Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
doc: add documentation for uio-hv-generic
Update UIO documentation to include basic information about
uio_hv_generic.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
authored by
Stephen Hemminger
and committed by
Jonathan Corbet
a164a8a6
5ac9baf4
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+62
Documentation/DocBook/uio-howto.tmpl
+62
Documentation/DocBook/uio-howto.tmpl
···
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<revhistory>
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<revision>
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<revnumber>0.10</revnumber>
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<date>2016-10-17</date>
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<authorinitials>sch</authorinitials>
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<revremark>Added generic hyperv driver
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</revremark>
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</revision>
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<revision>
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<revnumber>0.9</revnumber>
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<date>2009-07-16</date>
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<authorinitials>mst</authorinitials>
···
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</para>
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</sect1>
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</chapter>
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<chapter id="uio_hv_generic" xreflabel="Using Generic driver for Hyper-V VMBUS">
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<?dbhtml filename="uio_hv_generic.html"?>
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<title>Generic Hyper-V UIO driver</title>
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<para>
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The generic driver is a kernel module named uio_hv_generic.
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It supports devices on the Hyper-V VMBus similar to uio_pci_generic
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on PCI bus.
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</para>
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<sect1 id="uio_hv_generic_binding">
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<title>Making the driver recognize the device</title>
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<para>
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Since the driver does not declare any device GUID's, it will not get loaded
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automatically and will not automatically bind to any devices, you must load it
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and allocate id to the driver yourself. For example, to use the network device
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GUID:
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<programlisting>
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modprobe uio_hv_generic
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echo "f8615163-df3e-46c5-913f-f2d2f965ed0e" > /sys/bus/vmbus/drivers/uio_hv_generic/new_id
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</programlisting>
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</para>
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<para>
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If there already is a hardware specific kernel driver for the device, the
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generic driver still won't bind to it, in this case if you want to use the
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generic driver (why would you?) you'll have to manually unbind the hardware
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specific driver and bind the generic driver, like this:
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<programlisting>
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echo -n vmbus-ed963694-e847-4b2a-85af-bc9cfc11d6f3 > /sys/bus/vmbus/drivers/hv_netvsc/unbind
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echo -n vmbus-ed963694-e847-4b2a-85af-bc9cfc11d6f3 > /sys/bus/vmbus/drivers/uio_hv_generic/bind
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</programlisting>
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</para>
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<para>
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You can verify that the device has been bound to the driver
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by looking for it in sysfs, for example like the following:
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<programlisting>
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ls -l /sys/bus/vmbus/devices/vmbus-ed963694-e847-4b2a-85af-bc9cfc11d6f3/driver
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</programlisting>
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Which if successful should print
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<programlisting>
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.../vmbus-ed963694-e847-4b2a-85af-bc9cfc11d6f3/driver -> ../../../bus/vmbus/drivers/uio_hv_generic
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</programlisting>
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</para>
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</sect1>
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<sect1 id="uio_hv_generic_internals">
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<title>Things to know about uio_hv_generic</title>
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<para>
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On each interrupt, uio_hv_generic sets the Interrupt Disable bit.
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This prevents the device from generating further interrupts
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until the bit is cleared. The userspace driver should clear this
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bit before blocking and waiting for more interrupts.
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</para>
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</sect1>
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</chapter>
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<appendix id="app1">