Re: [Xen-devel] [Patch V6 12/16] mm: provide early_memremap_ro to establish read-only mapping

[Juergen Gross <jgross@xxxxxxxx>]

On 07/21/2015 06:49 AM, Juergen Gross wrote:
> Hi MM maintainers,
>
> this patch is the last requiring an ack for the series to go in.
> Could you please comment?
PING?

> Juergen
>
> On 07/17/2015 06:51 AM, Juergen Gross wrote:
> > During early boot as Xen pv domain the kernel needs to map some page
> > tables supplied by the hypervisor read only. This is needed to be
> > able to relocate some data structures conflicting with the physical
> > memory map especially on systems with huge RAM (above 512GB).
> >
> > Provide the function early_memremap_ro() to provide this read only
> > mapping.
> >
> > Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
> > Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@xxxxxxxxxx>
> > Cc: Arnd Bergmann <arnd@xxxxxxxx>
> > Cc: linux-mm@xxxxxxxxx
> > Cc: linux-arch@xxxxxxxxxxxxxxx
> > ---
> >   include/asm-generic/early_ioremap.h |  2 ++
> >   include/asm-generic/fixmap.h        |  3 +++
> >   mm/early_ioremap.c                  | 12 ++++++++++++
> >   3 files changed, 17 insertions(+)
> >
> > diff --git a/include/asm-generic/early_ioremap.h
> > b/include/asm-generic/early_ioremap.h
> > index a5de55c..316bd04 100644
> > --- a/include/asm-generic/early_ioremap.h
> > +++ b/include/asm-generic/early_ioremap.h
> > @@ -11,6 +11,8 @@ extern void __iomem *early_ioremap(resource_size_t
> > phys_addr,
> >                      unsigned long size);
> >   extern void *early_memremap(resource_size_t phys_addr,
> >                   unsigned long size);
> > +extern void *early_memremap_ro(resource_size_t phys_addr,
> > +                   unsigned long size);
> >   extern void early_iounmap(void __iomem *addr, unsigned long size);
> >   extern void early_memunmap(void *addr, unsigned long size);
> >
> > diff --git a/include/asm-generic/fixmap.h b/include/asm-generic/fixmap.h
> > index f23174f..1cbb833 100644
> > --- a/include/asm-generic/fixmap.h
> > +++ b/include/asm-generic/fixmap.h
> > @@ -46,6 +46,9 @@ static inline unsigned long virt_to_fix(const
> > unsigned long vaddr)
> >   #ifndef FIXMAP_PAGE_NORMAL
> >   #define FIXMAP_PAGE_NORMAL PAGE_KERNEL
> >   #endif
> > +#if !defined(FIXMAP_PAGE_RO) && defined(PAGE_KERNEL_RO)
> > +#define FIXMAP_PAGE_RO PAGE_KERNEL_RO
> > +#endif
> >   #ifndef FIXMAP_PAGE_NOCACHE
> >   #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NOCACHE
> >   #endif
> > diff --git a/mm/early_ioremap.c b/mm/early_ioremap.c
> > index e10ccd2..0cfadaf 100644
> > --- a/mm/early_ioremap.c
> > +++ b/mm/early_ioremap.c
> > @@ -217,6 +217,13 @@ early_memremap(resource_size_t phys_addr,
> > unsigned long size)
> >       return (__force void *)__early_ioremap(phys_addr, size,
> >                              FIXMAP_PAGE_NORMAL);
> >   }
> > +#ifdef FIXMAP_PAGE_RO
> > +void __init *
> > +early_memremap_ro(resource_size_t phys_addr, unsigned long size)
> > +{
> > +    return (__force void *)__early_ioremap(phys_addr, size,
> > FIXMAP_PAGE_RO);
> > +}
> > +#endif
> >   #else /* CONFIG_MMU */
> >
> >   void __init __iomem *
> > @@ -231,6 +238,11 @@ early_memremap(resource_size_t phys_addr,
> > unsigned long size)
> >   {
> >       return (void *)phys_addr;
> >   }
> > +void __init *
> > +early_memremap_ro(resource_size_t phys_addr, unsigned long size)
> > +{
> > +    return (void *)phys_addr;
> > +}
> >
> >   void __init early_iounmap(void __iomem *addr, unsigned long size)
> >   {
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel