1 files changed, 247 insertions, 0 deletions
diff --git a/drivers/misc/habanalabs/common/context.c b/drivers/misc/habanalabs/common/context.c
new file mode 100644
index 000000000000..3e375958e73b
--- /dev/null
+++ b/drivers/misc/habanalabs/common/context.c
@@ -0,0 +1,247 @@
+// 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 < hdev->asic_prop.max_pending_cs ; i++)
+		dma_fence_put(ctx->cs_pending[i]);
+
+	kfree(ctx->cs_pending);
+
+	if (ctx->asid != HL_KERNEL_ASID_ID) {
+		/* The engines are stopped as there is no executing CS, but the
+		 * Coresight might be still working by accessing addresses
+		 * related to the stopped engines. Hence stop it explicitly.
+		 * Stop only if this is the compute context, as there can be
+		 * only one compute context
+		 */
+		if ((hdev->in_debug) && (hdev->compute_ctx == ctx))
+			hl_device_set_debug_mode(hdev, false);
+
+		hl_vm_ctx_fini(ctx);
+		hl_asid_free(hdev, ctx->asid);
+	} else {
+		hl_mmu_ctx_fini(ctx);
+	}
+}
+
+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;
+	}
+
+	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");
+		goto free_ctx;
+	}
+
+	ctx->handle = rc;
+
+	rc = hl_ctx_init(hdev, ctx, false);
+	if (rc)
+		goto remove_from_idr;
+
+	hl_hpriv_get(hpriv);
+	ctx->hpriv = hpriv;
+
+	/* TODO: remove for multiple contexts per process */
+	hpriv->ctx = ctx;
+
+	/* TODO: remove the following line for multiple process support */
+	hdev->compute_ctx = ctx;
+
+	return 0;
+
+remove_from_idr:
+	mutex_lock(&mgr->ctx_lock);
+	idr_remove(&mgr->ctx_handles, ctx->handle);
+	mutex_unlock(&mgr->ctx_lock);
+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,
+		"user process released device but its command submissions are still executing\n");
+}
+
+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_ctx_switch_token, 1);
+	ctx->thread_ctx_switch_wait_token = 0;
+	ctx->cs_pending = kcalloc(hdev->asic_prop.max_pending_cs,
+				sizeof(struct dma_fence *),
+				GFP_KERNEL);
+	if (!ctx->cs_pending)
+		return -ENOMEM;
+
+	if (is_kernel_ctx) {
+		ctx->asid = HL_KERNEL_ASID_ID; /* Kernel driver gets ASID 0 */
+		rc = hl_mmu_ctx_init(ctx);
+		if (rc) {
+			dev_err(hdev->dev, "Failed to init mmu ctx module\n");
+			goto err_free_cs_pending;
+		}
+	} else {
+		ctx->asid = hl_asid_alloc(hdev);
+		if (!ctx->asid) {
+			dev_err(hdev->dev, "No free ASID, failed to create context\n");
+			rc = -ENOMEM;
+			goto err_free_cs_pending;
+		}
+
+		rc = hl_vm_ctx_init(ctx);
+		if (rc) {
+			dev_err(hdev->dev, "Failed to init mem ctx module\n");
+			rc = -ENOMEM;
+			goto err_asid_free;
+		}
+
+		rc = hdev->asic_funcs->ctx_init(ctx);
+		if (rc) {
+			dev_err(hdev->dev, "ctx_init failed\n");
+			goto err_vm_ctx_fini;
+		}
+	}
+
+	return 0;
+
+err_vm_ctx_fini:
+	hl_vm_ctx_fini(ctx);
+err_asid_free:
+	hl_asid_free(hdev, ctx->asid);
+err_free_cs_pending:
+	kfree(ctx->cs_pending);
+
+	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 asic_fixed_properties *asic_prop = &ctx->hdev->asic_prop;
+	struct dma_fence *fence;
+
+	spin_lock(&ctx->cs_lock);
+
+	if (seq >= ctx->cs_sequence) {
+		spin_unlock(&ctx->cs_lock);
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (seq + asic_prop->max_pending_cs < ctx->cs_sequence) {
+		spin_unlock(&ctx->cs_lock);
+		return NULL;
+	}
+
+	fence = dma_fence_get(
+			ctx->cs_pending[seq & (asic_prop->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);
+}