Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq:
  [CPUFREQ] cpumask: new cpumask operators for arch/x86/kernel/cpu/cpufreq/powernow-k8.c
  [CPUFREQ] cpumask: avoid playing with cpus_allowed in powernow-k8.c
  [CPUFREQ] cpumask: avoid cpumask games in arch/x86/kernel/cpu/cpufreq/speedstep-centrino.c
  [CPUFREQ] cpumask: avoid playing with cpus_allowed in speedstep-ich.c
  [CPUFREQ] powernow-k8: get drv data for correct CPU
  [CPUFREQ] powernow-k8: read P-state from HW
  [CPUFREQ] reduce scope of ACPI_PSS_BIOS_BUG_MSG[]
  [CPUFREQ] Clean up convoluted code in arch/x86/kernel/tsc.c:time_cpufreq_notifier()
  [CPUFREQ] minor correction to cpu-freq documentation
  [CPUFREQ] powernow-k8.c: mess cleanup
  [CPUFREQ] Only set sampling_rate_max deprecated, sampling_rate_min is useful
  [CPUFREQ] powernow-k8: Set transition latency to 1 if ACPI tables export 0
  [CPUFREQ] ondemand: Uncouple minimal sampling rate from HZ in NO_HZ case

6 files changed, 175 insertions, 189 deletions

diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
index cf52215d9eb1..81cbe64ed6b4 100644
--- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
@@ -1,3 +1,4 @@
+
 /*
  *   (c) 2003-2006 Advanced Micro Devices, Inc.
  *  Your use of this code is subject to the terms and conditions of the
@@ -117,20 +118,17 @@ static int query_current_values_with_pending_wait(struct powernow_k8_data *data)
         u32 i = 0;
 
         if (cpu_family == CPU_HW_PSTATE) {
-                if (data->currpstate == HW_PSTATE_INVALID) {
-                        /* read (initial) hw pstate if not yet set */
-                        rdmsr(MSR_PSTATE_STATUS, lo, hi);
-                        i = lo & HW_PSTATE_MASK;
-
-                        /*
-                         * a workaround for family 11h erratum 311 might cause
-                         * an "out-of-range Pstate if the core is in Pstate-0
-                         */
-                        if (i >= data->numps)
-                                data->currpstate = HW_PSTATE_0;
-                        else
-                                data->currpstate = i;
-                }
+                rdmsr(MSR_PSTATE_STATUS, lo, hi);
+                i = lo & HW_PSTATE_MASK;
+                data->currpstate = i;
+
+                /*
+                 * a workaround for family 11h erratum 311 might cause
+                 * an "out-of-range Pstate if the core is in Pstate-0
+                 */
+                if ((boot_cpu_data.x86 == 0x11) && (i >= data->numps))
+                        data->currpstate = HW_PSTATE_0;
+
                 return 0;
         }
         do {
@@ -510,41 +508,34 @@ static int core_voltage_post_transition(struct powernow_k8_data *data,
         return 0;
 }
 
-static int check_supported_cpu(unsigned int cpu)
+static void check_supported_cpu(void *_rc)
 {
-        cpumask_t oldmask;
         u32 eax, ebx, ecx, edx;
-        unsigned int rc = 0;
-
-        oldmask = current->cpus_allowed;
-        set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
+        int *rc = _rc;
 
-        if (smp_processor_id() != cpu) {
-                printk(KERN_ERR PFX "limiting to cpu %u failed\n", cpu);
-                goto out;
-        }
+        *rc = -ENODEV;
 
         if (current_cpu_data.x86_vendor != X86_VENDOR_AMD)
-                goto out;
+                return;
 
         eax = cpuid_eax(CPUID_PROCESSOR_SIGNATURE);
         if (((eax & CPUID_XFAM) != CPUID_XFAM_K8) &&
             ((eax & CPUID_XFAM) < CPUID_XFAM_10H))
-                goto out;
+                return;
 
         if ((eax & CPUID_XFAM) == CPUID_XFAM_K8) {
                 if (((eax & CPUID_USE_XFAM_XMOD) != CPUID_USE_XFAM_XMOD) ||
                     ((eax & CPUID_XMOD) > CPUID_XMOD_REV_MASK)) {
                         printk(KERN_INFO PFX
                                 "Processor cpuid %x not supported\n", eax);
-                        goto out;
+                        return;
                 }
 
                 eax = cpuid_eax(CPUID_GET_MAX_CAPABILITIES);
                 if (eax < CPUID_FREQ_VOLT_CAPABILITIES) {
                         printk(KERN_INFO PFX
                                "No frequency change capabilities detected\n");
-                        goto out;
+                        return;
                 }
 
                 cpuid(CPUID_FREQ_VOLT_CAPABILITIES, &eax, &ebx, &ecx, &edx);
@@ -552,21 +543,17 @@ static int check_supported_cpu(unsigned int cpu)
                         != P_STATE_TRANSITION_CAPABLE) {
                         printk(KERN_INFO PFX
                                 "Power state transitions not supported\n");
-                        goto out;
+                        return;
                 }
         } else { /* must be a HW Pstate capable processor */
                 cpuid(CPUID_FREQ_VOLT_CAPABILITIES, &eax, &ebx, &ecx, &edx);
                 if ((edx & USE_HW_PSTATE) == USE_HW_PSTATE)
                         cpu_family = CPU_HW_PSTATE;
                 else
-                        goto out;
+                        return;
         }
 
-        rc = 1;
-
-out:
-        set_cpus_allowed_ptr(current, &oldmask);
-        return rc;
+        *rc = 0;
 }
 
 static int check_pst_table(struct powernow_k8_data *data, struct pst_s *pst,
@@ -823,13 +810,14 @@ static void powernow_k8_acpi_pst_values(struct powernow_k8_data *data,
         if (!data->acpi_data.state_count || (cpu_family == CPU_HW_PSTATE))
                 return;
 
-        control = data->acpi_data.states[index].control; data->irt = (control
-                        >> IRT_SHIFT) & IRT_MASK; data->rvo = (control >>
-                                RVO_SHIFT) & RVO_MASK; data->exttype = (control
-                                        >> EXT_TYPE_SHIFT) & EXT_TYPE_MASK;
-        data->plllock = (control >> PLL_L_SHIFT) & PLL_L_MASK; data->vidmvs = 1
-                << ((control >> MVS_SHIFT) & MVS_MASK); data->vstable =
-                (control >> VST_SHIFT) & VST_MASK; }
+        control = data->acpi_data.states[index].control;
+        data->irt = (control >> IRT_SHIFT) & IRT_MASK;
+        data->rvo = (control >> RVO_SHIFT) & RVO_MASK;
+        data->exttype = (control >> EXT_TYPE_SHIFT) & EXT_TYPE_MASK;
+        data->plllock = (control >> PLL_L_SHIFT) & PLL_L_MASK;
+        data->vidmvs = 1 << ((control >> MVS_SHIFT) & MVS_MASK);
+        data->vstable = (control >> VST_SHIFT) & VST_MASK;
+}
 
 static int powernow_k8_cpu_init_acpi(struct powernow_k8_data *data)
 {
@@ -1046,6 +1034,19 @@ static int get_transition_latency(struct powernow_k8_data *data)
                 if (cur_latency > max_latency)
                         max_latency = cur_latency;
         }
+        if (max_latency == 0) {
+                /*
+                 * Fam 11h always returns 0 as transition latency.
+                 * This is intended and means "very fast". While cpufreq core
+                 * and governors currently can handle that gracefully, better
+                 * set it to 1 to avoid problems in the future.
+                 * For all others it's a BIOS bug.
+                 */
+                if (!boot_cpu_data.x86 == 0x11)
+                        printk(KERN_ERR FW_WARN PFX "Invalid zero transition "
+                                "latency\n");
+                max_latency = 1;
+        }
         /* value in usecs, needs to be in nanoseconds */
         return 1000 * max_latency;
 }
@@ -1093,7 +1094,7 @@ static int transition_frequency_fidvid(struct powernow_k8_data *data,
         freqs.old = find_khz_freq_from_fid(data->currfid);
         freqs.new = find_khz_freq_from_fid(fid);
 
-        for_each_cpu_mask_nr(i, *(data->available_cores)) {
+        for_each_cpu(i, data->available_cores) {
                 freqs.cpu = i;
                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
         }
@@ -1101,7 +1102,7 @@ static int transition_frequency_fidvid(struct powernow_k8_data *data,
         res = transition_fid_vid(data, fid, vid);
         freqs.new = find_khz_freq_from_fid(data->currfid);
 
-        for_each_cpu_mask_nr(i, *(data->available_cores)) {
+        for_each_cpu(i, data->available_cores) {
                 freqs.cpu = i;
                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
         }
@@ -1126,7 +1127,7 @@ static int transition_frequency_pstate(struct powernow_k8_data *data,
                         data->currpstate);
         freqs.new = find_khz_freq_from_pstate(data->powernow_table, pstate);
 
-        for_each_cpu_mask_nr(i, *(data->available_cores)) {
+        for_each_cpu(i, data->available_cores) {
                 freqs.cpu = i;
                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
         }
@@ -1134,7 +1135,7 @@ static int transition_frequency_pstate(struct powernow_k8_data *data,
         res = transition_pstate(data, pstate);
         freqs.new = find_khz_freq_from_pstate(data->powernow_table, pstate);
 
-        for_each_cpu_mask_nr(i, *(data->available_cores)) {
+        for_each_cpu(i, data->available_cores) {
                 freqs.cpu = i;
                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
         }
@@ -1235,21 +1236,47 @@ static int powernowk8_verify(struct cpufreq_policy *pol)
         return cpufreq_frequency_table_verify(pol, data->powernow_table);
 }
 
-static const char ACPI_PSS_BIOS_BUG_MSG[] =
-        KERN_ERR FW_BUG PFX "No compatible ACPI _PSS objects found.\n"
-        KERN_ERR FW_BUG PFX "Try again with latest BIOS.\n";
+struct init_on_cpu {
+        struct powernow_k8_data *data;
+        int rc;
+};
+
+static void __cpuinit powernowk8_cpu_init_on_cpu(void *_init_on_cpu)
+{
+        struct init_on_cpu *init_on_cpu = _init_on_cpu;
+
+        if (pending_bit_stuck()) {
+                printk(KERN_ERR PFX "failing init, change pending bit set\n");
+                init_on_cpu->rc = -ENODEV;
+                return;
+        }
+
+        if (query_current_values_with_pending_wait(init_on_cpu->data)) {
+                init_on_cpu->rc = -ENODEV;
+                return;
+        }
+
+        if (cpu_family == CPU_OPTERON)
+                fidvid_msr_init();
+
+        init_on_cpu->rc = 0;
+}
 
 /* per CPU init entry point to the driver */
 static int __cpuinit powernowk8_cpu_init(struct cpufreq_policy *pol)
 {
+        static const char ACPI_PSS_BIOS_BUG_MSG[] =
+                KERN_ERR FW_BUG PFX "No compatible ACPI _PSS objects found.\n"
+                KERN_ERR FW_BUG PFX "Try again with latest BIOS.\n";
         struct powernow_k8_data *data;
-        cpumask_t oldmask;
+        struct init_on_cpu init_on_cpu;
         int rc;
 
         if (!cpu_online(pol->cpu))
                 return -ENODEV;
 
-        if (!check_supported_cpu(pol->cpu))
+        smp_call_function_single(pol->cpu, check_supported_cpu, &rc, 1);
+        if (rc)
                 return -ENODEV;
 
         data = kzalloc(sizeof(struct powernow_k8_data), GFP_KERNEL);
@@ -1289,27 +1316,12 @@ static int __cpuinit powernowk8_cpu_init(struct cpufreq_policy *pol)
                 pol->cpuinfo.transition_latency = get_transition_latency(data);
 
         /* only run on specific CPU from here on */
-        oldmask = current->cpus_allowed;
-        set_cpus_allowed_ptr(current, &cpumask_of_cpu(pol->cpu));
-
-        if (smp_processor_id() != pol->cpu) {
-                printk(KERN_ERR PFX "limiting to cpu %u failed\n", pol->cpu);
-                goto err_out_unmask;
-        }
-
-        if (pending_bit_stuck()) {
-                printk(KERN_ERR PFX "failing init, change pending bit set\n");
-                goto err_out_unmask;
-        }
-
-        if (query_current_values_with_pending_wait(data))
-                goto err_out_unmask;
-
-        if (cpu_family == CPU_OPTERON)
-                fidvid_msr_init();
-
-        /* run on any CPU again */
-        set_cpus_allowed_ptr(current, &oldmask);
+        init_on_cpu.data = data;
+        smp_call_function_single(data->cpu, powernowk8_cpu_init_on_cpu,
+                                 &init_on_cpu, 1);
+        rc = init_on_cpu.rc;
+        if (rc != 0)
+                goto err_out_exit_acpi;
 
         if (cpu_family == CPU_HW_PSTATE)
                 cpumask_copy(pol->cpus, cpumask_of(pol->cpu));
@@ -1346,8 +1358,7 @@ static int __cpuinit powernowk8_cpu_init(struct cpufreq_policy *pol)
 
         return 0;
 
-err_out_unmask:
-        set_cpus_allowed_ptr(current, &oldmask);
+err_out_exit_acpi:
         powernow_k8_cpu_exit_acpi(data);
 
 err_out:
@@ -1372,28 +1383,25 @@ static int __devexit powernowk8_cpu_exit(struct cpufreq_policy *pol)
         return 0;
 }
 
+static void query_values_on_cpu(void *_err)
+{
+        int *err = _err;
+        struct powernow_k8_data *data = __get_cpu_var(powernow_data);
+
+        *err = query_current_values_with_pending_wait(data);
+}
+
 static unsigned int powernowk8_get(unsigned int cpu)
 {
-        struct powernow_k8_data *data;
-        cpumask_t oldmask = current->cpus_allowed;
+        struct powernow_k8_data *data = per_cpu(powernow_data, cpu);
         unsigned int khz = 0;
-        unsigned int first;
-
-        first = cpumask_first(cpu_core_mask(cpu));
-        data = per_cpu(powernow_data, first);
+        int err;
 
         if (!data)
                 return -EINVAL;
 
-        set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
-        if (smp_processor_id() != cpu) {
-                printk(KERN_ERR PFX
-                        "limiting to CPU %d failed in powernowk8_get\n", cpu);
-                set_cpus_allowed_ptr(current, &oldmask);
-                return 0;
-        }
-
-        if (query_current_values_with_pending_wait(data))
+        smp_call_function_single(cpu, query_values_on_cpu, &err, true);
+        if (err)
                 goto out;
 
         if (cpu_family == CPU_HW_PSTATE)
@@ -1404,7 +1412,6 @@ static unsigned int powernowk8_get(unsigned int cpu)
 
 
 out:
-        set_cpus_allowed_ptr(current, &oldmask);
         return khz;
 }
 
@@ -1430,7 +1437,9 @@ static int __cpuinit powernowk8_init(void)
         unsigned int i, supported_cpus = 0;
 
         for_each_online_cpu(i) {
-                if (check_supported_cpu(i))
+                int rc;
+                smp_call_function_single(i, check_supported_cpu, &rc, 1);
+                if (rc == 0)
                         supported_cpus++;
         }
 
diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.h b/arch/x86/kernel/cpu/cpufreq/powernow-k8.h
index 6c6698feade1..c9c1190b5e1f 100644
--- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.h
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.h
@@ -223,14 +223,3 @@ static void powernow_k8_acpi_pst_values(struct powernow_k8_data *data, unsigned
 
 static int fill_powernow_table_pstate(struct powernow_k8_data *data, struct cpufreq_frequency_table *powernow_table);
 static int fill_powernow_table_fidvid(struct powernow_k8_data *data, struct cpufreq_frequency_table *powernow_table);
-
-#ifdef CONFIG_SMP
-static inline void define_siblings(int cpu, cpumask_t cpu_sharedcore_mask[])
-{
-}
-#else
-static inline void define_siblings(int cpu, cpumask_t cpu_sharedcore_mask[])
-{
-        cpu_set(0, cpu_sharedcore_mask[0]);
-}
-#endif
diff --git a/arch/x86/kernel/cpu/cpufreq/speedstep-centrino.c b/arch/x86/kernel/cpu/cpufreq/speedstep-centrino.c
index 55c831ed71ce..8d672ef162ce 100644
--- a/arch/x86/kernel/cpu/cpufreq/speedstep-centrino.c
+++ b/arch/x86/kernel/cpu/cpufreq/speedstep-centrino.c
@@ -323,14 +323,8 @@ static unsigned int get_cur_freq(unsigned int cpu)
 {
         unsigned l, h;
         unsigned clock_freq;
-        cpumask_t saved_mask;
 
-        saved_mask = current->cpus_allowed;
-        set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
-        if (smp_processor_id() != cpu)
-                return 0;
-
-        rdmsr(MSR_IA32_PERF_STATUS, l, h);
+        rdmsr_on_cpu(cpu, MSR_IA32_PERF_STATUS, &l, &h);
         clock_freq = extract_clock(l, cpu, 0);
 
         if (unlikely(clock_freq == 0)) {
@@ -340,11 +334,9 @@ static unsigned int get_cur_freq(unsigned int cpu)
                  * P-state transition (like TM2). Get the last freq set 
                  * in PERF_CTL.
                  */
-                rdmsr(MSR_IA32_PERF_CTL, l, h);
+                rdmsr_on_cpu(cpu, MSR_IA32_PERF_CTL, &l, &h);
                 clock_freq = extract_clock(l, cpu, 1);
         }
-
-        set_cpus_allowed_ptr(current, &saved_mask);
         return clock_freq;
 }
 
@@ -467,15 +459,10 @@ static int centrino_target (struct cpufreq_policy *policy,
         struct cpufreq_freqs    freqs;
         int                     retval = 0;
         unsigned int            j, k, first_cpu, tmp;
-        cpumask_var_t saved_mask, covered_cpus;
+        cpumask_var_t covered_cpus;
 
-        if (unlikely(!alloc_cpumask_var(&saved_mask, GFP_KERNEL)))
-                return -ENOMEM;
-        if (unlikely(!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL))) {
-                free_cpumask_var(saved_mask);
+        if (unlikely(!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL)))
                 return -ENOMEM;
-        }
-        cpumask_copy(saved_mask, &current->cpus_allowed);
 
         if (unlikely(per_cpu(centrino_model, cpu) == NULL)) {
                 retval = -ENODEV;
@@ -493,7 +480,7 @@ static int centrino_target (struct cpufreq_policy *policy,
 
         first_cpu = 1;
         for_each_cpu(j, policy->cpus) {
-                const struct cpumask *mask;
+                int good_cpu;
 
                 /* cpufreq holds the hotplug lock, so we are safe here */
                 if (!cpu_online(j))
@@ -504,32 +491,30 @@ static int centrino_target (struct cpufreq_policy *policy,
                  * Make sure we are running on CPU that wants to change freq
                  */
                 if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY)
-                        mask = policy->cpus;
+                        good_cpu = cpumask_any_and(policy->cpus,
+                                                   cpu_online_mask);
                 else
-                        mask = cpumask_of(j);
+                        good_cpu = j;
 
-                set_cpus_allowed_ptr(current, mask);
-                preempt_disable();
-                if (unlikely(!cpu_isset(smp_processor_id(), *mask))) {
+                if (good_cpu >= nr_cpu_ids) {
                         dprintk("couldn't limit to CPUs in this domain\n");
                         retval = -EAGAIN;
                         if (first_cpu) {
                                 /* We haven't started the transition yet. */
-                                goto migrate_end;
+                                goto out;
                         }
-                        preempt_enable();
                         break;
                 }
 
                 msr = per_cpu(centrino_model, cpu)->op_points[newstate].index;
 
                 if (first_cpu) {
-                        rdmsr(MSR_IA32_PERF_CTL, oldmsr, h);
+                        rdmsr_on_cpu(good_cpu, MSR_IA32_PERF_CTL, &oldmsr, &h);
                         if (msr == (oldmsr & 0xffff)) {
                                 dprintk("no change needed - msr was and needs "
                                         "to be %x\n", oldmsr);
                                 retval = 0;
-                                goto migrate_end;
+                                goto out;
                         }
 
                         freqs.old = extract_clock(oldmsr, cpu, 0);
@@ -553,14 +538,11 @@ static int centrino_target (struct cpufreq_policy *policy,
                         oldmsr |= msr;
                 }
 
-                wrmsr(MSR_IA32_PERF_CTL, oldmsr, h);
-                if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
-                        preempt_enable();
+                wrmsr_on_cpu(good_cpu, MSR_IA32_PERF_CTL, oldmsr, h);
+                if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY)
                         break;
-                }
 
-                cpu_set(j, *covered_cpus);
-                preempt_enable();
+                cpumask_set_cpu(j, covered_cpus);
         }
 
         for_each_cpu(k, policy->cpus) {
@@ -578,10 +560,8 @@ static int centrino_target (struct cpufreq_policy *policy,
                  * Best effort undo..
                  */
 
-                for_each_cpu_mask_nr(j, *covered_cpus) {
-                        set_cpus_allowed_ptr(current, &cpumask_of_cpu(j));
-                        wrmsr(MSR_IA32_PERF_CTL, oldmsr, h);
-                }
+                for_each_cpu(j, covered_cpus)
+                        wrmsr_on_cpu(j, MSR_IA32_PERF_CTL, oldmsr, h);
 
                 tmp = freqs.new;
                 freqs.new = freqs.old;
@@ -593,15 +573,9 @@ static int centrino_target (struct cpufreq_policy *policy,
                         cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
                 }
         }
-        set_cpus_allowed_ptr(current, saved_mask);
         retval = 0;
-        goto out;
 
-migrate_end:
-        preempt_enable();
-        set_cpus_allowed_ptr(current, saved_mask);
 out:
-        free_cpumask_var(saved_mask);
         free_cpumask_var(covered_cpus);
         return retval;
 }
diff --git a/arch/x86/kernel/cpu/cpufreq/speedstep-ich.c b/arch/x86/kernel/cpu/cpufreq/speedstep-ich.c
index 016c1a4fa3fc..6911e91fb4f6 100644
--- a/arch/x86/kernel/cpu/cpufreq/speedstep-ich.c
+++ b/arch/x86/kernel/cpu/cpufreq/speedstep-ich.c
@@ -89,7 +89,8 @@ static int speedstep_find_register(void)
  * speedstep_set_state - set the SpeedStep state
  * @state: new processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH)
  *
- *   Tries to change the SpeedStep state.
+ *   Tries to change the SpeedStep state.  Can be called from
+ *   smp_call_function_single.
  */
 static void speedstep_set_state(unsigned int state)
 {
@@ -143,6 +144,11 @@ static void speedstep_set_state(unsigned int state)
         return;
 }
 
+/* Wrapper for smp_call_function_single. */
+static void _speedstep_set_state(void *_state)
+{
+        speedstep_set_state(*(unsigned int *)_state);
+}
 
 /**
  * speedstep_activate - activate SpeedStep control in the chipset
@@ -226,22 +232,28 @@ static unsigned int speedstep_detect_chipset(void)
         return 0;
 }
 
-static unsigned int _speedstep_get(const struct cpumask *cpus)
-{
+struct get_freq_data {
         unsigned int speed;
-        cpumask_t cpus_allowed;
-
-        cpus_allowed = current->cpus_allowed;
-        set_cpus_allowed_ptr(current, cpus);
-        speed = speedstep_get_frequency(speedstep_processor);
-        set_cpus_allowed_ptr(current, &cpus_allowed);
-        dprintk("detected %u kHz as current frequency\n", speed);
-        return speed;
+        unsigned int processor;
+};
+
+static void get_freq_data(void *_data)
+{
+        struct get_freq_data *data = _data;
+
+        data->speed = speedstep_get_frequency(data->processor);
 }
 
 static unsigned int speedstep_get(unsigned int cpu)
 {
-        return _speedstep_get(cpumask_of(cpu));
+        struct get_freq_data data = { .processor = cpu };
+
+        /* You're supposed to ensure CPU is online. */
+        if (smp_call_function_single(cpu, get_freq_data, &data, 1) != 0)
+                BUG();
+
+        dprintk("detected %u kHz as current frequency\n", data.speed);
+        return data.speed;
 }
 
 /**
@@ -257,16 +269,16 @@ static int speedstep_target(struct cpufreq_policy *policy,
                              unsigned int target_freq,
                              unsigned int relation)
 {
-        unsigned int newstate = 0;
+        unsigned int newstate = 0, policy_cpu;
         struct cpufreq_freqs freqs;
-        cpumask_t cpus_allowed;
         int i;
 
         if (cpufreq_frequency_table_target(policy, &speedstep_freqs[0],
                                 target_freq, relation, &newstate))
                 return -EINVAL;
 
-        freqs.old = _speedstep_get(policy->cpus);
+        policy_cpu = cpumask_any_and(policy->cpus, cpu_online_mask);
+        freqs.old = speedstep_get(policy_cpu);
         freqs.new = speedstep_freqs[newstate].frequency;
         freqs.cpu = policy->cpu;
 
@@ -276,20 +288,13 @@ static int speedstep_target(struct cpufreq_policy *policy,
         if (freqs.old == freqs.new)
                 return 0;
 
-        cpus_allowed = current->cpus_allowed;
-
         for_each_cpu(i, policy->cpus) {
                 freqs.cpu = i;
                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
         }
 
-        /* switch to physical CPU where state is to be changed */
-        set_cpus_allowed_ptr(current, policy->cpus);
-
-        speedstep_set_state(newstate);
-
-        /* allow to be run on all CPUs */
-        set_cpus_allowed_ptr(current, &cpus_allowed);
+        smp_call_function_single(policy_cpu, _speedstep_set_state, &newstate,
+                                 true);
 
         for_each_cpu(i, policy->cpus) {
                 freqs.cpu = i;
@@ -312,33 +317,43 @@ static int speedstep_verify(struct cpufreq_policy *policy)
         return cpufreq_frequency_table_verify(policy, &speedstep_freqs[0]);
 }
 
+struct get_freqs {
+        struct cpufreq_policy *policy;
+        int ret;
+};
+
+static void get_freqs_on_cpu(void *_get_freqs)
+{
+        struct get_freqs *get_freqs = _get_freqs;
+
+        get_freqs->ret =
+                speedstep_get_freqs(speedstep_processor,
+                            &speedstep_freqs[SPEEDSTEP_LOW].frequency,
+                            &speedstep_freqs[SPEEDSTEP_HIGH].frequency,
+                            &get_freqs->policy->cpuinfo.transition_latency,
+                            &speedstep_set_state);
+}
 
 static int speedstep_cpu_init(struct cpufreq_policy *policy)
 {
-        int result = 0;
-        unsigned int speed;
-        cpumask_t cpus_allowed;
+        int result;
+        unsigned int policy_cpu, speed;
+        struct get_freqs gf;
 
         /* only run on CPU to be set, or on its sibling */
 #ifdef CONFIG_SMP
         cpumask_copy(policy->cpus, cpu_sibling_mask(policy->cpu));
 #endif
-
-        cpus_allowed = current->cpus_allowed;
-        set_cpus_allowed_ptr(current, policy->cpus);
+        policy_cpu = cpumask_any_and(policy->cpus, cpu_online_mask);
 
         /* detect low and high frequency and transition latency */
-        result = speedstep_get_freqs(speedstep_processor,
-                                     &speedstep_freqs[SPEEDSTEP_LOW].frequency,
-                                     &speedstep_freqs[SPEEDSTEP_HIGH].frequency,
-                                     &policy->cpuinfo.transition_latency,
-                                     &speedstep_set_state);
-        set_cpus_allowed_ptr(current, &cpus_allowed);
-        if (result)
-                return result;
+        gf.policy = policy;
+        smp_call_function_single(policy_cpu, get_freqs_on_cpu, &gf, 1);
+        if (gf.ret)
+                return gf.ret;
 
         /* get current speed setting */
-        speed = _speedstep_get(policy->cpus);
+        speed = speedstep_get(policy_cpu);
         if (!speed)
                 return -EIO;
 
diff --git a/arch/x86/kernel/cpu/cpufreq/speedstep-lib.c b/arch/x86/kernel/cpu/cpufreq/speedstep-lib.c
index 2e3c6862657b..f4c290b8482f 100644
--- a/arch/x86/kernel/cpu/cpufreq/speedstep-lib.c
+++ b/arch/x86/kernel/cpu/cpufreq/speedstep-lib.c
@@ -226,6 +226,7 @@ static unsigned int pentium4_get_frequency(void)
 }
 
 
+/* Warning: may get called from smp_call_function_single. */
 unsigned int speedstep_get_frequency(unsigned int processor)
 {
         switch (processor) {
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index ae3180c506a6..b0597ad02c93 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -632,17 +632,15 @@ static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
                                 void *data)
 {
         struct cpufreq_freqs *freq = data;
-        unsigned long *lpj, dummy;
+        unsigned long *lpj;
 
         if (cpu_has(&cpu_data(freq->cpu), X86_FEATURE_CONSTANT_TSC))
                 return 0;
 
-        lpj = &dummy;
-        if (!(freq->flags & CPUFREQ_CONST_LOOPS))
+        lpj = &boot_cpu_data.loops_per_jiffy;
 #ifdef CONFIG_SMP
+        if (!(freq->flags & CPUFREQ_CONST_LOOPS))
                 lpj = &cpu_data(freq->cpu).loops_per_jiffy;
-#else
-        lpj = &boot_cpu_data.loops_per_jiffy;
 #endif
 
         if (!ref_freq) {