vserver 1.9.3

[linux-2.6.git] / arch / i386 / kernel / cpu / cpufreq / acpi.c

diff --git a/arch/i386/kernel/cpu/cpufreq/acpi.c b/arch/i386/kernel/cpu/cpufreq/acpi.c
index 8c05688..4ba9127 100644 (file)
--- a/arch/i386/kernel/cpu/cpufreq/acpi.c
+++ b/arch/i386/kernel/cpu/cpufreq/acpi.c
@@ -108,13 +108,27 @@ acpi_processor_set_performance (
        u32                     value = 0;
        int                     i = 0;
        struct cpufreq_freqs    cpufreq_freqs;
+       cpumask_t               saved_mask;
+       int                     retval;
 
        ACPI_FUNCTION_TRACE("acpi_processor_set_performance");
 
+       /*
+        * 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_VALUE(-EAGAIN);
+       }
+       
        if (state == data->acpi_data.state) {
                ACPI_DEBUG_PRINT((ACPI_DB_INFO, 
                        "Already at target state (P%d)\n", state));
-               return_VALUE(0);
+               retval = 0;
+               goto migrate_end;
        }
 
        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Transitioning from P%d to P%d\n",
@@ -144,7 +158,8 @@ acpi_processor_set_performance (
        if (ret) {
                ACPI_DEBUG_PRINT((ACPI_DB_WARN,
                        "Invalid port width 0x%04x\n", bit_width));
-               return_VALUE(ret);
+               retval = ret;
+               goto migrate_end;
        }
 
        /*
@@ -166,7 +181,8 @@ acpi_processor_set_performance (
                if (ret) {      
                        ACPI_DEBUG_PRINT((ACPI_DB_WARN,
                                "Invalid port width 0x%04x\n", bit_width));
-                       return_VALUE(ret);
+                       retval = ret;
+                       goto migrate_end;
                }
                if (value == (u32) data->acpi_data.states[state].status)
                        break;
@@ -183,7 +199,8 @@ acpi_processor_set_performance (
                cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);
                cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
                ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Transition failed\n"));
-               return_VALUE(-ENODEV);
+               retval = -ENODEV;
+               goto migrate_end;
        }
 
        ACPI_DEBUG_PRINT((ACPI_DB_INFO, 
@@ -192,7 +209,10 @@ acpi_processor_set_performance (
 
        data->acpi_data.state = state;
 
-       return_VALUE(0);
+       retval = 0;
+migrate_end:
+       set_cpus_allowed(current, saved_mask);
+       return_VALUE(retval);
 }
 
 
@@ -266,6 +286,69 @@ acpi_cpufreq_guess_freq (
        
 }
 
+
+/* 
+ * acpi_processor_cpu_init_pdc_est - let BIOS know about the SMP capabilities
+ * of this driver
+ * @perf: processor-specific acpi_io_data struct
+ * @cpu: CPU being initialized
+ *
+ * To avoid issues with legacy OSes, some BIOSes require to be informed of
+ * the SMP capabilities of OS P-state driver. Here we set the bits in _PDC 
+ * accordingly, for Enhanced Speedstep. Actual call to _PDC is done in
+ * driver/acpi/processor.c
+ */
+static void 
+acpi_processor_cpu_init_pdc_est(
+               struct acpi_processor_performance *perf, 
+               unsigned int cpu,
+               struct acpi_object_list *obj_list
+               )
+{
+       union acpi_object *obj;
+       u32 *buf;
+       struct cpuinfo_x86 *c = cpu_data + cpu;
+       ACPI_FUNCTION_TRACE("acpi_processor_cpu_init_pdc_est");
+
+       if (!cpu_has(c, X86_FEATURE_EST))
+               return_VOID;
+
+       /* Initialize pdc. It will be used later. */
+       if (!obj_list)
+               return_VOID;
+               
+       if (!(obj_list->count && obj_list->pointer))
+               return_VOID;
+
+       obj = obj_list->pointer;
+       if ((obj->buffer.length == 12) && obj->buffer.pointer) {
+               buf = (u32 *)obj->buffer.pointer;
+                       buf[0] = ACPI_PDC_REVISION_ID;
+                       buf[1] = 1;
+                       buf[2] = ACPI_PDC_EST_CAPABILITY_SMP;
+               perf->pdc = obj_list;
+       }
+       return_VOID;
+}
+ 
+
+/* CPU specific PDC initialization */
+static void 
+acpi_processor_cpu_init_pdc(
+               struct acpi_processor_performance *perf, 
+               unsigned int cpu,
+               struct acpi_object_list *obj_list
+               )
+{
+       struct cpuinfo_x86 *c = cpu_data + cpu;
+       ACPI_FUNCTION_TRACE("acpi_processor_cpu_init_pdc");
+       perf->pdc = NULL;
+       if (cpu_has(c, X86_FEATURE_EST))
+               acpi_processor_cpu_init_pdc_est(perf, cpu, obj_list);
+       return_VOID;
+}
+
+
 static int
 acpi_cpufreq_cpu_init (
        struct cpufreq_policy   *policy)
@@ -275,7 +358,14 @@ acpi_cpufreq_cpu_init (
        struct cpufreq_acpi_io  *data;
        unsigned int            result = 0;
 
+       union acpi_object               arg0 = {ACPI_TYPE_BUFFER};
+       u32                             arg0_buf[3];
+       struct acpi_object_list         arg_list = {1, &arg0};
+
        ACPI_FUNCTION_TRACE("acpi_cpufreq_cpu_init");
+       /* setup arg_list for _PDC settings */
+        arg0.buffer.length = 12;
+        arg0.buffer.pointer = (u8 *) arg0_buf;
 
        data = kmalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL);
        if (!data)
@@ -284,7 +374,10 @@ acpi_cpufreq_cpu_init (
 
        acpi_io_data[cpu] = data;
 
+       acpi_processor_cpu_init_pdc(&data->acpi_data, cpu, &arg_list);
        result = acpi_processor_register_performance(&data->acpi_data, cpu);
+       data->acpi_data.pdc = NULL;
+
        if (result)
                goto err_free;