Paul Burton wrote:
It is, however, used in such a way by others & seems to me like the only
correct way to implement the lazy cache flushing. The alternative would
be to adjust all generic code to ensure flush_icache_page gets called
before set_pte_at
... which is an exact case right now. Both calls of flush_icache_page() are:
1) do_swap_page()
flush_icache_page(vma, page);
if (pte_swp_soft_dirty(orig_pte))
pte = pte_mksoft_dirty(pte);
set_pte_at(mm, address, page_table, pte);
...
2) do_set_pte()
flush_icache_page(vma, page);
entry = mk_pte(page, vma->vm_page_prot);
if (write)
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
if (anon) {
inc_mm_counter_fast(vma->vm_mm, MM_ANONPAGES);
page_add_new_anon_rmap(page, vma, address);
} else {
inc_mm_counter_fast(vma->vm_mm, MM_FILEPAGES);
page_add_file_rmap(page);
}
set_pte_at(vma->vm_mm, address, pte, entry);
/* no need to invalidate: a not-present page won't be cached */
update_mmu_cache(vma, address, pte);
....
You should only be sure that flush_icache_page() completes a lazy
D-cache flush.
- Leonid.
