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| author |   John Hubbard <jhubbard@nvidia.com> | 2020-05-25 15:17:54 -0700 |
|---|---|---|
| committer |   Moritz Fischer <mdf@kernel.org> | 2020-06-18 18:12:06 -0700 |
| commit | 55dc9b87e4a8e4d0fb1b7169bab7e23d27ba4209 (patch) | |
| tree | 3f2f0e9061417f741522c5bbef8ff5a10cb4a46e /drivers/fpga | |
| parent | Linux 5.8-rc1 (diff) | |
| download | linux-dev-55dc9b87e4a8e4d0fb1b7169bab7e23d27ba4209.tar.xz linux-dev-55dc9b87e4a8e4d0fb1b7169bab7e23d27ba4209.zip | |
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.c | 19 |
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); |