1 files changed, 94 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_ioctl.c b/drivers/gpu/drm/i915/i915_ioctl.c
new file mode 100644
index 000000000..06a10ccea
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_ioctl.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2022 Intel Corporation
+ */
+
+#include "gt/intel_engine_regs.h"
+
+#include "i915_drv.h"
+#include "i915_gem.h"
+#include "i915_ioctl.h"
+#include "i915_reg.h"
+#include "intel_runtime_pm.h"
+#include "intel_uncore.h"
+
+/*
+ * This file is for small ioctl functions that are out of place everywhere else,
+ * and not big enough to warrant a file of their own.
+ *
+ * This is not the dumping ground for random ioctls.
+ */
+
+struct reg_whitelist {
+	i915_reg_t offset_ldw;
+	i915_reg_t offset_udw;
+	u8 min_graphics_ver;
+	u8 max_graphics_ver;
+	u8 size;
+};
+
+static const struct reg_whitelist reg_read_whitelist[] = {
+	{
+		.offset_ldw = RING_TIMESTAMP(RENDER_RING_BASE),
+		.offset_udw = RING_TIMESTAMP_UDW(RENDER_RING_BASE),
+		.min_graphics_ver = 4,
+		.max_graphics_ver = 12,
+		.size = 8
+	}
+};
+
+int i915_reg_read_ioctl(struct drm_device *dev,
+			void *data, struct drm_file *unused)
+{
+	struct drm_i915_private *i915 = to_i915(dev);
+	struct intel_uncore *uncore = &i915->uncore;
+	struct drm_i915_reg_read *reg = data;
+	struct reg_whitelist const *entry;
+	intel_wakeref_t wakeref;
+	unsigned int flags;
+	int remain;
+	int ret = 0;
+
+	entry = reg_read_whitelist;
+	remain = ARRAY_SIZE(reg_read_whitelist);
+	while (remain) {
+		u32 entry_offset = i915_mmio_reg_offset(entry->offset_ldw);
+
+		GEM_BUG_ON(!is_power_of_2(entry->size));
+		GEM_BUG_ON(entry->size > 8);
+		GEM_BUG_ON(entry_offset & (entry->size - 1));
+
+		if (IS_GRAPHICS_VER(i915, entry->min_graphics_ver, entry->max_graphics_ver) &&
+		    entry_offset == (reg->offset & -entry->size))
+			break;
+		entry++;
+		remain--;
+	}
+
+	if (!remain)
+		return -EINVAL;
+
+	flags = reg->offset & (entry->size - 1);
+
+	with_intel_runtime_pm(&i915->runtime_pm, wakeref) {
+		if (entry->size == 8 && flags == I915_REG_READ_8B_WA)
+			reg->val = intel_uncore_read64_2x32(uncore,
+							    entry->offset_ldw,
+							    entry->offset_udw);
+		else if (entry->size == 8 && flags == 0)
+			reg->val = intel_uncore_read64(uncore,
+						       entry->offset_ldw);
+		else if (entry->size == 4 && flags == 0)
+			reg->val = intel_uncore_read(uncore, entry->offset_ldw);
+		else if (entry->size == 2 && flags == 0)
+			reg->val = intel_uncore_read16(uncore,
+						       entry->offset_ldw);
+		else if (entry->size == 1 && flags == 0)
+			reg->val = intel_uncore_read8(uncore,
+						      entry->offset_ldw);
+		else
+			ret = -EINVAL;
+	}
+
+	return ret;
+}