[PATCH v2] drm/amdgpu: simplify vram alloc logic since 2GB limitation removed

[Yifan Zhang]

This is a followup of commit b2dba064c9bd ("drm/amdgpu: Handle
sg size limit for contiguous allocation").

2GB limitation in VRAM allocation is removed in above commit.
The remaing_size calculation was to address the 2GB limitation
in contiguous VRAM allocation, thus no longer needed. Simplify
vram alloc logic.

Signed-off-by: Yifan Zhang <yifan1.zhang at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
index 7d26a962f811..3d129fd61fa7 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
@@ -455,7 +455,7 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
 	struct amdgpu_bo *bo = ttm_to_amdgpu_bo(tbo);
 	u64 vis_usage = 0, max_bytes, min_block_size;
 	struct amdgpu_vram_mgr_resource *vres;
-	u64 size, remaining_size, lpfn, fpfn;
+	u64 size, lpfn, fpfn;
 	unsigned int adjust_dcc_size = 0;
 	struct drm_buddy *mm = &mgr->mm;
 	struct drm_buddy_block *block;
@@ -516,25 +516,23 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
 	    adev->gmc.gmc_funcs->get_dcc_alignment)
 		adjust_dcc_size = amdgpu_gmc_get_dcc_alignment(adev);
 
-	remaining_size = (u64)vres->base.size;
+	size = (u64)vres->base.size;
 	if (bo->flags & AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS && adjust_dcc_size) {
 		unsigned int dcc_size;
 
 		dcc_size = roundup_pow_of_two(vres->base.size + adjust_dcc_size);
-		remaining_size = (u64)dcc_size;
+		size = (u64)dcc_size;
 
 		vres->flags |= DRM_BUDDY_TRIM_DISABLE;
 	}
 
 	mutex_lock(&mgr->lock);
-	while (remaining_size) {
+	while (true) {
 		if (tbo->page_alignment)
 			min_block_size = (u64)tbo->page_alignment << PAGE_SHIFT;
 		else
 			min_block_size = mgr->default_page_size;
 
-		size = remaining_size;
-
 		if (bo->flags & AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS && adjust_dcc_size)
 			min_block_size = size;
 		else if ((size >= (u64)pages_per_block << PAGE_SHIFT) &&
@@ -562,10 +560,7 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
 		if (unlikely(r))
 			goto error_free_blocks;
 
-		if (size > remaining_size)
-			remaining_size = 0;
-		else
-			remaining_size -= size;
+		break;
 	}
 	mutex_unlock(&mgr->lock);
 
-- 
2.43.0