From 84be242dae81b36a4c696d8e7734f54d359e5cf3 Mon Sep 17 00:00:00 2001 From: John Hubbard Date: Thu, 21 May 2020 21:15:06 -0700 Subject: [PATCH] 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 Cc: Arnd Bergmann Cc: Daniel Vetter Cc: Gustavo A. R. Silva Cc: Jani Nikula Cc: dri-devel@lists.freedesktop.org Cc: linux-fbdev@vger.kernel.org Signed-off-by: John Hubbard Signed-off-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20200522041506.39638-3-jhubbard@nvidia.com --- drivers/video/fbdev/pvr2fb.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/video/fbdev/pvr2fb.c b/drivers/video/fbdev/pvr2fb.c index ceb6ef590597..2d9f69b93392 100644 --- a/drivers/video/fbdev/pvr2fb.c +++ b/drivers/video/fbdev/pvr2fb.c @@ -652,7 +652,7 @@ static ssize_t pvr2fb_write(struct fb_info *info, const char *buf, if (!pages) return -ENOMEM; - ret = get_user_pages_fast((unsigned long)buf, nr_pages, FOLL_WRITE, pages); + ret = pin_user_pages_fast((unsigned long)buf, nr_pages, FOLL_WRITE, pages); if (ret < nr_pages) { if (ret < 0) { /* @@ -712,9 +712,7 @@ out: ret = count; out_unmap: - for (i = 0; i < nr_pages; i++) - put_page(pages[i]); - + unpin_user_pages(pages, nr_pages); kfree(pages); return ret; -- 2.11.0