From: Hendrik Brueckner Date: Thu, 12 Dec 2013 15:52:48 +0000 (+0100) Subject: s390/perf,oprofile: Share sampling facility X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=e28bb79d9935293a8eea5f3c771fde89db645ba7;p=linux-beck.git s390/perf,oprofile: Share sampling facility Introduce reserve/release functions to share the sampling facility between perf and oprofile. Also improve error handling for the sampling facility support in perf. Signed-off-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky --- diff --git a/arch/s390/include/asm/perf_event.h b/arch/s390/include/asm/perf_event.h index b4eea25f379e..23d2dfa8201d 100644 --- a/arch/s390/include/asm/perf_event.h +++ b/arch/s390/include/asm/perf_event.h @@ -52,5 +52,9 @@ extern unsigned long perf_misc_flags(struct pt_regs *regs); #define TEAR_REG(hwc) ((hwc)->last_tag) #define SAMPL_RATE(hwc) ((hwc)->event_base) +/* Perf hardware reserve and release functions */ +int perf_reserve_sampling(void); +void perf_release_sampling(void); + #endif /* CONFIG_64BIT */ #endif /* _ASM_S390_PERF_EVENT_H */ diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c index 52bf36ee91aa..ae5e0192160d 100644 --- a/arch/s390/kernel/perf_cpum_sf.c +++ b/arch/s390/kernel/perf_cpum_sf.c @@ -260,16 +260,12 @@ static int sf_disable(void) #define PMC_INIT 0 #define PMC_RELEASE 1 +#define PMC_FAILURE 2 static void setup_pmc_cpu(void *flags) { int err; struct cpu_hw_sf *cpusf = &__get_cpu_var(cpu_hw_sf); - /* XXX Improve error handling and pass a flag in the *flags - * variable to indicate failures. Alternatively, ignore - * (print) errors here and let the PMU functions fail if - * the per-cpu PMU_F_RESERVED flag is not. - */ err = 0; switch (*((int *) flags)) { case PMC_INIT: @@ -299,6 +295,8 @@ static void setup_pmc_cpu(void *flags) "setup_pmc_cpu: released: cpuhw=%p\n", cpusf); break; } + if (err) + *((int *) flags) |= PMC_FAILURE; } static void release_pmc_hardware(void) @@ -307,13 +305,22 @@ static void release_pmc_hardware(void) irq_subclass_unregister(IRQ_SUBCLASS_MEASUREMENT_ALERT); on_each_cpu(setup_pmc_cpu, &flags, 1); + perf_release_sampling(); } static int reserve_pmc_hardware(void) { int flags = PMC_INIT; + int err; + err = perf_reserve_sampling(); + if (err) + return err; on_each_cpu(setup_pmc_cpu, &flags, 1); + if (flags & PMC_FAILURE) { + release_pmc_hardware(); + return -ENODEV; + } irq_subclass_register(IRQ_SUBCLASS_MEASUREMENT_ALERT); return 0; diff --git a/arch/s390/kernel/perf_event.c b/arch/s390/kernel/perf_event.c index b9843ba9829f..4edcdfa4894e 100644 --- a/arch/s390/kernel/perf_event.c +++ b/arch/s390/kernel/perf_event.c @@ -208,3 +208,33 @@ ssize_t cpumf_events_sysfs_show(struct device *dev, return sprintf(page, "event=0x%04llx,name=%s\n", pmu_attr->id, attr->attr.name); } + +/* Reserve/release functions for sharing perf hardware */ +static DEFINE_SPINLOCK(perf_hw_owner_lock); +static void *perf_sampling_owner; + +int perf_reserve_sampling(void) +{ + int err; + + err = 0; + spin_lock(&perf_hw_owner_lock); + if (perf_sampling_owner) { + pr_warn("The sampling facility is already reserved by %p\n", + perf_sampling_owner); + err = -EBUSY; + } else + perf_sampling_owner = __builtin_return_address(0); + spin_unlock(&perf_hw_owner_lock); + return err; +} +EXPORT_SYMBOL(perf_reserve_sampling); + +void perf_release_sampling(void) +{ + spin_lock(&perf_hw_owner_lock); + WARN_ON(!perf_sampling_owner); + perf_sampling_owner = NULL; + spin_unlock(&perf_hw_owner_lock); +} +EXPORT_SYMBOL(perf_release_sampling); diff --git a/arch/s390/oprofile/hwsampler.c b/arch/s390/oprofile/hwsampler.c index bbca76ad6e1b..eb095874540d 100644 --- a/arch/s390/oprofile/hwsampler.c +++ b/arch/s390/oprofile/hwsampler.c @@ -41,6 +41,7 @@ static DEFINE_MUTEX(hws_sem_oom); static unsigned char hws_flush_all; static unsigned int hws_oom; +static unsigned int hws_alert; static struct workqueue_struct *hws_wq; static unsigned int hws_state; @@ -182,6 +183,9 @@ static void hws_ext_handler(struct ext_code ext_code, if (!(param32 & CPU_MF_INT_SF_MASK)) return; + if (!hws_alert) + return; + inc_irq_stat(IRQEXT_CMS); atomic_xchg(&cb->ext_params, atomic_read(&cb->ext_params) | param32); @@ -941,6 +945,7 @@ int hwsampler_deallocate(void) goto deallocate_exit; irq_subclass_unregister(IRQ_SUBCLASS_MEASUREMENT_ALERT); + hws_alert = 0; deallocate_sdbt(); hws_state = HWS_DEALLOCATED; @@ -1055,6 +1060,7 @@ int hwsampler_shutdown(void) if (hws_state == HWS_STOPPED) { irq_subclass_unregister(IRQ_SUBCLASS_MEASUREMENT_ALERT); + hws_alert = 0; deallocate_sdbt(); } if (hws_wq) { @@ -1129,6 +1135,7 @@ start_all_exit: hws_oom = 1; hws_flush_all = 0; /* now let them in, 1407 CPUMF external interrupts */ + hws_alert = 1; irq_subclass_register(IRQ_SUBCLASS_MEASUREMENT_ALERT); return 0; diff --git a/arch/s390/oprofile/init.c b/arch/s390/oprofile/init.c index 04e1b6a85362..9ffe645d5989 100644 --- a/arch/s390/oprofile/init.c +++ b/arch/s390/oprofile/init.c @@ -10,6 +10,7 @@ */ #include +#include #include #include #include @@ -67,6 +68,21 @@ module_param_call(cpu_type, set_cpu_type, NULL, NULL, 0); MODULE_PARM_DESC(cpu_type, "Force legacy basic mode sampling" "(report cpu_type \"timer\""); +static int __oprofile_hwsampler_start(void) +{ + int retval; + + retval = hwsampler_allocate(oprofile_sdbt_blocks, oprofile_sdb_blocks); + if (retval) + return retval; + + retval = hwsampler_start_all(oprofile_hw_interval); + if (retval) + hwsampler_deallocate(); + + return retval; +} + static int oprofile_hwsampler_start(void) { int retval; @@ -76,13 +92,13 @@ static int oprofile_hwsampler_start(void) if (!hwsampler_running) return timer_ops.start(); - retval = hwsampler_allocate(oprofile_sdbt_blocks, oprofile_sdb_blocks); + retval = perf_reserve_sampling(); if (retval) return retval; - retval = hwsampler_start_all(oprofile_hw_interval); + retval = __oprofile_hwsampler_start(); if (retval) - hwsampler_deallocate(); + perf_release_sampling(); return retval; } @@ -96,6 +112,7 @@ static void oprofile_hwsampler_stop(void) hwsampler_stop_all(); hwsampler_deallocate(); + perf_release_sampling(); return; }