1. 22 Nov, 2018 11 commits
    • Philippe Gerum's avatar
      arm64: ipipe: preserve the hard interrupt state across mayday trap · dec5e42f
      Philippe Gerum authored
      The mayday trap asks the co-kernel to deal with a runaway context
      which has been detected earlier. When doing so, the co-kernel might
      re-enable hard interrupts, which we have to disable again before
      unwinding the IRQ context which triggered the whole process (like a
      watchdog event).
      Use __ipipe_call_mayday() to fire the notification to the co-kernel
      instead of the open coded version, so that we do restore the hard
      interrupt state properly before leaving __ipipe_exit_irq().
    • Philippe Gerum's avatar
      arm64: ipipe: route all access traps to co-kernel · 41742503
      Philippe Gerum authored
      Notifying the co-kernel about major faults occurring in kernel context
      or user-space was overlooked. We need the co-kernel to restore the
      root stage whenever applicable before we may attempt to handle the
    • Philippe Gerum's avatar
    • Philippe Gerum's avatar
      arm64: dts: bcm2837: provide for BT-less variant, re-enabling uart0 as serial · d54e8259
      Philippe Gerum authored
      Raspberry 3 has two UARTs: uart0 is a full-fledged pl011 used for BT
      by default, uart1 is a poor-man's low throughput serial device dubbed
      as the "mini-uart". Unfortunately, uart1 is a massive pain, whose
      clock rate is based on the CPU clock rate: this makes it quite
      unstable as a serial console when a CPU frequency governor is enabled.
      When BT is useless, we'd rather switch uart0 from BT to the serial
      pins, disabling uart1 in the same move, so that we recover a decent
      console device (*) with a stable clocking.
      bcm2837-rpi-3-b-nobt.dtb is a fixed up blob doing exactly that.
      (*) cmdline should mention console=ttyAMA0,<speed>
    • Philippe Gerum's avatar
      arm64: ipipe: turn hard irqs on when leaving the idle state · b78aefb2
      Philippe Gerum authored
      As required to mimic the original behavior when interrupt pipelining
      is in effect.
    • Dmitriy Cherkasov's avatar
      arm64: fpsimd: ipipe: enable sharing with head domain · c09de98b
      Dmitriy Cherkasov authored
      Serialize accesses to the fpsimd so as to allow co-kernel activities
      (e.g. tasks) running in the head domain to share the unit with the
      host kernel.
    • Philippe Gerum's avatar
      arm64: ipipe: route syscalls to co-kernel · cf3a0a01
      Philippe Gerum authored
      This commit introduces the changes redirecting "foreign" system calls
      to the co-kernel.
    • Philippe Gerum's avatar
      arm64: ipipe: route traps to co-kernel · f5beda02
      Philippe Gerum authored
      This commit introduces the changes redirecting traps and exceptions to
      the interrupt pipeline, so that the co-kernel can be made aware early
      on. The co-kernel may then decide whether the fault should be
      propagated to the regular kernel for actual handling.
      This is typically useful for allowing the co-kernel to downgrade the
      current context from the head domain to the root domain, when leaving
      the burden of handling major faults to the regular kernel makes more
      sense than expecting the co-kernel to reinvent such a wheel
      (e.g. memory violations, illegal instructions, divide by zero etc). As
      a matter of fact, optimizing latency upon such events would not make
      much sense anyway.
    • Philippe Gerum's avatar
      arm64: ipipe: share context switch code with the head domain · 61203e83
      Philippe Gerum authored
      This change enable a co-kernel to change the address space of a task
      using the common mm helpers. This is mainly a matter of strictly
      serializing context switching code among all callers regardless of
      their domain (head/root), by disabling hard irqs.
    • Philippe Gerum's avatar
      arm64: context_tracking: disable if CONFIG_IPIPE · 63f55611
      Philippe Gerum authored
      Context tracking does not cope well with interrupt pipelining
      currently: disable the former for now.
    • Philippe Gerum's avatar
      arm64: ipipe: add pipeline core · 5d5e25dc
      Philippe Gerum authored
      Introduce the arm64-specific bits enabling the interrupt pipeline
  2. 01 Nov, 2018 29 commits
    • Philippe Gerum's avatar
      sched/core: ipipe: do not panic on failed migration to the head stage · 89ec8d23
      Philippe Gerum authored
      __ipipe_migrate_head() should not BUG() unconditionally when failing
      to schedule out a thread, but rather let the real-time core handle the
      situation a bit more gracefully.
    • Philippe Gerum's avatar
      ipipe: timer: prevent double-ack if host timer is not grabbed · a79165b1
      Philippe Gerum authored
      Only timers stolen away from the host kernel should be early acked by
      the pipeline core. Otherwise, the regular IRQ handler associated to
      the timer would duplicate the action. The IRQ line is left masked,
      waiting for the IRQ flow handler to unmask it eventually.
    • Philippe Gerum's avatar
      ipipe: timer: notify co-kernel about entering ONESHOT_STOPPED mode · 2259d365
      Philippe Gerum authored
      Although we don't want to disable the hardware not to wreck the
      outstanding timing requests managed by the co-kernel, we should
      nevertheless notify it about entering the ONESHOT_STOPPED mode, so
      that it may disable the host tick emulation.
    • Philippe Gerum's avatar
      ipipe: timer: do not interpose on undefined handlers · 80cf3074
      Philippe Gerum authored
      There is no point in interposing on clock chip handlers for which
      there was no support originally. In some cases (oneshot_stopped), we
      may even get a kernel fault, jumping to a NULL address.
      Interpose on non-NULL original handlers only.
    • Philippe Gerum's avatar
      ipipe: timer: resume hardware operations in oneshot handler · c23aae1e
      Philippe Gerum authored
      Although we won't allow disabling the hardware when the clock event
      logic switches a device to stopped mode - so that we won't affect the
      timer logic running on the head stage unexpectedly -, we still have to
      enable the hardware when switched (back) to oneshot mode, since it may
      have been stopped prior to interposing on the device in
      Failing to do so would leave the hardware shut down for both regular
      and Xenomai operations, with no mean to bring it up again.
    • Philippe Gerum's avatar
    • Philippe Gerum's avatar
    • Philippe Gerum's avatar
      sched: idle: ipipe: drop spurious check · a24a1f5b
      Philippe Gerum authored
    • Philippe Gerum's avatar
    • Philippe Gerum's avatar
      printk: ipipe: defer vprintk() output · 17183846
      Philippe Gerum authored
    • Philippe Gerum's avatar
      stop_machine: fix build in !SMP case · 74985847
      Philippe Gerum authored
    • Philippe Gerum's avatar
    • Philippe Gerum's avatar
      ipipe: tick: revive the host tick after device grab · fb24f93f
      Philippe Gerum authored
      Once the device was grabbed by ipipe_timer_start(), any pending host
      tick programmed in the hardware is basically lost, unknown to the
      co-kernel implementing the proxy handlers.
      Schedule a host event with the latest target time programmed to have
      the co-kernel know about the pending tick.
    • Philippe Gerum's avatar
      PM: ipipe: converge to Dovetail's CPUIDLE management · cb5702e0
      Philippe Gerum authored
      Handle requests for transitioning to deeper C-states the way Dovetail
      does, which prevents us from losing the timer when grabbed by a
      co-kernel, in presence of a CPUIDLE driver.
    • Philippe Gerum's avatar
      genirq: ipipe: add local_irq_{enable, disable}_full() helpers · c116c682
      Philippe Gerum authored
      Those helpers affect both the real (in CPU) and virtual interrupt
      states for the root stage, reconciling them.
    • Philippe Gerum's avatar
      ipipe: tick: cap timer_set op to device supported max · 78580ae1
      Philippe Gerum authored
      At this chance, switch the min_delay_tick value to unsigned long to
      match the corresponding clockevent definition.
    • Philippe Gerum's avatar
      ipipe: tick: out-of-band devices require GENERIC_CLOCKEVENTS · a1d64704
      Philippe Gerum authored
      Drop the legacy support for architectures not enabling the generic
      clock event framework, which would only provide periodic timing.
      We don't support any of those archs, and there is no point in running
      a Xenomai co-kernel on a hardware not capable of handling oneshot
      timing requests.
    • Philippe Gerum's avatar
      thermal/drivers/hisi: drop spurious enable of auto-enable irq · 82d07de0
      Philippe Gerum authored
      Fixes the kernel warning below due to the second enable sneaking in
      between a thermal IRQ is handled by the hard interrupt handler - which
      disables it - and the IRQ thread eventually attempts to re-enable the
      interrupt - which was already enabled.
      [    0.405830] Unbalanced enable for IRQ 44
      [    0.406029] ------------[ cut here ]------------
      [    0.406035] WARNING: CPU: 3 PID: 1285 at kernel/irq/manage.c:525 __enable_irq+0x60/0x70
      [    0.406044] Modules linked in:
      [    0.406055] CPU: 3 PID: 1285 Comm: irq/44-hisi_the Not tainted 4.14.62-ipipe #2
      [    0.406060] Hardware name: HiKey Development Board (DT)
      [    0.406065] I-pipe domain: Linux
      [    0.406073] task: ffff8000336b0000 task.stack: ffff00000b9e0000
      [    0.406078] PC is at __enable_irq+0x60/0x70
      [    0.406083] LR is at __enable_irq+0x60/0x70
      [    0.406088] pc : [<ffff000008124d58>] lr : [<ffff000008124d58>] pstate: 60000045
      [    0.406093] sp : ffff00000b9e3c60
      [    0.406098] x29: ffff00000b9e3c60 x28: 0000000000000000
      [    0.406108] x27: ffff00000805ba40 x26: ffff8000336b0000
      [    0.406118] x25: ffff000008124000 x24: ffff00000b9e3d7c
      [    0.406128] x23: 0000000000000002 x22: ffff800033f39e88
      [    0.406138] x21: 000000000000bc40 x20: 000000000000002c
      [    0.406147] x19: ffff800034275200 x18: 0000000000000010
      [    0.406157] x17: 0000000000000007 x16: 0000000000000001
      [    0.406166] x15: ffff0000890014c7 x14: 0000000000000006
      [    0.406175] x13: ffff0000090014d5 x12: ffff000008eb34d0
      [    0.406184] x11: ffff000008eb3000 x10: 0000000005f5e0ff
      [    0.406193] x9 : ffff00000b9e3970 x8 : 0000000000000040
      [    0.406202] x7 : ffff000008e7c000 x6 : 0000000000000040
      [    0.406211] x5 : 0000000000000000 x4 : 0000000000000000
      [    0.406220] x3 : ffffffffffffffff x2 : ffff000008eb34f0
      [    0.406229] x1 : ffff8000336b0000 x0 : 000000000000001c
      [    0.406239] Call trace:
      [    0.406244] Exception stack(0xffff00000b9e3b20 to 0xffff00000b9e3c60)
      [    0.406249] 3b20: 000000000000001c ffff8000336b0000 ffff000008eb34f0 ffffffffffffffff
      [    0.406255] 3b40: 0000000000000000 0000000000000000 0000000000000040 ffff000008e7c000
      [    0.406261] 3b60: 0000000000000040 ffff00000b9e3970 0000000005f5e0ff ffff000008eb3000
      [    0.406267] 3b80: ffff000008eb34d0 ffff0000090014d5 0000000000000006 ffff0000890014c7
      [    0.406272] 3ba0: 0000000000000001 0000000000000007 0000000000000010 ffff800034275200
      [    0.406278] 3bc0: 000000000000002c 000000000000bc40 ffff800033f39e88 0000000000000002
      [    0.406284] 3be0: ffff00000b9e3d7c ffff000008124000 ffff8000336b0000 ffff00000805ba40
      [    0.406289] 3c00: 0000000000000000 ffff00000b9e3c60 ffff000008124d58 ffff00000b9e3c60
      [    0.406295] 3c20: ffff000008124d58 0000000060000045 0000000000000000 ffff800034275200
      [    0.406300] 3c40: ffffffffffffffff ffff000008e7c2b0 ffff00000b9e3c60 ffff000008124d58
      [    0.406306] [<ffff000008124d58>] __enable_irq+0x60/0x70
      [    0.406311] [<ffff000008124d9c>] enable_irq+0x34/0x68
      [    0.406317] [<ffff000008780320>] hisi_thermal_get_temp+0x160/0x198
      [    0.406322] [<ffff00000877b868>] of_thermal_get_temp+0x20/0x30
      [    0.406327] [<ffff00000877b0d4>] thermal_zone_get_temp+0x5c/0x138
      [    0.406332] [<ffff000008778740>] thermal_zone_device_update.part.4+0x20/0xb0
      [    0.406337] [<ffff0000087787f8>] thermal_zone_device_update+0x28/0x38
      [    0.406342] [<ffff00000877fe7c>] hisi_thermal_alarm_irq_thread+0x64/0x80
      [    0.406347] [<ffff0000081244e0>] irq_thread_fn+0x28/0x68
      [    0.406352] [<ffff000008124784>] irq_thread+0x114/0x1b0
      [    0.406357] [<ffff0000080f0384>] kthread+0xfc/0x128
      [    0.406362] [<ffff000008085274>] ret_from_fork+0x14/0x20
      [    0.406366] ---[ end trace 0e6011135c69587a ]---
    • Philippe Gerum's avatar
    • Philippe Gerum's avatar
      ftrace: ipipe: rely on fully atomic stop_machine() handler · 92783263
      Philippe Gerum authored
      Now that stop_machine() guarantees fully atomic execution of the stop
      routine via hard interrupt disabling, there is no point in using
      ipipe_critical_enter/exit() for the same purpose in order to patch the
      kernel text.
    • Philippe Gerum's avatar
      stop_machine: ipipe: ensure atomic stop-context operations · aed125e2
      Philippe Gerum authored
      stop_machine() guarantees that all online CPUs are spinning
      non-preemptible in a known code location before a subset of them may
      safely run a stop-context function. This service is typically useful
      for live patching the kernel code, or changing global memory mappings,
      so that no activity could run in parallel until the system has
      returned to a stable state after all stop-context operations have
      When interrupt pipelining is enabled, we have to provide the same
      guarantee by restoring hard interrupt disabling where virtualizing the
      interrupt disable flag would defeat it.
    • Philippe Gerum's avatar
      lockdep: ipipe: improve detection of out-of-band contexts · 3e6b6433
      Philippe Gerum authored
      trace_hardirqs_on_virt[_caller]() must be invoked instead of
      trace_hardirqs_on[_caller]() from assembly sites before returning from
      an interrupt/fault, so that the virtual IRQ disable state is checked
      for before switching the tracer's logic state to ON.
      This is required as an interrupt may be received and handled by the
      pipeline core although not forwarded to the root domain, when
      interrupts are virtually disabled. In such a case, we want to
      reconcile the tracer's logic with the effect of interrupt pipelining.
    • Philippe Gerum's avatar
      lockdep: ipipe: make the logic aware of interrupt pipelining · 393ce342
      Philippe Gerum authored
      The lockdep engine will check for the current interrupt state as part
      of the locking validation process, which must encompass:
      - the CPU interrupt state
      - the current pipeline domain
      - the virtual interrupt disable flag
      so that we can traverse the tracepoints from any context sanely and
      In addition trace_hardirqs_on_virt_caller() should be called by the
      arch-dependent code when tracking the interrupt state before returning
      to user-space after a kernel entry (exceptions, IRQ). This makes sure
      that the tracking logic only applies to the root domain, and considers
      the virtual disable flag exclusively.
      For instance, the kernel may be entered when interrupts are (only)
      virtually disabled for the root domain (i.e. stalled), and we should
      tell the IRQ tracing logic that IRQs are about to be enabled back only
      if the root domain is unstalled before leaving to user-space. In such
      a context, the state of the interrupt bit in the CPU would be
    • Greg Gallagher's avatar
      drivers/dove: pmu: ipipe: fix build · 6704d0bd
      Greg Gallagher authored
    • Gilles Chanteperdrix's avatar
      drivers/dove: pmu: ipipe: enable interrupt pipelining · efdffb75
      Gilles Chanteperdrix authored
      Fix up the PMU controller driver of the Marvell Dove SoC in order to
      channel interrupts through the interrupt pipeline.
    • Philippe Gerum's avatar
      pci: dwc: ipipe: enable interrupt pipelining · 7f22e17b
      Philippe Gerum authored
      Fix up Synopsys's PCIE driver in order to channel interrupts through
      the interrupt pipeline.
    • Philippe Gerum's avatar
      pci: pcie-altera: ipipe: enable interrupt pipelining · 9f74838e
      Philippe Gerum authored
      Fix up Altera's PCIE driver in order to channel interrupts through the
      interrupt pipeline.
    • Philippe Gerum's avatar
      pinctrl: sunxi: ipipe: enable interrupt pipelining · f04d3165
      Philippe Gerum authored
      Fix up the pin controller driver of the Allwinner A1x SoCs in order to
      channel interrupts through the interrupt pipeline.
    • Philippe Gerum's avatar
      pinctrl: bcm2835: ipipe: enable interrupt pipelining · cff26083
      Philippe Gerum authored
      Fix up the pin controller driver of the Broadcom 2835 SoC in order to
      channel interrupts through the interrupt pipeline.