1 files changed, 132 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_query.c b/drivers/gpu/drm/i915/i915_query.c
new file mode 100644
index 000000000..3f502eef2
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_query.c
@@ -0,0 +1,132 @@
+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2018 Intel Corporation
+ */
+
+#include <linux/nospec.h>
+
+#include "i915_drv.h"
+#include "i915_query.h"
+#include <uapi/drm/i915_drm.h>
+
+static int query_topology_info(struct drm_i915_private *dev_priv,
+			       struct drm_i915_query_item *query_item)
+{
+	const struct sseu_dev_info *sseu = &INTEL_INFO(dev_priv)->sseu;
+	struct drm_i915_query_topology_info topo;
+	u32 slice_length, subslice_length, eu_length, total_length;
+
+	if (query_item->flags != 0)
+		return -EINVAL;
+
+	if (sseu->max_slices == 0)
+		return -ENODEV;
+
+	BUILD_BUG_ON(sizeof(u8) != sizeof(sseu->slice_mask));
+
+	slice_length = sizeof(sseu->slice_mask);
+	subslice_length = sseu->max_slices *
+		DIV_ROUND_UP(sseu->max_subslices,
+			     sizeof(sseu->subslice_mask[0]) * BITS_PER_BYTE);
+	eu_length = sseu->max_slices * sseu->max_subslices *
+		DIV_ROUND_UP(sseu->max_eus_per_subslice, BITS_PER_BYTE);
+
+	total_length = sizeof(topo) + slice_length + subslice_length + eu_length;
+
+	if (query_item->length == 0)
+		return total_length;
+
+	if (query_item->length < total_length)
+		return -EINVAL;
+
+	if (copy_from_user(&topo, u64_to_user_ptr(query_item->data_ptr),
+			   sizeof(topo)))
+		return -EFAULT;
+
+	if (topo.flags != 0)
+		return -EINVAL;
+
+	if (!access_ok(VERIFY_WRITE, u64_to_user_ptr(query_item->data_ptr),
+		       total_length))
+		return -EFAULT;
+
+	memset(&topo, 0, sizeof(topo));
+	topo.max_slices = sseu->max_slices;
+	topo.max_subslices = sseu->max_subslices;
+	topo.max_eus_per_subslice = sseu->max_eus_per_subslice;
+
+	topo.subslice_offset = slice_length;
+	topo.subslice_stride = DIV_ROUND_UP(sseu->max_subslices, BITS_PER_BYTE);
+	topo.eu_offset = slice_length + subslice_length;
+	topo.eu_stride =
+		DIV_ROUND_UP(sseu->max_eus_per_subslice, BITS_PER_BYTE);
+
+	if (__copy_to_user(u64_to_user_ptr(query_item->data_ptr),
+			   &topo, sizeof(topo)))
+		return -EFAULT;
+
+	if (__copy_to_user(u64_to_user_ptr(query_item->data_ptr + sizeof(topo)),
+			   &sseu->slice_mask, slice_length))
+		return -EFAULT;
+
+	if (__copy_to_user(u64_to_user_ptr(query_item->data_ptr +
+					   sizeof(topo) + slice_length),
+			   sseu->subslice_mask, subslice_length))
+		return -EFAULT;
+
+	if (__copy_to_user(u64_to_user_ptr(query_item->data_ptr +
+					   sizeof(topo) +
+					   slice_length + subslice_length),
+			   sseu->eu_mask, eu_length))
+		return -EFAULT;
+
+	return total_length;
+}
+
+static int (* const i915_query_funcs[])(struct drm_i915_private *dev_priv,
+					struct drm_i915_query_item *query_item) = {
+	query_topology_info,
+};
+
+int i915_query_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
+{
+	struct drm_i915_private *dev_priv = to_i915(dev);
+	struct drm_i915_query *args = data;
+	struct drm_i915_query_item __user *user_item_ptr =
+		u64_to_user_ptr(args->items_ptr);
+	u32 i;
+
+	if (args->flags != 0)
+		return -EINVAL;
+
+	for (i = 0; i < args->num_items; i++, user_item_ptr++) {
+		struct drm_i915_query_item item;
+		unsigned long func_idx;
+		int ret;
+
+		if (copy_from_user(&item, user_item_ptr, sizeof(item)))
+			return -EFAULT;
+
+		if (item.query_id == 0)
+			return -EINVAL;
+
+		if (overflows_type(item.query_id - 1, unsigned long))
+			return -EINVAL;
+
+		func_idx = item.query_id - 1;
+
+		ret = -EINVAL;
+		if (func_idx < ARRAY_SIZE(i915_query_funcs)) {
+			func_idx = array_index_nospec(func_idx,
+						      ARRAY_SIZE(i915_query_funcs));
+			ret = i915_query_funcs[func_idx](dev_priv, &item);
+		}
+
+		/* Only write the length back to userspace if they differ. */
+		if (ret != item.length && put_user(ret, &user_item_ptr->length))
+			return -EFAULT;
+	}
+
+	return 0;
+}