1scsi_ifgetcap(9F) Kernel Functions for Drivers scsi_ifgetcap(9F)
2
6 scsi_ifgetcap, scsi_ifsetcap - get/set SCSI transport capability
7
9 #include <sys/scsi/scsi.h>
10 int scsi_ifgetcap(struct scsi_address *ap, char *cap, int whom);
14 int scsi_ifsetcap(struct scsi_address *ap, char *cap, int value,
17 int whom);
18
21 Solaris DDI specific (Solaris DDI).
22
24 ap Pointer to the scsi_address structure.
25 cap Pointer to the string capability identifier.
28 value Defines the new state of the capability.
31 whom Determines if all targets or only the specified target is
34 affected.
35
38 The scsi_ifsetcap() function is used by target drivers to set the capa‐
39 bilities of the host adapter driver. The cap pointer is a name-value
40 pair identified by a null-terminated character string and the integer
41 value of the cap. The current value of the capability can be retrieved
42 with the scsi_ifgetcap() function. If the whom value is 0, all target
43 drivers are affected. Otherwise, the scsi_address structure pointed to
44 by ap is the only target that is affected.
45 The driver should confirm that scsi_ifsetcap() and scsi_ifsetcap()
48 functions are called with a cap that points to a capability which is
49 supported by the device.
50 The following capabilities have been defined:
53 dma-max Maximum dma transfer size that is supported by
55 the host adapter.
56 dma-max-arch Maximum dma transfer size that is supported by
59 system. Takes the host adapter and system
60 architecture into account. This is useful for
61 target drivers which do not support partial
62 DMAs on systems which do not have an IOMMU. In
63 this case, the DMA can also be limited by the
64 host adapters "scatter/gather" list con‐
65 straints.
66 The "dma-max-arch" capability can not be set.
68 It is implemented with this command and does
69 not rely on a tran_getcap(9E) response from the
70 HBA.
71 msg-out Message out capability that is supported by the
74 host adapter: 0 disables, 1 enables.
75 disconnect Disconnect capability that is supported by the
78 host adapter: 0 disables, 1 enables.
79 synchronous Synchronous data transfer capability that is
82 supported by the host adapter: 0 disables, 1
83 enables.
84 wide-xfer Wide transfer capability that is supported by
87 the host adapter: 0 disables, 1 enables.
88 parity Parity checking capability that is supported by
91 host adapter: 0 disables, 1 enables.
92 initiator-id Host bus address that is returned.
95 untagged-qing Host adapter capability that supports internal
98 queueing of commands without tagged queueing: 0
99 disables, 1 enables.
100 tagged-qing Host adapter capability that supports queuing:
103 0 disables, 1 enables.
104 auto-rqsense Host adapter capability that supports auto
107 request sense on check conditions: 0 disables,
108 1 enables.
109 sector-size Capability that is set by the target driver to
112 inform the HBA of the granularity, in bytes, of
113 the DMA breakup. The HBA DMA limit structure is
114 set to reflect the byte total of this setting.
115 See ddi_dma_lim_sparc(9S) or
116 ddi_dma_lim_x86(9S). The sector-size should be
117 set to the size of the physical disk sector.
118 The capability defaults to 512 bytes.
119 total-sectors Capability that is set by the target driver to
122 inform the HBA of the total number of sectors
123 on the device returned by the SCSI get capacity
124 command. This capability must be set before the
125 target driver ``gets'' the geometry capability.
126 geometry Capability that returns the HBA geometry of a
129 target disk. The target driver sets the total-
130 sectors capability before ``getting'' the geom‐
131 etry capability. The geometry is returned as a
132 32-bit value. The upper 16 bits represent the
133 number of heads per cylinder. The lower 16 bits
134 represent the number of sectors per track. The
135 geometry capability cannot be ``set''.
136 If geometry is not relevant or appropriate for
138 the target disk, scsi_ifgetcap() can return -1
139 to indicate that the geometry is not defined.
140 For example, if the HBA BIOS supports Logical
141 Block Addressing for the target disk,
142 scsi_ifgetcap() returns -1. Attempts to
143 retreive the "virtual geometry" from the target
144 driver, such as the DKIOCG_VIRTGEOM ioctl, will
145 fail. See dkio(7I) for more information about
146 DKIOCG_VIRTGEOM.
147 reset-notification Host adapter capability that supports bus reset
150 notification: 0 disables, 1 enables. See
151 scsi_reset_notify(9F).
152 linked-cmds Host adapter capability that supports linked
155 commands: 0 disables, 1 enables.
156 qfull-retries Capability that enables or disables QUEUE FULL
159 handling. If 0, the HBA will not retry a com‐
160 mand when a QUEUE FULL status is returned. If
161 the value is greater than 0, the HBA driver
162 retries the command a specified number of times
163 at an interval determined by the qfull-retry-
164 interval. The range for qfull-retries is 0-255.
165 qfull-retry-interval Capability that sets the retry interval in mil‐
168 liseconds (ms) for commands completed with a
169 QUEUE FULL status. The range for qfull-retry-
170 intervals is 0-1000 ms.
171 lun-reset Capability that is created with a value of zero
174 by HBA drivers that support the RESET_LUN flag
175 in the tran_reset(9E) function. If it exists,
176 the lun-reset value can be set to 1 by target
177 drivers to allow the use of LOGICAL UNIT RESET
178 on a specific target instance. If lun-reset
179 does not exist or has a value of zero,
180 scsi_reset(9F) is prevented from passing the
181 RESET_LUN flag to tran_reset() function of the
182 HBA driver. If lun-reset exists and has a value
183 of 1, the tran_reset() function of the HBA
184 driver can be called with the RESET_LUN flag.
185 interconnect-type Capability held in the tran_interconnect_type
188 element of struct scsi_hba_tran that indicates
189 the HBA transport interconnect type . The inte‐
190 ger value of the interconnect type of the
191 transport is defined in the services.h header
192 file.
193 max-cdb-length Host adapter capability of the maximum sup‐
196 ported CDB (Command Descriptor Block) length.
197 The target driver asks for the capability at
198 attach time. If the HBA driver supports the
199 capability, the maximum length of the CDB is
200 returned in bytes. The target driver can then
201 use that value to determine which CDB is used
202 for the HBA.
203 If the HBA driver does not support the max-cdb-
205 length capability, the default value of the
206 target driver is used for the CDB determina‐
207 tion.
208
211 The scsi_ifsetcap() function returns:
212 1 If the capability was successfully set to the new value.
214 0 If the capability is not variable.
217 −1 If the capability was not defined, or setting the capability
220 to a new value failed.
221 The scsi_ifgetcap() function returns the current value of a capability,
225 or:
226 −1 If the capability was not defined.
228
231 Example 1 Using scsi_ifgetcap()
232 if (scsi_ifgetcap(&sd->sd_address, "auto-rqsense", 1) == 1) {
234 un->un_arq_enabled = 1;
235 } else {
236 un->un_arq_enabled =
237 ((scsi_ifsetcap(&sd->sd_address, "auto-rqsense", 1, 1) == 1) ?
238 1 : 0);
239 }
240 if (scsi_ifsetcap(&devp->sd_address, "tagged-qing", 1, 1) == 1) {
242 un->un_dp->options |= SD_QUEUEING;
243 un->un_throttle = MAX_THROTTLE;
244 } else if (scsi_ifgetcap(&devp->sd_address, "untagged-qing", 0) == 1) {
245 un->un_dp->options |= SD_QUEUEING;
246 un->un_throttle = 3;
247 } else {
248 un->un_dp->options &= ~SD_QUEUEING;
249 un->un_throttle = 1;
250 }
251
254 These functions can be called from user, interrupt, or kernel context.
255
257 See attributes(5) for descriptions of the following attributes:
258 ┌─────────────────────────────┬─────────────────────────────┐
263 │ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
264 ├─────────────────────────────┼─────────────────────────────┤
265 │Interface Stability │Committed │
266 └─────────────────────────────┴─────────────────────────────┘
267
269 tran_reset(9E), scsi_hba_lookup_capstr(9F), scsi_reset(9F),
270 scsi_reset_notify(9F), ddi_dma_lim_sparc(9S), ddi_dma_lim_x86(9S),
271 scsi_address(9S), scsi_arq_status(9S)
272 Writing Device Drivers
275SunOS 5.11 16 Oct 2007 scsi_ifgetcap(9F)