[PATCH 9/9] drm/amdgpu: add VM support for huge pages

[ckoenig.leichtzumerken@xxxxxxxxx (Christian König)]

From: Christian König <christian.koenig@xxxxxxx>

Convert GTT mappings into linear ones for huge page handling.

Signed-off-by: Christian König <christian.koenig at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 3c86381..16454bd 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -1732,6 +1732,7 @@ static int amdgpu_vm_bo_split_mapping(struct amdgpu_device *adev,
 	}
 
 	do {
+		dma_addr_t *dma_addr = NULL;
 		uint64_t max_entries;
 		uint64_t addr, last;
 
@@ -1745,15 +1746,32 @@ static int amdgpu_vm_bo_split_mapping(struct amdgpu_device *adev,
 		}
 
 		if (pages_addr) {
+			uint64_t count;
+
 			max_entries = min(max_entries, 16ull * 1024ull);
-			addr = 0;
+			for (count = 1; count < max_entries; ++count) {
+				uint64_t idx = pfn + count;
+
+				if (pages_addr[idx] !=
+				    (pages_addr[idx - 1] + PAGE_SIZE))
+					break;
+			}
+
+			if (count < 64) {
+				addr = pfn << PAGE_SHIFT;
+				dma_addr = pages_addr;
+			} else {
+				addr = pages_addr[pfn];
+				max_entries = count;
+			}
+
 		} else if (flags & AMDGPU_PTE_VALID) {
 			addr += adev->vm_manager.vram_base_offset;
+			addr += pfn << PAGE_SHIFT;
 		}
-		addr += pfn << PAGE_SHIFT;
 
 		last = min((uint64_t)mapping->last, start + max_entries - 1);
-		r = amdgpu_vm_bo_update_mapping(adev, exclusive, pages_addr, vm,
+		r = amdgpu_vm_bo_update_mapping(adev, exclusive, dma_addr, vm,
 						start, last, flags, addr,
 						fence);
 		if (r)
-- 
2.7.4