On OMAP SMP configuartion, both processors share the voltage and clock. So both CPUs needs to be scaled together and hence needs software co-ordination.
Signed-off-by: Santosh Shilimkar <[email protected]> Cc: Kevin Hilman <[email protected]> cc: Vishwanath BS <[email protected]> --- arch/arm/mach-omap2/omap2plus-cpufreq.c | 73 ++++++++++++++++++++++++++----- 1 files changed, 62 insertions(+), 11 deletions(-) diff --git a/arch/arm/mach-omap2/omap2plus-cpufreq.c b/arch/arm/mach-omap2/omap2plus-cpufreq.c index 216704e..84caa6d 100644 --- a/arch/arm/mach-omap2/omap2plus-cpufreq.c +++ b/arch/arm/mach-omap2/omap2plus-cpufreq.c @@ -26,9 +26,11 @@ #include <linux/clk.h> #include <linux/io.h> #include <linux/opp.h> +#include <linux/cpu.h> #include <asm/system.h> #include <asm/smp_plat.h> +#include <asm/cpu.h> #include <plat/clock.h> #include <plat/omap-pm.h> @@ -63,7 +65,7 @@ static unsigned int omap_getspeed(unsigned int cpu) { unsigned long rate; - if (cpu) + if (cpu >= NR_CPUS) return 0; rate = clk_get_rate(mpu_clk) / 1000; @@ -74,9 +76,13 @@ static int omap_target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation) { - int ret = 0; + int i, ret = 0; struct cpufreq_freqs freqs; + /* Changes not allowed until all CPUs are online */ + if (is_smp() && (num_online_cpus() < NR_CPUS)) + return ret; + /* Ensure desired rate is within allowed range. Some govenors * (ondemand) will just pass target_freq=0 to get the minimum. */ if (target_freq < policy->min) @@ -84,15 +90,25 @@ static int omap_target(struct cpufreq_policy *policy, if (target_freq > policy->max) target_freq = policy->max; - freqs.old = omap_getspeed(0); + freqs.old = omap_getspeed(policy->cpu); freqs.new = clk_round_rate(mpu_clk, target_freq * 1000) / 1000; - freqs.cpu = 0; + freqs.cpu = policy->cpu; if (freqs.old == freqs.new) return ret; - cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); + if (!is_smp()) { + cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); + goto set_freq; + } + + /* notifiers */ + for_each_cpu(i, policy->cpus) { + freqs.cpu = i; + cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); + } +set_freq: #ifdef CONFIG_CPU_FREQ_DEBUG pr_info("cpufreq-omap: transition: %u --> %u\n", freqs.old, freqs.new); #endif @@ -105,12 +121,33 @@ static int omap_target(struct cpufreq_policy *policy, * CONFIG_SMP enabled. Below code is added only to manage that * scenario */ - if (!is_smp()) + freqs.new = omap_getspeed(policy->cpu); + if (!is_smp()) { loops_per_jiffy = cpufreq_scale(loops_per_jiffy, freqs.old, freqs.new); + cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); + goto skip_lpj; + } - cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); +#ifdef CONFIG_SMP + /* + * Note that loops_per_jiffy is not updated on SMP systems in + * cpufreq driver. So, update the per-CPU loops_per_jiffy value + * on frequency transition. We need to update all dependent CPUs. + */ + for_each_cpu(i, policy->cpus) + per_cpu(cpu_data, i).loops_per_jiffy = + cpufreq_scale(per_cpu(cpu_data, i).loops_per_jiffy, + freqs.old, freqs.new); +#endif + /* notifiers */ + for_each_cpu(i, policy->cpus) { + freqs.cpu = i; + cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); + } + +skip_lpj: return ret; } @@ -118,6 +155,7 @@ static int __init omap_cpu_init(struct cpufreq_policy *policy) { int result = 0; struct device *mpu_dev; + static cpumask_var_t cpumask; if (cpu_is_omap24xx()) mpu_clk = clk_get(NULL, "virt_prcm_set"); @@ -129,12 +167,12 @@ static int __init omap_cpu_init(struct cpufreq_policy *policy) if (IS_ERR(mpu_clk)) return PTR_ERR(mpu_clk); - if (policy->cpu != 0) + if (policy->cpu >= NR_CPUS) return -EINVAL; - policy->cur = policy->min = policy->max = omap_getspeed(0); - + policy->cur = policy->min = policy->max = omap_getspeed(policy->cpu); mpu_dev = omap2_get_mpuss_device(); + if (!mpu_dev) { pr_warning("%s: unable to get the mpu device\n", __func__); return -EINVAL; @@ -154,7 +192,20 @@ static int __init omap_cpu_init(struct cpufreq_policy *policy) policy->min = policy->cpuinfo.min_freq; policy->max = policy->cpuinfo.max_freq; - policy->cur = omap_getspeed(0); + policy->cur = omap_getspeed(policy->cpu); + + /* + * On OMAP SMP configuartion, both processors share the voltage + * and clock. So both CPUs needs to be scaled together and hence + * needs software co-ordination. Use cpufreq affected_cpus + * interface to handle this scenario. Additional is_smp() check + * is to keep SMP_ON_UP build working. + */ + if (is_smp()) { + policy->shared_type = CPUFREQ_SHARED_TYPE_ANY; + cpumask_or(cpumask, cpumask_of(policy->cpu), cpumask); + cpumask_copy(policy->cpus, cpumask); + } /* FIXME: what's the actual transition time? */ policy->cpuinfo.transition_latency = 300 * 1000; -- 1.6.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
