| Message ID | 1544623878-11248-13-git-send-email-jjherne@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | s390: vfio-ccw dasd ipl support | expand |
On Wed, 12 Dec 2018 09:11:15 -0500 "Jason J. Herne" <jjherne@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 <jjherne@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)
On 12/14/18 8:04 AM, Cornelia Huck wrote: > On Wed, 12 Dec 2018 09:11:15 -0500 > "Jason J. Herne" <jjherne@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 <jjherne@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.
On Thu, 10 Jan 2019 11:12:47 -0500 "Jason J. Herne" <jjherne@linux.ibm.com> wrote: > On 12/14/18 8:04 AM, Cornelia Huck wrote: > > On Wed, 12 Dec 2018 09:11:15 -0500 > > "Jason J. Herne" <jjherne@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 <jjherne@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. As it doesn't really hurt, I think we can defer this to later. Let's not make this patch set bigger than needed :)
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); + return do_cio(vdev->schid, ptr2u32(&ccw), CCW_FMT1); } static void vring_init(VRing *vr, VqInfo *info)
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 <jjherne@linux.ibm.com> --- pc-bios/s390-ccw/virtio.c | 21 ++------------------- 1 file changed, 2 insertions(+), 19 deletions(-)