diff options
| author | John Hubbard <jhubbard@nvidia.com> | 2020-05-26 18:26:28 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-05-27 11:09:26 +0200 |
| commit | 03358b0f7bc7b5868bbb30f47224a937e2e4d6d3 (patch) | |
| tree | ee6a7882a08b15df51f0e736103b5dd754995e7f /drivers/misc | |
| parent | d25594d764613ad58656bbe74a86706204813a9f (diff) | |
misc: xilinx-sdfec: convert get_user_pages() --> pin_user_pages()
This code was using get_user_pages*(), in approximately a "Case 1"
scenario (Direct IO), 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: Derek Kiernan <derek.kiernan@xilinx.com>
Cc: Dragan Cvetic <dragan.cvetic@xilinx.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Link: https://lore.kernel.org/r/20200527012628.1100649-4-jhubbard@nvidia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc')
| -rw-r--r-- | drivers/misc/xilinx_sdfec.c | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/drivers/misc/xilinx_sdfec.c b/drivers/misc/xilinx_sdfec.c index 0ef03560b13f..92291292756a 100644 --- a/drivers/misc/xilinx_sdfec.c +++ b/drivers/misc/xilinx_sdfec.c @@ -627,12 +627,11 @@ static int xsdfec_table_write(struct xsdfec_dev *xsdfec, u32 offset, nr_pages = n; - res = get_user_pages_fast((unsigned long)src_ptr, nr_pages, 0, pages); + res = pin_user_pages_fast((unsigned long)src_ptr, nr_pages, 0, pages); if (res < nr_pages) { - if (res > 0) { - for (i = 0; i < res; i++) - put_page(pages[i]); - } + if (res > 0) + unpin_user_pages(pages, res); + return -EINVAL; } @@ -646,7 +645,7 @@ static int xsdfec_table_write(struct xsdfec_dev *xsdfec, u32 offset, reg++; } while ((reg < len) && ((reg * XSDFEC_REG_WIDTH_JUMP) % PAGE_SIZE)); - put_page(pages[i]); + unpin_user_page(pages[i]); } return 0; } |