[PATCH v2 7/8] drm/amdgpu: create doorbell kernel object

[Shashank Sharma <shashank.sharma@xxxxxxx>]

From: Shashank Sharma <contactshashanksharma@xxxxxxxxx>

This patch does the following:
- Initializes TTM range management for domain DOORBELL.
- Introduces a kernel bo for doorbell management in form of mman.doorbell_kernel_bo.
  This bo holds the kernel doorbell space now.
- Removes ioremapping of doorbell-kernel memory, as its not required now.

V2:
- Addressed review comments from Christian:
    - do not use kernel_create_at(0), use kernel_create() instead.
    - do not use ttm_resource_manager, use range_manager instead.
    - do not ioremap doorbell, TTM will do that.
- Split one big patch into 2

Cc: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: Christian Koenig <christian.koenig@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Shashank Sharma <shashank.sharma@xxxxxxx>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 22 ++++++++++++++++++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h |  7 +++++++
 2 files changed, 29 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index e9dc24191fc8..086e83c17c0f 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -1879,12 +1879,32 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
 		return r;
 	}
 
+	r = amdgpu_ttm_init_on_chip(adev, AMDGPU_PL_DOORBELL, adev->doorbell.doorbell_aper_size);
+	if (r) {
+		DRM_ERROR("Failed initializing oa heap.\n");
+		return r;
+	}
+
 	if (amdgpu_bo_create_kernel(adev, PAGE_SIZE, PAGE_SIZE,
 				AMDGPU_GEM_DOMAIN_GTT,
 				&adev->mman.sdma_access_bo, NULL,
 				&adev->mman.sdma_access_ptr))
 		DRM_WARN("Debug VRAM access will use slowpath MM access\n");
 
+	/* Create a doorbell BO for kernel usages */
+	r = amdgpu_bo_create_kernel(adev,
+				    adev->mman.doorbell_kernel_bo_size,
+				    PAGE_SIZE,
+				    AMDGPU_GEM_DOMAIN_DOORBELL,
+				    &adev->mman.doorbell_kernel_bo,
+				    &adev->mman.doorbell_gpu_addr,
+				    (void **)&adev->mman.doorbell_cpu_addr);
+
+	if (r) {
+		DRM_ERROR("Failed to create doorbell BO, err=%d\n", r);
+		return r;
+	}
+
 	return 0;
 }
 
@@ -1908,6 +1928,8 @@ void amdgpu_ttm_fini(struct amdgpu_device *adev)
 				      NULL, NULL);
 	amdgpu_bo_free_kernel(&adev->mman.sdma_access_bo, NULL,
 					&adev->mman.sdma_access_ptr);
+	amdgpu_bo_free_kernel(&adev->mman.doorbell_kernel_bo,
+			      NULL, (void **)&adev->mman.doorbell_cpu_addr);
 	amdgpu_ttm_fw_reserve_vram_fini(adev);
 	amdgpu_ttm_drv_reserve_vram_fini(adev);
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
index 9cf5d8419965..50748ff1dd3c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
@@ -97,6 +97,13 @@ struct amdgpu_mman {
 	/* PAGE_SIZE'd BO for process memory r/w over SDMA. */
 	struct amdgpu_bo	*sdma_access_bo;
 	void			*sdma_access_ptr;
+
+	/* doorbells reserved for the kernel driver */
+	u32			num_kernel_doorbells;	/* Number of doorbells actually reserved for kernel */
+	uint64_t		doorbell_kernel_bo_size;
+	uint64_t		doorbell_gpu_addr;
+	struct amdgpu_bo	*doorbell_kernel_bo;
+	u32			*doorbell_cpu_addr;
 };
 
 struct amdgpu_copy_mem {
-- 
2.34.1