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authorJohn Hubbard <jhubbard@nvidia.com>2020-05-26 01:17:54 +0300
committerMoritz Fischer <mdf@kernel.org>2020-06-19 04:12:06 +0300
commit55dc9b87e4a8e4d0fb1b7169bab7e23d27ba4209 (patch)
tree3f2f0e9061417f741522c5bbef8ff5a10cb4a46e /drivers/fpga
parentb3a9e3b9622ae10064826dccb4f7a52bd88c7407 (diff)
downloadlinux-55dc9b87e4a8e4d0fb1b7169bab7e23d27ba4209.tar.xz
fpga: dfl: afu: convert get_user_pages() --> pin_user_pages()
This code was using get_user_pages_fast(), in a "Case 2" scenario (DMA/RDMA), using the categorization from [1]. That means that it's time to convert the get_user_pages_fast() + put_page() calls to pin_user_pages_fast() + 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: Xu Yilun <yilun.xu@intel.com> Cc: Wu Hao <hao.wu@intel.com> Cc: Moritz Fischer <mdf@kernel.org> Cc: linux-fpga@vger.kernel.org Signed-off-by: John Hubbard <jhubbard@nvidia.com> Acked-by: Wu Hao <hao.wu@intel.com> Signed-off-by: Moritz Fischer <mdf@kernel.org>
Diffstat (limited to 'drivers/fpga')
-rw-r--r--drivers/fpga/dfl-afu-dma-region.c19
1 files changed, 5 insertions, 14 deletions
diff --git a/drivers/fpga/dfl-afu-dma-region.c b/drivers/fpga/dfl-afu-dma-region.c
index 02d8cbad1ae2..02b60fde0430 100644
--- a/drivers/fpga/dfl-afu-dma-region.c
+++ b/drivers/fpga/dfl-afu-dma-region.c
@@ -16,15 +16,6 @@
#include "dfl-afu.h"
-static void put_all_pages(struct page **pages, int npages)
-{
- int i;
-
- for (i = 0; i < npages; i++)
- if (pages[i])
- put_page(pages[i]);
-}
-
void afu_dma_region_init(struct dfl_feature_platform_data *pdata)
{
struct dfl_afu *afu = dfl_fpga_pdata_get_private(pdata);
@@ -57,22 +48,22 @@ static int afu_dma_pin_pages(struct dfl_feature_platform_data *pdata,
goto unlock_vm;
}
- pinned = get_user_pages_fast(region->user_addr, npages, FOLL_WRITE,
+ pinned = pin_user_pages_fast(region->user_addr, npages, FOLL_WRITE,
region->pages);
if (pinned < 0) {
ret = pinned;
goto free_pages;
} else if (pinned != npages) {
ret = -EFAULT;
- goto put_pages;
+ goto unpin_pages;
}
dev_dbg(dev, "%d pages pinned\n", pinned);
return 0;
-put_pages:
- put_all_pages(region->pages, pinned);
+unpin_pages:
+ unpin_user_pages(region->pages, pinned);
free_pages:
kfree(region->pages);
unlock_vm:
@@ -94,7 +85,7 @@ static void afu_dma_unpin_pages(struct dfl_feature_platform_data *pdata,
long npages = region->length >> PAGE_SHIFT;
struct device *dev = &pdata->dev->dev;
- put_all_pages(region->pages, npages);
+ unpin_user_pages(region->pages, npages);
kfree(region->pages);
account_locked_vm(current->mm, npages, false);