gpu: nvgpu: Use a callback to free struct gk20a

struct gk20a is now part of nvgpu_os_linux in Linux builds. gk20a.c
still frees struct gk20a by kfree(struct gk20a *), which is wrong.
Create a new function pointer in struct gk20a for freeing the
structure and call kfree(struct nvgpu_os_linux *) instead.

JIRA NVGPU-259

Change-Id: I412ee993002cb2a42f0db015fc676de43418ec2f
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1591012
GVS: Gerrit_Virtual_Submit
Reviewed-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

drivers/gpu/nvgpu/common/linux/driver_common.c

@@ -274,3 +274,15 @@ void nvgpu_wait_for_deferred_interrupts(struct gk20a *g)
 				atomic_read(&l->sw_irq_nonstall_last_handled))
 		   <= 0, 0);
 }
+
+static void nvgpu_free_gk20a(struct gk20a *g)
+{
+	struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
+
+	kfree(l);
+}
+
+void nvgpu_init_gk20a(struct gk20a *g)
+{
+	g->free = nvgpu_free_gk20a;
+}

drivers/gpu/nvgpu/common/linux/driver_common.h

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2016-2017, 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/>.
+ */
+
+#ifndef NVGPU_LINUX_DRIVER_COMMON
+#define NVGPU_LINUX_DRIVER_COMMON
+
+void nvgpu_init_gk20a(struct gk20a *g);
+
+#endif

drivers/gpu/nvgpu/common/linux/module.c

@@ -53,6 +53,7 @@
 #include "cde_gm20b.h"
 #include "cde_gp10b.h"
 #include "ctxsw_trace.h"
+#include "driver_common.h"
 
 #define CLASS_NAME "nvidia-gpu"
 /* TODO: Change to e.g. "nvidia-gpu%s" once we have symlinks in place. */
@@ -1027,6 +1028,7 @@ static int gk20a_probe(struct platform_device *dev)
 	}
 
 	gk20a = &l->g;
+	nvgpu_init_gk20a(gk20a);
 	set_gk20a(dev, gk20a);
 	l->dev = &dev->dev;
 	gk20a->log_mask = NVGPU_DEFAULT_DBG_MASK;

drivers/gpu/nvgpu/common/linux/pci.c

@@ -37,6 +37,7 @@
 #endif
 
 #include "os_linux.h"
+#include "driver_common.h"
 
 #define PCI_INTERFACE_NAME "card-%s%%s"
 
@@ -457,6 +458,7 @@ static int nvgpu_pci_probe(struct pci_dev *pdev,
 	}
 
 	g = &l->g;
+	nvgpu_init_gk20a(g);
 
 	nvgpu_kmem_init(g);
 

drivers/gpu/nvgpu/gk20a/gk20a.c

@@ -518,7 +518,8 @@ static void gk20a_free_cb(struct nvgpu_ref *refcount)
 	if (g->remove_support)
 		g->remove_support(g);
 
-	kfree(g);
+	if (g->free)
+		g->free(g);
 }
 
 /**

drivers/gpu/nvgpu/gk20a/gk20a.h

@@ -1070,6 +1070,7 @@ struct nvgpu_gpu_params {
 };
 
 struct gk20a {
+	void (*free)(struct gk20a *g);
 	struct nvgpu_nvhost_dev *nvhost_dev;
 
 	/*

drivers/gpu/nvgpu/vgpu/vgpu.c

@@ -47,6 +47,7 @@
 #include "common/linux/os_linux.h"
 #include "common/linux/ioctl.h"
 #include "common/linux/scale.h"
+#include "common/linux/driver_common.h"
 
 #ifdef CONFIG_TEGRA_19x_GPU
 #include <vgpu/vgpu_t19x.h>
@@ -657,6 +658,7 @@ int vgpu_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	}
 	gk20a = &l->g;
+	nvgpu_init_gk20a(gk20a);
 
 	nvgpu_kmem_init(gk20a);