[Intel-gfx] [PATCH v3 09/17] drm/i915/vm_bind: Add out fence support
Matthew Auld
matthew.auld at intel.com
Tue Oct 18 14:55:37 UTC 2022
On 14/10/2022 07:48, Niranjana Vishwanathapura wrote:
> On Sun, Oct 09, 2022 at 11:58:18PM -0700, Niranjana Vishwanathapura wrote:
>> Add support for handling out fence for vm_bind call.
>>
>> v2: Reset vma->vm_bind_fence.syncobj to NULL at the end
>> of vm_bind call.
>>
>> Signed-off-by: Niranjana Vishwanathapura
>> <niranjana.vishwanathapura at intel.com>
>> Signed-off-by: Andi Shyti <andi.shyti at linux.intel.com>
>> ---
>> drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h | 4 +
>> .../drm/i915/gem/i915_gem_vm_bind_object.c | 82 +++++++++++++++++++
>> drivers/gpu/drm/i915/i915_vma.c | 7 +-
>> drivers/gpu/drm/i915/i915_vma_types.h | 7 ++
>> include/uapi/drm/i915_drm.h | 63 +++++++++++++-
>> 5 files changed, 158 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h
>> b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h
>> index 36262a6357b5..b70e900e35ab 100644
>> --- a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h
>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h
>> @@ -8,6 +8,7 @@
>>
>> #include <linux/types.h>
>>
>> +struct dma_fence;
>> struct drm_device;
>> struct drm_file;
>> struct i915_address_space;
>> @@ -23,4 +24,7 @@ int i915_gem_vm_unbind_ioctl(struct drm_device *dev,
>> void *data,
>>
>> void i915_gem_vm_unbind_all(struct i915_address_space *vm);
>>
>> +void i915_vm_bind_signal_fence(struct i915_vma *vma,
>> + struct dma_fence * const fence);
>> +
>> #endif /* __I915_GEM_VM_BIND_H */
>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
>> b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
>> index c435d49af2c8..526d3a6bf671 100644
>> --- a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
>> @@ -7,6 +7,8 @@
>>
>> #include <linux/interval_tree_generic.h>
>>
>> +#include <drm/drm_syncobj.h>
>> +
>> #include "gem/i915_gem_context.h"
>> #include "gem/i915_gem_vm_bind.h"
>>
>> @@ -100,6 +102,76 @@ static void i915_gem_vm_bind_remove(struct
>> i915_vma *vma, bool release_obj)
>> i915_gem_object_put(vma->obj);
>> }
>>
>> +static int i915_vm_bind_add_fence(struct drm_file *file, struct
>> i915_vma *vma,
>> + u32 handle, u64 point)
>> +{
>> + struct drm_syncobj *syncobj;
>> +
>> + syncobj = drm_syncobj_find(file, handle);
>> + if (!syncobj) {
>> + DRM_DEBUG("Invalid syncobj handle provided\n");
>> + return -ENOENT;
>> + }
>> +
>> + /*
>> + * For timeline syncobjs we need to preallocate chains for
>> + * later signaling.
>> + */
>> + if (point) {
>> + vma->vm_bind_fence.chain_fence = dma_fence_chain_alloc();
>> + if (!vma->vm_bind_fence.chain_fence) {
>> + drm_syncobj_put(syncobj);
>> + return -ENOMEM;
>> + }
>> + } else {
>> + vma->vm_bind_fence.chain_fence = NULL;
>> + }
>> + vma->vm_bind_fence.syncobj = syncobj;
>> + vma->vm_bind_fence.value = point;
>> +
>> + return 0;
>> +}
>> +
>> +static void i915_vm_bind_put_fence(struct i915_vma *vma)
>> +{
>> + if (!vma->vm_bind_fence.syncobj)
>> + return;
>> +
>> + drm_syncobj_put(vma->vm_bind_fence.syncobj);
>> + dma_fence_chain_free(vma->vm_bind_fence.chain_fence);
>> + vma->vm_bind_fence.syncobj = NULL;
>> +}
>> +
>> +/**
>> + * i915_vm_bind_signal_fence() - Add fence to vm_bind syncobj
>> + * @vma: vma mapping requiring signaling
>> + * @fence: fence to be added
>> + *
>> + * Associate specified @fence with the @vma's syncobj to be
>> + * signaled after the @fence work completes.
>> + */
>> +void i915_vm_bind_signal_fence(struct i915_vma *vma,
>> + struct dma_fence * const fence)
>> +{
>> + struct drm_syncobj *syncobj = vma->vm_bind_fence.syncobj;
>> +
>> + if (!syncobj)
>> + return;
>> +
>> + if (vma->vm_bind_fence.chain_fence) {
>> + drm_syncobj_add_point(syncobj,
>> + vma->vm_bind_fence.chain_fence,
>> + fence, vma->vm_bind_fence.value);
>> + /*
>> + * The chain's ownership is transferred to the
>> + * timeline.
>> + */
>> + vma->vm_bind_fence.chain_fence = NULL;
>> + } else {
>> + drm_syncobj_replace_fence(syncobj, fence);
>> + }
>> +}
>> +
>> static int i915_gem_vm_unbind_vma(struct i915_address_space *vm,
>> struct drm_i915_gem_vm_unbind *va)
>> {
>> @@ -237,6 +309,13 @@ static int i915_gem_vm_bind_obj(struct
>> i915_address_space *vm,
>> goto unlock_vm;
>> }
>>
>> + if (va->fence.flags & I915_TIMELINE_FENCE_SIGNAL) {
>> + ret = i915_vm_bind_add_fence(file, vma, va->fence.handle,
>> + va->fence.value);
>> + if (ret)
>> + goto put_vma;
>> + }
>> +
>> pin_flags = va->start | PIN_OFFSET_FIXED | PIN_USER | PIN_VALIDATE;
>>
>> for_i915_gem_ww(&ww, ret, true) {
>> @@ -258,6 +337,9 @@ static int i915_gem_vm_bind_obj(struct
>> i915_address_space *vm,
>> i915_gem_object_get(vma->obj);
>> }
>>
>> + if (va->fence.flags & I915_TIMELINE_FENCE_SIGNAL)
>> + i915_vm_bind_put_fence(vma);
>> +put_vma:
>> if (ret)
>> i915_vma_destroy(vma);
>> unlock_vm:
>> diff --git a/drivers/gpu/drm/i915/i915_vma.c
>> b/drivers/gpu/drm/i915/i915_vma.c
>> index 88c09e885fec..cb8e718ec46e 100644
>> --- a/drivers/gpu/drm/i915/i915_vma.c
>> +++ b/drivers/gpu/drm/i915/i915_vma.c
>> @@ -29,6 +29,7 @@
>> #include "display/intel_frontbuffer.h"
>> #include "gem/i915_gem_lmem.h"
>> #include "gem/i915_gem_tiling.h"
>> +#include "gem/i915_gem_vm_bind.h"
>> #include "gt/intel_engine.h"
>> #include "gt/intel_engine_heartbeat.h"
>> #include "gt/intel_gt.h"
>> @@ -1572,8 +1573,12 @@ int i915_vma_pin_ww(struct i915_vma *vma,
>> struct i915_gem_ww_ctx *ww,
>> err_vma_res:
>> i915_vma_resource_free(vma_res);
>> err_fence:
>> - if (work)
>> + if (work) {
>> + if (i915_vma_is_persistent(vma))
>> + i915_vm_bind_signal_fence(vma, &work->base.dma);
>> +
>> dma_fence_work_commit_imm(&work->base);
>> + }
>> err_rpm:
>> if (wakeref)
>> intel_runtime_pm_put(&vma->vm->i915->runtime_pm, wakeref);
>> diff --git a/drivers/gpu/drm/i915/i915_vma_types.h
>> b/drivers/gpu/drm/i915/i915_vma_types.h
>> index d32c72e8d242..2c740500ac1b 100644
>> --- a/drivers/gpu/drm/i915/i915_vma_types.h
>> +++ b/drivers/gpu/drm/i915/i915_vma_types.h
>> @@ -308,6 +308,13 @@ struct i915_vma {
>> /* @vm_rebind_link: link to vm_rebind_list and protected by
>> vm_rebind_lock */
>> struct list_head vm_rebind_link; /* Link in vm_rebind_list */
>>
>> + /** Timeline fence for vm_bind completion notification */
>> + struct {
>> + struct dma_fence_chain *chain_fence;
>> + struct drm_syncobj *syncobj;
>> + u64 value;
>> + } vm_bind_fence;
>> +
>> /** Interval tree structures for persistent vma */
>>
>> /** @rb: node for the interval tree of vm for persistent vmas */
>> diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
>> index 16b815875e4f..61b1500866f9 100644
>> --- a/include/uapi/drm/i915_drm.h
>> +++ b/include/uapi/drm/i915_drm.h
>> @@ -1527,6 +1527,41 @@ struct drm_i915_gem_execbuffer2 {
>> #define i915_execbuffer2_get_context_id(eb2) \
>> ((eb2).rsvd1 & I915_EXEC_CONTEXT_ID_MASK)
>>
>> +/**
>> + * struct drm_i915_gem_timeline_fence - An input or output timeline
>> fence.
>> + *
>> + * The operation will wait for input fence to signal.
>> + *
>> + * The returned output fence will be signaled after the completion of
>> the
>> + * operation.
>> + */
>> +struct drm_i915_gem_timeline_fence {
>> + /** @handle: User's handle for a drm_syncobj to wait on or
>> signal. */
>> + __u32 handle;
>> +
>> + /**
>> + * @flags: Supported flags are:
>> + *
>> + * I915_TIMELINE_FENCE_WAIT:
>> + * Wait for the input fence before the operation.
>> + *
>> + * I915_TIMELINE_FENCE_SIGNAL:
>> + * Return operation completion fence as output.
>> + */
>> + __u32 flags;
>> +#define I915_TIMELINE_FENCE_WAIT (1 << 0)
>> +#define I915_TIMELINE_FENCE_SIGNAL (1 << 1)
>> +#define __I915_TIMELINE_FENCE_UNKNOWN_FLAGS
>> (-(I915_TIMELINE_FENCE_SIGNAL << 1))
>> +
>> + /**
>> + * @value: A point in the timeline.
>> + * Value must be 0 for a binary drm_syncobj. A Value of 0 for a
>> + * timeline drm_syncobj is invalid as it turns a drm_syncobj into a
>> + * binary one.
>> + */
>> + __u64 value;
>> +};
>> +
>> struct drm_i915_gem_pin {
>> /** Handle of the buffer to be pinned. */
>> __u32 handle;
>> @@ -3817,8 +3852,18 @@ struct drm_i915_gem_vm_bind {
>> */
>> __u64 flags;
>>
>> - /** @rsvd: Reserved, MBZ */
>> - __u64 rsvd[2];
>> + /**
>> + * @fence: Timeline fence for bind completion signaling.
>> + *
>> + * Timeline fence is of format struct drm_i915_gem_timeline_fence.
>> + *
>> + * It is an out fence, hence using I915_TIMELINE_FENCE_WAIT flag
>> + * is invalid, and an error will be returned.
>> + *
>> + * If I915_TIMELINE_FENCE_SIGNAL flag is not set, then out fence
>> + * is not requested and binding is completed synchronously.
>> + */
>> + struct drm_i915_gem_timeline_fence fence;
>>
>> /**
>> * @extensions: Zero-terminated chain of extensions.
>> @@ -3865,8 +3910,18 @@ struct drm_i915_gem_vm_unbind {
>> */
>> __u64 flags;
>>
>> - /** @rsvd2: Reserved, MBZ */
>> - __u64 rsvd2[2];
>> + /**
>> + * @fence: Timeline fence for unbind completion signaling.
>> + *
>> + * Timeline fence is of format struct drm_i915_gem_timeline_fence.
>> + *
>> + * It is an out fence, hence using I915_TIMELINE_FENCE_WAIT flag
>> + * is invalid, and an error will be returned.
>> + *
>> + * If I915_TIMELINE_FENCE_SIGNAL flag is not set, then out fence
>> + * is not requested and unbinding is completed synchronously.
>> + */
>> + struct drm_i915_gem_timeline_fence fence;
>
> Async unbind (hence out fence) is not yet supported for vm_unbind call.
>
> Also, looking at i915_vma_unbind_async(), we can use that for async
> vm_unbind support. The i915 driver also handles sequencing of other
> operations behind the async unbind. Hence, probably we don't need to
> return the out fence to user at all here.
> i915_vma_unbind_async() works only for objects with ttm backend.
> Perhaps for other objects (like userptr) and if async unbind returns
> error, we can fallback to synchronous vma unbind (i915_vma_unbind()).
>
> So, not sure whether we really need timeline out fence support here.
> I will remove this udate here and keep the fields as reserved for now.
> Any thoughts?
That seems reasonable to me, unless there is some other usecase for the
out fence on unbind...
>
> Thanks,
> Niranjana
>
>>
>> /**
>> * @extensions: Zero-terminated chain of extensions.
>> --
>> 2.21.0.rc0.32.g243a4c7e27
>>
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