1 files changed, 445 insertions, 0 deletions
diff --git a/drivers/misc/habanalabs/command_buffer.c b/drivers/misc/habanalabs/command_buffer.c
new file mode 100644
index 000000000000..85f75806a9a7
--- /dev/null
+++ b/drivers/misc/habanalabs/command_buffer.c
@@ -0,0 +1,445 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Copyright 2016-2019 HabanaLabs, Ltd.
+ * All Rights Reserved.
+ */
+
+#include <uapi/misc/habanalabs.h>
+#include "habanalabs.h"
+
+#include <linux/mm.h>
+#include <linux/slab.h>
+
+static void cb_fini(struct hl_device *hdev, struct hl_cb *cb)
+{
+	hdev->asic_funcs->dma_free_coherent(hdev, cb->size,
+			(void *) (uintptr_t) cb->kernel_address,
+			cb->bus_address);
+	kfree(cb);
+}
+
+static void cb_do_release(struct hl_device *hdev, struct hl_cb *cb)
+{
+	if (cb->is_pool) {
+		spin_lock(&hdev->cb_pool_lock);
+		list_add(&cb->pool_list, &hdev->cb_pool);
+		spin_unlock(&hdev->cb_pool_lock);
+	} else {
+		cb_fini(hdev, cb);
+	}
+}
+
+static void cb_release(struct kref *ref)
+{
+	struct hl_device *hdev;
+	struct hl_cb *cb;
+
+	cb = container_of(ref, struct hl_cb, refcount);
+	hdev = cb->hdev;
+
+	hl_debugfs_remove_cb(cb);
+
+	cb_do_release(hdev, cb);
+}
+
+static struct hl_cb *hl_cb_alloc(struct hl_device *hdev, u32 cb_size,
+					int ctx_id)
+{
+	struct hl_cb *cb;
+	void *p;
+
+	/*
+	 * We use of GFP_ATOMIC here because this function can be called from
+	 * the latency-sensitive code path for command submission. Due to H/W
+	 * limitations in some of the ASICs, the kernel must copy the user CB
+	 * that is designated for an external queue and actually enqueue
+	 * the kernel's copy. Hence, we must never sleep in this code section
+	 * and must use GFP_ATOMIC for all memory allocations.
+	 */
+	if (ctx_id == HL_KERNEL_ASID_ID)
+		cb = kzalloc(sizeof(*cb), GFP_ATOMIC);
+	else
+		cb = kzalloc(sizeof(*cb), GFP_KERNEL);
+
+	if (!cb)
+		return NULL;
+
+	if (ctx_id == HL_KERNEL_ASID_ID)
+		p = hdev->asic_funcs->dma_alloc_coherent(hdev, cb_size,
+						&cb->bus_address, GFP_ATOMIC);
+	else
+		p = hdev->asic_funcs->dma_alloc_coherent(hdev, cb_size,
+						&cb->bus_address,
+						GFP_USER | __GFP_ZERO);
+	if (!p) {
+		dev_err(hdev->dev,
+			"failed to allocate %d of dma memory for CB\n",
+			cb_size);
+		kfree(cb);
+		return NULL;
+	}
+
+	cb->kernel_address = (u64) (uintptr_t) p;
+	cb->size = cb_size;
+
+	return cb;
+}
+
+int hl_cb_create(struct hl_device *hdev, struct hl_cb_mgr *mgr,
+			u32 cb_size, u64 *handle, int ctx_id)
+{
+	struct hl_cb *cb;
+	bool alloc_new_cb = true;
+	int rc;
+
+	/*
+	 * Can't use generic function to check this because of special case
+	 * where we create a CB as part of the reset process
+	 */
+	if ((hdev->disabled) || ((atomic_read(&hdev->in_reset)) &&
+					(ctx_id != HL_KERNEL_ASID_ID))) {
+		dev_warn_ratelimited(hdev->dev,
+			"Device is disabled or in reset. Can't create new CBs\n");
+		rc = -EBUSY;
+		goto out_err;
+	}
+
+	if (cb_size > HL_MAX_CB_SIZE) {
+		dev_err(hdev->dev,
+			"CB size %d must be less then %d\n",
+			cb_size, HL_MAX_CB_SIZE);
+		rc = -EINVAL;
+		goto out_err;
+	}
+
+	/* Minimum allocation must be PAGE SIZE */
+	if (cb_size < PAGE_SIZE)
+		cb_size = PAGE_SIZE;
+
+	if (ctx_id == HL_KERNEL_ASID_ID &&
+			cb_size <= hdev->asic_prop.cb_pool_cb_size) {
+
+		spin_lock(&hdev->cb_pool_lock);
+		if (!list_empty(&hdev->cb_pool)) {
+			cb = list_first_entry(&hdev->cb_pool, typeof(*cb),
+					pool_list);
+			list_del(&cb->pool_list);
+			spin_unlock(&hdev->cb_pool_lock);
+			alloc_new_cb = false;
+		} else {
+			spin_unlock(&hdev->cb_pool_lock);
+			dev_dbg(hdev->dev, "CB pool is empty\n");
+		}
+	}
+
+	if (alloc_new_cb) {
+		cb = hl_cb_alloc(hdev, cb_size, ctx_id);
+		if (!cb) {
+			rc = -ENOMEM;
+			goto out_err;
+		}
+	}
+
+	cb->hdev = hdev;
+	cb->ctx_id = ctx_id;
+
+	spin_lock(&mgr->cb_lock);
+	rc = idr_alloc(&mgr->cb_handles, cb, 1, 0, GFP_ATOMIC);
+	spin_unlock(&mgr->cb_lock);
+
+	if (rc < 0) {
+		dev_err(hdev->dev, "Failed to allocate IDR for a new CB\n");
+		goto release_cb;
+	}
+
+	cb->id = rc;
+
+	kref_init(&cb->refcount);
+	spin_lock_init(&cb->lock);
+
+	/*
+	 * idr is 32-bit so we can safely OR it with a mask that is above
+	 * 32 bit
+	 */
+	*handle = cb->id | HL_MMAP_CB_MASK;
+	*handle <<= PAGE_SHIFT;
+
+	hl_debugfs_add_cb(cb);
+
+	return 0;
+
+release_cb:
+	cb_do_release(hdev, cb);
+out_err:
+	*handle = 0;
+
+	return rc;
+}
+
+int hl_cb_destroy(struct hl_device *hdev, struct hl_cb_mgr *mgr, u64 cb_handle)
+{
+	struct hl_cb *cb;
+	u32 handle;
+	int rc = 0;
+
+	/*
+	 * handle was given to user to do mmap, I need to shift it back to
+	 * how the idr module gave it to me
+	 */
+	cb_handle >>= PAGE_SHIFT;
+	handle = (u32) cb_handle;
+
+	spin_lock(&mgr->cb_lock);
+
+	cb = idr_find(&mgr->cb_handles, handle);
+	if (cb) {
+		idr_remove(&mgr->cb_handles, handle);
+		spin_unlock(&mgr->cb_lock);
+		kref_put(&cb->refcount, cb_release);
+	} else {
+		spin_unlock(&mgr->cb_lock);
+		dev_err(hdev->dev,
+			"CB destroy failed, no match to handle 0x%x\n", handle);
+		rc = -EINVAL;
+	}
+
+	return rc;
+}
+
+int hl_cb_ioctl(struct hl_fpriv *hpriv, void *data)
+{
+	union hl_cb_args *args = data;
+	struct hl_device *hdev = hpriv->hdev;
+	u64 handle;
+	int rc;
+
+	switch (args->in.op) {
+	case HL_CB_OP_CREATE:
+		rc = hl_cb_create(hdev, &hpriv->cb_mgr, args->in.cb_size,
+					&handle, hpriv->ctx->asid);
+		memset(args, 0, sizeof(*args));
+		args->out.cb_handle = handle;
+		break;
+	case HL_CB_OP_DESTROY:
+		rc = hl_cb_destroy(hdev, &hpriv->cb_mgr,
+					args->in.cb_handle);
+		break;
+	default:
+		rc = -ENOTTY;
+		break;
+	}
+
+	return rc;
+}
+
+static void cb_vm_close(struct vm_area_struct *vma)
+{
+	struct hl_cb *cb = (struct hl_cb *) vma->vm_private_data;
+	long new_mmap_size;
+
+	new_mmap_size = cb->mmap_size - (vma->vm_end - vma->vm_start);
+
+	if (new_mmap_size > 0) {
+		cb->mmap_size = new_mmap_size;
+		return;
+	}
+
+	spin_lock(&cb->lock);
+	cb->mmap = false;
+	spin_unlock(&cb->lock);
+
+	hl_cb_put(cb);
+	vma->vm_private_data = NULL;
+}
+
+static const struct vm_operations_struct cb_vm_ops = {
+	.close = cb_vm_close
+};
+
+int hl_cb_mmap(struct hl_fpriv *hpriv, struct vm_area_struct *vma)
+{
+	struct hl_device *hdev = hpriv->hdev;
+	struct hl_cb *cb;
+	phys_addr_t address;
+	u32 handle;
+	int rc;
+
+	handle = vma->vm_pgoff;
+
+	/* reference was taken here */
+	cb = hl_cb_get(hdev, &hpriv->cb_mgr, handle);
+	if (!cb) {
+		dev_err(hdev->dev,
+			"CB mmap failed, no match to handle %d\n", handle);
+		return -EINVAL;
+	}
+
+	/* Validation check */
+	if ((vma->vm_end - vma->vm_start) != ALIGN(cb->size, PAGE_SIZE)) {
+		dev_err(hdev->dev,
+			"CB mmap failed, mmap size 0x%lx != 0x%x cb size\n",
+			vma->vm_end - vma->vm_start, cb->size);
+		rc = -EINVAL;
+		goto put_cb;
+	}
+
+	spin_lock(&cb->lock);
+
+	if (cb->mmap) {
+		dev_err(hdev->dev,
+			"CB mmap failed, CB already mmaped to user\n");
+		rc = -EINVAL;
+		goto release_lock;
+	}
+
+	cb->mmap = true;
+
+	spin_unlock(&cb->lock);
+
+	vma->vm_ops = &cb_vm_ops;
+
+	/*
+	 * Note: We're transferring the cb reference to
+	 * vma->vm_private_data here.
+	 */
+
+	vma->vm_private_data = cb;
+
+	/* Calculate address for CB */
+	address = virt_to_phys((void *) (uintptr_t) cb->kernel_address);
+
+	rc = hdev->asic_funcs->cb_mmap(hdev, vma, cb->kernel_address,
+					address, cb->size);
+
+	if (rc) {
+		spin_lock(&cb->lock);
+		cb->mmap = false;
+		goto release_lock;
+	}
+
+	cb->mmap_size = cb->size;
+
+	return 0;
+
+release_lock:
+	spin_unlock(&cb->lock);
+put_cb:
+	hl_cb_put(cb);
+	return rc;
+}
+
+struct hl_cb *hl_cb_get(struct hl_device *hdev, struct hl_cb_mgr *mgr,
+			u32 handle)
+{
+	struct hl_cb *cb;
+
+	spin_lock(&mgr->cb_lock);
+	cb = idr_find(&mgr->cb_handles, handle);
+
+	if (!cb) {
+		spin_unlock(&mgr->cb_lock);
+		dev_warn(hdev->dev,
+			"CB get failed, no match to handle %d\n", handle);
+		return NULL;
+	}
+
+	kref_get(&cb->refcount);
+
+	spin_unlock(&mgr->cb_lock);
+
+	return cb;
+
+}
+
+void hl_cb_put(struct hl_cb *cb)
+{
+	kref_put(&cb->refcount, cb_release);
+}
+
+void hl_cb_mgr_init(struct hl_cb_mgr *mgr)
+{
+	spin_lock_init(&mgr->cb_lock);
+	idr_init(&mgr->cb_handles);
+}
+
+void hl_cb_mgr_fini(struct hl_device *hdev, struct hl_cb_mgr *mgr)
+{
+	struct hl_cb *cb;
+	struct idr *idp;
+	u32 id;
+
+	idp = &mgr->cb_handles;
+
+	idr_for_each_entry(idp, cb, id) {
+		if (kref_put(&cb->refcount, cb_release) != 1)
+			dev_err(hdev->dev,
+				"CB %d for CTX ID %d is still alive\n",
+				id, cb->ctx_id);
+	}
+
+	idr_destroy(&mgr->cb_handles);
+}
+
+struct hl_cb *hl_cb_kernel_create(struct hl_device *hdev, u32 cb_size)
+{
+	u64 cb_handle;
+	struct hl_cb *cb;
+	int rc;
+
+	rc = hl_cb_create(hdev, &hdev->kernel_cb_mgr, cb_size, &cb_handle,
+			HL_KERNEL_ASID_ID);
+	if (rc) {
+		dev_err(hdev->dev, "Failed to allocate CB for KMD %d\n", rc);
+		return NULL;
+	}
+
+	cb_handle >>= PAGE_SHIFT;
+	cb = hl_cb_get(hdev, &hdev->kernel_cb_mgr, (u32) cb_handle);
+	/* hl_cb_get should never fail here so use kernel WARN */
+	WARN(!cb, "Kernel CB handle invalid 0x%x\n", (u32) cb_handle);
+	if (!cb)
+		goto destroy_cb;
+
+	return cb;
+
+destroy_cb:
+	hl_cb_destroy(hdev, &hdev->kernel_cb_mgr, cb_handle << PAGE_SHIFT);
+
+	return NULL;
+}
+
+int hl_cb_pool_init(struct hl_device *hdev)
+{
+	struct hl_cb *cb;
+	int i;
+
+	INIT_LIST_HEAD(&hdev->cb_pool);
+	spin_lock_init(&hdev->cb_pool_lock);
+
+	for (i = 0 ; i < hdev->asic_prop.cb_pool_cb_cnt ; i++) {
+		cb = hl_cb_alloc(hdev, hdev->asic_prop.cb_pool_cb_size,
+				HL_KERNEL_ASID_ID);
+		if (cb) {
+			cb->is_pool = true;
+			list_add(&cb->pool_list, &hdev->cb_pool);
+		} else {
+			hl_cb_pool_fini(hdev);
+			return -ENOMEM;
+		}
+	}
+
+	return 0;
+}
+
+int hl_cb_pool_fini(struct hl_device *hdev)
+{
+	struct hl_cb *cb, *tmp;
+
+	list_for_each_entry_safe(cb, tmp, &hdev->cb_pool, pool_list) {
+		list_del(&cb->pool_list);
+		cb_fini(hdev, cb);
+	}
+
+	return 0;
+}