ROCm SMI Documentation Reorg

Change-Id: I3e4db2c50a43a51eeea4d3e06ba4811ad1859368
Signed-off-by: Charis Poag <Charis.Poag@amd.com>

docs/how-to/use-cpp.rst

@@ -0,0 +1,47 @@
+
+.. meta::
+  :description: Using ROCm SMI
+  :keywords: install, SMI, library, api, AMD, ROCm
+
+
+Using C++ in ROCm SMI
+*********************  
+
+Device indices 
+---------------
+
+Many of the functions in the library take a "device index". The device index is a number greater than or equal to 0, and less than the number of devices detected, as determined by `rsmi_num_monitor_devices()`. The index is used to distinguish the detected devices from one another. It is important to note that a device may end up with a different index after a reboot, so an index should not be relied upon to be constant over reboots.
+
+Hello ROCm SMI
+================
+
+The only required ROCm-SMI call for any program that wants to use ROCm-SMI is the `rsmi_init()` call. This call initializes some internal data structures that will be used by subsequent ROCm-SMI calls. 
+
+When ROCm-SMI is no longer being used, `rsmi_shut_down()` should be called. This provides a way to do any releasing of resources that ROCm-SMI may have held. In many cases, this may have no effect, but may be necessary in future versions of the library.
+
+A simple "Hello World" type program that displays the device ID of detected devices would look like this:
+
+.. code-block:: c
+  
+    #include <stdint.h>
+    #include "rocm_smi/rocm_smi.h"
+    int main() {
+      rsmi_status_t ret;
+      uint32_t num_devices;
+      uint16_t dev_id;
+    
+      // We will skip return code checks for this example, but it
+      // is recommended to always check this as some calls may not
+      // apply for some devices or ROCm releases
+    
+      ret = rsmi_init(0);
+      ret = rsmi_num_monitor_devices(&num_devices);
+    
+      for (int i=0; i < num_devices; ++i) {
+        ret = rsmi_dev_id_get(i, &dev_id);
+        // dev_id holds the device ID of device i, upon a
+        // successful call
+      }
+      ret = rsmi_shut_down();
+      return 0;
+    }