]> Pileus Git - ~andy/linux/blobdiff - drivers/acpi/processor_idle.c
ACPI: restore comment justifying 'extra' P_LVLx access
[~andy/linux] / drivers / acpi / processor_idle.c
index eb730a80952c6bc58c0cf3b0be80b9daf4aaf993..5551bfbc47aa565daccc5df43e42af5ee80c9c21 100644 (file)
@@ -54,10 +54,10 @@ ACPI_MODULE_NAME("acpi_processor")
 #define US_TO_PM_TIMER_TICKS(t)                ((t * (PM_TIMER_FREQUENCY/1000)) / 1000)
 #define C2_OVERHEAD                    4       /* 1us (3.579 ticks per us) */
 #define C3_OVERHEAD                    4       /* 1us (3.579 ticks per us) */
-static void (*pm_idle_save) (void);
+static void (*pm_idle_save) (void) __read_mostly;
 module_param(max_cstate, uint, 0644);
 
-static unsigned int nocst = 0;
+static unsigned int nocst __read_mostly;
 module_param(nocst, uint, 0000);
 
 /*
@@ -67,7 +67,7 @@ module_param(nocst, uint, 0000);
  * 100 HZ: 0x0000000F: 4 jiffies = 40ms
  * reduce history for more aggressive entry into C3
  */
-static unsigned int bm_history =
+static unsigned int bm_history __read_mostly =
     (HZ >= 800 ? 0xFFFFFFFF : ((1U << (HZ / 25)) - 1));
 module_param(bm_history, uint, 0644);
 /* --------------------------------------------------------------------------
@@ -206,11 +206,11 @@ acpi_processor_power_activate(struct acpi_processor *pr,
 
 static void acpi_safe_halt(void)
 {
-       clear_thread_flag(TIF_POLLING_NRFLAG);
+       current_thread_info()->status &= ~TS_POLLING;
        smp_mb__after_clear_bit();
        if (!need_resched())
                safe_halt();
-       set_thread_flag(TIF_POLLING_NRFLAG);
+       current_thread_info()->status |= TS_POLLING;
 }
 
 static atomic_t c3_cpu_count;
@@ -330,10 +330,10 @@ static void acpi_processor_idle(void)
         * Invoke the current Cx state to put the processor to sleep.
         */
        if (cx->type == ACPI_STATE_C2 || cx->type == ACPI_STATE_C3) {
-               clear_thread_flag(TIF_POLLING_NRFLAG);
+               current_thread_info()->status &= ~TS_POLLING;
                smp_mb__after_clear_bit();
                if (need_resched()) {
-                       set_thread_flag(TIF_POLLING_NRFLAG);
+                       current_thread_info()->status |= TS_POLLING;
                        local_irq_enable();
                        return;
                }
@@ -365,13 +365,20 @@ static void acpi_processor_idle(void)
                t1 = inl(acpi_fadt.xpm_tmr_blk.address);
                /* Invoke C2 */
                inb(cx->address);
-               /* Dummy op - must do something useless after P_LVL2 read */
+               /* Dummy wait op - must do something useless after P_LVL2 read
+                  because chipsets cannot guarantee that STPCLK# signal
+                  gets asserted in time to freeze execution properly. */
                t2 = inl(acpi_fadt.xpm_tmr_blk.address);
                /* Get end time (ticks) */
                t2 = inl(acpi_fadt.xpm_tmr_blk.address);
+
+#ifdef CONFIG_GENERIC_TIME
+               /* TSC halts in C2, so notify users */
+               mark_tsc_unstable();
+#endif
                /* Re-enable interrupts */
                local_irq_enable();
-               set_thread_flag(TIF_POLLING_NRFLAG);
+               current_thread_info()->status |= TS_POLLING;
                /* Compute time (ticks) that we were actually asleep */
                sleep_ticks =
                    ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD;
@@ -398,7 +405,7 @@ static void acpi_processor_idle(void)
                t1 = inl(acpi_fadt.xpm_tmr_blk.address);
                /* Invoke C3 */
                inb(cx->address);
-               /* Dummy op - must do something useless after P_LVL3 read */
+               /* Dummy wait op (see above) */
                t2 = inl(acpi_fadt.xpm_tmr_blk.address);
                /* Get end time (ticks) */
                t2 = inl(acpi_fadt.xpm_tmr_blk.address);
@@ -409,9 +416,13 @@ static void acpi_processor_idle(void)
                                          ACPI_MTX_DO_NOT_LOCK);
                }
 
+#ifdef CONFIG_GENERIC_TIME
+               /* TSC halts in C3, so notify users */
+               mark_tsc_unstable();
+#endif
                /* Re-enable interrupts */
                local_irq_enable();
-               set_thread_flag(TIF_POLLING_NRFLAG);
+               current_thread_info()->status |= TS_POLLING;
                /* Compute time (ticks) that we were actually asleep */
                sleep_ticks =
                    ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD;
@@ -508,10 +519,9 @@ static int acpi_processor_set_power_policy(struct acpi_processor *pr)
        struct acpi_processor_cx *higher = NULL;
        struct acpi_processor_cx *cx;
 
-       ACPI_FUNCTION_TRACE("acpi_processor_set_power_policy");
 
        if (!pr)
-               return_VALUE(-EINVAL);
+               return -EINVAL;
 
        /*
         * This function sets the default Cx state policy (OS idle handler).
@@ -535,7 +545,7 @@ static int acpi_processor_set_power_policy(struct acpi_processor *pr)
        }
 
        if (!state_is_set)
-               return_VALUE(-ENODEV);
+               return -ENODEV;
 
        /* demotion */
        for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
@@ -574,18 +584,17 @@ static int acpi_processor_set_power_policy(struct acpi_processor *pr)
                higher = cx;
        }
 
-       return_VALUE(0);
+       return 0;
 }
 
 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 {
-       ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_fadt");
 
        if (!pr)
-               return_VALUE(-EINVAL);
+               return -EINVAL;
 
        if (!pr->pblk)
-               return_VALUE(-ENODEV);
+               return -ENODEV;
 
        /* if info is obtained from pblk/fadt, type equals state */
        pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
@@ -597,7 +606,7 @@ static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
         * an SMP system. 
         */
        if ((num_online_cpus() > 1) && !acpi_fadt.plvl2_up)
-               return_VALUE(-ENODEV);
+               return -ENODEV;
 #endif
 
        /* determine C2 and C3 address from pblk */
@@ -613,12 +622,11 @@ static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
                          pr->power.states[ACPI_STATE_C2].address,
                          pr->power.states[ACPI_STATE_C3].address));
 
-       return_VALUE(0);
+       return 0;
 }
 
 static int acpi_processor_get_power_info_default_c1(struct acpi_processor *pr)
 {
-       ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_default_c1");
 
        /* Zero initialize all the C-states info. */
        memset(pr->power.states, 0, sizeof(pr->power.states));
@@ -631,7 +639,7 @@ static int acpi_processor_get_power_info_default_c1(struct acpi_processor *pr)
        pr->power.states[ACPI_STATE_C0].valid = 1;
        pr->power.states[ACPI_STATE_C1].valid = 1;
 
-       return_VALUE(0);
+       return 0;
 }
 
 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
@@ -643,10 +651,9 @@ static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
        union acpi_object *cst;
 
-       ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_cst");
 
        if (nocst)
-               return_VALUE(-ENODEV);
+               return -ENODEV;
 
        current_count = 1;
 
@@ -658,15 +665,14 @@ static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
        status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
        if (ACPI_FAILURE(status)) {
                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
-               return_VALUE(-ENODEV);
+               return -ENODEV;
        }
 
        cst = (union acpi_object *)buffer.pointer;
 
        /* There must be at least 2 elements */
        if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
-               ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
-                                 "not enough elements in _CST\n"));
+               printk(KERN_ERR PREFIX "not enough elements in _CST\n");
                status = -EFAULT;
                goto end;
        }
@@ -675,8 +681,7 @@ static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 
        /* Validate number of power states. */
        if (count < 1 || count != cst->package.count - 1) {
-               ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
-                                 "count given by _CST is not valid\n"));
+               printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
                status = -EFAULT;
                goto end;
        }
@@ -766,15 +771,14 @@ static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
       end:
        acpi_os_free(buffer.pointer);
 
-       return_VALUE(status);
+       return status;
 }
 
 static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
 {
-       ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c2");
 
        if (!cx->address)
-               return_VOID;
+               return;
 
        /*
         * C2 latency must be less than or equal to 100
@@ -783,7 +787,7 @@ static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
        else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                                  "latency too large [%d]\n", cx->latency));
-               return_VOID;
+               return;
        }
 
        /*
@@ -793,7 +797,7 @@ static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
        cx->valid = 1;
        cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
 
-       return_VOID;
+       return;
 }
 
 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
@@ -801,10 +805,9 @@ static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 {
        static int bm_check_flag;
 
-       ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c3");
 
        if (!cx->address)
-               return_VOID;
+               return;
 
        /*
         * C3 latency must be less than or equal to 1000
@@ -813,7 +816,7 @@ static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
        else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                                  "latency too large [%d]\n", cx->latency));
-               return_VOID;
+               return;
        }
 
        /*
@@ -826,7 +829,7 @@ static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
        else if (errata.piix4.fdma) {
                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                                  "C3 not supported on PIIX4 with Type-F DMA\n"));
-               return_VOID;
+               return;
        }
 
        /* All the logic here assumes flags.bm_check is same across all CPUs */
@@ -843,7 +846,7 @@ static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
                if (!pr->flags.bm_control) {
                        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                                          "C3 support requires bus mastering control\n"));
-                       return_VOID;
+                       return;
                }
        } else {
                /*
@@ -854,7 +857,7 @@ static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
                        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                                          "Cache invalidation should work properly"
                                          " for C3 to be enabled on SMP systems\n"));
-                       return_VOID;
+                       return;
                }
                acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD,
                                  0, ACPI_MTX_DO_NOT_LOCK);
@@ -869,7 +872,7 @@ static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
        cx->valid = 1;
        cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
 
-       return_VOID;
+       return;
 }
 
 static int acpi_processor_power_verify(struct acpi_processor *pr)
@@ -878,12 +881,9 @@ static int acpi_processor_power_verify(struct acpi_processor *pr)
        unsigned int working = 0;
 
 #ifdef ARCH_APICTIMER_STOPS_ON_C3
-       struct cpuinfo_x86 *c = cpu_data + pr->id;
+       int timer_broadcast = 0;
        cpumask_t mask = cpumask_of_cpu(pr->id);
-
-       if (c->x86_vendor == X86_VENDOR_INTEL) {
-               on_each_cpu(switch_ipi_to_APIC_timer, &mask, 1, 1);
-       }
+       on_each_cpu(switch_ipi_to_APIC_timer, &mask, 1, 1);
 #endif
 
        for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
@@ -896,15 +896,20 @@ static int acpi_processor_power_verify(struct acpi_processor *pr)
 
                case ACPI_STATE_C2:
                        acpi_processor_power_verify_c2(cx);
+#ifdef ARCH_APICTIMER_STOPS_ON_C3
+                       /* Some AMD systems fake C3 as C2, but still
+                          have timer troubles */
+                       if (cx->valid && 
+                               boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
+                               timer_broadcast++;
+#endif
                        break;
 
                case ACPI_STATE_C3:
                        acpi_processor_power_verify_c3(pr, cx);
 #ifdef ARCH_APICTIMER_STOPS_ON_C3
-                       if (cx->valid && c->x86_vendor == X86_VENDOR_INTEL) {
-                               on_each_cpu(switch_APIC_timer_to_ipi,
-                                               &mask, 1, 1);
-                       }
+                       if (cx->valid)
+                               timer_broadcast++;
 #endif
                        break;
                }
@@ -913,6 +918,11 @@ static int acpi_processor_power_verify(struct acpi_processor *pr)
                        working++;
        }
 
+#ifdef ARCH_APICTIMER_STOPS_ON_C3
+       if (timer_broadcast)
+               on_each_cpu(switch_APIC_timer_to_ipi, &mask, 1, 1);
+#endif
+
        return (working);
 }
 
@@ -921,7 +931,6 @@ static int acpi_processor_get_power_info(struct acpi_processor *pr)
        unsigned int i;
        int result;
 
-       ACPI_FUNCTION_TRACE("acpi_processor_get_power_info");
 
        /* NOTE: the idle thread may not be running while calling
         * this function */
@@ -944,7 +953,7 @@ static int acpi_processor_get_power_info(struct acpi_processor *pr)
         */
        result = acpi_processor_set_power_policy(pr);
        if (result)
-               return_VALUE(result);
+               return result;
 
        /*
         * if one state of type C2 or C3 is available, mark this
@@ -958,24 +967,23 @@ static int acpi_processor_get_power_info(struct acpi_processor *pr)
                }
        }
 
-       return_VALUE(0);
+       return 0;
 }
 
 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
 {
        int result = 0;
 
-       ACPI_FUNCTION_TRACE("acpi_processor_cst_has_changed");
 
        if (!pr)
-               return_VALUE(-EINVAL);
+               return -EINVAL;
 
        if (nocst) {
-               return_VALUE(-ENODEV);
+               return -ENODEV;
        }
 
        if (!pr->flags.power_setup_done)
-               return_VALUE(-ENODEV);
+               return -ENODEV;
 
        /* Fall back to the default idle loop */
        pm_idle = pm_idle_save;
@@ -986,7 +994,7 @@ int acpi_processor_cst_has_changed(struct acpi_processor *pr)
        if ((pr->flags.power == 1) && (pr->flags.power_setup_done))
                pm_idle = acpi_processor_idle;
 
-       return_VALUE(result);
+       return result;
 }
 
 /* proc interface */
@@ -996,7 +1004,6 @@ static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
        struct acpi_processor *pr = (struct acpi_processor *)seq->private;
        unsigned int i;
 
-       ACPI_FUNCTION_TRACE("acpi_processor_power_seq_show");
 
        if (!pr)
                goto end;
@@ -1054,7 +1061,7 @@ static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
        }
 
       end:
-       return_VALUE(0);
+       return 0;
 }
 
 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
@@ -1074,11 +1081,10 @@ int acpi_processor_power_init(struct acpi_processor *pr,
                              struct acpi_device *device)
 {
        acpi_status status = 0;
-       static int first_run = 0;
+       static int first_run;
        struct proc_dir_entry *entry = NULL;
        unsigned int i;
 
-       ACPI_FUNCTION_TRACE("acpi_processor_power_init");
 
        if (!first_run) {
                dmi_check_system(processor_power_dmi_table);
@@ -1090,14 +1096,14 @@ int acpi_processor_power_init(struct acpi_processor *pr,
        }
 
        if (!pr)
-               return_VALUE(-EINVAL);
+               return -EINVAL;
 
        if (acpi_fadt.cst_cnt && !nocst) {
                status =
                    acpi_os_write_port(acpi_fadt.smi_cmd, acpi_fadt.cst_cnt, 8);
                if (ACPI_FAILURE(status)) {
-                       ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
-                                         "Notifying BIOS of _CST ability failed\n"));
+                       ACPI_EXCEPTION((AE_INFO, status,
+                                       "Notifying BIOS of _CST ability failed"));
                }
        }
 
@@ -1126,9 +1132,7 @@ int acpi_processor_power_init(struct acpi_processor *pr,
        entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER,
                                  S_IRUGO, acpi_device_dir(device));
        if (!entry)
-               ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
-                                 "Unable to create '%s' fs entry\n",
-                                 ACPI_PROCESSOR_FILE_POWER));
+               return -EIO;
        else {
                entry->proc_fops = &acpi_processor_power_fops;
                entry->data = acpi_driver_data(device);
@@ -1137,13 +1141,12 @@ int acpi_processor_power_init(struct acpi_processor *pr,
 
        pr->flags.power_setup_done = 1;
 
-       return_VALUE(0);
+       return 0;
 }
 
 int acpi_processor_power_exit(struct acpi_processor *pr,
                              struct acpi_device *device)
 {
-       ACPI_FUNCTION_TRACE("acpi_processor_power_exit");
 
        pr->flags.power_setup_done = 0;
 
@@ -1163,5 +1166,5 @@ int acpi_processor_power_exit(struct acpi_processor *pr,
                cpu_idle_wait();
        }
 
-       return_VALUE(0);
+       return 0;
 }