[PATCH libdrm 2/2] amdgpu: implement context priority for amdgpu_cs_ctx_create2 v3

[Andres Rodriguez]

Add a new context creation function that allows specifying the context
priority.

A high priority context has the potential of starving lower priority
contexts. The current kernel driver implementation allows only apps
that hold CAP_SYS_NICE or DRM_MASTER to acquire a priority above
AMDGPU_CTX_PRIORITY_NORMAL.

v2: corresponding changes for kernel patch v2
v3: Fixed 'make check' symbol error

Signed-off-by: Andres Rodriguez <andresx7 at gmail.com>
---
 amdgpu/amdgpu-symbol-check |  1 +
 amdgpu/amdgpu.h            | 17 +++++++++++++++--
 amdgpu/amdgpu_cs.c         | 17 +++++++++++++----
 3 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/amdgpu/amdgpu-symbol-check b/amdgpu/amdgpu-symbol-check
index d9f89ef..095c3a0 100755
--- a/amdgpu/amdgpu-symbol-check
+++ b/amdgpu/amdgpu-symbol-check
@@ -30,6 +30,7 @@ amdgpu_cs_chunk_fence_to_dep
 amdgpu_cs_create_semaphore
 amdgpu_cs_create_syncobj
 amdgpu_cs_ctx_create
+amdgpu_cs_ctx_create2
 amdgpu_cs_ctx_free
 amdgpu_cs_destroy_semaphore
 amdgpu_cs_destroy_syncobj
diff --git a/amdgpu/amdgpu.h b/amdgpu/amdgpu.h
index 23cde10..ecc975f 100644
--- a/amdgpu/amdgpu.h
+++ b/amdgpu/amdgpu.h
@@ -798,8 +798,9 @@ int amdgpu_bo_list_update(amdgpu_bo_list_handle handle,
  * context will always be executed in order (first come, first serve).
  *
  *
- * \param   dev	    - \c [in] Device handle. See #amdgpu_device_initialize()
- * \param   context - \c [out] GPU Context handle
+ * \param   dev      - \c [in] Device handle. See #amdgpu_device_initialize()
+ * \param   priority - \c [in] Context creation flags. See AMDGPU_CTX_PRIORITY_*
+ * \param   context  - \c [out] GPU Context handle
  *
  * \return   0 on success\n
  *          <0 - Negative POSIX Error code
@@ -807,6 +808,18 @@ int amdgpu_bo_list_update(amdgpu_bo_list_handle handle,
  * \sa amdgpu_cs_ctx_free()
  *
 */
+int amdgpu_cs_ctx_create2(amdgpu_device_handle dev,
+			 uint32_t priority,
+			 amdgpu_context_handle *context);
+/**
+ * Create GPU execution Context
+ *
+ * Refer to amdgpu_cs_ctx_create2 for full documentation. This call
+ * is missing the priority parameter.
+ *
+ * \sa amdgpu_cs_ctx_create2()
+ *
+*/
 int amdgpu_cs_ctx_create(amdgpu_device_handle dev,
 			 amdgpu_context_handle *context);
 
diff --git a/amdgpu/amdgpu_cs.c b/amdgpu/amdgpu_cs.c
index 9577d5c..b9fc01e 100644
--- a/amdgpu/amdgpu_cs.c
+++ b/amdgpu/amdgpu_cs.c
@@ -46,13 +46,14 @@ static int amdgpu_cs_reset_sem(amdgpu_semaphore_handle sem);
 /**
  * Create command submission context
  *
- * \param   dev - \c [in] amdgpu device handle
- * \param   context - \c [out] amdgpu context handle
+ * \param   dev      - \c [in] Device handle. See #amdgpu_device_initialize()
+ * \param   priority - \c [in] Context creation flags. See AMDGPU_CTX_PRIORITY_*
+ * \param   context  - \c [out] GPU Context handle
  *
  * \return  0 on success otherwise POSIX Error code
 */
-int amdgpu_cs_ctx_create(amdgpu_device_handle dev,
-			 amdgpu_context_handle *context)
+int amdgpu_cs_ctx_create2(amdgpu_device_handle dev, uint32_t priority,
+							amdgpu_context_handle *context)
 {
 	struct amdgpu_context *gpu_context;
 	union drm_amdgpu_ctx args;
@@ -75,6 +76,8 @@ int amdgpu_cs_ctx_create(amdgpu_device_handle dev,
 	/* Create the context */
 	memset(&args, 0, sizeof(args));
 	args.in.op = AMDGPU_CTX_OP_ALLOC_CTX;
+	args.in.priority = priority;
+
 	r = drmCommandWriteRead(dev->fd, DRM_AMDGPU_CTX, &args, sizeof(args));
 	if (r)
 		goto error;
@@ -94,6 +97,12 @@ error:
 	return r;
 }
 
+int amdgpu_cs_ctx_create(amdgpu_device_handle dev,
+			 amdgpu_context_handle *context)
+{
+	return amdgpu_cs_ctx_create2(dev, AMDGPU_CTX_PRIORITY_NORMAL, context);
+}
+
 /**
  * Release command submission context
  *
-- 
2.9.3