Function hipDeviceEnablePeerAccess 

pub unsafe extern "C" fn hipDeviceEnablePeerAccess(
    peerDeviceId: c_int,
    flags: c_uint,
) -> hipError_t

@brief Enables direct access to memory allocations on a peer device.

When this API is successful, all memory allocations on peer device will be mapped into the address space of the current device. In addition, any future memory allocation on the peer device will remain accessible from the current device, until the access is disabled using hipDeviceDisablePeerAccess or device is reset using hipDeviceReset.

@param [in] peerDeviceId - Peer device to enable direct access to from the current device @param [in] flags - Reserved for future use, must be zero

@returns #hipSuccess, #hipErrorInvalidDevice, #hipErrorInvalidValue, @returns #hipErrorPeerAccessAlreadyEnabled if peer access is already enabled for this device.