MFSH_UNPGYSTOVIRT - Mark a completion of use of virtual adress

Purpose

Release the selector allocated previously by calling MFSH_PHYSTOVIRT.

Calling Sequence

int far pascal MFSH_UNPHYSTOVIRT(usSel) unsigned short usSel;

Where

usSel contains the selector to released.

Returns

If no error is detected, a zero error code is returned. If an error is detected, the following error code is returned:

ERROR_PROTECTION_VIOLATION – the supplied selector is invalid.

Remarks

This helper is for use by a mini-FSD with an imbedded device driver. It is the same as the standard device driver UNPHYSTOVIRT helper.

A caller must issue a corresponding UNPHYSTOVIRT after calling PHYSTOVIRT, before returning to its caller or using any other helpers.