[PATCH 8/8] drm/amdgpu: DO-NOT-MERGE doorbell hack

[Shashank Sharma]

From: Shashank Sharma <contactshashanksharma at gmail.com>

The doorbell patches, being reviewed here, are requied for Usermode
queues:
https://patchwork.freedesktop.org/series/113669/

This hack patch adds a doorbell IOCTL just to test the usermode
queues functionality, and must not be merged.

Cc: Alex Deucher <alexander.deucher at amd.com>
Cc: Christian König <christian.koenig at amd.com>

Signed-off-by: Shashank Sharma <contactshashanksharma at gmail.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c | 19 +++++++++++++++++++
 include/uapi/drm/amdgpu_drm.h                 |  6 ++++++
 2 files changed, 25 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
index a28ed8e98f7b..b8715dfe27bc 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
@@ -33,6 +33,8 @@ static inline void userqueue_busy_wait(unsigned long ms)
    }
 }
 
+#define AMDGPU_USERQ_DOORBELL_INDEX (AMDGPU_NAVI10_DOORBELL_GFX_USERQUEUE_START + 4)
+
 static inline int
 amdgpu_userqueue_index(struct amdgpu_userq_mgr *uq_mgr, struct amdgpu_usermode_queue *queue)
 {
@@ -208,6 +210,7 @@ static int amdgpu_userqueue_create(struct drm_file *filp, union drm_amdgpu_userq
     queue->queue_gpu_addr = mqd_in->queue_va;
     queue->flags = mqd_in->flags;
     queue->use_doorbell = true;
+    queue->doorbell_index = AMDGPU_USERQ_DOORBELL_INDEX;
     queue->queue_id = amdgpu_userqueue_index(uq_mgr, queue);
     if (queue->queue_id < 0) {
         DRM_ERROR("Failed to allocate a queue id\n");
@@ -276,6 +279,22 @@ static void amdgpu_userqueue_destroy(struct drm_file *filp, int queue_id)
     kfree(queue);
 }
 
+int amdgpu_userq_doorbell_ring_ioctl(struct drm_device *dev, void *data,
+		       struct drm_file *filp)
+{
+    struct drm_amdgpu_db_ring *in = data;
+    struct amdgpu_fpriv *fpriv = filp->driver_priv;
+    struct amdgpu_userq_mgr *uq_mgr = &fpriv->userq_mgr;
+    struct amdgpu_device *adev = uq_mgr->adev;
+
+    mutex_lock(&uq_mgr->userq_mutex);
+    WDOORBELL32(AMDGPU_USERQ_DOORBELL_INDEX, in->val);
+    mutex_unlock(&uq_mgr->userq_mutex);
+
+    DRM_DEBUG_DRIVER("Doorbell rung\n");
+    return 0;
+}
+
 int amdgpu_userq_ioctl(struct drm_device *dev, void *data,
 		       struct drm_file *filp)
 {
diff --git a/include/uapi/drm/amdgpu_drm.h b/include/uapi/drm/amdgpu_drm.h
index 6c5235d107b3..2d94cca566e0 100644
--- a/include/uapi/drm/amdgpu_drm.h
+++ b/include/uapi/drm/amdgpu_drm.h
@@ -55,6 +55,7 @@ extern "C" {
 #define DRM_AMDGPU_FENCE_TO_HANDLE	0x14
 #define DRM_AMDGPU_SCHED		0x15
 #define DRM_AMDGPU_USERQ		0x16
+#define DRM_AMDGPU_USERQ_DOORBELL_RING		0x17
 
 #define DRM_IOCTL_AMDGPU_GEM_CREATE	DRM_IOWR(DRM_COMMAND_BASE + DRM_AMDGPU_GEM_CREATE, union drm_amdgpu_gem_create)
 #define DRM_IOCTL_AMDGPU_GEM_MMAP	DRM_IOWR(DRM_COMMAND_BASE + DRM_AMDGPU_GEM_MMAP, union drm_amdgpu_gem_mmap)
@@ -73,6 +74,7 @@ extern "C" {
 #define DRM_IOCTL_AMDGPU_FENCE_TO_HANDLE DRM_IOWR(DRM_COMMAND_BASE + DRM_AMDGPU_FENCE_TO_HANDLE, union drm_amdgpu_fence_to_handle)
 #define DRM_IOCTL_AMDGPU_SCHED		DRM_IOW(DRM_COMMAND_BASE + DRM_AMDGPU_SCHED, union drm_amdgpu_sched)
 #define DRM_IOCTL_AMDGPU_USERQ		DRM_IOW(DRM_COMMAND_BASE + DRM_AMDGPU_USERQ, union drm_amdgpu_userq)
+#define DRM_IOCTL_AMDGPU_USERQ_DOORBELL_RING		DRM_IOW(DRM_COMMAND_BASE + DRM_AMDGPU_USERQ_DOORBELL_RING, struct drm_amdgpu_db_ring)
 
 /**
  * DOC: memory domains
@@ -350,6 +352,10 @@ struct drm_amdgpu_userq_out {
 	__u32	flags;
 };
 
+struct drm_amdgpu_db_ring {
+	__u64 val;
+};
+
 union drm_amdgpu_userq {
 	struct drm_amdgpu_userq_in in;
 	struct drm_amdgpu_userq_out out;
-- 
2.34.1