devmap_unmap(9e)

1devmap_unmap(9E)              Driver Entry Points             devmap_unmap(9E)
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NAME

6       devmap_unmap - device mapping unmap entry point
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SYNOPSIS

9       #include <sys/ddi.h>
10       #include <sys/sunddi.h>
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14       void prefixdevmap_unmap(devmap_cookie_t dhp, void *pvtp,
15            offset_t off, size_tlen, devmap_cookie_t new_dhp1,
16            void **new_pvtp1, devmap_cookie_tnew_dhp2, void **new_pvtp2);
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18

INTERFACE LEVEL

20       Solaris DDI specific (Solaris DDI).
21

ARGUMENTS

23       dhp           An opaque mapping handle that the system uses to describe
24                     the mapping.
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27       pvtp          Driver private mapping data.
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30       off           User offset within the logical device memory at which the
31                     unmapping begins.
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34       len           Length (in bytes) of the memory being unmapped.
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37       new_dhp1      The  opaque  mapping  handle  that  the  system  uses  to
38                     describe the new region that ends at (off - 1) . new_dhp1
39                     may be  NULL.
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42       new_pvtp1     A  pointer  to be filled in by the driver with the driver
43                     private mapping data for the new region that ends at (off
44                     - 1); ignored if new_dhp1 is  NULL.
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47       new_dhp2      The  opaque  mapping  handle  that  the  system  uses  to
48                     describe the new region that  begins  at  (off   +  len);
49                     new_dhp2 may be  NULL.
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52       new_pvtp2     A  pointer  to be filled in by the driver with the driver
53                     private mapping data for the new region  that  begins  at
54                     (off + len);  ignored if  new_dhp2 is  NULL.
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56

DESCRIPTION

58       devmap_unmap()  is  called  when  the system removes the mapping in the
59       range [ off, off + len ], such as in the  munmap(2) or  exit(2)  system
60       calls. Device drivers use devmap_unmap() to free up the resources allo‐
61       cated in devmap_map(9E).
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64       dhp is the mapping handle that uniquely identifies the  mapping.    The
65       driver  stores  the  mapping  attributes  in the driver's private data,
66       pvtp, when the mapping is created.  See devmap_map(9E) for details.
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69       off and len define the range to be  affected  by  devmap_unmap().  This
70       range is within the boundary of the mapping described by dhp.
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73       If  the  range [ off, off + len ] covers the entire mapping, the system
74       passes  NULL to  new_dhp1, new_pvtp1, new_dhp2, and new_pvtp2. The sys‐
75       tem  expects  device  drivers  to free all resources allocated for this
76       mapping.
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79       If off is at the beginning of the mapping and  len does not  cover  the
80       entire mapping, the system sets  NULL to new_dhp1 and to new_pvtp1. The
81       system expects the drivers to allocate new driver private  data for the
82       region  that  starts at off + len and to set *new_pvtp2 to point to it.
83       new_dhp2 is the mapping handle of the newly mapped object.
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86       If off is not at the beginning of the mapping, but off + len is at  the
87       end  of  the mapping the system passes  NULL to new_dhp2 and new_pvtp2.
88       The system then expects the drivers to allocate new driver private data
89       for  the  region that begins at the beginning of the mapping (for exam‐
90       ple, stored in pvtp) and to set *new_pvtp1 to point to it. new_dhp1  is
91       the mapping handle of the newly mapped object.
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94       The  drivers  should  free up the driver private data, pvtp, previously
95       allocated in devmap_map(9E) before returning to the system.
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EXAMPLES

98       Example 1 devmap_unmap() implementation
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100         static void
101         xxdevmap_unmap(devmap_cookie_t dhp, void *pvtp, offset_t off,
102             size_t len, devmap_cookie_t new_dhp1, void **new_pvtp1,
103             devmap_cookie_t new_dhp2, void **new_pvtp2)
104         {
105             struct xxpvtdata *ptmp;
106             struct xxpvtdata *p = (struct xxpvtdata *)pvtp;
107             struct xx_softc  *softc = p->softc;
108             mutex_enter(&softc->mutex);
109             /*
110              * If new_dhp1 is not NULL, create a new driver private data
111              * for the region from the beginning of old mapping to off.
112              */
113             if (new_dhp1 != NULL) {
114                 ptmp = kmem_zalloc(sizeof (struct xxpvtdata), KM_SLEEP);
115                 ptmp->dhp = new_dhp1;
116                 ptmp->off = pvtp->off;
117                 ptmp->len = off - pvtp->off;
118                 *new_pvtp1 = ptmp;
119             }
120
121             /*
122              * If new_dhp2 is not NULL, create a new driver private data
123              * for the region from off+len to the end of the old mapping.
124              */
125             if (new_dhp2 != NULL) {
126                 ptmp = kmem_zalloc(sizeof (struct xxpvtdata), KM_SLEEP);
127                 ptmp->off = off + len;
128                 ptmp->len = pvpt->len - (off + len - pvtp->off);
129                 ptmp->dhp = new_dhp2;
130                 *new_pvtp2 = ptmp;
131             }
132
133             /* Destroy the driver private data - Device dependent */
134             ...
135             kmem_free(pvtp, sizeof (struct xxpvtdata));
136             mutex_exit(&softc->mutex);
137         }
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139

NAME

SYNOPSIS

INTERFACE LEVEL

ARGUMENTS

DESCRIPTION

EXAMPLES

SEE ALSO