gpu: nvgpu: add vidmem allocation ioctl

Add NVGPU_GPU_IOCTL_ALLOC_VIDMEM to the ctrl fd for letting userspace
allocate on-board GPU memory (aka vidmem).  The allocations are returned
as dmabuf fds.

Also, report the amount of local video memory in the gpu
characteristics.

Jira DNVGPU-19
Jira DNVGPU-38

Change-Id: I28e361d31bb630b96d06bb1c86d022d91c7592bc
Signed-off-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-on: http://git-master/r/1181152
GVS: Gerrit_Virtual_Submit
Reviewed-by: Vijayakumar Subbu <vsubbu@nvidia.com>

1 files changed, 148 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/mm_gk20a.c b/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
index bf3d990c..2dcc4363 100644
--- a/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
@@ -411,6 +411,14 @@ struct gk20a_dmabuf_priv {
         u64 buffer_id;
 };
 
+struct gk20a_vidmem_buf {
+        struct gk20a *g;
+        struct mem_desc mem;
+        struct dma_buf *dmabuf;
+        void *dmabuf_priv;
+        void (*dmabuf_priv_delete)(void *);
+};
+
 static void gk20a_vm_remove_support_nofree(struct vm_gk20a *vm);
 
 static int gk20a_comptaglines_alloc(struct gk20a_comptag_allocator *allocator,
@@ -1833,6 +1841,146 @@ static u64 gk20a_vm_map_duplicate_locked(struct vm_gk20a *vm,
         return mapped_buffer->addr;
 }
 
+#if defined(CONFIG_GK20A_VIDMEM)
+static struct sg_table *gk20a_vidbuf_map_dma_buf(
+        struct dma_buf_attachment *attach, enum dma_data_direction dir)
+{
+        struct gk20a_vidmem_buf *buf = attach->dmabuf->priv;
+
+        return buf->mem.sgt;
+}
+
+static void gk20a_vidbuf_unmap_dma_buf(struct dma_buf_attachment *attach,
+                                       struct sg_table *sgt,
+                                       enum dma_data_direction dir)
+{
+}
+
+static void gk20a_vidbuf_release(struct dma_buf *dmabuf)
+{
+        struct gk20a_vidmem_buf *buf = dmabuf->priv;
+
+        gk20a_dbg_fn("");
+
+        if (buf->dmabuf_priv)
+                buf->dmabuf_priv_delete(buf->dmabuf_priv);
+
+        gk20a_gmmu_free(buf->g, &buf->mem);
+        kfree(buf);
+}
+
+static void *gk20a_vidbuf_kmap(struct dma_buf *dmabuf, unsigned long page_num)
+{
+        WARN_ON("Not supported");
+        return NULL;
+}
+
+static void *gk20a_vidbuf_kmap_atomic(struct dma_buf *dmabuf,
+                                      unsigned long page_num)
+{
+        WARN_ON("Not supported");
+        return NULL;
+}
+
+static int gk20a_vidbuf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
+{
+        return -EINVAL;
+}
+
+static int gk20a_vidbuf_set_private(struct dma_buf *dmabuf,
+                struct device *dev, void *priv, void (*delete)(void *priv))
+{
+        struct gk20a_vidmem_buf *buf = dmabuf->priv;
+
+        buf->dmabuf_priv = priv;
+        buf->dmabuf_priv_delete = delete;
+
+        return 0;
+}
+
+static void *gk20a_vidbuf_get_private(struct dma_buf *dmabuf,
+                struct device *dev)
+{
+        struct gk20a_vidmem_buf *buf = dmabuf->priv;
+
+        return buf->dmabuf_priv;
+}
+
+static const struct dma_buf_ops gk20a_vidbuf_ops = {
+        .map_dma_buf      = gk20a_vidbuf_map_dma_buf,
+        .unmap_dma_buf    = gk20a_vidbuf_unmap_dma_buf,
+        .release          = gk20a_vidbuf_release,
+        .kmap_atomic      = gk20a_vidbuf_kmap_atomic,
+        .kmap             = gk20a_vidbuf_kmap,
+        .mmap             = gk20a_vidbuf_mmap,
+        .set_drvdata      = gk20a_vidbuf_set_private,
+        .get_drvdata      = gk20a_vidbuf_get_private,
+};
+
+static struct dma_buf *gk20a_vidbuf_export(struct gk20a_vidmem_buf *buf)
+{
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 4, 0)
+        DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+
+        exp_info.priv = buf;
+        exp_info.ops = &gk20a_vidbuf_ops;
+        exp_info.size = buf->mem.size;
+        exp_info.flags = O_RDWR;
+
+        return dma_buf_export(&exp_info);
+#else
+        return dma_buf_export(buf, &gk20a_vidbuf_ops, buf->mem.size,
+                        O_RDWR, NULL);
+#endif
+}
+#endif
+
+int gk20a_vidmem_buf_alloc(struct gk20a *g, size_t bytes)
+{
+#if defined(CONFIG_GK20A_VIDMEM)
+        struct gk20a_vidmem_buf *buf;
+        int err, fd;
+
+        gk20a_dbg_fn("");
+
+        buf = kzalloc(sizeof(*buf), GFP_KERNEL);
+        if (!buf)
+                return -ENOMEM;
+
+        buf->g = g;
+
+        err = gk20a_gmmu_alloc_vid(g, bytes, &buf->mem);
+        if (err)
+                goto err_kfree;
+
+        buf->dmabuf = gk20a_vidbuf_export(buf);
+        if (IS_ERR(buf->dmabuf)) {
+                err = PTR_ERR(buf->dmabuf);
+                goto err_bfree;
+        }
+
+        fd = get_unused_fd_flags(O_RDWR);
+        if (fd < 0) {
+                /* ->release frees what we have done */
+                dma_buf_put(buf->dmabuf);
+                return fd;
+        }
+
+        /* fclose() on this drops one ref, freeing the dma buf */
+        fd_install(fd, buf->dmabuf->file);
+
+        return fd;
+
+err_bfree:
+        gk20a_gmmu_free(g, &buf->mem);
+err_kfree:
+        kfree(buf);
+        return err;
+#else
+        return -ENOSYS;
+#endif
+}
+
 u64 gk20a_vm_map(struct vm_gk20a *vm,
                         struct dma_buf *dmabuf,
                         u64 offset_align,