vfio-ccw: Rearrange IDAL allocation in direct CCW

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>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20190606202831.44135-9-farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>

1 files 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;