| Message ID | 20190606202831.44135-7-farman@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | s390: vfio-ccw code rework | expand |
On Thu, 6 Jun 2019 22:28:28 +0200 Eric Farman <farman@linux.ibm.com> wrote: > Now that pfn_array_table[] is always an array of 1, it seems silly to > check for the very first entry in an array in the middle of two nested > loops, since we know it'll only ever happen once. > > Let's move this outside the loops to simplify things, even though > the "k" variable is still necessary. > > Signed-off-by: Eric Farman <farman@linux.ibm.com> > --- > drivers/s390/cio/vfio_ccw_cp.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c > index 86a0e76ef2b5..ab9f8f0d1b44 100644 > --- a/drivers/s390/cio/vfio_ccw_cp.c > +++ b/drivers/s390/cio/vfio_ccw_cp.c > @@ -201,11 +201,12 @@ static inline void pfn_array_table_idal_create_words( > pa = pat->pat_pa + i; > for (j = 0; j < pa->pa_nr; j++) { > idaws[k] = pa->pa_pfn[j] << PAGE_SHIFT; > - if (k == 0) > - idaws[k] += pa->pa_iova & (PAGE_SIZE - 1); > k++; > } > } > + > + /* Adjust the first IDAW, since it may not start on a page boundary */ > + idaws[0] += pat->pat_pa->pa_iova & (PAGE_SIZE - 1); > } > > Also +1 to adding a nice explaining comment :) Reviewed-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 86a0e76ef2b5..ab9f8f0d1b44 100644 --- a/drivers/s390/cio/vfio_ccw_cp.c +++ b/drivers/s390/cio/vfio_ccw_cp.c @@ -201,11 +201,12 @@ static inline void pfn_array_table_idal_create_words( pa = pat->pat_pa + i; for (j = 0; j < pa->pa_nr; j++) { idaws[k] = pa->pa_pfn[j] << PAGE_SHIFT; - if (k == 0) - idaws[k] += pa->pa_iova & (PAGE_SIZE - 1); k++; } } + + /* Adjust the first IDAW, since it may not start on a page boundary */ + idaws[0] += pat->pat_pa->pa_iova & (PAGE_SIZE - 1); }
Now that pfn_array_table[] is always an array of 1, it seems silly to check for the very first entry in an array in the middle of two nested loops, since we know it'll only ever happen once. Let's move this outside the loops to simplify things, even though the "k" variable is still necessary. Signed-off-by: Eric Farman <farman@linux.ibm.com> --- drivers/s390/cio/vfio_ccw_cp.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)