diff options
Diffstat (limited to 'sys/i386/xen/pmap.c')
-rw-r--r-- | sys/i386/xen/pmap.c | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/sys/i386/xen/pmap.c b/sys/i386/xen/pmap.c index c34fe29..3abe7ef 100644 --- a/sys/i386/xen/pmap.c +++ b/sys/i386/xen/pmap.c @@ -3914,6 +3914,72 @@ pmap_ts_referenced(vm_page_t m) } /* + * 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 and set the mapped page's dirty field. + */ +void +pmap_advise(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, int advice) +{ + pd_entry_t oldpde; + pt_entry_t *pte; + vm_offset_t pdnxt; + vm_page_t m; + boolean_t anychanged; + + if (advice != MADV_DONTNEED && advice != MADV_FREE) + return; + anychanged = FALSE; + rw_wlock(&pvh_global_lock); + sched_pin(); + PMAP_LOCK(pmap); + for (; sva < eva; sva = pdnxt) { + pdnxt = (sva + NBPDR) & ~PDRMASK; + if (pdnxt < sva) + pdnxt = eva; + oldpde = pmap->pm_pdir[sva >> PDRSHIFT]; + if ((oldpde & (PG_PS | PG_V)) != PG_V) + continue; + if (pdnxt > eva) + pdnxt = eva; + for (pte = pmap_pte_quick(pmap, sva); sva != pdnxt; pte++, + sva += PAGE_SIZE) { + if ((*pte & (PG_MANAGED | PG_V)) != (PG_MANAGED | + PG_V)) + continue; + else if ((*pte & (PG_M | PG_RW)) == (PG_M | PG_RW)) { + if (advice == MADV_DONTNEED) { + /* + * Future calls to pmap_is_modified() + * can be avoided by making the page + * dirty now. + */ + m = PHYS_TO_VM_PAGE(xpmap_mtop(*pte) & + PG_FRAME); + vm_page_dirty(m); + } + PT_SET_VA_MA(pte, *pte & ~(PG_M | PG_A), TRUE); + } else if ((*pte & PG_A) != 0) + PT_SET_VA_MA(pte, *pte & ~PG_A, TRUE); + else + continue; + if ((*pte & PG_G) != 0) + pmap_invalidate_page(pmap, sva); + else + anychanged = TRUE; + } + } + PT_UPDATES_FLUSH(); + if (*PMAP1) + PT_SET_VA_MA(PMAP1, 0, TRUE); + if (anychanged) + pmap_invalidate_all(pmap); + sched_unpin(); + rw_wunlock(&pvh_global_lock); + PMAP_UNLOCK(pmap); +} + +/* * Clear the modify bits on the specified physical page. */ void |