Message-Id: <1572331216-9503-3-git-send-email-zhangfei.gao@linaro.org>
Date:   Tue, 29 Oct 2019 14:40:15 +0800
From:   Zhangfei Gao <zhangfei.gao@...aro.org>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Arnd Bergmann <arnd@...db.de>,
        Herbert Xu <herbert@...dor.apana.org.au>,
        jonathan.cameron@...wei.com, grant.likely@....com,
        jean-philippe <jean-philippe@...aro.org>,
        Jerome Glisse <jglisse@...hat.com>,
        ilias.apalodimas@...aro.org, francois.ozog@...aro.org,
        kenneth-lee-2012@...mail.com, Wangzhou <wangzhou1@...ilicon.com>,
        "haojian . zhuang" <haojian.zhuang@...aro.org>,
        guodong.xu@...aro.org
Cc:     linux-accelerators@...ts.ozlabs.org, linux-kernel@...r.kernel.org,
        linux-crypto@...r.kernel.org, iommu@...ts.linux-foundation.org,
        Kenneth Lee <liguozhu@...ilicon.com>,
        Zaibo Xu <xuzaibo@...wei.com>,
        Zhangfei Gao <zhangfei.gao@...aro.org>
Subject: [PATCH v7 2/3] uacce: add uacce driver

From: Kenneth Lee <liguozhu@...ilicon.com>

Uacce (Unified/User-space-access-intended Accelerator Framework) targets to
provide Shared Virtual Addressing (SVA) between accelerators and processes.
So accelerator can access any data structure of the main cpu.
This differs from the data sharing between cpu and io device, which share
data content rather than address.
Since unified address, hardware and user space of process can share the
same virtual address in the communication.

Uacce create a chrdev for every registration, the queue is allocated to
the process when the chrdev is opened. Then the process can access the
hardware resource by interact with the queue file. By mmap the queue
file space to user space, the process can directly put requests to the
hardware without syscall to the kernel space.

Signed-off-by: Kenneth Lee <liguozhu@...ilicon.com>
Signed-off-by: Zaibo Xu <xuzaibo@...wei.com>
Signed-off-by: Zhou Wang <wangzhou1@...ilicon.com>
Signed-off-by: Zhangfei Gao <zhangfei.gao@...aro.org>
---
 Documentation/ABI/testing/sysfs-driver-uacce |  53 +++
 drivers/misc/Kconfig                         |   1 +
 drivers/misc/Makefile                        |   1 +
 drivers/misc/uacce/Kconfig                   |  13 +
 drivers/misc/uacce/Makefile                  |   2 +
 drivers/misc/uacce/uacce.c                   | 574 +++++++++++++++++++++++++++
 include/linux/uacce.h                        | 163 ++++++++
 include/uapi/misc/uacce/uacce.h              |  38 ++
 8 files changed, 845 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-driver-uacce
 create mode 100644 drivers/misc/uacce/Kconfig
 create mode 100644 drivers/misc/uacce/Makefile
 create mode 100644 drivers/misc/uacce/uacce.c
 create mode 100644 include/linux/uacce.h
 create mode 100644 include/uapi/misc/uacce/uacce.h

diff --git a/Documentation/ABI/testing/sysfs-driver-uacce b/Documentation/ABI/testing/sysfs-driver-uacce
new file mode 100644
index 0000000..35699dc
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-driver-uacce
@@ -0,0 +1,53 @@
+What:           /sys/class/uacce/<dev_name>/id
+Date:           Oct 2019
+KernelVersion:  5.5
+Contact:        linux-accelerators@...ts.ozlabs.org
+Description:    Id of the device.
+
+What:           /sys/class/uacce/<dev_name>/api
+Date:           Oct 2019
+KernelVersion:  5.5
+Contact:        linux-accelerators@...ts.ozlabs.org
+Description:    Api of the device, used by application to match the correct driver
+
+What:           /sys/class/uacce/<dev_name>/flags
+Date:           Oct 2019
+KernelVersion:  5.5
+Contact:        linux-accelerators@...ts.ozlabs.org
+Description:    Attributes of the device, see UACCE_DEV_xxx flag defined in uacce.h
+
+What:           /sys/class/uacce/<dev_name>/available_instances
+Date:           Oct 2019
+KernelVersion:  5.5
+Contact:        linux-accelerators@...ts.ozlabs.org
+Description:    Available instances left of the device
+
+What:           /sys/class/uacce/<dev_name>/algorithms
+Date:           Oct 2019
+KernelVersion:  5.5
+Contact:        linux-accelerators@...ts.ozlabs.org
+Description:    Algorithms supported by this accelerator
+
+What:           /sys/class/uacce/<dev_name>/qfrt_mmio_size
+Date:           Oct 2019
+KernelVersion:  5.5
+Contact:        linux-accelerators@...ts.ozlabs.org
+Description:    Page size of mmio region queue file
+
+What:           /sys/class/uacce/<dev_name>/qfrt_dus_size
+Date:           Oct 2019
+KernelVersion:  5.5
+Contact:        linux-accelerators@...ts.ozlabs.org
+Description:    Page size of dus region queue file
+
+What:           /sys/class/uacce/<dev_name>/numa_distance
+Date:           Oct 2019
+KernelVersion:  5.5
+Contact:        linux-accelerators@...ts.ozlabs.org
+Description:    Distance of device node to cpu node
+
+What:           /sys/class/uacce/<dev_name>/node_id
+Date:           Oct 2019
+KernelVersion:  5.5
+Contact:        linux-accelerators@...ts.ozlabs.org
+Description:    Id of the numa node
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index c55b637..929feb0 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -481,4 +481,5 @@ source "drivers/misc/cxl/Kconfig"
 source "drivers/misc/ocxl/Kconfig"
 source "drivers/misc/cardreader/Kconfig"
 source "drivers/misc/habanalabs/Kconfig"
+source "drivers/misc/uacce/Kconfig"
 endmenu
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index c1860d3..9abf292 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -56,4 +56,5 @@ obj-$(CONFIG_OCXL)		+= ocxl/
 obj-y				+= cardreader/
 obj-$(CONFIG_PVPANIC)   	+= pvpanic.o
 obj-$(CONFIG_HABANA_AI)		+= habanalabs/
+obj-$(CONFIG_UACCE)		+= uacce/
 obj-$(CONFIG_XILINX_SDFEC)	+= xilinx_sdfec.o
diff --git a/drivers/misc/uacce/Kconfig b/drivers/misc/uacce/Kconfig
new file mode 100644
index 0000000..5e39b60
--- /dev/null
+++ b/drivers/misc/uacce/Kconfig
@@ -0,0 +1,13 @@
+config UACCE
+	tristate "Accelerator Framework for User Land"
+	depends on IOMMU_API
+	help
+	  UACCE provides interface for the user process to access the hardware
+	  without interaction with the kernel space in data path.
+
+	  The user-space interface is described in
+	  include/uapi/misc/uacce/uacce.h
+
+	  See Documentation/misc-devices/uacce.rst for more details.
+
+	  If you don't know what to do here, say N.
diff --git a/drivers/misc/uacce/Makefile b/drivers/misc/uacce/Makefile
new file mode 100644
index 0000000..5b4374e
--- /dev/null
+++ b/drivers/misc/uacce/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+obj-$(CONFIG_UACCE) += uacce.o
diff --git a/drivers/misc/uacce/uacce.c b/drivers/misc/uacce/uacce.c
new file mode 100644
index 0000000..2b6b038
--- /dev/null
+++ b/drivers/misc/uacce/uacce.c
@@ -0,0 +1,574 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include <linux/compat.h>
+#include <linux/dma-iommu.h>
+#include <linux/module.h>
+#include <linux/poll.h>
+#include <linux/uacce.h>
+
+static struct class *uacce_class;
+static dev_t uacce_devt;
+static DEFINE_MUTEX(uacce_mutex);
+static DEFINE_XARRAY_ALLOC(uacce_xa);
+
+static int uacce_start_queue(struct uacce_queue *q)
+{
+	int ret = -EINVAL;
+
+	mutex_lock(&uacce_mutex);
+
+	if (q->state != UACCE_Q_INIT)
+		goto out_with_lock;
+
+	if (q->uacce->ops->start_queue) {
+		ret = q->uacce->ops->start_queue(q);
+		if (ret < 0)
+			goto out_with_lock;
+	}
+
+	q->state = UACCE_Q_STARTED;
+	mutex_unlock(&uacce_mutex);
+
+	return 0;
+
+out_with_lock:
+	mutex_unlock(&uacce_mutex);
+	return ret;
+}
+
+static int uacce_put_queue(struct uacce_queue *q)
+{
+	struct uacce_device *uacce = q->uacce;
+
+	mutex_lock(&uacce_mutex);
+
+	if (q->state == UACCE_Q_ZOMBIE)
+		goto out;
+
+	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;
+out:
+	mutex_unlock(&uacce_mutex);
+
+	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;
+
+	switch (cmd) {
+	case UACCE_CMD_START_Q:
+		return uacce_start_queue(q);
+
+	case UACCE_CMD_PUT_Q:
+		return uacce_put_queue(q);
+
+	default:
+		if (!uacce->ops->ioctl)
+			return -EINVAL;
+
+		return uacce->ops->ioctl(q, cmd, arg);
+	}
+}
+
+#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_sva_exit(struct device *dev, struct iommu_sva *handle,
+			  void *data)
+{
+	struct uacce_device *uacce = data;
+	struct uacce_queue *q;
+
+	mutex_lock(&uacce->q_lock);
+	list_for_each_entry(q, &uacce->qs, list) {
+		if (q->pid == task_pid_nr(current))
+			uacce_put_queue(q);
+	}
+	mutex_unlock(&uacce->q_lock);
+
+	return 0;
+}
+
+static struct iommu_sva_ops uacce_sva_ops = {
+	.mm_exit = uacce_sva_exit,
+};
+
+static int uacce_fops_open(struct inode *inode, struct file *filep)
+{
+	struct iommu_sva *handle = NULL;
+	struct uacce_device *uacce;
+	struct uacce_queue *q;
+	int ret = 0;
+	int pasid = 0;
+
+	uacce = xa_load(&uacce_xa, iminor(inode));
+	if (!uacce)
+		return -ENODEV;
+
+	if (!try_module_get(uacce->pdev->driver->owner))
+		return -ENODEV;
+
+	q = kzalloc(sizeof(struct uacce_queue), GFP_KERNEL);
+	if (!q) {
+		ret = -ENOMEM;
+		goto out_with_module;
+	}
+
+	if (uacce->flags & UACCE_DEV_SVA) {
+		handle = iommu_sva_bind_device(uacce->pdev, current->mm, uacce);
+		if (IS_ERR(handle))
+			goto out_with_mem;
+
+		ret = iommu_sva_set_ops(handle, &uacce_sva_ops);
+		if (ret)
+			goto out_unbind;
+
+		pasid = iommu_sva_get_pasid(handle);
+		if (pasid == IOMMU_PASID_INVALID)
+			goto out_unbind;
+	}
+
+	if (uacce->ops->get_queue) {
+		ret = uacce->ops->get_queue(uacce, pasid, q);
+		if (ret < 0)
+			goto out_unbind;
+	}
+
+	q->pid = task_pid_nr(current);
+	q->pasid = pasid;
+	q->handle = handle;
+	q->uacce = uacce;
+	memset(q->qfrs, 0, sizeof(q->qfrs));
+	init_waitqueue_head(&q->wait);
+	filep->private_data = q;
+	q->state = UACCE_Q_INIT;
+
+	mutex_lock(&uacce->q_lock);
+	list_add(&q->list, &uacce->qs);
+	mutex_unlock(&uacce->q_lock);
+
+	return 0;
+
+out_unbind:
+	if (uacce->flags & UACCE_DEV_SVA)
+		iommu_sva_unbind_device(handle);
+out_with_mem:
+	kfree(q);
+out_with_module:
+	module_put(uacce->pdev->driver->owner);
+	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;
+
+	uacce_put_queue(q);
+
+	if (uacce->flags & UACCE_DEV_SVA)
+		iommu_sva_unbind_device(q->handle);
+
+	mutex_lock(&uacce->q_lock);
+	list_del(&q->list);
+	mutex_unlock(&uacce->q_lock);
+	kfree(q);
+	module_put(uacce->pdev->driver->owner);
+
+	return 0;
+}
+
+static void uacce_vma_close(struct vm_area_struct *vma)
+{
+	struct uacce_queue *q = vma->vm_private_data;
+	enum uacce_qfrt type = 0;
+
+	if (vma->vm_pgoff < UACCE_QFRT_MAX)
+		type = vma->vm_pgoff;
+
+	kfree(q->qfrs[type]);
+}
+
+static const struct vm_operations_struct uacce_vm_ops = {
+	.close = uacce_vma_close,
+};
+
+static struct uacce_qfile_region *
+uacce_create_region(struct uacce_queue *q, struct vm_area_struct *vma,
+		    enum uacce_qfrt type, unsigned int flags)
+{
+	struct uacce_device *uacce = q->uacce;
+	struct uacce_qfile_region *qfr;
+	int ret = -ENOMEM;
+
+	qfr = kzalloc(sizeof(*qfr), GFP_KERNEL);
+	if (!qfr)
+		return ERR_PTR(-ENOMEM);
+
+	qfr->type = type;
+	qfr->flags = flags;
+
+	if (vma->vm_flags & VM_READ)
+		qfr->prot |= IOMMU_READ;
+
+	if (vma->vm_flags & VM_WRITE)
+		qfr->prot |= IOMMU_WRITE;
+
+	if (flags & UACCE_QFRF_SELFMT) {
+		if (!uacce->ops->mmap) {
+			ret = -EINVAL;
+			goto err_with_qfr;
+		}
+
+		ret = uacce->ops->mmap(q, vma, qfr);
+		if (ret)
+			goto err_with_qfr;
+		return qfr;
+	}
+
+	return qfr;
+
+err_with_qfr:
+	kfree(qfr);
+	return ERR_PTR(ret);
+}
+
+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 = 0;
+	unsigned int flags = 0;
+	int ret;
+
+	if (vma->vm_pgoff < UACCE_QFRT_MAX)
+		type = vma->vm_pgoff;
+
+	vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_WIPEONFORK;
+	vma->vm_ops = &uacce_vm_ops;
+	vma->vm_private_data = q;
+
+	mutex_lock(&uacce_mutex);
+
+	if (q->qfrs[type]) {
+		ret = -EEXIST;
+		goto out_with_lock;
+	}
+
+	switch (type) {
+	case UACCE_QFRT_MMIO:
+		flags = UACCE_QFRF_SELFMT;
+		break;
+
+	case UACCE_QFRT_DUS:
+		if (uacce->flags & UACCE_DEV_SVA) {
+			flags = UACCE_QFRF_SELFMT;
+			break;
+		}
+		break;
+
+	default:
+		WARN_ON(&uacce->dev);
+		break;
+	}
+
+	qfr = uacce_create_region(q, vma, type, flags);
+	if (IS_ERR(qfr)) {
+		ret = PTR_ERR(qfr);
+		goto out_with_lock;
+	}
+	q->qfrs[type] = qfr;
+
+	mutex_unlock(&uacce_mutex);
+
+	return 0;
+
+out_with_lock:
+	mutex_unlock(&uacce_mutex);
+	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_wait(file, &q->wait, wait);
+	if (uacce->ops->is_q_updated && uacce->ops->is_q_updated(q))
+		return EPOLLIN | EPOLLRDNORM;
+
+	return 0;
+}
+
+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 id_show(struct device *dev,
+		       struct device_attribute *attr, char *buf)
+{
+	struct uacce_device *uacce = to_uacce_device(dev);
+
+	return sprintf(buf, "%d\n", uacce->dev_id);
+}
+
+static ssize_t api_show(struct device *dev,
+			struct device_attribute *attr, char *buf)
+{
+	struct uacce_device *uacce = to_uacce_device(dev);
+
+	return sprintf(buf, "%s\n", uacce->api_ver);
+}
+
+static ssize_t numa_distance_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct uacce_device *uacce = to_uacce_device(dev);
+	int distance;
+
+	distance = node_distance(smp_processor_id(), uacce->pdev->numa_node);
+
+	return sprintf(buf, "%d\n", abs(distance));
+}
+
+static ssize_t node_id_show(struct device *dev,
+			    struct device_attribute *attr, char *buf)
+{
+	struct uacce_device *uacce = to_uacce_device(dev);
+	int node_id;
+
+	node_id = dev_to_node(uacce->pdev);
+
+	return sprintf(buf, "%d\n", node_id);
+}
+
+static ssize_t flags_show(struct device *dev,
+			  struct device_attribute *attr, char *buf)
+{
+	struct uacce_device *uacce = to_uacce_device(dev);
+
+	return sprintf(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);
+	int val = 0;
+
+	if (uacce->ops->get_available_instances)
+		val = uacce->ops->get_available_instances(uacce);
+
+	return sprintf(buf, "%d\n", val);
+}
+
+static ssize_t algorithms_show(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	struct uacce_device *uacce = to_uacce_device(dev);
+
+	return sprintf(buf, "%s", uacce->algs);
+}
+
+static ssize_t qfrt_mmio_size_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct uacce_device *uacce = to_uacce_device(dev);
+
+	return sprintf(buf, "%lu\n",
+		       uacce->qf_pg_size[UACCE_QFRT_MMIO] << PAGE_SHIFT);
+}
+
+static ssize_t qfrt_dus_size_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct uacce_device *uacce = to_uacce_device(dev);
+
+	return sprintf(buf, "%lu\n",
+		       uacce->qf_pg_size[UACCE_QFRT_DUS] << PAGE_SHIFT);
+}
+
+static DEVICE_ATTR_RO(id);
+static DEVICE_ATTR_RO(api);
+static DEVICE_ATTR_RO(numa_distance);
+static DEVICE_ATTR_RO(node_id);
+static DEVICE_ATTR_RO(flags);
+static DEVICE_ATTR_RO(available_instances);
+static DEVICE_ATTR_RO(algorithms);
+static DEVICE_ATTR_RO(qfrt_mmio_size);
+static DEVICE_ATTR_RO(qfrt_dus_size);
+
+static struct attribute *uacce_dev_attrs[] = {
+	&dev_attr_id.attr,
+	&dev_attr_api.attr,
+	&dev_attr_node_id.attr,
+	&dev_attr_numa_distance.attr,
+	&dev_attr_flags.attr,
+	&dev_attr_available_instances.attr,
+	&dev_attr_algorithms.attr,
+	&dev_attr_qfrt_mmio_size.attr,
+	&dev_attr_qfrt_dus_size.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(uacce_dev);
+
+static void uacce_release(struct device *dev)
+{
+	struct uacce_device *uacce = to_uacce_device(dev);
+
+	kfree(uacce);
+}
+
+/**
+ * uacce_register - register an accelerator
+ * @parent: pointer of uacce parent device
+ * @interface: pointer of uacce_interface for register
+ */
+struct uacce_device *uacce_register(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);
+
+	if (flags & UACCE_DEV_SVA) {
+		ret = iommu_dev_enable_feature(parent, IOMMU_DEV_FEAT_SVA);
+		if (ret)
+			flags &= ~UACCE_DEV_SVA;
+	}
+
+	uacce->pdev = 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;
+
+	uacce->cdev = cdev_alloc();
+	if (!uacce->cdev) {
+		ret = -ENOMEM;
+		goto err_with_xa;
+	}
+
+	INIT_LIST_HEAD(&uacce->qs);
+	mutex_init(&uacce->q_lock);
+	uacce->cdev->ops = &uacce_fops;
+	uacce->cdev->owner = THIS_MODULE;
+	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->pdev;
+	uacce->dev.release = uacce_release;
+	dev_set_name(&uacce->dev, "%s-%d", interface->name, uacce->dev_id);
+	ret = cdev_device_add(uacce->cdev, &uacce->dev);
+	if (ret)
+		goto err_with_xa;
+
+	return uacce;
+
+err_with_xa:
+	if (uacce->cdev)
+		cdev_del(uacce->cdev);
+	xa_erase(&uacce_xa, uacce->dev_id);
+err_with_uacce:
+	if (flags & UACCE_DEV_SVA)
+		iommu_dev_disable_feature(uacce->pdev, IOMMU_DEV_FEAT_SVA);
+	kfree(uacce);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(uacce_register);
+
+/**
+ * uacce_unregister - unregisters an accelerator
+ * @uacce: the accelerator to unregister
+ */
+void uacce_unregister(struct uacce_device *uacce)
+{
+	if (!uacce)
+		return;
+
+	mutex_lock(&uacce->q_lock);
+	if (!list_empty(&uacce->qs)) {
+		struct uacce_queue *q;
+
+		list_for_each_entry(q, &uacce->qs, list) {
+			uacce_put_queue(q);
+			if (uacce->flags & UACCE_DEV_SVA)
+				iommu_sva_unbind_device(q->handle);
+		}
+	}
+	mutex_unlock(&uacce->q_lock);
+
+	if (uacce->flags & UACCE_DEV_SVA)
+		iommu_dev_disable_feature(uacce->pdev, IOMMU_DEV_FEAT_SVA);
+
+	cdev_device_del(uacce->cdev, &uacce->dev);
+	xa_erase(&uacce_xa, uacce->dev_id);
+	put_device(&uacce->dev);
+}
+EXPORT_SYMBOL_GPL(uacce_unregister);
+
+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;
+	}
+
+	return 0;
+}
+
+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");
diff --git a/include/linux/uacce.h b/include/linux/uacce.h
new file mode 100644
index 0000000..04c8643
--- /dev/null
+++ b/include/linux/uacce.h
@@ -0,0 +1,163 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef _LINUX_UACCE_H
+#define _LINUX_UACCE_H
+
+#include <linux/cdev.h>
+#include <uapi/misc/uacce/uacce.h>
+
+#define UACCE_NAME		"uacce"
+#define UACCE_QFRT_MAX		16
+#define UACCE_MAX_NAME_SIZE	64
+
+struct uacce_queue;
+struct uacce_device;
+
+/**
+ * enum uacce_qfr_flag: queue file flag:
+ * @UACCE_QFRF_SELFMT: self maintained qfr
+ */
+enum uacce_qfr_flag {
+	UACCE_QFRF_SELFMT = BIT(0),
+};
+
+/**
+ * struct uacce_qfile_region - structure of queue file region
+ * @type: type of the qfr
+ * @flags: flags of qfr
+ * @prot: qfr protection flag
+ */
+struct uacce_qfile_region {
+	enum uacce_qfrt type;
+	enum uacce_qfr_flag flags;
+	u32 prot;
+};
+
+/**
+ * struct uacce_ops - uacce device operations
+ * @get_available_instances:  get available instances left of the device
+ * @get_queue: get a queue from the device
+ * @put_queue: free a queue to the device
+ * @start_queue: make the queue start work after get_queue
+ * @stop_queue: make the queue stop work before put_queue
+ * @is_q_updated: check whether the task is finished
+ * @mask_notify: mask the task irq of queue
+ * @mmap: mmap addresses of queue to user space
+ * @reset: reset the uacce device
+ * @reset_queue: reset the queue
+ * @ioctl: ioctl for user space users of the queue
+ */
+struct uacce_ops {
+	int (*get_available_instances)(struct uacce_device *uacce);
+	int (*get_queue)(struct uacce_device *uacce, unsigned long arg,
+			 struct uacce_queue *q);
+	void (*put_queue)(struct uacce_queue *q);
+	int (*start_queue)(struct uacce_queue *q);
+	void (*stop_queue)(struct uacce_queue *q);
+	int (*is_q_updated)(struct uacce_queue *q);
+	void (*mask_notify)(struct uacce_queue *q, int event_mask);
+	int (*mmap)(struct uacce_queue *q, struct vm_area_struct *vma,
+		    struct uacce_qfile_region *qfr);
+	int (*reset)(struct uacce_device *uacce);
+	int (*reset_queue)(struct uacce_queue *q);
+	long (*ioctl)(struct uacce_queue *q, unsigned int cmd,
+		      unsigned long arg);
+};
+
+/**
+ * struct uacce_interface
+ * @name: the uacce device name.  Will show up in sysfs
+ * @flags: uacce device attributes
+ * @ops: pointer to the struct uacce_ops
+ *
+ * This structure is used for the uacce_register()
+ */
+struct uacce_interface {
+	char name[UACCE_MAX_NAME_SIZE];
+	enum uacce_dev_flag flags;
+	struct uacce_ops *ops;
+};
+
+enum uacce_q_state {
+	UACCE_Q_INIT,
+	UACCE_Q_STARTED,
+	UACCE_Q_ZOMBIE,
+};
+
+/**
+ * struct uacce_queue
+ * @uacce: pointer to uacce
+ * @priv: private pointer
+ * @wait: wait queue head
+ * @pasid: pasid of the queue
+ * @pid: pid of the process using the queue
+ * @handle: iommu_sva handle return from iommu_sva_bind_device
+ * @list: queue list
+ * @qfrs: pointer of qfr regions
+ * @state: queue state machine
+ */
+struct uacce_queue {
+	struct uacce_device *uacce;
+	void *priv;
+	wait_queue_head_t wait;
+	int pasid;
+	pid_t pid;
+	struct iommu_sva *handle;
+	struct list_head list;
+	struct uacce_qfile_region *qfrs[UACCE_QFRT_MAX];
+	enum uacce_q_state state;
+};
+
+/**
+ * struct uacce_device
+ * @algs: supported algorithms
+ * @api_ver: api version
+ * @qf_pg_size: page size of the queue file regions
+ * @ops: pointer to the struct uacce_ops
+ * @pdev: pointer to the parent device
+ * @is_vf: whether virtual function
+ * @flags: uacce attributes
+ * @dev_id: id of the uacce device
+ * @prot: uacce protection flag
+ * @cdev: cdev of the uacce
+ * @dev: dev of the uacce
+ * @priv: private pointer of the uacce
+ * @qs: list head of queue->list
+ * @q_lock: lock for qs
+ */
+struct uacce_device {
+	const char *algs;
+	const char *api_ver;
+	unsigned long qf_pg_size[UACCE_QFRT_MAX];
+	struct uacce_ops *ops;
+	struct device *pdev;
+	bool is_vf;
+	u32 flags;
+	u32 dev_id;
+	u32 prot;
+	struct cdev *cdev;
+	struct device dev;
+	void *priv;
+	struct list_head qs;
+	struct mutex q_lock;
+};
+
+#if IS_ENABLED(CONFIG_UACCE)
+
+struct uacce_device *uacce_register(struct device *parent,
+				    struct uacce_interface *interface);
+void uacce_unregister(struct uacce_device *uacce);
+
+#else /* CONFIG_UACCE */
+
+static inline
+struct uacce_device *uacce_register(struct device *parent,
+				    struct uacce_interface *interface)
+{
+	return ERR_PTR(-ENODEV);
+}
+
+static inline void uacce_unregister(struct uacce_device *uacce) {}
+
+#endif /* CONFIG_UACCE */
+
+#endif /* _LINUX_UACCE_H */
diff --git a/include/uapi/misc/uacce/uacce.h b/include/uapi/misc/uacce/uacce.h
new file mode 100644
index 0000000..a4f9378
--- /dev/null
+++ b/include/uapi/misc/uacce/uacce.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+#ifndef _UAPIUUACCE_H
+#define _UAPIUUACCE_H
+
+#include <linux/types.h>
+#include <linux/ioctl.h>
+
+/* UACCE_CMD_START_Q: Start the queue */
+#define UACCE_CMD_START_Q	_IO('W', 0)
+
+/**
+ * UACCE_CMD_PUT_Q:
+ * User actively stop queue and free queue resource immediately
+ * Optimization method since close fd may delay
+ */
+#define UACCE_CMD_PUT_Q		_IO('W', 1)
+
+/**
+ * enum uacce_dev_flag: Device flags:
+ * @UACCE_DEV_SVA: Shared Virtual Addresses
+ *		   Support PASID
+ *		   Support device page faults (PCI PRI or SMMU Stall)
+ */
+enum uacce_dev_flag {
+	UACCE_DEV_SVA = BIT(0),
+};
+
+/**
+ * enum uacce_qfrt: qfrt type
+ * @UACCE_QFRT_MMIO: device mmio region
+ * @UACCE_QFRT_DUS: device user share region
+ */
+enum uacce_qfrt {
+	UACCE_QFRT_MMIO = 0,
+	UACCE_QFRT_DUS = 1,
+};
+
+#endif
-- 
2.7.4

Powered by blists - more mailing lists