linux-toradex.git/arch/powerpc, branch v3.10.41

powerpc: Add vr save/restore functions

2014-05-31T04:52:12+00:00

commit 8fe9c93e7453e67b8bd09f263ec1bb0783c733fc upstream.

GCC 4.8 now generates out-of-line vr save/restore functions when
optimizing for size.  They are needed for the raid6 altivec support.

Signed-off-by: Andreas Schwab 
Signed-off-by: Benjamin Herrenschmidt 
Cc: Guenter Roeck 
Signed-off-by: Greg Kroah-Hartman

powerpc/tm: Disable IRQ in tm_recheckpoint

2014-05-13T11:59:42+00:00

commit e6b8fd028b584ffca7a7255b8971f254932c9fce upstream.

We can't take an IRQ when we're about to do a trechkpt as our GPR state is set
to user GPR values.

We've hit this when running some IBM Java stress tests in the lab resulting in
the following dump:

  cpu 0x3f: Vector: 700 (Program Check) at [c000000007eb3d40]
      pc: c000000000050074: restore_gprs+0xc0/0x148
      lr: 00000000b52a8184
      sp: ac57d360
     msr: 8000000100201030
    current = 0xc00000002c500000
    paca    = 0xc000000007dbfc00     softe: 0     irq_happened: 0x00
      pid   = 34535, comm = Pooled Thread #
  R00 = 00000000b52a8184   R16 = 00000000b3e48fda
  R01 = 00000000ac57d360   R17 = 00000000ade79bd8
  R02 = 00000000ac586930   R18 = 000000000fac9bcc
  R03 = 00000000ade60000   R19 = 00000000ac57f930
  R04 = 00000000f6624918   R20 = 00000000ade79be8
  R05 = 00000000f663f238   R21 = 00000000ac218a54
  R06 = 0000000000000002   R22 = 000000000f956280
  R07 = 0000000000000008   R23 = 000000000000007e
  R08 = 000000000000000a   R24 = 000000000000000c
  R09 = 00000000b6e69160   R25 = 00000000b424cf00
  R10 = 0000000000000181   R26 = 00000000f66256d4
  R11 = 000000000f365ec0   R27 = 00000000b6fdcdd0
  R12 = 00000000f66400f0   R28 = 0000000000000001
  R13 = 00000000ada71900   R29 = 00000000ade5a300
  R14 = 00000000ac2185a8   R30 = 00000000f663f238
  R15 = 0000000000000004   R31 = 00000000f6624918
  pc  = c000000000050074 restore_gprs+0xc0/0x148
  cfar= c00000000004fe28 dont_restore_vec+0x1c/0x1a4
  lr  = 00000000b52a8184
  msr = 8000000100201030   cr  = 24804888
  ctr = 0000000000000000   xer = 0000000000000000   trap =  700

This moves tm_recheckpoint to a C function and moves the tm_restore_sprs into
that function.  It then adds IRQ disabling over the trechkpt critical section.
It also sets the TEXASR FS in the signals code to ensure this is never set now
that we explictly write the TM sprs in tm_recheckpoint.

Signed-off-by: Michael Neuling 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc/compat: 32-bit little endian machine name is ppcle, not ppc

2014-05-13T11:59:42+00:00

commit 422b9b9684db3c511e65c91842275c43f5910ae9 upstream.

I noticed this when testing setarch. No, we don't magically
support a big endian userspace on a little endian kernel.

Signed-off-by: Anton Blanchard 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc: Align p_dyn, p_rela and p_st symbols

2014-03-24T04:38:14+00:00

commit a5b2cf5b1af424ee3dd9e3ce6d5cea18cb927e67 upstream.

The 64bit relocation code places a few symbols in the text segment.
These symbols are only 4 byte aligned where they need to be 8 byte
aligned. Add an explicit alignment.

Signed-off-by: Anton Blanchard 
Tested-by: Laurent Dufour 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc/crashdump : Fix page frame number check in copy_oldmem_page

2014-03-07T05:30:08+00:00

commit f5295bd8ea8a65dc5eac608b151386314cb978f1 upstream.

In copy_oldmem_page, the current check using max_pfn and min_low_pfn to
decide if the page is backed or not, is not valid when the memory layout is
not continuous.

This happens when running as a QEMU/KVM guest, where RTAS is mapped higher
in the memory. In that case max_pfn points to the end of RTAS, and a hole
between the end of the kdump kernel and RTAS is not backed by PTEs. As a
consequence, the kdump kernel is crashing in copy_oldmem_page when accessing
in a direct way the pages in that hole.

This fix relies on the memblock's service memblock_is_region_memory to
check if the read page is part or not of the directly accessible memory.

Signed-off-by: Laurent Dufour 
Tested-by: Mahesh Salgaonkar 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc/le: Ensure that the 'stop-self' RTAS token is handled correctly

2014-03-07T05:30:08+00:00

commit 41dd03a94c7d408d2ef32530545097f7d1befe5c upstream.

Currently we're storing a host endian RTAS token in
rtas_stop_self_args.token.  We then pass that directly to rtas.  This is
fine on big endian however on little endian the token is not what we
expect.

This will typically result in hitting:
	panic("Alas, I survived.\n");

To fix this we always use the stop-self token in host order and always
convert it to be32 before passing this to rtas.

Signed-off-by: Tony Breeds 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc: Make sure "cache" directory is removed when offlining cpu

2014-02-06T19:08:18+00:00

commit 91b973f90c1220d71923e7efe1e61f5329806380 upstream.

The code in remove_cache_dir() is supposed to remove the "cache"
subdirectory from the sysfs directory for a CPU when that CPU is
being offlined.  It tries to do this by calling kobject_put() on
the kobject for the subdirectory.  However, the subdirectory only
gets removed once the last reference goes away, and the reference
being put here may well not be the last reference.  That means
that the "cache" subdirectory may still exist when the offlining
operation has finished.  If the same CPU subsequently gets onlined,
the code tries to add a new "cache" subdirectory.  If the old
subdirectory has not yet been removed, we get a WARN_ON in the
sysfs code, with stack trace, and an error message printed on the
console.  Further, we ultimately end up with an online cpu with no
"cache" subdirectory.

This fixes it by doing an explicit kobject_del() at the point where
we want the subdirectory to go away.  kobject_del() removes the sysfs
directory even though the object still exists in memory.  The object
will get freed at some point in the future.  A subsequent onlining
operation can create a new sysfs directory, even if the old object
still exists in memory, without causing any problems.

Signed-off-by: Paul Mackerras 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc: Fix the setup of CPU-to-Node mappings during CPU online

2014-02-06T19:08:18+00:00

commit d4edc5b6c480a0917e61d93d55531d7efa6230be upstream.

On POWER platforms, the hypervisor can notify the guest kernel about dynamic
changes in the cpu-numa associativity (VPHN topology update). Hence the
cpu-to-node mappings that we got from the firmware during boot, may no longer
be valid after such updates. This is handled using the arch_update_cpu_topology()
hook in the scheduler, and the sched-domains are rebuilt according to the new
mappings.

But unfortunately, at the moment, CPU hotplug ignores these updated mappings
and instead queries the firmware for the cpu-to-numa relationships and uses
them during CPU online. So the kernel can end up assigning wrong NUMA nodes
to CPUs during subsequent CPU hotplug online operations (after booting).

Further, a particularly problematic scenario can result from this bug:
On POWER platforms, the SMT mode can be switched between 1, 2, 4 (and even 8)
threads per core. The switch to Single-Threaded (ST) mode is performed by
offlining all except the first CPU thread in each core. Switching back to
SMT mode involves onlining those other threads back, in each core.

Now consider this scenario:

1. During boot, the kernel gets the cpu-to-node mappings from the firmware
   and assigns the CPUs to NUMA nodes appropriately, during CPU online.

2. Later on, the hypervisor updates the cpu-to-node mappings dynamically and
   communicates this update to the kernel. The kernel in turn updates its
   cpu-to-node associations and rebuilds its sched domains. Everything is
   fine so far.

3. Now, the user switches the machine from SMT to ST mode (say, by running
   ppc64_cpu --smt=1). This involves offlining all except 1 thread in each
   core.

4. The user then tries to switch back from ST to SMT mode (say, by running
   ppc64_cpu --smt=4), and this involves onlining those threads back. Since
   CPU hotplug ignores the new mappings, it queries the firmware and tries to
   associate the newly onlined sibling threads to the old NUMA nodes. This
   results in sibling threads within the same core getting associated with
   different NUMA nodes, which is incorrect.

   The scheduler's build-sched-domains code gets thoroughly confused with this
   and enters an infinite loop and causes soft-lockups, as explained in detail
   in commit 3be7db6ab (powerpc: VPHN topology change updates all siblings).

So to fix this, use the numa_cpu_lookup_table to remember the updated
cpu-to-node mappings, and use them during CPU hotplug online operations.
Further, we also need to ensure that all threads in a core are assigned to a
common NUMA node, irrespective of whether all those threads were online during
the topology update. To achieve this, we take care not to use cpu_sibling_mask()
since it is not hotplug invariant. Instead, we use cpu_first_sibling_thread()
and set up the mappings manually using the 'threads_per_core' value for that
particular platform. This helps us ensure that we don't hit this bug with any
combination of CPU hotplug and SMT mode switching.

Signed-off-by: Srivatsa S. Bhat 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

KVM: PPC: e500: Fix bad address type in deliver_tlb_misss()

2014-02-06T19:08:17+00:00

commit 70713fe315ed14cd1bb07d1a7f33e973d136ae3d upstream.

Use gva_t instead of unsigned int for eaddr in deliver_tlb_miss().

Signed-off-by: Mihai Caraman 
Signed-off-by: Alexander Graf 
Signed-off-by: Greg Kroah-Hartman

KVM: PPC: Book3S HV: use xics_wake_cpu only when defined

2014-02-06T19:08:17+00:00

commit 48eaef0518a565d3852e301c860e1af6a6db5a84 upstream.

Signed-off-by: Andreas Schwab 
Signed-off-by: Alexander Graf 
Signed-off-by: Greg Kroah-Hartman