[PATCH v2 1/5] drm/i915: instantiate ttm ranger manager for stolen memory

[PATCH v2 1/5] drm/i915: instantiate ttm ranger manager for stolen memory

[Robert Beckett]

prepare for ttm based stolen region by using ttm range manager
as the resource manager for stolen region.

Signed-off-by: Robert Beckett <bob.beckett@collabora.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c |  6 ++--
 drivers/gpu/drm/i915/intel_region_ttm.c      | 31 +++++++++++++++-----
 2 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
index a10716f4e717..358f8a1a30ce 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
@@ -58,11 +58,13 @@ i915_ttm_region(struct ttm_device *bdev, int ttm_mem_type)
 	struct drm_i915_private *i915 = container_of(bdev, typeof(*i915), bdev);
 
 	/* There's some room for optimization here... */
-	GEM_BUG_ON(ttm_mem_type != I915_PL_SYSTEM &&
-		   ttm_mem_type < I915_PL_LMEM0);
+	GEM_BUG_ON(ttm_mem_type == I915_PL_GGTT);
+
 	if (ttm_mem_type == I915_PL_SYSTEM)
 		return intel_memory_region_lookup(i915, INTEL_MEMORY_SYSTEM,
 						  0);
+	if (ttm_mem_type == I915_PL_STOLEN)
+		return i915->mm.stolen_region;
 
 	return intel_memory_region_lookup(i915, INTEL_MEMORY_LOCAL,
 					  ttm_mem_type - I915_PL_LMEM0);
diff --git a/drivers/gpu/drm/i915/intel_region_ttm.c b/drivers/gpu/drm/i915/intel_region_ttm.c
index 62ff77445b01..7d49ea72e33f 100644
--- a/drivers/gpu/drm/i915/intel_region_ttm.c
+++ b/drivers/gpu/drm/i915/intel_region_ttm.c
@@ -49,7 +49,7 @@ void intel_region_ttm_device_fini(struct drm_i915_private *dev_priv)
 
 /*
  * Map the i915 memory regions to TTM memory types. We use the
- * driver-private types for now, reserving TTM_PL_VRAM for stolen
+ * driver-private types for now, reserving I915_PL_STOLEN for stolen
  * memory and TTM_PL_TT for GGTT use if decided to implement this.
  */
 int intel_region_to_ttm_type(const struct intel_memory_region *mem)
@@ -58,11 +58,17 @@ int intel_region_to_ttm_type(const struct intel_memory_region *mem)
 
 	GEM_BUG_ON(mem->type != INTEL_MEMORY_LOCAL &&
 		   mem->type != INTEL_MEMORY_MOCK &&
-		   mem->type != INTEL_MEMORY_SYSTEM);
+		   mem->type != INTEL_MEMORY_SYSTEM &&
+		   mem->type != INTEL_MEMORY_STOLEN_SYSTEM &&
+		   mem->type != INTEL_MEMORY_STOLEN_LOCAL);
 
 	if (mem->type == INTEL_MEMORY_SYSTEM)
 		return TTM_PL_SYSTEM;
 
+	if (mem->type == INTEL_MEMORY_STOLEN_SYSTEM ||
+	    mem->type == INTEL_MEMORY_STOLEN_LOCAL)
+		return I915_PL_STOLEN;
+
 	type = mem->instance + TTM_PL_PRIV;
 	GEM_BUG_ON(type >= TTM_NUM_MEM_TYPES);
 
@@ -86,10 +92,16 @@ int intel_region_ttm_init(struct intel_memory_region *mem)
 	int mem_type = intel_region_to_ttm_type(mem);
 	int ret;
 
-	ret = i915_ttm_buddy_man_init(bdev, mem_type, false,
-				      resource_size(&mem->region),
-				      mem->io_size,
-				      mem->min_page_size, PAGE_SIZE);
+	if (mem_type == I915_PL_STOLEN) {
+		ret = ttm_range_man_init(bdev, mem_type, false,
+					 resource_size(&mem->region) >> PAGE_SHIFT);
+		mem->is_range_manager = true;
+	} else {
+		ret = i915_ttm_buddy_man_init(bdev, mem_type, false,
+					      resource_size(&mem->region),
+					      mem->io_size,
+					      mem->min_page_size, PAGE_SIZE);
+	}
 	if (ret)
 		return ret;
 
@@ -109,6 +121,7 @@ int intel_region_ttm_init(struct intel_memory_region *mem)
 int intel_region_ttm_fini(struct intel_memory_region *mem)
 {
 	struct ttm_resource_manager *man = mem->region_private;
+	int mem_type = intel_region_to_ttm_type(mem);
 	int ret = -EBUSY;
 	int count;
 
@@ -139,8 +152,10 @@ int intel_region_ttm_fini(struct intel_memory_region *mem)
 	if (ret || !man)
 		return ret;
 
-	ret = i915_ttm_buddy_man_fini(&mem->i915->bdev,
-				      intel_region_to_ttm_type(mem));
+	if (mem_type == I915_PL_STOLEN)
+		ret = ttm_range_man_fini(&mem->i915->bdev, mem_type);
+	else
+		ret = i915_ttm_buddy_man_fini(&mem->i915->bdev, mem_type);
 	GEM_WARN_ON(ret);
 	mem->region_private = NULL;
 
-- 
2.25.1

[PATCH v2 2/5] drm/i915: sanitize mem_flags for stolen buffers

[Robert Beckett]

stolen regions are not page backed or considered iomem.

Signed-off-by: Robert Beckett <bob.beckett@collabora.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
index 358f8a1a30ce..9fe8132de3b2 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
@@ -122,8 +122,9 @@ void i915_ttm_adjust_gem_after_move(struct drm_i915_gem_object *obj)
 
 	obj->mem_flags &= ~(I915_BO_FLAG_STRUCT_PAGE | I915_BO_FLAG_IOMEM);
 
-	obj->mem_flags |= i915_ttm_cpu_maps_iomem(bo->resource) ? I915_BO_FLAG_IOMEM :
-		I915_BO_FLAG_STRUCT_PAGE;
+	if (obj->mm.region->id != INTEL_REGION_STOLEN_SMEM)
+		obj->mem_flags |= i915_ttm_cpu_maps_iomem(bo->resource) ? I915_BO_FLAG_IOMEM :
+			I915_BO_FLAG_STRUCT_PAGE;
 
 	cache_level = i915_ttm_cache_level(to_i915(bo->base.dev), bo->resource,
 					   bo->ttm);
-- 
2.25.1

Re: [PATCH v2 2/5] drm/i915: sanitize mem_flags for stolen buffers

[Thomas Hellström]

On Tue, 2022-04-12 at 15:18 +0000, Robert Beckett wrote:
> stolen regions are not page backed or considered iomem.

thus...

A little more elaborate commit message please.


> 
> Signed-off-by: Robert Beckett <bob.beckett@collabora.com>

Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>


> ---
>  drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
> b/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
> index 358f8a1a30ce..9fe8132de3b2 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
> @@ -122,8 +122,9 @@ void i915_ttm_adjust_gem_after_move(struct
> drm_i915_gem_object *obj)
>  
>         obj->mem_flags &= ~(I915_BO_FLAG_STRUCT_PAGE |
> I915_BO_FLAG_IOMEM);
>  
> -       obj->mem_flags |= i915_ttm_cpu_maps_iomem(bo->resource) ?
> I915_BO_FLAG_IOMEM :
> -               I915_BO_FLAG_STRUCT_PAGE;
> +       if (obj->mm.region->id != INTEL_REGION_STOLEN_SMEM)
> +               obj->mem_flags |= i915_ttm_cpu_maps_iomem(bo-
> >resource) ? I915_BO_FLAG_IOMEM :
> +                       I915_BO_FLAG_STRUCT_PAGE;
>  
>         cache_level = i915_ttm_cache_level(to_i915(bo->base.dev), bo-
> >resource,
>                                            bo->ttm);

[PATCH v2 3/5] drm/i915: ttm move/clear logic fix

[Robert Beckett]

ttm managed buffers start off with system resource definitions and ttm_tt
tracking structures allocated (though unpopulated).
currently this prevents clearing of buffers on first move to desired
placements.

The desired behaviour is to clear user allocated buffers and any kernel
buffers that specifically requests it only.
Make the logic match the desired behaviour.

Signed-off-by: Robert Beckett <bob.beckett@collabora.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c | 22 +++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
index 9fe8132de3b2..9cf85f91edb5 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
@@ -3,6 +3,7 @@
  * Copyright © 2021 Intel Corporation
  */
 
+#include "drm/ttm/ttm_tt.h"
 #include <drm/ttm/ttm_bo_driver.h>
 
 #include "i915_deps.h"
@@ -470,6 +471,25 @@ __i915_ttm_move(struct ttm_buffer_object *bo,
 	return fence;
 }
 
+static bool
+allow_clear(struct drm_i915_gem_object *obj, struct ttm_tt *ttm, struct ttm_resource *dst_mem)
+{
+	/* never clear stolen */
+	if (dst_mem->mem_type == I915_PL_STOLEN)
+		return false;
+	/*
+	 * we want to clear user buffers and any kernel buffers
+	 * that specifically request clearing.
+	 */
+	if (obj->flags & I915_BO_ALLOC_USER)
+		return true;
+
+	if (ttm && ttm->page_flags & TTM_TT_FLAG_ZERO_ALLOC)
+		return true;
+
+	return false;
+}
+
 /**
  * i915_ttm_move - The TTM move callback used by i915.
  * @bo: The buffer object.
@@ -520,7 +540,7 @@ int i915_ttm_move(struct ttm_buffer_object *bo, bool evict,
 		return PTR_ERR(dst_rsgt);
 
 	clear = !i915_ttm_cpu_maps_iomem(bo->resource) && (!ttm || !ttm_tt_is_populated(ttm));
-	if (!(clear && ttm && !(ttm->page_flags & TTM_TT_FLAG_ZERO_ALLOC))) {
+	if (!clear || allow_clear(obj, ttm, dst_mem)) {
 		struct i915_deps deps;
 
 		i915_deps_init(&deps, GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN);
-- 
2.25.1

Re: [PATCH v2 3/5] drm/i915: ttm move/clear logic fix

[Thomas Hellström]

On Tue, 2022-04-12 at 15:18 +0000, Robert Beckett wrote:
> ttm managed buffers start off with system resource definitions and
> ttm_tt
> tracking structures allocated (though unpopulated).
> currently this prevents clearing of buffers on first move to desired
> placements.
> 
> The desired behaviour is to clear user allocated buffers and any
> kernel
> buffers that specifically requests it only.
> Make the logic match the desired behaviour.
> 
> Signed-off-by: Robert Beckett <bob.beckett@collabora.com>

Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>


> ---
>  drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c | 22
> +++++++++++++++++++-
>  1 file changed, 21 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
> b/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
> index 9fe8132de3b2..9cf85f91edb5 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
> @@ -3,6 +3,7 @@
>   * Copyright © 2021 Intel Corporation
>   */
>  
> +#include "drm/ttm/ttm_tt.h"
>  #include <drm/ttm/ttm_bo_driver.h>
>  
>  #include "i915_deps.h"
> @@ -470,6 +471,25 @@ __i915_ttm_move(struct ttm_buffer_object *bo,
>         return fence;
>  }
>  
> +static bool
> +allow_clear(struct drm_i915_gem_object *obj, struct ttm_tt *ttm,
> struct ttm_resource *dst_mem)
> +{
> +       /* never clear stolen */
> +       if (dst_mem->mem_type == I915_PL_STOLEN)
> +               return false;
> +       /*
> +        * we want to clear user buffers and any kernel buffers
> +        * that specifically request clearing.
> +        */
> +       if (obj->flags & I915_BO_ALLOC_USER)
> +               return true;
> +
> +       if (ttm && ttm->page_flags & TTM_TT_FLAG_ZERO_ALLOC)
> +               return true;
> +
> +       return false;
> +}
> +
>  /**
>   * i915_ttm_move - The TTM move callback used by i915.
>   * @bo: The buffer object.
> @@ -520,7 +540,7 @@ int i915_ttm_move(struct ttm_buffer_object *bo,
> bool evict,
>                 return PTR_ERR(dst_rsgt);
>  
>         clear = !i915_ttm_cpu_maps_iomem(bo->resource) && (!ttm ||
> !ttm_tt_is_populated(ttm));
> -       if (!(clear && ttm && !(ttm->page_flags &
> TTM_TT_FLAG_ZERO_ALLOC))) {
> +       if (!clear || allow_clear(obj, ttm, dst_mem)) {
>                 struct i915_deps deps;
>  
>                 i915_deps_init(&deps, GFP_KERNEL | __GFP_NORETRY |
> __GFP_NOWARN);

[PATCH v2 4/5] drm/i915: ttm backend dont provide mmap_offset for kernel buffers

[Robert Beckett]

stolen/kernel buffers should not be mmapable by userland.
do not provide callbacks to facilitate this for these buffers.

Signed-off-by: Robert Beckett <bob.beckett@collabora.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 32 +++++++++++++++++++++----
 1 file changed, 27 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
index a878910a563c..b20f81836c54 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
@@ -1092,8 +1092,8 @@ static void i915_ttm_unmap_virtual(struct drm_i915_gem_object *obj)
 	ttm_bo_unmap_virtual(i915_gem_to_ttm(obj));
 }
 
-static const struct drm_i915_gem_object_ops i915_gem_ttm_obj_ops = {
-	.name = "i915_gem_object_ttm",
+static const struct drm_i915_gem_object_ops i915_gem_ttm_user_obj_ops = {
+	.name = "i915_gem_object_ttm_user",
 	.flags = I915_GEM_OBJECT_IS_SHRINKABLE |
 		 I915_GEM_OBJECT_SELF_MANAGED_SHRINK_LIST,
 
@@ -1111,6 +1111,21 @@ static const struct drm_i915_gem_object_ops i915_gem_ttm_obj_ops = {
 	.mmap_ops = &vm_ops_ttm,
 };
 
+static const struct drm_i915_gem_object_ops i915_gem_ttm_kern_obj_ops = {
+	.name = "i915_gem_object_ttm_kern",
+	.flags = I915_GEM_OBJECT_IS_SHRINKABLE |
+		 I915_GEM_OBJECT_SELF_MANAGED_SHRINK_LIST,
+
+	.get_pages = i915_ttm_get_pages,
+	.put_pages = i915_ttm_put_pages,
+	.truncate = i915_ttm_truncate,
+	.shrink = i915_ttm_shrink,
+
+	.adjust_lru = i915_ttm_adjust_lru,
+	.delayed_free = i915_ttm_delayed_free,
+	.migrate = i915_ttm_migrate,
+};
+
 void i915_ttm_bo_destroy(struct ttm_buffer_object *bo)
 {
 	struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
@@ -1165,10 +1180,19 @@ int __i915_gem_ttm_object_init(struct intel_memory_region *mem,
 		.no_wait_gpu = false,
 	};
 	enum ttm_bo_type bo_type;
+	const struct drm_i915_gem_object_ops *ops;
 	int ret;
 
 	drm_gem_private_object_init(&i915->drm, &obj->base, size);
-	i915_gem_object_init(obj, &i915_gem_ttm_obj_ops, &lock_class, flags);
+
+	if (flags & I915_BO_ALLOC_USER && intel_region_to_ttm_type(mem) != I915_PL_STOLEN) {
+		bo_type = ttm_bo_type_device;
+		ops = &i915_gem_ttm_user_obj_ops;
+	} else {
+		bo_type = ttm_bo_type_kernel;
+		ops = &i915_gem_ttm_kern_obj_ops;
+	}
+	i915_gem_object_init(obj, ops, &lock_class, flags);
 
 	obj->bo_offset = offset;
 
@@ -1178,8 +1202,6 @@ int __i915_gem_ttm_object_init(struct intel_memory_region *mem,
 
 	INIT_RADIX_TREE(&obj->ttm.get_io_page.radix, GFP_KERNEL | __GFP_NOWARN);
 	mutex_init(&obj->ttm.get_io_page.lock);
-	bo_type = (obj->flags & I915_BO_ALLOC_USER) ? ttm_bo_type_device :
-		ttm_bo_type_kernel;
 
 	obj->base.vma_node.driver_private = i915_gem_to_ttm(obj);
 
-- 
2.25.1

Re: [PATCH v2 4/5] drm/i915: ttm backend dont provide mmap_offset for kernel buffers

[Thomas Hellström]

On Tue, 2022-04-12 at 15:18 +0000, Robert Beckett wrote:
> stolen/kernel buffers should not be mmapable by userland.
> do not provide callbacks to facilitate this for these buffers.
> 
> Signed-off-by: Robert Beckett <bob.beckett@collabora.com>
> ---
>  drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 32 +++++++++++++++++++++--
> --
>  1 file changed, 27 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> index a878910a563c..b20f81836c54 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> @@ -1092,8 +1092,8 @@ static void i915_ttm_unmap_virtual(struct
> drm_i915_gem_object *obj)
>         ttm_bo_unmap_virtual(i915_gem_to_ttm(obj));
>  }
>  
> -static const struct drm_i915_gem_object_ops i915_gem_ttm_obj_ops = {
> -       .name = "i915_gem_object_ttm",
> +static const struct drm_i915_gem_object_ops
> i915_gem_ttm_user_obj_ops = {
> +       .name = "i915_gem_object_ttm_user",
>         .flags = I915_GEM_OBJECT_IS_SHRINKABLE |
>                  I915_GEM_OBJECT_SELF_MANAGED_SHRINK_LIST,
>  
> @@ -1111,6 +1111,21 @@ static const struct drm_i915_gem_object_ops
> i915_gem_ttm_obj_ops = {
>         .mmap_ops = &vm_ops_ttm,
>  };
>  
> +static const struct drm_i915_gem_object_ops
> i915_gem_ttm_kern_obj_ops = {
> +       .name = "i915_gem_object_ttm_kern",
> +       .flags = I915_GEM_OBJECT_IS_SHRINKABLE |
> +                I915_GEM_OBJECT_SELF_MANAGED_SHRINK_LIST,
> +
> +       .get_pages = i915_ttm_get_pages,
> +       .put_pages = i915_ttm_put_pages,
> +       .truncate = i915_ttm_truncate,
> +       .shrink = i915_ttm_shrink,
> +
> +       .adjust_lru = i915_ttm_adjust_lru,
> +       .delayed_free = i915_ttm_delayed_free,
> +       .migrate = i915_ttm_migrate,
> +};

Do we really need two different ops here?

Since if we don't have mmap ops, basically that tells GEM it should do
the mmapping rather than TTM. 

That might of course come in handy for the shmem backend, but I don't
fully follow why we need this for stolen.

Also for the framebuffer handed over from BIOS to fbdev, Does that need
mmapping and if so, how do we handle that?


/Thomas




> +
>  void i915_ttm_bo_destroy(struct ttm_buffer_object *bo)
>  {
>         struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
> @@ -1165,10 +1180,19 @@ int __i915_gem_ttm_object_init(struct
> intel_memory_region *mem,
>                 .no_wait_gpu = false,
>         };
>         enum ttm_bo_type bo_type;
> +       const struct drm_i915_gem_object_ops *ops;
>         int ret;
>  
>         drm_gem_private_object_init(&i915->drm, &obj->base, size);
> -       i915_gem_object_init(obj, &i915_gem_ttm_obj_ops, &lock_class,
> flags);
> +
> +       if (flags & I915_BO_ALLOC_USER &&
> intel_region_to_ttm_type(mem) != I915_PL_STOLEN) {
> +               bo_type = ttm_bo_type_device;
> +               ops = &i915_gem_ttm_user_obj_ops;
> +       } else {
> +               bo_type = ttm_bo_type_kernel;
> +               ops = &i915_gem_ttm_kern_obj_ops;
> +       }
> +       i915_gem_object_init(obj, ops, &lock_class, flags);
>  
>         obj->bo_offset = offset;
>  
> @@ -1178,8 +1202,6 @@ int __i915_gem_ttm_object_init(struct
> intel_memory_region *mem,
>  
>         INIT_RADIX_TREE(&obj->ttm.get_io_page.radix, GFP_KERNEL |
> __GFP_NOWARN);
>         mutex_init(&obj->ttm.get_io_page.lock);
> -       bo_type = (obj->flags & I915_BO_ALLOC_USER) ?
> ttm_bo_type_device :
> -               ttm_bo_type_kernel;
>  
>         obj->base.vma_node.driver_private = i915_gem_to_ttm(obj);
>  

Re: [PATCH v2 4/5] drm/i915: ttm backend dont provide mmap_offset for kernel buffers

[Robert Beckett]

On 14/04/2022 15:05, Thomas Hellström wrote:
> On Tue, 2022-04-12 at 15:18 +0000, Robert Beckett wrote:
>> stolen/kernel buffers should not be mmapable by userland.
>> do not provide callbacks to facilitate this for these buffers.
>>
>> Signed-off-by: Robert Beckett <bob.beckett@collabora.com>
>> ---
>>   drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 32 +++++++++++++++++++++--
>> --
>>   1 file changed, 27 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
>> b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
>> index a878910a563c..b20f81836c54 100644
>> --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
>> @@ -1092,8 +1092,8 @@ static void i915_ttm_unmap_virtual(struct
>> drm_i915_gem_object *obj)
>>          ttm_bo_unmap_virtual(i915_gem_to_ttm(obj));
>>   }
>>   
>> -static const struct drm_i915_gem_object_ops i915_gem_ttm_obj_ops = {
>> -       .name = "i915_gem_object_ttm",
>> +static const struct drm_i915_gem_object_ops
>> i915_gem_ttm_user_obj_ops = {
>> +       .name = "i915_gem_object_ttm_user",
>>          .flags = I915_GEM_OBJECT_IS_SHRINKABLE |
>>                   I915_GEM_OBJECT_SELF_MANAGED_SHRINK_LIST,
>>   
>> @@ -1111,6 +1111,21 @@ static const struct drm_i915_gem_object_ops
>> i915_gem_ttm_obj_ops = {
>>          .mmap_ops = &vm_ops_ttm,
>>   };
>>   
>> +static const struct drm_i915_gem_object_ops
>> i915_gem_ttm_kern_obj_ops = {
>> +       .name = "i915_gem_object_ttm_kern",
>> +       .flags = I915_GEM_OBJECT_IS_SHRINKABLE |
>> +                I915_GEM_OBJECT_SELF_MANAGED_SHRINK_LIST,
>> +
>> +       .get_pages = i915_ttm_get_pages,
>> +       .put_pages = i915_ttm_put_pages,
>> +       .truncate = i915_ttm_truncate,
>> +       .shrink = i915_ttm_shrink,
>> +
>> +       .adjust_lru = i915_ttm_adjust_lru,
>> +       .delayed_free = i915_ttm_delayed_free,
>> +       .migrate = i915_ttm_migrate,
>> +};
> 
> Do we really need two different ops here?
> 
> Since if we don't have mmap ops, basically that tells GEM it should do
> the mmapping rather than TTM.
> 
> That might of course come in handy for the shmem backend, but I don't
> fully follow why we need this for stolen.

the main rationale for doing this was to avoid 
drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c:can_mmap() presuming 
that is can use I915_MMAP_TYPE_FIXED

As the original backend also did not have mmap_offset handlers for 
stolen, this seemed like a reasonable design.

If desired, we could add a special case for the testing logic, but those 
special cases have tendency to multiply.

> 
> Also for the framebuffer handed over from BIOS to fbdev, Does that need
> mmapping and if so, how do we handle that?
> 

I'm not sure of the usecase there. Do you know of any igt test that 
tests this? I can investigate further if you do not.

> 
> /Thomas
> 
> 
> 
> 
>> +
>>   void i915_ttm_bo_destroy(struct ttm_buffer_object *bo)
>>   {
>>          struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
>> @@ -1165,10 +1180,19 @@ int __i915_gem_ttm_object_init(struct
>> intel_memory_region *mem,
>>                  .no_wait_gpu = false,
>>          };
>>          enum ttm_bo_type bo_type;
>> +       const struct drm_i915_gem_object_ops *ops;
>>          int ret;
>>   
>>          drm_gem_private_object_init(&i915->drm, &obj->base, size);
>> -       i915_gem_object_init(obj, &i915_gem_ttm_obj_ops, &lock_class,
>> flags);
>> +
>> +       if (flags & I915_BO_ALLOC_USER &&
>> intel_region_to_ttm_type(mem) != I915_PL_STOLEN) {
>> +               bo_type = ttm_bo_type_device;
>> +               ops = &i915_gem_ttm_user_obj_ops;
>> +       } else {
>> +               bo_type = ttm_bo_type_kernel;
>> +               ops = &i915_gem_ttm_kern_obj_ops;
>> +       }
>> +       i915_gem_object_init(obj, ops, &lock_class, flags);
>>   
>>          obj->bo_offset = offset;
>>   
>> @@ -1178,8 +1202,6 @@ int __i915_gem_ttm_object_init(struct
>> intel_memory_region *mem,
>>   
>>          INIT_RADIX_TREE(&obj->ttm.get_io_page.radix, GFP_KERNEL |
>> __GFP_NOWARN);
>>          mutex_init(&obj->ttm.get_io_page.lock);
>> -       bo_type = (obj->flags & I915_BO_ALLOC_USER) ?
>> ttm_bo_type_device :
>> -               ttm_bo_type_kernel;
>>   
>>          obj->base.vma_node.driver_private = i915_gem_to_ttm(obj);
>>   
> 
> 

Re: [PATCH v2 4/5] drm/i915: ttm backend dont provide mmap_offset for kernel buffers

[Thomas Hellström]

Sorry for late reply,

On Thu, 2022-04-14 at 17:13 +0100, Robert Beckett wrote:
> 
> 
> On 14/04/2022 15:05, Thomas Hellström wrote:
> > On Tue, 2022-04-12 at 15:18 +0000, Robert Beckett wrote:
> > > stolen/kernel buffers should not be mmapable by userland.
> > > do not provide callbacks to facilitate this for these buffers.
> > > 
> > > Signed-off-by: Robert Beckett <bob.beckett@collabora.com>
> > > ---
> > >   drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 32
> > > +++++++++++++++++++++--
> > > --
> > >   1 file changed, 27 insertions(+), 5 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> > > b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> > > index a878910a563c..b20f81836c54 100644
> > > --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> > > +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> > > @@ -1092,8 +1092,8 @@ static void i915_ttm_unmap_virtual(struct
> > > drm_i915_gem_object *obj)
> > >          ttm_bo_unmap_virtual(i915_gem_to_ttm(obj));
> > >   }
> > >   
> > > -static const struct drm_i915_gem_object_ops i915_gem_ttm_obj_ops
> > > = {
> > > -       .name = "i915_gem_object_ttm",
> > > +static const struct drm_i915_gem_object_ops
> > > i915_gem_ttm_user_obj_ops = {
> > > +       .name = "i915_gem_object_ttm_user",
> > >          .flags = I915_GEM_OBJECT_IS_SHRINKABLE |
> > >                   I915_GEM_OBJECT_SELF_MANAGED_SHRINK_LIST,
> > >   
> > > @@ -1111,6 +1111,21 @@ static const struct
> > > drm_i915_gem_object_ops
> > > i915_gem_ttm_obj_ops = {
> > >          .mmap_ops = &vm_ops_ttm,
> > >   };
> > >   
> > > +static const struct drm_i915_gem_object_ops
> > > i915_gem_ttm_kern_obj_ops = {
> > > +       .name = "i915_gem_object_ttm_kern",
> > > +       .flags = I915_GEM_OBJECT_IS_SHRINKABLE |
> > > +                I915_GEM_OBJECT_SELF_MANAGED_SHRINK_LIST,
> > > +
> > > +       .get_pages = i915_ttm_get_pages,
> > > +       .put_pages = i915_ttm_put_pages,
> > > +       .truncate = i915_ttm_truncate,
> > > +       .shrink = i915_ttm_shrink,
> > > +
> > > +       .adjust_lru = i915_ttm_adjust_lru,
> > > +       .delayed_free = i915_ttm_delayed_free,
> > > +       .migrate = i915_ttm_migrate,
> > > +};
> > 
> > Do we really need two different ops here?
> > 
> > Since if we don't have mmap ops, basically that tells GEM it should
> > do
> > the mmapping rather than TTM.
> > 
> > That might of course come in handy for the shmem backend, but I
> > don't
> > fully follow why we need this for stolen.
> 
> the main rationale for doing this was to avoid 
> drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c:can_mmap()
> presuming 
> that is can use I915_MMAP_TYPE_FIXED
> 
> As the original backend also did not have mmap_offset handlers for 
> stolen, this seemed like a reasonable design.
> 
> If desired, we could add a special case for the testing logic, but
> those 
> special cases have tendency to multiply.
> 
> > 
> > Also for the framebuffer handed over from BIOS to fbdev, Does that
> > need
> > mmapping and if so, how do we handle that?
> > 
> 
> I'm not sure of the usecase there. Do you know of any igt test that 
> tests this? I can investigate further if you do not.

It would be if we the fbdev driver at startup inherits some image that
bios has preloaded into stolen, and then a client tries to write into
it. Not sure that this is a real use case though, or whether, in that
case, that takes a separate path for user-space mappings.

/Thomas



> 
> > 
> > /Thomas
> > 
> > 
> > 
> > 
> > > +
> > >   void i915_ttm_bo_destroy(struct ttm_buffer_object *bo)
> > >   {
> > >          struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
> > > @@ -1165,10 +1180,19 @@ int __i915_gem_ttm_object_init(struct
> > > intel_memory_region *mem,
> > >                  .no_wait_gpu = false,
> > >          };
> > >          enum ttm_bo_type bo_type;
> > > +       const struct drm_i915_gem_object_ops *ops;
> > >          int ret;
> > >   
> > >          drm_gem_private_object_init(&i915->drm, &obj->base,
> > > size);
> > > -       i915_gem_object_init(obj, &i915_gem_ttm_obj_ops,
> > > &lock_class,
> > > flags);
> > > +
> > > +       if (flags & I915_BO_ALLOC_USER &&
> > > intel_region_to_ttm_type(mem) != I915_PL_STOLEN) {
> > > +               bo_type = ttm_bo_type_device;
> > > +               ops = &i915_gem_ttm_user_obj_ops;
> > > +       } else {
> > > +               bo_type = ttm_bo_type_kernel;
> > > +               ops = &i915_gem_ttm_kern_obj_ops;
> > > +       }
> > > +       i915_gem_object_init(obj, ops, &lock_class, flags);
> > >   
> > >          obj->bo_offset = offset;
> > >   
> > > @@ -1178,8 +1202,6 @@ int __i915_gem_ttm_object_init(struct
> > > intel_memory_region *mem,
> > >   
> > >          INIT_RADIX_TREE(&obj->ttm.get_io_page.radix, GFP_KERNEL
> > > |
> > > __GFP_NOWARN);
> > >          mutex_init(&obj->ttm.get_io_page.lock);
> > > -       bo_type = (obj->flags & I915_BO_ALLOC_USER) ?
> > > ttm_bo_type_device :
> > > -               ttm_bo_type_kernel;
> > >   
> > >          obj->base.vma_node.driver_private =
> > > i915_gem_to_ttm(obj);
> > >   
> > 
> > 

[PATCH v2 5/5] drm/i915: stolen memory use ttm backend

[Robert Beckett]

refactor stolen memory region to use ttm.
this necessitates using ttm resources to track reserved stolen regions
instead of drm_mm_nodes.

Signed-off-by: Robert Beckett <bob.beckett@collabora.com>
---
 drivers/gpu/drm/i915/display/intel_fbc.c      |  78 ++--
 .../gpu/drm/i915/gem/i915_gem_object_types.h  |   2 -
 drivers/gpu/drm/i915/gem/i915_gem_stolen.c    | 407 ++++++------------
 drivers/gpu/drm/i915/gem/i915_gem_stolen.h    |  21 +-
 drivers/gpu/drm/i915/gem/i915_gem_ttm.h       |   7 +
 drivers/gpu/drm/i915/gt/intel_rc6.c           |   4 +-
 drivers/gpu/drm/i915/gt/selftest_reset.c      |  16 +-
 drivers/gpu/drm/i915/i915_debugfs.c           |   7 +-
 drivers/gpu/drm/i915/i915_drv.h               |   5 -
 drivers/gpu/drm/i915/intel_region_ttm.c       |  36 +-
 drivers/gpu/drm/i915/intel_region_ttm.h       |   8 +-
 drivers/gpu/drm/i915/selftests/mock_region.c  |   3 +-
 12 files changed, 241 insertions(+), 353 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_fbc.c b/drivers/gpu/drm/i915/display/intel_fbc.c
index b653f3ba7c66..dbad1b6471b8 100644
--- a/drivers/gpu/drm/i915/display/intel_fbc.c
+++ b/drivers/gpu/drm/i915/display/intel_fbc.c
@@ -38,6 +38,7 @@
  * forcibly disable it to allow proper screen updates.
  */
 
+#include "gem/i915_gem_stolen.h"
 #include <linux/string_helpers.h>
 
 #include <drm/drm_fourcc.h>
@@ -51,6 +52,7 @@
 #include "intel_display_types.h"
 #include "intel_fbc.h"
 #include "intel_frontbuffer.h"
+#include "gem/i915_gem_region.h"
 
 #define for_each_fbc_id(__dev_priv, __fbc_id) \
 	for ((__fbc_id) = INTEL_FBC_A; (__fbc_id) < I915_MAX_FBCS; (__fbc_id)++) \
@@ -93,8 +95,8 @@ struct intel_fbc {
 	unsigned int possible_framebuffer_bits;
 	unsigned int busy_bits;
 
-	struct drm_mm_node compressed_fb;
-	struct drm_mm_node compressed_llb;
+	struct ttm_resource *compressed_fb;
+	struct ttm_resource *compressed_llb;
 
 	enum intel_fbc_id id;
 
@@ -332,16 +334,20 @@ static void i8xx_fbc_nuke(struct intel_fbc *fbc)
 static void i8xx_fbc_program_cfb(struct intel_fbc *fbc)
 {
 	struct drm_i915_private *i915 = fbc->i915;
+	u64 fb_offset = i915_gem_stolen_reserve_offset(fbc->compressed_fb);
+	u64 llb_offset = i915_gem_stolen_reserve_offset(fbc->compressed_llb);
 
+	GEM_BUG_ON(fb_offset == I915_BO_INVALID_OFFSET);
+	GEM_BUG_ON(llb_offset == I915_BO_INVALID_OFFSET);
 	GEM_BUG_ON(range_overflows_end_t(u64, i915->dsm.start,
-					 fbc->compressed_fb.start, U32_MAX));
+					 fb_offset, U32_MAX));
 	GEM_BUG_ON(range_overflows_end_t(u64, i915->dsm.start,
-					 fbc->compressed_llb.start, U32_MAX));
+					 llb_offset, U32_MAX));
 
 	intel_de_write(i915, FBC_CFB_BASE,
-		       i915->dsm.start + fbc->compressed_fb.start);
+		       i915->dsm.start + fb_offset);
 	intel_de_write(i915, FBC_LL_BASE,
-		       i915->dsm.start + fbc->compressed_llb.start);
+		       i915->dsm.start + llb_offset);
 }
 
 static const struct intel_fbc_funcs i8xx_fbc_funcs = {
@@ -449,8 +455,10 @@ static bool g4x_fbc_is_compressing(struct intel_fbc *fbc)
 static void g4x_fbc_program_cfb(struct intel_fbc *fbc)
 {
 	struct drm_i915_private *i915 = fbc->i915;
+	u64 fb_offset = i915_gem_stolen_reserve_offset(fbc->compressed_fb);
 
-	intel_de_write(i915, DPFC_CB_BASE, fbc->compressed_fb.start);
+	GEM_BUG_ON(fb_offset == I915_BO_INVALID_OFFSET);
+	intel_de_write(i915, DPFC_CB_BASE, fb_offset);
 }
 
 static const struct intel_fbc_funcs g4x_fbc_funcs = {
@@ -500,8 +508,10 @@ static bool ilk_fbc_is_compressing(struct intel_fbc *fbc)
 static void ilk_fbc_program_cfb(struct intel_fbc *fbc)
 {
 	struct drm_i915_private *i915 = fbc->i915;
+	u64 fb_offset = i915_gem_stolen_reserve_offset(fbc->compressed_fb);
 
-	intel_de_write(i915, ILK_DPFC_CB_BASE(fbc->id), fbc->compressed_fb.start);
+	GEM_BUG_ON(fb_offset == I915_BO_INVALID_OFFSET);
+	intel_de_write(i915, ILK_DPFC_CB_BASE(fbc->id), fb_offset);
 }
 
 static const struct intel_fbc_funcs ilk_fbc_funcs = {
@@ -741,21 +751,24 @@ static int find_compression_limit(struct intel_fbc *fbc,
 {
 	struct drm_i915_private *i915 = fbc->i915;
 	u64 end = intel_fbc_stolen_end(i915);
-	int ret, limit = min_limit;
+	int limit = min_limit;
+	struct ttm_resource *res;
 
 	size /= limit;
 
 	/* Try to over-allocate to reduce reallocations and fragmentation. */
-	ret = i915_gem_stolen_insert_node_in_range(i915, &fbc->compressed_fb,
-						   size <<= 1, 4096, 0, end);
-	if (ret == 0)
+	res = i915_gem_stolen_reserve_range(i915, size <<= 1, 0, end);
+	if (!IS_ERR(res)) {
+		fbc->compressed_fb = res;
 		return limit;
+	}
 
 	for (; limit <= intel_fbc_max_limit(i915); limit <<= 1) {
-		ret = i915_gem_stolen_insert_node_in_range(i915, &fbc->compressed_fb,
-							   size >>= 1, 4096, 0, end);
-		if (ret == 0)
+		res = i915_gem_stolen_reserve_range(i915, size >>= 1, 0, end);
+		if (!IS_ERR(res)) {
+			fbc->compressed_fb = res;
 			return limit;
+		}
 	}
 
 	return 0;
@@ -766,17 +779,18 @@ static int intel_fbc_alloc_cfb(struct intel_fbc *fbc,
 {
 	struct drm_i915_private *i915 = fbc->i915;
 	int ret;
+	struct ttm_resource *res;
 
-	drm_WARN_ON(&i915->drm,
-		    drm_mm_node_allocated(&fbc->compressed_fb));
-	drm_WARN_ON(&i915->drm,
-		    drm_mm_node_allocated(&fbc->compressed_llb));
+	drm_WARN_ON(&i915->drm, fbc->compressed_fb);
+	drm_WARN_ON(&i915->drm, fbc->compressed_llb);
 
 	if (DISPLAY_VER(i915) < 5 && !IS_G4X(i915)) {
-		ret = i915_gem_stolen_insert_node(i915, &fbc->compressed_llb,
-						  4096, 4096);
-		if (ret)
+		res = i915_gem_stolen_reserve_range(i915, 4096, I915_GEM_STOLEN_BIAS, 0);
+		if (IS_ERR(res)) {
+			ret = PTR_ERR(res);
 			goto err;
+		}
+		fbc->compressed_llb = res;
 	}
 
 	ret = find_compression_limit(fbc, size, min_limit);
@@ -790,15 +804,14 @@ static int intel_fbc_alloc_cfb(struct intel_fbc *fbc,
 
 	drm_dbg_kms(&i915->drm,
 		    "reserved %llu bytes of contiguous stolen space for FBC, limit: %d\n",
-		    fbc->compressed_fb.size, fbc->limit);
+		    i915_gem_stolen_reserve_size(fbc->compressed_fb), fbc->limit);
 
 	return 0;
 
 err_llb:
-	if (drm_mm_node_allocated(&fbc->compressed_llb))
-		i915_gem_stolen_remove_node(i915, &fbc->compressed_llb);
+	i915_gem_stolen_release_range(i915, fetch_and_zero(&fbc->compressed_llb));
 err:
-	if (drm_mm_initialized(&i915->mm.stolen))
+	if (IS_ERR(res) && (PTR_ERR(res) == -ENOMEM || PTR_ERR(res) == -ENXIO))
 		drm_info_once(&i915->drm, "not enough stolen space for compressed buffer (need %d more bytes), disabling. Hint: you may be able to increase stolen memory size in the BIOS to avoid this.\n", size);
 	return -ENOSPC;
 }
@@ -815,10 +828,10 @@ static void __intel_fbc_cleanup_cfb(struct intel_fbc *fbc)
 	if (WARN_ON(intel_fbc_hw_is_active(fbc)))
 		return;
 
-	if (drm_mm_node_allocated(&fbc->compressed_llb))
-		i915_gem_stolen_remove_node(i915, &fbc->compressed_llb);
-	if (drm_mm_node_allocated(&fbc->compressed_fb))
-		i915_gem_stolen_remove_node(i915, &fbc->compressed_fb);
+	if (fbc->compressed_llb)
+		i915_gem_stolen_release_range(i915, fetch_and_zero(&fbc->compressed_llb));
+	if (fbc->compressed_fb)
+		i915_gem_stolen_release_range(i915, fetch_and_zero(&fbc->compressed_fb));
 }
 
 void intel_fbc_cleanup(struct drm_i915_private *i915)
@@ -1022,9 +1035,10 @@ static bool intel_fbc_is_cfb_ok(const struct intel_plane_state *plane_state)
 {
 	struct intel_plane *plane = to_intel_plane(plane_state->uapi.plane);
 	struct intel_fbc *fbc = plane->fbc;
+	u64 fb_size = i915_gem_stolen_reserve_size(fbc->compressed_fb);
 
 	return intel_fbc_min_limit(plane_state) <= fbc->limit &&
-		intel_fbc_cfb_size(plane_state) <= fbc->compressed_fb.size * fbc->limit;
+		intel_fbc_cfb_size(plane_state) <= fb_size * fbc->limit;
 }
 
 static bool intel_fbc_is_ok(const struct intel_plane_state *plane_state)
@@ -1703,7 +1717,7 @@ void intel_fbc_init(struct drm_i915_private *i915)
 {
 	enum intel_fbc_id fbc_id;
 
-	if (!drm_mm_initialized(&i915->mm.stolen))
+	if (!i915->mm.stolen_region)
 		mkwrite_device_info(i915)->display.fbc_mask = 0;
 
 	if (need_fbc_vtd_wa(i915))
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
index 2c88bdb8ff7c..492600907e99 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
@@ -629,8 +629,6 @@ struct drm_i915_gem_object {
 		} userptr;
 #endif
 
-		struct drm_mm_node *stolen;
-
 		resource_size_t bo_offset;
 
 		unsigned long scratch;
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
index 47b5e0e342ab..2885c9e962f9 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
@@ -4,75 +4,101 @@
  * Copyright © 2008-2012 Intel Corporation
  */
 
+#include "drm/ttm/ttm_placement.h"
+#include "gem/i915_gem_object_types.h"
 #include <linux/errno.h>
 #include <linux/mutex.h>
 
-#include <drm/drm_mm.h>
 #include <drm/i915_drm.h>
 
 #include "gem/i915_gem_lmem.h"
 #include "gem/i915_gem_region.h"
 #include "gt/intel_gt.h"
 #include "gt/intel_region_lmem.h"
+#include "gem/i915_gem_ttm.h"
 #include "i915_drv.h"
 #include "i915_gem_stolen.h"
 #include "i915_reg.h"
 #include "i915_utils.h"
 #include "i915_vgpu.h"
 #include "intel_mchbar_regs.h"
-
-/*
- * The BIOS typically reserves some of the system's memory for the exclusive
- * use of the integrated graphics. This memory is no longer available for
- * use by the OS and so the user finds that his system has less memory
- * available than he put in. We refer to this memory as stolen.
+#include "intel_region_ttm.h"
+
+/**
+ * i915_gem_stolen_reserve_range - reserve a region of space in a given range
+ * @i915: i915 device instance
+ * @size: size of region to reserve
+ * @start: start of search area
+ * @end: end of search area
  *
- * The BIOS will allocate its framebuffer from the stolen memory. Our
- * goal is try to reuse that object for our own fbcon which must always
- * be available for panics. Anything else we can reuse the stolen memory
- * for is a boon.
+ * Search for @size amount of free space within the region delimeted by @start and @end.
+ * If found reserve it from future use until later release with @i915_gem_stolen_release_range.
+ *
+ * Return: pointer to resource tracking structure on success, ERR_PTR otherwise
  */
-
-int i915_gem_stolen_insert_node_in_range(struct drm_i915_private *i915,
-					 struct drm_mm_node *node, u64 size,
-					 unsigned alignment, u64 start, u64 end)
+struct ttm_resource *
+i915_gem_stolen_reserve_range(struct drm_i915_private *i915,
+			      resource_size_t size,
+			      u64 start, u64 end)
 {
-	int ret;
+	struct intel_memory_region *mem = i915->mm.stolen_region;
 
-	if (!drm_mm_initialized(&i915->mm.stolen))
-		return -ENODEV;
-
-	/* WaSkipStolenMemoryFirstPage:bdw+ */
-	if (GRAPHICS_VER(i915) >= 8 && start < 4096)
-		start = 4096;
-
-	mutex_lock(&i915->mm.stolen_lock);
-	ret = drm_mm_insert_node_in_range(&i915->mm.stolen, node,
-					  size, alignment, 0,
-					  start, end, DRM_MM_INSERT_BEST);
-	mutex_unlock(&i915->mm.stolen_lock);
+	if (!mem)
+		return ERR_PTR(-ENODEV);
+	return intel_region_ttm_resource_alloc(mem, size, start, end, I915_BO_ALLOC_CONTIGUOUS);
+}
 
-	return ret;
+/**
+ * i915_gem_stolen_reserve_offset - return the offset of the reserved space
+ * @res: pointer to resource tracking structure to check
+ *
+ * Return: The offset of the reserved resource, or I915_BO_INVALID_OFFSET on error
+ */
+u64 i915_gem_stolen_reserve_offset(struct ttm_resource *res)
+{
+	if (!res)
+		return I915_BO_INVALID_OFFSET;
+	return PFN_PHYS(res->start);
 }
 
-int i915_gem_stolen_insert_node(struct drm_i915_private *i915,
-				struct drm_mm_node *node, u64 size,
-				unsigned alignment)
+/**
+ * i915_gem_stolen_reserve_size - return the reserved size of the reserved space
+ * @res: pointer to resource tracking structure to check
+ *
+ * Return: The size of the reserved resource, or I915_BO_INVALID_OFFSET on error
+ */
+u64 i915_gem_stolen_reserve_size(struct ttm_resource *res)
 {
-	return i915_gem_stolen_insert_node_in_range(i915, node,
-						    size, alignment,
-						    I915_GEM_STOLEN_BIAS,
-						    U64_MAX);
+	if (!res)
+		return I915_BO_INVALID_OFFSET;
+	return PFN_PHYS(res->num_pages);
 }
 
-void i915_gem_stolen_remove_node(struct drm_i915_private *i915,
-				 struct drm_mm_node *node)
+/**
+ * i915_gem_stolen_release_range - release the reserved area to be free for allocation again
+ * @i915: i915 device instance
+ * @res: pointer to resource tracking structure allocated via @i915_gem_stolen_reserve_range
+ */
+void i915_gem_stolen_release_range(struct drm_i915_private *i915,
+				   struct ttm_resource *res)
 {
-	mutex_lock(&i915->mm.stolen_lock);
-	drm_mm_remove_node(node);
-	mutex_unlock(&i915->mm.stolen_lock);
+	struct intel_memory_region *mem = i915->mm.stolen_region;
+
+	intel_region_ttm_resource_free(mem, res);
 }
 
+/*
+ * The BIOS typically reserves some of the system's memory for the exclusive
+ * use of the integrated graphics. This memory is no longer available for
+ * use by the OS and so the user finds that his system has less memory
+ * available than he put in. We refer to this memory as stolen.
+ *
+ * The BIOS will allocate its framebuffer from the stolen memory. Our
+ * goal is try to reuse that object for our own fbcon which must always
+ * be available for panics. Anything else we can reuse the stolen memory
+ * for is a boon.
+ */
+
 static int i915_adjust_stolen(struct drm_i915_private *i915,
 			      struct resource *dsm)
 {
@@ -173,14 +199,6 @@ static int i915_adjust_stolen(struct drm_i915_private *i915,
 	return 0;
 }
 
-static void i915_gem_cleanup_stolen(struct drm_i915_private *i915)
-{
-	if (!drm_mm_initialized(&i915->mm.stolen))
-		return;
-
-	drm_mm_takedown(&i915->mm.stolen);
-}
-
 static void g4x_get_stolen_reserved(struct drm_i915_private *i915,
 				    struct intel_uncore *uncore,
 				    resource_size_t *base,
@@ -395,8 +413,6 @@ static int i915_gem_init_stolen(struct intel_memory_region *mem)
 	resource_size_t reserved_base, stolen_top;
 	resource_size_t reserved_total, reserved_size;
 
-	mutex_init(&i915->mm.stolen_lock);
-
 	if (intel_vgpu_active(i915)) {
 		drm_notice(&i915->drm,
 			   "%s, disabling use of stolen memory\n",
@@ -513,258 +529,56 @@ static int i915_gem_init_stolen(struct intel_memory_region *mem)
 		return 0;
 
 	/* Basic memrange allocator for stolen space. */
-	drm_mm_init(&i915->mm.stolen, 0, i915->stolen_usable_size);
-
-	return 0;
+	return intel_region_ttm_init(mem);
 }
 
-static void dbg_poison(struct i915_ggtt *ggtt,
-		       dma_addr_t addr, resource_size_t size,
-		       u8 x)
-{
-#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)
-	if (!drm_mm_node_allocated(&ggtt->error_capture))
-		return;
-
-	if (ggtt->vm.bind_async_flags & I915_VMA_GLOBAL_BIND)
-		return; /* beware stop_machine() inversion */
-
-	GEM_BUG_ON(!IS_ALIGNED(size, PAGE_SIZE));
-
-	mutex_lock(&ggtt->error_mutex);
-	while (size) {
-		void __iomem *s;
-
-		ggtt->vm.insert_page(&ggtt->vm, addr,
-				     ggtt->error_capture.start,
-				     I915_CACHE_NONE, 0);
-		mb();
-
-		s = io_mapping_map_wc(&ggtt->iomap,
-				      ggtt->error_capture.start,
-				      PAGE_SIZE);
-		memset_io(s, x, PAGE_SIZE);
-		io_mapping_unmap(s);
-
-		addr += PAGE_SIZE;
-		size -= PAGE_SIZE;
-	}
-	mb();
-	ggtt->vm.clear_range(&ggtt->vm, ggtt->error_capture.start, PAGE_SIZE);
-	mutex_unlock(&ggtt->error_mutex);
-#endif
-}
-
-static struct sg_table *
-i915_pages_create_for_stolen(struct drm_device *dev,
-			     resource_size_t offset, resource_size_t size)
-{
-	struct drm_i915_private *i915 = to_i915(dev);
-	struct sg_table *st;
-	struct scatterlist *sg;
-
-	GEM_BUG_ON(range_overflows(offset, size, resource_size(&i915->dsm)));
-
-	/* We hide that we have no struct page backing our stolen object
-	 * by wrapping the contiguous physical allocation with a fake
-	 * dma mapping in a single scatterlist.
-	 */
-
-	st = kmalloc(sizeof(*st), GFP_KERNEL);
-	if (st == NULL)
-		return ERR_PTR(-ENOMEM);
-
-	if (sg_alloc_table(st, 1, GFP_KERNEL)) {
-		kfree(st);
-		return ERR_PTR(-ENOMEM);
-	}
-
-	sg = st->sgl;
-	sg->offset = 0;
-	sg->length = size;
-
-	sg_dma_address(sg) = (dma_addr_t)i915->dsm.start + offset;
-	sg_dma_len(sg) = size;
-
-	return st;
-}
-
-static int i915_gem_object_get_pages_stolen(struct drm_i915_gem_object *obj)
-{
-	struct drm_i915_private *i915 = to_i915(obj->base.dev);
-	struct sg_table *pages =
-		i915_pages_create_for_stolen(obj->base.dev,
-					     obj->stolen->start,
-					     obj->stolen->size);
-	if (IS_ERR(pages))
-		return PTR_ERR(pages);
-
-	dbg_poison(to_gt(i915)->ggtt,
-		   sg_dma_address(pages->sgl),
-		   sg_dma_len(pages->sgl),
-		   POISON_INUSE);
-
-	__i915_gem_object_set_pages(obj, pages, obj->stolen->size);
-
-	return 0;
-}
-
-static void i915_gem_object_put_pages_stolen(struct drm_i915_gem_object *obj,
-					     struct sg_table *pages)
-{
-	struct drm_i915_private *i915 = to_i915(obj->base.dev);
-	/* Should only be called from i915_gem_object_release_stolen() */
-
-	dbg_poison(to_gt(i915)->ggtt,
-		   sg_dma_address(pages->sgl),
-		   sg_dma_len(pages->sgl),
-		   POISON_FREE);
-
-	sg_free_table(pages);
-	kfree(pages);
-}
-
-static void
-i915_gem_object_release_stolen(struct drm_i915_gem_object *obj)
+struct drm_i915_gem_object *
+i915_gem_object_create_stolen(struct drm_i915_private *i915,
+			      resource_size_t size)
 {
-	struct drm_i915_private *i915 = to_i915(obj->base.dev);
-	struct drm_mm_node *stolen = fetch_and_zero(&obj->stolen);
-
-	GEM_BUG_ON(!stolen);
-	i915_gem_stolen_remove_node(i915, stolen);
-	kfree(stolen);
-
-	i915_gem_object_release_memory_region(obj);
+	return i915_gem_object_create_region(i915->mm.stolen_region, size, 0,
+					     I915_BO_ALLOC_CONTIGUOUS);
 }
 
-static const struct drm_i915_gem_object_ops i915_gem_object_stolen_ops = {
-	.name = "i915_gem_object_stolen",
-	.get_pages = i915_gem_object_get_pages_stolen,
-	.put_pages = i915_gem_object_put_pages_stolen,
-	.release = i915_gem_object_release_stolen,
-};
-
-static int __i915_gem_object_create_stolen(struct intel_memory_region *mem,
-					   struct drm_i915_gem_object *obj,
-					   struct drm_mm_node *stolen)
+static int init_stolen_smem(struct intel_memory_region *mem)
 {
-	static struct lock_class_key lock_class;
-	unsigned int cache_level;
-	unsigned int flags;
-	int err;
-
 	/*
-	 * Stolen objects are always physically contiguous since we just
-	 * allocate one big block underneath using the drm_mm range allocator.
+	 * Initialise stolen early so that we may reserve preallocated
+	 * objects for the BIOS to KMS transition.
 	 */
-	flags = I915_BO_ALLOC_CONTIGUOUS;
-
-	drm_gem_private_object_init(&mem->i915->drm, &obj->base, stolen->size);
-	i915_gem_object_init(obj, &i915_gem_object_stolen_ops, &lock_class, flags);
-
-	obj->stolen = stolen;
-	obj->read_domains = I915_GEM_DOMAIN_CPU | I915_GEM_DOMAIN_GTT;
-	cache_level = HAS_LLC(mem->i915) ? I915_CACHE_LLC : I915_CACHE_NONE;
-	i915_gem_object_set_cache_coherency(obj, cache_level);
-
-	if (WARN_ON(!i915_gem_object_trylock(obj, NULL)))
-		return -EBUSY;
-
-	i915_gem_object_init_memory_region(obj, mem);
-
-	err = i915_gem_object_pin_pages(obj);
-	if (err)
-		i915_gem_object_release_memory_region(obj);
-	i915_gem_object_unlock(obj);
-
-	return err;
+	return i915_gem_init_stolen(mem);
 }
 
-static int _i915_gem_object_stolen_init(struct intel_memory_region *mem,
-					struct drm_i915_gem_object *obj,
-					resource_size_t offset,
-					resource_size_t size,
-					resource_size_t page_size,
-					unsigned int flags)
+static int stolen_object_init(struct intel_memory_region *mem,
+			      struct drm_i915_gem_object *obj,
+			      resource_size_t offset,
+			      resource_size_t size,
+			      resource_size_t page_size,
+			      unsigned int flags)
 {
-	struct drm_i915_private *i915 = mem->i915;
-	struct drm_mm_node *stolen;
 	int ret;
 
-	if (!drm_mm_initialized(&i915->mm.stolen))
+	if (!mem->region_private)
 		return -ENODEV;
 
 	if (size == 0)
 		return -EINVAL;
 
-	/*
-	 * With discrete devices, where we lack a mappable aperture there is no
-	 * possible way to ever access this memory on the CPU side.
-	 */
-	if (mem->type == INTEL_MEMORY_STOLEN_LOCAL && !mem->io_size &&
-	    !(flags & I915_BO_ALLOC_GPU_ONLY))
-		return -ENOSPC;
-
-	stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
-	if (!stolen)
-		return -ENOMEM;
-
-	if (offset != I915_BO_INVALID_OFFSET) {
-		drm_dbg(&i915->drm,
-			"creating preallocated stolen object: stolen_offset=%pa, size=%pa\n",
-			&offset, &size);
-
-		stolen->start = offset;
-		stolen->size = size;
-		mutex_lock(&i915->mm.stolen_lock);
-		ret = drm_mm_reserve_node(&i915->mm.stolen, stolen);
-		mutex_unlock(&i915->mm.stolen_lock);
-	} else {
-		ret = i915_gem_stolen_insert_node(i915, stolen, size,
-						  mem->min_page_size);
-	}
+	ret = __i915_gem_ttm_object_init(mem, obj, offset, size, page_size, flags);
 	if (ret)
-		goto err_free;
+		return ret;
 
-	ret = __i915_gem_object_create_stolen(mem, obj, stolen);
+	ret = i915_gem_object_pin_pages_unlocked(obj);
 	if (ret)
-		goto err_remove;
+		i915_gem_object_put(obj);
 
-	return 0;
-
-err_remove:
-	i915_gem_stolen_remove_node(i915, stolen);
-err_free:
-	kfree(stolen);
 	return ret;
 }
 
-struct drm_i915_gem_object *
-i915_gem_object_create_stolen(struct drm_i915_private *i915,
-			      resource_size_t size)
-{
-	return i915_gem_object_create_region(i915->mm.stolen_region, size, 0, 0);
-}
-
-static int init_stolen_smem(struct intel_memory_region *mem)
-{
-	/*
-	 * Initialise stolen early so that we may reserve preallocated
-	 * objects for the BIOS to KMS transition.
-	 */
-	return i915_gem_init_stolen(mem);
-}
-
-static int release_stolen_smem(struct intel_memory_region *mem)
-{
-	i915_gem_cleanup_stolen(mem->i915);
-	return 0;
-}
-
 static const struct intel_memory_region_ops i915_region_stolen_smem_ops = {
 	.init = init_stolen_smem,
-	.release = release_stolen_smem,
-	.init_object = _i915_gem_object_stolen_init,
+	.release = intel_region_ttm_fini,
+	.init_object = stolen_object_init,
 };
 
 static int init_stolen_lmem(struct intel_memory_region *mem)
@@ -793,7 +607,7 @@ static int init_stolen_lmem(struct intel_memory_region *mem)
 	return 0;
 
 err_cleanup:
-	i915_gem_cleanup_stolen(mem->i915);
+	intel_region_ttm_fini(mem);
 	return err;
 }
 
@@ -801,14 +615,13 @@ static int release_stolen_lmem(struct intel_memory_region *mem)
 {
 	if (mem->io_size)
 		io_mapping_fini(&mem->iomap);
-	i915_gem_cleanup_stolen(mem->i915);
-	return 0;
+	return intel_region_ttm_fini(mem);
 }
 
 static const struct intel_memory_region_ops i915_region_stolen_lmem_ops = {
 	.init = init_stolen_lmem,
 	.release = release_stolen_lmem,
-	.init_object = _i915_gem_object_stolen_init,
+	.init_object = __i915_gem_ttm_object_init,
 };
 
 struct intel_memory_region *
@@ -896,7 +709,37 @@ i915_gem_stolen_smem_setup(struct drm_i915_private *i915, u16 type,
 	return mem;
 }
 
-bool i915_gem_object_is_stolen(const struct drm_i915_gem_object *obj)
+/**
+ * i915_gem_object_stolen_offset - return offset from start of stolen region
+ * @obj: the object to return the offset of
+ *
+ * Get the offset from stolen region if this object is currently placed in stolen memory.
+ *
+ * Return: offset from stolen if successful, I915_BO_INVALID_OFFSET otherwise
+ */
+u64 i915_gem_object_stolen_offset(struct drm_i915_gem_object *obj)
 {
-	return obj->ops == &i915_gem_object_stolen_ops;
+	struct ttm_buffer_object *ttm_obj;
+
+	if (!obj || !i915_gem_object_is_stolen(obj))
+		return I915_BO_INVALID_OFFSET;
+
+	ttm_obj = i915_gem_to_ttm(obj);
+	if (ttm_obj->resource->mem_type != I915_PL_STOLEN)
+		return I915_BO_INVALID_OFFSET;
+
+	return PFN_PHYS(ttm_obj->resource->start);
+}
+
+bool i915_gem_object_is_stolen(struct drm_i915_gem_object *obj)
+{
+	struct intel_memory_region *mr = READ_ONCE(obj->mm.region);
+
+#ifdef CONFIG_LOCKDEP
+	if (i915_gem_object_migratable(obj) &&
+	    i915_gem_object_evictable(obj))
+		assert_object_held(obj);
+#endif
+	return mr && (mr->type == INTEL_MEMORY_STOLEN_SYSTEM ||
+		      mr->type == INTEL_MEMORY_STOLEN_LOCAL);
 }
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_stolen.h b/drivers/gpu/drm/i915/gem/i915_gem_stolen.h
index d5005a39d130..b39cb6e6c768 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_stolen.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_stolen.h
@@ -10,17 +10,9 @@
 
 struct drm_i915_private;
 struct drm_mm_node;
+struct ttm_resource;
 struct drm_i915_gem_object;
 
-int i915_gem_stolen_insert_node(struct drm_i915_private *dev_priv,
-				struct drm_mm_node *node, u64 size,
-				unsigned alignment);
-int i915_gem_stolen_insert_node_in_range(struct drm_i915_private *dev_priv,
-					 struct drm_mm_node *node, u64 size,
-					 unsigned alignment, u64 start,
-					 u64 end);
-void i915_gem_stolen_remove_node(struct drm_i915_private *dev_priv,
-				 struct drm_mm_node *node);
 struct intel_memory_region *
 i915_gem_stolen_smem_setup(struct drm_i915_private *i915, u16 type,
 			   u16 instance);
@@ -32,7 +24,16 @@ struct drm_i915_gem_object *
 i915_gem_object_create_stolen(struct drm_i915_private *dev_priv,
 			      resource_size_t size);
 
-bool i915_gem_object_is_stolen(const struct drm_i915_gem_object *obj);
+u64 i915_gem_object_stolen_offset(struct drm_i915_gem_object *obj);
+bool i915_gem_object_is_stolen(struct drm_i915_gem_object *obj);
+struct ttm_resource *
+i915_gem_stolen_reserve_range(struct drm_i915_private *i915,
+			      resource_size_t size,
+			      u64 start, u64 end);
+u64 i915_gem_stolen_reserve_offset(struct ttm_resource *res);
+u64 i915_gem_stolen_reserve_size(struct ttm_resource *res);
+void i915_gem_stolen_release_range(struct drm_i915_private *i915,
+				   struct ttm_resource *res);
 
 #define I915_GEM_STOLEN_BIAS SZ_128K
 
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.h b/drivers/gpu/drm/i915/gem/i915_gem_ttm.h
index 73e371aa3850..81654a51df51 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.h
@@ -49,6 +49,13 @@ int __i915_gem_ttm_object_init(struct intel_memory_region *mem,
 			       resource_size_t size,
 			       resource_size_t page_size,
 			       unsigned int flags);
+int i915_gem_ttm_object_init_in_place(struct intel_memory_region *mem,
+				      struct drm_i915_gem_object *obj,
+				      resource_size_t size,
+				      resource_size_t page_size,
+				      unsigned int flags,
+				      u64 start,
+				      u64 end);
 
 /* Internal I915 TTM declarations and definitions below. */
 
diff --git a/drivers/gpu/drm/i915/gt/intel_rc6.c b/drivers/gpu/drm/i915/gt/intel_rc6.c
index b4770690e794..269b7f467fdf 100644
--- a/drivers/gpu/drm/i915/gt/intel_rc6.c
+++ b/drivers/gpu/drm/i915/gt/intel_rc6.c
@@ -355,9 +355,9 @@ static int vlv_rc6_init(struct intel_rc6 *rc6)
 
 	GEM_BUG_ON(range_overflows_end_t(u64,
 					 i915->dsm.start,
-					 pctx->stolen->start,
+					 i915_gem_object_stolen_offset(pctx),
 					 U32_MAX));
-	pctx_paddr = i915->dsm.start + pctx->stolen->start;
+	pctx_paddr = i915->dsm.start + i915_gem_object_stolen_offset(pctx);
 	intel_uncore_write(uncore, VLV_PCBR, pctx_paddr);
 
 out:
diff --git a/drivers/gpu/drm/i915/gt/selftest_reset.c b/drivers/gpu/drm/i915/gt/selftest_reset.c
index 37c38bdd5f47..75bc7d90c9dc 100644
--- a/drivers/gpu/drm/i915/gt/selftest_reset.c
+++ b/drivers/gpu/drm/i915/gt/selftest_reset.c
@@ -6,6 +6,7 @@
 #include <linux/crc32.h>
 
 #include "gem/i915_gem_stolen.h"
+#include "intel_region_ttm.h"
 
 #include "i915_memcpy.h"
 #include "i915_selftest.h"
@@ -83,6 +84,7 @@ __igt_reset_stolen(struct intel_gt *gt,
 		dma_addr_t dma = (dma_addr_t)dsm->start + (page << PAGE_SHIFT);
 		void __iomem *s;
 		void *in;
+		bool busy;
 
 		ggtt->vm.insert_page(&ggtt->vm, dma,
 				     ggtt->error_capture.start,
@@ -93,9 +95,9 @@ __igt_reset_stolen(struct intel_gt *gt,
 				      ggtt->error_capture.start,
 				      PAGE_SIZE);
 
-		if (!__drm_mm_interval_first(&gt->i915->mm.stolen,
-					     page << PAGE_SHIFT,
-					     ((page + 1) << PAGE_SHIFT) - 1))
+		busy = intel_region_ttm_range_busy(gt->i915->mm.stolen_region,
+						   PFN_PHYS(page), PAGE_SIZE);
+		if (!busy)
 			memset_io(s, STACK_MAGIC, PAGE_SIZE);
 
 		in = (void __force *)s;
@@ -124,6 +126,7 @@ __igt_reset_stolen(struct intel_gt *gt,
 		void __iomem *s;
 		void *in;
 		u32 x;
+		bool busy;
 
 		ggtt->vm.insert_page(&ggtt->vm, dma,
 				     ggtt->error_capture.start,
@@ -139,10 +142,9 @@ __igt_reset_stolen(struct intel_gt *gt,
 			in = tmp;
 		x = crc32_le(0, in, PAGE_SIZE);
 
-		if (x != crc[page] &&
-		    !__drm_mm_interval_first(&gt->i915->mm.stolen,
-					     page << PAGE_SHIFT,
-					     ((page + 1) << PAGE_SHIFT) - 1)) {
+		busy = intel_region_ttm_range_busy(gt->i915->mm.stolen_region,
+						   PFN_PHYS(page), PAGE_SIZE);
+		if (x != crc[page] && !busy) {
 			pr_debug("unused stolen page %pa modified by GPU reset\n",
 				 &page);
 			if (count++ == 0)
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 94e5c29d2ee3..e538b8f71dcc 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -32,6 +32,7 @@
 
 #include <drm/drm_debugfs.h>
 
+#include "gem/i915_gem_region.h"
 #include "gem/i915_gem_context.h"
 #include "gt/intel_gt.h"
 #include "gt/intel_gt_buffer_pool.h"
@@ -157,6 +158,7 @@ i915_debugfs_describe_obj(struct seq_file *m, struct drm_i915_gem_object *obj)
 	struct drm_i915_private *dev_priv = to_i915(obj->base.dev);
 	struct i915_vma *vma;
 	int pin_count = 0;
+	u64 offset;
 
 	seq_printf(m, "%pK: %c%c%c %8zdKiB %02x %02x %s%s%s",
 		   &obj->base,
@@ -241,8 +243,9 @@ i915_debugfs_describe_obj(struct seq_file *m, struct drm_i915_gem_object *obj)
 	spin_unlock(&obj->vma.lock);
 
 	seq_printf(m, " (pinned x %d)", pin_count);
-	if (i915_gem_object_is_stolen(obj))
-		seq_printf(m, " (stolen: %08llx)", obj->stolen->start);
+	offset = i915_gem_object_stolen_offset(obj);
+	if (offset != I915_BO_INVALID_OFFSET)
+		seq_printf(m, " (stolen: %08llx)", offset);
 	if (i915_gem_object_is_framebuffer(obj))
 		seq_printf(m, " (fb)");
 }
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 06e7c2802c5e..d05cf2fc3ef6 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -231,11 +231,6 @@ struct i915_gem_mm {
 	 * support stolen.
 	 */
 	struct intel_memory_region *stolen_region;
-	/** Memory allocator for GTT stolen memory */
-	struct drm_mm stolen;
-	/** Protects the usage of the GTT stolen memory allocator. This is
-	 * always the inner lock when overlapping with struct_mutex. */
-	struct mutex stolen_lock;
 
 	/* Protects bound_list/unbound_list and #drm_i915_gem_object.mm.link */
 	spinlock_t obj_lock;
diff --git a/drivers/gpu/drm/i915/intel_region_ttm.c b/drivers/gpu/drm/i915/intel_region_ttm.c
index 7d49ea72e33f..4450b4897d59 100644
--- a/drivers/gpu/drm/i915/intel_region_ttm.c
+++ b/drivers/gpu/drm/i915/intel_region_ttm.c
@@ -189,11 +189,12 @@ intel_region_ttm_resource_to_rsgt(struct intel_memory_region *mem,
 	}
 }
 
-#ifdef CONFIG_DRM_I915_SELFTEST
 /**
  * intel_region_ttm_resource_alloc - Allocate memory resources from a region
  * @mem: The memory region,
  * @size: The requested size in bytes
+ * @start: start of allowed range
+ * @end: end of allowed range
  * @flags: Allocation flags
  *
  * This functionality is provided only for callers that need to allocate
@@ -207,8 +208,9 @@ intel_region_ttm_resource_to_rsgt(struct intel_memory_region *mem,
  */
 struct ttm_resource *
 intel_region_ttm_resource_alloc(struct intel_memory_region *mem,
-				resource_size_t offset,
 				resource_size_t size,
+				u64 start,
+				u64 end,
 				unsigned int flags)
 {
 	struct ttm_resource_manager *man = mem->region_private;
@@ -219,9 +221,9 @@ intel_region_ttm_resource_alloc(struct intel_memory_region *mem,
 
 	if (flags & I915_BO_ALLOC_CONTIGUOUS)
 		place.flags |= TTM_PL_FLAG_CONTIGUOUS;
-	if (offset != I915_BO_INVALID_OFFSET) {
-		place.fpfn = offset >> PAGE_SHIFT;
-		place.lpfn = place.fpfn + (size >> PAGE_SHIFT);
+	if (start || end) {
+		place.fpfn = PFN_DOWN(start);
+		place.lpfn = PFN_UP(end);
 	} else if (mem->io_size && mem->io_size < mem->total) {
 		if (flags & I915_BO_ALLOC_GPU_ONLY) {
 			place.flags |= TTM_PL_FLAG_TOPDOWN;
@@ -242,8 +244,6 @@ intel_region_ttm_resource_alloc(struct intel_memory_region *mem,
 	return ret ? ERR_PTR(ret) : res;
 }
 
-#endif
-
 /**
  * intel_region_ttm_resource_free - Free a resource allocated from a resource manager
  * @mem: The region the resource was allocated from.
@@ -261,3 +261,25 @@ void intel_region_ttm_resource_free(struct intel_memory_region *mem,
 
 	man->func->free(man, res);
 }
+
+/**
+ * intel_region_ttm_range_busy - check whether range has any allocations
+ * @mem: The region to check
+ * @start: the start of the range to check
+ * @size: size of the range to check
+ *
+ * Return: true if something is alloceted within the region, false otherwise.
+ */
+bool intel_region_ttm_range_busy(struct intel_memory_region *mem,
+				 u64 start, u64 size)
+{
+	struct ttm_resource *dummy;
+
+	dummy = intel_region_ttm_resource_alloc(mem, size, start, start + size,
+						I915_BO_ALLOC_CONTIGUOUS);
+	if (IS_ERR(dummy))
+		return true;
+
+	intel_region_ttm_resource_free(mem, dummy);
+	return false;
+}
diff --git a/drivers/gpu/drm/i915/intel_region_ttm.h b/drivers/gpu/drm/i915/intel_region_ttm.h
index cf9d86dcf409..1e88472fb2ea 100644
--- a/drivers/gpu/drm/i915/intel_region_ttm.h
+++ b/drivers/gpu/drm/i915/intel_region_ttm.h
@@ -29,15 +29,17 @@ intel_region_ttm_resource_to_rsgt(struct intel_memory_region *mem,
 void intel_region_ttm_resource_free(struct intel_memory_region *mem,
 				    struct ttm_resource *res);
 
+bool intel_region_ttm_range_busy(struct intel_memory_region *mem,
+				 u64 start, u64 size);
+
 int intel_region_to_ttm_type(const struct intel_memory_region *mem);
 
 struct ttm_device_funcs *i915_ttm_driver(void);
 
-#ifdef CONFIG_DRM_I915_SELFTEST
 struct ttm_resource *
 intel_region_ttm_resource_alloc(struct intel_memory_region *mem,
-				resource_size_t offset,
 				resource_size_t size,
+				u64 start,
+				u64 end,
 				unsigned int flags);
-#endif
 #endif /* _INTEL_REGION_TTM_H_ */
diff --git a/drivers/gpu/drm/i915/selftests/mock_region.c b/drivers/gpu/drm/i915/selftests/mock_region.c
index 670557ce1024..15be2440cdb8 100644
--- a/drivers/gpu/drm/i915/selftests/mock_region.c
+++ b/drivers/gpu/drm/i915/selftests/mock_region.c
@@ -26,8 +26,9 @@ static int mock_region_get_pages(struct drm_i915_gem_object *obj)
 	int err;
 
 	obj->mm.res = intel_region_ttm_resource_alloc(obj->mm.region,
-						      obj->bo_offset,
 						      obj->base.size,
+						      obj->bo_offset,
+						      obj->bo_offset + obj->base.size,
 						      obj->flags);
 	if (IS_ERR(obj->mm.res))
 		return PTR_ERR(obj->mm.res);
-- 
2.25.1