On Fri, Aug 09, 2019 at 05:41:05PM +0800, Lijun Ou wrote:
> From: Yangyang Li <liyangyang20@xxxxxxxxxx>
>
> In the reset scenario, if the kernel receives the reset signal,
> it needs to notify the user space to stop ring doorbell.
I doubt about it, it is racy like hell and relies on assumption that
userspace will honor such request to stop.
>
> Signed-off-by: Yangyang Li <liyangyang20@xxxxxxxxxx>
> ---
> drivers/infiniband/hw/hns/hns_roce_device.h | 4 +++
> drivers/infiniband/hw/hns/hns_roce_hw_v2.c | 52 ++++++++++++++++++++++++++++-
> drivers/infiniband/hw/hns/hns_roce_hw_v2.h | 4 +++
> drivers/infiniband/hw/hns/hns_roce_main.c | 22 ++++++------
> 4 files changed, 70 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/infiniband/hw/hns/hns_roce_device.h b/drivers/infiniband/hw/hns/hns_roce_device.h
> index 32465f5..be65fce 100644
> --- a/drivers/infiniband/hw/hns/hns_roce_device.h
> +++ b/drivers/infiniband/hw/hns/hns_roce_device.h
> @@ -268,6 +268,8 @@ enum {
>
> #define PAGE_ADDR_SHIFT 12
>
> +#define HNS_ROCE_IS_RESETTING 1
> +
> struct hns_roce_uar {
> u64 pfn;
> unsigned long index;
> @@ -1043,6 +1045,8 @@ struct hns_roce_dev {
> u32 odb_offset;
> dma_addr_t tptr_dma_addr; /* only for hw v1 */
> u32 tptr_size; /* only for hw v1 */
> + struct page *reset_page; /* store reset state */
> + void *reset_kaddr; /* addr of reset page */
> const struct hns_roce_hw *hw;
> void *priv;
> struct workqueue_struct *irq_workq;
> diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
> index d33341e..138e5a8 100644
> --- a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
> +++ b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
> @@ -1867,17 +1867,49 @@ static void hns_roce_free_link_table(struct hns_roce_dev *hr_dev,
> link_tbl->table.map);
> }
>
> +static int hns_roce_v2_get_reset_page(struct hns_roce_dev *hr_dev)
> +{
> + hr_dev->reset_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
> + if (!hr_dev->reset_page)
> + return -ENOMEM;
> +
> + hr_dev->reset_kaddr = vmap(&hr_dev->reset_page, 1, VM_MAP, PAGE_KERNEL);
> + if (!hr_dev->reset_kaddr)
> + goto err_with_vmap;
> +
> + return 0;
> +
> +err_with_vmap:
> + put_page(hr_dev->reset_page);
Are you sure that pages allocated with alloc_page() are released with put_page()?
I would say with high confidence that whole this patch is wrong.
Thanks
