* Debian kernels as of 2.6.20 enable CONFIG_PARAVIRT, which redefines

* Debian kernels as of 2.6.20 enable CONFIG_PARAVIRT, which redefines
  several core kernel calls as redirects through a paravirt.ops table
  that's marked GPL-only.  This breaks all non-GPL modules that used
  those (previously generally exported) calls even indirectly.  Apply a
  hack to switch from spin_lock_irq to spin_lock_irqsave to avoid the
  paravirt redirection so that the module will build.