From 92c83ff5b42b109c94fdeee53cb31f674f776d75 Mon Sep 17 00:00:00 2001 From: Preeti U Murthy Date: Wed, 18 Feb 2015 06:34:17 +0100 Subject: cpuidle: powernv: Read target_residency value of idle states from DT if available The device tree now exposes the residency values for different idle states. Read these values instead of calculating residency from the latency values. The values exposed in the DT are validated for optimal power efficiency. However to maintain compatibility with the older firmware code which does not expose residency values, use default values as a fallback mechanism. While at it, use better APIs to parse the powermgmt device tree node. Signed-off-by: Preeti U Murthy Acked-by: Stewart Smith Acked-by: Michael Ellerman Signed-off-by: Rafael J. Wysocki --- drivers/cpuidle/cpuidle-powernv.c | 69 +++++++++++++++++++++++---------------- 1 file changed, 40 insertions(+), 29 deletions(-) (limited to 'drivers/cpuidle') diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c index aedec0957934..30d42298a69f 100644 --- a/drivers/cpuidle/cpuidle-powernv.c +++ b/drivers/cpuidle/cpuidle-powernv.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include @@ -159,69 +160,79 @@ static int powernv_add_idle_states(void) int nr_idle_states = 1; /* Snooze */ int dt_idle_states; const __be32 *idle_state_flags; - const __be32 *idle_state_latency; - u32 len_flags, flags, latency_ns; - int i; + u32 len_flags, flags; + u32 *latency_ns, *residency_ns; + int i, rc; /* Currently we have snooze statically defined */ power_mgt = of_find_node_by_path("/ibm,opal/power-mgt"); if (!power_mgt) { pr_warn("opal: PowerMgmt Node not found\n"); - return nr_idle_states; + goto out; } - idle_state_flags = of_get_property(power_mgt, "ibm,cpu-idle-state-flags", &len_flags); + idle_state_flags = of_get_property(power_mgt, + "ibm,cpu-idle-state-flags", &len_flags); if (!idle_state_flags) { - pr_warn("DT-PowerMgmt: missing ibm,cpu-idle-state-flags\n"); - return nr_idle_states; + pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-flags in DT\n"); + goto out; } - idle_state_latency = of_get_property(power_mgt, - "ibm,cpu-idle-state-latencies-ns", NULL); - if (!idle_state_latency) { - pr_warn("DT-PowerMgmt: missing ibm,cpu-idle-state-latencies-ns\n"); - return nr_idle_states; + dt_idle_states = len_flags / sizeof(u32); + + latency_ns = kzalloc(sizeof(*latency_ns) * dt_idle_states, GFP_KERNEL); + rc = of_property_read_u32_array(power_mgt, + "ibm,cpu-idle-state-latencies-ns", latency_ns, dt_idle_states); + if (rc) { + pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-latencies-ns in DT\n"); + goto out_free_latency; } - dt_idle_states = len_flags / sizeof(u32); + residency_ns = kzalloc(sizeof(*residency_ns) * dt_idle_states, GFP_KERNEL); + rc = of_property_read_u32_array(power_mgt, + "ibm,cpu-idle-state-residency-ns", residency_ns, dt_idle_states); for (i = 0; i < dt_idle_states; i++) { flags = be32_to_cpu(idle_state_flags[i]); - /* Cpuidle accepts exit_latency in us and we estimate - * target residency to be 10x exit_latency + /* + * Cpuidle accepts exit_latency and target_residency in us. + * Use default target_residency values if f/w does not expose it. */ - latency_ns = be32_to_cpu(idle_state_latency[i]); if (flags & OPAL_PM_NAP_ENABLED) { /* Add NAP state */ strcpy(powernv_states[nr_idle_states].name, "Nap"); strcpy(powernv_states[nr_idle_states].desc, "Nap"); powernv_states[nr_idle_states].flags = 0; - powernv_states[nr_idle_states].exit_latency = - ((unsigned int)latency_ns) / 1000; - powernv_states[nr_idle_states].target_residency = - ((unsigned int)latency_ns / 100); + powernv_states[nr_idle_states].target_residency = 100; powernv_states[nr_idle_states].enter = &nap_loop; - nr_idle_states++; - } - - if (flags & OPAL_PM_SLEEP_ENABLED || + } else if (flags & OPAL_PM_SLEEP_ENABLED || flags & OPAL_PM_SLEEP_ENABLED_ER1) { /* Add FASTSLEEP state */ strcpy(powernv_states[nr_idle_states].name, "FastSleep"); strcpy(powernv_states[nr_idle_states].desc, "FastSleep"); powernv_states[nr_idle_states].flags = CPUIDLE_FLAG_TIMER_STOP; - powernv_states[nr_idle_states].exit_latency = - ((unsigned int)latency_ns) / 1000; - powernv_states[nr_idle_states].target_residency = - ((unsigned int)latency_ns / 100); + powernv_states[nr_idle_states].target_residency = 300000; powernv_states[nr_idle_states].enter = &fastsleep_loop; - nr_idle_states++; } + + powernv_states[nr_idle_states].exit_latency = + ((unsigned int)latency_ns[i]) / 1000; + + if (!rc) { + powernv_states[nr_idle_states].target_residency = + ((unsigned int)residency_ns[i]) / 1000; + } + + nr_idle_states++; } + kfree(residency_ns); +out_free_latency: + kfree(latency_ns); +out: return nr_idle_states; } -- cgit v1.2.3-59-g8ed1b From 70734a786acfd1998e47d40df19cba5c29469bdf Mon Sep 17 00:00:00 2001 From: Preeti U Murthy Date: Wed, 18 Feb 2015 23:24:53 -0600 Subject: cpuidle: powernv: Avoid endianness conversions while parsing DT We currently read the information about idle states from the DT so as to populate the cpuidle table. Use those APIs to read from the DT that can avoid endianness conversions of the property values in the cpuidle driver. Signed-off-by: Preeti U Murthy Acked-by: Michael Ellerman Signed-off-by: Rafael J. Wysocki --- drivers/cpuidle/cpuidle-powernv.c | 29 ++++++++++++++++------------- 1 file changed, 16 insertions(+), 13 deletions(-) (limited to 'drivers/cpuidle') diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c index 30d42298a69f..59372077ec7c 100644 --- a/drivers/cpuidle/cpuidle-powernv.c +++ b/drivers/cpuidle/cpuidle-powernv.c @@ -159,9 +159,7 @@ static int powernv_add_idle_states(void) struct device_node *power_mgt; int nr_idle_states = 1; /* Snooze */ int dt_idle_states; - const __be32 *idle_state_flags; - u32 len_flags, flags; - u32 *latency_ns, *residency_ns; + u32 *latency_ns, *residency_ns, *flags; int i, rc; /* Currently we have snooze statically defined */ @@ -172,14 +170,19 @@ static int powernv_add_idle_states(void) goto out; } - idle_state_flags = of_get_property(power_mgt, - "ibm,cpu-idle-state-flags", &len_flags); - if (!idle_state_flags) { - pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-flags in DT\n"); + /* Read values of any property to determine the num of idle states */ + dt_idle_states = of_property_count_u32_elems(power_mgt, "ibm,cpu-idle-state-flags"); + if (dt_idle_states < 0) { + pr_warn("cpuidle-powernv: no idle states found in the DT\n"); goto out; } - dt_idle_states = len_flags / sizeof(u32); + flags = kzalloc(sizeof(*flags) * dt_idle_states, GFP_KERNEL); + if (of_property_read_u32_array(power_mgt, + "ibm,cpu-idle-state-flags", flags, dt_idle_states)) { + pr_warn("cpuidle-powernv : missing ibm,cpu-idle-state-flags in DT\n"); + goto out_free_flags; + } latency_ns = kzalloc(sizeof(*latency_ns) * dt_idle_states, GFP_KERNEL); rc = of_property_read_u32_array(power_mgt, @@ -195,21 +198,19 @@ static int powernv_add_idle_states(void) for (i = 0; i < dt_idle_states; i++) { - flags = be32_to_cpu(idle_state_flags[i]); - /* * Cpuidle accepts exit_latency and target_residency in us. * Use default target_residency values if f/w does not expose it. */ - if (flags & OPAL_PM_NAP_ENABLED) { + if (flags[i] & OPAL_PM_NAP_ENABLED) { /* Add NAP state */ strcpy(powernv_states[nr_idle_states].name, "Nap"); strcpy(powernv_states[nr_idle_states].desc, "Nap"); powernv_states[nr_idle_states].flags = 0; powernv_states[nr_idle_states].target_residency = 100; powernv_states[nr_idle_states].enter = &nap_loop; - } else if (flags & OPAL_PM_SLEEP_ENABLED || - flags & OPAL_PM_SLEEP_ENABLED_ER1) { + } else if (flags[i] & OPAL_PM_SLEEP_ENABLED || + flags[i] & OPAL_PM_SLEEP_ENABLED_ER1) { /* Add FASTSLEEP state */ strcpy(powernv_states[nr_idle_states].name, "FastSleep"); strcpy(powernv_states[nr_idle_states].desc, "FastSleep"); @@ -232,6 +233,8 @@ static int powernv_add_idle_states(void) kfree(residency_ns); out_free_latency: kfree(latency_ns); +out_free_flags: + kfree(flags); out: return nr_idle_states; } -- cgit v1.2.3-59-g8ed1b