Open source GPL/LGPL release

drivers/gpu/nvgpu/os/linux/module_usermode.c

@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2017-2021, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <nvgpu/types.h>
+
+#include "os_linux.h"
+
+/*
+ * Locks out the driver from accessing GPU registers. This prevents access to
+ * thse registers after the GPU has been clock or power gated. This should help
+ * find annoying bugs where register reads and writes are silently dropped
+ * after the GPU has been turned off. On older chips these reads and writes can
+ * also lock the entire CPU up.
+ */
+void nvgpu_lockout_usermode_registers(struct gk20a *g)
+{
+	g->usermode_regs = 0U;
+}
+
+/*
+ * Undoes t19x_lockout_registers().
+ */
+void nvgpu_restore_usermode_registers(struct gk20a *g)
+{
+	g->usermode_regs = g->usermode_regs_saved;
+}
+
+void nvgpu_remove_usermode_support(struct gk20a *g)
+{
+	if (g->usermode_regs) {
+		g->usermode_regs = 0U;
+	}
+}
+
+void nvgpu_init_usermode_support(struct gk20a *g)
+{
+	if (g->ops.usermode.base == NULL) {
+		return;
+	}
+
+	if (g->usermode_regs == 0U) {
+		g->usermode_regs = g->regs + g->ops.usermode.bus_base(g);
+		g->usermode_regs_saved = g->usermode_regs;
+	}
+
+	g->usermode_regs_bus_addr = g->regs_bus_addr +
+					g->ops.usermode.bus_base(g);
+}