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From f375d3c39d2835929d34c2a046b8c43cea6d1467 Mon Sep 17 00:00:00 2001
From: Santosh Shilimkar <santosh.shilimkar@ti.com>
Date: Mon, 14 Mar 2011 17:08:49 +0530
Subject: [PATCH 7/8] 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@ti.com>
Cc: Kevin Hilman <khilman@ti.com>
cc: Vishwanath BS <vishwanath.bs@ti.com>
---
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 14f84cc..8d472f6 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 __cpuinit 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 __cpuinit 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 __cpuinit 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;
--
1.6.6.1
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