On 2021/1/21 17:44, Greg Kroah-Hartman wrote:
> On Thu, Jan 21, 2021 at 05:09:14PM +0800, Zhou Wang wrote:
>> When IO page fault happens, DMA performance will be affected. Pin user page
>> can avoid IO page fault, this patch introduces a new char device named
>> /dev/uacce_ctrl to help to maintain pin/unpin pages. User space can do
>> pin/unpin pages by ioctls of an open file of /dev/uacce_ctrl, all pinned
>> pages under one file will be unpinned in file release process.
>>
>> Signed-off-by: Zhou Wang <wangzhou1@xxxxxxxxxxxxx>
>> Signed-off-by: Sihang Chen <chensihang1@xxxxxxxxxxxxx>
>> Suggested-by: Barry Song <song.bao.hua@xxxxxxxxxxxxx>
>> ---
>> drivers/misc/uacce/uacce.c | 172 +++++++++++++++++++++++++++++++++++++++-
>> include/uapi/misc/uacce/uacce.h | 16 ++++
>> 2 files changed, 187 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/misc/uacce/uacce.c b/drivers/misc/uacce/uacce.c
>> index d07af4e..b8ac408 100644
>> --- a/drivers/misc/uacce/uacce.c
>> +++ b/drivers/misc/uacce/uacce.c
>> @@ -2,6 +2,7 @@
>> #include <linux/compat.h>
>> #include <linux/dma-mapping.h>
>> #include <linux/iommu.h>
>> +#include <linux/miscdevice.h>
>> #include <linux/module.h>
>> #include <linux/poll.h>
>> #include <linux/slab.h>
>> @@ -12,6 +13,16 @@ static dev_t uacce_devt;
>> static DEFINE_MUTEX(uacce_mutex);
>> static DEFINE_XARRAY_ALLOC(uacce_xa);
>>
>> +struct uacce_pin_container {
>> + struct xarray array;
>> +};
>> +
>> +struct pin_pages {
>> + unsigned long first;
>> + unsigned long nr_pages;
>> + struct page **pages;
>> +};
>> +
>> static int uacce_start_queue(struct uacce_queue *q)
>> {
>> int ret = 0;
>> @@ -497,6 +508,152 @@ void uacce_remove(struct uacce_device *uacce)
>> }
>> EXPORT_SYMBOL_GPL(uacce_remove);
>>
>> +int uacce_ctrl_open(struct inode *inode, struct file *file)
>> +{
>> + struct uacce_pin_container *p;
>> +
>> + p = kzalloc(sizeof(*p), GFP_KERNEL);
>> + if (!p)
>> + return -ENOMEM;
>> + file->private_data = p;
>> +
>> + xa_init(&p->array);
>> +
>> + return 0;
>> +}
>> +
>> +int uacce_ctrl_release(struct inode *inode, struct file *file)
>> +{
>> + struct uacce_pin_container *priv = file->private_data;
>> + struct pin_pages *p;
>> + unsigned long idx;
>> +
>> + xa_for_each(&priv->array, idx, p) {
>> + unpin_user_pages(p->pages, p->nr_pages);
>> + xa_erase(&priv->array, p->first);
>> + vfree(p->pages);
>> + kfree(p);
>> + }
>> +
>> + xa_destroy(&priv->array);
>> + kfree(priv);
>> +
>> + return 0;
>> +}
>> +
>> +static int uacce_pin_page(struct uacce_pin_container *priv,
>> + struct uacce_pin_address *addr)
>> +{
>> + unsigned int flags = FOLL_FORCE | FOLL_WRITE;
>> + unsigned long first, last, nr_pages;
>> + struct page **pages;
>> + struct pin_pages *p;
>> + int ret;
>> +
>> + first = (addr->addr & PAGE_MASK) >> PAGE_SHIFT;
>> + last = ((addr->addr + addr->size - 1) & PAGE_MASK) >> PAGE_SHIFT;
>> + nr_pages = last - first + 1;
>> +
>> + pages = vmalloc(nr_pages * sizeof(struct page *));
>> + if (!pages)
>> + return -ENOMEM;
>> +
>> + p = kzalloc(sizeof(*p), GFP_KERNEL);
>> + if (!p) {
>> + ret = -ENOMEM;
>> + goto free;
>> + }
>> +
>> + ret = pin_user_pages_fast(addr->addr & PAGE_MASK, nr_pages,
>> + flags | FOLL_LONGTERM, pages);
>> + if (ret != nr_pages) {
>> + pr_err("uacce: Failed to pin page\n");
>> + goto free_p;
>> + }
>> + p->first = first;
>> + p->nr_pages = nr_pages;
>> + p->pages = pages;
>> +
>> + ret = xa_err(xa_store(&priv->array, p->first, p, GFP_KERNEL));
>> + if (ret)
>> + goto unpin_pages;
>> +
>> + return 0;
>> +
>> +unpin_pages:
>> + unpin_user_pages(pages, nr_pages);
>> +free_p:
>> + kfree(p);
>> +free:
>> + vfree(pages);
>> + return ret;
>> +}
>> +
>> +static int uacce_unpin_page(struct uacce_pin_container *priv,
>> + struct uacce_pin_address *addr)
>> +{
>> + unsigned long first, last, nr_pages;
>> + struct pin_pages *p;
>> +
>> + first = (addr->addr & PAGE_MASK) >> PAGE_SHIFT;
>> + last = ((addr->addr + addr->size - 1) & PAGE_MASK) >> PAGE_SHIFT;
>> + nr_pages = last - first + 1;
>> +
>> + /* find pin_pages */
>> + p = xa_load(&priv->array, first);
>> + if (!p)
>> + return -ENODEV;
>> +
>> + if (p->nr_pages != nr_pages)
>> + return -EINVAL;
>> +
>> + /* unpin */
>> + unpin_user_pages(p->pages, p->nr_pages);
>> +
>> + /* release resource */
>> + xa_erase(&priv->array, first);
>> + vfree(p->pages);
>> + kfree(p);
>> +
>> + return 0;
>> +}
>> +
>> +static long uacce_ctrl_unl_ioctl(struct file *filep, unsigned int cmd,
>> + unsigned long arg)
>> +{
>> + struct uacce_pin_container *p = filep->private_data;
>> + struct uacce_pin_address addr;
>> + int ret;
>> +
>> + if (copy_from_user(&addr, (void __user *)arg,
>> + sizeof(struct uacce_pin_address)))
>> + return -EFAULT;
>> +
>> + switch (cmd) {
>> + case UACCE_CMD_PIN:
>> + return uacce_pin_page(p, &addr);
>> +
>> + case UACCE_CMD_UNPIN:
>> + return uacce_unpin_page(p, &addr);
>> +
>> + default:
>> + return -EINVAL;
>> + }
>> +}
>> +
>> +static const struct file_operations uacce_ctrl_fops = {
>> + .owner = THIS_MODULE,
>> + .open = uacce_ctrl_open,
>> + .release = uacce_ctrl_release,
>> + .unlocked_ioctl = uacce_ctrl_unl_ioctl,
>> +};
>> +
>> +static struct miscdevice uacce_ctrl_miscdev = {
>> + .name = "uacce_ctrl",
>> + .minor = MISC_DYNAMIC_MINOR,
>> + .fops = &uacce_ctrl_fops,
>> +};
>> +
>> static int __init uacce_init(void)
>> {
>> int ret;
>> @@ -507,13 +664,26 @@ static int __init uacce_init(void)
>>
>> ret = alloc_chrdev_region(&uacce_devt, 0, MINORMASK, UACCE_NAME);
>> if (ret)
>> - class_destroy(uacce_class);
>> + goto destroy_class;
>> +
>> + ret = misc_register(&uacce_ctrl_miscdev);
>> + if (ret) {
>> + pr_err("uacce: ctrl dev registration failed\n");
>> + goto unregister_cdev;
>> + }
>>
>> + return 0;
>> +
>> +unregister_cdev:
>> + unregister_chrdev_region(uacce_devt, MINORMASK);
>> +destroy_class:
>> + class_destroy(uacce_class);
>> return ret;
>> }
>>
>> static __exit void uacce_exit(void)
>> {
>> + misc_deregister(&uacce_ctrl_miscdev);
>> unregister_chrdev_region(uacce_devt, MINORMASK);
>> class_destroy(uacce_class);
>> }
>> diff --git a/include/uapi/misc/uacce/uacce.h b/include/uapi/misc/uacce/uacce.h
>> index cc71856..f9e326f 100644
>> --- a/include/uapi/misc/uacce/uacce.h
>> +++ b/include/uapi/misc/uacce/uacce.h
>> @@ -35,4 +35,20 @@ enum uacce_qfrt {
>> UACCE_QFRT_DUS = 1,
>> };
>>
>> +/**
>> + * struct uacce_pin_address - Expected pin user space address and size
>> + * @addr: Address to pin
>> + * @size: Size of pin address
>> + */
>> +struct uacce_pin_address {
>> + unsigned long addr;
>> + unsigned long size;
>
> These are not valid ioctl structure members for crossing the user/kernel
> boundry. Please make them work properly (i.e. use __u64 and friends).
Got it, will modify this to __u64 together with other problems found by 0-day robot.
Thanks,
Zhou
>
> thanks,
>
> greg k-h
>
> .
>
