On Mar 27, 2006, at 2:02 AM, Phil Nitschke wrote: > On Thu, 2006-03-23 at 09:44 -0600, Kumar Gala wrote: >> On Mar 23, 2006, at 8:21 AM, Wyse, Chris wrote: >> >>> Hi, >>> >>> I'm trying to map a PCI memory region 1 into user space from my >>> driver (PPC440GX, Linux 2.6.10). Here's the mmap routine of the >>> driver that I'm using: >> >> Why don't use the mmap file exposed by sysfs so you dont have to >> write your own code? >> >> See Documentation/filesystems/sysfs-pci.txt. But effectively down >> under /sys/bus/pci/devices/[domain:bus:dev:func]/ you will get >> resource[0..N-1] that corresponds to each BAR on the device. This is >> a mmap file to access that region. > > I have some custom hardware that appears on the PCI bus as follows: > > bash-3.00# lspci -vv > 00:01.0 Class 0680: 1172:0004 (rev 01) > Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- > Stepping- SERR- FastB2B- > Status: Cap- 66Mhz+ UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort+ > <TAbort- <MAbort- >SERR- <PERR- > Latency: 128, Cache Line Size 08 > Interrupt: pin A routed to IRQ 71 > Region 0: Memory at 000000009ffff000 (32-bit, non-prefetchable) > [size=4K] > Region 1: Memory at 000000009fc00000 (32-bit, non-prefetchable) > [size=2M] > > But when I try to access resource0 or resource1, I get a read error. > What characteristic of the device or driver determines whether it will > allow mmap-ing? > > (I've written the driver for this device myself.)
Nothing special beyond normal unix perms on the resource[0..n] files to my knowledge. When you say you get a read error what exactly does that mean? - kumar
