summaryrefslogtreecommitdiffstats
path: root/drivers/misc/uacce
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/misc/uacce')
-rw-r--r--drivers/misc/uacce/Kconfig13
-rw-r--r--drivers/misc/uacce/Makefile2
-rw-r--r--drivers/misc/uacce/uacce.c648
3 files changed, 663 insertions, 0 deletions
diff --git a/drivers/misc/uacce/Kconfig b/drivers/misc/uacce/Kconfig
new file mode 100644
index 0000000000..5e39b6083b
--- /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 0000000000..5b4374e8b5
--- /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 0000000000..930c252753
--- /dev/null
+++ b/drivers/misc/uacce/uacce.c
@@ -0,0 +1,648 @@
+// 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);
+ 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;
+ q->state = UACCE_Q_INIT;
+ q->mapping = filep->f_mapping;
+ 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;
+
+ if (vma->vm_pgoff < UACCE_MAX_REGION) {
+ struct uacce_qfile_region *qfr = q->qfrs[vma->vm_pgoff];
+
+ mutex_lock(&q->mutex);
+ q->qfrs[vma->vm_pgoff] = NULL;
+ mutex_unlock(&q->mutex);
+ 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;
+
+ vm_flags_set(vma, 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 ssize_t isolate_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct uacce_device *uacce = to_uacce_device(dev);
+
+ return sysfs_emit(buf, "%d\n", uacce->ops->get_isolate_state(uacce));
+}
+
+static ssize_t isolate_strategy_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct uacce_device *uacce = to_uacce_device(dev);
+ u32 val;
+
+ val = uacce->ops->isolate_err_threshold_read(uacce);
+
+ return sysfs_emit(buf, "%u\n", val);
+}
+
+static ssize_t isolate_strategy_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct uacce_device *uacce = to_uacce_device(dev);
+ unsigned long val;
+ int ret;
+
+ if (kstrtoul(buf, 0, &val) < 0)
+ return -EINVAL;
+
+ if (val > UACCE_MAX_ERR_THRESHOLD)
+ return -EINVAL;
+
+ ret = uacce->ops->isolate_err_threshold_write(uacce, val);
+ if (ret)
+ return ret;
+
+ return count;
+}
+
+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 DEVICE_ATTR_RO(isolate);
+static DEVICE_ATTR_RW(isolate_strategy);
+
+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,
+ &dev_attr_isolate.attr,
+ &dev_attr_isolate_strategy.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;
+
+ if (attr == &dev_attr_isolate_strategy.attr &&
+ (!uacce->ops->isolate_err_threshold_read &&
+ !uacce->ops->isolate_err_threshold_write))
+ return 0;
+
+ if (attr == &dev_attr_isolate.attr && !uacce->ops->get_isolate_state)
+ 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;
+
+ /*
+ * 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);
+
+ /*
+ * unmap remaining mapping from user space, preventing user still
+ * access the mmaped area while parent device is already removed
+ */
+ unmap_mapping_range(q->mapping, 0, 0, 1);
+ }
+
+ /* 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(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");