[PATCH V2] cpufreq: powernv: Add boost files to export ultra-turbo frequencies

From: Shilpasri G Bhat
Date: Tue Jan 03 2017 - 06:06:30 EST


In P8+, Workload Optimized Frequency(WOF) provides the capability to
boost the cpu frequency based on the utilization of the other cpus
running in the chip. The On-Chip-Controller(OCC) firmware will control
the achievability of these frequencies depending on the power headroom
available in the chip. Currently the ultra-turbo frequencies provided
by this feature are exported along with the turbo and sub-turbo
frequencies as scaling_available_frequencies. This patch will export
the ultra-turbo frequencies separately as scaling_boost_frequencies in
WOF enabled systems. This patch will add the boost sysfs file which
can be used to disable/enable ultra-turbo frequencies.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Gautham R. Shenoy <ego@xxxxxxxxxxxxxxxxxx>
---
Changes from v1:
- Print if WOF is enabled
- s/clean_notifiers/cleanup_notifiers

drivers/cpufreq/powernv-cpufreq.c | 50 ++++++++++++++++++++++++++++++++++++---
1 file changed, 47 insertions(+), 3 deletions(-)

diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
index 37671b5..3ff5160 100644
--- a/drivers/cpufreq/powernv-cpufreq.c
+++ b/drivers/cpufreq/powernv-cpufreq.c
@@ -144,6 +144,7 @@ enum throttle_reason_type {
unsigned int max;
unsigned int nominal;
unsigned int nr_pstates;
+ bool wof_enabled;
} powernv_pstate_info;

/* Use following macros for conversions between pstate_id and index */
@@ -203,6 +204,7 @@ static int init_powernv_pstates(void)
const __be32 *pstate_ids, *pstate_freqs;
u32 len_ids, len_freqs;
u32 pstate_min, pstate_max, pstate_nominal;
+ u32 pstate_turbo, pstate_ultra_turbo;

power_mgt = of_find_node_by_path("/ibm,opal/power-mgt");
if (!power_mgt) {
@@ -225,8 +227,29 @@ static int init_powernv_pstates(void)
pr_warn("ibm,pstate-nominal not found\n");
return -ENODEV;
}
+
+ if (of_property_read_u32(power_mgt, "ibm,pstate-ultra-turbo",
+ &pstate_ultra_turbo)) {
+ powernv_pstate_info.wof_enabled = false;
+ goto next;
+ }
+
+ if (of_property_read_u32(power_mgt, "ibm,pstate-turbo",
+ &pstate_turbo)) {
+ powernv_pstate_info.wof_enabled = false;
+ goto next;
+ }
+
+ if (pstate_turbo == pstate_ultra_turbo)
+ powernv_pstate_info.wof_enabled = false;
+ else
+ powernv_pstate_info.wof_enabled = true;
+
+next:
pr_info("cpufreq pstate min %d nominal %d max %d\n", pstate_min,
pstate_nominal, pstate_max);
+ pr_info("Workload Optimized Frequency is %s in the platform\n",
+ (powernv_pstate_info.wof_enabled) ? "enabled" : "disabled");

pstate_ids = of_get_property(power_mgt, "ibm,pstate-ids", &len_ids);
if (!pstate_ids) {
@@ -268,6 +291,13 @@ static int init_powernv_pstates(void)
powernv_pstate_info.nominal = i;
else if (id == pstate_min)
powernv_pstate_info.min = i;
+
+ if (powernv_pstate_info.wof_enabled && id == pstate_turbo) {
+ int j;
+
+ for (j = i - 1; j >= (int)powernv_pstate_info.max; j--)
+ powernv_freqs[j].flags = CPUFREQ_BOOST_FREQ;
+ }
}

/* End of list marker entry */
@@ -305,9 +335,12 @@ static ssize_t cpuinfo_nominal_freq_show(struct cpufreq_policy *policy,
struct freq_attr cpufreq_freq_attr_cpuinfo_nominal_freq =
__ATTR_RO(cpuinfo_nominal_freq);

+#define SCALING_BOOST_FREQS_ATTR_INDEX 2
+
static struct freq_attr *powernv_cpu_freq_attr[] = {
&cpufreq_freq_attr_scaling_available_freqs,
&cpufreq_freq_attr_cpuinfo_nominal_freq,
+ &cpufreq_freq_attr_scaling_boost_freqs,
NULL,
};

@@ -1013,11 +1046,22 @@ static int __init powernv_cpufreq_init(void)
register_reboot_notifier(&powernv_cpufreq_reboot_nb);
opal_message_notifier_register(OPAL_MSG_OCC, &powernv_cpufreq_opal_nb);

+ if (powernv_pstate_info.wof_enabled)
+ powernv_cpufreq_driver.boost_enabled = true;
+ else
+ powernv_cpu_freq_attr[SCALING_BOOST_FREQS_ATTR_INDEX] = NULL;
+
rc = cpufreq_register_driver(&powernv_cpufreq_driver);
- if (!rc)
- return 0;
+ if (rc) {
+ pr_info("Failed to register the cpufreq driver (%d)\n", rc);
+ goto cleanup_notifiers;
+ }

- pr_info("Failed to register the cpufreq driver (%d)\n", rc);
+ if (powernv_pstate_info.wof_enabled)
+ cpufreq_enable_boost_support();
+
+ return 0;
+cleanup_notifiers:
unregister_all_notifiers();
clean_chip_info();
out:
--
1.8.3.1