From 46bcfad7a819bd17ac4e831b04405152d59784ab Mon Sep 17 00:00:00 2001 From: Deepthi Dharwar Date: Fri, 28 Oct 2011 16:20:42 +0530 Subject: cpuidle: Single/Global registration of idle states This patch makes the cpuidle_states structure global (single copy) instead of per-cpu. The statistics needed on per-cpu basis by the governor are kept per-cpu. This simplifies the cpuidle subsystem as state registration is done by single cpu only. Having single copy of cpuidle_states saves memory. Rare case of asymmetric C-states can be handled within the cpuidle driver and architectures such as POWER do not have asymmetric C-states. Having single/global registration of all the idle states, dynamic C-state transitions on x86 are handled by the boot cpu. Here, the boot cpu would disable all the devices, re-populate the states and later enable all the devices, irrespective of the cpu that would receive the notification first. Reference: https://lkml.org/lkml/2011/4/25/83 Signed-off-by: Deepthi Dharwar Signed-off-by: Trinabh Gupta Tested-by: Jean Pihet Reviewed-by: Kevin Hilman Acked-by: Arjan van de Ven Acked-by: Kevin Hilman Signed-off-by: Len Brown --- arch/arm/mach-davinci/cpuidle.c | 39 +++++++++++++++++++++------------------ 1 file changed, 21 insertions(+), 18 deletions(-) (limited to 'arch/arm/mach-davinci') diff --git a/arch/arm/mach-davinci/cpuidle.c b/arch/arm/mach-davinci/cpuidle.c index f2d2f34603d9..dbeeccd00173 100644 --- a/arch/arm/mach-davinci/cpuidle.c +++ b/arch/arm/mach-davinci/cpuidle.c @@ -78,6 +78,7 @@ static struct davinci_ops davinci_states[DAVINCI_CPUIDLE_MAX_STATES] = { /* Actual code that puts the SoC in different idle states */ static int davinci_enter_idle(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) { struct cpuidle_state_usage *state_usage = &dev->states_usage[index]; @@ -109,6 +110,7 @@ static int __init davinci_cpuidle_probe(struct platform_device *pdev) { int ret; struct cpuidle_device *device; + struct cpuidle_driver *driver = &davinci_idle_driver; struct davinci_cpuidle_config *pdata = pdev->dev.platform_data; device = &per_cpu(davinci_cpuidle_device, smp_processor_id()); @@ -120,32 +122,33 @@ static int __init davinci_cpuidle_probe(struct platform_device *pdev) ddr2_reg_base = pdata->ddr2_ctlr_base; - ret = cpuidle_register_driver(&davinci_idle_driver); - if (ret) { - dev_err(&pdev->dev, "failed to register driver\n"); - return ret; - } - /* Wait for interrupt state */ - device->states[0].enter = davinci_enter_idle; - device->states[0].exit_latency = 1; - device->states[0].target_residency = 10000; - device->states[0].flags = CPUIDLE_FLAG_TIME_VALID; - strcpy(device->states[0].name, "WFI"); - strcpy(device->states[0].desc, "Wait for interrupt"); + driver->states[0].enter = davinci_enter_idle; + driver->states[0].exit_latency = 1; + driver->states[0].target_residency = 10000; + driver->states[0].flags = CPUIDLE_FLAG_TIME_VALID; + strcpy(driver->states[0].name, "WFI"); + strcpy(driver->states[0].desc, "Wait for interrupt"); /* Wait for interrupt and DDR self refresh state */ - device->states[1].enter = davinci_enter_idle; - device->states[1].exit_latency = 10; - device->states[1].target_residency = 10000; - device->states[1].flags = CPUIDLE_FLAG_TIME_VALID; - strcpy(device->states[1].name, "DDR SR"); - strcpy(device->states[1].desc, "WFI and DDR Self Refresh"); + driver->states[1].enter = davinci_enter_idle; + driver->states[1].exit_latency = 10; + driver->states[1].target_residency = 10000; + driver->states[1].flags = CPUIDLE_FLAG_TIME_VALID; + strcpy(driver->states[1].name, "DDR SR"); + strcpy(driver->states[1].desc, "WFI and DDR Self Refresh"); if (pdata->ddr2_pdown) davinci_states[1].flags |= DAVINCI_CPUIDLE_FLAGS_DDR2_PWDN; cpuidle_set_statedata(&device->states_usage[1], &davinci_states[1]); device->state_count = DAVINCI_CPUIDLE_MAX_STATES; + driver->state_count = DAVINCI_CPUIDLE_MAX_STATES; + + ret = cpuidle_register_driver(&davinci_idle_driver); + if (ret) { + dev_err(&pdev->dev, "failed to register driver\n"); + return ret; + } ret = cpuidle_register_device(device); if (ret) { -- cgit v1.2.3