Author: alc Date: Tue Jul 2 23:02:52 2019 New Revision: 349618 URL: https://svnweb.freebsd.org/changeset/base/349618
Log: Implement pmap_copy(). (This includes the changes applied to the amd64 pmap_copy() in r349585.) Reviewed by: kib, markj Differential Revision: https://reviews.freebsd.org/D20790 Modified: head/sys/arm64/arm64/pmap.c Modified: head/sys/arm64/arm64/pmap.c ============================================================================== --- head/sys/arm64/arm64/pmap.c Tue Jul 2 22:58:21 2019 (r349617) +++ head/sys/arm64/arm64/pmap.c Tue Jul 2 23:02:52 2019 (r349618) @@ -3875,12 +3875,153 @@ pmap_unwire(pmap_t pmap, vm_offset_t sva, vm_offset_t * in the destination map. * * This routine is only advisory and need not do anything. + * + * Because the executable mappings created by this routine are copied, + * it should not have to flush the instruction cache. */ - void pmap_copy(pmap_t dst_pmap, pmap_t src_pmap, vm_offset_t dst_addr, vm_size_t len, vm_offset_t src_addr) { + struct rwlock *lock; + struct spglist free; + pd_entry_t *l0, *l1, *l2, srcptepaddr; + pt_entry_t *dst_pte, ptetemp, *src_pte; + vm_offset_t addr, end_addr, va_next; + vm_page_t dst_l2pg, dstmpte, srcmpte; + + if (dst_addr != src_addr) + return; + end_addr = src_addr + len; + lock = NULL; + if (dst_pmap < src_pmap) { + PMAP_LOCK(dst_pmap); + PMAP_LOCK(src_pmap); + } else { + PMAP_LOCK(src_pmap); + PMAP_LOCK(dst_pmap); + } + for (addr = src_addr; addr < end_addr; addr = va_next) { + l0 = pmap_l0(src_pmap, addr); + if (pmap_load(l0) == 0) { + va_next = (addr + L0_SIZE) & ~L0_OFFSET; + if (va_next < addr) + va_next = end_addr; + continue; + } + l1 = pmap_l0_to_l1(l0, addr); + if (pmap_load(l1) == 0) { + va_next = (addr + L1_SIZE) & ~L1_OFFSET; + if (va_next < addr) + va_next = end_addr; + continue; + } + va_next = (addr + L2_SIZE) & ~L2_OFFSET; + if (va_next < addr) + va_next = end_addr; + l2 = pmap_l1_to_l2(l1, addr); + srcptepaddr = pmap_load(l2); + if (srcptepaddr == 0) + continue; + if ((srcptepaddr & ATTR_DESCR_MASK) == L2_BLOCK) { + if ((addr & L2_OFFSET) != 0 || + addr + L2_SIZE > end_addr) + continue; + dst_l2pg = pmap_alloc_l2(dst_pmap, addr, NULL); + if (dst_l2pg == NULL) + break; + l2 = (pd_entry_t *) + PHYS_TO_DMAP(VM_PAGE_TO_PHYS(dst_l2pg)); + l2 = &l2[pmap_l2_index(addr)]; + if (pmap_load(l2) == 0 && + ((srcptepaddr & ATTR_SW_MANAGED) == 0 || + pmap_pv_insert_l2(dst_pmap, addr, srcptepaddr, + PMAP_ENTER_NORECLAIM, &lock))) { + (void)pmap_load_store(l2, srcptepaddr & + ~ATTR_SW_WIRED); + pmap_resident_count_inc(dst_pmap, L2_SIZE / + PAGE_SIZE); + atomic_add_long(&pmap_l2_mappings, 1); + } else + dst_l2pg->wire_count--; + continue; + } + KASSERT((srcptepaddr & ATTR_DESCR_MASK) == L2_TABLE, + ("pmap_copy: invalid L2 entry")); + srcptepaddr &= ~ATTR_MASK; + srcmpte = PHYS_TO_VM_PAGE(srcptepaddr); + KASSERT(srcmpte->wire_count > 0, + ("pmap_copy: source page table page is unused")); + if (va_next > end_addr) + va_next = end_addr; + src_pte = (pt_entry_t *)PHYS_TO_DMAP(srcptepaddr); + src_pte = &src_pte[pmap_l3_index(addr)]; + dstmpte = NULL; + for (; addr < va_next; addr += PAGE_SIZE, src_pte++) { + ptetemp = pmap_load(src_pte); + + /* + * We only virtual copy managed pages. + */ + if ((ptetemp & ATTR_SW_MANAGED) == 0) + continue; + + if (dstmpte != NULL) { + KASSERT(dstmpte->pindex == pmap_l2_pindex(addr), + ("dstmpte pindex/addr mismatch")); + dstmpte->wire_count++; + } else if ((dstmpte = pmap_alloc_l3(dst_pmap, addr, + NULL)) == NULL) + goto out; + dst_pte = (pt_entry_t *) + PHYS_TO_DMAP(VM_PAGE_TO_PHYS(dstmpte)); + dst_pte = &dst_pte[pmap_l3_index(addr)]; + if (pmap_load(dst_pte) == 0 && + pmap_try_insert_pv_entry(dst_pmap, addr, + PHYS_TO_VM_PAGE(ptetemp & ~ATTR_MASK), &lock)) { + /* + * Clear the wired, modified, and accessed + * (referenced) bits during the copy. + * + * XXX not yet + */ + (void)pmap_load_store(dst_pte, ptetemp & + ~ATTR_SW_WIRED); + pmap_resident_count_inc(dst_pmap, 1); + } else { + SLIST_INIT(&free); + if (pmap_unwire_l3(dst_pmap, addr, dstmpte, + &free)) { + /* + * Although "addr" is not mapped, + * paging-structure caches could + * nonetheless have entries that refer + * to the freed page table pages. + * Invalidate those entries. + * + * XXX redundant invalidation + */ + pmap_invalidate_page(dst_pmap, addr); + vm_page_free_pages_toq(&free, true); + } + goto out; + } + /* Have we copied all of the valid mappings? */ + if (dstmpte->wire_count >= srcmpte->wire_count) + break; + } + } +out: + /* + * XXX This barrier may not be needed because the destination pmap is + * not active. + */ + dsb(ishst); + + if (lock != NULL) + rw_wunlock(lock); + PMAP_UNLOCK(src_pmap); + PMAP_UNLOCK(dst_pmap); } /* _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
