gpu: nvgpu: add ioctl for querying memory state

Add NVGPU_GPU_IOCTL_GET_MEMORY_STATE to read the amount of free
device-local video memory, if applicable.

Some reserved fields are added to support different types of queries in
the future (e.g. context-local free amount).

Bug 1787771
Bug 200233138

Change-Id: Id5ffd02ad4d6ed3a6dc196541938573c27b340ac
Signed-off-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-on: http://git-master/r/1223762
(cherry picked from commit 96221d96c7972c6387944603e974f7639d6dbe70)
Reviewed-on: http://git-master/r/1235980
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 23 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/ctrl_gk20a.c b/drivers/gpu/nvgpu/gk20a/ctrl_gk20a.c
index 6b832670..2fdf719a 100644
--- a/drivers/gpu/nvgpu/gk20a/ctrl_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/ctrl_gk20a.c
@@ -747,6 +747,24 @@ static int nvgpu_gpu_alloc_vidmem(struct gk20a *g,
         return 0;
 }
 
+static int nvgpu_gpu_get_memory_state(struct gk20a *g,
+                        struct nvgpu_gpu_get_memory_state_args *args)
+{
+        int err;
+
+        gk20a_dbg_fn("");
+
+        if (args->reserved[0] || args->reserved[1] ||
+            args->reserved[2] || args->reserved[3])
+                return -EINVAL;
+
+        err = gk20a_vidmem_get_space(g, &args->total_free_bytes);
+
+        gk20a_dbg_fn("done, err=%d, bytes=%lld", err, args->total_free_bytes);
+
+        return err;
+}
+
 long gk20a_ctrl_dev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
         struct device *dev = filp->private_data;
@@ -999,6 +1017,11 @@ long gk20a_ctrl_dev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg
                         (struct nvgpu_gpu_alloc_vidmem_args *)buf);
                 break;
 
+        case NVGPU_GPU_IOCTL_GET_MEMORY_STATE:
+                err = nvgpu_gpu_get_memory_state(g,
+                        (struct nvgpu_gpu_get_memory_state_args *)buf);
+                break;
+
         default:
                 dev_dbg(dev_from_gk20a(g), "unrecognized gpu ioctl cmd: 0x%x", cmd);
                 err = -ENOTTY;