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
Bug 200541476

Change-Id: I50dc15056832a3bb53fbdd7bd2bffcdaecc7b21c
Signed-off-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1811840
Reviewed-by: Alex Waterman <alexw@nvidia.com>
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-by: Vijayakumar Subbu <vsubbu@nvidia.com>
Signed-off-by: Debarshi Dutta <ddutta@nvidia.com>
(cherry picked from commit d53495400e15fdef80be2f04a9f2312b81d2bd6d
in dev-main)
Reviewed-on: https://git-master.nvidia.com/r/2170005
GVS: Gerrit_Virtual_Submit
Reviewed-by: Bibek Basu <bbasu@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

4 files changed, 30 insertions, 1 deletions

diff --git a/drivers/gpu/nvgpu/os/linux/driver_common.c b/drivers/gpu/nvgpu/os/linux/driver_common.c
index ea4dadac..c76dabeb 100644
--- a/drivers/gpu/nvgpu/os/linux/driver_common.c
+++ b/drivers/gpu/nvgpu/os/linux/driver_common.c
@@ -70,6 +70,9 @@ 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;
 
diff --git a/drivers/gpu/nvgpu/os/linux/ioctl_ctrl.c b/drivers/gpu/nvgpu/os/linux/ioctl_ctrl.c
index 3ccc6b0a..e85cec9c 100644
--- a/drivers/gpu/nvgpu/os/linux/ioctl_ctrl.c
+++ b/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);
 
diff --git a/drivers/gpu/nvgpu/os/linux/os_linux.h b/drivers/gpu/nvgpu/os/linux/os_linux.h
index d4b5a770..5880384a 100644
--- a/drivers/gpu/nvgpu/os/linux/os_linux.h
+++ b/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 {
diff --git a/drivers/gpu/nvgpu/os/linux/vgpu/vgpu_linux.c b/drivers/gpu/nvgpu/os/linux/vgpu/vgpu_linux.c
index 522f1b86..80bcfffb 100644
--- a/drivers/gpu/nvgpu/os/linux/vgpu/vgpu_linux.c
+++ b/drivers/gpu/nvgpu/os/linux/vgpu/vgpu_linux.c
@@ -73,6 +73,9 @@ 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;