[PATCH V1] Revert "accel/amdxdna: Support read-only user-pointer BO mappings"

[Lizhi Hou]

This reverts commit f649e63d4a6423eda8eb208638849fd6396aedd7.

The read-only feature requires further consideration.

Signed-off-by: Lizhi Hou <lizhi.hou@xxxxxxx>
---
 drivers/accel/amdxdna/amdxdna_ubuf.c | 29 ++--------------------------
 1 file changed, 2 insertions(+), 27 deletions(-)

diff --git a/drivers/accel/amdxdna/amdxdna_ubuf.c b/drivers/accel/amdxdna/amdxdna_ubuf.c
index 3769210c55cc..4c0647057759 100644
--- a/drivers/accel/amdxdna/amdxdna_ubuf.c
+++ b/drivers/accel/amdxdna/amdxdna_ubuf.c
@@ -125,26 +125,6 @@ static const struct dma_buf_ops amdxdna_ubuf_dmabuf_ops = {
 	.vunmap = amdxdna_ubuf_vunmap,
 };
 
-static int readonly_va_entry(struct amdxdna_drm_va_entry *va_ent)
-{
-	struct mm_struct *mm = current->mm;
-	struct vm_area_struct *vma;
-	int ret;
-
-	mmap_read_lock(mm);
-
-	vma = find_vma(mm, va_ent->vaddr);
-	if (!vma ||
-	    vma->vm_start > va_ent->vaddr ||
-	    vma->vm_end - va_ent->vaddr < va_ent->len)
-		ret = -ENOENT;
-	else
-		ret = vma->vm_flags & VM_WRITE ? 0 : 1;
-
-	mmap_read_unlock(mm);
-	return ret;
-}
-
 struct dma_buf *amdxdna_get_ubuf(struct drm_device *dev,
 				 u32 num_entries, void __user *va_entries)
 {
@@ -154,7 +134,6 @@ struct dma_buf *amdxdna_get_ubuf(struct drm_device *dev,
 	struct amdxdna_ubuf_priv *ubuf;
 	u32 npages, start = 0;
 	struct dma_buf *dbuf;
-	bool readonly = true;
 	int i, ret;
 	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 
@@ -193,10 +172,6 @@ struct dma_buf *amdxdna_get_ubuf(struct drm_device *dev,
 			ret = -EINVAL;
 			goto free_ent;
 		}
-
-		/* Pin pages as writable as long as not all entries are read-only. */
-		if (readonly && readonly_va_entry(&va_ent[i]) != 1)
-			readonly = false;
 	}
 
 	ubuf->nr_pages = exp_info.size >> PAGE_SHIFT;
@@ -219,7 +194,7 @@ struct dma_buf *amdxdna_get_ubuf(struct drm_device *dev,
 		npages = va_ent[i].len >> PAGE_SHIFT;
 
 		ret = pin_user_pages_fast(va_ent[i].vaddr, npages,
-					  (readonly ? 0 : FOLL_WRITE) | FOLL_LONGTERM,
+					  FOLL_WRITE | FOLL_LONGTERM,
 					  &ubuf->pages[start]);
 		if (ret >= 0) {
 			start += ret;
@@ -236,7 +211,7 @@ struct dma_buf *amdxdna_get_ubuf(struct drm_device *dev,
 
 	exp_info.ops = &amdxdna_ubuf_dmabuf_ops;
 	exp_info.priv = ubuf;
-	exp_info.flags = (readonly ? O_RDONLY : O_RDWR) | O_CLOEXEC;
+	exp_info.flags = O_RDWR | O_CLOEXEC;
 
 	dbuf = dma_buf_export(&exp_info);
 	if (IS_ERR(dbuf)) {
-- 
2.34.1