diff options
author | Christophe Leroy <christophe.leroy@c-s.fr> | 2018-11-29 14:07:21 +0000 |
---|---|---|
committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-12-04 19:45:01 +1100 |
commit | 55c8fc3f4930286580af98711a481f35fa564e42 (patch) | |
tree | 72aec6a363562541e08d4a0bc94b30bcab3298e1 /arch/powerpc/include/asm/nohash/pgtable.h | |
parent | 3fb69c6a1a13afc5f64ef84e96d69a4be199d485 (diff) |
powerpc/8xx: reintroduce 16K pages with HW assistance
Using this HW assistance implies some constraints on the
page table structure:
- Regardless of the main page size used (4k or 16k), the
level 1 table (PGD) contains 1024 entries and each PGD entry covers
a 4Mbytes area which is managed by a level 2 table (PTE) containing
also 1024 entries each describing a 4k page.
- 16k pages require 4 identifical entries in the L2 table
- 512k pages PTE have to be spread every 128 bytes in the L2 table
- 8M pages PTE are at the address pointed by the L1 entry and each
8M page require 2 identical entries in the PGD.
In order to use hardware assistance with 16K pages, this patch does
the following modifications:
- Make PGD size independent of the main page size
- In 16k pages mode, redefine pte_t as a struct with 4 elements,
and populate those 4 elements in __set_pte_at() and pte_update()
- Adapt the size of the hugepage tables.
- Define a PTE_FRAGMENT_NB so that a 16k page contains 4 page tables.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/include/asm/nohash/pgtable.h')
-rw-r--r-- | arch/powerpc/include/asm/nohash/pgtable.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/nohash/pgtable.h b/arch/powerpc/include/asm/nohash/pgtable.h index 70ff23974b59..1ca1c1864b32 100644 --- a/arch/powerpc/include/asm/nohash/pgtable.h +++ b/arch/powerpc/include/asm/nohash/pgtable.h @@ -209,7 +209,11 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr, /* Anything else just stores the PTE normally. That covers all 64-bit * cases, and 32-bit non-hash with 32-bit PTEs. */ +#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PPC_16K_PAGES) + ptep->pte = ptep->pte1 = ptep->pte2 = ptep->pte3 = pte_val(pte); +#else *ptep = pte; +#endif /* * With hardware tablewalk, a sync is needed to ensure that |