| Message ID | 20111117112841.9191.97974.stgit@localhost6.localdomain6 (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Benjamin Herrenschmidt |
| Headers | show |
On Thu, 2011-11-17 at 16:58 +0530, Deepthi Dharwar wrote: > This patch implements a backhand cpuidle driver for pSeries > based on pseries_dedicated_idle_loop and pseries_shared_idle_loop > routines. The driver is built only if CONFIG_CPU_IDLE is set. This > cpuidle driver uses global registration of idle states and > not per-cpu. .../... > +#define MAX_IDLE_STATE_COUNT 2 > + > +static int max_cstate = MAX_IDLE_STATE_COUNT - 1; Why "cstate" ? This isn't an x86 :-) > +static struct cpuidle_device __percpu *pseries_idle_cpuidle_devices; Shorter name please. pseries_cpuidle_devs is fine. > +static struct cpuidle_state *cpuidle_state_table; > + > +void update_smt_snooze_delay(int snooze) > +{ > + struct cpuidle_driver *drv = cpuidle_get_driver(); > + if (drv) > + drv->states[0].target_residency = snooze; > +} > + > +static inline void idle_loop_prolog(unsigned long *in_purr, ktime_t *kt_before) > +{ > + > + *kt_before = ktime_get_real(); > + *in_purr = mfspr(SPRN_PURR); > + /* > + * Indicate to the HV that we are idle. Now would be > + * a good time to find other work to dispatch. > + */ > + get_lppaca()->idle = 1; > + get_lppaca()->donate_dedicated_cpu = 1; > +} I notice that you call this on shared processors as well. The old ocde used to not set donate_dedicated_cpu in that case. I assume that's not a big deal and that the HV will just ignore it in the shared processor case but please add a comment after you've verified it. > +static inline s64 idle_loop_epilog(unsigned long in_purr, ktime_t kt_before) > +{ > + get_lppaca()->wait_state_cycles += mfspr(SPRN_PURR) - in_purr; > + get_lppaca()->donate_dedicated_cpu = 0; > + get_lppaca()->idle = 0; > + > + return ktime_to_us(ktime_sub(ktime_get_real(), kt_before)); > +} > + > + > +static int snooze_loop(struct cpuidle_device *dev, > + struct cpuidle_driver *drv, > + int index) > +{ > + unsigned long in_purr; > + ktime_t kt_before; > + > + idle_loop_prolog(&in_purr, &kt_before); > + > + local_irq_enable(); > + set_thread_flag(TIF_POLLING_NRFLAG); > + while (!need_resched()) { > + ppc64_runlatch_off(); > + HMT_low(); > + HMT_very_low(); > + } > + HMT_medium(); > + clear_thread_flag(TIF_POLLING_NRFLAG); > + smp_mb(); > + local_irq_disable(); > + > + dev->last_residency = > + (int)idle_loop_epilog(in_purr, kt_before); > + return index; > +} So your snooze loop has no timeout, is that handled by the cpuidle driver using some kind of timer ? That sounds a lot less efficient than passing a max delay to the snooze loop to handle getting into a deeper state after a bit of snoozing rather than interrupting etc... > +static int dedicated_cede_loop(struct cpuidle_device *dev, > + struct cpuidle_driver *drv, > + int index) > +{ > + unsigned long in_purr; > + ktime_t kt_before; > + > + idle_loop_prolog(&in_purr, &kt_before); > + > + ppc64_runlatch_off(); > + HMT_medium(); > + cede_processor(); > + > + dev->last_residency = > + (int)idle_loop_epilog(in_purr, kt_before); > + return index; > +} > + > +static int shared_cede_loop(struct cpuidle_device *dev, > + struct cpuidle_driver *drv, > + int index) > +{ > + unsigned long in_purr; > + ktime_t kt_before; > + > + idle_loop_prolog(&in_purr, &kt_before); > + > + /* > + * Yield the processor to the hypervisor. We return if > + * an external interrupt occurs (which are driven prior > + * to returning here) or if a prod occurs from another > + * processor. When returning here, external interrupts > + * are enabled. > + */ > + cede_processor(); > + > + dev->last_residency = > + (int)idle_loop_epilog(in_purr, kt_before); > + return index; > +} > + > +/* > + * States for dedicated partition case. > + */ > +static struct cpuidle_state dedicated_states[MAX_IDLE_STATE_COUNT] = { > + { /* Snooze */ > + .name = "snooze", > + .desc = "snooze", > + .flags = CPUIDLE_FLAG_TIME_VALID, > + .exit_latency = 0, > + .target_residency = 0, > + .enter = &snooze_loop }, > + { /* CEDE */ > + .name = "CEDE", > + .desc = "CEDE", > + .flags = CPUIDLE_FLAG_TIME_VALID, > + .exit_latency = 1, > + .target_residency = 10, > + .enter = &dedicated_cede_loop }, > +}; > + > +/* > + * States for shared partition case. > + */ > +static struct cpuidle_state shared_states[MAX_IDLE_STATE_COUNT] = { > + { /* Shared Cede */ > + .name = "Shared Cede", > + .desc = "Shared Cede", > + .flags = CPUIDLE_FLAG_TIME_VALID, > + .exit_latency = 0, > + .target_residency = 0, > + .enter = &shared_cede_loop }, > +}; > + > +int pseries_notify_cpuidle_add_cpu(int cpu) > +{ > + struct cpuidle_device *dev = > + per_cpu_ptr(pseries_idle_cpuidle_devices, cpu); > + if (dev && cpuidle_get_driver()) { > + cpuidle_disable_device(dev); > + cpuidle_enable_device(dev); > + } > + return 0; > +} > + > +/* > + * pseries_idle_cpuidle_driver_init() > + */ > +static int pseries_idle_cpuidle_driver_init(void) > +{ Drop the "idle", those names are too long. > + int cstate; And use something else than 'cstate', we are among civilized people here ;-) > + struct cpuidle_driver *drv = &pseries_idle_driver; > + > + drv->state_count = 0; > + > + for (cstate = 0; cstate < MAX_IDLE_STATE_COUNT; ++cstate) { > + > + if (cstate > max_cstate) > + break; > + > + /* is the state not enabled? */ > + if (cpuidle_state_table[cstate].enter == NULL) > + continue; > + > + drv->states[drv->state_count] = /* structure copy */ > + cpuidle_state_table[cstate]; > + > + if (cpuidle_state_table == dedicated_states) > + drv->states[drv->state_count].target_residency = > + __get_cpu_var(smt_snooze_delay); > + > + drv->state_count += 1; > + } > + > + return 0; > +} > + > +/* pseries_idle_devices_uninit(void) > + * unregister cpuidle devices and de-allocate memory > + */ > +static void pseries_idle_devices_uninit(void) > +{ > + int i; > + struct cpuidle_device *dev; > + > + for_each_possible_cpu(i) { > + dev = per_cpu_ptr(pseries_idle_cpuidle_devices, i); > + cpuidle_unregister_device(dev); > + } > + > + free_percpu(pseries_idle_cpuidle_devices); > + return; > +} > + > +/* pseries_idle_devices_init() > + * allocate, initialize and register cpuidle device > + */ > +static int pseries_idle_devices_init(void) > +{ > + int i; > + struct cpuidle_driver *drv = &pseries_idle_driver; > + struct cpuidle_device *dev; > + > + pseries_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device); > + if (pseries_idle_cpuidle_devices == NULL) > + return -ENOMEM; > + > + for_each_possible_cpu(i) { > + dev = per_cpu_ptr(pseries_idle_cpuidle_devices, i); > + dev->state_count = drv->state_count; > + dev->cpu = i; > + if (cpuidle_register_device(dev)) { > + printk(KERN_DEBUG \ > + "cpuidle_register_device %d failed!\n", i); > + return -EIO; > + } > + } > + > + return 0; > +} > + > +/* > + * pseries_idle_probe() > + * Choose state table for shared versus dedicated partition > + */ > +static int pseries_idle_probe(void) > +{ > + if (max_cstate == 0) { > + printk(KERN_DEBUG "pseries processor idle disabled.\n"); > + return -EPERM; > + } > + > + if (!firmware_has_feature(FW_FEATURE_SPLPAR)) { > + printk(KERN_DEBUG "Using default idle\n"); > + return -ENODEV; > + } Don't even printk here, this will happen on all !pseries machines and the debug output isn't useful. Also move the check of max-cstate to after the splpar test. Overall, I quite like these patches, my comments are all pretty minor, hopefully the next round should be the one. Cheers, Ben.
On 11/28/2011 04:33 AM, Benjamin Herrenschmidt wrote: > On Thu, 2011-11-17 at 16:58 +0530, Deepthi Dharwar wrote: >> This patch implements a backhand cpuidle driver for pSeries >> based on pseries_dedicated_idle_loop and pseries_shared_idle_loop >> routines. The driver is built only if CONFIG_CPU_IDLE is set. This >> cpuidle driver uses global registration of idle states and >> not per-cpu. > > .../... > >> +#define MAX_IDLE_STATE_COUNT 2 >> + >> +static int max_cstate = MAX_IDLE_STATE_COUNT - 1; > > Why "cstate" ? This isn't an x86 :-) Sure, I shall change it right away :) > >> +static struct cpuidle_device __percpu *pseries_idle_cpuidle_devices; > > Shorter name please. pseries_cpuidle_devs is fine. I ll do so. > >> +static struct cpuidle_state *cpuidle_state_table; >> + >> +void update_smt_snooze_delay(int snooze) >> +{ >> + struct cpuidle_driver *drv = cpuidle_get_driver(); >> + if (drv) >> + drv->states[0].target_residency = snooze; >> +} >> + >> +static inline void idle_loop_prolog(unsigned long *in_purr, ktime_t *kt_before) >> +{ >> + >> + *kt_before = ktime_get_real(); >> + *in_purr = mfspr(SPRN_PURR); >> + /* >> + * Indicate to the HV that we are idle. Now would be >> + * a good time to find other work to dispatch. >> + */ >> + get_lppaca()->idle = 1; >> + get_lppaca()->donate_dedicated_cpu = 1; >> +} > > I notice that you call this on shared processors as well. The old ocde > used to not set donate_dedicated_cpu in that case. I assume that's not a > big deal and that the HV will just ignore it in the shared processor > case but please add a comment after you've verified it. > Yes, the old code does not set donate_dedicated_cpu. But yes I will try testing it in a shared proc config but also remove this initialization for shared idle loop. >> +static inline s64 idle_loop_epilog(unsigned long in_purr, ktime_t kt_before) >> +{ >> + get_lppaca()->wait_state_cycles += mfspr(SPRN_PURR) - in_purr; >> + get_lppaca()->donate_dedicated_cpu = 0; >> + get_lppaca()->idle = 0; >> + >> + return ktime_to_us(ktime_sub(ktime_get_real(), kt_before)); >> +} >> + >> + >> +static int snooze_loop(struct cpuidle_device *dev, >> + struct cpuidle_driver *drv, >> + int index) >> +{ >> + unsigned long in_purr; >> + ktime_t kt_before; >> + >> + idle_loop_prolog(&in_purr, &kt_before); >> + >> + local_irq_enable(); >> + set_thread_flag(TIF_POLLING_NRFLAG); >> + while (!need_resched()) { >> + ppc64_runlatch_off(); >> + HMT_low(); >> + HMT_very_low(); >> + } >> + HMT_medium(); >> + clear_thread_flag(TIF_POLLING_NRFLAG); >> + smp_mb(); >> + local_irq_disable(); >> + >> + dev->last_residency = >> + (int)idle_loop_epilog(in_purr, kt_before); >> + return index; >> +} > > So your snooze loop has no timeout, is that handled by the cpuidle > driver using some kind of timer ? That sounds a lot less efficient than > passing a max delay to the snooze loop to handle getting into a deeper > state after a bit of snoozing rather than interrupting etc... My bad, snooze_loop is essential for a time out. Nope cpuidle driver doesn't have any timer mechanism. I ll fix it. Need to add loop for snooze time. >> +static int dedicated_cede_loop(struct cpuidle_device *dev, >> + struct cpuidle_driver *drv, >> + int index) >> +{ >> + unsigned long in_purr; >> + ktime_t kt_before; >> + >> + idle_loop_prolog(&in_purr, &kt_before); >> + >> + ppc64_runlatch_off(); >> + HMT_medium(); >> + cede_processor(); >> + >> + dev->last_residency = >> + (int)idle_loop_epilog(in_purr, kt_before); >> + return index; >> +} >> + >> +static int shared_cede_loop(struct cpuidle_device *dev, >> + struct cpuidle_driver *drv, >> + int index) >> +{ >> + unsigned long in_purr; >> + ktime_t kt_before; >> + >> + idle_loop_prolog(&in_purr, &kt_before); >> + >> + /* >> + * Yield the processor to the hypervisor. We return if >> + * an external interrupt occurs (which are driven prior >> + * to returning here) or if a prod occurs from another >> + * processor. When returning here, external interrupts >> + * are enabled. >> + */ >> + cede_processor(); >> + >> + dev->last_residency = >> + (int)idle_loop_epilog(in_purr, kt_before); >> + return index; >> +} >> + >> +/* >> + * States for dedicated partition case. >> + */ >> +static struct cpuidle_state dedicated_states[MAX_IDLE_STATE_COUNT] = { >> + { /* Snooze */ >> + .name = "snooze", >> + .desc = "snooze", >> + .flags = CPUIDLE_FLAG_TIME_VALID, >> + .exit_latency = 0, >> + .target_residency = 0, >> + .enter = &snooze_loop }, >> + { /* CEDE */ >> + .name = "CEDE", >> + .desc = "CEDE", >> + .flags = CPUIDLE_FLAG_TIME_VALID, >> + .exit_latency = 1, >> + .target_residency = 10, >> + .enter = &dedicated_cede_loop }, >> +}; >> + >> +/* >> + * States for shared partition case. >> + */ >> +static struct cpuidle_state shared_states[MAX_IDLE_STATE_COUNT] = { >> + { /* Shared Cede */ >> + .name = "Shared Cede", >> + .desc = "Shared Cede", >> + .flags = CPUIDLE_FLAG_TIME_VALID, >> + .exit_latency = 0, >> + .target_residency = 0, >> + .enter = &shared_cede_loop }, >> +}; >> + >> +int pseries_notify_cpuidle_add_cpu(int cpu) >> +{ >> + struct cpuidle_device *dev = >> + per_cpu_ptr(pseries_idle_cpuidle_devices, cpu); >> + if (dev && cpuidle_get_driver()) { >> + cpuidle_disable_device(dev); >> + cpuidle_enable_device(dev); >> + } >> + return 0; >> +} >> + >> +/* >> + * pseries_idle_cpuidle_driver_init() >> + */ >> +static int pseries_idle_cpuidle_driver_init(void) >> +{ > > Drop the "idle", those names are too long. Sure. > >> + int cstate; > > And use something else than 'cstate', we are among civilized people > here ;-) Yes :) > >> + struct cpuidle_driver *drv = &pseries_idle_driver; >> + >> + drv->state_count = 0; >> + >> + for (cstate = 0; cstate < MAX_IDLE_STATE_COUNT; ++cstate) { >> + >> + if (cstate > max_cstate) >> + break; >> + >> + /* is the state not enabled? */ >> + if (cpuidle_state_table[cstate].enter == NULL) >> + continue; >> + >> + drv->states[drv->state_count] = /* structure copy */ >> + cpuidle_state_table[cstate]; >> + >> + if (cpuidle_state_table == dedicated_states) >> + drv->states[drv->state_count].target_residency = >> + __get_cpu_var(smt_snooze_delay); >> + >> + drv->state_count += 1; >> + } >> + >> + return 0; >> +} >> + >> +/* pseries_idle_devices_uninit(void) >> + * unregister cpuidle devices and de-allocate memory >> + */ >> +static void pseries_idle_devices_uninit(void) >> +{ >> + int i; >> + struct cpuidle_device *dev; >> + >> + for_each_possible_cpu(i) { >> + dev = per_cpu_ptr(pseries_idle_cpuidle_devices, i); >> + cpuidle_unregister_device(dev); >> + } >> + >> + free_percpu(pseries_idle_cpuidle_devices); >> + return; >> +} >> + >> +/* pseries_idle_devices_init() >> + * allocate, initialize and register cpuidle device >> + */ >> +static int pseries_idle_devices_init(void) >> +{ >> + int i; >> + struct cpuidle_driver *drv = &pseries_idle_driver; >> + struct cpuidle_device *dev; >> + >> + pseries_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device); >> + if (pseries_idle_cpuidle_devices == NULL) >> + return -ENOMEM; >> + >> + for_each_possible_cpu(i) { >> + dev = per_cpu_ptr(pseries_idle_cpuidle_devices, i); >> + dev->state_count = drv->state_count; >> + dev->cpu = i; >> + if (cpuidle_register_device(dev)) { >> + printk(KERN_DEBUG \ >> + "cpuidle_register_device %d failed!\n", i); >> + return -EIO; >> + } >> + } >> + >> + return 0; >> +} >> + >> +/* >> + * pseries_idle_probe() >> + * Choose state table for shared versus dedicated partition >> + */ >> +static int pseries_idle_probe(void) >> +{ >> + if (max_cstate == 0) { >> + printk(KERN_DEBUG "pseries processor idle disabled.\n"); >> + return -EPERM; >> + } >> + >> + if (!firmware_has_feature(FW_FEATURE_SPLPAR)) { >> + printk(KERN_DEBUG "Using default idle\n"); >> + return -ENODEV; >> + } > > Don't even printk here, this will happen on all !pseries machines and > the debug output isn't useful. Also move the check of max-cstate to > after the splpar test. I ll move the check above. > Overall, I quite like these patches, my comments are all pretty minor, > hopefully the next round should be the one. Thank you. > > Cheers, > Ben. > > Regards, Deepthi
diff --git a/arch/powerpc/include/asm/system.h b/arch/powerpc/include/asm/system.h index ff66680..f56a0a7 100644 --- a/arch/powerpc/include/asm/system.h +++ b/arch/powerpc/include/asm/system.h @@ -223,6 +223,14 @@ extern void *zalloc_maybe_bootmem(size_t size, gfp_t mask); extern int powersave_nap; /* set if nap mode can be used in idle loop */ void cpu_idle_wait(void); +#ifdef CONFIG_PSERIES_IDLE +extern void update_smt_snooze_delay(int snooze); +extern int pseries_notify_cpuidle_add_cpu(int cpu); +#else +static inline void update_smt_snooze_delay(int snooze) {} +static inline int pseries_notify_cpuidle_add_cpu(int cpu) { return 0; } +#endif + /* * Atomic exchange * diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c index ce035c1..ebe5d78 100644 --- a/arch/powerpc/kernel/sysfs.c +++ b/arch/powerpc/kernel/sysfs.c @@ -18,6 +18,7 @@ #include <asm/machdep.h> #include <asm/smp.h> #include <asm/pmc.h> +#include <asm/system.h> #include "cacheinfo.h" @@ -51,6 +52,7 @@ static ssize_t store_smt_snooze_delay(struct sys_device *dev, return -EINVAL; per_cpu(smt_snooze_delay, cpu->sysdev.id) = snooze; + update_smt_snooze_delay(snooze); return count; } diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig index c81f6bb..ae7b6d4 100644 --- a/arch/powerpc/platforms/pseries/Kconfig +++ b/arch/powerpc/platforms/pseries/Kconfig @@ -120,3 +120,12 @@ config DTL which are accessible through a debugfs file. Say N if you are unsure. + +config PSERIES_IDLE + tristate "Cpuidle driver for pSeries platforms" + depends on CPU_IDLE + depends on PPC_PSERIES + default y + help + Select this option to enable processor idle state management + through cpuidle subsystem. diff --git a/arch/powerpc/platforms/pseries/Makefile b/arch/powerpc/platforms/pseries/Makefile index 3556e40..236db46 100644 --- a/arch/powerpc/platforms/pseries/Makefile +++ b/arch/powerpc/platforms/pseries/Makefile @@ -22,6 +22,7 @@ obj-$(CONFIG_PHYP_DUMP) += phyp_dump.o obj-$(CONFIG_CMM) += cmm.o obj-$(CONFIG_DTL) += dtl.o obj-$(CONFIG_IO_EVENT_IRQ) += io_event_irq.o +obj-$(CONFIG_PSERIES_IDLE) += processor_idle.o ifeq ($(CONFIG_PPC_PSERIES),y) obj-$(CONFIG_SUSPEND) += suspend.o diff --git a/arch/powerpc/platforms/pseries/processor_idle.c b/arch/powerpc/platforms/pseries/processor_idle.c new file mode 100644 index 0000000..b5addd7 --- /dev/null +++ b/arch/powerpc/platforms/pseries/processor_idle.c @@ -0,0 +1,317 @@ +/* + * processor_idle - idle state cpuidle driver. + * Adapted from drivers/idle/intel_idle.c and + * drivers/acpi/processor_idle.c + * + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/moduleparam.h> +#include <linux/cpuidle.h> +#include <linux/cpu.h> + +#include <asm/paca.h> +#include <asm/reg.h> +#include <asm/system.h> +#include <asm/machdep.h> +#include <asm/firmware.h> + +#include "plpar_wrappers.h" +#include "pseries.h" + +struct cpuidle_driver pseries_idle_driver = { + .name = "pseries_idle", + .owner = THIS_MODULE, +}; + +#define MAX_IDLE_STATE_COUNT 2 + +static int max_cstate = MAX_IDLE_STATE_COUNT - 1; +static struct cpuidle_device __percpu *pseries_idle_cpuidle_devices; +static struct cpuidle_state *cpuidle_state_table; + +void update_smt_snooze_delay(int snooze) +{ + struct cpuidle_driver *drv = cpuidle_get_driver(); + if (drv) + drv->states[0].target_residency = snooze; +} + +static inline void idle_loop_prolog(unsigned long *in_purr, ktime_t *kt_before) +{ + + *kt_before = ktime_get_real(); + *in_purr = mfspr(SPRN_PURR); + /* + * Indicate to the HV that we are idle. Now would be + * a good time to find other work to dispatch. + */ + get_lppaca()->idle = 1; + get_lppaca()->donate_dedicated_cpu = 1; +} + +static inline s64 idle_loop_epilog(unsigned long in_purr, ktime_t kt_before) +{ + get_lppaca()->wait_state_cycles += mfspr(SPRN_PURR) - in_purr; + get_lppaca()->donate_dedicated_cpu = 0; + get_lppaca()->idle = 0; + + return ktime_to_us(ktime_sub(ktime_get_real(), kt_before)); +} + + +static int snooze_loop(struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index) +{ + unsigned long in_purr; + ktime_t kt_before; + + idle_loop_prolog(&in_purr, &kt_before); + + local_irq_enable(); + set_thread_flag(TIF_POLLING_NRFLAG); + while (!need_resched()) { + ppc64_runlatch_off(); + HMT_low(); + HMT_very_low(); + } + HMT_medium(); + clear_thread_flag(TIF_POLLING_NRFLAG); + smp_mb(); + local_irq_disable(); + + dev->last_residency = + (int)idle_loop_epilog(in_purr, kt_before); + return index; +} + +static int dedicated_cede_loop(struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index) +{ + unsigned long in_purr; + ktime_t kt_before; + + idle_loop_prolog(&in_purr, &kt_before); + + ppc64_runlatch_off(); + HMT_medium(); + cede_processor(); + + dev->last_residency = + (int)idle_loop_epilog(in_purr, kt_before); + return index; +} + +static int shared_cede_loop(struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index) +{ + unsigned long in_purr; + ktime_t kt_before; + + idle_loop_prolog(&in_purr, &kt_before); + + /* + * Yield the processor to the hypervisor. We return if + * an external interrupt occurs (which are driven prior + * to returning here) or if a prod occurs from another + * processor. When returning here, external interrupts + * are enabled. + */ + cede_processor(); + + dev->last_residency = + (int)idle_loop_epilog(in_purr, kt_before); + return index; +} + +/* + * States for dedicated partition case. + */ +static struct cpuidle_state dedicated_states[MAX_IDLE_STATE_COUNT] = { + { /* Snooze */ + .name = "snooze", + .desc = "snooze", + .flags = CPUIDLE_FLAG_TIME_VALID, + .exit_latency = 0, + .target_residency = 0, + .enter = &snooze_loop }, + { /* CEDE */ + .name = "CEDE", + .desc = "CEDE", + .flags = CPUIDLE_FLAG_TIME_VALID, + .exit_latency = 1, + .target_residency = 10, + .enter = &dedicated_cede_loop }, +}; + +/* + * States for shared partition case. + */ +static struct cpuidle_state shared_states[MAX_IDLE_STATE_COUNT] = { + { /* Shared Cede */ + .name = "Shared Cede", + .desc = "Shared Cede", + .flags = CPUIDLE_FLAG_TIME_VALID, + .exit_latency = 0, + .target_residency = 0, + .enter = &shared_cede_loop }, +}; + +int pseries_notify_cpuidle_add_cpu(int cpu) +{ + struct cpuidle_device *dev = + per_cpu_ptr(pseries_idle_cpuidle_devices, cpu); + if (dev && cpuidle_get_driver()) { + cpuidle_disable_device(dev); + cpuidle_enable_device(dev); + } + return 0; +} + +/* + * pseries_idle_cpuidle_driver_init() + */ +static int pseries_idle_cpuidle_driver_init(void) +{ + int cstate; + struct cpuidle_driver *drv = &pseries_idle_driver; + + drv->state_count = 0; + + for (cstate = 0; cstate < MAX_IDLE_STATE_COUNT; ++cstate) { + + if (cstate > max_cstate) + break; + + /* is the state not enabled? */ + if (cpuidle_state_table[cstate].enter == NULL) + continue; + + drv->states[drv->state_count] = /* structure copy */ + cpuidle_state_table[cstate]; + + if (cpuidle_state_table == dedicated_states) + drv->states[drv->state_count].target_residency = + __get_cpu_var(smt_snooze_delay); + + drv->state_count += 1; + } + + return 0; +} + +/* pseries_idle_devices_uninit(void) + * unregister cpuidle devices and de-allocate memory + */ +static void pseries_idle_devices_uninit(void) +{ + int i; + struct cpuidle_device *dev; + + for_each_possible_cpu(i) { + dev = per_cpu_ptr(pseries_idle_cpuidle_devices, i); + cpuidle_unregister_device(dev); + } + + free_percpu(pseries_idle_cpuidle_devices); + return; +} + +/* pseries_idle_devices_init() + * allocate, initialize and register cpuidle device + */ +static int pseries_idle_devices_init(void) +{ + int i; + struct cpuidle_driver *drv = &pseries_idle_driver; + struct cpuidle_device *dev; + + pseries_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device); + if (pseries_idle_cpuidle_devices == NULL) + return -ENOMEM; + + for_each_possible_cpu(i) { + dev = per_cpu_ptr(pseries_idle_cpuidle_devices, i); + dev->state_count = drv->state_count; + dev->cpu = i; + if (cpuidle_register_device(dev)) { + printk(KERN_DEBUG \ + "cpuidle_register_device %d failed!\n", i); + return -EIO; + } + } + + return 0; +} + +/* + * pseries_idle_probe() + * Choose state table for shared versus dedicated partition + */ +static int pseries_idle_probe(void) +{ + if (max_cstate == 0) { + printk(KERN_DEBUG "pseries processor idle disabled.\n"); + return -EPERM; + } + + if (!firmware_has_feature(FW_FEATURE_SPLPAR)) { + printk(KERN_DEBUG "Using default idle\n"); + return -ENODEV; + } + + if (get_lppaca()->shared_proc) + cpuidle_state_table = shared_states; + else + cpuidle_state_table = dedicated_states; + + return 0; +} + +static int __init pseries_processor_idle_init(void) +{ + int retval; + + retval = pseries_idle_probe(); + if (retval) + return retval; + + pseries_idle_cpuidle_driver_init(); + retval = cpuidle_register_driver(&pseries_idle_driver); + if (retval) { + printk(KERN_DEBUG "Registration of pseries driver failed.\n"); + return retval; + } + + retval = pseries_idle_devices_init(); + if (retval) { + pseries_idle_devices_uninit(); + cpuidle_unregister_driver(&pseries_idle_driver); + return retval; + } + + printk(KERN_DEBUG "pseries_idle_driver registered\n"); + + return 0; +} + +static void __exit pseries_processor_idle_exit(void) +{ + + pseries_idle_devices_uninit(); + cpuidle_unregister_driver(&pseries_idle_driver); + + return; +} + +module_init(pseries_processor_idle_init); +module_exit(pseries_processor_idle_exit); + +MODULE_AUTHOR("Deepthi Dharwar <deepthi@linux.vnet.ibm.com>"); +MODULE_DESCRIPTION("Cpuidle driver for POWER"); +MODULE_LICENSE("GPL"); diff --git a/arch/powerpc/platforms/pseries/pseries.h b/arch/powerpc/platforms/pseries/pseries.h index 24c7162..9a3dda0 100644 --- a/arch/powerpc/platforms/pseries/pseries.h +++ b/arch/powerpc/platforms/pseries/pseries.h @@ -57,4 +57,7 @@ extern struct device_node *dlpar_configure_connector(u32); extern int dlpar_attach_node(struct device_node *); extern int dlpar_detach_node(struct device_node *); +/* Snooze Delay, pseries_idle */ +DECLARE_PER_CPU(long, smt_snooze_delay); + #endif /* _PSERIES_PSERIES_H */ diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c index c3408ca..9c6716a 100644 --- a/arch/powerpc/platforms/pseries/setup.c +++ b/arch/powerpc/platforms/pseries/setup.c @@ -586,9 +586,6 @@ static int __init pSeries_probe(void) return 1; } - -DECLARE_PER_CPU(long, smt_snooze_delay); - static void pseries_dedicated_idle_sleep(void) { unsigned int cpu = smp_processor_id(); diff --git a/arch/powerpc/platforms/pseries/smp.c b/arch/powerpc/platforms/pseries/smp.c index 26e93fd..bbc3c42 100644 --- a/arch/powerpc/platforms/pseries/smp.c +++ b/arch/powerpc/platforms/pseries/smp.c @@ -148,6 +148,7 @@ static void __devinit smp_xics_setup_cpu(int cpu) set_cpu_current_state(cpu, CPU_STATE_ONLINE); set_default_offline_state(cpu); #endif + pseries_notify_cpuidle_add_cpu(cpu); } static int __devinit smp_pSeries_kick_cpu(int nr)