Use vm_insert_range and vm_insert_range_buggy

Previouly drivers have their own way of mapping range of kernel pages/memory into user vma and this was done by invoking vm_insert_page() within a loop.

As this pattern is common across different drivers, it can be generalized by creating new functions and use it across the drivers.

vm_insert_range() is the API which could be used to mapped kernel memory/pages in drivers which has considered vm_pgoff

vm_insert_range_buggy() is the API which could be used to map range of kernel memory/pages in drivers which has not considered vm_pgoff. vm_pgoff is passed default as 0 for those drivers.

We _could_ then at a later "fix" these drivers which are using vm_insert_range_buggy() to behave according to the normal vm_pgoff offsetting simply by removing the _buggy suffix on the function name and if that causes regressions, it gives us an easy way to revert.

v1 -> v2:
Few Reviewed-by.

Updated the change log in [8/9]

In [7/9], vm_pgoff is treated in V4L2 API as a 'cookie' to select a buffer, not as a in-buffer offset by design and it always want to mmap a whole buffer from its beginning. Added additional changes after discussing with Marek and vm_insert_range could be used instead of vm_insert_range_buggy.

Souptick Joarder (9):
mm: Introduce new vm_insert_range and vm_insert_range_buggy API arch/arm/mm/dma-mapping.c: Convert to use vm_insert_range drivers/firewire/core-iso.c: Convert to use vm_insert_range_buggy drm/rockchip/rockchip_drm_gem.c: Convert to use vm_insert_range drm/xen/xen_drm_front_gem.c: Convert to use vm_insert_range iommu/dma-iommu.c: Convert to use vm_insert_range videobuf2/videobuf2-dma-sg.c: Convert to use vm_insert_range xen/gntdev.c: Convert to use vm_insert_range xen/privcmd-buf.c: Convert to use vm_insert_range_buggy

 arch/arm/mm/dma-mapping.c                          | 22 ++----
 drivers/firewire/core-iso.c                        | 15 +---
 drivers/gpu/drm/rockchip/rockchip_drm_gem.c        | 17 +----
 drivers/gpu/drm/xen/xen_drm_front_gem.c            | 18 ++---
 drivers/iommu/dma-iommu.c                          | 12 +---
 drivers/media/common/videobuf2/videobuf2-core.c    |  7 ++
 .../media/common/videobuf2/videobuf2-dma-contig.c  |  6 --
 drivers/media/common/videobuf2/videobuf2-dma-sg.c  | 22 ++----
 drivers/xen/gntdev.c                               | 16 ++---
 drivers/xen/privcmd-buf.c                          |  8 +--
 include/linux/mm.h                                 |  4 ++
 mm/memory.c                                        | 81 ++++++++++++++++++++++
 mm/nommu.c                                         | 14 ++++
 13 files changed, 136 insertions(+), 106 deletions(-)

1.9.1