OBJ_INDEX_BITS
MAX(32, (ZS_MAX_PAGES_PER_ZSPAGE << PAGE_SHIFT >> OBJ_INDEX_BITS))
*zpdesc = pfn_zpdesc(obj >> OBJ_INDEX_BITS);
*zpdesc = pfn_zpdesc(obj >> OBJ_INDEX_BITS);
obj = zpdesc_pfn(zpdesc) << OBJ_INDEX_BITS;
#define OBJ_INDEX_MASK ((_AC(1, UL) << OBJ_INDEX_BITS) - 1)