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/* 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) \
remap_pfn_range((vma), (addr), (pfn), PAGE_SIZE, \
__pgprot(pgprot_val((prot)) | _PAGE_4K_PFN))
#endif /* __ASSEMBLY__ */
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