READ_REGISTER_ULONG64 function (wdm.h)

The READ_REGISTER_ULONG64 routine dereferences the supplied pointer, inserts a memory barrier, and reads a ULONG64 value from the specified register address.

Syntax

ULONG64 READ_REGISTER_ULONG64(
  [in] volatile ULONG64 *Register
);

Parameters

[in] Register

Pointer to the register address, which must be a mapped range in memory space.

Return value

READ_REGISTER_ULONG64 returns the ULONG64 value that is read from the specified register address.

Remarks

This routine inserts a memory barrier into your code. This barrier guarantees that every operation that appears in the source code before the call to this routine will complete before any operation that appears after the call.

For more info about memory barriers, see KeMemoryBarrier.

Callers of the READ_REGISTER_ULONG64 macro can be running at any IRQL, assuming the Register address is resident, mapped device memory.

Requirements