From 8eb8ac89a364305d05ad16be983b7890eb462cc3 Mon Sep 17 00:00:00 2001 From: "Shreyas B. Prabhu" Date: Wed, 10 Dec 2014 00:26:51 +0530 Subject: powerpc/powernv: Enable Offline CPUs to enter deep idle states The secondary threads should enter deep idle states so as to gain maximum powersavings when the entire core is offline. To do so the offline path must be made aware of the available deepest idle state. Hence probe the device tree for the possible idle states in powernv core code and expose the deepest idle state through flags. Since the device tree is probed by the cpuidle driver as well, move the parameters required to discover the idle states into an appropriate common place to both the driver and the powernv core code. Another point is that fastsleep idle state may require workarounds in the kernel to function properly. This workaround is introduced in the subsequent patches. However neither the cpuidle driver or the hotplug path need be bothered about this workaround. They will be taken care of by the core powernv code. Originally-by: Srivatsa S. Bhat Signed-off-by: Preeti U. Murthy Signed-off-by: Shreyas B. Prabhu Reviewed-by: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Rafael J. Wysocki Cc: linux-pm@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Michael Ellerman --- arch/powerpc/platforms/powernv/powernv.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/powerpc/platforms/powernv/powernv.h') diff --git a/arch/powerpc/platforms/powernv/powernv.h b/arch/powerpc/platforms/powernv/powernv.h index 6c8e2d188cd0..604c48e7879a 100644 --- a/arch/powerpc/platforms/powernv/powernv.h +++ b/arch/powerpc/platforms/powernv/powernv.h @@ -29,6 +29,8 @@ static inline u64 pnv_pci_dma_get_required_mask(struct pci_dev *pdev) } #endif +extern u32 pnv_get_supported_cpuidle_states(void); + extern void pnv_lpc_init(void); bool cpu_core_split_required(void); -- cgit v1.2.3