[Intel-gfx] [PATCH 3/3] drm/i915: Expose I915_EXEC_RESOURCE_STREAMER flag

[Abdiel Janulgue]

Ensures that the batch buffer is executed by the resource streamer

v2: Don't skip 1<<15 for the exec flags (Jani Nikula).
    Add I915_PARAM_HAS_RESOURCE_STREAMER to check if kernel has RS support
    baked in (Kenneth Graunke).

Testcase: igt/gem_exec_params
Cc: Jani Nikula <jani.nikula at intel.com>
Cc: kenneth at whitecape.org
Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
Signed-off-by: Abdiel Janulgue <abdiel.janulgue at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_dma.c            |  3 +++
 drivers/gpu/drm/i915/i915_gem_execbuffer.c | 14 ++++++++++++++
 include/uapi/drm/i915_drm.h                |  8 +++++++-
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 68e0c85..10d4ead 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -163,6 +163,9 @@ static int i915_getparam(struct drm_device *dev, void *data,
 		if (!value)
 			return -ENODEV;
 		break;
+	case I915_PARAM_HAS_RESOURCE_STREAMER:
+		value = 1;
+		break;
 	default:
 		DRM_DEBUG("Unknown parameter %d\n", param->param);
 		return -EINVAL;
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index a3190e79..ae064f0 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -1485,6 +1485,20 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
 		return -EINVAL;
 	}
 
+	if (args->flags & I915_EXEC_RESOURCE_STREAMER) {
+		if (!IS_HASWELL(dev) && INTEL_INFO(dev)->gen < 8) {
+			DRM_DEBUG("RS is only allowed for Haswell, Gen8 and above\n");
+			return -EINVAL;
+		}
+		if (ring->id != RCS) {
+			DRM_DEBUG("RS is not available on %s\n",
+				 ring->name);
+			return -EINVAL;
+		}
+
+		dispatch_flags |= I915_DISPATCH_RS;
+	}
+
 	intel_runtime_pm_get(dev_priv);
 
 	ret = i915_mutex_lock_interruptible(dev);
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index 551b673..debccd34 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -350,6 +350,7 @@ typedef struct drm_i915_irq_wait {
 #define I915_PARAM_REVISION              32
 #define I915_PARAM_SUBSLICE_TOTAL	 33
 #define I915_PARAM_EU_TOTAL		 34
+#define I915_PARAM_HAS_RESOURCE_STREAMER 35
 
 typedef struct drm_i915_getparam {
 	int param;
@@ -760,7 +761,12 @@ struct drm_i915_gem_execbuffer2 {
 #define I915_EXEC_BSD_RING1		(1<<13)
 #define I915_EXEC_BSD_RING2		(2<<13)
 
-#define __I915_EXEC_UNKNOWN_FLAGS -(1<<15)
+/** Tell the kernel that the batchbuffer is processed by
+ *  the resource streamer.
+ */
+#define I915_EXEC_RESOURCE_STREAMER     (1<<15)
+
+#define __I915_EXEC_UNKNOWN_FLAGS -(I915_EXEC_RESOURCE_STREAMER<<1)
 
 #define I915_EXEC_CONTEXT_ID_MASK	(0xffffffff)
 #define i915_execbuffer2_set_context_id(eb2, context) \
-- 
1.9.1