libhsakmt: query/use render node fds that libdrm uses.

Query render node fds that libdrm uses for current process and
use them at Thunk if available.

v2: avoid naming conflict with amdgpu_device_get_fd from amdgpu.h

Signed-off-by: Xiaogang Chen<Xiaogang.Chen@amd.com>
Change-Id: Id7288c03730f4a4c9c3644e37ca4725fec71a471


[ROCm/ROCR-Runtime commit: ac1db60fc2]

projects/rocr-runtime/src/openclose.c

@@ -23,6 +23,11 @@
  * DEALINGS IN THE SOFTWARE.
  */
 
+/* glibc macro that enables access some nonstandard GNU/Linux extensions
+ * such as RTLD_DEFAULT used by dlsym
+ */
+#define _GNU_SOURCE
+
 #include "libhsakmt.h"
 
 #include <stdlib.h>
@@ -34,6 +39,9 @@
 #include <stdio.h>
 #include <strings.h>
 #include "fmm.h"
+#include <dlfcn.h>
+
+int (*fn_amdgpu_device_get_fd)(HsaAMDGPUDeviceHandle device_handle);
 
 static const char kfd_device_name[] = "/dev/kfd";
 static pid_t parent_pid = -1;
@@ -143,6 +151,7 @@ HSAKMT_STATUS HSAKMTAPI hsaKmtOpenKFD(void)
 	HSAKMT_STATUS result;
 	int fd = -1;
 	HsaSystemProperties sys_props;
+	char *error;
 
 	pthread_mutex_lock(&hsakmt_mutex);
 
@@ -156,6 +165,12 @@ HSAKMT_STATUS HSAKMTAPI hsaKmtOpenKFD(void)
 	if (kfd_open_count == 0) {
 		static bool atfork_installed = false;
 
+		fn_amdgpu_device_get_fd = dlsym(RTLD_DEFAULT, "amdgpu_device_get_fd");
+		if ((error = dlerror()) != NULL)
+			pr_err("amdgpu_device_get_fd is not available: %s\n", error);
+		else
+			pr_info("amdgpu_device_get_fd is available %p\n", fn_amdgpu_device_get_fd);
+
 		result = init_vars_from_env();
 		if (result != HSAKMT_STATUS_SUCCESS)
 			goto open_failed;