1 files changed, 230 insertions, 0 deletions
diff --git a/drivers/gpu/drm/xe/xe_hw_fence.c b/drivers/gpu/drm/xe/xe_hw_fence.c
new file mode 100644
index 000000000000..e56ca2867545
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_hw_fence.c
@@ -0,0 +1,230 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2021 Intel Corporation
+ */
+
+#include "xe_hw_fence.h"
+
+#include <linux/device.h>
+#include <linux/slab.h>
+
+#include "xe_bo.h"
+#include "xe_device.h"
+#include "xe_gt.h"
+#include "xe_hw_engine.h"
+#include "xe_macros.h"
+#include "xe_map.h"
+#include "xe_trace.h"
+
+static struct kmem_cache *xe_hw_fence_slab;
+
+int __init xe_hw_fence_module_init(void)
+{
+	xe_hw_fence_slab = kmem_cache_create("xe_hw_fence",
+					     sizeof(struct xe_hw_fence), 0,
+					     SLAB_HWCACHE_ALIGN, NULL);
+	if (!xe_hw_fence_slab)
+		return -ENOMEM;
+
+	return 0;
+}
+
+void xe_hw_fence_module_exit(void)
+{
+	rcu_barrier();
+	kmem_cache_destroy(xe_hw_fence_slab);
+}
+
+static struct xe_hw_fence *fence_alloc(void)
+{
+	return kmem_cache_zalloc(xe_hw_fence_slab, GFP_KERNEL);
+}
+
+static void fence_free(struct rcu_head *rcu)
+{
+	struct xe_hw_fence *fence =
+		container_of(rcu, struct xe_hw_fence, dma.rcu);
+
+	if (!WARN_ON_ONCE(!fence))
+		kmem_cache_free(xe_hw_fence_slab, fence);
+}
+
+static void hw_fence_irq_run_cb(struct irq_work *work)
+{
+	struct xe_hw_fence_irq *irq = container_of(work, typeof(*irq), work);
+	struct xe_hw_fence *fence, *next;
+	bool tmp;
+
+	tmp = dma_fence_begin_signalling();
+	spin_lock(&irq->lock);
+	if (irq->enabled) {
+		list_for_each_entry_safe(fence, next, &irq->pending, irq_link) {
+			struct dma_fence *dma_fence = &fence->dma;
+
+			trace_xe_hw_fence_try_signal(fence);
+			if (dma_fence_is_signaled_locked(dma_fence)) {
+				trace_xe_hw_fence_signal(fence);
+				list_del_init(&fence->irq_link);
+				dma_fence_put(dma_fence);
+			}
+		}
+	}
+	spin_unlock(&irq->lock);
+	dma_fence_end_signalling(tmp);
+}
+
+void xe_hw_fence_irq_init(struct xe_hw_fence_irq *irq)
+{
+	spin_lock_init(&irq->lock);
+	init_irq_work(&irq->work, hw_fence_irq_run_cb);
+	INIT_LIST_HEAD(&irq->pending);
+	irq->enabled = true;
+}
+
+void xe_hw_fence_irq_finish(struct xe_hw_fence_irq *irq)
+{
+	struct xe_hw_fence *fence, *next;
+	unsigned long flags;
+	int err;
+	bool tmp;
+
+	if (XE_WARN_ON(!list_empty(&irq->pending))) {
+		tmp = dma_fence_begin_signalling();
+		spin_lock_irqsave(&irq->lock, flags);
+		list_for_each_entry_safe(fence, next, &irq->pending, irq_link) {
+			list_del_init(&fence->irq_link);
+			err = dma_fence_signal_locked(&fence->dma);
+			dma_fence_put(&fence->dma);
+			XE_WARN_ON(err);
+		}
+		spin_unlock_irqrestore(&irq->lock, flags);
+		dma_fence_end_signalling(tmp);
+	}
+}
+
+void xe_hw_fence_irq_run(struct xe_hw_fence_irq *irq)
+{
+	irq_work_queue(&irq->work);
+}
+
+void xe_hw_fence_irq_stop(struct xe_hw_fence_irq *irq)
+{
+	spin_lock_irq(&irq->lock);
+	irq->enabled = false;
+	spin_unlock_irq(&irq->lock);
+}
+
+void xe_hw_fence_irq_start(struct xe_hw_fence_irq *irq)
+{
+	spin_lock_irq(&irq->lock);
+	irq->enabled = true;
+	spin_unlock_irq(&irq->lock);
+
+	irq_work_queue(&irq->work);
+}
+
+void xe_hw_fence_ctx_init(struct xe_hw_fence_ctx *ctx, struct xe_gt *gt,
+			  struct xe_hw_fence_irq *irq, const char *name)
+{
+	ctx->gt = gt;
+	ctx->irq = irq;
+	ctx->dma_fence_ctx = dma_fence_context_alloc(1);
+	ctx->next_seqno = 1;
+	sprintf(ctx->name, "%s", name);
+}
+
+void xe_hw_fence_ctx_finish(struct xe_hw_fence_ctx *ctx)
+{
+}
+
+static struct xe_hw_fence *to_xe_hw_fence(struct dma_fence *fence);
+
+static struct xe_hw_fence_irq *xe_hw_fence_irq(struct xe_hw_fence *fence)
+{
+	return container_of(fence->dma.lock, struct xe_hw_fence_irq, lock);
+}
+
+static const char *xe_hw_fence_get_driver_name(struct dma_fence *dma_fence)
+{
+	struct xe_hw_fence *fence = to_xe_hw_fence(dma_fence);
+
+	return dev_name(gt_to_xe(fence->ctx->gt)->drm.dev);
+}
+
+static const char *xe_hw_fence_get_timeline_name(struct dma_fence *dma_fence)
+{
+	struct xe_hw_fence *fence = to_xe_hw_fence(dma_fence);
+
+	return fence->ctx->name;
+}
+
+static bool xe_hw_fence_signaled(struct dma_fence *dma_fence)
+{
+	struct xe_hw_fence *fence = to_xe_hw_fence(dma_fence);
+	struct xe_device *xe = gt_to_xe(fence->ctx->gt);
+	u32 seqno = xe_map_rd(xe, &fence->seqno_map, 0, u32);
+
+	return dma_fence->error ||
+		(s32)fence->dma.seqno <= (s32)seqno;
+}
+
+static bool xe_hw_fence_enable_signaling(struct dma_fence *dma_fence)
+{
+	struct xe_hw_fence *fence = to_xe_hw_fence(dma_fence);
+	struct xe_hw_fence_irq *irq = xe_hw_fence_irq(fence);
+
+	dma_fence_get(dma_fence);
+	list_add_tail(&fence->irq_link, &irq->pending);
+
+	/* SW completed (no HW IRQ) so kick handler to signal fence */
+	if (xe_hw_fence_signaled(dma_fence))
+		xe_hw_fence_irq_run(irq);
+
+	return true;
+}
+
+static void xe_hw_fence_release(struct dma_fence *dma_fence)
+{
+	struct xe_hw_fence *fence = to_xe_hw_fence(dma_fence);
+
+	trace_xe_hw_fence_free(fence);
+	XE_BUG_ON(!list_empty(&fence->irq_link));
+	call_rcu(&dma_fence->rcu, fence_free);
+}
+
+static const struct dma_fence_ops xe_hw_fence_ops = {
+	.get_driver_name = xe_hw_fence_get_driver_name,
+	.get_timeline_name = xe_hw_fence_get_timeline_name,
+	.enable_signaling = xe_hw_fence_enable_signaling,
+	.signaled = xe_hw_fence_signaled,
+	.release = xe_hw_fence_release,
+};
+
+static struct xe_hw_fence *to_xe_hw_fence(struct dma_fence *fence)
+{
+	if (XE_WARN_ON(fence->ops != &xe_hw_fence_ops))
+		return NULL;
+
+	return container_of(fence, struct xe_hw_fence, dma);
+}
+
+struct xe_hw_fence *xe_hw_fence_create(struct xe_hw_fence_ctx *ctx,
+				       struct iosys_map seqno_map)
+{
+	struct xe_hw_fence *fence;
+
+	fence = fence_alloc();
+	if (!fence)
+		return ERR_PTR(-ENOMEM);
+
+	dma_fence_init(&fence->dma, &xe_hw_fence_ops, &ctx->irq->lock,
+		       ctx->dma_fence_ctx, ctx->next_seqno++);
+
+	fence->ctx = ctx;
+	fence->seqno_map = seqno_map;
+	INIT_LIST_HEAD(&fence->irq_link);
+
+	trace_xe_hw_fence_create(fence);
+
+	return fence;
+}