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>

diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c
index 76ffcc8..8205d0b 100644 (file)
--- 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;