diff options
Diffstat (limited to 'include/asm-powerpc/pgtable-64k.h')
| -rw-r--r-- | include/asm-powerpc/pgtable-64k.h | 39 |
1 files changed, 38 insertions, 1 deletions
diff --git a/include/asm-powerpc/pgtable-64k.h b/include/asm-powerpc/pgtable-64k.h index bd54b772fbc..1cbd6b377ee 100644 --- a/include/asm-powerpc/pgtable-64k.h +++ b/include/asm-powerpc/pgtable-64k.h @@ -13,12 +13,49 @@ #define PTE_TABLE_SIZE (sizeof(real_pte_t) << PTE_INDEX_SIZE) #define PMD_TABLE_SIZE (sizeof(pmd_t) << PMD_INDEX_SIZE) #define PGD_TABLE_SIZE (sizeof(pgd_t) << PGD_INDEX_SIZE) -#endif /* __ASSEMBLY__ */ #define PTRS_PER_PTE (1 << PTE_INDEX_SIZE) #define PTRS_PER_PMD (1 << PMD_INDEX_SIZE) #define PTRS_PER_PGD (1 << PGD_INDEX_SIZE) +#ifdef CONFIG_PPC_SUBPAGE_PROT +/* + * For the sub-page protection option, we extend the PGD with one of + * these. Basically we have a 3-level tree, with the top level being + * the protptrs array. To optimize speed and memory consumption when + * only addresses < 4GB are being protected, pointers to the first + * four pages of sub-page protection words are stored in the low_prot + * array. + * Each page of sub-page protection words protects 1GB (4 bytes + * protects 64k). For the 3-level tree, each page of pointers then + * protects 8TB. + */ +struct subpage_prot_table { + unsigned long maxaddr; /* only addresses < this are protected */ + unsigned int **protptrs[2]; + unsigned int *low_prot[4]; +}; + +#undef PGD_TABLE_SIZE +#define PGD_TABLE_SIZE ((sizeof(pgd_t) << PGD_INDEX_SIZE) + \ + sizeof(struct subpage_prot_table)) + +#define SBP_L1_BITS (PAGE_SHIFT - 2) +#define SBP_L2_BITS (PAGE_SHIFT - 3) +#define SBP_L1_COUNT (1 << SBP_L1_BITS) +#define SBP_L2_COUNT (1 << SBP_L2_BITS) +#define SBP_L2_SHIFT (PAGE_SHIFT + SBP_L1_BITS) +#define SBP_L3_SHIFT (SBP_L2_SHIFT + SBP_L2_BITS) + +extern void subpage_prot_free(pgd_t *pgd); + +static inline struct subpage_prot_table *pgd_subpage_prot(pgd_t *pgd) +{ + return (struct subpage_prot_table *)(pgd + PTRS_PER_PGD); +} +#endif /* CONFIG_PPC_SUBPAGE_PROT */ +#endif /* __ASSEMBLY__ */ + /* With 4k base page size, hugepage PTEs go at the PMD level */ #define MIN_HUGEPTE_SHIFT PAGE_SHIFT |