Style update for SDMA enable flag.

Updated to match xnack flag's style.

Change-Id: I6115c0b53660d789e698de1606a9388ae1789866

runtime/hsa-runtime/core/runtime/amd_gpu_agent.cpp

@@ -565,11 +565,11 @@ void GpuAgent::InitDma() {
 
   // Decide which engine to use for blits.
   auto blit_lambda = [this](bool use_xgmi, lazy_ptr<core::Queue>& queue) {
-    const std::string& sdma_override = core::Runtime::runtime_singleton_->flag().enable_sdma();
+    Flag::SDMA_OVERRIDE sdma_override = core::Runtime::runtime_singleton_->flag().enable_sdma();
 
     // User SDMA queues are unstable on gfx8.
     bool use_sdma = ((isa_->GetMajorVersion() != 8));
-    if (sdma_override.size() != 0) use_sdma = (sdma_override == "1");
+    if (sdma_override != Flag::SDMA_DEFAULT) use_sdma = (sdma_override == Flag::SDMA_ENABLE);
 
     if (use_sdma && (HSA_PROFILE_BASE == profile_)) {
       auto ret = CreateBlitSdma(use_xgmi);

runtime/hsa-runtime/core/util/flag.h

@@ -54,6 +54,8 @@ namespace rocr {
 
 class Flag {
  public:
+  enum SDMA_OVERRIDE { SDMA_DISABLE, SDMA_ENABLE, SDMA_DEFAULT };
+
   explicit Flag() { Refresh(); }
 
   virtual ~Flag() {}
@@ -71,7 +73,8 @@ class Flag {
     var = os::GetEnvVar("HSA_ENABLE_INTERRUPT");
     enable_interrupt_ = (var == "0") ? false : true;
 
-    enable_sdma_ = os::GetEnvVar("HSA_ENABLE_SDMA");
+    var = os::GetEnvVar("HSA_ENABLE_SDMA");
+    enable_sdma_ = (var == "0") ? SDMA_DISABLE : ((var == "1") ? SDMA_ENABLE : SDMA_DEFAULT);
 
     visible_gpus_ = os::GetEnvVar("ROCR_VISIBLE_DEVICES");
     filter_visible_gpus_ = os::IsEnvVarSet("ROCR_VISIBLE_DEVICES");
@@ -152,7 +155,7 @@ class Flag {
 
   bool no_scratch_thread_limiter() const { return no_scratch_thread_limit_; }
 
-  std::string enable_sdma() const { return enable_sdma_; }
+  SDMA_OVERRIDE enable_sdma() const { return enable_sdma_; }
 
   std::string visible_gpus() const { return visible_gpus_; }
 
@@ -187,7 +190,7 @@ class Flag {
   bool disable_image_;
   bool loader_enable_mmap_uri_;
 
-  std::string enable_sdma_;
+  SDMA_OVERRIDE enable_sdma_;
 
   bool filter_visible_gpus_;
   std::string visible_gpus_;