scsi_dmaget(9f)

1scsi_dmaget(9F)          Kernel Functions for Drivers          scsi_dmaget(9F)
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NAME

6       scsi_dmaget, scsi_dmafree - SCSI dma utility routines
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SYNOPSIS

9       #include <sys/scsi/scsi.h>
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13       struct scsi_pkt *scsi_dmaget(struct scsi_pkt *pkt,
14            opaque_t dmatoken, int(*callback)(void));
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17       void scsi_dmafree(struct scsi_pkt *pkt);
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INTERFACE LEVEL

21       These   interfaces  are  obsolete.  Use  scsi_init_pkt(9F)  instead  of
22       scsi_dmaget(). Use scsi_destroy_pkt(9F) instead of scsi_dmafree().
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PARAMETERS

25       pkt         A pointer to a scsi_pkt(9S) structure.
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28       dmatoken    Pointer to an implementation dependent object.
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31       callback    Pointer to a callback function, or NULL_FUNC or SLEEP_FUNC.
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DESCRIPTION

35       The scsi_dmaget() function allocates DMA resources for an already allo‐
36       cated  SCSI  packet.  pkt is a pointer to the previously allocated SCSI
37       packet (see scsi_pktalloc(9F)).
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40       The dmatoken parameter is a  pointer  to  an  implementation  dependent
41       object  which  defines  the  length, direction, and address of the data
42       transfer associated with this SCSI packet (command). The dmatoken  must
43       be  a pointer to a buf(9S) structure. If dmatoken is NULL, no resources
44       are allocated.
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47       The callback parameter indicates  what  scsi_dmaget()  should  do  when
48       resources are not available:
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50       NULL_FUNC       Do not wait for resources. Return a NULL pointer.
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53       SLEEP_FUNC      Wait indefinitely for resources.
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56       Other Values    callback  points  to  a  function  which is called when
57                       resources may  have  become  available.  callback  must
58                       return  either 0 (indicating that it attempted to allo‐
59                       cate resources but failed to do  so  again),  in  which
60                       case it is put back on a list to be called again later,
61                       or 1 indicating either success in allocating  resources
62                       or indicating that it no longer cares for a retry.
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66       The scsi_dmafree() function frees the DMA resources associated with the
67       SCSI packet. The packet itself remains allocated.
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RETURN VALUES

70       The scsi_dmaget() function returns a pointer to a scsi_pkt on  success.
71       It returns NULL if resources are not available.
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CONTEXT

74       If  callback  is  SLEEP_FUNC, then this routine may only be called from
75       user or kernel context. Otherwise, it may be called from user,  kernel,
76       or  interrupt context. The callback function may not block or call rou‐
77       tines that block.
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80       The scsi_dmafree() function can be called from user, interrupt, or ker‐
81       nel context.
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ATTRIBUTES

84       See attributes(5) for a description of the following attributes:
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89       ┌─────────────────────────────┬─────────────────────────────┐
90       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
91       ├─────────────────────────────┼─────────────────────────────┤
92       │Stability Level              │Obsolete                     │
93       └─────────────────────────────┴─────────────────────────────┘
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NOTES

103       The scsi_dmaget() and scsi_dmafree() functions are obsolete and will be
104       discontinued  in  a  future release. These functions have been replaced
105       by, respectively, scsi_init_pkt(9F) and scsi_destroy_pkt(9F).
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109SunOS 5.11                        16 Jan 2006                  scsi_dmaget(9F)