drm/i915: Add wrapper for context priority interface

There is an EGL extension to set execution priority per context. This
can be implemented via the i915 per context priority parameter. This
patch adds a wrapper to connect the two together in a way that can be
updated as necessary without breaking one side or the other.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>

3 files changed, 76 insertions, 0 deletions

diff --git a/include/drm/i915_drm.h b/include/drm/i915_drm.h
index c4ce6b2c6f89..8d9f06360942 100644
--- a/include/drm/i915_drm.h
+++ b/include/drm/i915_drm.h
@@ -1167,6 +1167,7 @@ struct drm_i915_gem_context_param {
 #define I915_CONTEXT_PARAM_BAN_PERIOD	0x1
 #define I915_CONTEXT_PARAM_NO_ZEROMAP	0x2
 #define I915_CONTEXT_PARAM_GTT_SIZE	0x3
+#define I915_CONTEXT_PARAM_PRIORITY	0x4
 	__u64 value;
 };
 
diff --git a/intel/intel_bufmgr.h b/intel/intel_bufmgr.h
index a1abbcd2b066..49d41256fd67 100644
--- a/intel/intel_bufmgr.h
+++ b/intel/intel_bufmgr.h
@@ -209,6 +209,11 @@ int drm_intel_gem_bo_wait(drm_intel_bo *bo, int64_t timeout_ns);
 
 drm_intel_context *drm_intel_gem_context_create(drm_intel_bufmgr *bufmgr);
 void drm_intel_gem_context_destroy(drm_intel_context *ctx);
+int drm_intel_gem_context_get_priority(drm_intel_context *ctx, int *priority);
+#define DRM_INTEL_CTX_SET_PRIORITY_EGL_LOW		(0x10001)
+#define DRM_INTEL_CTX_SET_PRIORITY_EGL_MEDIUM		(0x10002)
+#define DRM_INTEL_CTX_SET_PRIORITY_EGL_HIGH		(0x10003)
+int drm_intel_gem_context_set_priority(drm_intel_context *ctx, int priority);
 int drm_intel_gem_bo_context_exec(drm_intel_bo *bo, drm_intel_context *ctx,
 				  int used, unsigned int flags);
 
diff --git a/intel/intel_bufmgr_gem.c b/intel/intel_bufmgr_gem.c
index 0a4012beec58..591ccd5486e7 100644
--- a/intel/intel_bufmgr_gem.c
+++ b/intel/intel_bufmgr_gem.c
@@ -3154,6 +3154,76 @@ drm_intel_gem_context_destroy(drm_intel_context *ctx)
 }
 
 int
+drm_intel_gem_context_get_priority(drm_intel_context *ctx, int *priority)
+{
+	drm_intel_bufmgr_gem *bufmgr_gem;
+	struct drm_i915_gem_context_param ctxparam;
+	int ret;
+
+	if ((ctx == NULL) || (priority == NULL))
+		return -EINVAL;
+
+	memclear(ctxparam);
+
+	bufmgr_gem = (drm_intel_bufmgr_gem *)ctx->bufmgr;
+	ctxparam.ctx_id = ctx->ctx_id;
+	ctxparam.param = I915_CONTEXT_PARAM_PRIORITY;
+	ret = drmIoctl(bufmgr_gem->fd, DRM_IOCTL_I915_GEM_CONTEXT_GETPARAM,
+		       &ctxparam);
+	if (ret != 0) {
+		int err = errno;
+		*priority = 0;
+		fprintf(stderr, "DRM_IOCTL_I915_GEM_CONTEXT_GETPARAM failed: %s\n",
+			strerror(err));
+		return -err;
+	}
+
+	*priority = (int) ctxparam.value;
+
+	return 0;
+}
+
+int
+drm_intel_gem_context_set_priority(drm_intel_context *ctx, int priority)
+{
+	drm_intel_bufmgr_gem *bufmgr_gem;
+	struct drm_i915_gem_context_param ctxparam;
+	int ret;
+
+	if (ctx == NULL)
+		return -EINVAL;
+
+	memclear(ctxparam);
+
+	switch (priority) {
+	case DRM_INTEL_CTX_SET_PRIORITY_EGL_LOW:
+		priority = -500;
+		break;
+	case DRM_INTEL_CTX_SET_PRIORITY_EGL_MEDIUM:
+		priority = -0;
+		break;
+	case DRM_INTEL_CTX_SET_PRIORITY_EGL_HIGH:
+		priority = 500;
+		break;
+	}
+
+	bufmgr_gem = (drm_intel_bufmgr_gem *)ctx->bufmgr;
+	ctxparam.ctx_id = ctx->ctx_id;
+	ctxparam.param = I915_CONTEXT_PARAM_PRIORITY;
+	ctxparam.value = priority;
+	ret = drmIoctl(bufmgr_gem->fd, DRM_IOCTL_I915_GEM_CONTEXT_SETPARAM,
+		       &ctxparam);
+	if (ret != 0) {
+		int err = errno;
+		fprintf(stderr, "DRM_IOCTL_I915_GEM_CONTEXT_SETPARAM failed: %s\n",
+			strerror(err));
+		return -err;
+	}
+
+	return 0;
+}
+
+int
 drm_intel_get_reset_stats(drm_intel_context *ctx,
 			  uint32_t *reset_count,
 			  uint32_t *active,