video: tegra: nvmap: add support to create RO handle from user VA

User malloc + mprotect/mmap a buffer as RO and
as part of alloc_from_va, user pass
the ACCESS_FLAGS as RO and expects  NvMap to give dma_buf_fd with
RO access.

Below are the conditions result in NvRmMemHandle creation -

1) VA: RO and Attr: RW
	- Don't create NvMap Handle
2) VA: RO and Attr: RO
	- Create NvMap Handle and set dma_buf_fd as RO
3) VA: RW and Attr: RO
	- Create NvMap Handle and set dma_buf_fd as RO
4) Mixed VA: RO + RW and Attr: RO
	- Create NvMap Handle with dma_buf_fd as RO for the whole
	  buffer
5) Mixed VA: RO + RW and Attr: RW
	- Don't Create NvMap Handle

If few pages of the buffer is set as RO and rest as RW,
multiple vma are created and vma->end and vma->start doesn't
differ by the buffer size, passed to create handle from VA.
Hence remove the check. Anyway the check is done in get_user_pages.

The change sets dma_buf_fd as RW/RO so that other process
should fetch the access permission just by reading f_mode
of dma_buf_fd.

Bug 200621238
Bug 200634660

Change-Id: I9c50c6f28664f0ff9f70dc08b15d93389e7d7201
Signed-off-by: Puneet Saxena <puneets@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvidia/+/2515023
(cherry picked from commit 0514e68ce8948428b417c55057a4dd2f57acd9c2)
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvidia/+/2521313
Reviewed-by: svc-mobile-coverity <svc-mobile-coverity@nvidia.com>
Reviewed-by: Bibek Basu <bbasu@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: Amulya Yarlagadda <ayarlagadda@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>
GVS: Gerrit_Virtual_Submit

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/nvmap.h b/include/linux/nvmap.h
index 8f17a1c48..b8d267691 100644
--- a/include/linux/nvmap.h
+++ b/include/linux/nvmap.h
@@ -50,6 +50,7 @@
 #define NVMAP_HANDLE_PHYS_CONTIG     (0x1ul << 6)
 #define NVMAP_HANDLE_CACHE_SYNC      (0x1ul << 7)
 #define NVMAP_HANDLE_CACHE_SYNC_AT_RESERVE      (0x1ul << 8)
+#define NVMAP_HANDLE_RO              (0x1ul << 9)
 
 #ifdef CONFIG_NVMAP_PAGE_POOLS
 ulong nvmap_page_pool_get_unused_pages(void);