[Intel-gfx] [PATCH 02/18] drm/i915: preliminary context support

Ben Widawsky ben at bwidawsk.net
Sun Mar 18 21:39:42 CET 2012


Very basic code for context setup/destruction in the driver.

There are 4 entry points into the contexts, load, unload, open, close.
The names are self-explanatory except that load can be called during
reset, and also during pm thaw/resume. As we expect our context to be
preserved across these events, we do not reinitialize in this case.

Also an important note, as I intend to use contexts for ILK RC6, the
context initialization must always come before RC6 initialization.

As Adam Jackson pointed out, I picked an arbitrary cutoff of 1MB where I
decide the HW context is too big. The reason for this is even though
context sizes are increasing with every generation, they are still
measured in pages. If we somehow read back way more than that, it
probably means BIOS has done something strange, or we're running on a
platform that wasn't designed for this.

The 1MB was just a nice round number. I'm open to changing it to
something sensible if someone has a better idea.

Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
---
 drivers/gpu/drm/i915/Makefile           |    1 +
 drivers/gpu/drm/i915/i915_dma.c         |    4 ++
 drivers/gpu/drm/i915/i915_drv.c         |    1 +
 drivers/gpu/drm/i915/i915_drv.h         |    9 +++
 drivers/gpu/drm/i915/i915_gem.c         |    1 +
 drivers/gpu/drm/i915/i915_gem_context.c |  114 +++++++++++++++++++++++++++++++
 6 files changed, 130 insertions(+)
 create mode 100644 drivers/gpu/drm/i915/i915_gem_context.c

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index ce7fc77..a625d30 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -7,6 +7,7 @@ i915-y := i915_drv.o i915_dma.o i915_irq.o \
 	  i915_debugfs.o \
           i915_suspend.o \
 	  i915_gem.o \
+	  i915_gem_context.o \
 	  i915_gem_debug.o \
 	  i915_gem_evict.o \
 	  i915_gem_execbuffer.o \
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 9341eb8..4c7c1dc 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -2155,6 +2155,7 @@ int i915_driver_unload(struct drm_device *dev)
 	ret = i915_gpu_idle(dev, true);
 	if (ret)
 		DRM_ERROR("failed to idle hardware: %d\n", ret);
+	i915_gem_context_unload(dev);
 	mutex_unlock(&dev->struct_mutex);
 
 	/* Cancel the retire work handler, which should be idle now. */
@@ -2244,6 +2245,8 @@ int i915_driver_open(struct drm_device *dev, struct drm_file *file)
 	spin_lock_init(&file_priv->mm.lock);
 	INIT_LIST_HEAD(&file_priv->mm.request_list);
 
+	i915_gem_context_open(dev, file);
+
 	return 0;
 }
 
@@ -2276,6 +2279,7 @@ void i915_driver_lastclose(struct drm_device * dev)
 
 void i915_driver_preclose(struct drm_device * dev, struct drm_file *file_priv)
 {
+	i915_gem_context_close(dev, file_priv);
 	i915_gem_release(dev, file_priv);
 }
 
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 0694e17..b2c56db 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -742,6 +742,7 @@ int i915_reset(struct drm_device *dev, u8 flags)
 		if (HAS_BLT(dev))
 		    dev_priv->ring[BCS].init(&dev_priv->ring[BCS]);
 
+		i915_gem_context_load(dev);
 		i915_gem_init_ppgtt(dev);
 
 		mutex_unlock(&dev->struct_mutex);
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index c0f19f5..33c232a 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -779,6 +779,9 @@ typedef struct drm_i915_private {
 
 	struct drm_property *broadcast_rgb_property;
 	struct drm_property *force_audio_property;
+
+	bool hw_contexts_disabled;
+	uint32_t hw_context_size;
 } drm_i915_private_t;
 
 enum hdmi_force_audio {
@@ -1280,6 +1283,12 @@ i915_gem_get_unfenced_gtt_alignment(struct drm_device *dev,
 int i915_gem_object_set_cache_level(struct drm_i915_gem_object *obj,
 				    enum i915_cache_level cache_level);
 
+/* i915_gem_context.c */
+void i915_gem_context_load(struct drm_device *dev);
+void i915_gem_context_unload(struct drm_device *dev);
+void i915_gem_context_open(struct drm_device *dev, struct drm_file *file);
+void i915_gem_context_close(struct drm_device *dev, struct drm_file *file);
+
 /* i915_gem_gtt.c */
 int __must_check i915_gem_init_aliasing_ppgtt(struct drm_device *dev);
 void i915_gem_cleanup_aliasing_ppgtt(struct drm_device *dev);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 1f441f5..6343a82 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3811,6 +3811,7 @@ i915_gem_init_hw(struct drm_device *dev)
 
 	dev_priv->next_seqno = 1;
 
+	i915_gem_context_load(dev);
 	i915_gem_init_ppgtt(dev);
 
 	return 0;
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
new file mode 100644
index 0000000..caa0e06
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -0,0 +1,114 @@
+/*
+ * Copyright © 2012 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * Authors:
+ *    Ben Widawsky <ben at bwidawsk.net>
+ *
+ */
+
+#include "drmP.h"
+#include "i915_drm.h"
+#include "i915_drv.h"
+
+static int get_context_size(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	int ret;
+	u32 reg;
+
+	/* Context size (as of gen7) is determined in number of cache lines */
+	switch (INTEL_INFO(dev)->gen) {
+	case 5: /* ILK & SNB have the same context reg layout */
+	case 6:
+		reg = I915_READ(CXT_SIZE);
+		ret = GEN6_CXT_TOTAL_SIZE(reg) * 64;
+		break;
+	case 7:
+		reg = I915_READ(GEN7_CTX_SIZE);
+		ret = GEN7_CTX_TOTAL_SIZE(reg) * 64;
+		break;
+	default:
+		ret = -1;
+	}
+
+	return ret;
+}
+
+/**
+ * The default context needs to exist per ring that uses contexts. It stores the
+ * context state of the GPU for applications that don't utilize HW contexts, as
+ * well as an idle case.
+ */
+static int create_default_context(struct drm_i915_private *dev_priv)
+{
+	return 0;
+}
+
+void i915_gem_context_load(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	uint32_t ctx_size;
+
+	/* If called from reset, or thaw... we've been here already */
+	if (dev_priv->hw_contexts_disabled)
+		return;
+
+	ctx_size = get_context_size(dev);
+	dev_priv->hw_context_size = get_context_size(dev);
+	dev_priv->hw_context_size = round_up(dev_priv->hw_context_size, 4096);
+
+	if (ctx_size <= 0 || ctx_size > (1<<20)) {
+		dev_priv->hw_contexts_disabled = true;
+		return;
+	}
+
+	if (create_default_context(dev_priv)) {
+		dev_priv->hw_contexts_disabled = true;
+		return;
+	}
+
+	DRM_DEBUG_DRIVER("HW context support initialized\n");
+}
+
+void i915_gem_context_unload(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	if (dev_priv->hw_contexts_disabled)
+		return;
+}
+
+void i915_gem_context_open(struct drm_device *dev, struct drm_file *file)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	if (dev_priv->hw_contexts_disabled)
+		return;
+}
+
+void i915_gem_context_close(struct drm_device *dev, struct drm_file *file)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	if (dev_priv->hw_contexts_disabled)
+		return;
+}
-- 
1.7.9.4




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