Re: [PATCHv2 1/9] mm: Introduce new vm_insert_range and vm_insert_range_buggy API

Souptick Joarder
2019-01-31T12:31:52Z

On Thu, Jan 31, 2019 at 5:37 PM Heiko Stuebner <heiko@sntech.de> wrote:
>
> Am Donnerstag, 31. Januar 2019, 04:08:12 CET schrieb Souptick Joarder:
> > 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.
> >
> > Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
> > Suggested-by: Russell King <linux@armlinux.org.uk>
> > Suggested-by: Matthew Wilcox <willy@infradead.org>
>
> hmm, I'm missing a changelog here between v1 and v2.
> Nevertheless I managed to test v1 on Rockchip hardware
> and display is still working, including talking to Lima via prime.
>
> So if there aren't any big changes for v2, on Rockchip
> Tested-by: Heiko Stuebner <heiko@sntech.de>

Change log is available in [0/9].
Patch [1/9] & [4/9] have no changes between v1 -> v2.