[PATCH v6 2/5] drm/xe: Strict migration policy for atomic SVM faults

Thomas Hellström thomas.hellstrom at linux.intel.com
Thu May 8 13:25:08 UTC 2025


Hi, Matthew.

On Wed, 2025-05-07 at 08:41 -0700, Matthew Brost wrote:
> On Wed, May 07, 2025 at 02:01:56PM +0200, Thomas Hellström wrote:
> > 
> > This is v7, right? (Says v6 in the subject).
> > 
> 
> Yea, I somehow mismatched version in change log and patches sent.
> 
> Ok, getting a little bogged down on comments, let try fix them inline
> in
> this reply to make sure they look good before sending next rev.

So since we're not adhering to the drm locking guidelines, I want to
ensure that what we ask to PULL is at least properly documented. So
what I've been asking here is two things.

1) If the intended usage of a function is advisory / opportunistic,
please document that at the function header rather than as a comment
within the function definition.

2) Document what a barrier / READ_ONCE / WRITE_ONCE pairs with. Ideally
pointing to the specific function.

In particular for 1) I've mentioned it a couple of times without it
beeing addressed or commented on so that's why I'm bringing it up again
in case it was missed.

So let's check.

> 
> > On Tue, 2025-05-06 at 16:01 -0700, Matthew Brost wrote:
> > > Mixing GPU and CPU atomics does not work unless a strict
> > > migration
> > > policy of GPU atomics must be device memory. Enforce a policy of
> > > must
> > > be
> > > in VRAM with a retry loop of 3 attempts, if retry loop fails
> > > abort
> > > fault.
> > > 
> > > Removing always_migrate_to_vram modparam as we now have real
> > > migration
> > > policy.
> > > 
> > > v2:
> > >  - Only retry migration on atomics
> > >  - Drop alway migrate modparam
> > > v3:
> > >  - Only set vram_only on DGFX (Himal)
> > >  - Bail on get_pages failure if vram_only and retry count
> > > exceeded
> > > (Himal)
> > >  - s/vram_only/devmem_only
> > >  - Update xe_svm_range_is_valid to accept devmem_only argument
> > > v4:
> > >  - Fix logic bug get_pages failure
> > > v5:
> > >  - Fix commit message (Himal)
> > >  - Mention removing always_migrate_to_vram in commit message
> > > (Lucas)
> > >  - Fix xe_svm_range_is_valid to check for devmem pages
> > >  - Bail on devmem_only && !migrate_devmem (Thomas)
> > > v6:
> > >  - Add READ_ONCE barriers for opportunistic checks (Thomas)
> > > v7:
> > >  - Pair READ_ONCE with WRITE_ONCE (Thomas)
> > > 
> > > Fixes: 2f118c949160 ("drm/xe: Add SVM VRAM migration")
> > > Cc: stable at vger.kernel.org
> > > Signed-off-by: Himal Prasad Ghimiray
> > > <himal.prasad.ghimiray at intel.com>
> > > Signed-off-by: Matthew Brost <matthew.brost at intel.com>
> > > Acked-by: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
> > > ---
> > >  drivers/gpu/drm/drm_gpusvm.c   |  23 +++++--
> > >  drivers/gpu/drm/xe/xe_module.c |   3 -
> > >  drivers/gpu/drm/xe/xe_module.h |   1 -
> > >  drivers/gpu/drm/xe/xe_pt.c     |  14 ++++-
> > >  drivers/gpu/drm/xe/xe_svm.c    | 109 +++++++++++++++++++++++++--
> > > ----
> > > --
> > >  drivers/gpu/drm/xe/xe_svm.h    |   5 --
> > >  include/drm/drm_gpusvm.h       |  40 +++++++-----
> > >  7 files changed, 138 insertions(+), 57 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/drm_gpusvm.c
> > > b/drivers/gpu/drm/drm_gpusvm.c
> > > index a58d03e6cac2..41f6616bcf76 100644
> > > --- a/drivers/gpu/drm/drm_gpusvm.c
> > > +++ b/drivers/gpu/drm/drm_gpusvm.c
> > > @@ -1118,6 +1118,10 @@ static void
> > > __drm_gpusvm_range_unmap_pages(struct drm_gpusvm *gpusvm,
> > >  	lockdep_assert_held(&gpusvm->notifier_lock);
> > >  
> > >  	if (range->flags.has_dma_mapping) {
> > > +		struct drm_gpusvm_range_flags flags = {
> > > +			.__flags = range->flags.__flags,
> > > +		};
> > > +
> > >  		for (i = 0, j = 0; i < npages; j++) {
> > >  			struct drm_pagemap_device_addr *addr =
> > > &range->dma_addr[j];
> > >  
> > > @@ -1131,8 +1135,12 @@ static void
> > > __drm_gpusvm_range_unmap_pages(struct drm_gpusvm *gpusvm,
> > >  							    dev,
> > > *addr);
> > >  			i += 1 << addr->order;
> > >  		}
> > > -		range->flags.has_devmem_pages = false;
> > > -		range->flags.has_dma_mapping = false;
> > > +
> > > +		/* WRITE_ONCE pairs with READ_ONCE for
> > > opportunistic
> > > checks */
> 
> Is this one ok? Can't really quote driver side here...

Yeah makes sense.

> 
> > > +		flags.has_devmem_pages = false;
> > > +		flags.has_dma_mapping = false;
> > > +		WRITE_ONCE(range->flags.__flags, flags.__flags);
> > > +
> > >  		range->dpagemap = NULL;
> > >  	}
> > >  }
> > > @@ -1334,6 +1342,7 @@ int drm_gpusvm_range_get_pages(struct
> > > drm_gpusvm *gpusvm,
> > >  	int err = 0;
> > >  	struct dev_pagemap *pagemap;
> > >  	struct drm_pagemap *dpagemap;
> > > +	struct drm_gpusvm_range_flags flags;
> > >  
> > >  retry:
> > >  	hmm_range.notifier_seq =
> > > mmu_interval_read_begin(notifier);
> > > @@ -1378,7 +1387,8 @@ int drm_gpusvm_range_get_pages(struct
> > > drm_gpusvm *gpusvm,
> > >  	 */
> > >  	drm_gpusvm_notifier_lock(gpusvm);
> > >  
> > > -	if (range->flags.unmapped) {
> > > +	flags.__flags = range->flags.__flags;
> > > +	if (flags.unmapped) {
> > >  		drm_gpusvm_notifier_unlock(gpusvm);
> > >  		err = -EFAULT;
> > >  		goto err_free;
> > > @@ -1474,14 +1484,17 @@ int drm_gpusvm_range_get_pages(struct
> > > drm_gpusvm *gpusvm,
> > >  		}
> > >  		i += 1 << order;
> > >  		num_dma_mapped = i;
> > > -		range->flags.has_dma_mapping = true;
> > > +		flags.has_dma_mapping = true;
> > >  	}
> > >  
> > >  	if (zdd) {
> > > -		range->flags.has_devmem_pages = true;
> > > +		flags.has_devmem_pages = true;
> > >  		range->dpagemap = dpagemap;
> > >  	}
> > >  
> > > +	/* WRITE_ONCE pairs with READ_ONCE for opportunistic
> > > checks
> > > */
> 
> Same as above.

Makes sense.



> 
> > > +	WRITE_ONCE(range->flags.__flags, flags.__flags);
> > > +
> > >  	drm_gpusvm_notifier_unlock(gpusvm);
> > >  	kvfree(pfns);
> > >  set_seqno:
> > > diff --git a/drivers/gpu/drm/xe/xe_module.c
> > > b/drivers/gpu/drm/xe/xe_module.c
> > > index 05c7d0ae6d83..1c4dfafbcd0b 100644
> > > --- a/drivers/gpu/drm/xe/xe_module.c
> > > +++ b/drivers/gpu/drm/xe/xe_module.c
> > > @@ -33,9 +33,6 @@ struct xe_modparam xe_modparam = {
> > >  module_param_named(svm_notifier_size,
> > > xe_modparam.svm_notifier_size,
> > > uint, 0600);
> > >  MODULE_PARM_DESC(svm_notifier_size, "Set the svm notifier
> > > size(in
> > > MiB), must be power of 2");
> > >  
> > > -module_param_named(always_migrate_to_vram,
> > > xe_modparam.always_migrate_to_vram, bool, 0444);
> > > -MODULE_PARM_DESC(always_migrate_to_vram, "Always migrate to VRAM
> > > on
> > > GPU fault");
> > > -
> > >  module_param_named_unsafe(force_execlist,
> > > xe_modparam.force_execlist, bool, 0444);
> > >  MODULE_PARM_DESC(force_execlist, "Force Execlist submission");
> > >  
> > > diff --git a/drivers/gpu/drm/xe/xe_module.h
> > > b/drivers/gpu/drm/xe/xe_module.h
> > > index 84339e509c80..5a3bfea8b7b4 100644
> > > --- a/drivers/gpu/drm/xe/xe_module.h
> > > +++ b/drivers/gpu/drm/xe/xe_module.h
> > > @@ -12,7 +12,6 @@
> > >  struct xe_modparam {
> > >  	bool force_execlist;
> > >  	bool probe_display;
> > > -	bool always_migrate_to_vram;
> > >  	u32 force_vram_bar_size;
> > >  	int guc_log_level;
> > >  	char *guc_firmware_path;
> > > diff --git a/drivers/gpu/drm/xe/xe_pt.c
> > > b/drivers/gpu/drm/xe/xe_pt.c
> > > index b42cf5d1b20c..b487e094178d 100644
> > > --- a/drivers/gpu/drm/xe/xe_pt.c
> > > +++ b/drivers/gpu/drm/xe/xe_pt.c
> > > @@ -2270,11 +2270,19 @@ static void op_commit(struct xe_vm *vm,
> > >  	}
> > >  	case DRM_GPUVA_OP_DRIVER:
> > >  	{
> > > +		/* WRITE_ONCE pairs with READ_ONCE opportunistic
> > > checks */
> > > +
> 
> /* WRITE_ONCE pairs with READ_ONCE in xe_svm.c */

Fine.

> 
> > >  		if (op->subop == XE_VMA_SUBOP_MAP_RANGE) {
> > > -			op->map_range.range->tile_present |=
> > > BIT(tile->id);
> > > -			op->map_range.range->tile_invalidated &=
> > > ~BIT(tile->id);
> > > +			WRITE_ONCE(op->map_range.range-
> > > > tile_present,
> > > +				   op->map_range.range-
> > > >tile_present
> > > > 
> > > +				   BIT(tile->id));
> > > +			WRITE_ONCE(op->map_range.range-
> > > > tile_invalidated,
> > > +				   op->map_range.range-
> > > > tile_invalidated &
> > > +				   ~BIT(tile->id));
> > >  		} else if (op->subop ==
> > > XE_VMA_SUBOP_UNMAP_RANGE) {
> > > -			op->unmap_range.range->tile_present &=
> > > ~BIT(tile->id);
> > > +			WRITE_ONCE(op->unmap_range.range-
> > > > tile_present,
> > > +				   op->unmap_range.range-
> > > > tile_present &
> > > +				   ~BIT(tile->id));
> > >  		}
> > >  		break;
> > >  	}
> > > diff --git a/drivers/gpu/drm/xe/xe_svm.c
> > > b/drivers/gpu/drm/xe/xe_svm.c
> > > index 890f6b2f40e9..8c0ef55cfd57 100644
> > > --- a/drivers/gpu/drm/xe/xe_svm.c
> > > +++ b/drivers/gpu/drm/xe/xe_svm.c
> > > @@ -16,8 +16,15 @@
> > >  
> > 
> > So what I meant in the review comments is something along
> > 
> > /* Advisory only check whether the range is currently backed by
> > VRAM
> > memory. */
> > 
> > (As said we shouldn need to look at the function implementation to
> > understand that it's opportunistic).
> > 
> > >  static bool xe_svm_range_in_vram(struct xe_svm_range *range)
> > >  {
> > > -	/* Not reliable without notifier lock */
> > > -	return range->base.flags.has_devmem_pages;
> > > +	/*
> > > +	 * Not reliable without notifier lock, opportunistic
> > > only,
> > > pairs with
> > > +	 * WRITE_ONCE
> > 
> > So if we assume that this function should is never be called with
> > the
> > notifier lock held, we can leave that comment out, just
> > 
> > /* Pairs with WRITE_ONCE() in xe_pt.c */ 
> > 
> > 
> > And similar for the other places.
> > 
> > Thanks,
> > Thomas
> > 
> > > +	 */
> 
> /*
>  * Advisory only check whether the range is currently backed by VRAM
>  * memory, READ_ONCE pairs with WRITE_ONCE in drm_gpusvm.c
>  */
> 

Here I'd put the READ_ONCE part of the comment where it's actually
used.

> > > +	struct drm_gpusvm_range_flags flags = {
/* Pairs with WRITE_ONCE() in drm_gpusvm.c */
> > > +		.__flags = READ_ONCE(range->base.flags.__flags),
> > > +	};
> > > +
> > > +	return flags.has_devmem_pages;
> > >  }
> > >  
> > >  static bool xe_svm_range_has_vram_binding(struct xe_svm_range
> > > *range)
> > > @@ -650,9 +657,16 @@ void xe_svm_fini(struct xe_vm *vm)
> > >  }
> > >  
> > >  static bool xe_svm_range_is_valid(struct xe_svm_range *range,
> > > -				  struct xe_tile *tile)
> > > +				  struct xe_tile *tile,
> > > +				  bool devmem_only)
> > >  {
> > > -	return (range->tile_present & ~range->tile_invalidated)
> > > &
> > > BIT(tile->id);
> > > +	/*
> > > +	 * Not reliable without notifier lock, opportunistic
> > > only,
> > > pairs with
> > > +	 * WRITE_ONCE
> > > +	 */
> 
> /*
>  * Advisory only check whether the range currently has a valid
> mapping,
>  * READ_ONCE pairs with WRITE_ONCE in xe_pt.c
>  */
> 
> > > +	return ((READ_ONCE(range->tile_present) &
> > > +		 ~READ_ONCE(range->tile_invalidated)) &
> > > BIT(tile-
> > > > id)) &&
> > > +		(!devmem_only || xe_svm_range_in_vram(range));
> > >  }
> > >  
> > >  #if IS_ENABLED(CONFIG_DRM_XE_DEVMEM_MIRROR)
> > > @@ -726,6 +740,36 @@ static int xe_svm_alloc_vram(struct xe_vm
> > > *vm,static bool supports_4K_migration(struct xe_device *xe)
> > > +{
> > > +	if (xe->info.vram_flags & XE_VRAM_FLAGS_NEED64K)
> > > +		return false;
> > > +
> > > +	return true;
> > > +}
> > > +
> > > +static bool xe_svm_range_needs_migrate_to_vram(struct
> > > xe_svm_range
> > > *range,
> > > +					       struct xe_vma
> > > *vma)
> > > +{
> > > +	struct xe_vm *vm = range_to_vm(&range->base);
> > > +	u64 range_size = xe_svm_range_size(range);
> > > +
> > > +	if (!range->base.flags.migrate_devmem)
> > > +		return false;
> > > +
> > > +	/* Not reliable without notifier lock, opportunistic
> > > only */
> 
> Drop this one as xe_svm_range_in_vram has a comment.
Yes,

Thanks,
Thomas


> 
> Matt
> 
> > > +	if (xe_svm_range_in_vram(range)) {
> > > +		drm_dbg(&vm->xe->drm, "Range is already in
> > > VRAM\n");
> > > +		return false;
> > > +	}
> > > +
> > > +	if (range_size <= SZ_64K && !supports_4K_migration(vm-
> > > >xe))
> > > {
> > > +		drm_dbg(&vm->xe->drm, "Platform doesn't support
> > > SZ_4K range migration\n");
> > > +		return false;
> > > +	}
> > > +
> > > +	return true;
> > > +}
> > >  
> > >  /**
> > >   * xe_svm_handle_pagefault() - SVM handle page fault
> > > @@ -750,12 +794,15 @@ int xe_svm_handle_pagefault(struct xe_vm
> > > *vm,
> > > struct xe_vma *vma,
> > >  			IS_ENABLED(CONFIG_DRM_XE_DEVMEM_MIRROR),
> > >  		.check_pages_threshold = IS_DGFX(vm->xe) &&
> > >  			IS_ENABLED(CONFIG_DRM_XE_DEVMEM_MIRROR)
> > > ?
> > > SZ_64K : 0,
> > > +		.devmem_only = atomic && IS_DGFX(vm->xe) &&
> > > +			IS_ENABLED(CONFIG_DRM_XE_DEVMEM_MIRROR),
> > >  	};
> > >  	struct xe_svm_range *range;
> > >  	struct drm_gpusvm_range *r;
> > >  	struct drm_exec exec;
> > >  	struct dma_fence *fence;
> > >  	struct xe_tile *tile = gt_to_tile(gt);
> > > +	int migrate_try_count = ctx.devmem_only ? 3 : 1;
> > >  	ktime_t end = 0;
> > >  	int err;
> > >  
> > > @@ -776,24 +823,30 @@ int xe_svm_handle_pagefault(struct xe_vm
> > > *vm,
> > > struct xe_vma *vma,
> > >  	if (IS_ERR(r))
> > >  		return PTR_ERR(r);
> > >  
> > > +	if (ctx.devmem_only && !r->flags.migrate_devmem)
> > > +		return -EACCES;
> > > +
> > >  	range = to_xe_range(r);
> > > -	if (xe_svm_range_is_valid(range, tile))
> > > +	if (xe_svm_range_is_valid(range, tile, ctx.devmem_only))
> > >  		return 0;
> > >  
> > >  	range_debug(range, "PAGE FAULT");
> > >  
> > > -	/* XXX: Add migration policy, for now migrate range once
> > > */
> > > -	if (!range->skip_migrate && range-
> > > >base.flags.migrate_devmem
> > > &&
> > > -	    xe_svm_range_size(range) >= SZ_64K) {
> > > -		range->skip_migrate = true;
> > > -
> > > +	if (--migrate_try_count >= 0 &&
> > > +	    xe_svm_range_needs_migrate_to_vram(range, vma)) {
> > >  		err = xe_svm_alloc_vram(vm, tile, range, &ctx);
> > >  		if (err) {
> > > -			drm_dbg(&vm->xe->drm,
> > > -				"VRAM allocation failed, falling
> > > back to "
> > > -				"retrying fault, asid=%u,
> > > errno=%pe\n",
> > > -				vm->usm.asid, ERR_PTR(err));
> > > -			goto retry;
> > > +			if (migrate_try_count ||
> > > !ctx.devmem_only) {
> > > +				drm_dbg(&vm->xe->drm,
> > > +					"VRAM allocation failed,
> > > falling back to retrying fault, asid=%u, errno=%pe\n",
> > > +					vm->usm.asid,
> > > ERR_PTR(err));
> > > +				goto retry;
> > > +			} else {
> > > +				drm_err(&vm->xe->drm,
> > > +					"VRAM allocation failed,
> > > retry count exceeded, asid=%u, errno=%pe\n",
> > > +					vm->usm.asid,
> > > ERR_PTR(err));
> > > +				return err;
> > > +			}
> > >  		}
> > >  	}
> > >  
> > > @@ -801,15 +854,22 @@ int xe_svm_handle_pagefault(struct xe_vm
> > > *vm,
> > > struct xe_vma *vma,
> > >  	err = drm_gpusvm_range_get_pages(&vm->svm.gpusvm, r,
> > > &ctx);
> > >  	/* Corner where CPU mappings have changed */
> > >  	if (err == -EOPNOTSUPP || err == -EFAULT || err == -
> > > EPERM) {
> > > -		if (err == -EOPNOTSUPP) {
> > > -			range_debug(range, "PAGE FAULT - EVICT
> > > PAGES");
> > > -			drm_gpusvm_range_evict(&vm->svm.gpusvm,
> > > &range->base);
> > > +		if (migrate_try_count > 0 || !ctx.devmem_only) {
> > > +			if (err == -EOPNOTSUPP) {
> > > +				range_debug(range, "PAGE FAULT -
> > > EVICT PAGES");
> > > +				drm_gpusvm_range_evict(&vm-
> > > > svm.gpusvm,
> > > +						       &range-
> > > > base);
> > > +			}
> > > +			drm_dbg(&vm->xe->drm,
> > > +				"Get pages failed, falling back
> > > to
> > > retrying, asid=%u, gpusvm=%p, errno=%pe\n",
> > > +				vm->usm.asid, &vm->svm.gpusvm,
> > > ERR_PTR(err));
> > > +			range_debug(range, "PAGE FAULT - RETRY
> > > PAGES");
> > > +			goto retry;
> > > +		} else {
> > > +			drm_err(&vm->xe->drm,
> > > +				"Get pages failed, retry count
> > > exceeded, asid=%u, gpusvm=%p, errno=%pe\n",
> > > +				vm->usm.asid, &vm->svm.gpusvm,
> > > ERR_PTR(err));
> > >  		}
> > > -		drm_dbg(&vm->xe->drm,
> > > -			"Get pages failed, falling back to
> > > retrying,
> > > asid=%u, gpusvm=%p, errno=%pe\n",
> > > -			vm->usm.asid, &vm->svm.gpusvm,
> > > ERR_PTR(err));
> > > -		range_debug(range, "PAGE FAULT - RETRY PAGES");
> > > -		goto retry;
> > >  	}
> > >  	if (err) {
> > >  		range_debug(range, "PAGE FAULT - FAIL PAGE
> > > COLLECT");
> > > @@ -843,9 +903,6 @@ int xe_svm_handle_pagefault(struct xe_vm *vm,
> > > struct xe_vma *vma,
> > >  	}
> > >  	drm_exec_fini(&exec);
> > >  
> > > -	if (xe_modparam.always_migrate_to_vram)
> > > -		range->skip_migrate = false;
> > > -
> > >  	dma_fence_wait(fence, false);
> > >  	dma_fence_put(fence);
> > >  
> > > diff --git a/drivers/gpu/drm/xe/xe_svm.h
> > > b/drivers/gpu/drm/xe/xe_svm.h
> > > index 3d441eb1f7ea..0e1f376a7471 100644
> > > --- a/drivers/gpu/drm/xe/xe_svm.h
> > > +++ b/drivers/gpu/drm/xe/xe_svm.h
> > > @@ -39,11 +39,6 @@ struct xe_svm_range {
> > >  	 * range. Protected by GPU SVM notifier lock.
> > >  	 */
> > >  	u8 tile_invalidated;
> > > -	/**
> > > -	 * @skip_migrate: Skip migration to VRAM, protected by
> > > GPU
> > > fault handler
> > > -	 * locking.
> > > -	 */
> > > -	u8 skip_migrate	:1;
> > >  };
> > >  
> > >  /**
> > > diff --git a/include/drm/drm_gpusvm.h b/include/drm/drm_gpusvm.h
> > > index 9fd25fc880a4..653d48dbe1c1 100644
> > > --- a/include/drm/drm_gpusvm.h
> > > +++ b/include/drm/drm_gpusvm.h
> > > @@ -185,6 +185,31 @@ struct drm_gpusvm_notifier {
> > >  	} flags;
> > >  };
> > >  
> > > +/**
> > > + * struct drm_gpusvm_range_flags - Structure representing a GPU
> > > SVM
> > > range flags
> > > + *
> > > + * @migrate_devmem: Flag indicating whether the range can be
> > > migrated to device memory
> > > + * @unmapped: Flag indicating if the range has been unmapped
> > > + * @partial_unmap: Flag indicating if the range has been
> > > partially
> > > unmapped
> > > + * @has_devmem_pages: Flag indicating if the range has devmem
> > > pages
> > > + * @has_dma_mapping: Flag indicating if the range has a DMA
> > > mapping
> > > + * @__flags: Flags for range in u16 form (used for READ_ONCE)
> > > + */
> > > +struct drm_gpusvm_range_flags {
> > > +	union {
> > > +		struct {
> > > +			/* All flags below must be set upon
> > > creation
> > > */
> > > +			u16 migrate_devmem : 1;
> > > +			/* All flags below must be set / cleared
> > > under notifier lock */
> > > +			u16 unmapped : 1;
> > > +			u16 partial_unmap : 1;
> > > +			u16 has_devmem_pages : 1;
> > > +			u16 has_dma_mapping : 1;
> > > +		};
> > > +		u16 __flags;
> > > +	};
> > > +};
> > > +
> > >  /**
> > >   * struct drm_gpusvm_range - Structure representing a GPU SVM
> > > range
> > >   *
> > > @@ -198,11 +223,6 @@ struct drm_gpusvm_notifier {
> > >   * @dpagemap: The struct drm_pagemap of the device pages we're
> > > dma-
> > > mapping.
> > >   *            Note this is assuming only one drm_pagemap per
> > > range
> > > is allowed.
> > >   * @flags: Flags for range
> > > - * @flags.migrate_devmem: Flag indicating whether the range can
> > > be
> > > migrated to device memory
> > > - * @flags.unmapped: Flag indicating if the range has been
> > > unmapped
> > > - * @flags.partial_unmap: Flag indicating if the range has been
> > > partially unmapped
> > > - * @flags.has_devmem_pages: Flag indicating if the range has
> > > devmem
> > > pages
> > > - * @flags.has_dma_mapping: Flag indicating if the range has a
> > > DMA
> > > mapping
> > >   *
> > >   * This structure represents a GPU SVM range used for tracking
> > > memory ranges
> > >   * mapped in a DRM device.
> > > @@ -216,15 +236,7 @@ struct drm_gpusvm_range {
> > >  	unsigned long notifier_seq;
> > >  	struct drm_pagemap_device_addr *dma_addr;
> > >  	struct drm_pagemap *dpagemap;
> > > -	struct {
> > > -		/* All flags below must be set upon creation */
> > > -		u16 migrate_devmem : 1;
> > > -		/* All flags below must be set / cleared under
> > > notifier lock */
> > > -		u16 unmapped : 1;
> > > -		u16 partial_unmap : 1;
> > > -		u16 has_devmem_pages : 1;
> > > -		u16 has_dma_mapping : 1;
> > > -	} flags;
> > > +	struct drm_gpusvm_range_flags flags;
> > >  };
> > >  
> > >  /**
> > 



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