P-state software coordination for acpi-cpufreq

http://bugzilla.kernel.org/show_bug.cgi?id=5737

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 197 insertions, 88 deletions

diff --git a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
index 3852d0a4c1b5..4c7c6e089e87 100644
--- a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -48,12 +48,13 @@ MODULE_LICENSE("GPL");
 
 
 struct cpufreq_acpi_io {
-        struct acpi_processor_performance       acpi_data;
+        struct acpi_processor_performance       *acpi_data;
         struct cpufreq_frequency_table          *freq_table;
         unsigned int                            resume;
 };
 
 static struct cpufreq_acpi_io   *acpi_io_data[NR_CPUS];
+static struct acpi_processor_performance        *acpi_perf_data[NR_CPUS];
 
 static struct cpufreq_driver acpi_cpufreq_driver;
 
@@ -104,64 +105,43 @@ acpi_processor_set_performance (
 {
         u16                     port = 0;
         u8                      bit_width = 0;
+        int                     i = 0;
         int                     ret = 0;
         u32                     value = 0;
-        int                     i = 0;
-        struct cpufreq_freqs    cpufreq_freqs;
-        cpumask_t               saved_mask;
         int                     retval;
+        struct acpi_processor_performance       *perf;
 
         dprintk("acpi_processor_set_performance\n");
 
-        /*
-         * TBD: Use something other than set_cpus_allowed.
-         * As set_cpus_allowed is a bit racy, 
-         * with any other set_cpus_allowed for this process.
-         */
-        saved_mask = current->cpus_allowed;
-        set_cpus_allowed(current, cpumask_of_cpu(cpu));
-        if (smp_processor_id() != cpu) {
-                return (-EAGAIN);
-        }
-        
-        if (state == data->acpi_data.state) {
+        retval = 0;
+        perf = data->acpi_data; 
+        if (state == perf->state) {
                 if (unlikely(data->resume)) {
                         dprintk("Called after resume, resetting to P%d\n", state);
                         data->resume = 0;
                 } else {
                         dprintk("Already at target state (P%d)\n", state);
-                        retval = 0;
-                        goto migrate_end;
+                        return (retval);
                 }
         }
 
-        dprintk("Transitioning from P%d to P%d\n",
-                data->acpi_data.state, state);
-
-        /* cpufreq frequency struct */
-        cpufreq_freqs.cpu = cpu;
-        cpufreq_freqs.old = data->freq_table[data->acpi_data.state].frequency;
-        cpufreq_freqs.new = data->freq_table[state].frequency;
-
-        /* notify cpufreq */
-        cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);
+        dprintk("Transitioning from P%d to P%d\n", perf->state, state);
 
         /*
          * First we write the target state's 'control' value to the
          * control_register.
          */
 
-        port = data->acpi_data.control_register.address;
-        bit_width = data->acpi_data.control_register.bit_width;
-        value = (u32) data->acpi_data.states[state].control;
+        port = perf->control_register.address;
+        bit_width = perf->control_register.bit_width;
+        value = (u32) perf->states[state].control;
 
         dprintk("Writing 0x%08x to port 0x%04x\n", value, port);
 
         ret = acpi_processor_write_port(port, bit_width, value);
         if (ret) {
                 dprintk("Invalid port width 0x%04x\n", bit_width);
-                retval = ret;
-                goto migrate_end;
+                return (ret);
         }
 
         /*
@@ -177,49 +157,36 @@ acpi_processor_set_performance (
                  * before giving up.
                  */
 
-                port = data->acpi_data.status_register.address;
-                bit_width = data->acpi_data.status_register.bit_width;
+                port = perf->status_register.address;
+                bit_width = perf->status_register.bit_width;
 
                 dprintk("Looking for 0x%08x from port 0x%04x\n",
-                        (u32) data->acpi_data.states[state].status, port);
+                        (u32) perf->states[state].status, port);
 
-                for (i=0; i<100; i++) {
+                for (i = 0; i < 100; i++) {
                         ret = acpi_processor_read_port(port, bit_width, &value);
                         if (ret) {      
                                 dprintk("Invalid port width 0x%04x\n", bit_width);
-                                retval = ret;
-                                goto migrate_end;
+                                return (ret);
                         }
-                        if (value == (u32) data->acpi_data.states[state].status)
+                        if (value == (u32) perf->states[state].status)
                                 break;
                         udelay(10);
                 }
         } else {
                 i = 0;
-                value = (u32) data->acpi_data.states[state].status;
+                value = (u32) perf->states[state].status;
         }
 
-        /* notify cpufreq */
-        cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
-
-        if (unlikely(value != (u32) data->acpi_data.states[state].status)) {
-                unsigned int tmp = cpufreq_freqs.new;
-                cpufreq_freqs.new = cpufreq_freqs.old;
-                cpufreq_freqs.old = tmp;
-                cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);
-                cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
+        if (unlikely(value != (u32) perf->states[state].status)) {
                 printk(KERN_WARNING "acpi-cpufreq: Transition failed\n");
                 retval = -ENODEV;
-                goto migrate_end;
+                return (retval);
         }
 
         dprintk("Transition successful after %d microseconds\n", i * 10);
 
-        data->acpi_data.state = state;
-
-        retval = 0;
-migrate_end:
-        set_cpus_allowed(current, saved_mask);
+        perf->state = state;
         return (retval);
 }
 
@@ -231,8 +198,17 @@ acpi_cpufreq_target (
         unsigned int relation)
 {
         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
+        struct acpi_processor_performance *perf;
+        struct cpufreq_freqs freqs;
+        cpumask_t online_policy_cpus;
+        cpumask_t saved_mask;
+        cpumask_t set_mask;
+        cpumask_t covered_cpus;
+        unsigned int cur_state = 0;
         unsigned int next_state = 0;
         unsigned int result = 0;
+        unsigned int j;
+        unsigned int tmp;
 
         dprintk("acpi_cpufreq_setpolicy\n");
 
@@ -241,11 +217,91 @@ acpi_cpufreq_target (
                         target_freq,
                         relation,
                         &next_state);
-        if (result)
+        if (unlikely(result))
                 return (result);
 
-        result = acpi_processor_set_performance (data, policy->cpu, next_state);
+        perf = data->acpi_data;
+        cur_state = perf->state;
+        freqs.old = data->freq_table[cur_state].frequency;
+        freqs.new = data->freq_table[next_state].frequency;
+
+        /* cpufreq holds the hotplug lock, so we are safe from here on */
+        cpus_and(online_policy_cpus, cpu_online_map, policy->cpus);
 
+        for_each_cpu_mask(j, online_policy_cpus) {
+                freqs.cpu = j;
+                cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+        }
+
+        /*
+         * We need to call driver->target() on all or any CPU in
+         * policy->cpus, depending on policy->shared_type.
+         */
+        saved_mask = current->cpus_allowed;
+        cpus_clear(covered_cpus);
+        for_each_cpu_mask(j, online_policy_cpus) {
+                /*
+                 * Support for SMP systems.
+                 * Make sure we are running on CPU that wants to change freq
+                 */
+                cpus_clear(set_mask);
+                if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY)
+                        cpus_or(set_mask, set_mask, online_policy_cpus);
+                else
+                        cpu_set(j, set_mask);
+
+                set_cpus_allowed(current, set_mask);
+                if (unlikely(!cpu_isset(smp_processor_id(), set_mask))) {
+                        dprintk("couldn't limit to CPUs in this domain\n");
+                        result = -EAGAIN;
+                        break;
+                }
+
+                result = acpi_processor_set_performance (data, j, next_state);
+                if (result) {
+                        result = -EAGAIN;
+                        break;
+                }
+
+                if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY)
+                        break;
+ 
+                cpu_set(j, covered_cpus);
+        }
+
+        for_each_cpu_mask(j, online_policy_cpus) {
+                freqs.cpu = j;
+                cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+        }
+
+        if (unlikely(result)) {
+                /*
+                 * We have failed halfway through the frequency change.
+                 * We have sent callbacks to online_policy_cpus and
+                 * acpi_processor_set_performance() has been called on 
+                 * coverd_cpus. Best effort undo..
+                 */
+
+                if (!cpus_empty(covered_cpus)) {
+                        for_each_cpu_mask(j, covered_cpus) {
+                                policy->cpu = j;
+                                acpi_processor_set_performance (data, 
+                                                j, 
+                                                cur_state);
+                        }
+                }
+
+                tmp = freqs.new;
+                freqs.new = freqs.old;
+                freqs.old = tmp;
+                for_each_cpu_mask(j, online_policy_cpus) {
+                        freqs.cpu = j;
+                        cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+                        cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+                }
+        }
+
+        set_cpus_allowed(current, saved_mask);
         return (result);
 }
 
@@ -271,30 +327,65 @@ acpi_cpufreq_guess_freq (
         struct cpufreq_acpi_io  *data,
         unsigned int            cpu)
 {
+        struct acpi_processor_performance       *perf = data->acpi_data;
+
         if (cpu_khz) {
                 /* search the closest match to cpu_khz */
                 unsigned int i;
                 unsigned long freq;
-                unsigned long freqn = data->acpi_data.states[0].core_frequency * 1000;
+                unsigned long freqn = perf->states[0].core_frequency * 1000;
 
-                for (i=0; i < (data->acpi_data.state_count - 1); i++) {
+                for (i = 0; i < (perf->state_count - 1); i++) {
                         freq = freqn;
-                        freqn = data->acpi_data.states[i+1].core_frequency * 1000;
+                        freqn = perf->states[i+1].core_frequency * 1000;
                         if ((2 * cpu_khz) > (freqn + freq)) {
-                                data->acpi_data.state = i;
+                                perf->state = i;
                                 return (freq);
                         }
                 }
-                data->acpi_data.state = data->acpi_data.state_count - 1;
+                perf->state = perf->state_count - 1;
                 return (freqn);
-        } else
+        } else {
                 /* assume CPU is at P0... */
-                data->acpi_data.state = 0;
-                return data->acpi_data.states[0].core_frequency * 1000;
-        
+                perf->state = 0;
+                return perf->states[0].core_frequency * 1000;
+        }
 }
 
 
+/*
+ * acpi_cpufreq_early_init - initialize ACPI P-States library
+ *
+ * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
+ * in order to determine correct frequency and voltage pairings. We can
+ * do _PDC and _PSD and find out the processor dependency for the
+ * actual init that will happen later...
+ */
+static int acpi_cpufreq_early_init_acpi(void)
+{
+        struct acpi_processor_performance       *data;
+        unsigned int                            i, j;
+
+        dprintk("acpi_cpufreq_early_init\n");
+
+        for_each_cpu(i) {
+                data = kzalloc(sizeof(struct acpi_processor_performance), 
+                        GFP_KERNEL);
+                if (!data) {
+                        for_each_cpu(j) {
+                                kfree(acpi_perf_data[j]);
+                                acpi_perf_data[j] = NULL;
+                        }
+                        return (-ENOMEM);
+                }
+                acpi_perf_data[i] = data;
+        }
+
+        /* Do initialization in ACPI core */
+        acpi_processor_preregister_performance(acpi_perf_data);
+        return 0;
+}
+
 static int
 acpi_cpufreq_cpu_init (
         struct cpufreq_policy   *policy)
@@ -304,41 +395,51 @@ acpi_cpufreq_cpu_init (
         struct cpufreq_acpi_io  *data;
         unsigned int            result = 0;
         struct cpuinfo_x86 *c = &cpu_data[policy->cpu];
+        struct acpi_processor_performance       *perf;
 
         dprintk("acpi_cpufreq_cpu_init\n");
 
+        if (!acpi_perf_data[cpu])
+                return (-ENODEV);
+
         data = kzalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL);
         if (!data)
                 return (-ENOMEM);
 
+        data->acpi_data = acpi_perf_data[cpu];
         acpi_io_data[cpu] = data;
 
-        result = acpi_processor_register_performance(&data->acpi_data, cpu);
+        result = acpi_processor_register_performance(data->acpi_data, cpu);
 
         if (result)
                 goto err_free;
 
+        perf = data->acpi_data;
+        policy->cpus = perf->shared_cpu_map;
+        policy->shared_type = perf->shared_type;
+
         if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) {
                 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
         }
 
         /* capability check */
-        if (data->acpi_data.state_count <= 1) {
+        if (perf->state_count <= 1) {
                 dprintk("No P-States\n");
                 result = -ENODEV;
                 goto err_unreg;
         }
-        if ((data->acpi_data.control_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO) ||
-            (data->acpi_data.status_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO)) {
+
+        if ((perf->control_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO) ||
+            (perf->status_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO)) {
                 dprintk("Unsupported address space [%d, %d]\n",
-                        (u32) (data->acpi_data.control_register.space_id),
-                        (u32) (data->acpi_data.status_register.space_id));
+                        (u32) (perf->control_register.space_id),
+                        (u32) (perf->status_register.space_id));
                 result = -ENODEV;
                 goto err_unreg;
         }
 
         /* alloc freq_table */
-        data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) * (data->acpi_data.state_count + 1), GFP_KERNEL);
+        data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) * (perf->state_count + 1), GFP_KERNEL);
         if (!data->freq_table) {
                 result = -ENOMEM;
                 goto err_unreg;
@@ -346,9 +447,9 @@ acpi_cpufreq_cpu_init (
 
         /* detect transition latency */
         policy->cpuinfo.transition_latency = 0;
-        for (i=0; i<data->acpi_data.state_count; i++) {
-                if ((data->acpi_data.states[i].transition_latency * 1000) > policy->cpuinfo.transition_latency)
-                        policy->cpuinfo.transition_latency = data->acpi_data.states[i].transition_latency * 1000;
+        for (i=0; i<perf->state_count; i++) {
+                if ((perf->states[i].transition_latency * 1000) > policy->cpuinfo.transition_latency)
+                        policy->cpuinfo.transition_latency = perf->states[i].transition_latency * 1000;
         }
         policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
 
@@ -356,11 +457,11 @@ acpi_cpufreq_cpu_init (
         policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
 
         /* table init */
-        for (i=0; i<=data->acpi_data.state_count; i++)
+        for (i=0; i<=perf->state_count; i++)
         {
                 data->freq_table[i].index = i;
-                if (i<data->acpi_data.state_count)
-                        data->freq_table[i].frequency = data->acpi_data.states[i].core_frequency * 1000;
+                if (i<perf->state_count)
+                        data->freq_table[i].frequency = perf->states[i].core_frequency * 1000;
                 else
                         data->freq_table[i].frequency = CPUFREQ_TABLE_END;
         }
@@ -375,12 +476,12 @@ acpi_cpufreq_cpu_init (
 
         printk(KERN_INFO "acpi-cpufreq: CPU%u - ACPI performance management activated.\n",
                cpu);
-        for (i = 0; i < data->acpi_data.state_count; i++)
+        for (i = 0; i < perf->state_count; i++)
                 dprintk("     %cP%d: %d MHz, %d mW, %d uS\n",
-                        (i == data->acpi_data.state?'*':' '), i,
-                        (u32) data->acpi_data.states[i].core_frequency,
-                        (u32) data->acpi_data.states[i].power,
-                        (u32) data->acpi_data.states[i].transition_latency);
+                        (i == perf->state?'*':' '), i,
+                        (u32) perf->states[i].core_frequency,
+                        (u32) perf->states[i].power,
+                        (u32) perf->states[i].transition_latency);
 
         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
         
@@ -395,7 +496,7 @@ acpi_cpufreq_cpu_init (
  err_freqfree:
         kfree(data->freq_table);
  err_unreg:
-        acpi_processor_unregister_performance(&data->acpi_data, cpu);
+        acpi_processor_unregister_performance(perf, cpu);
  err_free:
         kfree(data);
         acpi_io_data[cpu] = NULL;
@@ -416,7 +517,7 @@ acpi_cpufreq_cpu_exit (
         if (data) {
                 cpufreq_frequency_table_put_attr(policy->cpu);
                 acpi_io_data[policy->cpu] = NULL;
-                acpi_processor_unregister_performance(&data->acpi_data, policy->cpu);
+                acpi_processor_unregister_performance(data->acpi_data, policy->cpu);
                 kfree(data);
         }
 
@@ -462,7 +563,10 @@ acpi_cpufreq_init (void)
 
         dprintk("acpi_cpufreq_init\n");
 
-        result = cpufreq_register_driver(&acpi_cpufreq_driver);
+        result = acpi_cpufreq_early_init_acpi();
+
+        if (!result)
+                result = cpufreq_register_driver(&acpi_cpufreq_driver);
         
         return (result);
 }
@@ -471,10 +575,15 @@ acpi_cpufreq_init (void)
 static void __exit
 acpi_cpufreq_exit (void)
 {
+        unsigned int    i;
         dprintk("acpi_cpufreq_exit\n");
 
         cpufreq_unregister_driver(&acpi_cpufreq_driver);
 
+        for_each_cpu(i) {
+                kfree(acpi_perf_data[i]);
+                acpi_perf_data[i] = NULL;
+        }
         return;
 }