Re: [PATCH] drm/ttm: rename ttm_place::fpfn/lpfn to param1/param2
From: Tvrtko Ursulin
Date: Thu Jun 18 2026 - 14:41:42 EST
On 18/06/2026 15:39, Arunpravin Paneer Selvam wrote:
The fpfn/lpfn fields in struct ttm_place were named after page frame
numbers, but they are really just placement parameters passed to the
backend resource manager. Rename them to the generic param1/param2
and document that their interpretation is backend-defined. The VRAM
range manager continues to treat them as the first and last valid
page frame number, so behaviour is unchanged.
This decouples the API from PFN/range-specific semantics so that
these fields can be used more flexibly in the future (e.g.,
mask-based or segment-aware placement constraints). No functional
change.
Suggested-by: Christian König <christian.koenig@xxxxxxx>
Cc: Christian König <christian.koenig@xxxxxxx>
Cc: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
Cc: Matthew Auld <matthew.auld@xxxxxxxxx>
Cc: Matthew Brost <matthew.brost@xxxxxxxxx>
Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@xxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c | 16 +++---
drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h | 4 +-
drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c | 8 +--
drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 46 +++++++--------
drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 24 ++++----
drivers/gpu/drm/amd/amdgpu/amdgpu_uvd.c | 4 +-
drivers/gpu/drm/amd/amdgpu/amdgpu_vce.c | 16 +++---
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 6 +-
drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 32 +++++------
drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 2 +-
.../gpu/drm/amd/ras/ras_mgr/amdgpu_ras_cmd.c | 2 +-
drivers/gpu/drm/drm_gem_vram_helper.c | 4 +-
drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 18 +++---
drivers/gpu/drm/i915/i915_ttm_buddy_manager.c | 56 +++++++++----------
drivers/gpu/drm/i915/intel_region_ttm.c | 14 ++---
drivers/gpu/drm/loongson/lsdc_ttm.c | 4 +-
drivers/gpu/drm/nouveau/nouveau_bo.c | 22 ++++----
drivers/gpu/drm/nouveau/nouveau_mem.c | 8 +--
drivers/gpu/drm/qxl/qxl_object.c | 4 +-
drivers/gpu/drm/qxl/qxl_ttm.c | 4 +-
drivers/gpu/drm/radeon/radeon_object.c | 28 +++++-----
drivers/gpu/drm/radeon/radeon_ttm.c | 18 +++---
drivers/gpu/drm/radeon/radeon_uvd.c | 8 +--
drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c | 16 +++---
drivers/gpu/drm/ttm/tests/ttm_mock_manager.c | 8 +--
drivers/gpu/drm/ttm/ttm_bo_util.c | 4 +-
drivers/gpu/drm/ttm/ttm_range_manager.c | 18 +++---
drivers/gpu/drm/vmwgfx/vmwgfx_bo.c | 30 +++++-----
drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c | 8 +--
drivers/gpu/drm/xe/xe_bo.c | 24 ++++----
drivers/gpu/drm/xe/xe_ttm_vram_mgr.c | 40 ++++++-------
include/drm/ttm/ttm_placement.h | 15 +++--
32 files changed, 259 insertions(+), 252 deletions(-)
<snip>
if (unlikely(ret)) {
@@ -124,8 +124,8 @@ static bool ttm_range_man_intersects(struct ttm_resource_manager *man,
u32 num_pages = PFN_UP(size);
/* Don't evict BOs outside of the requested placement range */
- if (place->fpfn >= (node->start + num_pages) ||
- (place->lpfn && place->lpfn <= node->start))
+ if (place->param1 >= (node->start + num_pages) ||
+ (place->param2 && place->param2 <= node->start))
return false;
return true;
@@ -139,8 +139,8 @@ static bool ttm_range_man_compatible(struct ttm_resource_manager *man,
struct drm_mm_node *node = &to_ttm_range_mgr_node(res)->mm_nodes[0];
u32 num_pages = PFN_UP(size);
- if (node->start < place->fpfn ||
- (place->lpfn && (node->start + num_pages) > place->lpfn))
+ if (node->start < place->param1 ||
+ (place->param2 && (node->start + num_pages) > place->param2))
return false;
Not very readable ie. good for ease of maintenance - how about an union? Would also avoid having to touch all the drivers.
Something like:
union {
struct {
u64 fpfn;
u64 lpfn;
};
u64 drvparam[2];
};
Regards,
Tvrtko
diff --git a/include/drm/ttm/ttm_placement.h b/include/drm/ttm/ttm_placement.h
index ab2639e42c54..2c38674be102 100644
--- a/include/drm/ttm/ttm_placement.h
+++ b/include/drm/ttm/ttm_placement.h
@@ -73,16 +73,23 @@
/**
* struct ttm_place
*
- * @fpfn: first valid page frame number to put the object
- * @lpfn: last valid page frame number to put the object
+ * @param1: generic placement parameter, interpretation depends on the
+ * backend resource manager. For range-based managers (e.g. the
+ * VRAM range manager, the buddy managers in amdgpu/i915/xe and
+ * the TTM range manager) this is the start of the allowed range,
+ * typically expressed as a page frame number.
+ * @param2: generic placement parameter, interpretation depends on the
+ * backend resource manager. For range-based managers this is the
+ * exclusive end of the allowed range (a value of 0 means
+ * "no upper bound").
* @mem_type: One of TTM_PL_* where the resource should be allocated from.
* @flags: memory domain and caching flags for the object
*
* Structure indicating a possible place to put an object.
*/
struct ttm_place {
- uint64_t fpfn;
- uint64_t lpfn;
+ uint64_t param1;
+ uint64_t param2;
uint32_t mem_type;
uint32_t flags;
};