2022-11-07 16:30:26

by David Hildenbrand

Subject: [PATCH RFC 19/19] habanalabs: remove FOLL_FORCE usage

FOLL_FORCE is really only for debugger access. As we unpin the pinned pages
using unpin_user_pages_dirty_lock(true), the assumption is that all these
pages are writable.

FOLL_FORCE in this case seems to be due to copy-and-past from other
drivers. Let's just remove it.

Cc: Oded Gabbay <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Signed-off-by: David Hildenbrand <[email protected]>
---
drivers/misc/habanalabs/common/memory.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/misc/habanalabs/common/memory.c b/drivers/misc/habanalabs/common/memory.c
index ef28f3b37b93..e35cca96bbef 100644
--- a/drivers/misc/habanalabs/common/memory.c
+++ b/drivers/misc/habanalabs/common/memory.c
@@ -2312,8 +2312,7 @@ static int get_user_memory(struct hl_device *hdev, u64 addr, u64 size,
if (!userptr->pages)
return -ENOMEM;

- rc = pin_user_pages_fast(start, npages,
- FOLL_FORCE | FOLL_WRITE | FOLL_LONGTERM,
+ rc = pin_user_pages_fast(start, npages, FOLL_WRITE | FOLL_LONGTERM,
userptr->pages);

if (rc != npages) {
--
2.38.1

2022-11-07 22:12:07

by Oded Gabbay

Subject: Re: [PATCH RFC 19/19] habanalabs: remove FOLL_FORCE usage

On Mon, Nov 7, 2022 at 6:19 PM David Hildenbrand <[email protected]> wrote:
>
> FOLL_FORCE is really only for debugger access. As we unpin the pinned pages
> using unpin_user_pages_dirty_lock(true), the assumption is that all these
> pages are writable.
>
> FOLL_FORCE in this case seems to be due to copy-and-past from other
> drivers. Let's just remove it.
>
> Cc: Oded Gabbay <[email protected]>
> Cc: Arnd Bergmann <[email protected]>
> Cc: Greg Kroah-Hartman <[email protected]>
> Signed-off-by: David Hildenbrand <[email protected]>
> ---
> drivers/misc/habanalabs/common/memory.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/misc/habanalabs/common/memory.c b/drivers/misc/habanalabs/common/memory.c
> index ef28f3b37b93..e35cca96bbef 100644
> --- a/drivers/misc/habanalabs/common/memory.c
> +++ b/drivers/misc/habanalabs/common/memory.c
> @@ -2312,8 +2312,7 @@ static int get_user_memory(struct hl_device *hdev, u64 addr, u64 size,
> if (!userptr->pages)
> return -ENOMEM;
>
> - rc = pin_user_pages_fast(start, npages,
> - FOLL_FORCE | FOLL_WRITE | FOLL_LONGTERM,
> + rc = pin_user_pages_fast(start, npages, FOLL_WRITE | FOLL_LONGTERM,
> userptr->pages);
>
> if (rc != npages) {
> --
> 2.38.1
>
>
Acked-by: Oded Gabbay <[email protected]>
Thanks,
Oded