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, 20 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/mm_gk20a.c b/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
index f46f7a81..ff9bb5e2 100644
--- a/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
@@ -2276,6 +2276,26 @@ err_kfree:
 #endif
 }
 
+int gk20a_vidmem_get_space(struct gk20a *g, u64 *space)
+{
+#if defined(CONFIG_GK20A_VIDMEM)
+        struct gk20a_allocator *allocator = &g->mm.vidmem.allocator;
+
+        gk20a_dbg_fn("");
+
+        if (!gk20a_alloc_initialized(allocator))
+                return -ENOSYS;
+
+        mutex_lock(&g->mm.vidmem.clear_list_mutex);
+        *space = gk20a_alloc_space(allocator) +
+                atomic64_read(&g->mm.vidmem.bytes_pending);
+        mutex_unlock(&g->mm.vidmem.clear_list_mutex);
+        return 0;
+#else
+        return -ENOSYS;
+#endif
+}
+
 static u64 gk20a_mm_get_align(struct gk20a *g, struct scatterlist *sgl,
                               enum gk20a_aperture aperture)
 {