sdi_xicmd(D3sdi)

sdi_xicmd -- perform requested operation immediately

Synopsis

   #include <sys/types.h>
   #include <sys/sdi.h>
   #include <sys/ddi.h>
   
   int sdi_xicmd(int hbaflag, struct sb *pt,
                 int sleepflag);

Description

sdi_xicmd( ) sends an immediate sb(D4sdi) structure to a device. Immediate means that this function bypasses queued scb requests and immediately accesses the device to perform the requested operation.

Arguments

hbaflag: Initialize to HBA_EXT_ADDRESS for drivers that understand extended SCSI addressing, or to 0 for drivers that only understand conventional SCSI addressing.
pt: Pointer to the sb(D4sdi) command block structure; the sb_type member of the sb structure must be set to either SFB_TYPE or SCB_TYPE.
sleepflag: Indicates whether the allocation may block or not. Valid values are KM_SLEEP or KM_NOSLEEP.

Return values

A return code of SDI_RET_OK indicates that the request is in progress and the target driver interrupt routine will be called after command completion. A return code of SDI_RET_ERR indicates that the type field is invalid. After a logical unit queue is resumed, all outstanding immediate control and function blocks are processed, followed by the next normal command.

Usage

sdi_xicmd( ) is typically used during error handling.

In contrast to an operation using an sfb(D4sdi), operations using an scb send the job to the requested logical unit.

Coming in at immediate-priority, operations using an sfb are executed in the order submitted and take priority over scb operations. Only one instance of each immediate command type (SFB_TYPE or ISCB_TYPE) may be outstanding to a particular logical unit.

The command block must be allocated from the host adapter pool of command blocks, and the addresses translated using the sdi_xtranslate(D3sdi) function.

Context and synchronization

If flag is set to KM_NOSLEEP, non-blockable, initialization, or interrupt context.

If flag is set to KM_SLEEP, user context.

Hardware applicability

All

Version applicability

sdi: 4 target drivers

Differences between versions

SDI versions prior to SDI version 4 use the sdi_icmd( ) function, which cannot be used with extended SCSI addresses, rather than sdi_icmd( ). The syntax is:

   int sdi_icmd(struct sb *pt, int flag);

sdi_icmd( ) requests are translated with the sdi_translate(D3sdi) function rather than sdi_xtranslate( ).

References

sb(D4sdi), scb(D4sdi), sdi_xtranslate(D3sdi), sfb(D4sdi)

``Extended SCSI addressing scheme'' in HDK Technical Reference

Examples

The following example shows how an sb is re-sent using sdi_xicmd( ) when the sc_comp_code(D5sdi) is set to SDI_RETRY to indicate that a retry is requested. diskint( ) is an example of a disk target driver interrupt routine.

      void
      diskint(sb_ptr)
      struct sb *sb_ptr;
      {
          ...
   
          /* Check the completion code of the SCB to see if the
           * command needs to be retried.
           */
          if (sb_ptr->SCB.sc_comp_code & SDI_RETRY )
          {       
              /* Retry the command request using sdi_xicmd */
                 if (sdi_xicmd(HBA_EXT_ADDRESS, sb_ptr, flag) != SDI_RET_OK)
              {
                  /* If the return value of sdi_xicmd is not OK,
                   * print an error message.
                   */
                   cmn_err(CE_WARN, "DISK: Bad SB type to SDI.");
              }
          return;
      }
      ...