1 files changed, 595 insertions, 0 deletions
diff --git a/drivers/misc/uacce/uacce.c b/drivers/misc/uacce/uacce.c
new file mode 100644
index 000000000..b70a01313
--- /dev/null
+++ b/drivers/misc/uacce/uacce.c
@@ -0,0 +1,595 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include <linux/compat.h>
+#include <linux/dma-mapping.h>
+#include <linux/iommu.h>
+#include <linux/module.h>
+#include <linux/poll.h>
+#include <linux/slab.h>
+#include <linux/uacce.h>
+
+static struct class *uacce_class;
+static dev_t uacce_devt;
+static DEFINE_XARRAY_ALLOC(uacce_xa);
+
+/*
+ * If the parent driver or the device disappears, the queue state is invalid and
+ * ops are not usable anymore.
+ */
+static bool uacce_queue_is_valid(struct uacce_queue *q)
+{
+	return q->state == UACCE_Q_INIT || q->state == UACCE_Q_STARTED;
+}
+
+static int uacce_start_queue(struct uacce_queue *q)
+{
+	int ret;
+
+	if (q->state != UACCE_Q_INIT)
+		return -EINVAL;
+
+	if (q->uacce->ops->start_queue) {
+		ret = q->uacce->ops->start_queue(q);
+		if (ret < 0)
+			return ret;
+	}
+
+	q->state = UACCE_Q_STARTED;
+	return 0;
+}
+
+static int uacce_put_queue(struct uacce_queue *q)
+{
+	struct uacce_device *uacce = q->uacce;
+
+	if ((q->state == UACCE_Q_STARTED) && uacce->ops->stop_queue)
+		uacce->ops->stop_queue(q);
+
+	if ((q->state == UACCE_Q_INIT || q->state == UACCE_Q_STARTED) &&
+	     uacce->ops->put_queue)
+		uacce->ops->put_queue(q);
+
+	q->state = UACCE_Q_ZOMBIE;
+
+	return 0;
+}
+
+static long uacce_fops_unl_ioctl(struct file *filep,
+				 unsigned int cmd, unsigned long arg)
+{
+	struct uacce_queue *q = filep->private_data;
+	struct uacce_device *uacce = q->uacce;
+	long ret = -ENXIO;
+
+	/*
+	 * uacce->ops->ioctl() may take the mmap_lock when copying arg to/from
+	 * user. Avoid a circular lock dependency with uacce_fops_mmap(), which
+	 * gets called with mmap_lock held, by taking uacce->mutex instead of
+	 * q->mutex. Doing this in uacce_fops_mmap() is not possible because
+	 * uacce_fops_open() calls iommu_sva_bind_device(), which takes
+	 * mmap_lock, while holding uacce->mutex.
+	 */
+	mutex_lock(&uacce->mutex);
+	if (!uacce_queue_is_valid(q))
+		goto out_unlock;
+
+	switch (cmd) {
+	case UACCE_CMD_START_Q:
+		ret = uacce_start_queue(q);
+		break;
+	case UACCE_CMD_PUT_Q:
+		ret = uacce_put_queue(q);
+		break;
+	default:
+		if (uacce->ops->ioctl)
+			ret = uacce->ops->ioctl(q, cmd, arg);
+		else
+			ret = -EINVAL;
+	}
+out_unlock:
+	mutex_unlock(&uacce->mutex);
+	return ret;
+}
+
+#ifdef CONFIG_COMPAT
+static long uacce_fops_compat_ioctl(struct file *filep,
+				   unsigned int cmd, unsigned long arg)
+{
+	arg = (unsigned long)compat_ptr(arg);
+
+	return uacce_fops_unl_ioctl(filep, cmd, arg);
+}
+#endif
+
+static int uacce_bind_queue(struct uacce_device *uacce, struct uacce_queue *q)
+{
+	u32 pasid;
+	struct iommu_sva *handle;
+
+	if (!(uacce->flags & UACCE_DEV_SVA))
+		return 0;
+
+	handle = iommu_sva_bind_device(uacce->parent, current->mm, NULL);
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
+
+	pasid = iommu_sva_get_pasid(handle);
+	if (pasid == IOMMU_PASID_INVALID) {
+		iommu_sva_unbind_device(handle);
+		return -ENODEV;
+	}
+
+	q->handle = handle;
+	q->pasid = pasid;
+	return 0;
+}
+
+static void uacce_unbind_queue(struct uacce_queue *q)
+{
+	if (!q->handle)
+		return;
+	iommu_sva_unbind_device(q->handle);
+	q->handle = NULL;
+}
+
+static int uacce_fops_open(struct inode *inode, struct file *filep)
+{
+	struct uacce_device *uacce;
+	struct uacce_queue *q;
+	int ret;
+
+	uacce = xa_load(&uacce_xa, iminor(inode));
+	if (!uacce)
+		return -ENODEV;
+
+	q = kzalloc(sizeof(struct uacce_queue), GFP_KERNEL);
+	if (!q)
+		return -ENOMEM;
+
+	mutex_lock(&uacce->mutex);
+
+	if (!uacce->parent) {
+		ret = -EINVAL;
+		goto out_with_mem;
+	}
+
+	ret = uacce_bind_queue(uacce, q);
+	if (ret)
+		goto out_with_mem;
+
+	q->uacce = uacce;
+
+	if (uacce->ops->get_queue) {
+		ret = uacce->ops->get_queue(uacce, q->pasid, q);
+		if (ret < 0)
+			goto out_with_bond;
+	}
+
+	init_waitqueue_head(&q->wait);
+	filep->private_data = q;
+	uacce->inode = inode;
+	q->state = UACCE_Q_INIT;
+	mutex_init(&q->mutex);
+	list_add(&q->list, &uacce->queues);
+	mutex_unlock(&uacce->mutex);
+
+	return 0;
+
+out_with_bond:
+	uacce_unbind_queue(q);
+out_with_mem:
+	kfree(q);
+	mutex_unlock(&uacce->mutex);
+	return ret;
+}
+
+static int uacce_fops_release(struct inode *inode, struct file *filep)
+{
+	struct uacce_queue *q = filep->private_data;
+	struct uacce_device *uacce = q->uacce;
+
+	mutex_lock(&uacce->mutex);
+	uacce_put_queue(q);
+	uacce_unbind_queue(q);
+	list_del(&q->list);
+	mutex_unlock(&uacce->mutex);
+	kfree(q);
+
+	return 0;
+}
+
+static void uacce_vma_close(struct vm_area_struct *vma)
+{
+	struct uacce_queue *q = vma->vm_private_data;
+	struct uacce_qfile_region *qfr = NULL;
+
+	if (vma->vm_pgoff < UACCE_MAX_REGION)
+		qfr = q->qfrs[vma->vm_pgoff];
+
+	kfree(qfr);
+}
+
+static const struct vm_operations_struct uacce_vm_ops = {
+	.close = uacce_vma_close,
+};
+
+static int uacce_fops_mmap(struct file *filep, struct vm_area_struct *vma)
+{
+	struct uacce_queue *q = filep->private_data;
+	struct uacce_device *uacce = q->uacce;
+	struct uacce_qfile_region *qfr;
+	enum uacce_qfrt type = UACCE_MAX_REGION;
+	int ret = 0;
+
+	if (vma->vm_pgoff < UACCE_MAX_REGION)
+		type = vma->vm_pgoff;
+	else
+		return -EINVAL;
+
+	qfr = kzalloc(sizeof(*qfr), GFP_KERNEL);
+	if (!qfr)
+		return -ENOMEM;
+
+	vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_WIPEONFORK;
+	vma->vm_ops = &uacce_vm_ops;
+	vma->vm_private_data = q;
+	qfr->type = type;
+
+	mutex_lock(&q->mutex);
+	if (!uacce_queue_is_valid(q)) {
+		ret = -ENXIO;
+		goto out_with_lock;
+	}
+
+	if (q->qfrs[type]) {
+		ret = -EEXIST;
+		goto out_with_lock;
+	}
+
+	switch (type) {
+	case UACCE_QFRT_MMIO:
+	case UACCE_QFRT_DUS:
+		if (!uacce->ops->mmap) {
+			ret = -EINVAL;
+			goto out_with_lock;
+		}
+
+		ret = uacce->ops->mmap(q, vma, qfr);
+		if (ret)
+			goto out_with_lock;
+		break;
+
+	default:
+		ret = -EINVAL;
+		goto out_with_lock;
+	}
+
+	q->qfrs[type] = qfr;
+	mutex_unlock(&q->mutex);
+
+	return ret;
+
+out_with_lock:
+	mutex_unlock(&q->mutex);
+	kfree(qfr);
+	return ret;
+}
+
+static __poll_t uacce_fops_poll(struct file *file, poll_table *wait)
+{
+	struct uacce_queue *q = file->private_data;
+	struct uacce_device *uacce = q->uacce;
+	__poll_t ret = 0;
+
+	mutex_lock(&q->mutex);
+	if (!uacce_queue_is_valid(q))
+		goto out_unlock;
+
+	poll_wait(file, &q->wait, wait);
+
+	if (uacce->ops->is_q_updated && uacce->ops->is_q_updated(q))
+		ret = EPOLLIN | EPOLLRDNORM;
+
+out_unlock:
+	mutex_unlock(&q->mutex);
+	return ret;
+}
+
+static const struct file_operations uacce_fops = {
+	.owner		= THIS_MODULE,
+	.open		= uacce_fops_open,
+	.release	= uacce_fops_release,
+	.unlocked_ioctl	= uacce_fops_unl_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= uacce_fops_compat_ioctl,
+#endif
+	.mmap		= uacce_fops_mmap,
+	.poll		= uacce_fops_poll,
+};
+
+#define to_uacce_device(dev) container_of(dev, struct uacce_device, dev)
+
+static ssize_t api_show(struct device *dev,
+			struct device_attribute *attr, char *buf)
+{
+	struct uacce_device *uacce = to_uacce_device(dev);
+
+	return sysfs_emit(buf, "%s\n", uacce->api_ver);
+}
+
+static ssize_t flags_show(struct device *dev,
+			  struct device_attribute *attr, char *buf)
+{
+	struct uacce_device *uacce = to_uacce_device(dev);
+
+	return sysfs_emit(buf, "%u\n", uacce->flags);
+}
+
+static ssize_t available_instances_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct uacce_device *uacce = to_uacce_device(dev);
+
+	if (!uacce->ops->get_available_instances)
+		return -ENODEV;
+
+	return sysfs_emit(buf, "%d\n",
+		       uacce->ops->get_available_instances(uacce));
+}
+
+static ssize_t algorithms_show(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	struct uacce_device *uacce = to_uacce_device(dev);
+
+	return sysfs_emit(buf, "%s\n", uacce->algs);
+}
+
+static ssize_t region_mmio_size_show(struct device *dev,
+				     struct device_attribute *attr, char *buf)
+{
+	struct uacce_device *uacce = to_uacce_device(dev);
+
+	return sysfs_emit(buf, "%lu\n",
+		       uacce->qf_pg_num[UACCE_QFRT_MMIO] << PAGE_SHIFT);
+}
+
+static ssize_t region_dus_size_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct uacce_device *uacce = to_uacce_device(dev);
+
+	return sysfs_emit(buf, "%lu\n",
+		       uacce->qf_pg_num[UACCE_QFRT_DUS] << PAGE_SHIFT);
+}
+
+static DEVICE_ATTR_RO(api);
+static DEVICE_ATTR_RO(flags);
+static DEVICE_ATTR_RO(available_instances);
+static DEVICE_ATTR_RO(algorithms);
+static DEVICE_ATTR_RO(region_mmio_size);
+static DEVICE_ATTR_RO(region_dus_size);
+
+static struct attribute *uacce_dev_attrs[] = {
+	&dev_attr_api.attr,
+	&dev_attr_flags.attr,
+	&dev_attr_available_instances.attr,
+	&dev_attr_algorithms.attr,
+	&dev_attr_region_mmio_size.attr,
+	&dev_attr_region_dus_size.attr,
+	NULL,
+};
+
+static umode_t uacce_dev_is_visible(struct kobject *kobj,
+				    struct attribute *attr, int n)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct uacce_device *uacce = to_uacce_device(dev);
+
+	if (((attr == &dev_attr_region_mmio_size.attr) &&
+	    (!uacce->qf_pg_num[UACCE_QFRT_MMIO])) ||
+	    ((attr == &dev_attr_region_dus_size.attr) &&
+	    (!uacce->qf_pg_num[UACCE_QFRT_DUS])))
+		return 0;
+
+	return attr->mode;
+}
+
+static struct attribute_group uacce_dev_group = {
+	.is_visible	= uacce_dev_is_visible,
+	.attrs		= uacce_dev_attrs,
+};
+
+__ATTRIBUTE_GROUPS(uacce_dev);
+
+static void uacce_release(struct device *dev)
+{
+	struct uacce_device *uacce = to_uacce_device(dev);
+
+	kfree(uacce);
+}
+
+static unsigned int uacce_enable_sva(struct device *parent, unsigned int flags)
+{
+	int ret;
+
+	if (!(flags & UACCE_DEV_SVA))
+		return flags;
+
+	flags &= ~UACCE_DEV_SVA;
+
+	ret = iommu_dev_enable_feature(parent, IOMMU_DEV_FEAT_IOPF);
+	if (ret) {
+		dev_err(parent, "failed to enable IOPF feature! ret = %pe\n", ERR_PTR(ret));
+		return flags;
+	}
+
+	ret = iommu_dev_enable_feature(parent, IOMMU_DEV_FEAT_SVA);
+	if (ret) {
+		dev_err(parent, "failed to enable SVA feature! ret = %pe\n", ERR_PTR(ret));
+		iommu_dev_disable_feature(parent, IOMMU_DEV_FEAT_IOPF);
+		return flags;
+	}
+
+	return flags | UACCE_DEV_SVA;
+}
+
+static void uacce_disable_sva(struct uacce_device *uacce)
+{
+	if (!(uacce->flags & UACCE_DEV_SVA))
+		return;
+
+	iommu_dev_disable_feature(uacce->parent, IOMMU_DEV_FEAT_SVA);
+	iommu_dev_disable_feature(uacce->parent, IOMMU_DEV_FEAT_IOPF);
+}
+
+/**
+ * uacce_alloc() - alloc an accelerator
+ * @parent: pointer of uacce parent device
+ * @interface: pointer of uacce_interface for register
+ *
+ * Returns uacce pointer if success and ERR_PTR if not
+ * Need check returned negotiated uacce->flags
+ */
+struct uacce_device *uacce_alloc(struct device *parent,
+				 struct uacce_interface *interface)
+{
+	unsigned int flags = interface->flags;
+	struct uacce_device *uacce;
+	int ret;
+
+	uacce = kzalloc(sizeof(struct uacce_device), GFP_KERNEL);
+	if (!uacce)
+		return ERR_PTR(-ENOMEM);
+
+	flags = uacce_enable_sva(parent, flags);
+
+	uacce->parent = parent;
+	uacce->flags = flags;
+	uacce->ops = interface->ops;
+
+	ret = xa_alloc(&uacce_xa, &uacce->dev_id, uacce, xa_limit_32b,
+		       GFP_KERNEL);
+	if (ret < 0)
+		goto err_with_uacce;
+
+	INIT_LIST_HEAD(&uacce->queues);
+	mutex_init(&uacce->mutex);
+	device_initialize(&uacce->dev);
+	uacce->dev.devt = MKDEV(MAJOR(uacce_devt), uacce->dev_id);
+	uacce->dev.class = uacce_class;
+	uacce->dev.groups = uacce_dev_groups;
+	uacce->dev.parent = uacce->parent;
+	uacce->dev.release = uacce_release;
+	dev_set_name(&uacce->dev, "%s-%d", interface->name, uacce->dev_id);
+
+	return uacce;
+
+err_with_uacce:
+	uacce_disable_sva(uacce);
+	kfree(uacce);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(uacce_alloc);
+
+/**
+ * uacce_register() - add the accelerator to cdev and export to user space
+ * @uacce: The initialized uacce device
+ *
+ * Return 0 if register succeeded, or an error.
+ */
+int uacce_register(struct uacce_device *uacce)
+{
+	if (!uacce)
+		return -ENODEV;
+
+	uacce->cdev = cdev_alloc();
+	if (!uacce->cdev)
+		return -ENOMEM;
+
+	uacce->cdev->ops = &uacce_fops;
+	uacce->cdev->owner = THIS_MODULE;
+
+	return cdev_device_add(uacce->cdev, &uacce->dev);
+}
+EXPORT_SYMBOL_GPL(uacce_register);
+
+/**
+ * uacce_remove() - remove the accelerator
+ * @uacce: the accelerator to remove
+ */
+void uacce_remove(struct uacce_device *uacce)
+{
+	struct uacce_queue *q, *next_q;
+
+	if (!uacce)
+		return;
+	/*
+	 * unmap remaining mapping from user space, preventing user still
+	 * access the mmaped area while parent device is already removed
+	 */
+	if (uacce->inode)
+		unmap_mapping_range(uacce->inode->i_mapping, 0, 0, 1);
+
+	/*
+	 * uacce_fops_open() may be running concurrently, even after we remove
+	 * the cdev. Holding uacce->mutex ensures that open() does not obtain a
+	 * removed uacce device.
+	 */
+	mutex_lock(&uacce->mutex);
+	/* ensure no open queue remains */
+	list_for_each_entry_safe(q, next_q, &uacce->queues, list) {
+		/*
+		 * Taking q->mutex ensures that fops do not use the defunct
+		 * uacce->ops after the queue is disabled.
+		 */
+		mutex_lock(&q->mutex);
+		uacce_put_queue(q);
+		mutex_unlock(&q->mutex);
+		uacce_unbind_queue(q);
+	}
+
+	/* disable sva now since no opened queues */
+	uacce_disable_sva(uacce);
+
+	if (uacce->cdev)
+		cdev_device_del(uacce->cdev, &uacce->dev);
+	xa_erase(&uacce_xa, uacce->dev_id);
+	/*
+	 * uacce exists as long as there are open fds, but ops will be freed
+	 * now. Ensure that bugs cause NULL deref rather than use-after-free.
+	 */
+	uacce->ops = NULL;
+	uacce->parent = NULL;
+	mutex_unlock(&uacce->mutex);
+	put_device(&uacce->dev);
+}
+EXPORT_SYMBOL_GPL(uacce_remove);
+
+static int __init uacce_init(void)
+{
+	int ret;
+
+	uacce_class = class_create(THIS_MODULE, UACCE_NAME);
+	if (IS_ERR(uacce_class))
+		return PTR_ERR(uacce_class);
+
+	ret = alloc_chrdev_region(&uacce_devt, 0, MINORMASK, UACCE_NAME);
+	if (ret)
+		class_destroy(uacce_class);
+
+	return ret;
+}
+
+static __exit void uacce_exit(void)
+{
+	unregister_chrdev_region(uacce_devt, MINORMASK);
+	class_destroy(uacce_class);
+}
+
+subsys_initcall(uacce_init);
+module_exit(uacce_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("HiSilicon Tech. Co., Ltd.");
+MODULE_DESCRIPTION("Accelerator interface for Userland applications");