On Mon, Jun 1, 2020 at 12:13 AM Vladimir Oltean <olte...@gmail.com> wrote: > On Mon, 1 Jun 2020 at 00:05, Andy Shevchenko <andy.shevche...@gmail.com> > wrote: > > On Sunday, May 31, 2020, Vladimir Oltean <olte...@gmail.com> wrote:
> >> Sometimes debugging a device is easiest using devmem on its register > >> map, and that can be seen with /proc/iomem. But some device drivers have > >> many memory regions. Take for example a networking switch. Its memory > >> map used to look like this in /proc/iomem: > >> > >> 1fc000000-1fc3fffff : pcie@1f0000000 > >> 1fc000000-1fc3fffff : 0000:00:00.5 > >> 1fc010000-1fc01ffff : sys > >> 1fc030000-1fc03ffff : rew > >> 1fc060000-1fc0603ff : s2 > >> 1fc070000-1fc0701ff : devcpu_gcb > >> 1fc080000-1fc0800ff : qs > >> 1fc090000-1fc0900cb : ptp > >> 1fc100000-1fc10ffff : port0 > >> 1fc110000-1fc11ffff : port1 > >> 1fc120000-1fc12ffff : port2 > >> 1fc130000-1fc13ffff : port3 > >> 1fc140000-1fc14ffff : port4 > >> 1fc150000-1fc15ffff : port5 > >> 1fc200000-1fc21ffff : qsys > >> 1fc280000-1fc28ffff : ana > >> > >> But after the patch in Fixes: was applied, the information is now > >> presented in a much more opaque way: > >> > >> 1fc000000-1fc3fffff : pcie@1f0000000 > >> 1fc000000-1fc3fffff : 0000:00:00.5 > >> 1fc010000-1fc01ffff : 0000:00:00.5 > >> 1fc030000-1fc03ffff : 0000:00:00.5 > >> 1fc060000-1fc0603ff : 0000:00:00.5 > >> 1fc070000-1fc0701ff : 0000:00:00.5 > >> 1fc080000-1fc0800ff : 0000:00:00.5 > >> 1fc090000-1fc0900cb : 0000:00:00.5 > >> 1fc100000-1fc10ffff : 0000:00:00.5 > >> 1fc110000-1fc11ffff : 0000:00:00.5 > >> 1fc120000-1fc12ffff : 0000:00:00.5 > >> 1fc130000-1fc13ffff : 0000:00:00.5 > >> 1fc140000-1fc14ffff : 0000:00:00.5 > >> 1fc150000-1fc15ffff : 0000:00:00.5 > >> 1fc200000-1fc21ffff : 0000:00:00.5 > >> 1fc280000-1fc28ffff : 0000:00:00.5 > >> > >> That patch made a fair comment that /proc/iomem might be confusing when > >> it shows resources without an associated device, but we can do better > >> than just hide the resource name altogether. Namely, we can print the > >> device name _and_ the resource name. Like this: > >> > >> 1fc000000-1fc3fffff : pcie@1f0000000 > >> 1fc000000-1fc3fffff : 0000:00:00.5 > >> 1fc010000-1fc01ffff : 0000:00:00.5 sys > >> 1fc030000-1fc03ffff : 0000:00:00.5 rew > >> 1fc060000-1fc0603ff : 0000:00:00.5 s2 > >> 1fc070000-1fc0701ff : 0000:00:00.5 devcpu_gcb > >> 1fc080000-1fc0800ff : 0000:00:00.5 qs > >> 1fc090000-1fc0900cb : 0000:00:00.5 ptp > >> 1fc100000-1fc10ffff : 0000:00:00.5 port0 > >> 1fc110000-1fc11ffff : 0000:00:00.5 port1 > >> 1fc120000-1fc12ffff : 0000:00:00.5 port2 > >> 1fc130000-1fc13ffff : 0000:00:00.5 port3 > >> 1fc140000-1fc14ffff : 0000:00:00.5 port4 > >> 1fc150000-1fc15ffff : 0000:00:00.5 port5 > >> 1fc200000-1fc21ffff : 0000:00:00.5 qsys > >> 1fc280000-1fc28ffff : 0000:00:00.5 ana > > All of this seems an ABI change. > Yes, indeed. What should I understand from your comment though? You effectively break an ABI. -- With Best Regards, Andy Shevchenko
