[Intel-xe] [RFC PATCH 3/3] fixup! drm/xe/display: Implement display support

[Jouni Högander]

Add i915_sw_fence.h compatibility header and implement sw fence
interfaces for display code usage.

Signed-off-by: Jouni Högander <jouni.hogander at intel.com>
---
 .../drm/i915/display/intel_display_types.h    |   1 +
 .../gpu/drm/xe/compat-i915-headers/i915_drv.h |   1 -
 .../xe/compat-i915-headers/i915_sw_fence.h    | 111 ++++++++++++++++++
 3 files changed, 112 insertions(+), 1 deletion(-)
 create mode 100644 drivers/gpu/drm/xe/compat-i915-headers/i915_sw_fence.h

diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index b1141fb125c8..2d11f159f927 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -46,6 +46,7 @@
 #include <drm/i915_hdcp_interface.h>
 #include <media/cec-notifier.h>
 
+#include "i915_sw_fence.h"
 #include "i915_vma.h"
 #include "i915_vma_types.h"
 #include "intel_bios.h"
diff --git a/drivers/gpu/drm/xe/compat-i915-headers/i915_drv.h b/drivers/gpu/drm/xe/compat-i915-headers/i915_drv.h
index 03ac39efba38..c8b0f38e55fa 100644
--- a/drivers/gpu/drm/xe/compat-i915-headers/i915_drv.h
+++ b/drivers/gpu/drm/xe/compat-i915-headers/i915_drv.h
@@ -196,7 +196,6 @@ static inline void intel_runtime_pm_put(struct xe_runtime_pm *pm, bool wakeref)
 #define intel_uncore_forcewake_put(x, y) do { } while (0)
 
 #define intel_uncore_arm_unclaimed_mmio_detection(x) do { } while (0)
-#define i915_sw_fence_commit(x) do { } while (0)
 
 #define with_intel_runtime_pm(rpm, wf) \
 	for ((wf) = intel_runtime_pm_get(rpm); (wf); \
diff --git a/drivers/gpu/drm/xe/compat-i915-headers/i915_sw_fence.h b/drivers/gpu/drm/xe/compat-i915-headers/i915_sw_fence.h
new file mode 100644
index 000000000000..fd6c96682932
--- /dev/null
+++ b/drivers/gpu/drm/xe/compat-i915-headers/i915_sw_fence.h
@@ -0,0 +1,111 @@
+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * i915_sw_fence.h - library routines for N:M synchronisation points
+ *
+ * Copyright (C) 2023 Intel Corporation
+ */
+
+#ifndef _I915_SW_FENCE_H_
+#define _I915_SW_FENCE_H_
+
+#include <linux/dma-fence.h>
+#include <linux/dma-resv.h>
+#include <linux/gfp.h>
+#include <linux/notifier.h> /* for NOTIFY_DONE */
+
+struct completion;
+struct dma_resv;
+struct i915_sw_fence;
+
+enum i915_sw_fence_notify {
+	FENCE_COMPLETE,
+	FENCE_FREE
+};
+
+typedef int (*i915_sw_fence_notify_t)(struct i915_sw_fence *,
+				      enum i915_sw_fence_notify state);
+
+struct i915_sw_fence {
+	struct dma_resv resv;
+	i915_sw_fence_notify_t fn;
+	unsigned long timeout;
+};
+static inline void i915_sw_fence_init(struct i915_sw_fence *fence, i915_sw_fence_notify_t fn)
+{
+	dma_resv_init(&fence->resv);
+	fence->fn = fn;
+	fence->timeout = 0;
+}
+
+static inline void i915_sw_fence_fini(struct i915_sw_fence *fence)
+{
+	dma_resv_fini(&fence->resv);
+}
+
+#define i915_sw_fence_commit(x) do { } while (0)
+
+struct i915_sw_dma_fence_cb {
+	struct dma_fence_cb base;
+	struct i915_sw_fence *fence;
+};
+
+static inline int i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,
+				  struct dma_fence *dma,
+				  unsigned long timeout,
+				  gfp_t gfp)
+{
+	int ret;
+
+	dma_resv_lock(&fence->resv, NULL);
+	ret = dma_resv_reserve_fences(&fence->resv, 1);
+	if (!ret) {
+		dma_resv_add_fence(&fence->resv, dma, dma_resv_usage_rw(false));
+		fence->timeout = max(timeout, fence->timeout);
+	}
+	dma_resv_unlock(&fence->resv);
+
+	return ret;
+}
+
+static inline int i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
+				    struct dma_resv *resv,
+				    bool write,
+				    unsigned long timeout,
+				    gfp_t gfp)
+{
+	struct dma_resv_iter cursor;
+	struct dma_fence *f;
+	int ret;
+
+	dma_resv_iter_begin(&cursor, resv, dma_resv_usage_rw(false));
+	dma_resv_for_each_fence_unlocked(&cursor, f) {
+		ret = i915_sw_fence_await_dma_fence(fence, f, timeout, gfp);
+		if (ret < 0)
+			break;
+	}
+	dma_resv_iter_end(&cursor);
+
+	return ret;
+}
+
+static inline void i915_sw_fence_wait_completion(void *unused,
+						 struct i915_sw_fence *fence)
+{
+	struct dma_resv_iter cursor;
+	struct dma_fence *f;
+
+	dma_resv_wait_timeout(&fence->resv, dma_resv_usage_rw(false),
+			      false, fence->timeout);
+
+	fence->fn(fence, FENCE_COMPLETE);
+
+	dma_resv_iter_begin(&cursor, &fence->resv, dma_resv_usage_rw(false));
+	dma_resv_for_each_fence_unlocked(&cursor, f)
+		dma_fence_put(f);
+	dma_resv_iter_end(&cursor);
+
+	fence->fn(fence, FENCE_FREE);
+}
+
+#endif /* _I915_SW_FENCE_H_ */
-- 
2.34.1