On Mar 11, 2010, at 6:40 PM, nathan binkert wrote: >> According to the OpenVMS chapter of the Alpha Manual, IPL 31 is >> machine >> check errors, which is baffling. I am curious to why their "seems" >> to be so >> many of these IPL changes to this level. It doesnt sound right if >> IPL 31 >> correspond to machine check errors, I am wondering if this is >> incorrect. And >> exploring that their is a possible cross compiler bug. > > There are two different IPLs. There's the IPL in the CPU and one > that's in the platform. I believe that the IPL 31 is the platform IPL > whereas the mchk that you're talking about is the CPU IPL.
The IPL gets changed around (local_irq_disable(), local_irq_save()): http://lxr.linux.no/linux+v2.6.33/arch/alpha/include/asm/system.h#L282 Which choses a software IPL level between 0 and 7. That value gets changed to a CPU specific IPL in the palcode here: http://repo.m5sim.org/alpha-system/file/54e0019e3b94/palcode/osfpal.S#l3011 by doing extracting the proper byte from the pt_intmask register that is created here: http://repo.m5sim.org/alpha-system/file/54e0019e3b94/palcode/platform.S#l1448 IPL_MAX in linux (7) corresponds to IPL 0x1f for the CPU. Ali _______________________________________________ m5-users mailing list [email protected] http://m5sim.org/cgi-bin/mailman/listinfo/m5-users
