blob: bdc2e6fda782146c8dedef1cc7db6dabc41b6146 [file] [log] [blame]
// 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 dev_t uacce_devt;
static DEFINE_XARRAY_ALLOC(uacce_xa);
static const struct class uacce_class = {
.name = UACCE_NAME,
};
/*
* 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;
ret = class_register(&uacce_class);
if (ret)
return ret;
ret = alloc_chrdev_region(&uacce_devt, 0, MINORMASK, UACCE_NAME);
if (ret)
class_unregister(&uacce_class);
return ret;
}
static __exit void uacce_exit(void)
{
unregister_chrdev_region(uacce_devt, MINORMASK);
class_unregister(&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");