[PATCH] drm/amd/display: Implement functions to let DC allocate GPU memory

[Bhawanpreet Lakha]

From: Harry Wentland <harry.wentland at amd.com>

[Why]
DC needs to communicate with PM FW through GPU memory. In order
to do so we need to be able to allocate memory from within DC.

[How]
Call amdgpu_bo_create_kernel to allocate GPU memory and use a
list in amdgpu_display_manager to track our allocations so we
can clean them up later.

Signed-off-by: Harry Wentland <harry.wentland at amd.com>
---
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c |  2 +
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h |  9 +++++
 .../amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 40 +++++++++++++++++--
 3 files changed, 48 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index e490fc2486f7..83ec92a69cba 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -1017,6 +1017,8 @@ static int amdgpu_dm_init(struct amdgpu_device *adev)
 
 	init_data.soc_bounding_box = adev->dm.soc_bounding_box;
 
+	INIT_LIST_HEAD(&adev->dm.da_list);
+
 	/* Display Core create. */
 	adev->dm.dc = dc_create(&init_data);
 
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
index 38bc0f88b29c..49137924a855 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
@@ -130,6 +130,13 @@ struct amdgpu_dm_backlight_caps {
 	bool aux_support;
 };
 
+struct dal_allocation {
+	struct list_head list;
+	struct amdgpu_bo *bo;
+	void *cpu_ptr;
+	u64 gpu_addr;
+};
+
 /**
  * struct amdgpu_display_manager - Central amdgpu display manager device
  *
@@ -350,6 +357,8 @@ struct amdgpu_display_manager {
 	 */
 	struct amdgpu_encoder mst_encoders[AMDGPU_DM_MAX_CRTC];
 	bool force_timing_sync;
+
+	struct list_head da_list;
 };
 
 enum dsc_clock_force_state {
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
index 3244a6ea7a65..5dc426e6e785 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
@@ -652,8 +652,31 @@ void *dm_helpers_allocate_gpu_mem(
 		size_t size,
 		long long *addr)
 {
-	// TODO
-	return NULL;
+	struct amdgpu_device *adev = ctx->driver_context;
+	struct dal_allocation *da;
+	u32 domain = (type == DC_MEM_ALLOC_TYPE_GART) ?
+		AMDGPU_GEM_DOMAIN_GTT : AMDGPU_GEM_DOMAIN_VRAM;
+	int ret;
+
+	da = kzalloc(sizeof(struct dal_allocation), GFP_KERNEL);
+	if (!da)
+		return NULL;
+
+	ret = amdgpu_bo_create_kernel(adev, size, PAGE_SIZE,
+				      domain, &da->bo,
+				      &da->gpu_addr, &da->cpu_ptr);
+
+	*addr = da->gpu_addr;
+
+	if (ret) {
+		kfree(da);
+		return NULL;
+	}
+
+	/* add da to list in dm */
+	list_add(&da->list, &adev->dm.da_list);
+
+	return da->cpu_ptr;
 }
 
 void dm_helpers_free_gpu_mem(
@@ -661,5 +684,16 @@ void dm_helpers_free_gpu_mem(
 		enum dc_gpu_mem_alloc_type type,
 		void *pvMem)
 {
-	// TODO
+	struct amdgpu_device *adev = ctx->driver_context;
+	struct dal_allocation *da;
+
+	/* walk the da list in DM */
+	list_for_each_entry(da, &adev->dm.da_list, list) {
+		if (pvMem == da->cpu_ptr) {
+			amdgpu_bo_free_kernel(&da->bo, &da->gpu_addr, &da->cpu_ptr);
+			list_del(&da->list);
+			kfree(da);
+			break;
+		}
+	}
 }
-- 
2.25.1