gpu-paging: Functions to support initial working versionrtss22-aegpu-paging

- Buffer deallocation (+IOCTL)
- Buffer reallocation
- Private dmabuf user list and accessor

2 files changed, 20 insertions, 0 deletions

diff --git a/include/linux/nvmap.h b/include/linux/nvmap.h
index b8d267691..7a8181ca5 100644
--- a/include/linux/nvmap.h
+++ b/include/linux/nvmap.h
@@ -65,6 +65,24 @@ ulong nvmap_iovmm_get_used_pages(void);
 int nvmap_register_vidmem_carveout(struct device *dma_dev,
                 phys_addr_t base, size_t size);
 
+/* The following two functions are to help enable DRAM
+ * overprovising via paging. These functions allow the
+ * physical frames backing an nvmap dma_buf to be freed
+ * (for example, after their contents has been saved
+ * elsewhere by paging logic), and to be reallocated
+ * (such as when other code is ready to repopulate them).
+ * Both functions preserve any open nvmap handles.
+ */
+int nvmap_dealloc_dmabuf(struct dma_buf *dmabuf);
+int nvmap_realloc_dmabuf(struct dma_buf *dmabuf);
+
+/* Some drivers (such as nvgpu) store parallel structures
+ * for each dmabuf to track internal state. To allow these
+ * drivers to quickly access their state from a *dmabuf or
+ * FD, we allow them access to a per-dmabuf list_head.
+ */
+struct list_head* nvmap_get_priv_list(struct dma_buf *dmabuf);
+
 /*
  * A heap can be mapped to memory other than DRAM.
  * The HW, controls the memory, can be power gated/ungated
diff --git a/include/uapi/linux/nvmap.h b/include/uapi/linux/nvmap.h
index 66eda75ce..5fea19ac8 100644
--- a/include/uapi/linux/nvmap.h
+++ b/include/uapi/linux/nvmap.h
@@ -304,6 +304,8 @@ struct nvmap_handle_parameters {
  */
 #define NVMAP_IOC_FREE       _IO(NVMAP_IOC_MAGIC, 4)
 
+#define NVMAP_IOC_DEALLOC    _IO(NVMAP_IOC_MAGIC, 9)
+
 /* Maps the region of the specified handle into a user-provided virtual address
  * that was previously created via an mmap syscall on this fd */
 #define NVMAP_IOC_MMAP       _IOWR(NVMAP_IOC_MAGIC, 5, struct nvmap_map_caller)