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Implement pmap_advise() for ARMv6/v7 pmap module

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Apply the given advice to the specified range of addresses within the
given pmap. Depending on the advice, clear the referenced and/or
modified flags in each mapping. Superpage within the given range will
be demoted or destroyed.

Reviewed by:	alc
Approved by:	cognet (mentor)
Approved by:	re
This commit is contained in:
zbb 2013-09-16 10:39:35 +00:00
parent 6b0cb8bbef
commit e1eb905487
1 changed files with 106 additions and 1 deletions
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107
sys/arm/arm/pmap-v6.c
View File

@ -4767,11 +4767,116 @@ pmap_is_modified(vm_page_t m)
}
/*
* This function is advisory.
* Apply the given advice to the specified range of addresses within the
* given pmap. Depending on the advice, clear the referenced and/or
* modified flags in each mapping.
*/
void
pmap_advise(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, int advice)
{
struct l2_bucket *l2b;
struct pv_entry *pve;
pd_entry_t *pl1pd, l1pd;
pt_entry_t *ptep, opte, pte;
vm_offset_t next_bucket;
vm_page_t m;
if (advice != MADV_DONTNEED && advice != MADV_FREE)
return;
rw_wlock(&pvh_global_lock);
PMAP_LOCK(pmap);
for (; sva < eva; sva = next_bucket) {
next_bucket = L2_NEXT_BUCKET(sva);
if (next_bucket < sva)
next_bucket = eva;
pl1pd = &pmap->pm_l1->l1_kva[L1_IDX(sva)];
l1pd = *pl1pd;
if ((l1pd & L1_TYPE_MASK) == L1_S_PROTO) {
if (pmap == pmap_kernel())
continue;
if (!pmap_demote_section(pmap, sva)) {
/*
* The large page mapping was destroyed.
*/
continue;
}
/*
* Unless the page mappings are wired, remove the
* mapping to a single page so that a subsequent
* access may repromote. Since the underlying
* l2_bucket is fully populated, this removal
* never frees an entire l2_bucket.
*/
l2b = pmap_get_l2_bucket(pmap, sva);
KASSERT(l2b != NULL,
("pmap_advise: no l2 bucket for "
"va 0x%#x, pmap 0x%p", sva, pmap));
ptep = &l2b->l2b_kva[l2pte_index(sva)];
opte = *ptep;
m = PHYS_TO_VM_PAGE(l2pte_pa(*ptep));
KASSERT(m != NULL,
("pmap_advise: no vm_page for demoted superpage"));
pve = pmap_find_pv(&m->md, pmap, sva);
KASSERT(pve != NULL,
("pmap_advise: no PV entry for managed mapping"));
if ((pve->pv_flags & PVF_WIRED) == 0) {
pmap_free_l2_bucket(pmap, l2b, 1);
pve = pmap_remove_pv(m, pmap, sva);
pmap_free_pv_entry(pmap, pve);
*ptep = 0;
PTE_SYNC(ptep);
if (pmap_is_current(pmap)) {
if (PTE_BEEN_EXECD(opte))
cpu_tlb_flushID_SE(sva);
else if (PTE_BEEN_REFD(opte))
cpu_tlb_flushD_SE(sva);
}
}
}
if (next_bucket > eva)
next_bucket = eva;
l2b = pmap_get_l2_bucket(pmap, sva);
if (l2b == NULL)
continue;
for (ptep = &l2b->l2b_kva[l2pte_index(sva)];
sva != next_bucket; ptep++, sva += PAGE_SIZE) {
opte = pte = *ptep;
if ((opte & L2_S_PROTO) == 0)
continue;
m = PHYS_TO_VM_PAGE(l2pte_pa(opte));
if (m == NULL || (m->oflags & VPO_UNMANAGED) != 0)
continue;
else if (L2_S_WRITABLE(opte)) {
if (advice == MADV_DONTNEED) {
/*
* Don't need to mark the page
* dirty as it was already marked as
* such in pmap_fault_fixup() or
* pmap_enter_locked().
* Just clear the state.
*/
} else
pte |= L2_APX;
pte &= ~L2_S_REF;
*ptep = pte;
PTE_SYNC(ptep);
} else if (L2_S_REFERENCED(opte)) {
pte &= ~L2_S_REF;
*ptep = pte;
PTE_SYNC(ptep);
} else
continue;
if (pmap_is_current(pmap)) {
if (PTE_BEEN_EXECD(opte))
cpu_tlb_flushID_SE(sva);
else if (PTE_BEEN_REFD(opte))
cpu_tlb_flushD_SE(sva);
}
}
}
rw_wunlock(&pvh_global_lock);
PMAP_UNLOCK(pmap);
}
/*