| Message ID | 1430729652-14813-4-git-send-email-shilpa.bhat@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On 05/04/2015 02:24 PM, Shilpasri G Bhat wrote: > OCC is an On-Chip-Controller which takes care of power and thermal > safety of the chip. During runtime due to power failure or > overtemperature the OCC may throttle the frequencies of the CPUs to > remain within the power budget. > > We want the cpufreq driver to be aware of such situations to be able > to report the reason to the user. We register to opal_message_notifier > to receive OCC messages from opal. > > powernv_cpufreq_throttle_check() reports any frequency throttling and > this patch will report the reason or event that caused throttling. We > can be throttled if OCC is reset or OCC limits Pmax due to power or > thermal reasons. We are also notified of unthrottling after an OCC > reset or if OCC restores Pmax on the chip. > > Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> > --- > Changes from v2: > - Patch split in to multiple patches. > - This patch contains only the opal_message notification handler > > Changes from v1: > - Add macros to define OCC_RESET, OCC_LOAD and OCC_THROTTLE > - Define a structure to store chip id, chip mask which has bits set > for cpus present in the chip, throttled state and a work_struct. > - Modify powernv_cpufreq_throttle_check() to be called via smp_call() > - On Pmax throttling/unthrottling update 'chip.throttled' and not the > global 'throttled' as Pmax capping is local to the chip. > - Remove the condition which checks if local pstate is less than Pmin > while checking for Psafe frequency. When OCC becomes active after > reset we update 'thottled' to false and when the cpufreq governor > initiates a pstate change, the local pstate will be in Psafe and we > will be reporting a false positive when we are not throttled. > - Schedule a kworker on receiving throttling/unthrottling OCC message > for that chip and schedule on all chips after receiving active. > - After an OCC reset all the cpus will be in Psafe frequency. So call > target() and restore the frequency to policy->cur after OCC_ACTIVE > and Pmax unthrottling > - Taken care of Viresh and Preeti's comments. > > drivers/cpufreq/powernv-cpufreq.c | 75 ++++++++++++++++++++++++++++++++++++++- > 1 file changed, 74 insertions(+), 1 deletion(-) > > diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c > index d0c18c9..9268424 100644 > --- a/drivers/cpufreq/powernv-cpufreq.c > +++ b/drivers/cpufreq/powernv-cpufreq.c > @@ -33,15 +33,19 @@ > #include <asm/firmware.h> > #include <asm/reg.h> > #include <asm/smp.h> /* Required for cpu_sibling_mask() in UP configs */ > +#include <asm/opal.h> > > #define POWERNV_MAX_PSTATES 256 > #define PMSR_PSAFE_ENABLE (1UL << 30) > #define PMSR_SPR_EM_DISABLE (1UL << 31) > #define PMSR_MAX(x) ((x >> 32) & 0xFF) > #define PMSR_LP(x) ((x >> 48) & 0xFF) > +#define OCC_RESET 0 > +#define OCC_LOAD 1 > +#define OCC_THROTTLE 2 > > static struct cpufreq_frequency_table powernv_freqs[POWERNV_MAX_PSTATES+1]; > -static bool rebooting, throttled; > +static bool rebooting, throttled, occ_reset; > > static struct chip { > unsigned int id; > @@ -414,6 +418,74 @@ static struct notifier_block powernv_cpufreq_reboot_nb = { > .notifier_call = powernv_cpufreq_reboot_notifier, > }; > > +static char throttle_reason[][30] = { > + "No throttling", > + "Power Cap", > + "Processor Over Temperature", > + "Power Supply Failure", > + "Over Current", > + "OCC Reset" > + }; > + > +static int powernv_cpufreq_occ_msg(struct notifier_block *nb, > + unsigned long msg_type, void *msg) > +{ > + struct opal_msg *occ_msg = msg; > + uint64_t token; > + uint64_t chip_id, reason; > + > + if (msg_type != OPAL_MSG_OCC) > + return 0; > + > + token = be64_to_cpu(occ_msg->params[0]); > + > + switch (token) { > + case OCC_RESET: > + occ_reset = true; > + /* > + * powernv_cpufreq_throttle_check() is called in > + * target() callback which can detect the throttle state > + * for governors like ondemand. > + * But static governors will not call target() often thus > + * report throttling here. > + */ > + if (!throttled) { > + throttled = true; > + pr_crit("CPU Frequency is throttled\n"); > + } > + pr_info("OCC: Reset\n"); > + break; > + case OCC_LOAD: > + pr_info("OCC: Loaded\n"); > + break; > + case OCC_THROTTLE: > + chip_id = be64_to_cpu(occ_msg->params[1]); > + reason = be64_to_cpu(occ_msg->params[2]); > + > + if (occ_reset) { > + occ_reset = false; > + throttled = false; > + pr_info("OCC: Active\n"); > + return 0; > + } > + > + if (reason && reason <= 5) > + pr_info("OCC: Chip %u Pmax reduced due to %s\n", > + (unsigned int)chip_id, > + throttle_reason[reason]); > + else if (!reason) > + pr_info("OCC: Chip %u %s\n", (unsigned int)chip_id, > + throttle_reason[reason]); > + } > + return 0; > +} > + > +static struct notifier_block powernv_cpufreq_opal_nb = { > + .notifier_call = powernv_cpufreq_occ_msg, > + .next = NULL, > + .priority = 0, > +}; > + > static void powernv_cpufreq_stop_cpu(struct cpufreq_policy *policy) > { > struct powernv_smp_call_data freq_data; > @@ -481,6 +553,7 @@ static int __init powernv_cpufreq_init(void) > return rc; > > register_reboot_notifier(&powernv_cpufreq_reboot_nb); > + opal_message_notifier_register(OPAL_MSG_OCC, &powernv_cpufreq_opal_nb); > return cpufreq_register_driver(&powernv_cpufreq_driver); > } > module_init(powernv_cpufreq_init); > Looks good. Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c index d0c18c9..9268424 100644 --- a/drivers/cpufreq/powernv-cpufreq.c +++ b/drivers/cpufreq/powernv-cpufreq.c @@ -33,15 +33,19 @@ #include <asm/firmware.h> #include <asm/reg.h> #include <asm/smp.h> /* Required for cpu_sibling_mask() in UP configs */ +#include <asm/opal.h> #define POWERNV_MAX_PSTATES 256 #define PMSR_PSAFE_ENABLE (1UL << 30) #define PMSR_SPR_EM_DISABLE (1UL << 31) #define PMSR_MAX(x) ((x >> 32) & 0xFF) #define PMSR_LP(x) ((x >> 48) & 0xFF) +#define OCC_RESET 0 +#define OCC_LOAD 1 +#define OCC_THROTTLE 2 static struct cpufreq_frequency_table powernv_freqs[POWERNV_MAX_PSTATES+1]; -static bool rebooting, throttled; +static bool rebooting, throttled, occ_reset; static struct chip { unsigned int id; @@ -414,6 +418,74 @@ static struct notifier_block powernv_cpufreq_reboot_nb = { .notifier_call = powernv_cpufreq_reboot_notifier, }; +static char throttle_reason[][30] = { + "No throttling", + "Power Cap", + "Processor Over Temperature", + "Power Supply Failure", + "Over Current", + "OCC Reset" + }; + +static int powernv_cpufreq_occ_msg(struct notifier_block *nb, + unsigned long msg_type, void *msg) +{ + struct opal_msg *occ_msg = msg; + uint64_t token; + uint64_t chip_id, reason; + + if (msg_type != OPAL_MSG_OCC) + return 0; + + token = be64_to_cpu(occ_msg->params[0]); + + switch (token) { + case OCC_RESET: + occ_reset = true; + /* + * powernv_cpufreq_throttle_check() is called in + * target() callback which can detect the throttle state + * for governors like ondemand. + * But static governors will not call target() often thus + * report throttling here. + */ + if (!throttled) { + throttled = true; + pr_crit("CPU Frequency is throttled\n"); + } + pr_info("OCC: Reset\n"); + break; + case OCC_LOAD: + pr_info("OCC: Loaded\n"); + break; + case OCC_THROTTLE: + chip_id = be64_to_cpu(occ_msg->params[1]); + reason = be64_to_cpu(occ_msg->params[2]); + + if (occ_reset) { + occ_reset = false; + throttled = false; + pr_info("OCC: Active\n"); + return 0; + } + + if (reason && reason <= 5) + pr_info("OCC: Chip %u Pmax reduced due to %s\n", + (unsigned int)chip_id, + throttle_reason[reason]); + else if (!reason) + pr_info("OCC: Chip %u %s\n", (unsigned int)chip_id, + throttle_reason[reason]); + } + return 0; +} + +static struct notifier_block powernv_cpufreq_opal_nb = { + .notifier_call = powernv_cpufreq_occ_msg, + .next = NULL, + .priority = 0, +}; + static void powernv_cpufreq_stop_cpu(struct cpufreq_policy *policy) { struct powernv_smp_call_data freq_data; @@ -481,6 +553,7 @@ static int __init powernv_cpufreq_init(void) return rc; register_reboot_notifier(&powernv_cpufreq_reboot_nb); + opal_message_notifier_register(OPAL_MSG_OCC, &powernv_cpufreq_opal_nb); return cpufreq_register_driver(&powernv_cpufreq_driver); } module_init(powernv_cpufreq_init);
OCC is an On-Chip-Controller which takes care of power and thermal safety of the chip. During runtime due to power failure or overtemperature the OCC may throttle the frequencies of the CPUs to remain within the power budget. We want the cpufreq driver to be aware of such situations to be able to report the reason to the user. We register to opal_message_notifier to receive OCC messages from opal. powernv_cpufreq_throttle_check() reports any frequency throttling and this patch will report the reason or event that caused throttling. We can be throttled if OCC is reset or OCC limits Pmax due to power or thermal reasons. We are also notified of unthrottling after an OCC reset or if OCC restores Pmax on the chip. Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> --- Changes from v2: - Patch split in to multiple patches. - This patch contains only the opal_message notification handler Changes from v1: - Add macros to define OCC_RESET, OCC_LOAD and OCC_THROTTLE - Define a structure to store chip id, chip mask which has bits set for cpus present in the chip, throttled state and a work_struct. - Modify powernv_cpufreq_throttle_check() to be called via smp_call() - On Pmax throttling/unthrottling update 'chip.throttled' and not the global 'throttled' as Pmax capping is local to the chip. - Remove the condition which checks if local pstate is less than Pmin while checking for Psafe frequency. When OCC becomes active after reset we update 'thottled' to false and when the cpufreq governor initiates a pstate change, the local pstate will be in Psafe and we will be reporting a false positive when we are not throttled. - Schedule a kworker on receiving throttling/unthrottling OCC message for that chip and schedule on all chips after receiving active. - After an OCC reset all the cpus will be in Psafe frequency. So call target() and restore the frequency to policy->cur after OCC_ACTIVE and Pmax unthrottling - Taken care of Viresh and Preeti's comments. drivers/cpufreq/powernv-cpufreq.c | 75 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 74 insertions(+), 1 deletion(-)