CPU_DESC_FIELD
value = CPU_DESC_FIELD(user_cpu_desc, i);
value = CPU_DESC_FIELD(l_user_cpu_desc, i);
*val = CPU_DESC_FIELD(kern_cpu_desc, i);
val = CPU_DESC_FIELD(kern_cpu_desc, i);
*val = CPU_DESC_FIELD(user_cpu_desc, i);
*val = CPU_DESC_FIELD(l_user_cpu_desc, i);
k_old = CPU_DESC_FIELD(kern_cpu_desc, idx);
f_old = CPU_DESC_FIELD(user_cpu_desc, idx);
l_old = CPU_DESC_FIELD(l_user_cpu_desc, idx);
CPU_DESC_FIELD(kern_cpu_desc, idx) = k_new;
CPU_DESC_FIELD(user_cpu_desc, idx) = f_new;
CPU_DESC_FIELD(l_user_cpu_desc, idx) = l_new;
value = CPU_DESC_FIELD(*desc, i);
CPU_DESC_FIELD(kern_cpu_desc, i) = value;
CPU_DESC_FIELD(user_cpu_desc, i) = value;
CPU_DESC_FIELD(l_user_cpu_desc, i) = value;
reg = CPU_DESC_FIELD(*cpu_desc, i);