hugetlb_encode.h: fix undefined behaviour (34 << 26)

Left-shifting past the size of your datatype is undefined behaviour in C.
The literal 34 gets the type `int`, and that one is not big enough to

hugetlb_encode.h: fix undefined behaviour (34 << 26)

Left-shifting past the size of your datatype is undefined behaviour in C.
The literal 34 gets the type `int`, and that one is not big enough to be
left shifted by 26 bits.

An `unsigned` is long enough (on any machine that has at least 32 bits for
their ints.)

For uniformity, we mark all the literals as unsigned. But it's only
really needed for HUGETLB_FLAG_ENCODE_16GB.

Thanks to Randy Dunlap for an initial review and suggestion.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Matthias Goergens <[email protected]>
Acked-by: Randy Dunlap <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Muchun Song <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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powerpc/8xx: Support 16k hugepages with 4k pages

The 8xx has 4 page sizes: 4k, 16k, 512k and 8M

4k and 16k can be selected at build time as standard page sizes,
and 512k and 8M are hugepages.

When

powerpc/8xx: Support 16k hugepages with 4k pages

The 8xx has 4 page sizes: 4k, 16k, 512k and 8M

4k and 16k can be selected at build time as standard page sizes,
and 512k and 8M are hugepages.

When 4k standard pages are selected, 16k pages are not available.

Allow 16k pages as hugepages when 4k pages are used.

To allow that, implement arch_make_huge_pte() which receives
the necessary arguments to allow setting the PTE in accordance
with the page size:
- 512 k pages must have _PAGE_HUGE and _PAGE_SPS. They are set
by pte_mkhuge(). arch_make_huge_pte() does nothing.
- 16 k pages must have only _PAGE_SPS. arch_make_huge_pte() clears
_PAGE_HUGE.

Signed-off-by: Christophe Leroy <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/a518abc29266a708dfbccc8fce9ae6694fe4c2c6.1598862623.git.christophe.leroy@csgroup.eu

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mm/hugetlb: add mmap() encodings for 32MB and 512MB page sizes

ARM64 architecture also supports 32MB and 512MB HugeTLB page sizes. This
just adds mmap() system call argument encoding for them.

Lin

mm/hugetlb: add mmap() encodings for 32MB and 512MB page sizes

ARM64 architecture also supports 32MB and 512MB HugeTLB page sizes. This
just adds mmap() system call argument encoding for them.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Anshuman Khandual <[email protected]>
Acked-by: Punit Agrawal <[email protected]>
Acked-by: Mike Kravetz <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Catalin Marinas <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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mm: hugetlb: define system call hugetlb size encodings in single file

Patch series "Consolidate system call hugetlb page size encodings".

These patches are the result of discussions in
https://lkml

mm: hugetlb: define system call hugetlb size encodings in single file

Patch series "Consolidate system call hugetlb page size encodings".

These patches are the result of discussions in
https://lkml.org/lkml/2017/3/8/548. The following changes are made in the
patch set:

1) Put all the log2 encoded huge page size definitions in a common
header file. The idea is have a set of definitions that can be use as
the basis for system call specific definitions such as MAP_HUGE_* and
SHM_HUGE_*.

2) Remove MAP_HUGE_* definitions in arch specific files. All these
definitions are the same. Consolidate all definitions in the primary
user header file (uapi/linux/mman.h).

3) Remove SHM_HUGE_* definitions intended for user space from kernel
header file, and add to user (uapi/linux/shm.h) header file. Add
definitions for all known huge page size encodings as in mmap.

This patch (of 3):

If hugetlb pages are requested in mmap or shmget system calls, a huge
page size other than default can be requested. This is accomplished by
encoding the log2 of the huge page size in the upper bits of the flag
argument. asm-generic and arch specific headers all define the same
values for these encodings.

Put common definitions in a single header file. The primary uapi header
files for mmap and shm will use these definitions as a basis for
definitions specific to those system calls.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Mike Kravetz <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Michael Kerrisk <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Aneesh Kumar K.V <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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