This patch has been tested on the raspberry pi 2/3 boards with 4.6.y kernel. Another patch written for dwc_otg driver (not in mainline) that uses the features provided by this patch. it's available here https://www.osadl.org/monitoring/patches/r7s3s/0002-usb-dwc_otg-enable-fiq-stat.patch To see both patches in action, you may viewed it on OSALD QA Farm here: https://www.osadl.org/Profile-of-system-in-rack-7-slot-3.qa-profile-r7s3.0.html?shadow=1
Oussama On Tue, Nov 29, 2016 at 11:48 PM, Oussama Ghorbel <[email protected]> wrote: > This patch allows drivers that uses fiq to have a stat on the > execution number of the fiq handler. > For that three APIs has been defined: > - fiq_kstat_enable: this function enables fiq stat and allocates required > memory for it > - fiq_kstat_disable: this function disable fiq stat and free its allocated > memory > - fiq_kstat_this_cpu_inc: This function increments the fiq stat counter of > the current CPU running the fiq handler > > A driver may call fiq_kstat_enable at its initialization to enable fiq > stat and then call fiq_kstat_this_cpu_inc from the fiq handler > > When the fiq stat is enabled by a driver, then /proc/interrupts shows the > fiq entry as the following example: > FIQ: 0 21642080 0 0 usb_fiq > If the fiq stat is not enabled, the content will be similar to the old one > as the following example: > FIQ: usb_fiq > The fiq name will be always written on the first column after the last CPU > column > > Signed-off-by: Oussama Ghorbel <[email protected]> > --- > arch/arm/include/asm/fiq.h | 10 ++++++++++ > arch/arm/kernel/fiq.c | 31 +++++++++++++++++++++++++++---- > 2 files changed, 37 insertions(+), 4 deletions(-) > > diff --git a/arch/arm/include/asm/fiq.h b/arch/arm/include/asm/fiq.h > index d493d0b..77f819b 100644 > --- a/arch/arm/include/asm/fiq.h > +++ b/arch/arm/include/asm/fiq.h > @@ -31,6 +31,8 @@ struct fiq_handler { > /* data for the relinquish/reacquire functions > */ > void *dev_id; > + /* fiq stats percpu */ > + unsigned int __percpu *fiq_kstat; > }; > > extern int claim_fiq(struct fiq_handler *f); > @@ -53,4 +55,12 @@ static inline void get_fiq_regs(struct pt_regs *regs) > __get_fiq_regs(®s->ARM_r8); > } > > +extern int fiq_kstat_enable(struct fiq_handler *fh); > +extern void fiq_kstat_disable(struct fiq_handler *fh); > + > +static inline void fiq_kstat_this_cpu_inc(struct fiq_handler *fh) > +{ > + __this_cpu_inc(*fh->fiq_kstat); > +} > + > #endif > diff --git a/arch/arm/kernel/fiq.c b/arch/arm/kernel/fiq.c > index 059c3da..4b606df 100644 > --- a/arch/arm/kernel/fiq.c > +++ b/arch/arm/kernel/fiq.c > @@ -83,10 +83,19 @@ static struct fiq_handler *current_fiq = &default_owner; > > int show_fiq_list(struct seq_file *p, int prec) > { > - if (current_fiq != &default_owner) > - seq_printf(p, "%*s: %s\n", prec, "FIQ", > - current_fiq->name); > - > + int j; > + > + if (current_fiq == &default_owner) > + return 0; > + seq_printf(p, "%*s: ", prec, "FIQ"); > + for_each_online_cpu(j) { > + if (current_fiq->fiq_kstat) > + seq_printf(p, "%10u ", > + *per_cpu_ptr(current_fiq->fiq_kstat, j)); > + else > + seq_printf(p, "%10s ", ""); > + } > + seq_printf(p, " %s\n", current_fiq->name); > return 0; > } > > @@ -162,3 +171,17 @@ void __init init_FIQ(int start) > get_fiq_regs(&dfl_fiq_regs); > fiq_start = start; > } > + > +int fiq_kstat_enable(struct fiq_handler *fh) > +{ > + fh->fiq_kstat = alloc_percpu(unsigned int); > + return fh->fiq_kstat != 0 ? 0 : 1; > +} > +EXPORT_SYMBOL(fiq_kstat_enable); > + > +void fiq_kstat_disable(struct fiq_handler *fh) > +{ > + free_percpu(fh->fiq_kstat); > + fh->fiq_kstat = NULL; > +} > +EXPORT_SYMBOL(fiq_kstat_disable); > -- > 2.7.4 >
