Implicit mapped memory access is there any way to access device mem in implicitly?

The graphic card is GT 9500, although the canMapHostMemory field of deviceProperty is 0,
but the mapped memory could be enabled by invoking cudaSetDeviceFlags with cudaDeviceMapHost.

I have needs to provide pointers which can access host memory in host code, and it could be passed to kernel/device function to access the original device memory.

Is there any way to have such a mapped pointer?
the problem is that we still have to pass the device pointer to device function. not the host pointer.

My opinion is to redirect the address from device pointer to host memory, so that we can access it as
access the host memory.

I hope I could have such code

void*
myAlloc(int size){
void* pHost;
void* pDevice;
cudaHostAlloc(&pHost,size,cudaHostAllocMapped|cudaHostAllocWriteCombine
d);
getRedirectedDevicePointer( &pDevice,pHost, size ); /* specify the start address and range */
return pDevice;
}

void some_function(){
int* p = (int*)myAlloc(1024);
for(int i=0; i<1024; ++i){
p[ i ] = rand(); /* implicitly access, which could redirect to access the original host memroy /
}
kernel_function<<<1,1,0>>>§; /
pass for device to access its mapped memory */
cudaThreadSynchronize();
for(int i=0; i<1024; ++i){
printf("%d ",p[ i ]);
}
}

Sorry, but you will have to add a cudamemcpy() to copy data back and forth your graphic card memory.
Anyway it will be faster to have a full copy, back and forth of huge dataset, than to poll it one DWORD at a time via PCI-express, due to it’s latency!
(probably on the order of 100X faster!)