[PATCH 09/16] drm/amdgpu: create kernel doorbell page

[Shashank Sharma]

From: Shashank Sharma <contactshashanksharma at gmail.com>

This patch:
- creates a doorbell page for graphics driver usages.
- removes the adev->doorbell.ptr variable, replaces it with
  kernel-doorbell-bo's cpu address.

Cc: Alex Deucher <alexander.deucher at amd.com>
Cc: Christian Koenig <christian.koenig at amd.com>
Signed-off-by: Shashank Sharma <shashank.sharma at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h  | 16 ++++++-
 .../gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c  | 44 +++++++++++++++----
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c       |  7 +++
 3 files changed, 57 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h
index 6581b78fe438..10a9bb10e974 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h
@@ -49,10 +49,13 @@ struct amdgpu_doorbell {
 	/* doorbell mmio */
 	resource_size_t		base;
 	resource_size_t		size;
-	u32 __iomem		*ptr;
+	u32	__iomem		*ptr;
 
 	/* Number of doorbells reserved for amdgpu kernel driver */
 	u32 num_kernel_doorbells;
+
+	/* For kernel doorbell pages */
+	struct amdgpu_doorbell_obj kernel_doorbells;
 };
 
 /* Reserved doorbells for amdgpu (including multimedia).
@@ -369,6 +372,17 @@ void amdgpu_doorbell_free_page(struct amdgpu_device *adev,
 int amdgpu_doorbell_alloc_page(struct amdgpu_device *adev,
 				struct amdgpu_doorbell_obj *db_obj);
 
+/**
+ * amdgpu_doorbell_create_kernel_doorbells - Create kernel doorbells for graphics
+ *
+ * @adev: amdgpu_device pointer
+ *
+ * Creates doorbells for graphics driver
+ *
+ * returns 0 on success, error otherwise.
+ */
+int amdgpu_doorbell_create_kernel_doorbells(struct amdgpu_device *adev);
+
 #define RDOORBELL32(index) amdgpu_mm_rdoorbell(adev, (index))
 #define WDOORBELL32(index, v) amdgpu_mm_wdoorbell(adev, (index), (v))
 #define RDOORBELL64(index) amdgpu_mm_rdoorbell64(adev, (index))
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c
index 8be15b82b545..b46fe8b1378d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c
@@ -160,6 +160,38 @@ int amdgpu_doorbell_alloc_page(struct amdgpu_device *adev,
 	return 0;
 }
 
+/**
+ * amdgpu_doorbell_create_kernel_doorbells - Create kernel doorbells for graphics
+ *
+ * @adev: amdgpu_device pointer
+ *
+ * Creates doorbells for graphics driver
+ *
+ * returns 0 on success, error otherwise.
+ */
+int amdgpu_doorbell_create_kernel_doorbells(struct amdgpu_device *adev)
+{
+	int r;
+	struct amdgpu_doorbell_obj *kernel_doorbells = &adev->doorbell.kernel_doorbells;
+
+	kernel_doorbells->doorbell_bitmap = bitmap_zalloc(adev->doorbell.num_kernel_doorbells,
+							  GFP_KERNEL);
+	if (!kernel_doorbells->doorbell_bitmap) {
+		DRM_ERROR("Failed to create kernel doorbell bitmap\n");
+		return -ENOMEM;
+	}
+
+	kernel_doorbells->size = adev->doorbell.num_kernel_doorbells * sizeof(u32);
+	r = amdgpu_doorbell_alloc_page(adev, kernel_doorbells);
+	if (r) {
+		bitmap_free(kernel_doorbells->doorbell_bitmap);
+		DRM_ERROR("Failed to allocate kernel doorbells, err=%d\n", r);
+		return r;
+	}
+
+	return 0;
+}
+
 /*
  * GPU doorbell aperture helpers function.
  */
@@ -179,7 +211,6 @@ int amdgpu_device_doorbell_init(struct amdgpu_device *adev)
 		adev->doorbell.base = 0;
 		adev->doorbell.size = 0;
 		adev->doorbell.num_kernel_doorbells = 0;
-		adev->doorbell.ptr = NULL;
 		return 0;
 	}
 
@@ -208,12 +239,7 @@ int amdgpu_device_doorbell_init(struct amdgpu_device *adev)
 	if (adev->asic_type >= CHIP_VEGA10)
 		adev->doorbell.num_kernel_doorbells += 0x400;
 
-	adev->doorbell.ptr = ioremap(adev->doorbell.base,
-				     adev->doorbell.num_kernel_doorbells *
-				     sizeof(u32));
-	if (adev->doorbell.ptr == NULL)
-		return -ENOMEM;
-
+	adev->doorbell.ptr = ioremap(adev->doorbell.base, adev->doorbell.size);
 	return 0;
 }
 
@@ -226,6 +252,6 @@ int amdgpu_device_doorbell_init(struct amdgpu_device *adev)
  */
 void amdgpu_device_doorbell_fini(struct amdgpu_device *adev)
 {
-	iounmap(adev->doorbell.ptr);
-	adev->doorbell.ptr = NULL;
+	bitmap_free(adev->doorbell.kernel_doorbells.doorbell_bitmap);
+	amdgpu_doorbell_free_page(adev, &adev->doorbell.kernel_doorbells);
 }
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 203d77a20507..75c6852845c4 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -1866,6 +1866,13 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
 		return r;
 	}
 
+	/* Create a boorbell page for kernel usages */
+	r = amdgpu_doorbell_create_kernel_doorbells(adev);
+	if (r) {
+		DRM_ERROR("Failed to initialize kernel doorbells. \n");
+		return r;
+	}
+
 	/* Initialize preemptible memory pool */
 	r = amdgpu_preempt_mgr_init(adev);
 	if (r) {
-- 
2.40.0