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A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Kernel Functions for Drivers

devmap_default_access(9F)

INTERFACE LEVEL
PARAMETERS
DESCRIPTION
RETURN VALUES
CONTEXT
EXAMPLES
SEE ALSO

NAME

devmap_default_access - default driver memory access function

SYNOPSIS

#include <sys/ddi.h> #include <sys/sunddi.h> int devmap_default_access(devmap_cookie_t dhp, void *pvtp, offset_t off, size_t len, uint_t type, uint_t rw);

PARAMETERS

dhp: An opaque mapping handle that the system uses to describe the mapping.
pvtp: Driver private mapping data.
off: User offset within the logical device memory at which the access begins.
len: Length (in bytes) of the memory being accessed.
type: Type of access operation.
rw: Type of access.

devmap_default_access() is a function providing the semantics of devmap_access(9E). The drivers call devmap_default_access() to handle the mappings that do not support context switching. The drivers should call devmap_do_ctxmgt(9F) for the mappings that support context management.

devmap_default_access() can either be called from devmap_access(9E) or be used as the devmap_access(9E) entry point. The arguments dhp, pvtp, off, len, type, and rw are provided by the devmap_access(9E) entry point and must not be modified.

RETURN VALUES

0: Successful completion.
Non-zero: An error occurred.

CONTEXT

devmap_default_access() must be called from the driver's devmap_access(9E) entry point.

EXAMPLES

Example 1. Using devmap_default_access in devmap_access.

The following shows an example of using devmap_default_access() in the devmap_access(9E) entry point.

... #define OFF_DO_CTXMGT 0x40000000 #define OFF_NORMAL 0x40100000 #define CTXMGT_SIZE 0x100000 #define NORMAL_SIZE 0x100000 /* * Driver devmap_contextmgt(9E) callback function. */ static int xx_context_mgt(devmap_cookie_t dhp, void *pvtp, offset_t offset, size_t length, uint_t type, uint_t rw) { ...... /* * see devmap_contextmgt(9E) for an example */ } /* * Driver devmap_access(9E) entry point */ static int xxdevmap_access(devmap_cookie_t dhp, void *pvtp, offset_t off, size_t len, uint_t type, uint_t rw) { offset_t diff; int err; /* * check if off is within the range that supports * context management. */ if ((diff = off - OFF_DO_CTXMG) >= 0 && diff < CTXMGT_SIZE) { /* * calculates the length for context switching */ if ((len + off) > (OFF_DO_CTXMGT + CTXMGT_SIZE)) return (-1); /* * perform context switching */ err = devmap_do_ctxmgt(dhp, pvtp, off, len, type, rw, xx_context_mgt); /* * check if off is within the range that does normal * memory mapping. */ } else if ((diff = off - OFF_NORMAL) >= 0 && diff < NORMAL_SIZE) { if ((len + off) > (OFF_NORMAL + NORMAL_SIZE)) return (-1); err = devmap_default_access(dhp, pvtp, off, len, type, rw); } else return (-1); return (err); }