/*
* A linux PTE was changed and the corresponding hash table entry
* neesd to be flushed. This function will either perform the flush
* immediately or will batch it up if the current CPU has an active
* batch on it.
*
* Must be called from within some kind of spinlock/non-preempt region...
*/
void hpte_need_flush(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, unsigned long pte, int huge)
{
struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch);
unsigned long vsid, vaddr;
unsigned int psize;
int ssize;
real_pte_t rpte;
int i;
i = batch->index;
/* We mask the address for the base page size. Huge pages will
* have applied their own masking already
*/
addr &= PAGE_MASK;
/* Get page size (maybe move back to caller).
*
* NOTE: when using special 64K mappings in 4K environment like
* for SPEs, we obtain the page size from the slice, which thus
* must still exist (and thus the VMA not reused) at the time
* of this call
*/
if (huge) {
#ifdef CONFIG_HUGETLB_PAGE
psize = get_slice_psize(mm, addr);
#else
BUG();
psize = pte_pagesize_index(mm, addr, pte); /* shutup gcc */
#endif
} else
psize = pte_pagesize_index(mm, addr, pte);
/* Build full vaddr */
if (!is_kernel_addr(addr)) {
ssize = user_segment_size(addr);
vsid = get_vsid(mm->context.id, addr, ssize);
WARN_ON(vsid == 0);
} else {
vsid = get_kernel_vsid(addr, mmu_kernel_ssize);
ssize = mmu_kernel_ssize;
}
vaddr = hpt_va(addr, vsid, ssize);
rpte = __real_pte(__pte(pte), ptep);
/*
* Check if we have an active batch on this CPU. If not, just
* flush now and return. For now, we don global invalidates
* in that case, might be worth testing the mm cpu mask though
* and decide to use local invalidates instead...
*/
if (!batch->active) {
flush_hash_page(vaddr, rpte, psize, ssize, 0);
return;
}
/*
* This can happen when we are in the middle of a TLB batch and
* we encounter memory pressure (eg copy_page_range when it tries
* to allocate a new pte). If we have to reclaim memory and end
* up scanning and resetting referenced bits then our batch context
* will change mid stream.
*
* We also need to ensure only one page size is present in a given
* batch
*/
if (i != 0 && (mm != batch->mm || batch->psize != psize ||
batch->ssize != ssize)) {
__flush_tlb_pending(batch);
i = 0;
}
if (i == 0) {
batch->mm = mm;
batch->psize = psize;
batch->ssize = ssize;
}
batch->pte[i] = rpte;
batch->vaddr[i] = vaddr;
batch->index = ++i;
if (i >= PPC64_TLB_BATCH_NR)
__flush_tlb_pending(batch);
}
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 old_pte, new_pte;
unsigned long va, rflags, pa, sz;
long slot;
BUG_ON(shift != mmu_psize_defs[mmu_psize].shift);
/* Search the Linux page table for a match with va */
va = hpt_va(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(va, 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, va, mmu_psize,
ssize, local) == -1)
old_pte &= ~_PAGE_HPTEFLAGS;
}
if (likely(!(old_pte & _PAGE_HASHPTE))) {
unsigned long hash = hpt_hash(va, shift, ssize);
unsigned long hpte_group;
pa = pte_pfn(__pte(old_pte)) << PAGE_SHIFT;
repeat:
hpte_group = ((hash & htab_hash_mask) *
HPTES_PER_GROUP) & ~0x7UL;
/* 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));
/* Insert into the hash table, primary slot */
slot = ppc_md.hpte_insert(hpte_group, va, pa, rflags, 0,
mmu_psize, ssize);
/* Primary is full, try the secondary */
if (unlikely(slot == -1)) {
hpte_group = ((~hash & htab_hash_mask) *
HPTES_PER_GROUP) & ~0x7UL;
slot = ppc_md.hpte_insert(hpte_group, va, pa, rflags,
HPTE_V_SECONDARY,
mmu_psize, ssize);
if (slot == -1) {
if (mftb() & 0x1)
hpte_group = ((hash & htab_hash_mask) *
HPTES_PER_GROUP)&~0x7UL;
ppc_md.hpte_remove(hpte_group);
goto repeat;
}
}
/*
* 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, 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;
}
