[PATCH v2 1/9] s390/cio: Squash cp_free() and cp_unpin_free()

Eric Farman
2019-06-06T20:28:40Z

The routine cp_free() does nothing but call cp_unpin_free(), and while
most places call cp_free() there is one caller of cp_unpin_free() used
when the cp is guaranteed to have not been marked initialized.

This seems like a dubious way to make a distinction, so let's combine
these routines and make cp_free() do all the work.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
---
The RFC version of this patch received r-b's from Farhan [1] and
Pierre [2]. This patch is almost identical to that one, but I
opted to not include those tags because of the cp->initialized
check that now has an impact here. I still think this patch makes
sense, but want them (well, Farhan) to have a chance to look it
over since it's been six or seven months.

[1] https://patchwork.kernel.org/comment/22310411/
[2] https://patchwork.kernel.org/comment/22317927/
---
drivers/s390/cio/vfio_ccw_cp.c | 36 +++++++++++++++-------------------
1 file changed, 16 insertions(+), 20 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c
index f73cfcfdd032..47cd7f94f42f 100644
--- a/drivers/s390/cio/vfio_ccw_cp.c
+++ b/drivers/s390/cio/vfio_ccw_cp.c
@@ -412,23 +412,6 @@ static void ccwchain_cda_free(struct ccwchain *chain, int idx)
kfree((void *)(u64)ccw->cda);
}

-/* Unpin the pages then free the memory resources. */
-static void cp_unpin_free(struct channel_program *cp)
-{
- struct ccwchain *chain, *temp;
- int i;
-
- cp->initialized = false;
- list_for_each_entry_safe(chain, temp, &cp->ccwchain_list, next) {
- for (i = 0; i < chain->ch_len; i++) {
- pfn_array_table_unpin_free(chain->ch_pat + i,
- cp->mdev);
- ccwchain_cda_free(chain, i);
- }
- ccwchain_free(chain);
- }
-}
-
/**
* ccwchain_calc_length - calculate the length of the ccw chain.
* @iova: guest physical address of the target ccw chain
@@ -796,7 +779,7 @@ int cp_init(struct channel_program *cp, struct device *mdev, union orb *orb)
/* Now loop for its TICs. */
ret = ccwchain_loop_tic(chain, cp);
if (ret)
- cp_unpin_free(cp);
+ cp_free(cp);
/* It is safe to force: if not set but idals used
* ccwchain_calc_length returns an error.
*/
@@ -819,8 +802,21 @@ int cp_init(struct channel_program *cp, struct device *mdev, union orb *orb)
*/
void cp_free(struct channel_program *cp)
{
- if (cp->initialized)
- cp_unpin_free(cp);
+ struct ccwchain *chain, *temp;
+ int i;
+
+ if (!cp->initialized)
+ return;
+
+ cp->initialized = false;
+ list_for_each_entry_safe(chain, temp, &cp->ccwchain_list, next) {
+ for (i = 0; i < chain->ch_len; i++) {
+ pfn_array_table_unpin_free(chain->ch_pat + i,
+ cp->mdev);
+ ccwchain_cda_free(chain, i);
+ }
+ ccwchain_free(chain);
+ }
}

/**
--
2.17.1