> -----Original Message----- > From: linux-omap-owner@xxxxxxxxxxxxxxx [mailto:linux-omap- > owner@xxxxxxxxxxxxxxx] On Behalf Of Shilimkar, Santosh > Sent: Friday, February 25, 2011 11:41 AM > To: linux-omap@xxxxxxxxxxxxxxx > Cc: Hilman, Kevin; Sripathy, Vishwanath; Shilimkar, Santosh > Subject: [PATCH 3/3] omap2plus: cpufreq: Add SMP support to cater OMAP4430 > > 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 <santosh.shilimkar@xxxxxx> > Cc: Kevin Hilman <khilman@xxxxxx> > cc: Vishwanath BS <vishwanath.bs@xxxxxx> > --- > arch/arm/mach-omap2/omap2plus-cpufreq.c | 71 > ++++++++++++++++++++++++++---- > 1 files changed, 61 insertions(+), 10 deletions(-) > > diff --git a/arch/arm/mach-omap2/omap2plus-cpufreq.c b/arch/arm/mach- > omap2/omap2plus-cpufreq.c > index 48da867..8c903c1 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; > > + /* Wait untill all CPU's are initialized */ Typo: until > + if (is_smp() && (num_online_cpus() < NR_CPUS)) > + return ret; Does it make sense to add pr_info() or pr_warning() before returning? > + > /* 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 > @@ -100,6 +116,7 @@ static int omap_target(struct cpufreq_policy *policy, > ret = clk_set_rate(mpu_clk, freqs.new * 1000); > if (ret) > return ret; > + freqs.new = omap_getspeed(policy->cpu); > > /* > * Generic CPUFREQ driver jiffy update is under !SMP. So jiffies > @@ -107,12 +124,32 @@ static int omap_target(struct cpufreq_policy > *policy, > * CONFIG_SMP enabled. Below code is added only to manage that > * scenario > */ > - if (!is_smp()) > + 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 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; > } > > @@ -120,15 +157,16 @@ static int __init omap_cpu_init(struct > cpufreq_policy *policy) > { > int result = 0; > struct device *mpu_dev; > + static cpumask_var_t cpumask; > > mpu_clk = clk_get(NULL, "cpu_ck"); > 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) { > @@ -150,7 +188,20 @@ 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 builf working. Typo: build > + */ > + 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 majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
