[PATCH v2 4/4] staging: kpc2000: kpc_dma: Remove additional goto statements

From: Souptick Joarder
Date: Tue Jun 30 2020 - 03:44:38 EST


As 3 goto level referring to same common code, those can be
accomodated with a single goto level and renameing it to
unpin_pages. Set the -ERRNO when returning partial mapped
pages in more appropriate place.

Signed-off-by: Souptick Joarder <jrdr.linux@xxxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Bharath Vedartham <linux.bhar@xxxxxxxxx>
Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
drivers/staging/kpc2000/kpc_dma/fileops.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/staging/kpc2000/kpc_dma/fileops.c b/drivers/staging/kpc2000/kpc_dma/fileops.c
index 8cd20ad..d21a4fd 100644
--- a/drivers/staging/kpc2000/kpc_dma/fileops.c
+++ b/drivers/staging/kpc2000/kpc_dma/fileops.c
@@ -35,7 +35,7 @@ static int kpc_dma_transfer(struct dev_private_data *priv,
unsigned long iov_base, size_t iov_len)
{
unsigned int i = 0;
- int rv = 0;
+ int rv = 0, nr_pages = 0;
struct kpc_dma_device *ldev;
struct aio_cb_data *acd;
DECLARE_COMPLETION_ONSTACK(done);
@@ -79,22 +79,27 @@ static int kpc_dma_transfer(struct dev_private_data *priv,
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) {
+ nr_pages = rv;
+ if (rv > 0)
+ rv = -EFAULT;
+
dev_err(&priv->ldev->pldev->dev, "Couldn't pin_user_pages (%d)\n", rv);
- goto err_get_user_pages;
+ goto unpin_pages;
}
+ nr_pages = acd->page_count;

// Allocate and setup the sg_table (scatterlist entries)
rv = sg_alloc_table_from_pages(&acd->sgt, acd->user_pages, acd->page_count, iov_base & (PAGE_SIZE - 1), iov_len, GFP_KERNEL);
if (rv) {
dev_err(&priv->ldev->pldev->dev, "Couldn't alloc sg_table (%d)\n", rv);
- goto err_alloc_sg_table;
+ goto unpin_pages;
}

// Setup the DMA mapping for all the sg entries
acd->mapped_entry_count = dma_map_sg(&ldev->pldev->dev, acd->sgt.sgl, acd->sgt.nents, ldev->dir);
if (acd->mapped_entry_count <= 0) {
dev_err(&priv->ldev->pldev->dev, "Couldn't dma_map_sg (%d)\n", acd->mapped_entry_count);
- goto err_dma_map_sg;
+ goto unpin_pages;
}

// Calculate how many descriptors are actually needed for this transfer.
@@ -187,15 +192,10 @@ static int kpc_dma_transfer(struct dev_private_data *priv,
unlock_engine(ldev);
dma_unmap_sg(&ldev->pldev->dev, acd->sgt.sgl, acd->sgt.nents, ldev->dir);
sg_free_table(&acd->sgt);
- err_dma_map_sg:
- err_alloc_sg_table:
- unpin_user_pages(acd->user_pages, acd->page_count);

- err_get_user_pages:
- if (rv > 0) {
- unpin_user_pages(acd->user_pages, rv);
- rv = -EFAULT;
- }
+ unpin_pages:
+ if (nr_pages > 0)
+ unpin_user_pages(acd->user_pages, nr_pages);
kfree(acd->user_pages);
err_alloc_userpages:
kfree(acd);
--
1.9.1