1 files changed, 215 insertions, 0 deletions
diff --git a/drivers/misc/habanalabs/context.c b/drivers/misc/habanalabs/context.c
new file mode 100644
index 000000000000..619ace1c4ef7
--- /dev/null
+++ b/drivers/misc/habanalabs/context.c
@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Copyright 2016-2019 HabanaLabs, Ltd.
+ * All Rights Reserved.
+ */
+
+#include "habanalabs.h"
+
+#include <linux/slab.h>
+
+static void hl_ctx_fini(struct hl_ctx *ctx)
+{
+	struct hl_device *hdev = ctx->hdev;
+	int i;
+
+	/*
+	 * If we arrived here, there are no jobs waiting for this context
+	 * on its queues so we can safely remove it.
+	 * This is because for each CS, we increment the ref count and for
+	 * every CS that was finished we decrement it and we won't arrive
+	 * to this function unless the ref count is 0
+	 */
+
+	for (i = 0 ; i < HL_MAX_PENDING_CS ; i++)
+		dma_fence_put(ctx->cs_pending[i]);
+
+	if (ctx->asid != HL_KERNEL_ASID_ID) {
+		hl_vm_ctx_fini(ctx);
+		hl_asid_free(hdev, ctx->asid);
+	}
+}
+
+void hl_ctx_do_release(struct kref *ref)
+{
+	struct hl_ctx *ctx;
+
+	ctx = container_of(ref, struct hl_ctx, refcount);
+
+	hl_ctx_fini(ctx);
+
+	if (ctx->hpriv)
+		hl_hpriv_put(ctx->hpriv);
+
+	kfree(ctx);
+}
+
+int hl_ctx_create(struct hl_device *hdev, struct hl_fpriv *hpriv)
+{
+	struct hl_ctx_mgr *mgr = &hpriv->ctx_mgr;
+	struct hl_ctx *ctx;
+	int rc;
+
+	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+	if (!ctx) {
+		rc = -ENOMEM;
+		goto out_err;
+	}
+
+	rc = hl_ctx_init(hdev, ctx, false);
+	if (rc)
+		goto free_ctx;
+
+	hl_hpriv_get(hpriv);
+	ctx->hpriv = hpriv;
+
+	/* TODO: remove for multiple contexts */
+	hpriv->ctx = ctx;
+	hdev->user_ctx = ctx;
+
+	mutex_lock(&mgr->ctx_lock);
+	rc = idr_alloc(&mgr->ctx_handles, ctx, 1, 0, GFP_KERNEL);
+	mutex_unlock(&mgr->ctx_lock);
+
+	if (rc < 0) {
+		dev_err(hdev->dev, "Failed to allocate IDR for a new CTX\n");
+		hl_ctx_free(hdev, ctx);
+		goto out_err;
+	}
+
+	return 0;
+
+free_ctx:
+	kfree(ctx);
+out_err:
+	return rc;
+}
+
+void hl_ctx_free(struct hl_device *hdev, struct hl_ctx *ctx)
+{
+	if (kref_put(&ctx->refcount, hl_ctx_do_release) == 1)
+		return;
+
+	dev_warn(hdev->dev,
+		"Context %d closed or terminated but its CS are executing\n",
+		ctx->asid);
+}
+
+int hl_ctx_init(struct hl_device *hdev, struct hl_ctx *ctx, bool is_kernel_ctx)
+{
+	int rc = 0;
+
+	ctx->hdev = hdev;
+
+	kref_init(&ctx->refcount);
+
+	ctx->cs_sequence = 1;
+	spin_lock_init(&ctx->cs_lock);
+	atomic_set(&ctx->thread_restore_token, 1);
+	ctx->thread_restore_wait_token = 0;
+
+	if (is_kernel_ctx) {
+		ctx->asid = HL_KERNEL_ASID_ID; /* KMD gets ASID 0 */
+	} else {
+		ctx->asid = hl_asid_alloc(hdev);
+		if (!ctx->asid) {
+			dev_err(hdev->dev, "No free ASID, failed to create context\n");
+			return -ENOMEM;
+		}
+
+		rc = hl_vm_ctx_init(ctx);
+		if (rc) {
+			dev_err(hdev->dev, "Failed to init mem ctx module\n");
+			rc = -ENOMEM;
+			goto mem_ctx_err;
+		}
+	}
+
+	return 0;
+
+mem_ctx_err:
+	if (ctx->asid != HL_KERNEL_ASID_ID)
+		hl_asid_free(hdev, ctx->asid);
+
+	return rc;
+}
+
+void hl_ctx_get(struct hl_device *hdev, struct hl_ctx *ctx)
+{
+	kref_get(&ctx->refcount);
+}
+
+int hl_ctx_put(struct hl_ctx *ctx)
+{
+	return kref_put(&ctx->refcount, hl_ctx_do_release);
+}
+
+struct dma_fence *hl_ctx_get_fence(struct hl_ctx *ctx, u64 seq)
+{
+	struct hl_device *hdev = ctx->hdev;
+	struct dma_fence *fence;
+
+	spin_lock(&ctx->cs_lock);
+
+	if (seq >= ctx->cs_sequence) {
+		dev_notice(hdev->dev,
+			"Can't wait on seq %llu because current CS is at seq %llu\n",
+			seq, ctx->cs_sequence);
+		spin_unlock(&ctx->cs_lock);
+		return ERR_PTR(-EINVAL);
+	}
+
+
+	if (seq + HL_MAX_PENDING_CS < ctx->cs_sequence) {
+		dev_dbg(hdev->dev,
+			"Can't wait on seq %llu because current CS is at seq %llu (Fence is gone)\n",
+			seq, ctx->cs_sequence);
+		spin_unlock(&ctx->cs_lock);
+		return NULL;
+	}
+
+	fence = dma_fence_get(
+			ctx->cs_pending[seq & (HL_MAX_PENDING_CS - 1)]);
+	spin_unlock(&ctx->cs_lock);
+
+	return fence;
+}
+
+/*
+ * hl_ctx_mgr_init - initialize the context manager
+ *
+ * @mgr: pointer to context manager structure
+ *
+ * This manager is an object inside the hpriv object of the user process.
+ * The function is called when a user process opens the FD.
+ */
+void hl_ctx_mgr_init(struct hl_ctx_mgr *mgr)
+{
+	mutex_init(&mgr->ctx_lock);
+	idr_init(&mgr->ctx_handles);
+}
+
+/*
+ * hl_ctx_mgr_fini - finalize the context manager
+ *
+ * @hdev: pointer to device structure
+ * @mgr: pointer to context manager structure
+ *
+ * This function goes over all the contexts in the manager and frees them.
+ * It is called when a process closes the FD.
+ */
+void hl_ctx_mgr_fini(struct hl_device *hdev, struct hl_ctx_mgr *mgr)
+{
+	struct hl_ctx *ctx;
+	struct idr *idp;
+	u32 id;
+
+	idp = &mgr->ctx_handles;
+
+	idr_for_each_entry(idp, ctx, id)
+		hl_ctx_free(hdev, ctx);
+
+	idr_destroy(&mgr->ctx_handles);
+	mutex_destroy(&mgr->ctx_lock);
+}