Re: [PATCH V2] accel/amdxdna: Remove mmap and export support for ubuf

[Lizhi Hou]

Applied to drm-misc-fixes

On 5/18/26 23:42, Christian König wrote:

On 5/18/26 17:57, Lizhi Hou wrote:

Ubuf pages should not be mmaped or exported. Remove the ubuf mmap callback
and return -EOPNOTSUPP when exporting ubuf objects.

ubuf vmap is also removed for there is not a real use case yet.

Fixes: bd72d4acda10 ("accel/amdxdna: Support user space allocated buffer")
Cc: Christian Koenig <christian.koe...@amd.com>
Signed-off-by: Lizhi Hou <lizhi....@amd.com>

Reviewed-by: Christian König <christian.koe...@amd.com>

---
v2:
   Remove dead code amdxdna_ubuf_vm_ops structure and amdxdna_ubuf_vm_fault
   function.
   Rename Non-exportable buffer flag from 'pri' to 'private_buffer'

  drivers/accel/amdxdna/amdxdna_gem.c  |  9 ++++-
  drivers/accel/amdxdna/amdxdna_gem.h  |  2 ++
  drivers/accel/amdxdna/amdxdna_ubuf.c | 50 ----------------------------
  3 files changed, 10 insertions(+), 51 deletions(-)

diff --git a/drivers/accel/amdxdna/amdxdna_gem.c 
b/drivers/accel/amdxdna/amdxdna_gem.c
index 319d2064fafa..6b9b556de555 100644
--- a/drivers/accel/amdxdna/amdxdna_gem.c
+++ b/drivers/accel/amdxdna/amdxdna_gem.c
@@ -492,6 +492,9 @@ static struct dma_buf *amdxdna_gem_prime_export(struct 
drm_gem_object *gobj, int
        struct amdxdna_gem_obj *abo = to_xdna_obj(gobj);
        DEFINE_DMA_BUF_EXPORT_INFO(exp_info);

+ if (abo->private_buffer)

+               return ERR_PTR(-EOPNOTSUPP);
+
        if (abo->dma_buf) {
                get_dma_buf(abo->dma_buf);
                return abo->dma_buf;
@@ -716,6 +719,7 @@ amdxdna_gem_create_ubuf_object(struct drm_device *dev, 
struct amdxdna_drm_create
  {
        struct amdxdna_dev *xdna = to_xdna_dev(dev);
        struct amdxdna_drm_va_tbl va_tbl;
+       struct amdxdna_gem_obj *abo;
        struct drm_gem_object *gobj;
        struct dma_buf *dma_buf;

@@ -742,7 +746,10 @@ amdxdna_gem_create_ubuf_object(struct drm_device *dev, struct amdxdna_drm_create dma_buf_put(dma_buf); - return to_xdna_obj(gobj);

+       abo = to_xdna_obj(gobj);
+       abo->private_buffer = true;
+
+       return abo;
  }

static struct amdxdna_gem_obj *

diff --git a/drivers/accel/amdxdna/amdxdna_gem.h 
b/drivers/accel/amdxdna/amdxdna_gem.h
index 4fc48a1189d2..957305ccb485 100644
--- a/drivers/accel/amdxdna/amdxdna_gem.h
+++ b/drivers/accel/amdxdna/amdxdna_gem.h
@@ -54,6 +54,8 @@ struct amdxdna_gem_obj {

/* True, if BO is managed by XRT, not application */

        bool                            internal;
+       /* True, if BO is not exportable */
+       bool                            private_buffer;
  };

#define to_gobj(obj) (&(obj)->base.base)

diff --git a/drivers/accel/amdxdna/amdxdna_ubuf.c 
b/drivers/accel/amdxdna/amdxdna_ubuf.c
index 3769210c55cc..bb60fb80467e 100644
--- a/drivers/accel/amdxdna/amdxdna_ubuf.c
+++ b/drivers/accel/amdxdna/amdxdna_ubuf.c
@@ -69,60 +69,10 @@ static void amdxdna_ubuf_release(struct dma_buf *dbuf)
        kfree(ubuf);
  }

-static vm_fault_t amdxdna_ubuf_vm_fault(struct vm_fault *vmf)

-{
-       struct vm_area_struct *vma = vmf->vma;
-       struct amdxdna_ubuf_priv *ubuf;
-       unsigned long pfn;
-       pgoff_t pgoff;
-
-       ubuf = vma->vm_private_data;
-       pgoff = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
-
-       pfn = page_to_pfn(ubuf->pages[pgoff]);
-       return vmf_insert_pfn(vma, vmf->address, pfn);
-}
-
-static const struct vm_operations_struct amdxdna_ubuf_vm_ops = {
-       .fault = amdxdna_ubuf_vm_fault,
-};
-
-static int amdxdna_ubuf_mmap(struct dma_buf *dbuf, struct vm_area_struct *vma)
-{
-       struct amdxdna_ubuf_priv *ubuf = dbuf->priv;
-
-       vma->vm_ops = &amdxdna_ubuf_vm_ops;
-       vma->vm_private_data = ubuf;
-       vm_flags_set(vma, VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP);
-
-       return 0;
-}
-
-static int amdxdna_ubuf_vmap(struct dma_buf *dbuf, struct iosys_map *map)
-{
-       struct amdxdna_ubuf_priv *ubuf = dbuf->priv;
-       void *kva;
-
-       kva = vmap(ubuf->pages, ubuf->nr_pages, VM_MAP, PAGE_KERNEL);
-       if (!kva)
-               return -EINVAL;
-
-       iosys_map_set_vaddr(map, kva);
-       return 0;
-}
-
-static void amdxdna_ubuf_vunmap(struct dma_buf *dbuf, struct iosys_map *map)
-{
-       vunmap(map->vaddr);
-}
-
  static const struct dma_buf_ops amdxdna_ubuf_dmabuf_ops = {
        .map_dma_buf = amdxdna_ubuf_map,
        .unmap_dma_buf = amdxdna_ubuf_unmap,
        .release = amdxdna_ubuf_release,
-       .mmap = amdxdna_ubuf_mmap,
-       .vmap = amdxdna_ubuf_vmap,
-       .vunmap = amdxdna_ubuf_vunmap,
  };

static int readonly_va_entry(struct amdxdna_drm_va_entry *va_ent)