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Subject[PATCH v2 3/4] staging: kpc2000: kpc_dma: Convert get_user_pages() --> pin_user_pages()
Date
In 2019, we introduced pin_user_pages*() and now we are converting
get_user_pages*() to the new API as appropriate. [1] & [2] could
be referred for more information. This is case 2 as per document [1].

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

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

Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Bharath Vedartham <linux.bhar@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
---
drivers/staging/kpc2000/kpc_dma/fileops.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/staging/kpc2000/kpc_dma/fileops.c b/drivers/staging/kpc2000/kpc_dma/fileops.c
index 08d90a6..8cd20ad 100644
--- a/drivers/staging/kpc2000/kpc_dma/fileops.c
+++ b/drivers/staging/kpc2000/kpc_dma/fileops.c
@@ -76,10 +76,10 @@ static int kpc_dma_transfer(struct dev_private_data *priv,

// Lock the user buffer pages in memory, and hold on to the page pointers (for the sglist)
mmap_read_lock(current->mm); /* get memory map semaphore */
- rv = get_user_pages(iov_base, acd->page_count, FOLL_TOUCH | FOLL_WRITE | FOLL_GET, acd->user_pages, NULL);
+ rv = pin_user_pages(iov_base, acd->page_count, FOLL_TOUCH | FOLL_WRITE, acd->user_pages, NULL);
mmap_read_unlock(current->mm); /* release the semaphore */
if (rv != acd->page_count) {
- dev_err(&priv->ldev->pldev->dev, "Couldn't get_user_pages (%d)\n", rv);
+ dev_err(&priv->ldev->pldev->dev, "Couldn't pin_user_pages (%d)\n", rv);
goto err_get_user_pages;
}

@@ -189,13 +189,11 @@ static int kpc_dma_transfer(struct dev_private_data *priv,
sg_free_table(&acd->sgt);
err_dma_map_sg:
err_alloc_sg_table:
- for (i = 0 ; i < acd->page_count ; i++)
- put_page(acd->user_pages[i]);
+ unpin_user_pages(acd->user_pages, acd->page_count);

err_get_user_pages:
if (rv > 0) {
- for (i = 0; i < rv; i++)
- put_pages(acd->user_pages[i]);
+ unpin_user_pages(acd->user_pages, rv);
rv = -EFAULT;
}
kfree(acd->user_pages);
@@ -222,8 +220,7 @@ void transfer_complete_cb(struct aio_cb_data *acd, size_t xfr_count, u32 flags)
set_page_dirty_lock(acd->user_pages[i]);
}

- for (i = 0 ; i < acd->page_count ; i++)
- put_page(acd->user_pages[i]);
+ unpin_user_pages(acd->user_pages, acd->page_count);

sg_free_table(&acd->sgt);

--
1.9.1
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