[Intel-gfx] [PATCH 1/1] drm/i915/uapi: Enable L3 Bank Count Querying

[Jonathan Cavitt <jonathan.cavitt@intel.com>]

Extend the query ioctl to allow querying the count of the available L3
Banks on a given engine.

Signed-off-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
---
 drivers/gpu/drm/i915/gt/intel_gt.c      | 26 +++++++++++++++++++
 drivers/gpu/drm/i915/gt/intel_gt.h      |  3 +++
 drivers/gpu/drm/i915/gt/intel_gt_regs.h |  1 +
 drivers/gpu/drm/i915/i915_query.c       | 34 +++++++++++++++++++++++++
 include/uapi/drm/i915_drm.h             | 15 ++++++++++-
 5 files changed, 78 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c
index 449f0b7fc8434..865854c76c375 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt.c
@@ -884,6 +884,32 @@ static int intel_gt_tile_setup(struct intel_gt *gt, phys_addr_t phys_addr)
 	return 0;
 }
 
+int intel_count_l3_banks(struct drm_i915_private *i915,
+			 struct intel_engine_cs *engine)
+{
+	struct intel_gt *gt = engine->gt;
+	struct intel_uncore *uncore = gt->uncore;
+	intel_wakeref_t wakeref;
+	u32 count, store;
+
+	/* L3 Banks not supported prior to version 12 */
+	if (GRAPHICS_VER(i915) < 12)
+		return -ENODEV;
+
+	if (IS_PONTEVECCHIO(i915)) {
+		with_intel_runtime_pm(uncore->rpm, wakeref)
+			store = intel_uncore_read(uncore, GEN10_MIRROR_FUSE3);
+		count = hweight32(REG_FIELD_GET(GEN12_MEML3_EN_MASK, store)) * 4 *
+			hweight32(REG_FIELD_GET(XEHPC_GT_L3_MODE_MASK, store));
+	} else if (GRAPHICS_VER_FULL(i915) > IP_VER(12, 50)) {
+		count = hweight32(gt->info.mslice_mask) * 8;
+	} else {
+		count = hweight32(gt->info.l3bank_mask);
+	}
+
+	return count;
+}
+
 int intel_gt_probe_all(struct drm_i915_private *i915)
 {
 	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
diff --git a/drivers/gpu/drm/i915/gt/intel_gt.h b/drivers/gpu/drm/i915/gt/intel_gt.h
index 239848bcb2a42..4a05443418efd 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt.h
+++ b/drivers/gpu/drm/i915/gt/intel_gt.h
@@ -161,6 +161,9 @@ static inline bool intel_gt_is_wedged(const struct intel_gt *gt)
 	return unlikely(test_bit(I915_WEDGED, &gt->reset.flags));
 }
 
+int intel_count_l3_banks(struct drm_i915_private *i915,
+			 struct intel_engine_cs *engine);
+
 int intel_gt_probe_all(struct drm_i915_private *i915);
 int intel_gt_tiles_init(struct drm_i915_private *i915);
 void intel_gt_release_all(struct drm_i915_private *i915);
diff --git a/drivers/gpu/drm/i915/gt/intel_gt_regs.h b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
index a00ff51c681d5..f148bf3dfd4b3 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_regs.h
+++ b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
@@ -569,6 +569,7 @@
 #define	GEN10_MIRROR_FUSE3			_MMIO(0x9118)
 #define   GEN10_L3BANK_PAIR_COUNT		4
 #define   GEN10_L3BANK_MASK			0x0F
+#define   XEHPC_GT_L3_MODE_MASK			REG_GENMASK(7, 4)
 /* on Xe_HP the same fuses indicates mslices instead of L3 banks */
 #define   GEN12_MAX_MSLICES			4
 #define   GEN12_MEML3_EN_MASK			0x0F
diff --git a/drivers/gpu/drm/i915/i915_query.c b/drivers/gpu/drm/i915/i915_query.c
index 00871ef997920..bd3e68cf1bd10 100644
--- a/drivers/gpu/drm/i915/i915_query.c
+++ b/drivers/gpu/drm/i915/i915_query.c
@@ -10,6 +10,7 @@
 #include "i915_perf.h"
 #include "i915_query.h"
 #include "gt/intel_engine_user.h"
+#include "gt/intel_gt.h"
 #include <uapi/drm/i915_drm.h>
 
 static int copy_query_item(void *query_hdr, size_t query_sz,
@@ -551,6 +552,38 @@ static int query_hwconfig_blob(struct drm_i915_private *i915,
 	return hwconfig->size;
 }
 
+static int
+query_l3bank_count(struct drm_i915_private *i915,
+		   struct drm_i915_query_item *query_item)
+{
+	struct drm_i915_query_memory_regions __user *query_ptr =
+		u64_to_user_ptr(query_item->data_ptr);
+	struct i915_engine_class_instance classinstance;
+	struct intel_engine_cs *engine;
+	int count;
+
+	if (query_item->length == 0)
+		return sizeof(count);
+
+	classinstance = *((struct i915_engine_class_instance *)&query_item->flags);
+
+	engine = intel_engine_lookup_user(i915, (u8)classinstance.engine_class,
+					  (u8)classinstance.engine_instance);
+
+	if (!engine)
+		return -EINVAL;
+
+	count = intel_count_l3_banks(i915, engine);
+
+	if (count < 0)
+		return count;
+
+	if (copy_to_user(query_ptr, &count, sizeof(count)))
+		return -EFAULT;
+
+	return sizeof(count);
+}
+
 static int (* const i915_query_funcs[])(struct drm_i915_private *dev_priv,
 					struct drm_i915_query_item *query_item) = {
 	query_topology_info,
@@ -559,6 +592,7 @@ static int (* const i915_query_funcs[])(struct drm_i915_private *dev_priv,
 	query_memregion_info,
 	query_hwconfig_blob,
 	query_geometry_subslices,
+	query_l3bank_count,
 };
 
 int i915_query_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index 7000e5910a1d7..746d427af8e4c 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -3013,6 +3013,7 @@ struct drm_i915_query_item {
 	 *  - %DRM_I915_QUERY_MEMORY_REGIONS (see struct drm_i915_query_memory_regions)
 	 *  - %DRM_I915_QUERY_HWCONFIG_BLOB (see `GuC HWCONFIG blob uAPI`)
 	 *  - %DRM_I915_QUERY_GEOMETRY_SUBSLICES (see struct drm_i915_query_topology_info)
+	 *  - %DRM_I915_QUERY_L3BANK_COUNT (see `L3 Bank Count Query uAPI`)
 	 */
 	__u64 query_id;
 #define DRM_I915_QUERY_TOPOLOGY_INFO		1
@@ -3021,6 +3022,7 @@ struct drm_i915_query_item {
 #define DRM_I915_QUERY_MEMORY_REGIONS		4
 #define DRM_I915_QUERY_HWCONFIG_BLOB		5
 #define DRM_I915_QUERY_GEOMETRY_SUBSLICES	6
+#define DRM_I915_QUERY_L3BANK_COUNT		7
 /* Must be kept compact -- no holes and well documented */
 
 	/**
@@ -3443,7 +3445,7 @@ struct drm_i915_memory_region_info {
 	__u64 probed_size;
 
 	/**
-	 * @unallocated_size: Estimate of memory remaining
+.	 * @unallocated_size: Estimate of memory remaining
 	 *
 	 * Requires CAP_PERFMON or CAP_SYS_ADMIN to get reliable accounting.
 	 * Without this (or if this is an older kernel) the value here will
@@ -3690,6 +3692,17 @@ struct drm_i915_gem_create_ext {
 	__u64 extensions;
 };
 
+/**
+ * DOC: L3 Bank Count Query uAPI
+ *
+ * The L3 bank count query called through the query id
+ * DRM_I915_QUERY_L3BANK_COUNT and returns the count of
+ * the available L3 Banks on a given engine.
+ *
+ * The count itself is an integer, and since no additional
+ * data is returned, the count is returned as such.
+ */
+
 /**
  * struct drm_i915_gem_create_ext_memory_regions - The
  * I915_GEM_CREATE_EXT_MEMORY_REGIONS extension.
-- 
2.25.1