../gpu/drm/amd/amdgpu/amdgpu_userq_fence.c | 5 +-
.../gpu/drm/amd/amdgpu/amdgpu_vm_tlb_fence.c | 5 +-
include/linux/dma-fence.h | 14 ++--
6 files changed, 64 insertions(+), 41 deletions(-)
diff --git a/drivers/dma-buf/dma-fence-chain.c b/drivers/dma-buf/dma-fence-chain.c
index 90424f23fd73..a8a90acf4f34 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 f0cdd3e99d36..705b59787731 100644
--- a/drivers/dma-buf/dma-fence.c
+++ b/drivers/dma-buf/dma-fence.c
@@ -989,24 +989,9 @@ void dma_fence_describe(struct dma_fence *fence, struct seq_file *seq)
}
EXPORT_SYMBOL(dma_fence_describe);
-/**
- * dma_fence_init - Initialize a custom fence.
- * @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_init(struct dma_fence *fence, const struct dma_fence_ops *ops,
- spinlock_t *lock, u64 context, u64 seqno)
+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);
@@ -1017,9 +1002,55 @@ dma_fence_init(struct dma_fence *fence, const struct dma_fence_ops *ops,
fence->lock = lock;
fence->context = context;
fence->seqno = seqno;
- fence->flags = 0UL;
+ fence->flags = flags;
fence->error = 0;
trace_dma_fence_init(fence);
}
+
+/**
+ * dma_fence_init - Initialize a custom fence.
+ * @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_init(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, 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 1a7469543db5..79713421bffe 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 029cb24c28b3..5e92d00a591f 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 51cddfa3f1e8..5d26797356a3 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 48b5202c531d..a34a0dcdc446 100644
--- a/include/linux/dma-fence.h
+++ b/include/linux/dma-fence.h
@@ -97,6 +97,7 @@ 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,
@@ -124,14 +125,6 @@ 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:
*
@@ -262,6 +255,9 @@ 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);
@@ -454,7 +450,7 @@ 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;
--
2.48.0
More information about the Intel-gfx
mailing list