added graceful fallback when FASTRPC_GET_URI call fails

Author: l3utterfly

ggml/src/ggml-hexagon/ggml-hexagon.cpp

@@ -9,6 +9,7 @@
 #include <chrono>
 #include <mutex>
 #include <string>
+#include <dlfcn.h>
 
 #ifdef _WIN32
 #    include <sal.h>
@@ -51,6 +52,15 @@ static int    opt_experimental = 0;
 static int opt_opmask = HTP_OPMASK_QUEUE | HTP_OPMASK_QUANTIZE | HTP_OPMASK_COMPUTE;
 static int opt_opsync = 0;  // synchronous ops
 
+// function signature defined in rpcmem.h
+using pfn_rpc_mem_alloc                         = void *(*)(int, uint32_t, size_t);
+
+// Dynamic pointers to functions in lib[cdsp]rpc.so, used for backward compatibility with older SoCs
+// library open happens in the constructor of ggml_hexagon_registry, and closed in the destructor
+
+// dynamic pointer to function rpcmem_alloc or rpcmem_alloc2 at runtime
+static pfn_rpc_mem_alloc _pfn_rpc_mem_alloc = nullptr;
+
 #define HEX_VERBOSE(...) \
     if (opt_verbose) GGML_LOG_DEBUG(__VA_ARGS__)
 
@@ -367,7 +377,9 @@ struct ggml_backend_hexagon_buffer_context {
     ggml_backend_hexagon_buffer_context(ggml_hexagon_session * sess, size_t size, bool repack) {
         size += 4 * 1024;  // extra page for padding
 
-        this->base = (uint8_t *) rpcmem_alloc(RPCMEM_HEAP_ID_SYSTEM, RPCMEM_DEFAULT_FLAGS | RPCMEM_HEAP_NOREG, size);
+        GGML_ASSERT(_pfn_rpc_mem_alloc != nullptr);
+
+        this->base = (uint8_t *) _pfn_rpc_mem_alloc(RPCMEM_HEAP_ID_SYSTEM, RPCMEM_DEFAULT_FLAGS | RPCMEM_HEAP_NOREG, size);
         if (!this->base) {
             GGML_LOG_ERROR("ggml-hex: %s failed to allocate buffer : size %zu\n", sess->name.c_str(), size);
             throw std::runtime_error("ggml-hex: rpcmem_alloc failed (see log for details)");
@@ -1683,7 +1695,7 @@ void ggml_hexagon_session::allocate(int dev_id) noexcept(false) {
     sprintf(htp_uri, "file:///libggml-htp-v%u.so?htp_iface_skel_handle_invoke&_modver=1.0", opt_arch);
 
     char session_uri[256];
-    if(false) {
+    {
         struct remote_rpc_get_uri u;
         u.session_id      = this->session_id;
         u.domain_name     = const_cast<char *>(CDSP_DOMAIN_NAME);
@@ -1695,13 +1707,13 @@ void ggml_hexagon_session::allocate(int dev_id) noexcept(false) {
 
         int err = remote_session_control(FASTRPC_GET_URI, (void *) &u, sizeof(u));
         if (err != AEE_SUCCESS) {
-            GGML_LOG_ERROR("ggml-hex: failed to get URI for session %d : error 0x%x\n", dev_id, err);
-            throw std::runtime_error("ggml-hex: remote_session_control(get-uri) failed (see log for details)");
-        }
-    } else {
-        int htp_URI_domain_len = strlen(htp_uri) + MAX_DOMAIN_NAMELEN;
+            // fallback to single session uris
+            int htp_URI_domain_len = strlen(htp_uri) + MAX_DOMAIN_NAMELEN;
+
+            snprintf(session_uri, htp_URI_domain_len, "%s%s", htp_uri, my_domain->uri);
 
-        snprintf(session_uri, htp_URI_domain_len, "%s%s", htp_uri, my_domain->uri);
+            GGML_LOG_WARN("ggml-hex: failed to get URI for session %d : error 0x%x. Falling back to single session URI: %s\n", dev_id, err, session_uri);
+        }
     }
 
     // Enable Unsigned PD
@@ -3659,6 +3671,9 @@ struct ggml_hexagon_registry {
     ~ggml_hexagon_registry();
 
     ggml_backend_device devices[GGML_HEXAGON_MAX_SESSIONS];
+
+    // dynamic handles
+    void * _rpc_lib_handle      = nullptr;
 };
 
 ggml_hexagon_registry::ggml_hexagon_registry(ggml_backend_reg_t reg) {
@@ -3685,6 +3700,30 @@ ggml_hexagon_registry::ggml_hexagon_registry(ggml_backend_reg_t reg) {
             devices[i].context = nullptr;
         }
     }
+
+    // obtain handle to dsp library
+    _rpc_lib_handle = dlopen("libcdsprpc.so", RTLD_NOW | RTLD_LOCAL);
+    if (nullptr == _rpc_lib_handle) {
+        GGML_LOG_ERROR("ggml-hex: failed to load rpc lib: %s", dlerror());
+        throw std::runtime_error("failed to load rpc lib");
+    }
+
+    // attempt to load rpc_memalloc2 first
+    _pfn_rpc_mem_alloc  = reinterpret_cast<pfn_rpc_mem_alloc>(dlsym(_rpc_lib_handle,"rpcmem_alloc2"));
+
+    // fallback to rpc_memalloc
+    if(_pfn_rpc_mem_alloc == nullptr) {
+        _pfn_rpc_mem_alloc  = reinterpret_cast<pfn_rpc_mem_alloc>(dlsym(_rpc_lib_handle,"rpcmem_alloc"));
+
+        if(_pfn_rpc_mem_alloc == nullptr) {
+            GGML_LOG_ERROR("ggml-hex: failed to get rpcmem_alloc function address: %s", dlerror());
+            throw std::runtime_error("failed to get rpcmem_alloc function address");
+        } else {
+            GGML_LOG_INFO("ggml-hex: using rpcmem_alloc\n");
+        }
+    } else {
+        GGML_LOG_INFO("ggml-hex: using rpcmem_alloc2\n");
+    }
 }
 
 ggml_hexagon_registry::~ggml_hexagon_registry() {
@@ -3695,6 +3734,8 @@ ggml_hexagon_registry::~ggml_hexagon_registry() {
         auto sess = static_cast<ggml_hexagon_session *>(devices[i].context);
         delete sess;
     }
+
+    if(_rpc_lib_handle) dlclose(_rpc_lib_handle);
 }
 
 static const char * ggml_backend_hexagon_reg_get_name(ggml_backend_reg_t reg) {