video: fbdev: convert get_user_pages() --> pin_user_pages()

This code was using get_user_pages*(), in a "Case 2" scenario
(DMA/RDMA), using the categorization from [1]. That means that it's
time to convert the get_user_pages*() + put_page() calls to
pin_user_pages*() + unpin_user_pages() calls.

There is some helpful background in [2]: basically, this is a small
part of fixing a long-standing disconnect between pinning pages, and
file systems' use of those pages.

[1] Documentation/core-api/pin_user_pages.rst

[2] "Explicit pinning of user-space pages":
    https://lwn.net/Articles/807108/

Cc: Bartlomiej Zolnierkiewicz <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: Gustavo A. R. Silva <[email protected]>
Cc: Jani Nikula <[email protected]>
Cc: [email protected]
Cc: [email protected]
Signed-off-by: John Hubbard <[email protected]>
Signed-off-by: Sam Ravnborg <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

0 files changed, 0 insertions, 0 deletions