Messages in this thread | | | Subject | Re: [PATCHv2 02/29] asm-generic: introduce 5level-fixup.h | From | Vlastimil Babka <> | Date | Fri, 27 Jan 2017 12:06:02 +0100 |
| |
On 12/27/2016 02:53 AM, Kirill A. Shutemov wrote: > We are going to switch core MM to 5-level paging abstraction. > > This is preparation step which adds <asm-generic/5level-fixup.h> > As with 4level-fixup.h, the new header allows quickly make all > architectures compatible with 5-level paging in core MM. > > In long run we would like to switch architectures to properly folded p4d > level by using <asm-generic/pgtable-nop4d.h>, but it requires more > changes to arch-specific code. > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > --- > include/asm-generic/4level-fixup.h | 3 ++- > include/asm-generic/5level-fixup.h | 41 ++++++++++++++++++++++++++++++++++++++ > include/linux/mm.h | 3 +++ > 3 files changed, 46 insertions(+), 1 deletion(-) > create mode 100644 include/asm-generic/5level-fixup.h > > diff --git a/include/asm-generic/4level-fixup.h b/include/asm-generic/4level-fixup.h > index 5bdab6bffd23..928fd66b1271 100644 > --- a/include/asm-generic/4level-fixup.h > +++ b/include/asm-generic/4level-fixup.h > @@ -15,7 +15,6 @@ > ((unlikely(pgd_none(*(pud))) && __pmd_alloc(mm, pud, address))? \ > NULL: pmd_offset(pud, address)) > > -#define pud_alloc(mm, pgd, address) (pgd)
This...
> #define pud_offset(pgd, start) (pgd) > #define pud_none(pud) 0 > #define pud_bad(pud) 0 > @@ -35,4 +34,6 @@ > #undef pud_addr_end > #define pud_addr_end(addr, end) (end) > > +#include <asm-generic/5level-fixup.h>
... plus this...
> + > #endif > diff --git a/include/asm-generic/5level-fixup.h b/include/asm-generic/5level-fixup.h > new file mode 100644 > index 000000000000..b5ca82dc4175 > --- /dev/null > +++ b/include/asm-generic/5level-fixup.h > @@ -0,0 +1,41 @@ > +#ifndef _5LEVEL_FIXUP_H > +#define _5LEVEL_FIXUP_H > + > +#define __ARCH_HAS_5LEVEL_HACK > +#define __PAGETABLE_P4D_FOLDED > + > +#define P4D_SHIFT PGDIR_SHIFT > +#define P4D_SIZE PGDIR_SIZE > +#define P4D_MASK PGDIR_MASK > +#define PTRS_PER_P4D 1 > + > +#define p4d_t pgd_t > + > +#define pud_alloc(mm, p4d, address) \ > + ((unlikely(pgd_none(*(p4d))) && __pud_alloc(mm, p4d, address)) ? \ > + NULL : pud_offset(p4d, address))
... and this, makes me wonder if that broke pud_alloc() for architectures that use the 4level-fixup.h. Don't those need to continue having pud_alloc() as (pgd)?
| |