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Index: head/sys/riscv/riscv/pmap.c
===================================================================
--- head/sys/riscv/riscv/pmap.c
+++ head/sys/riscv/riscv/pmap.c
@@ -4074,6 +4074,14 @@
void
pmap_clear_modify(vm_page_t m)
{
+ struct md_page *pvh;
+ struct rwlock *lock;
+ pmap_t pmap;
+ pv_entry_t next_pv, pv;
+ pd_entry_t *l2, oldl2;
+ pt_entry_t *l3, oldl3;
+ vm_offset_t va;
+ int md_gen, pvh_gen;
KASSERT((m->oflags & VPO_UNMANAGED) == 0,
("pmap_clear_modify: page %p is not managed", m));
@@ -4088,8 +4096,78 @@
*/
if ((m->aflags & PGA_WRITEABLE) == 0)
return;
-
- /* RISCVTODO: We lack support for tracking if a page is modified */
+ pvh = (m->flags & PG_FICTITIOUS) != 0 ? &pv_dummy :
+ pa_to_pvh(VM_PAGE_TO_PHYS(m));
+ lock = VM_PAGE_TO_PV_LIST_LOCK(m);
+ rw_rlock(&pvh_global_lock);
+ rw_wlock(lock);
+restart:
+ TAILQ_FOREACH_SAFE(pv, &pvh->pv_list, pv_next, next_pv) {
+ pmap = PV_PMAP(pv);
+ if (!PMAP_TRYLOCK(pmap)) {
+ pvh_gen = pvh->pv_gen;
+ rw_wunlock(lock);
+ PMAP_LOCK(pmap);
+ rw_wlock(lock);
+ if (pvh_gen != pvh->pv_gen) {
+ PMAP_UNLOCK(pmap);
+ goto restart;
+ }
+ }
+ va = pv->pv_va;
+ l2 = pmap_l2(pmap, va);
+ oldl2 = pmap_load(l2);
+ if ((oldl2 & PTE_W) != 0) {
+ if (pmap_demote_l2_locked(pmap, l2, va, &lock)) {
+ if ((oldl2 & PTE_SW_WIRED) == 0) {
+ /*
+ * Write protect the mapping to a
+ * single page so that a subsequent
+ * write access may repromote.
+ */
+ va += VM_PAGE_TO_PHYS(m) -
+ PTE_TO_PHYS(oldl2);
+ l3 = pmap_l2_to_l3(l2, va);
+ oldl3 = pmap_load(l3);
+ if ((oldl3 & PTE_V) != 0) {
+ while (!atomic_fcmpset_long(l3,
+ &oldl3, oldl3 & ~(PTE_D |
+ PTE_W)))
+ cpu_spinwait();
+ vm_page_dirty(m);
+ pmap_invalidate_page(pmap, va);
+ }
+ }
+ }
+ }
+ PMAP_UNLOCK(pmap);
+ }
+ TAILQ_FOREACH(pv, &m->md.pv_list, pv_next) {
+ pmap = PV_PMAP(pv);
+ if (!PMAP_TRYLOCK(pmap)) {
+ md_gen = m->md.pv_gen;
+ pvh_gen = pvh->pv_gen;
+ rw_wunlock(lock);
+ PMAP_LOCK(pmap);
+ rw_wlock(lock);
+ if (pvh_gen != pvh->pv_gen || md_gen != m->md.pv_gen) {
+ PMAP_UNLOCK(pmap);
+ goto restart;
+ }
+ }
+ l2 = pmap_l2(pmap, pv->pv_va);
+ KASSERT((pmap_load(l2) & PTE_RWX) == 0,
+ ("pmap_clear_modify: found a 2mpage in page %p's pv list",
+ m));
+ l3 = pmap_l2_to_l3(l2, pv->pv_va);
+ if ((pmap_load(l3) & (PTE_D | PTE_W)) == (PTE_D | PTE_W)) {
+ pmap_clear_bits(l3, PTE_D);
+ pmap_invalidate_page(pmap, pv->pv_va);
+ }
+ PMAP_UNLOCK(pmap);
+ }
+ rw_wunlock(lock);
+ rw_runlock(&pvh_global_lock);
}
void *

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