xref: /illumos-gate/usr/src/man/man9e/mr_rget.9e (revision d48be21240dfd051b689384ce2b23479d757f2d8)
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12.\" Copyright (c) 2017, Joyent, Inc.
13.\" Copyright 2022 Oxide Compuer Company
14.\"
15.Dd July 2, 2022
16.Dt MR_RGET 9E
17.Os
18.Sh NAME
19.Nm mr_rget
20.Nd fill in ring information
21.Sh SYNOPSIS
22.In sys/mac_provider.h
23.Ft void
24.Fo prefix_fill_ring_info
25.Fa "void *driver"
26.Fa "mac_ring_type_t rtype"
27.Fa "const int group_index"
28.Fa "const int ring_index"
29.Fa "mac_ring_info_t *infop"
30.Fa "mac_ring_handle_t rh"
31.Fc
32.Sh INTERFACE LEVEL
33.Sy Uncommitted -
34This interface is still evolving.
35API and ABI stability is not guaranteed.
36.Sh PARAMETERS
37.Bl -tag -width Fa
38.It Fa driver
39A pointer to the driver's private data that was passed in via the
40.Fa m_pdata
41member of the
42.Xr mac_register 9S
43structure to the
44.Xr mac_register 9F
45function.
46.It Fa group_index
47An integer value indicating the group that this ring belongs to.
48Groups are numbered starting from zero.
49.It Fa rtype
50A value indicating the type of ring.
51Valid values include:
52.Bl -tag -width Dv
53.It Dv MAC_RING_TYPE_RX
54The ring is a receive ring.
55.It Dv MAC_RING_TYPE_TX
56The ring is a transmit ring.
57.El
58.It Fa ring_index
59An integer indicating the index of the ring inside of the group.
60Ring indexes are numbered starting from zero.
61Each group has its own set of ring indexes.
62.It Fa infop
63A pointer to an instance of a
64.Xr mac_ring_info 9S
65structure.
66.It Fa rh
67An opaque pointer to a ring handle that can be used to identify this
68ring.
69.El
70.Sh DESCRIPTION
71The
72.Fn mr_rget
73entry point provides a means for the device driver to fill in
74information about a ring.
75The driver must fill in information into the
76.Fa infop
77argument.
78For the list of fields and an explanation of how to fill them in, please
79see
80.Xr mac_ring_info 9S .
81.Pp
82The
83.Fa rtype
84argument describes whether this is a receive ring or transmit ring
85identified by a value of
86.Dv MAC_RING_TYPE_RX
87or
88.Dv MAC_RING_TYPE_TX
89respectively.
90The ring information that is filled in varies between transmit and
91receive rings.
92If separate entry points were not specified in the
93.Xr mac_capab_rings 9E
94structure, then the driver
95must ensure that it checks this value.
96.Pp
97The
98.Fa group_index
99and
100.Fa ring_index
101arguments are used to uniquely identify a ring.
102The number of groups that a driver supports is based on the values
103present in the
104.Fa mr_gnum
105member of the
106.Vt mac_capbab_rings_t
107structure which is described in
108.Xr mac_capab_rings 9E .
109The group index ranges from zero to the specified number of groups minus
110one.
111The number of rings in the group is determined based on the values
112specified in
113.Xr mac_group_info 9S
114structure that is filled in during the
115.Xr mr_gget 9E
116entry point.
117The ring numbering for each group is independent and always starts at
118zero.
119Based on the combination of group and ring index, the driver should be
120able to map that to a unique ring.
121.Pp
122After filling out the ring structure in
123.Fa infop ,
124the driver should make sure to store the ring handle in
125.Fa rh
126for future use.
127This is required for callbacks such as
128.Xr mac_rx_ring 9F
129or
130.Xr mac_tx_ring_update 9F .
131.Sh CONTEXT
132The
133.Fn mr_rget
134entry point will be called in response to a driver calling the
135.Xr mac_register 9F
136function and the driver has acknowledged that it supports the
137.Dv MAC_CAPAB_RINGS
138capability.
139This will be called after a call to the driver's
140.Xr mr_gget 9E
141entry point.
142.Sh SEE ALSO
143.Xr mac 9E ,
144.Xr mac_capab_rings 9E ,
145.Xr mr_gget 9E ,
146.Xr mac_register 9F ,
147.Xr mac_rx_ring 9F ,
148.Xr mac_tx_ring_update 9F ,
149.Xr mac_group_info 9S ,
150.Xr mac_register 9S ,
151.Xr mac_ring_info 9S
152