1. 06 Oct, 2017 4 commits
    • Seth Forshee's avatar
      powerpc: Always initialize input array when calling epapr_hypercall() · 186b8f15
      Seth Forshee authored
      Several callers to epapr_hypercall() pass an uninitialized stack
      allocated array for the input arguments, presumably because they
      have no input arguments. However this can produce errors like
      this one
      
       arch/powerpc/include/asm/epapr_hcalls.h:470:42: error: 'in' may be used uninitialized in this function [-Werror=maybe-uninitialized]
        unsigned long register r3 asm("r3") = in[0];
                                              ~~^~~
      
      Fix callers to this function to always zero-initialize the input
      arguments array to prevent this.
      Signed-off-by: default avatarSeth Forshee <seth.forshee@canonical.com>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      186b8f15
    • Michael Neuling's avatar
      powerpc: Add PPC_EMULATED_STATS to powernv_defconfig · e366b921
      Michael Neuling authored
      This is useful, especially for developers.
      Signed-off-by: default avatarMichael Neuling <mikey@neuling.org>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      e366b921
    • Guilherme G. Piccoli's avatar
      powerpc/xmon: Add option to show uptime information · 59d3391e
      Guilherme G. Piccoli authored
      It might be useful to quickly get the uptime of a running system on
      xmon, without needing to grab data from memory and doing math on
      struct addresses.
      
      For example, it'd be useful to check for how long after a crash a
      system is on xmon shell or if some test was started after the first
      test crashed (and this 2nd test crashed too into xmon).
      
      This small patch adds the 'U' command, to accomplish this.
      Suggested-by: default avatarMurilo Fossa Vicentini <muvic@linux.vnet.ibm.com>
      Signed-off-by: default avatarGuilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
      [mpe: Display units (seconds), add sync()/__delay() sequence]
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      59d3391e
    • Michael Ellerman's avatar
      powerpc/powernv: Make opal_event_shutdown() callable from IRQ context · c6baa077
      Michael Ellerman authored
      In opal_event_shutdown() we free all the IRQs hanging off the
      opal_event_irqchip. However it's not safe to do so if we're called
      from IRQ context, because free_irq() wants to synchronise versus IRQ
      context. This can lead to warnings and a stuck system.
      
      For example from sysrq-b:
      
        Trying to free IRQ 17 from IRQ context!
        ------------[ cut here ]------------
        WARNING: CPU: 0 PID: 0 at kernel/irq/manage.c:1461 __free_irq+0x398/0x8d0
        ...
        NIP __free_irq+0x398/0x8d0
        LR __free_irq+0x394/0x8d0
        Call Trace:
          __free_irq+0x394/0x8d0 (unreliable)
          free_irq+0xa4/0x140
          opal_event_shutdown+0x128/0x180
          opal_shutdown+0x1c/0xb0
          pnv_shutdown+0x20/0x40
          machine_restart+0x38/0x90
          emergency_restart+0x28/0x40
          sysrq_handle_reboot+0x24/0x40
          __handle_sysrq+0x198/0x590
          hvc_poll+0x48c/0x8c0
          hvc_handle_interrupt+0x1c/0x50
          __handle_irq_event_percpu+0xe8/0x6e0
          handle_irq_event_percpu+0x34/0xe0
          handle_irq_event+0xc4/0x210
          handle_level_irq+0x250/0x770
          generic_handle_irq+0x5c/0xa0
          opal_handle_events+0x11c/0x240
          opal_interrupt+0x38/0x50
          __handle_irq_event_percpu+0xe8/0x6e0
          handle_irq_event_percpu+0x34/0xe0
          handle_irq_event+0xc4/0x210
          handle_fasteoi_irq+0x174/0xa10
          generic_handle_irq+0x5c/0xa0
          __do_irq+0xbc/0x4e0
          call_do_irq+0x14/0x24
          do_IRQ+0x18c/0x540
          hardware_interrupt_common+0x158/0x180
      
      We can avoid that by using disable_irq_nosync() rather than
      free_irq(). Although it doesn't fully free the IRQ, it should be
      sufficient when we're shutting down, particularly in an emergency.
      
      Add an in_interrupt() check and use free_irq() when we're shutting
      down normally. It's probably OK to use disable_irq_nosync() in that
      case too, but for now it's safer to leave that behaviour as-is.
      
      Fixes: 9f0fd049 ("powerpc/powernv: Add a virtual irqchip for opal events")
      Reported-by: default avatarAnton Blanchard <anton@samba.org>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      c6baa077
  2. 05 Oct, 2017 2 commits
    • Naveen N. Rao's avatar
      powerpc/jprobes: Validate break handler invocation as being due to a jprobe_return() · 3368f569
      Naveen N. Rao authored
      Fix a circa 2005 FIXME by implementing a check to ensure that we
      actually got into the jprobe break handler() due to the trap in
      jprobe_return().
      Acked-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
      Signed-off-by: default avatarNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      3368f569
    • Naveen N. Rao's avatar
      powerpc/jprobes: Disable preemption when triggered through ftrace · 6baea433
      Naveen N. Rao authored
      KPROBES_SANITY_TEST throws the below splat when CONFIG_PREEMPT is
      enabled:
      
        Kprobe smoke test: started
        DEBUG_LOCKS_WARN_ON(val > preempt_count())
        ------------[ cut here ]------------
        WARNING: CPU: 19 PID: 1 at kernel/sched/core.c:3094 preempt_count_sub+0xcc/0x140
        Modules linked in:
        CPU: 19 PID: 1 Comm: swapper/0 Not tainted 4.13.0-rc7-nnr+ #97
        task: c0000000fea80000 task.stack: c0000000feb00000
        NIP:  c00000000011d3dc LR: c00000000011d3d8 CTR: c000000000a090d0
        REGS: c0000000feb03400 TRAP: 0700   Not tainted  (4.13.0-rc7-nnr+)
        MSR:  8000000000021033 <SF,ME,IR,DR,RI,LE>  CR: 28000282  XER: 00000000
        CFAR: c00000000015aa18 SOFTE: 0
        <snip>
        NIP preempt_count_sub+0xcc/0x140
        LR  preempt_count_sub+0xc8/0x140
        Call Trace:
          preempt_count_sub+0xc8/0x140 (unreliable)
          kprobe_handler+0x228/0x4b0
          program_check_exception+0x58/0x3b0
          program_check_common+0x16c/0x170
          --- interrupt: 0 at kprobe_target+0x8/0x20
                           LR = init_test_probes+0x248/0x7d0
          kp+0x0/0x80 (unreliable)
          livepatch_handler+0x38/0x74
          init_kprobes+0x1d8/0x208
          do_one_initcall+0x68/0x1d0
          kernel_init_freeable+0x298/0x374
          kernel_init+0x24/0x160
          ret_from_kernel_thread+0x5c/0x70
        Instruction dump:
        419effdc 3d22001b 39299240 81290000 2f890000 409effc8 3c82ffcb 3c62ffcb
        3884bc68 3863bc18 4803d5fd 60000000 <0fe00000> 4bffffa8 60000000 60000000
        ---[ end trace 432dd46b4ce3d29f ]---
        Kprobe smoke test: passed successfully
      
      The issue is that we aren't disabling preemption in
      kprobe_ftrace_handler(). Disable it.
      
      Fixes: ead514d5 ("powerpc/kprobes: Add support for KPROBES_ON_FTRACE")
      Acked-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
      Signed-off-by: default avatarNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
      [mpe: Trim oops a little for formatting]
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      6baea433
  3. 04 Oct, 2017 18 commits
  4. 03 Oct, 2017 1 commit
  5. 28 Sep, 2017 2 commits
    • Frederic Barrat's avatar
      cxl: Enable global TLBIs for cxl contexts · 03b8abed
      Frederic Barrat authored
      The PSL and nMMU need to see all TLB invalidations for the memory
      contexts used on the adapter. For the hash memory model, it is done by
      making all TLBIs global as soon as the cxl driver is in use. For
      radix, we need something similar, but we can refine and only convert
      to global the invalidations for contexts actually used by the device.
      
      The new mm_context_add_copro() API increments the 'active_cpus' count
      for the contexts attached to the cxl adapter. As soon as there's more
      than 1 active cpu, the TLBIs for the context become global. Active cpu
      count must be decremented when detaching to restore locality if
      possible and to avoid overflowing the counter.
      
      The hash memory model support is somewhat limited, as we can't
      decrement the active cpus count when mm_context_remove_copro() is
      called, because we can't flush the TLB for a mm on hash. So TLBIs
      remain global on hash.
      Signed-off-by: default avatarFrederic Barrat <fbarrat@linux.vnet.ibm.com>
      Fixes: f24be42a ("cxl: Add psl9 specific code")
      Tested-by: default avatarAlistair Popple <alistair@popple.id.au>
      [mpe: Fold in updated comment on the barrier from Fred]
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      03b8abed
    • Frederic Barrat's avatar
      powerpc/mm: Export flush_all_mm() · 6110236b
      Frederic Barrat authored
      With the optimizations introduced by commit a46cc7a9
      ("powerpc/mm/radix: Improve TLB/PWC flushes"), flush_tlb_mm() no
      longer flushes the page walk cache (PWC) with radix. This patch
      introduces flush_all_mm(), which flushes everything, TLB and PWC, for
      a given mm.
      Signed-off-by: default avatarFrederic Barrat <fbarrat@linux.vnet.ibm.com>
      Reviewed-By: default avatarAlistair Popple <alistair@popple.id.au>
      [mpe: Add a WARN_ON_ONCE() in the empty hash routines]
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      6110236b
  6. 26 Sep, 2017 2 commits
    • Michael Neuling's avatar
      powerpc/64s: Add workaround for P9 vector CI load issue · 5080332c
      Michael Neuling authored
      POWER9 DD2.1 and earlier has an issue where some cache inhibited
      vector load will return bad data. The workaround is two part, one
      firmware/microcode part triggers HMI interrupts when hitting such
      loads, the other part is this patch which then emulates the
      instructions in Linux.
      
      The affected instructions are limited to lxvd2x, lxvw4x, lxvb16x and
      lxvh8x.
      
      When an instruction triggers the HMI, all threads in the core will be
      sent to the HMI handler, not just the one running the vector load.
      
      In general, these spurious HMIs are detected by the emulation code and
      we just return back to the running process. Unfortunately, if a
      spurious interrupt occurs on a vector load that's to normal memory we
      have no way to detect that it's spurious (unless we walk the page
      tables, which is very expensive). In this case we emulate the load but
      we need do so using a vector load itself to ensure 128bit atomicity is
      preserved.
      
      Some additional debugfs emulated instruction counters are added also.
      Signed-off-by: default avatarMichael Neuling <mikey@neuling.org>
      Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      [mpe: Switch CONFIG_PPC_BOOK3S_64 to CONFIG_VSX to unbreak the build]
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      5080332c
    • Benjamin Herrenschmidt's avatar
      powerpc/powernv: Rework EEH initialization on powernv · b9fde58d
      Benjamin Herrenschmidt authored
      Remove the post_init callback which is only used
      by powernv, we can just call it explicitly from
      the powernv code.
      
      This partially kills the ability to "disable" eeh at
      runtime via debugfs as this was calling that same
      callback again, but this is both unused and broken
      in several ways. If we want to revive it, we need
      to create a dedicated enable/disable callback on the
      backend that does the right thing.
      
      Let the bulk of eeh initialize normally at
      core_initcall() like it does on pseries by removing
      the hack in eeh_init() that delays it.
      
      Instead we make sure our eeh->probe cleanly bails
      out of the PEs haven't been created yet and we force
      a re-probe where we used to call eeh_init() again.
      Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      Acked-by: default avatarRussell Currey <ruscur@russell.cc>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      b9fde58d
  7. 24 Sep, 2017 11 commits