[Intel-gfx] [PATCH 1/2] drm/i915: Slice/Subslice/EU info via GETPARAM

[jeff.mcgee at intel.com]

From: Jeff McGee <jeff.mcgee at intel.com>

Define a struct to capture information on the device's Slice/Subslice/EU
(SSEU) configuration. Add this struct to the main device info struct.
Define a packed bitfield form for the SSEU info and share it with
userspace via a new GETPARAM option.

Starting with Cherryview, devices may have a varying number of EU for
a given ID due to creative fusing. The surest way to determine the
configuration is by reading fuses which is best done in the kernel and
communicated to userspace. The immediate need from userspace is to
determine the number of threads of compute work that can be safely
submitted.

The definition of SSEU as a new drm/i915 component, with its own header
file and soon-to-be source file, is in anticipation of lots of upcoming
code for its management, particularly the power gating functionality.

Signed-off-by: Jeff McGee <jeff.mcgee at intel.com>
---
 drivers/gpu/drm/i915/i915_dma.c   |  3 +++
 drivers/gpu/drm/i915/i915_drv.h   |  3 +++
 drivers/gpu/drm/i915/intel_sseu.h | 40 +++++++++++++++++++++++++++++++++++++++
 include/uapi/drm/i915_drm.h       | 18 ++++++++++++++++++
 4 files changed, 64 insertions(+)
 create mode 100644 drivers/gpu/drm/i915/intel_sseu.h

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 2e7f03a..f581848 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1025,6 +1025,9 @@ static int i915_getparam(struct drm_device *dev, void *data,
 	case I915_PARAM_CMD_PARSER_VERSION:
 		value = i915_cmd_parser_get_version();
 		break;
+	case I915_PARAM_SSEU_INFO:
+		value = INTEL_INFO(dev)->sseu.gp_sseu_info;
+		break;
 	default:
 		DRM_DEBUG("Unknown parameter %d\n", param->param);
 		return -EINVAL;
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 18c9ad8..01adafd 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -45,6 +45,7 @@
 #include <linux/intel-iommu.h>
 #include <linux/kref.h>
 #include <linux/pm_qos.h>
+#include "intel_sseu.h"
 
 /* General customization:
  */
@@ -562,6 +563,8 @@ struct intel_device_info {
 	int trans_offsets[I915_MAX_TRANSCODERS];
 	int palette_offsets[I915_MAX_PIPES];
 	int cursor_offsets[I915_MAX_PIPES];
+	/* Slice/Subslice/EU info */
+	struct intel_sseu_info sseu;
 };
 
 #undef DEFINE_FLAG
diff --git a/drivers/gpu/drm/i915/intel_sseu.h b/drivers/gpu/drm/i915/intel_sseu.h
new file mode 100644
index 0000000..7db7175
--- /dev/null
+++ b/drivers/gpu/drm/i915/intel_sseu.h
@@ -0,0 +1,40 @@
+/*
+ * Copyright © 2014 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.
+ *
+ */
+#ifndef _INTEL_SSEU_H_
+#define _INTEL_SSEU_H_
+
+struct intel_sseu_info {
+	/* Total slice count */
+	unsigned int slice_cnt;
+	/* Total subslice count */
+	unsigned int subslice_cnt;
+	/* Total execution unit count */
+	unsigned int eu_cnt;
+	/* Thread count per EU */
+	unsigned int threads_per_eu;
+	/* Bit field representation for I915_PARAM_SSEU_INFO */
+	u32 gp_sseu_info;
+};
+
+#endif
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index ff57f07..b99c1a2 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -171,6 +171,23 @@ typedef struct _drm_i915_sarea {
 #define I915_BOX_TEXTURE_LOAD  0x8
 #define I915_BOX_LOST_CONTEXT  0x10
 
+/*
+ * Slice/Subslice/EU Info
+ * - Accessed via GETPARAM ioctl option I915_PARAM_SSEU_INFO
+ * - SLICE_CNT: total slice count
+ * - SUBSLICE_CNT: total subslice count
+ * - EU_CNT: total execution unit count
+ * - THREADS_PER_EU: thread count per EU
+*/
+#define I915_SSEU_INFO_SLICE_CNT_MASK		0xf
+#define I915_SSEU_INFO_SLICE_CNT_SHIFT		0
+#define I915_SSEU_INFO_SUBSLICE_CNT_MASK	(0x3f<<4)
+#define I915_SSEU_INFO_SUBSLICE_CNT_SHIFT	4
+#define I915_SSEU_INFO_EU_CNT_MASK		(0xff<<10)
+#define I915_SSEU_INFO_EU_CNT_SHIFT		10
+#define I915_SSEU_INFO_THREADS_PER_EU_MASK	(0xf<<18)
+#define I915_SSEU_INFO_THREADS_PER_EU_SHIFT	18
+
 /* I915 specific ioctls
  * The device specific ioctl range is 0x40 to 0x79.
  */
@@ -340,6 +357,7 @@ typedef struct drm_i915_irq_wait {
 #define I915_PARAM_HAS_EXEC_HANDLE_LUT   26
 #define I915_PARAM_HAS_WT     	 	 27
 #define I915_PARAM_CMD_PARSER_VERSION	 28
+#define I915_PARAM_SSEU_INFO		 29
 
 typedef struct drm_i915_getparam {
 	int param;
-- 
2.0.1