[PATCH 1/1] vfio-ccw: Enable transparent CCW IPL from DASD

From: Jared Rossi
Date: Fri Apr 17 2020 - 14:27:31 EST


Remove the explicit prefetch check when using vfio-ccw devices.
This check is not needed as all Linux channel programs are intended
to use prefetch and will be executed in the same way regardless.

Signed-off-by: Jared Rossi <jrossi@xxxxxxxxxxxxx>
---
drivers/s390/cio/vfio_ccw_cp.c | 16 ++++------------
drivers/s390/cio/vfio_ccw_cp.h | 2 +-
drivers/s390/cio/vfio_ccw_fsm.c | 6 +++---
3 files changed, 8 insertions(+), 16 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c
index 3645d1720c4b..5b47ecbb4baa 100644
--- a/drivers/s390/cio/vfio_ccw_cp.c
+++ b/drivers/s390/cio/vfio_ccw_cp.c
@@ -625,9 +625,8 @@ static int ccwchain_fetch_one(struct ccwchain *chain,
* the target channel program from @orb->cmd.iova to the new ccwchain(s).
*
* Limitations:
- * 1. Supports only prefetch enabled mode.
- * 2. Supports idal(c64) ccw chaining.
- * 3. Supports 4k idaw.
+ * 1. Supports idal(c64) ccw chaining.
+ * 2. Supports 4k idaw.
*
* Returns:
* %0 on success and a negative error value on failure.
@@ -636,13 +635,6 @@ int cp_init(struct channel_program *cp, struct device *mdev, union orb *orb)
{
int ret;

- /*
- * XXX:
- * Only support prefetch enable mode now.
- */
- if (!orb->cmd.pfch)
- return -EOPNOTSUPP;
-
INIT_LIST_HEAD(&cp->ccwchain_list);
memcpy(&cp->orb, orb, sizeof(*orb));
cp->mdev = mdev;
@@ -690,7 +682,7 @@ void cp_free(struct channel_program *cp)
}

/**
- * cp_prefetch() - translate a guest physical address channel program to
+ * cp_fetch() - translate a guest physical address channel program to
* a real-device runnable channel program.
* @cp: channel_program on which to perform the operation
*
@@ -726,7 +718,7 @@ void cp_free(struct channel_program *cp)
* Returns:
* %0 on success and a negative error value on failure.
*/
-int cp_prefetch(struct channel_program *cp)
+int cp_fetch(struct channel_program *cp)
{
struct ccwchain *chain;
int len, idx, ret;
diff --git a/drivers/s390/cio/vfio_ccw_cp.h b/drivers/s390/cio/vfio_ccw_cp.h
index ba31240ce965..a226f6e99d04 100644
--- a/drivers/s390/cio/vfio_ccw_cp.h
+++ b/drivers/s390/cio/vfio_ccw_cp.h
@@ -45,7 +45,7 @@ struct channel_program {
extern int cp_init(struct channel_program *cp, struct device *mdev,
union orb *orb);
extern void cp_free(struct channel_program *cp);
-extern int cp_prefetch(struct channel_program *cp);
+extern int cp_fetch(struct channel_program *cp);
extern union orb *cp_get_orb(struct channel_program *cp, u32 intparm, u8 lpm);
extern void cp_update_scsw(struct channel_program *cp, union scsw *scsw);
extern bool cp_iova_pinned(struct channel_program *cp, u64 iova);
diff --git a/drivers/s390/cio/vfio_ccw_fsm.c b/drivers/s390/cio/vfio_ccw_fsm.c
index 23e61aa638e4..446f9186d070 100644
--- a/drivers/s390/cio/vfio_ccw_fsm.c
+++ b/drivers/s390/cio/vfio_ccw_fsm.c
@@ -274,14 +274,14 @@ static void fsm_io_request(struct vfio_ccw_private *private,
goto err_out;
}

- io_region->ret_code = cp_prefetch(&private->cp);
+ io_region->ret_code = cp_fetch(&private->cp);
if (io_region->ret_code) {
VFIO_CCW_MSG_EVENT(2,
- "%pUl (%x.%x.%04x): cp_prefetch=%d\n",
+ "%pUl (%x.%x.%04x): cp_fetch=%d\n",
mdev_uuid(mdev), schid.cssid,
schid.ssid, schid.sch_no,
io_region->ret_code);
- errstr = "cp prefetch";
+ errstr = "cp fetch";
cp_free(&private->cp);
goto err_out;
}
--
2.17.0