kernel/arch/powerpc/sysdev/xics/icp-native.c, branch linux-4.16.y

powerpc: Use pr_warn instead of pr_warning

2017-12-04T00:54:34Z

At some point, pr_warning will be removed so all logging messages use a consistent _warn style. Update arch/powerpc/ Miscellanea: o Coalesce formats o Realign arguments o Use %s, __func__ instead of embedded function names o Remove unnecessary line continuations Signed-off-by: Joe Perches Acked-by: Geoff Levand [mpe: Rebase due to some %pOF changes.] Signed-off-by: Michael Ellerman

powerpc: Change the doorbell IPI calling convention

2017-04-13T13:34:33Z

Change the doorbell callers to know about their msgsnd addressing, rather than have them set a per-cpu target data tag at boot that gets sent to the cause_ipi functions. The data is only used for doorbell IPI functions, no other IPI types, so it makes sense to keep that detail local to doorbell. Have the platform code understand doorbell IPIs, rather than the interrupt controller code understand them. Platform code can look at capabilities it has available and decide which to use. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman

powerpc: Consolidate variants of real-mode MMIOs

2017-04-10T11:43:16Z

We have all sort of variants of MMIO accessors for the real mode instructions. This creates a clean set of accessors based on Linux normal naming conventions, replacing all occurrences of the old ones in the tree. I have purposefully removed the "out/in" variants in favor of only including __raw variants. Any code using these is already pretty much hand tuned to operate in a very specific environment. I've fixed up the 2 users (only one of them actually needed a barrier in the first place). Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Michael Ellerman

powerpc: Remove all usages of NO_IRQ

2016-09-20T10:57:12Z

NO_IRQ has been == 0 on powerpc for just over ten years (since commit 0ebfff1491ef ("[POWERPC] Add new interrupt mapping core and change platforms to use it")). It's also 0 on most other arches. Although it's fairly harmless, every now and then it causes confusion when a driver is built on powerpc and another arch which doesn't define NO_IRQ. There's at least 6 definitions of NO_IRQ in drivers/, at least some of which are to work around that problem. So we'd like to remove it. This is fairly trivial in the arch code, we just convert: if (irq == NO_IRQ) to if (!irq) if (irq != NO_IRQ) to if (irq) irq = NO_IRQ; to irq = 0; return NO_IRQ; to return 0; And a few other odd cases as well. At least for now we keep the #define NO_IRQ, because there is driver code that uses NO_IRQ and the fixes to remove those will go via other trees. Note we also change some occurrences in PPC sound drivers, drivers/ps3, and drivers/macintosh. Signed-off-by: Michael Ellerman

powerpc/xics: Add icp_native_cause_ipi_rm

2016-02-29T05:25:06Z

Function to cause an IPI by directly updating the MFFR register in the XICS. The function is meant for real-mode callers since they cannot use the smp_ops->cause_ipi function which uses an ioremapped address. Normal usage is for the the KVM real mode code to set the IPI message using smp_muxed_ipi_message_pass and then invoke icp_native_cause_ipi_rm to cause the actual IPI. The function requires kvm_hstate.xics_phys to have been initialized with the physical address of XICS. Signed-off-by: Suresh Warrier Acked-by: Michael Ellerman Signed-off-by: Paul Mackerras

powerpc: Make doorbell check preemption safe

2015-06-16T22:01:03Z

Doorbell can be used to cause ipi on cpus which are sibling threads on the same core. So icp_native_cause_ipi checks if the destination cpu is a sibling thread of the current cpu and uses doorbell in such cases. But while running with CONFIG_PREEMPT=y, since this section is preemtible, we can run into issues if after we check if the destination cpu is a sibling cpu, the task gets migrated from a sibling cpu to a cpu on another core. Fix this by using get_cpu()/ put_cpu() Signed-off-by: Shreyas B. Prabhu Signed-off-by: Michael Neuling Signed-off-by: Michael Ellerman

powerpc/powernv: Don't call generic code on offline cpus

2014-09-25T13:14:50Z

On PowerNV platforms, when a CPU is offline, we put it into nap mode. It's possible that the CPU wakes up from nap mode while it is still offline due to a stray IPI. A misdirected device interrupt could also potentially cause it to wake up. In that circumstance, we need to clear the interrupt so that the CPU can go back to nap mode. In the past the clearing of the interrupt was accomplished by briefly enabling interrupts and allowing the normal interrupt handling code (do_IRQ() etc.) to handle the interrupt. This has the problem that this code calls irq_enter() and irq_exit(), which call functions such as account_system_vtime() which use RCU internally. Use of RCU is not permitted on offline CPUs and will trigger errors if RCU checking is enabled. To avoid calling into any generic code which might use RCU, we adopt a different method of clearing interrupts on offline CPUs. Since we are on the PowerNV platform, we know that the system interrupt controller is a XICS being driven directly (i.e. not via hcalls) by the kernel. Hence this adds a new icp_native_flush_interrupt() function to the native-mode XICS driver and arranges to call that when an offline CPU is woken from nap. This new function reads the interrupt from the XICS. If it is an IPI, it clears the IPI; if it is a device interrupt, it prints a warning and disables the source. Then it does the end-of-interrupt processing for the interrupt. The other thing that briefly enabling interrupts did was to check and clear the irq_happened flag in this CPU's PACA. Therefore, after flushing the interrupt from the XICS, we also clear all bits except the PACA_IRQ_HARD_DIS (interrupts are hard disabled) bit from the irq_happened flag. The PACA_IRQ_HARD_DIS flag is set by power7_nap() and is left set to indicate that interrupts are hard disabled. This means we then have to ignore that flag in power7_nap(), which is reasonable since it doesn't indicate that any interrupt event needs servicing. Signed-off-by: Paul Mackerras Signed-off-by: Michael Ellerman

powerpc/powernv: Enable POWER8 doorbell IPIs

2014-06-11T07:05:12Z

This patch enables POWER8 doorbell IPIs on powernv. Since doorbells can only IPI within a core, we test to see when we can use doorbells and if not we fall back to XICS. This also enables hypervisor doorbells to wakeup us up from nap/sleep via the LPCR PECEDH bit. Based on tests by Anton, the best case IPI latency between two threads dropped from 894ns to 512ns. Signed-off-by: Michael Neuling Signed-off-by: Benjamin Herrenschmidt

powerpc: Add some endian annotations to time and xics code

2013-08-14T05:33:24Z

Fix a couple of sparse warnings. Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt

Merge tag 'kvm-3.10-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2013-05-05T21:47:31Z

Pull kvm updates from Gleb Natapov: "Highlights of the updates are: general: - new emulated device API - legacy device assignment is now optional - irqfd interface is more generic and can be shared between arches x86: - VMCS shadow support and other nested VMX improvements - APIC virtualization and Posted Interrupt hardware support - Optimize mmio spte zapping ppc: - BookE: in-kernel MPIC emulation with irqfd support - Book3S: in-kernel XICS emulation (incomplete) - Book3S: HV: migration fixes - BookE: more debug support preparation - BookE: e6500 support ARM: - reworking of Hyp idmaps s390: - ioeventfd for virtio-ccw And many other bug fixes, cleanups and improvements" * tag 'kvm-3.10-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (204 commits) kvm: Add compat_ioctl for device control API KVM: x86: Account for failing enable_irq_window for NMI window request KVM: PPC: Book3S: Add API for in-kernel XICS emulation kvm/ppc/mpic: fix missing unlock in set_base_addr() kvm/ppc: Hold srcu lock when calling kvm_io_bus_read/write kvm/ppc/mpic: remove users kvm/ppc/mpic: fix mmio region lists when multiple guests used kvm/ppc/mpic: remove default routes from documentation kvm: KVM_CAP_IOMMU only available with device assignment ARM: KVM: iterate over all CPUs for CPU compatibility check KVM: ARM: Fix spelling in error message ARM: KVM: define KVM_ARM_MAX_VCPUS unconditionally KVM: ARM: Fix API documentation for ONE_REG encoding ARM: KVM: promote vfp_host pointer to generic host cpu context ARM: KVM: add architecture specific hook for capabilities ARM: KVM: perform HYP initilization for hotplugged CPUs ARM: KVM: switch to a dual-step HYP init code ARM: KVM: rework HYP page table freeing ARM: KVM: enforce maximum size for identity mapped code ARM: KVM: move to a KVM provided HYP idmap ...