[PATCH v2 8/9] vfio-ccw: Rearrange IDAL allocation in direct CCW

Eric Farman
2019-06-06T20:28:41Z

This is purely deck furniture, to help understand the merge of the
direct and indirect handlers.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
---
drivers/s390/cio/vfio_ccw_cp.c | 25 +++++++++++++++----------
1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c
index 76ffcc823944..8205d0b527fc 100644
--- a/drivers/s390/cio/vfio_ccw_cp.c
+++ b/drivers/s390/cio/vfio_ccw_cp.c
@@ -537,13 +537,21 @@ static int ccwchain_fetch_direct(struct ccwchain *chain,
unsigned long *idaws;
int ret;
int bytes = 1;
- int idaw_nr = 1;
+ int idaw_nr;

ccw = chain->ch_ccw + idx;

- if (ccw->count) {
+ if (ccw->count)
bytes = ccw->count;
- idaw_nr = idal_nr_words((void *)(u64)ccw->cda, ccw->count);
+
+ /* Calculate size of IDAL */
+ idaw_nr = idal_nr_words((void *)(u64)ccw->cda, bytes);
+
+ /* Allocate an IDAL from host storage */
+ idaws = kcalloc(idaw_nr, sizeof(*idaws), GFP_DMA | GFP_KERNEL);
+ if (!idaws) {
+ ret = -ENOMEM;
+ goto out_init;
}

/*
@@ -554,7 +562,7 @@ static int ccwchain_fetch_direct(struct ccwchain *chain,
pa = chain->ch_pa + idx;
ret = pfn_array_alloc(pa, ccw->cda, bytes);
if (ret < 0)
- goto out_unpin;
+ goto out_free_idaws;

if (ccw_does_data_transfer(ccw)) {
ret = pfn_array_pin(pa, cp->mdev);
@@ -564,21 +572,18 @@ static int ccwchain_fetch_direct(struct ccwchain *chain,
pa->pa_nr = 0;
}

- /* Translate this direct ccw to a idal ccw. */
- idaws = kcalloc(idaw_nr, sizeof(*idaws), GFP_DMA | GFP_KERNEL);
- if (!idaws) {
- ret = -ENOMEM;
- goto out_unpin;
- }
ccw->cda = (__u32) virt_to_phys(idaws);
ccw->flags |= CCW_FLAG_IDA;

+ /* Populate the IDAL with pinned/translated addresses from pfn */
pfn_array_idal_create_words(pa, idaws);

return 0;

out_unpin:
pfn_array_unpin_free(pa, cp->mdev);
+out_free_idaws:
+ kfree(idaws);
out_init:
ccw->cda = 0;
return ret;
--
2.17.1