On 06/01/2020 11:03 PM, Vladimir Oltean wrote:
> 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?
No space amidst the name.
> Thanks,
> -Vladimir
MBR, Sergei
