linux/arch/powerpc/platforms/powernv/powernv.h

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#ifndef _POWERNV_H
#define _POWERNV_H
#ifdef CONFIG_SMP
extern void pnv_smp_init(void);
#else
static inline void pnv_smp_init(void) { }
#endif
struct pci_dev;
#ifdef CONFIG_PCI
extern void pnv_pci_init(void);
extern void pnv_pci_shutdown(void);
#else
static inline void pnv_pci_init(void) { }
static inline void pnv_pci_shutdown(void) { }
#endif
extern u32 pnv_get_supported_cpuidle_states(void);
extern void pnv_lpc_init(void);
extern void opal_handle_events(uint64_t events);
extern void opal_event_shutdown(void);
powerpc/powernv: Add support for POWER8 split core on powernv Upcoming POWER8 chips support a concept called split core. This is where the core can be split into subcores that although not full cores, are able to appear as full cores to a guest. The splitting & unsplitting procedure is mildly complicated, and explained at length in the comments within the patch. One notable detail is that when splitting or unsplitting we need to pull offline cpus out of their offline state to do work as part of the procedure. The interface for changing the split mode is via a sysfs file, eg: $ echo 2 > /sys/devices/system/cpu/subcores_per_core Currently supported values are '1', '2' and '4'. And indicate respectively that the core should be unsplit, split in half, and split in quarters. These modes correspond to threads_per_subcore of 8, 4 and 2. We do not allow changing the split mode while KVM VMs are active. This is to prevent the value changing while userspace is configuring the VM, and also to prevent the mode being changed in such a way that existing guests are unable to be run. CPU hotplug fixes by Srivatsa. max_cpus fixes by Mahesh. cpuset fixes by benh. Fix for irq race by paulus. The rest by mikey and mpe. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-05-23 08:15:30 +00:00
bool cpu_core_split_required(void);
#endif /* _POWERNV_H */