1. 20 Apr, 2018 2 commits
    • Linus Torvalds's avatar
      Merge tag 'powerpc-4.17-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux · d08de37b
      Linus Torvalds authored
      Pull powerpc fixes from Michael Ellerman:
      
       - Fix an off-by-one bug in our alternative asm patching which leads to
         incorrectly patched code. This bug lay dormant for nearly 10 years
         but we finally hit it due to a recent change.
      
       - Fix lockups when running KVM guests on Power8 due to a missing check
         when a thread that's running KVM comes out of idle.
      
       - Fix an out-of-spec behaviour in the XIVE code (P9 interrupt
         controller).
      
       - Fix EEH handling of bridge MMIO windows.
      
       - Prevent crashes in our RFI fallback flush handler if firmware didn't
         tell us the size of the L1 cache (only seen on simulators).
      
      Thanks to: Benjamin Herrenschmidt, Madhavan Srinivasan, Michael Neuling.
      
      * tag 'powerpc-4.17-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
        powerpc/kvm: Fix lockups when running KVM guests on Power8
        powerpc/eeh: Fix enabling bridge MMIO windows
        powerpc/xive: Fix trying to "push" an already active pool VP
        powerpc/64s: Default l1d_size to 64K in RFI fallback flush
        powerpc/lib: Fix off-by-one in alternate feature patching
      d08de37b
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux · c2d94c52
      Linus Torvalds authored
      Pull s390 fixes and kexec-file-load from Martin Schwidefsky:
       "After the common code kexec patches went in via Andrew we can now push
        the architecture parts to implement the kexec-file-load system call.
      
        Plus a few more bug fixes and cleanups, this includes an update to the
        default configurations"
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
        s390/signal: cleanup uapi struct sigaction
        s390: rename default_defconfig to debug_defconfig
        s390: remove gcov defconfig
        s390: update defconfig
        s390: add support for IBM z14 Model ZR1
        s390: remove couple of duplicate includes
        s390/boot: remove unused COMPILE_VERSION and ccflags-y
        s390/nospec: include cpu.h
        s390/decompressor: Ignore file vmlinux.bin.full
        s390/kexec_file: add generated files to .gitignore
        s390/Kconfig: Move kexec config options to "Processor type and features"
        s390/kexec_file: Add ELF loader
        s390/kexec_file: Add crash support to image loader
        s390/kexec_file: Add image loader
        s390/kexec_file: Add kexec_file_load system call
        s390/kexec_file: Add purgatory
        s390/kexec_file: Prepare setup.h for kexec_file_load
        s390/smsgiucv: disable SMSG on module unload
        s390/sclp: avoid potential usage of uninitialized value
      c2d94c52
  2. 19 Apr, 2018 2 commits
    • Michael Ellerman's avatar
      powerpc/kvm: Fix lockups when running KVM guests on Power8 · 56376c58
      Michael Ellerman authored
      When running KVM guests on Power8 we can see a lockup where one CPU
      stops responding. This often leads to a message such as:
      
        watchdog: CPU 136 detected hard LOCKUP on other CPUs 72
        Task dump for CPU 72:
        qemu-system-ppc R  running task    10560 20917  20908 0x00040004
      
      And then backtraces on other CPUs, such as:
      
        Task dump for CPU 48:
        ksmd            R  running task    10032  1519      2 0x00000804
        Call Trace:
          ...
          --- interrupt: 901 at smp_call_function_many+0x3c8/0x460
              LR = smp_call_function_many+0x37c/0x460
          pmdp_invalidate+0x100/0x1b0
          __split_huge_pmd+0x52c/0xdb0
          try_to_unmap_one+0x764/0x8b0
          rmap_walk_anon+0x15c/0x370
          try_to_unmap+0xb4/0x170
          split_huge_page_to_list+0x148/0xa30
          try_to_merge_one_page+0xc8/0x990
          try_to_merge_with_ksm_page+0x74/0xf0
          ksm_scan_thread+0x10ec/0x1ac0
          kthread+0x160/0x1a0
          ret_from_kernel_thread+0x5c/0x78
      
      This is caused by commit 8c1c7fb0 ("powerpc/64s/idle: avoid sync
      for KVM state when waking from idle"), which added a check in
      pnv_powersave_wakeup() to see if the kvm_hstate.hwthread_state is
      already set to KVM_HWTHREAD_IN_KERNEL, and if so to skip the store and
      test of kvm_hstate.hwthread_req.
      
      The problem is that the primary does not set KVM_HWTHREAD_IN_KVM when
      entering the guest, so it can then come out to cede with
      KVM_HWTHREAD_IN_KERNEL set. It can then go idle in kvm_do_nap after
      setting hwthread_req to 1, but because hwthread_state is still
      KVM_HWTHREAD_IN_KERNEL we will skip the test of hwthread_req when we
      wake up from idle and won't go to kvm_start_guest. From there the
      thread will return somewhere garbage and crash.
      
      Fix it by skipping the store of hwthread_state, but not the test of
      hwthread_req, when coming out of idle. It's OK to skip the sync in
      that case because hwthread_req will have been set on the same thread,
      so there is no synchronisation required.
      
      Fixes: 8c1c7fb0 ("powerpc/64s/idle: avoid sync for KVM state when waking from idle")
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      56376c58
    • Michael Neuling's avatar
      powerpc/eeh: Fix enabling bridge MMIO windows · 13a83eac
      Michael Neuling authored
      On boot we save the configuration space of PCIe bridges. We do this so
      when we get an EEH event and everything gets reset that we can restore
      them.
      
      Unfortunately we save this state before we've enabled the MMIO space
      on the bridges. Hence if we have to reset the bridge when we come back
      MMIO is not enabled and we end up taking an PE freeze when the driver
      starts accessing again.
      
      This patch forces the memory/MMIO and bus mastering on when restoring
      bridges on EEH. Ideally we'd do this correctly by saving the
      configuration space writes later, but that will have to come later in
      a larger EEH rewrite. For now we have this simple fix.
      
      The original bug can be triggered on a boston machine by doing:
        echo 0x8000000000000000 > /sys/kernel/debug/powerpc/PCI0001/err_injct_outbound
      On boston, this PHB has a PCIe switch on it.  Without this patch,
      you'll see two EEH events, 1 expected and 1 the failure we are fixing
      here. The second EEH event causes the anything under the PHB to
      disappear (i.e. the i40e eth).
      
      With this patch, only 1 EEH event occurs and devices properly recover.
      
      Fixes: 652defed ("powerpc/eeh: Check PCIe link after reset")
      Cc: stable@vger.kernel.org # v3.11+
      Reported-by: default avatarPridhiviraj Paidipeddi <ppaidipe@linux.vnet.ibm.com>
      Signed-off-by: default avatarMichael Neuling <mikey@neuling.org>
      Acked-by: default avatarRussell Currey <ruscur@russell.cc>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      13a83eac
  3. 18 Apr, 2018 2 commits
  4. 17 Apr, 2018 2 commits
    • Madhavan Srinivasan's avatar
      powerpc/64s: Default l1d_size to 64K in RFI fallback flush · 9dfbf78e
      Madhavan Srinivasan authored
      If there is no d-cache-size property in the device tree, l1d_size could
      be zero. We don't actually expect that to happen, it's only been seen
      on mambo (simulator) in some configurations.
      
      A zero-size l1d_size leads to the loop in the asm wrapping around to
      2^64-1, and then walking off the end of the fallback area and
      eventually causing a page fault which is fatal.
      
      Just default to 64K which is correct on some CPUs, and sane enough to
      not cause a crash on others.
      
      Fixes: aa8a5e00 ('powerpc/64s: Add support for RFI flush of L1-D cache')
      Signed-off-by: default avatarMadhavan Srinivasan <maddy@linux.vnet.ibm.com>
      [mpe: Rewrite comment and change log]
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      9dfbf78e
    • Martin Schwidefsky's avatar
      s390/signal: cleanup uapi struct sigaction · fae76491
      Martin Schwidefsky authored
      The struct sigaction for user space in arch/s390/include/uapi/asm/signal.h
      is ill defined. The kernel uses two structures 'struct sigaction' and
      'struct old_sigaction', the correlation in the kernel for both 31 and
      64 bit is as follows
      
          sys_sigaction -> struct old_sigaction
          sys_rt_sigaction -> struct sigaction
      
      The correlation of the (single) uapi definition for 'struct sigaction'
      under '#ifndef __KERNEL__':
      
          31-bit: sys_sigaction -> uapi struct sigaction
          31-bit: sys_rt_sigaction -> no structure available
      
          64-bit: sys_sigaction -> no structure available
          64-bit: sys_rt_sigaction -> uapi struct sigaction
      
      This is quite confusing. To make it a bit less confusing make the
      uapi definition of 'struct sigaction' usable for sys_rt_sigaction for
      both 31-bit and 64-bit.
      Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      fae76491
  5. 16 Apr, 2018 32 commits