Hi, Josh: I have resolved my kernel driver problem, it was my own bug, didn't have anything to do with memory remapping itself. Your suggestion to move to ioremap64() did resolve problem completely.
I still need investigate mmap() crash. Apparently switch to mmap64() didn't help, but it could be some another bug, I'll double check. Thanks, Leonid. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Leonid Sent: Tuesday, April 01, 2008 9:30 PM To: Josh Boyer Cc: linuxppc-embedded@ozlabs.org Subject: RE: Access physical memory via mmap() on ppc440epx. Hi, Josh: Thank you for your suggestion. Somehow it didn't work with mmap (may be, my mistake, I'll double check), however it partially helped me with my another problem. I have kernel driver where I need read/write some HW device, connected on address 0xea000000, chip select 4. This chip select configured properly, here are EBC registers: 440EPx>rd ebc0_b4cr ebc0_b4cr: 0xea01a000 -368992256 440EPx>rd ebc0_b4ap ebc0_b4ap: 0x03037000 50556928 >From u-boot I can read/write this address with no problem (I use md/mw commands). In my driver I tried to ioremap() this address and any attempt to access led to crash, same as with mmap(). When, following your suggestion, I used address 0x1ea00000 and ioremap64(), crashes disappeared! I even can write, but when I read data back I see least significant byte of each 16 bits word only (bus is configured 16 bits width). What can it be? Thanks, Leonid. -----Original Message----- From: Josh Boyer [mailto:[EMAIL PROTECTED] Sent: Tuesday, April 01, 2008 6:44 PM To: Leonid Cc: linuxppc-embedded@ozlabs.org Subject: Re: Access physical memory via mmap() on ppc440epx. On Tue, 2008-04-01 at 14:12 -0700, Leonid wrote: > Hi: > > I am trying to read from NOR flash, located on address 0xfc000000, on my It's at 0x1fc000000 IIRC. > TLB entries look strange though. That what it was on u-boot stage: > > 440EPx>tlb 0 10 > IDX TID EPN SIZE VTS RPN USER WIMGE USRSVC > 0 : 00 40000000 256MB V0 -> 0_00000000 U:0000 -I-G- XWRXWR > 1 : 00 00000000 256MB V0 -> 0_00000000 U:0000 -I-G- XWRXWR > 2 : 00 c0000000 256MB V0 -> 1_c0000000 U:0000 -I-G- XWRXWR > 3 : 00 f0000000 256MB V0 -> 1_f0000000 U:0000 WI-G- XWRXWR See. Virtual is 0xf0000000, physical is 0x1f0000000. > On Linux stage it looks rather different: I don't even see your entry in here. Likely because the TLB is small and it's gone by the time you do the dump > Probably under MMU it should look this way? How to use mmap() then? Try mmap64 on the real physical address and see if that helps. josh _______________________________________________ Linuxppc-embedded mailing list Linuxppc-embedded@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-embedded _______________________________________________ Linuxppc-embedded mailing list Linuxppc-embedded@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-embedded
