On Friday, April 01, 2016 01:07:55 PM Luigi Rizzo wrote: > On Thu, Mar 31, 2016 at 11:55 PM, Ryan Stone <[email protected]> wrote: > > > On Thu, Mar 31, 2016 at 4:39 PM, John Baldwin <[email protected]> wrote: > > > >> On Wednesday, March 30, 2016 11:20:51 AM Jim Harris wrote: > >> > On Wed, Mar 30, 2016 at 10:47 AM, Luigi Rizzo <[email protected]> > >> wrote: > >> > > >> > > Hi, > >> > > I'd like to test the rate at which I can access device registers > >> > > on a PCIe card, and was wondering whether I need to patch a device > >> > > driver, or perhaps I can use /dev/kmem once I figure out where > >> > > the registers are mapped ? > >> > > > >> > > >> > You do not need to patch a device driver. Have you looked at > >> > libpciaccess? This should give you everything you need. > >> > >> You can also look at what pciconf uses. (It has a read_config() method > >> that uses an ioctl on an fd of /dev/pci). > >> > > > > pciconf can only access the configuration space, right? I believe that > > Luigi is more interested in measuring the latency to a register mapped from > > a BAR. > > > > Thank you all for you answers, I will look at libpciaccess. > > Yes my goal is to look at the rate and latency for accessing > BAR-mapped registers
Sorry, I mapped PCIe registers to the PCI-e config space register set. I am not sure exactly how libpciaccess handles register access (perhaps it reads raw bars and maps them via /dev/mem)? However, it would not be hard to a new ioctl to /dev/pci to allow one to mmap a specific BAR of a given device. -- John Baldwin _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "[email protected]"
