Hi Sergei,
On Mon, 1 Jun 2020 at 21:48, Sergei Shtylyov
<sergei.shtyl...@cogentembedded.com> wrote:
>
> On 06/01/2020 12:58 PM, Vladimir Oltean wrote:
>
> > From: Vladimir Oltean <vladimir.olt...@nxp.com>
> >
> > 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
> >
> > Fixes: 8d84b18f5678 ("devres: always use dev_name() in
> > devm_ioremap_resource()")
> > Signed-off-by: Vladimir Oltean <vladimir.olt...@nxp.com>
> > ---
> > Changes in v2:
> > Checking for memory allocation errors and returning -ENOMEM.
> >
> > Changes in v3:
> > Using devm_kasprintf instead of open-coding it.
> >
> > lib/devres.c | 11 ++++++++++-
> > 1 file changed, 10 insertions(+), 1 deletion(-)
> >
> > diff --git a/lib/devres.c b/lib/devres.c
> > index 6ef51f159c54..ca0d28727cce 100644
> > --- a/lib/devres.c
> > +++ b/lib/devres.c
> > @@ -119,6 +119,7 @@ __devm_ioremap_resource(struct device *dev, const
> > struct resource *res,
> > {
> > resource_size_t size;
> > void __iomem *dest_ptr;
> > + char *pretty_name;
> >
> > BUG_ON(!dev);
> >
> > @@ -129,7 +130,15 @@ __devm_ioremap_resource(struct device *dev, const
> > struct resource *res,
> >
> > size = resource_size(res);
> >
> > - if (!devm_request_mem_region(dev, res->start, size, dev_name(dev))) {
> > + if (res->name)
> > + pretty_name = devm_kasprintf(dev, GFP_KERNEL, "%s %s",
>
> What about "%s:%s"? I suspect it'd be better on the ABI side of things?
>
> [...]
>
> MBR, Sergei
I don't have a particular preference, but out of curiosity, why would
it be better?
Thanks,
-Vladimir
