From 70734a786acfd1998e47d40df19cba5c29469bdf Mon Sep 17 00:00:00 2001 From: Preeti U Murthy Date: Wed, 18 Feb 2015 23:24:53 -0600 Subject: [PATCH] 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(-) diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c index 30d4229..5937207 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; } -- 2.7.4