On 12/14/18 8:04 AM, Cornelia Huck wrote:
On Wed, 12 Dec 2018 09:11:15 -0500
"Jason J. Herne" <jjhe...@linux.ibm.com> wrote:
Now that we have a Channel I/O library let's modify virtio boot code to
make use of it for running channel programs.
Signed-off-by: Jason J. Herne <jjhe...@linux.ibm.com>
---
pc-bios/s390-ccw/virtio.c | 21 ++-------------------
1 file changed, 2 insertions(+), 19 deletions(-)
diff --git a/pc-bios/s390-ccw/virtio.c b/pc-bios/s390-ccw/virtio.c
index aa9da72..5fb49e2 100644
--- a/pc-bios/s390-ccw/virtio.c
+++ b/pc-bios/s390-ccw/virtio.c
@@ -92,30 +92,13 @@ int drain_irqs(SubChannelId schid)
static int run_ccw(VDev *vdev, int cmd, void *ptr, int len)
{
Ccw1 ccw = {};
- CmdOrb orb = {};
- int r;
-
- enable_subchannel(vdev->schid);
-
- /* start subchannel command */
- orb.fmt = 1;
- orb.cpa = (u32)(long)&ccw;
- orb.lpm = 0x80;
ccw.cmd_code = cmd;
ccw.cda = (long)ptr;
ccw.count = len;
- r = ssch(vdev->schid, &orb);
- /*
- * XXX Wait until device is done processing the CCW. For now we can
- * assume that a simple tsch will have finished the CCW processing,
- * but the architecture allows for asynchronous operation
- */
- if (!r) {
- r = drain_irqs(vdev->schid);
- }
- return r;
+ enable_subchannel(vdev->schid);
Preexisting, but I'm wondering why we enable the subchannel here and
not just once?
+ return do_cio(vdev->schid, ptr2u32(&ccw), CCW_FMT1);
}
static void vring_init(VRing *vr, VqInfo *info)
Good question. It seems to be needed for the net-boot path. Here is the chain:
netmain.c : main()
netmain,c : net_init()
virtio-net.c : virtio_net_init()
virtio.c : virtio_setup_ccw()
virtio.c : run_ccw()
In this case the subchannel would not already be enabled. I suppose I *could* change it,
but at this point I'm trying to limit how much more code I'm touching :). This patch set
already touches a bit more code than I anticipated. Let me know what your thoughts are.
--
-- Jason J. Herne (jjhe...@linux.ibm.com)
