diff options
Diffstat (limited to 'arch/powerpc/include/asm/pte-hash64-64k.h')
| -rw-r--r-- | arch/powerpc/include/asm/pte-hash64-64k.h | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/pte-hash64-64k.h b/arch/powerpc/include/asm/pte-hash64-64k.h new file mode 100644 index 00000000000..e05d26fa372 --- /dev/null +++ b/arch/powerpc/include/asm/pte-hash64-64k.h @@ -0,0 +1,115 @@ +/* To be include by pgtable-hash64.h only */ + +/* Additional PTE bits (don't change without checking asm in hash_low.S) */ +#define _PAGE_SPECIAL 0x00000400 /* software: special page */ +#define _PAGE_HPTE_SUB 0x0ffff000 /* combo only: sub pages HPTE bits */ +#define _PAGE_HPTE_SUB0 0x08000000 /* combo only: first sub page */ +#define _PAGE_COMBO 0x10000000 /* this is a combo 4k page */ +#define _PAGE_4K_PFN 0x20000000 /* PFN is for a single 4k page */ + +/* For 64K page, we don't have a separate _PAGE_HASHPTE bit. Instead, + * we set that to be the whole sub-bits mask. The C code will only + * test this, so a multi-bit mask will work. For combo pages, this + * is equivalent as effectively, the old _PAGE_HASHPTE was an OR of + * all the sub bits. For real 64k pages, we now have the assembly set + * _PAGE_HPTE_SUB0 in addition to setting the HIDX bits which overlap + * that mask. This is fine as long as the HIDX bits are never set on + * a PTE that isn't hashed, which is the case today. + * + * A little nit is for the huge page C code, which does the hashing + * in C, we need to provide which bit to use. + */ +#define _PAGE_HASHPTE _PAGE_HPTE_SUB + +/* Note the full page bits must be in the same location as for normal + * 4k pages as the same asssembly will be used to insert 64K pages + * wether the kernel has CONFIG_PPC_64K_PAGES or not + */ +#define _PAGE_F_SECOND 0x00008000 /* full page: hidx bits */ +#define _PAGE_F_GIX 0x00007000 /* full page: hidx bits */ + +/* PTE flags to conserve for HPTE identification */ +#define _PAGE_HPTEFLAGS (_PAGE_BUSY | _PAGE_HASHPTE | _PAGE_COMBO) + +/* Shift to put page number into pte. + * + * That gives us a max RPN of 34 bits, which means a max of 50 bits + * of addressable physical space, or 46 bits for the special 4k PFNs. + */ +#define PTE_RPN_SHIFT (30) + +#ifndef __ASSEMBLY__ + +/* + * With 64K pages on hash table, we have a special PTE format that + * uses a second "half" of the page table to encode sub-page information + * in order to deal with 64K made of 4K HW pages. Thus we override the + * generic accessors and iterators here + */ +#define __real_pte(e,p) ((real_pte_t) { \ + (e), pte_val(*((p) + PTRS_PER_PTE)) }) +#define __rpte_to_hidx(r,index) ((pte_val((r).pte) & _PAGE_COMBO) ? \ + (((r).hidx >> ((index)<<2)) & 0xf) : ((pte_val((r).pte) >> 12) & 0xf)) +#define __rpte_to_pte(r) ((r).pte) +#define __rpte_sub_valid(rpte, index) \ + (pte_val(rpte.pte) & (_PAGE_HPTE_SUB0 >> (index))) + +/* Trick: we set __end to va + 64k, which happens works for + * a 16M page as well as we want only one iteration + */ +#define pte_iterate_hashed_subpages(rpte, psize, va, index, shift) \ + do { \ + unsigned long __end = va + PAGE_SIZE; \ + unsigned __split = (psize == MMU_PAGE_4K || \ + psize == MMU_PAGE_64K_AP); \ + shift = mmu_psize_defs[psize].shift; \ + for (index = 0; va < __end; index++, va += (1L << shift)) { \ + if (!__split || __rpte_sub_valid(rpte, index)) do { \ + +#define pte_iterate_hashed_end() } while(0); } } while(0) + +#define pte_pagesize_index(mm, addr, pte) \ + (((pte) & _PAGE_COMBO)? MMU_PAGE_4K: MMU_PAGE_64K) + +#define remap_4k_pfn(vma, addr, pfn, prot) \ + remap_pfn_range((vma), (addr), (pfn), PAGE_SIZE, \ + __pgprot(pgprot_val((prot)) | _PAGE_4K_PFN)) + + +#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__ */ |