1. 02 Feb, 2015 4 commits
    • Gavin Shan's avatar
      powerpc/kernel: Avoid initializing device-tree pointer twice · fe12545e
      Gavin Shan authored
      As commit 50ba08f3 ("of/fdt: Don't clear initial_boot_params
      if fdt_check_header() fails") does, the device-tree pointer
      "initial_boot_params" is initialized by early_init_dt_verify(),
      which is called by early_init_devtree(). So we needn't explicitly
      initialize that again in early_init_devtree().
      Signed-off-by: default avatarGavin Shan <gwshan@linux.vnet.ibm.com>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      fe12545e
    • Michael Ellerman's avatar
      powerpc: Remove old compile time disabled syscall tracing code · a4bcbe6a
      Michael Ellerman authored
      We have code to do syscall tracing which is disabled at compile time by
      default. It's not been touched since the dawn of time (ie. v2.6.12).
      
      There are now better ways to do syscall tracing, ie. using the
      raw_syscall, or syscall tracepoints.
      
      For the specific case of tracing syscalls at boot on a system that
      doesn't get to userspace, you can boot with:
      
        trace_event=syscalls tp_printk=on
      
      Which will trace syscalls from boot, and echo all output to the console.
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      a4bcbe6a
    • Michael Ellerman's avatar
      powerpc/kernel: Make syscall_exit a local label · 4c3b2168
      Michael Ellerman authored
      Currently when we back trace something that is in a syscall we see
      something like this:
      
      [c000000000000000] [c000000000000000] SyS_read+0x6c/0x110
      [c000000000000000] [c000000000000000] syscall_exit+0x0/0x98
      
      Although it's entirely correct, seeing syscall_exit at the bottom can be
      confusing - we were exiting from a syscall and then called SyS_read() ?
      
      If we instead change syscall_exit to be a local label we get something
      more intuitive:
      
      [c0000001fa46fde0] [c00000000026719c] SyS_read+0x6c/0x110
      [c0000001fa46fe30] [c000000000009264] system_call+0x38/0xd0
      
      ie. we were handling a system call, and it was SyS_read().
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      4c3b2168
    • Ryan Grimm's avatar
      cxl: Fix device_node reference counting · 6f963ec2
      Ryan Grimm authored
      When unbinding and rebinding the driver on a system with a card in PHB0, this
      error condition is reached after a few attempts:
      
      ERROR: Bad of_node_put() on /pciex@3fffe40000000
      CPU: 0 PID: 3040 Comm: bash Not tainted 3.18.0-rc3-12545-g3627ffe #152
      Call Trace:
      [c000000721acb5c0] [c00000000086ef94] .dump_stack+0x84/0xb0 (unreliable)
      [c000000721acb640] [c00000000073a0a8] .of_node_release+0xd8/0xe0
      [c000000721acb6d0] [c00000000044bc44] .kobject_release+0x74/0xe0
      [c000000721acb760] [c0000000007394fc] .of_node_put+0x1c/0x30
      [c000000721acb7d0] [c000000000545cd8] .cxl_probe+0x1a98/0x1d50
      [c000000721acb900] [c0000000004845a0] .local_pci_probe+0x40/0xc0
      [c000000721acb980] [c000000000484998] .pci_device_probe+0x128/0x170
      [c000000721acba30] [c00000000052400c] .driver_probe_device+0xac/0x2a0
      [c000000721acbad0] [c000000000522468] .bind_store+0x108/0x160
      [c000000721acbb70] [c000000000521448] .drv_attr_store+0x38/0x60
      [c000000721acbbe0] [c000000000293840] .sysfs_kf_write+0x60/0xa0
      [c000000721acbc50] [c000000000292500] .kernfs_fop_write+0x140/0x1d0
      [c000000721acbcf0] [c000000000208648] .vfs_write+0xd8/0x260
      [c000000721acbd90] [c000000000208b18] .SyS_write+0x58/0x100
      [c000000721acbe30] [c000000000009258] syscall_exit+0x0/0x98
      
      We are missing a call to of_node_get(). pnv_pci_to_phb_node() should
      call of_node_get() otherwise np's reference count isn't incremented and
      it might go away. Rename pnv_pci_to_phb_node() to pnv_pci_get_phb_node()
      so it's clear it calls of_node_get().
      Signed-off-by: default avatarRyan Grimm <grimm@linux.vnet.ibm.com>
      Acked-by: default avatarIan Munsie <imunsie@au1.ibm.com>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      6f963ec2
  2. 28 Jan, 2015 7 commits
  3. 27 Jan, 2015 2 commits
    • Pranith Kumar's avatar
      powerpc/powernv: Skip registering log region when CONFIG_PRINTK=n · 6501ab5e
      Pranith Kumar authored
      When CONFIG_PRINTK=n, log_buf_addr_get() returns NULL and log_buf_len_get()
      return 0. Check for these return values and skip registering the dump buffer.
      Signed-off-by: default avatarPranith Kumar <bobby.prani@gmail.com>
      Reviewed-by: default avatarStewart Smith <stewart@linux.vnet.ibm.com>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      6501ab5e
    • Cyril Bur's avatar
      powerpc/pseries: Fix endian problems with LE migration · 3df76a9d
      Cyril Bur authored
      RTAS events require arguments be passed in big endian while hypercalls
      have their arguments passed in registers and the values should therefore
      be in CPU endian.
      
      The "ibm,suspend_me" 'RTAS' call makes a sequence of hypercalls to setup
      one true RTAS call. This means that "ibm,suspend_me" is handled
      specially in the ppc_rtas() syscall.
      
      The ppc_rtas() syscall has its arguments in big endian and can therefore
      pass these arguments directly to the RTAS call. "ibm,suspend_me" is
      handled specially from within ppc_rtas() (by calling rtas_ibm_suspend_me())
      which has left an endian bug on little endian systems due to the
      requirement of hypercalls. The return value from rtas_ibm_suspend_me()
      gets returned in cpu endian, and is left unconverted, also a bug on
      little endian systems.
      
      rtas_ibm_suspend_me() does not actually make use of the rtas_args that
      it is passed. This patch removes the convoluted use of the rtas_args
      struct to pass params to rtas_ibm_suspend_me() in favour of passing what
      it needs as actual arguments. This patch also ensures the two callers of
      rtas_ibm_suspend_me() pass function parameters in cpu endian and in the
      case of ppc_rtas(), converts the return value.
      
      migrate_store() (the other caller of rtas_ibm_suspend_me()) is from a
      sysfs file which deals with everything in cpu endian so this function
      only underwent cleanup.
      
      This patch has been tested with KVM both LE and BE and on PowerVM both
      LE and BE. Under QEMU/KVM the migration happens without touching these
      code pathes.
      
      For PowerVM there is no obvious regression on BE and the LE code path
      now provides the correct parameters to the hypervisor.
      Signed-off-by: default avatarCyril Bur <cyrilbur@gmail.com>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      3df76a9d
  4. 23 Jan, 2015 17 commits
  5. 22 Jan, 2015 10 commits