[PATCH 2/3] ARM: gic: Use cpu pm notifiers to save gic state
From: Lorenzo Pieralisi <hidden>
Date: 2011-06-13 10:41:58
Also in:
lkml
Hi Colin, On Mon, Jun 13, 2011 at 01:43:44AM +0100, Colin Cross wrote:
When the cpu is powered down in a low power mode, the gic cpu interface may be reset, and when the cpu complex is powered down, the gic distributor may also be reset. This patch uses CPU_PM_ENTER and CPU_PM_EXIT notifiers to save and restore the gic cpu interface registers, and the CPU_COMPLEX_PM_ENTER and CPU_COMPLEX_PM_EXIT notifiers to save and restore the gic distributor registers. Signed-off-by: Colin Cross <redacted> --- arch/arm/common/gic.c | 212 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 212 insertions(+), 0 deletions(-)
[...]
quoted hunk ↗ jump to hunk
+ +static void __init gic_cpu_pm_init(struct gic_chip_data *gic) +{ + gic->saved_ppi_enable = __alloc_percpu(DIV_ROUND_UP(32, 32) * 4, + sizeof(u32)); + BUG_ON(!gic->saved_ppi_enable); + + gic->saved_ppi_conf = __alloc_percpu(DIV_ROUND_UP(32, 16) * 4, + sizeof(u32)); + BUG_ON(!gic->saved_ppi_conf); + + gic->saved_ppi_pri = __alloc_percpu(DIV_ROUND_UP(32, 4) * 4, + sizeof(u32)); + BUG_ON(!gic->saved_ppi_pri); + + cpu_pm_register_notifier(&gic_notifier_block); +} +#else +static void __init gic_cpu_pm_init(struct gic_chip_data *gic) +{ +} +#endif + void __init gic_init(unsigned int gic_nr, unsigned int irq_start, void __iomem *dist_base, void __iomem *cpu_base) {@@ -367,6 +578,7 @@ void __init gic_init(unsigned int gic_nr, unsigned int irq_start, gic_dist_init(gic, irq_start); gic_cpu_init(gic); + gic_cpu_pm_init(gic); }
I have been using this patchset for a while and it works perfectly fine. I reckon one bit we could improve is allowing to register a subsystem depending on a flag set @init, for now it is a save "all default registered subsystems or nothing" solution on cpu_pm_enter(), maybe we could add this level of configurability as an improvement (GIC being a good example, see OMAP). Lorenzo