Am 29.03.23 um 17:47 schrieb Shashank Sharma:
From: Shashank Sharma <contactshashanksha...@gmail.com>

This patch adds helper functions to create and free doorbell
pages for kernel objects.

Cc: Alex Deucher <alexander.deuc...@amd.com>
Cc: Christian Koenig <christian.koe...@amd.com>
Signed-off-by: Shashank Sharma <shashank.sha...@amd.com>
---
  drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h  | 41 ++++++++++++++++
  .../gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c  | 49 +++++++++++++++++++
  2 files changed, 90 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h
index f9c3b77bf65d..6581b78fe438 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h
@@ -27,6 +27,24 @@
  /*
   * GPU doorbell structures, functions & helpers
   */
+
+/* Structure to hold doorbell pages from PCI doorbell BAR */
+struct amdgpu_doorbell_obj {
+       struct amdgpu_bo *bo;
+       uint64_t gpu_addr;

Do we need to map the doorbells into the GART for something?

On the other hand we probably don't have the check to not do it in amdgpu_bo_create_reserved yet.

+       uint32_t *cpu_addr;
+       uint32_t size;
+
+       /* First index in this object */
+       uint32_t start;
+
+       /* Last index in this object */
+       uint32_t end;
+
+       /* bitmap for dynamic doorbell allocation from this object */
+       unsigned long *doorbell_bitmap;
+};
+

Do we really need a separate structure for all this? As far as I can see this is just part of the doorbell handling.

  struct amdgpu_doorbell {
        /* doorbell mmio */
        resource_size_t         base;
@@ -328,6 +346,29 @@ int amdgpu_device_doorbell_init(struct amdgpu_device 
*adev);
   */
  void amdgpu_device_doorbell_fini(struct amdgpu_device *adev);
+/**
+ * amdgpu_doorbell_free_page - Free a doorbell page
+ *
+ * @adev: amdgpu_device pointer
+ *
+ * @db_age: previously allocated doobell page details
+ *
+ */
+void amdgpu_doorbell_free_page(struct amdgpu_device *adev,
+                               struct amdgpu_doorbell_obj *db_obj);
+
+/**
+ * amdgpu_doorbell_alloc_page - create a page from doorbell pool
+ *
+ * @adev: amdgpu_device pointer
+ *
+ * @db_age: doobell page structure to fill details with
+ *
+ * returns 0 on success, else error number
+ */
+int amdgpu_doorbell_alloc_page(struct amdgpu_device *adev,
+                               struct amdgpu_doorbell_obj *db_obj);
+
  #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 1aea92363fd3..8be15b82b545 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c
@@ -111,6 +111,55 @@ void amdgpu_mm_wdoorbell64(struct amdgpu_device *adev, u32 
index, u64 v)
        }
  }
+/**
+ * amdgpu_doorbell_free_page - Free a doorbell page
+ *
+ * @adev: amdgpu_device pointer
+ *
+ * @db_age: previously allocated doobell page details
+ *
+ */
+void amdgpu_doorbell_free_page(struct amdgpu_device *adev,
+                                       struct amdgpu_doorbell_obj *db_obj)
+{
+       amdgpu_bo_free_kernel(&db_obj->bo,
+                             &db_obj->gpu_addr,
+                             (void **)&db_obj->cpu_addr);
+
+}
+
+/**
+ * amdgpu_doorbell_alloc_page - create a page from doorbell pool
+ *
+ * @adev: amdgpu_device pointer
+ *
+ * @db_age: doobell page structure to fill details with
+ *
+ * returns 0 on success, else error number
+ */
+int amdgpu_doorbell_alloc_page(struct amdgpu_device *adev,
+                               struct amdgpu_doorbell_obj *db_obj)
+{
+       int r;
+
+       db_obj->size = ALIGN(db_obj->size, PAGE_SIZE);
+
+       r = amdgpu_bo_create_kernel(adev,
+                                   db_obj->size,
+                                   PAGE_SIZE,
+                                   AMDGPU_GEM_DOMAIN_DOORBELL,
+                                   &db_obj->bo,
+                                   &db_obj->gpu_addr,
+                                   (void **)&db_obj->cpu_addr);
+
+       if (r) {
+               DRM_ERROR("Failed to create doorbell BO, err=%d\n", r);
+               return r;
+       }
+
+       return 0;
+}
+
  /*
   * GPU doorbell aperture helpers function.
   */

Reply via email to