From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Fabian=20Silva=20Delgado?= Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- arch/powerpc/include/asm/pte-hash64-64k.h | 102 ++++++++++++++++++++++++++++++ 1 file changed, 102 insertions(+) create mode 100644 arch/powerpc/include/asm/pte-hash64-64k.h (limited to 'arch/powerpc/include/asm/pte-hash64-64k.h') 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 000000000..4f4ec2ab4 --- /dev/null +++ b/arch/powerpc/include/asm/pte-hash64-64k.h @@ -0,0 +1,102 @@ +/* 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 assembly will be used to insert 64K pages + * whether 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 __real_pte +static inline real_pte_t __real_pte(pte_t pte, pte_t *ptep) +{ + real_pte_t rpte; + + rpte.pte = pte; + rpte.hidx = 0; + if (pte_val(pte) & _PAGE_COMBO) { + /* + * Make sure we order the hidx load against the _PAGE_COMBO + * check. The store side ordering is done in __hash_page_4K + */ + smp_rmb(); + rpte.hidx = pte_val(*((ptep) + PTRS_PER_PTE)); + } + return rpte; +} + +static inline unsigned long __rpte_to_hidx(real_pte_t rpte, unsigned long index) +{ + if ((pte_val(rpte.pte) & _PAGE_COMBO)) + return (rpte.hidx >> (index<<2)) & 0xf; + return (pte_val(rpte.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, vpn, index, shift) \ + do { \ + unsigned long __end = vpn + (1UL << (PAGE_SHIFT - VPN_SHIFT)); \ + unsigned __split = (psize == MMU_PAGE_4K || \ + psize == MMU_PAGE_64K_AP); \ + shift = mmu_psize_defs[psize].shift; \ + for (index = 0; vpn < __end; index++, \ + vpn += (1L << (shift - VPN_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) \ + (WARN_ON(((pfn) >= (1UL << (64 - PTE_RPN_SHIFT)))) ? -EINVAL : \ + remap_pfn_range((vma), (addr), (pfn), PAGE_SIZE, \ + __pgprot(pgprot_val((prot)) | _PAGE_4K_PFN))) + +#endif /* __ASSEMBLY__ */ -- cgit v1.2.3