On Fri, Aug 03, 2018 at 07:58:44PM +0530, Sai Prakash Ranjan wrote: > Introduce dynamic debug filtering mechanism to register > tracing as dynamic_rtb() which will reduce a lot of > overhead otherwise of tracing all the register reads/writes > in all files. > > Now we can just specify the file name or any wildcard pattern > as any other dynamic debug facility in bootargs and dynamic rtb > will just trace them and the output can be seen in pstore. > > TODO: Now we use same 'p' flag but will add a separate flag for register trace > later. > > Example for tracing all register reads/writes in drivers/soc/qcom/* below: > > # dyndbg="file drivers/soc/qcom/* +p" in bootargs > # reboot -f > # mount -t pstore pstore /sys/fs/pstore > # cat /sys/fs/pstore/rtb-ramoops-0 > [LOGK_WRITEL ] ts:1373030419 data:ffff00000d5065a4 <ffff00000867cb44> > qcom_smsm_probe+0x51c/0x668 > [LOGK_WRITEL ] ts:1373360576 data:ffff00000d506608 <ffff00000867cb44> > qcom_smsm_probe+0x51c/0x668 > > Also we add uncached_logk api to readl/writel definitions for arm64 > as of now. This can be extended to arm as well later for tracing. > > Signed-off-by: Sai Prakash Ranjan <saiprakash.ran...@codeaurora.org> > --- > arch/arm64/include/asm/io.h | 93 +++++++++++++++++++++++++++++++++++
Putting all of this in the arch code, which basically duplicates everything, feels very wrong to me. Perhaps take a look at the ongoing work for instrumenting the atomics and take some inspiration from there? Ideally, the architecture just needs to provide the low-level primivites (which it already does) and the core can generate instruments versions if required. Will
