129 lines
3.8 KiB
C
129 lines
3.8 KiB
C
/*
|
|
* PPC64 Huge TLB Page Support for hash based MMUs (POWER4 and later)
|
|
*
|
|
* Copyright (C) 2003 David Gibson, IBM Corporation.
|
|
*
|
|
* Based on the IA-32 version:
|
|
* Copyright (C) 2002, Rohit Seth <rohit.seth@intel.com>
|
|
*/
|
|
|
|
#include <linux/mm.h>
|
|
#include <linux/hugetlb.h>
|
|
#include <asm/pgtable.h>
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/cacheflush.h>
|
|
#include <asm/machdep.h>
|
|
|
|
extern long hpte_insert_repeating(unsigned long hash, unsigned long vpn,
|
|
unsigned long pa, unsigned long rlags,
|
|
unsigned long vflags, int psize, int ssize);
|
|
|
|
int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid,
|
|
pte_t *ptep, unsigned long trap, int local, int ssize,
|
|
unsigned int shift, unsigned int mmu_psize)
|
|
{
|
|
unsigned long vpn;
|
|
unsigned long old_pte, new_pte;
|
|
unsigned long rflags, pa, sz;
|
|
long slot;
|
|
|
|
BUG_ON(shift != mmu_psize_defs[mmu_psize].shift);
|
|
|
|
/* Search the Linux page table for a match with va */
|
|
vpn = hpt_vpn(ea, vsid, ssize);
|
|
|
|
/* At this point, we have a pte (old_pte) which can be used to build
|
|
* or update an HPTE. There are 2 cases:
|
|
*
|
|
* 1. There is a valid (present) pte with no associated HPTE (this is
|
|
* the most common case)
|
|
* 2. There is a valid (present) pte with an associated HPTE. The
|
|
* current values of the pp bits in the HPTE prevent access
|
|
* because we are doing software DIRTY bit management and the
|
|
* page is currently not DIRTY.
|
|
*/
|
|
|
|
|
|
do {
|
|
old_pte = pte_val(*ptep);
|
|
/* If PTE busy, retry the access */
|
|
if (unlikely(old_pte & _PAGE_BUSY))
|
|
return 0;
|
|
/* If PTE permissions don't match, take page fault */
|
|
if (unlikely(access & ~old_pte))
|
|
return 1;
|
|
/* Try to lock the PTE, add ACCESSED and DIRTY if it was
|
|
* a write access */
|
|
new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED;
|
|
if (access & _PAGE_RW)
|
|
new_pte |= _PAGE_DIRTY;
|
|
} while(old_pte != __cmpxchg_u64((unsigned long *)ptep,
|
|
old_pte, new_pte));
|
|
|
|
rflags = 0x2 | (!(new_pte & _PAGE_RW));
|
|
/* _PAGE_EXEC -> HW_NO_EXEC since it's inverted */
|
|
rflags |= ((new_pte & _PAGE_EXEC) ? 0 : HPTE_R_N);
|
|
sz = ((1UL) << shift);
|
|
if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
|
|
/* No CPU has hugepages but lacks no execute, so we
|
|
* don't need to worry about that case */
|
|
rflags = hash_page_do_lazy_icache(rflags, __pte(old_pte), trap);
|
|
|
|
/* Check if pte already has an hpte (case 2) */
|
|
if (unlikely(old_pte & _PAGE_HASHPTE)) {
|
|
/* There MIGHT be an HPTE for this pte */
|
|
unsigned long hash, slot;
|
|
|
|
hash = hpt_hash(vpn, shift, ssize);
|
|
if (old_pte & _PAGE_F_SECOND)
|
|
hash = ~hash;
|
|
slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
|
|
slot += (old_pte & _PAGE_F_GIX) >> 12;
|
|
|
|
if (ppc_md.hpte_updatepp(slot, rflags, vpn, mmu_psize,
|
|
mmu_psize, ssize, local) == -1)
|
|
old_pte &= ~_PAGE_HPTEFLAGS;
|
|
}
|
|
|
|
if (likely(!(old_pte & _PAGE_HASHPTE))) {
|
|
unsigned long hash = hpt_hash(vpn, shift, ssize);
|
|
|
|
pa = pte_pfn(__pte(old_pte)) << PAGE_SHIFT;
|
|
|
|
/* clear HPTE slot informations in new PTE */
|
|
#ifdef CONFIG_PPC_64K_PAGES
|
|
new_pte = (new_pte & ~_PAGE_HPTEFLAGS) | _PAGE_HPTE_SUB0;
|
|
#else
|
|
new_pte = (new_pte & ~_PAGE_HPTEFLAGS) | _PAGE_HASHPTE;
|
|
#endif
|
|
/* Add in WIMG bits */
|
|
rflags |= (new_pte & (_PAGE_WRITETHRU | _PAGE_NO_CACHE |
|
|
_PAGE_COHERENT | _PAGE_GUARDED));
|
|
/*
|
|
* enable the memory coherence always
|
|
*/
|
|
rflags |= HPTE_R_M;
|
|
|
|
slot = hpte_insert_repeating(hash, vpn, pa, rflags, 0,
|
|
mmu_psize, ssize);
|
|
|
|
/*
|
|
* Hypervisor failure. Restore old pte and return -1
|
|
* similar to __hash_page_*
|
|
*/
|
|
if (unlikely(slot == -2)) {
|
|
*ptep = __pte(old_pte);
|
|
hash_failure_debug(ea, access, vsid, trap, ssize,
|
|
mmu_psize, mmu_psize, old_pte);
|
|
return -1;
|
|
}
|
|
|
|
new_pte |= (slot << 12) & (_PAGE_F_SECOND | _PAGE_F_GIX);
|
|
}
|
|
|
|
/*
|
|
* No need to use ldarx/stdcx here
|
|
*/
|
|
*ptep = __pte(new_pte & ~_PAGE_BUSY);
|
|
return 0;
|
|
}
|