[CPUFREQ] cpumask: avoid playing with cpus_allowed in powernow-k8.c
cpumask: avoid playing with cpus_allowed in powernow-k8.c It's generally a very bad idea to mug some process's cpumask: it could legitimately and reasonably be changed by root, which could break us (if done before our code) or them (if we restore the wrong value). I did not replace powernowk8_target; it needs fixing, but it grabs a mutex (so no smp_call_function_single here) but Mark points out it can be called multiple times per second, so work_on_cpu is too heavy. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> To: cpufreq@vger.kernel.org Acked-by: Mark Langsdorf <mark.langsdorf@amd.com> Tested-by: Mark Langsdorf <mark.langsdorf@amd.com> Signed-off-by: Dave Jones <davej@redhat.com>
This commit is contained in:
Rusty Russell
Dave Jones
Родитель
e3f996c26f
Коммит
1ff6e97f1d
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@ -508,41 +508,34 @@ static int core_voltage_post_transition(struct powernow_k8_data *data,
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return 0;
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}
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static int check_supported_cpu(unsigned int cpu)
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static void check_supported_cpu(void *_rc)
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{
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cpumask_t oldmask;
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u32 eax, ebx, ecx, edx;
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unsigned int rc = 0;
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int *rc = _rc;
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oldmask = current->cpus_allowed;
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set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
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if (smp_processor_id() != cpu) {
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printk(KERN_ERR PFX "limiting to cpu %u failed\n", cpu);
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goto out;
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}
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*rc = -ENODEV;
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if (current_cpu_data.x86_vendor != X86_VENDOR_AMD)
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goto out;
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return;
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eax = cpuid_eax(CPUID_PROCESSOR_SIGNATURE);
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if (((eax & CPUID_XFAM) != CPUID_XFAM_K8) &&
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((eax & CPUID_XFAM) < CPUID_XFAM_10H))
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goto out;
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return;
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if ((eax & CPUID_XFAM) == CPUID_XFAM_K8) {
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if (((eax & CPUID_USE_XFAM_XMOD) != CPUID_USE_XFAM_XMOD) ||
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((eax & CPUID_XMOD) > CPUID_XMOD_REV_MASK)) {
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printk(KERN_INFO PFX
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"Processor cpuid %x not supported\n", eax);
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goto out;
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return;
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}
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eax = cpuid_eax(CPUID_GET_MAX_CAPABILITIES);
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if (eax < CPUID_FREQ_VOLT_CAPABILITIES) {
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printk(KERN_INFO PFX
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"No frequency change capabilities detected\n");
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goto out;
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return;
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}
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cpuid(CPUID_FREQ_VOLT_CAPABILITIES, &eax, &ebx, &ecx, &edx);
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@ -550,21 +543,17 @@ static int check_supported_cpu(unsigned int cpu)
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!= P_STATE_TRANSITION_CAPABLE) {
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printk(KERN_INFO PFX
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"Power state transitions not supported\n");
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goto out;
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return;
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}
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} else { /* must be a HW Pstate capable processor */
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cpuid(CPUID_FREQ_VOLT_CAPABILITIES, &eax, &ebx, &ecx, &edx);
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if ((edx & USE_HW_PSTATE) == USE_HW_PSTATE)
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cpu_family = CPU_HW_PSTATE;
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else
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goto out;
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return;
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}
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rc = 1;
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out:
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set_cpus_allowed_ptr(current, &oldmask);
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return rc;
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*rc = 0;
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}
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static int check_pst_table(struct powernow_k8_data *data, struct pst_s *pst,
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@ -1247,6 +1236,32 @@ static int powernowk8_verify(struct cpufreq_policy *pol)
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return cpufreq_frequency_table_verify(pol, data->powernow_table);
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}
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struct init_on_cpu {
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struct powernow_k8_data *data;
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int rc;
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};
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static void __cpuinit powernowk8_cpu_init_on_cpu(void *_init_on_cpu)
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{
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struct init_on_cpu *init_on_cpu = _init_on_cpu;
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if (pending_bit_stuck()) {
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printk(KERN_ERR PFX "failing init, change pending bit set\n");
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init_on_cpu->rc = -ENODEV;
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return;
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}
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if (query_current_values_with_pending_wait(init_on_cpu->data)) {
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init_on_cpu->rc = -ENODEV;
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return;
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}
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if (cpu_family == CPU_OPTERON)
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fidvid_msr_init();
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init_on_cpu->rc = 0;
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}
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/* per CPU init entry point to the driver */
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static int __cpuinit powernowk8_cpu_init(struct cpufreq_policy *pol)
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{
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@ -1254,13 +1269,14 @@ static int __cpuinit powernowk8_cpu_init(struct cpufreq_policy *pol)
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KERN_ERR FW_BUG PFX "No compatible ACPI _PSS objects found.\n"
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KERN_ERR FW_BUG PFX "Try again with latest BIOS.\n";
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struct powernow_k8_data *data;
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cpumask_t oldmask;
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struct init_on_cpu init_on_cpu;
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int rc;
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if (!cpu_online(pol->cpu))
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return -ENODEV;
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if (!check_supported_cpu(pol->cpu))
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smp_call_function_single(pol->cpu, check_supported_cpu, &rc, 1);
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if (rc)
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return -ENODEV;
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data = kzalloc(sizeof(struct powernow_k8_data), GFP_KERNEL);
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@ -1300,27 +1316,12 @@ static int __cpuinit powernowk8_cpu_init(struct cpufreq_policy *pol)
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pol->cpuinfo.transition_latency = get_transition_latency(data);
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/* only run on specific CPU from here on */
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oldmask = current->cpus_allowed;
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set_cpus_allowed_ptr(current, &cpumask_of_cpu(pol->cpu));
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if (smp_processor_id() != pol->cpu) {
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printk(KERN_ERR PFX "limiting to cpu %u failed\n", pol->cpu);
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goto err_out_unmask;
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}
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if (pending_bit_stuck()) {
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printk(KERN_ERR PFX "failing init, change pending bit set\n");
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goto err_out_unmask;
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}
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if (query_current_values_with_pending_wait(data))
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goto err_out_unmask;
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if (cpu_family == CPU_OPTERON)
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fidvid_msr_init();
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/* run on any CPU again */
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set_cpus_allowed_ptr(current, &oldmask);
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init_on_cpu.data = data;
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smp_call_function_single(data->cpu, powernowk8_cpu_init_on_cpu,
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&init_on_cpu, 1);
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rc = init_on_cpu.rc;
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if (rc != 0)
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goto err_out_exit_acpi;
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if (cpu_family == CPU_HW_PSTATE)
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cpumask_copy(pol->cpus, cpumask_of(pol->cpu));
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@ -1357,8 +1358,7 @@ static int __cpuinit powernowk8_cpu_init(struct cpufreq_policy *pol)
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return 0;
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err_out_unmask:
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set_cpus_allowed_ptr(current, &oldmask);
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err_out_exit_acpi:
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powernow_k8_cpu_exit_acpi(data);
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err_out:
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@ -1383,24 +1383,25 @@ static int __devexit powernowk8_cpu_exit(struct cpufreq_policy *pol)
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return 0;
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}
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static void query_values_on_cpu(void *_err)
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{
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int *err = _err;
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struct powernow_k8_data *data = __get_cpu_var(powernow_data);
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*err = query_current_values_with_pending_wait(data);
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}
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static unsigned int powernowk8_get(unsigned int cpu)
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{
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struct powernow_k8_data *data = per_cpu(powernow_data, cpu);
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cpumask_t oldmask = current->cpus_allowed;
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unsigned int khz = 0;
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int err;
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if (!data)
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return -EINVAL;
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set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
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if (smp_processor_id() != cpu) {
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printk(KERN_ERR PFX
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"limiting to CPU %d failed in powernowk8_get\n", cpu);
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set_cpus_allowed_ptr(current, &oldmask);
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return 0;
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}
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if (query_current_values_with_pending_wait(data))
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smp_call_function_single(cpu, query_values_on_cpu, &err, true);
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if (err)
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goto out;
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if (cpu_family == CPU_HW_PSTATE)
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@ -1411,7 +1412,6 @@ static unsigned int powernowk8_get(unsigned int cpu)
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out:
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set_cpus_allowed_ptr(current, &oldmask);
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return khz;
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}
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@ -1437,7 +1437,9 @@ static int __cpuinit powernowk8_init(void)
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unsigned int i, supported_cpus = 0;
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for_each_online_cpu(i) {
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if (check_supported_cpu(i))
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int rc;
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smp_call_function_single(i, check_supported_cpu, &rc, 1);
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if (rc == 0)
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supported_cpus++;
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}
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