| Message ID | 20240126142324.66674-38-andrew.jones@linux.dev (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Introduce RISC-V | expand |
On 1/26/24 15:23, Andrew Jones wrote: > Remove spinlocks from on_cpu_async() by pulling some of their > use into a new function and also by narrowing the locking to a > single on_cpu_info structure by introducing yet another cpumask. > > Signed-off-by: Andrew Jones <andrew.jones@linux.dev> > Acked-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Eric > --- > lib/arm/asm/smp.h | 4 +++- > lib/arm/smp.c | 37 ++++++++++++++++++++++++++++--------- > 2 files changed, 31 insertions(+), 10 deletions(-) > > diff --git a/lib/arm/asm/smp.h b/lib/arm/asm/smp.h > index 9f6d839ab568..f0c0f97a19f8 100644 > --- a/lib/arm/asm/smp.h > +++ b/lib/arm/asm/smp.h > @@ -27,9 +27,11 @@ extern bool cpu0_calls_idle; > extern void halt(void); > extern void do_idle(void); > > -extern void smp_boot_secondary(int cpu, secondary_entry_fn entry); > extern void on_cpu_async(int cpu, void (*func)(void *data), void *data); > extern void on_cpu(int cpu, void (*func)(void *data), void *data); > extern void on_cpus(void (*func)(void *data), void *data); > > +extern void smp_boot_secondary(int cpu, secondary_entry_fn entry); > +extern void smp_boot_secondary_nofail(int cpu, secondary_entry_fn entry); > + > #endif /* _ASMARM_SMP_H_ */ > diff --git a/lib/arm/smp.c b/lib/arm/smp.c > index c00fda2efb03..e0872a1a72c2 100644 > --- a/lib/arm/smp.c > +++ b/lib/arm/smp.c > @@ -76,12 +76,32 @@ void smp_boot_secondary(int cpu, secondary_entry_fn entry) > spin_unlock(&lock); > } > > +void smp_boot_secondary_nofail(int cpu, secondary_entry_fn entry) > +{ > + spin_lock(&lock); > + if (!cpu_online(cpu)) > + __smp_boot_secondary(cpu, entry); > + spin_unlock(&lock); > +} > + > struct on_cpu_info { > void (*func)(void *data); > void *data; > cpumask_t waiters; > }; > static struct on_cpu_info on_cpu_info[NR_CPUS]; > +static cpumask_t on_cpu_info_lock; > + > +static bool get_on_cpu_info(int cpu) > +{ > + return !cpumask_test_and_set_cpu(cpu, &on_cpu_info_lock); > +} > + > +static void put_on_cpu_info(int cpu) > +{ > + int ret = cpumask_test_and_clear_cpu(cpu, &on_cpu_info_lock); > + assert(ret); > +} > > static void __deadlock_check(int cpu, const cpumask_t *waiters, bool *found) > { > @@ -158,22 +178,21 @@ void on_cpu_async(int cpu, void (*func)(void *data), void *data) > assert_msg(cpu != 0 || cpu0_calls_idle, "Waiting on CPU0, which is unlikely to idle. " > "If this is intended set cpu0_calls_idle=1"); > > - spin_lock(&lock); > - if (!cpu_online(cpu)) > - __smp_boot_secondary(cpu, do_idle); > - spin_unlock(&lock); > + smp_boot_secondary_nofail(cpu, do_idle); > > for (;;) { > cpu_wait(cpu); > - spin_lock(&lock); > - if ((volatile void *)on_cpu_info[cpu].func == NULL) > - break; > - spin_unlock(&lock); > + if (get_on_cpu_info(cpu)) { > + if ((volatile void *)on_cpu_info[cpu].func == NULL) > + break; > + put_on_cpu_info(cpu); > + } > } > + > on_cpu_info[cpu].func = func; > on_cpu_info[cpu].data = data; > - spin_unlock(&lock); > set_cpu_idle(cpu, false); > + put_on_cpu_info(cpu); > smp_send_event(); > } >
diff --git a/lib/arm/asm/smp.h b/lib/arm/asm/smp.h index 9f6d839ab568..f0c0f97a19f8 100644 --- a/lib/arm/asm/smp.h +++ b/lib/arm/asm/smp.h @@ -27,9 +27,11 @@ extern bool cpu0_calls_idle; extern void halt(void); extern void do_idle(void); -extern void smp_boot_secondary(int cpu, secondary_entry_fn entry); extern void on_cpu_async(int cpu, void (*func)(void *data), void *data); extern void on_cpu(int cpu, void (*func)(void *data), void *data); extern void on_cpus(void (*func)(void *data), void *data); +extern void smp_boot_secondary(int cpu, secondary_entry_fn entry); +extern void smp_boot_secondary_nofail(int cpu, secondary_entry_fn entry); + #endif /* _ASMARM_SMP_H_ */ diff --git a/lib/arm/smp.c b/lib/arm/smp.c index c00fda2efb03..e0872a1a72c2 100644 --- a/lib/arm/smp.c +++ b/lib/arm/smp.c @@ -76,12 +76,32 @@ void smp_boot_secondary(int cpu, secondary_entry_fn entry) spin_unlock(&lock); } +void smp_boot_secondary_nofail(int cpu, secondary_entry_fn entry) +{ + spin_lock(&lock); + if (!cpu_online(cpu)) + __smp_boot_secondary(cpu, entry); + spin_unlock(&lock); +} + struct on_cpu_info { void (*func)(void *data); void *data; cpumask_t waiters; }; static struct on_cpu_info on_cpu_info[NR_CPUS]; +static cpumask_t on_cpu_info_lock; + +static bool get_on_cpu_info(int cpu) +{ + return !cpumask_test_and_set_cpu(cpu, &on_cpu_info_lock); +} + +static void put_on_cpu_info(int cpu) +{ + int ret = cpumask_test_and_clear_cpu(cpu, &on_cpu_info_lock); + assert(ret); +} static void __deadlock_check(int cpu, const cpumask_t *waiters, bool *found) { @@ -158,22 +178,21 @@ void on_cpu_async(int cpu, void (*func)(void *data), void *data) assert_msg(cpu != 0 || cpu0_calls_idle, "Waiting on CPU0, which is unlikely to idle. " "If this is intended set cpu0_calls_idle=1"); - spin_lock(&lock); - if (!cpu_online(cpu)) - __smp_boot_secondary(cpu, do_idle); - spin_unlock(&lock); + smp_boot_secondary_nofail(cpu, do_idle); for (;;) { cpu_wait(cpu); - spin_lock(&lock); - if ((volatile void *)on_cpu_info[cpu].func == NULL) - break; - spin_unlock(&lock); + if (get_on_cpu_info(cpu)) { + if ((volatile void *)on_cpu_info[cpu].func == NULL) + break; + put_on_cpu_info(cpu); + } } + on_cpu_info[cpu].func = func; on_cpu_info[cpu].data = data; - spin_unlock(&lock); set_cpu_idle(cpu, false); + put_on_cpu_info(cpu); smp_send_event(); }