gpu: nvgpu: track opened Linux ctrl files

An upcoming patch will need to enumerate opened ctrl nodes; track them
in a list, protected by a mutex.

Bug 200145225

Change-Id: I50dc15056832a3bb53fbdd7bd2bffcdaecc7b21c
Signed-off-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1811840
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Alex Waterman <alexw@nvidia.com>
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Vijayakumar Subbu <vsubbu@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

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

@@ -69,6 +69,9 @@ static void nvgpu_init_vars(struct gk20a *g)
 	/* Init the clock req count to 0 */
 	nvgpu_atomic_set(&g->clk_arb_global_nr, 0);
 
+	nvgpu_mutex_init(&l->ctrl.privs_lock);
+	nvgpu_init_list_node(&l->ctrl.privs);
+
 	l->regs_saved = l->regs;
 	l->bar1_saved = l->bar1;
 

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

@@ -55,8 +55,17 @@ struct gk20a_ctrl_priv {
 	struct device *dev;
 	struct gk20a *g;
 	struct nvgpu_clk_session *clk_session;
+
+	struct nvgpu_list_node list;
 };
 
+static inline struct gk20a_ctrl_priv *
+gk20a_ctrl_priv_from_list(struct nvgpu_list_node *node)
+{
+	return (struct gk20a_ctrl_priv *)
+		((uintptr_t)node - offsetof(struct gk20a_ctrl_priv, list));
+}
+
 static u32 gk20a_as_translate_as_alloc_flags(struct gk20a *g, u32 flags)
 {
 	u32 core_flags = 0;
@@ -105,20 +114,30 @@ int gk20a_ctrl_dev_open(struct inode *inode, struct file *filp)
 
 	err = nvgpu_clk_arb_init_session(g, &priv->clk_session);
 free_ref:
-	if (err) {
+	if (err != 0) {
 		gk20a_put(g);
 		if (priv)
 			nvgpu_kfree(g, priv);
+	} else {
+		nvgpu_mutex_acquire(&l->ctrl.privs_lock);
+		nvgpu_list_add(&priv->list, &l->ctrl.privs);
+		nvgpu_mutex_release(&l->ctrl.privs_lock);
 	}
+
 	return err;
 }
 int gk20a_ctrl_dev_release(struct inode *inode, struct file *filp)
 {
 	struct gk20a_ctrl_priv *priv = filp->private_data;
 	struct gk20a *g = priv->g;
+	struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
 
 	nvgpu_log_fn(g, " ");
 
+	nvgpu_mutex_acquire(&l->ctrl.privs_lock);
+	nvgpu_list_del(&priv->list);
+	nvgpu_mutex_release(&l->ctrl.privs_lock);
+
 	if (priv->clk_session)
 		nvgpu_clk_arb_release_session(g, priv->clk_session);
 

drivers/gpu/nvgpu/os/linux/os_linux.h

@@ -65,6 +65,10 @@ struct nvgpu_os_linux {
 	struct {
 		struct cdev cdev;
 		struct device *node;
+		/* see gk20a_ctrl_priv */
+		struct nvgpu_list_node privs;
+		/* guards modifications to the list and its contents */
+		struct nvgpu_mutex privs_lock;
 	} ctrl;
 
 	struct {

drivers/gpu/nvgpu/os/linux/vgpu/vgpu_linux.c

@@ -81,6 +81,9 @@ static void vgpu_init_vars(struct gk20a *g, struct gk20a_platform *platform)
 
 	nvgpu_mutex_init(&priv->vgpu_clk_get_freq_lock);
 
+	nvgpu_mutex_init(&l->ctrl.privs_lock);
+	nvgpu_init_list_node(&l->ctrl.privs);
+
 	l->regs_saved = l->regs;
 	l->bar1_saved = l->bar1;