libhsakmt: Don't close kfd_fd

When hsa is closed, it would close open fds for /dev/kfd but
not for /dev/dri/renderD*. This caused issues with CRIU
checkpoint, which expects that /dev/kfd will be open if
/dev/dri/renderD* is.

As a workaround for the CRIU behaviour, leave /dev/kfd open
when closing hsa.

Signed-off-by: David Francis <David.Francis@amd.com>
Change-Id: Ie1b2d5b1d8986750b0e560ae2934b7c73cff942e

src/globals.c

@@ -27,7 +27,7 @@
 
 // HSAKMT global data
 
-int kfd_fd;
+int kfd_fd = -1;
 unsigned long kfd_open_count;
 unsigned long system_properties_count;
 pthread_mutex_t hsakmt_mutex = PTHREAD_MUTEX_INITIALIZER;

src/openclose.c

@@ -99,7 +99,7 @@ static void clear_after_fork(void)
 	destroy_device_debugging_memory();
 	if (kfd_fd) {
 		close(kfd_fd);
-		kfd_fd = 0;
+		kfd_fd = -1;
 	}
 	kfd_open_count = 0;
 	parent_pid = -1;
@@ -160,15 +160,17 @@ HSAKMT_STATUS HSAKMTAPI hsaKmtOpenKFD(void)
 		if (result != HSAKMT_STATUS_SUCCESS)
 			goto open_failed;
 
-		fd = open(kfd_device_name, O_RDWR | O_CLOEXEC);
+		if (kfd_fd < 0) {
+			fd = open(kfd_device_name, O_RDWR | O_CLOEXEC);
 
-		if (fd == -1) {
-			result = HSAKMT_STATUS_KERNEL_IO_CHANNEL_NOT_OPENED;
-			goto open_failed;
+			if (fd == -1) {
+				result = HSAKMT_STATUS_KERNEL_IO_CHANNEL_NOT_OPENED;
+				goto open_failed;
+			}
+
+			kfd_fd = fd;
 		}
 
-		kfd_fd = fd;
-
 		init_page_size();
 
 		result = init_kfd_version();
@@ -223,10 +225,6 @@ HSAKMT_STATUS HSAKMTAPI hsaKmtCloseKFD(void)
 		if (--kfd_open_count == 0) {
 			destroy_counter_props();
 			destroy_device_debugging_memory();
-			if (kfd_fd) {
-				close(kfd_fd);
-				kfd_fd = 0;
-			}
 		}
 
 		result = HSAKMT_STATUS_SUCCESS;