This patch disables the branch target address CAM which under specific
circumstances may cause the processor to skip execution of 1-4
instructions. This fixes IBM Erratum #47.
Signed-off-by: NAlistair Popple <alistair@popple.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

When we take full hotplug to recover from EEH errors, PCI buses
could be involved. For the case, the child devices of involved
PCI buses can't be attached to IOMMU group properly, which is
caused by commit 3f28c5af ("powerpc/powernv: Reduce multi-hit of
iommu_add_device()").

When adding the PCI devices of the newly created PCI buses to
the system, the IOMMU group is expected to be added in (C).
(A) fails to bind the IOMMU group because bus->is_added is
false. (B) fails because the device doesn't have binding IOMMU
table yet. bus->is_added is set to true at end of (C) and
pdev->is_added is set to true at (D).

   pcibios_add_pci_devices()
      pci_scan_bridge()
         pci_scan_child_bus()
            pci_scan_slot()
               pci_scan_single_device()
                  pci_scan_device()
                  pci_device_add()
                     pcibios_add_device()           A: Ignore
                     device_add()                   B: Ignore
                  pcibios_fixup_bus()
                     pcibios_setup_bus_devices()
                        pcibios_setup_device()      C: Hit
      pcibios_finish_adding_to_bus()
         pci_bus_add_devices()
            pci_bus_add_device()                    D: Add device

If the parent PCI bus isn't involved in hotplug, the IOMMU
group is expected to be bound in (B). (A) should fail as the
sysfs entries aren't populated.

The patch fixes the issue by reverting commit 3f28c5af and remove
WARN_ON() in iommu_add_device() to allow calling the function
even the specified device already has associated IOMMU group.

Cc: <stable@vger.kernel.org>  # 3.16+
Reported-by: NThadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: NWei Yang <weiyang@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Once again, we see

arch/powerpc/kernel/exceptions-64s.S: Assembler messages:
arch/powerpc/kernel/exceptions-64s.S:865: Error: attempt to move .org backwards
arch/powerpc/kernel/exceptions-64s.S:866: Error: attempt to move .org backwards
arch/powerpc/kernel/exceptions-64s.S:890: Error: attempt to move .org backwards

when compiling ppc:allmodconfig.

This time the problem has been caused by to commit 0869b6fd
("powerpc/book3s: Add basic infrastructure to handle HMI in Linux"),
which adds functions hmi_exception_early and hmi_exception_after_realmode
into a critical (size-limited) code area, even though that does not appear
to be necessary.

Move those functions to a non-critical area of the file.
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Replace strict_strto calls with more appropriate kstrto calls
Signed-off-by: NDaniel Walter <dwalter@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The core mm code will provide a default gate area based on
FIXADDR_USER_START and FIXADDR_USER_END if
!defined(__HAVE_ARCH_GATE_AREA) && defined(AT_SYSINFO_EHDR).

This default is only useful for ia64.  arm64, ppc, s390, sh, tile, 64-bit
UML, and x86_32 have their own code just to disable it.  arm, 32-bit UML,
and x86_64 have gate areas, but they have their own implementations.

This gets rid of the default and moves the code into ia64.

This should save some code on architectures without a gate area: it's now
possible to inline the gate_area functions in the default case.
Signed-off-by: NAndy Lutomirski <luto@amacapital.net>
Acked-by: NNathan Lynch <nathan_lynch@mentor.com>
Acked-by: NH. Peter Anvin <hpa@linux.intel.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [in principle]
Acked-by: Richard Weinberger <richard@nod.at> [for um]
Acked-by: Will Deacon <will.deacon@arm.com> [for arm64]
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Nathan Lynch <Nathan_Lynch@mentor.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The function is used by VFIO driver, which might be built as a
dynamic module. So it should be exported.
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Use sigsp() instead of the open coded variant.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Use the more generic functions get_signal() signal_setup_done()
for signal delivery.
This inverts also the return codes of setup_*frame() to follow the
kernel convention.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Some new functions are exposed for use by the IOMMU code but
won't build when CONFIG_IOMMU_API isn't set, so shield them
appropriately.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Some people see things like "Exception: 501" in stack traces in dmesg
and assume that means that something has gone badly wrong, when in
fact "Exception: 501" just means a device interrupt was taken.
This changes "Exception" to "interrupt" to make it clearer that we
are just recording the fact of a change in control flow rather than
some error condition.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

(NOTE: This patch depends on upstream HMI handling patchset at
 https://lists.ozlabs.org/pipermail/linuxppc-dev/2014-July/119731.html)

The current HMI handling on napping cpus does not take care of endianess
issue. On LE host kernel when we wake up from nap due to HMI interrupt we
would checkstop while jumping into opal call. There is a similar issue in
case of fast sleep wakeup where the code invokes opal_resync_tb opal call
without handling LE issue. This patch fixes that as well.

With this patch applied, HMIs handling on LE host kernel works fine.
Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

HMIs are thread specific and can come while thread is in sleep/nap mode.
Hence with SMT=off mode we can receive HMIs on sleeping threads. For
interrupt received in nap mode, cpu wakes up at system reset vector, clears
the interrupt and go back to nap mode again. But HMIs are sticky and they
keep happening until we clear reason bits from HMER. Hence add a special
check for HMI in reset vector (through power7_wakeup_* functions) and
invoke opal call to handle HMI.
Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Handle Hypervisor Maintenance Interrupt (HMI) in Linux. This patch implements
basic infrastructure to handle HMI in Linux host. The design is to invoke
opal handle hmi in real mode for recovery and set irq_pending when we hit HMI.
During check_irq_replay pull opal hmi event and print hmi info on console.
Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

There is a couple of commented debug prints which still use
IOMMU_PAGE_SHIFT() which is not defined for POWERPC anymore, replace
them with it_page_shift.
Signed-off-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The patch allows PE (struct eeh_pe) instance to have auxillary data,
whose size is configurable on basis of platform. For PowerNV, the
auxillary data will be used to cache PHB diag-data for that PE
(frozen PE or fenced PHB). In turn, we can retrieve the diag-data
at any later points.

It's useful for the case of VFIO PCI devices where the error log
should be cached, and then be retrieved by the guest at later point.
Also, it can avoid PHB diag-data overwritting if another frozen PE
reported and the previous diag-data isn't fetched by guest.
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

pr_warn() is equal to pr_warning(), but the former is a bit more
formal according to commit fc62f2f1 ("kernel.h: add pr_warn for
symmetry to dev_warn, netdev_warn").

The patch replaces pr_warning() with pr_warn().
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The patch prints 4 PCIE or AER config registers each line, which
is part of the EEH log so that it looks a bit more compact.
Suggested-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

According to the experiment I did, PCI config access is blocked
on P7IOC frozen PE by hardware, but PHB3 doesn't do that. That
means we always get 0xFF's while dumping PCI config space of the
frozen PE on P7IOC. We don't have the problem on PHB3. So we have
to enable I/O prioir to collecting error log. Otherwise, meaningless
0xFF's are always returned.

The patch fixes it by EEH flag (EEH_ENABLE_IO_FOR_LOG), which is
selectively set to indicate the case for: P7IOC on PowerNV platform,
pSeries platform.
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

There are multiple global EEH flags. Almost each flag has its own
accessor, which doesn't make sense. The patch refactors EEH flag
accessors so that they look unified:

  eeh_add_flag():   Add EEH flag
  eeh_clear_flag(): Clear EEH flag
  eeh_has_flag():   Check if one specific flag has been set
  eeh_enabled():    Check if EEH functionality has been enabled
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Function eeh_iommu_group_to_pe() iterates each PCI device to check
the binding IOMMU group with get_iommu_table_base(), which possibly
fetches pdev->dev.archdata.dma_data.dma_offset. It's (0x1 << 59)
for "bypass" cases.

The patch fixes the issue by iterating devices hooked to the IOMMU
group and fetch IOMMU table there.
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

pci_get_slot() is called with hold of PCI bus semaphore and it's not
safe to be called in interrupt context. However, we possibly checks
EEH error and calls the function in interrupt context. To avoid using
pci_get_slot(), we turn into device tree for fetching location code.
Otherwise, we might run into WARN_ON() as following messages indicate:

 WARNING: at drivers/pci/search.c:223
 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.16.0-rc3+ #72
 task: c000000001367af0 ti: c000000001444000 task.ti: c000000001444000
 NIP: c000000000497b70 LR: c000000000037530 CTR: 000000003003d114
 REGS: c000000001446fa0 TRAP: 0700   Not tainted  (3.16.0-rc3+)
 MSR: 9000000000029032 <SF,HV,EE,ME,IR,DR,RI>  CR: 48002422  XER: 20000000
 CFAR: c00000000003752c SOFTE: 0
   :
 NIP [c000000000497b70] .pci_get_slot+0x40/0x110
 LR [c000000000037530] .eeh_pe_loc_get+0x150/0x190
 Call Trace:
   .of_get_property+0x30/0x60 (unreliable)
   .eeh_pe_loc_get+0x150/0x190
   .eeh_dev_check_failure+0x1b4/0x550
   .eeh_check_failure+0x90/0xf0
   .lpfc_sli_check_eratt+0x504/0x7c0 [lpfc]
   .lpfc_poll_eratt+0x64/0x100 [lpfc]
   .call_timer_fn+0x64/0x190
   .run_timer_softirq+0x2cc/0x3e0

Cc: stable@vger.kernel.org
Signed-off-by: NMike Qiu <qiudayu@linux.vnet.ibm.com>
Acked-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The sysfs entries are lost because of commit 2213fb14 ("powerpc/eeh:
Skip eeh sysfs when eeh is disabled"). That commit added condition
to create sysfs entries with EEH_ENABLED, which isn't populated
when trying to create sysfs entries on PowerNV platform during system
boot time. The patch fixes the issue by:

   * Reoder EEH initialization functions so that they're same on
     PowerNV/pSeries.
   * Cache PE's primary bus by PowerNV platform instead of EEH core
     to avoid kernel crash caused by the function reorder. Another
     benefit with this is to avoid one eeh_probe_mode_dev() in EEH
     core.
Signed-off-by: NMike Qiu <qiudayu@linux.vnet.ibm.com>
Acked-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The patch exports functions to be used by new VFIO ioctl command,
which will be introduced in subsequent patch, to support EEH
functinality for VFIO PCI devices.
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We must not handle EEH error on devices which are passed to somebody
else. Instead, we expect that the frozen device owner detects an EEH
error and recovers from it.

This avoids EEH error handling on passed through devices so the device
owner gets a chance to handle them.
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The general idea is that each core will release all of its
threads into the secondary thread startup code, which will
eventually wait in the secondary core holding area, for the
appropriate bit in the PACA to be set. The kick_cpu function
pointer will set that bit in the PACA, and thus "release"
the core/thread to boot. We also need to do a few things that
U-Boot normally does for CPUs (like enable branch prediction).
Signed-off-by: NAndy Fleming <afleming@freescale.com>
[scottwood@freescale.com: various changes, including only enabling
 threads if Linux wants to kick them]
Signed-off-by: NScott Wood <scottwood@freescale.com>

SPRN_SPRG is used by debug interrupt handler, so this is required for
debug support.
Signed-off-by: NBharat Bhushan <Bharat.Bhushan@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

This provides a way for userspace controls which sPAPR hcalls get
handled in the kernel.  Each hcall can be individually enabled or
disabled for in-kernel handling, except for H_RTAS.  The exception
for H_RTAS is because userspace can already control whether
individual RTAS functions are handled in-kernel or not via the
KVM_PPC_RTAS_DEFINE_TOKEN ioctl, and because the numeric value for
H_RTAS is out of the normal sequence of hcall numbers.

Hcalls are enabled or disabled using the KVM_ENABLE_CAP ioctl for the
KVM_CAP_PPC_ENABLE_HCALL capability on the file descriptor for the VM.
The args field of the struct kvm_enable_cap specifies the hcall number
in args[0] and the enable/disable flag in args[1]; 0 means disable
in-kernel handling (so that the hcall will always cause an exit to
userspace) and 1 means enable.  Enabling or disabling in-kernel
handling of an hcall is effective across the whole VM.

The ability for KVM_ENABLE_CAP to be used on a VM file descriptor
on PowerPC is new, added by this commit.  The KVM_CAP_ENABLE_CAP_VM
capability advertises that this ability exists.

When a VM is created, an initial set of hcalls are enabled for
in-kernel handling.  The set that is enabled is the set that have
an in-kernel implementation at this point.  Any new hcall
implementations from this point onwards should not be added to the
default set without a good reason.

No distinction is made between real-mode and virtual-mode hcall
implementations; the one setting controls them both.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAlexander Graf <agraf@suse.de>

I spent ten minutes scratching my head, trying to work out where we
enabled relocation on interrupts for guest kernels. Expand the doco to
make it clear.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

DISABLE_INTS has a long and storied history, but for some time now it
has not actually disabled interrupts.

For the open-coded exception handlers, just stop using it, instead call
RECONCILE_IRQ_STATE directly. This has the benefit of removing a level
of indirection, and making it clear that r10 & r11 are used at that
point.

For the addition case we still need a macro, so rename it to clarify
what it actually does.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

At the moment the allmodconfig build is failing because we run out of
space between altivec_assist() at 0x5700 and the fwnmi_data_area at
0x7000.

Fixing it permanently will take some more work, but a quick fix is to
move bad_stack() below the fwnmi_data_area. That gives us just enough
room with everything enabled.

bad_stack() is called from the common exception handlers, but it's a
non-conditional branch, so we have plenty of scope to move it further
way.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We have a strange #define in cputable.h called CLASSIC_PPC.

Although it is defined for 32 & 64bit, it's only used for 32bit and
it's basically a duplicate of CONFIG_PPC_BOOK3S_32, so let's use
the latter.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The previous patch left a bit of a wart in copy_process(). Clean it up a
bit by moving the logic out into a helper.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We now only support cpus that use an SLB, so we don't need an MMU
feature to indicate that.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Old cpus didn't have a Segment Lookaside Buffer (SLB), instead they had
a Segment Table (STAB). Now that we've dropped support for those cpus,
we can remove the STAB support entirely.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We inadvertently broke power3 support back in 3.4 with commit
f5339277 "powerpc: Remove FW_FEATURE ISERIES from arch code".
No one noticed until at least 3.9.

By then we'd also broken it with the optimised memcpy, copy_to/from_user
and clear_user routines. We don't want to add any more complexity to
those just to support ancient cpus, so it seems like it's a good time to
drop support for power3 and earlier.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Currently we have sys_sigpending and sys_old_getrlimit defined to use
COMPAT_SYS() in systbl.h, but then both are #defined to sys_ni_syscall
in systbl.S.

This seems to have been done when ppc and ppc64 were merged, in commit
9994a338 "Introduce entry_{32,64}.S, misc_{32,64}.S, systbl.S".

AFAICS there's no longer (or never was) any need for this, we can just
use SYSX() for both and remove the #defines to sys_ni_syscall.

The expansion before was:

  #define COMPAT_SYS(func)	.llong	.sys_##func,.compat_sys_##func
  #define sys_old_getrlimit sys_ni_syscall
  COMPAT_SYS(old_getrlimit)
  =>
  .llong	.sys_old_getrlimit,.compat_sys_old_getrlimit
  =>
  .llong	.sys_ni_syscall,.compat_sys_old_getrlimit

After is:

  #define SYSX(f, f3264, f32)	.llong	.f,.f3264
  SYSX(sys_ni_syscall, compat_sys_old_getrlimit, sys_old_getrlimit)
  =>
  .llong	.sys_ni_syscall,.compat_sys_old_getrlimit

ie. they are equivalent.

Finally both COMPAT_SYS() and SYSX() evaluate to sys_ni_syscall in the
Cell SPU code.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The function rtas_flash_firmware passes the address of a data structure,
flash_block_list, when making the update-flash-64-and-reboot rtas call.
While the endianness of the address is handled correctly, the endianness
of the data is not.  This patch ensures that the data in flash_block_list
is big endian when passed to rtas on little endian hosts.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

cycle_last was added to the clocksource to support the TSC
validation. We moved that to the core code, so we can get rid of the
extra copy.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

These processors do not currently support doorbell IPIs, so remove them
from the feature list if we are at DD 1.xx for the 0x004d part.

This fixes a regression caused by d4e58e59 (powerpc/powernv: Enable
POWER8 doorbell IPIs). With that patch the kernel would hang at boot
when calling smp_call_function_many, as the doorbell would not be
received by the target CPUs:

  .smp_call_function_many+0x2bc/0x3c0 (unreliable)
  .on_each_cpu_mask+0x30/0x100
  .cpuidle_register_driver+0x158/0x1a0
  .cpuidle_register+0x2c/0x110
  .powernv_processor_idle_init+0x23c/0x2c0
  .do_one_initcall+0xd4/0x260
  .kernel_init_freeable+0x25c/0x33c
  .kernel_init+0x1c/0x120
  .ret_from_kernel_thread+0x58/0x7c

Fixes: d4e58e59 (powerpc/powernv: Enable POWER8 doorbell IPIs)
Signed-off-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

ftrace_stop() is going away as it disables parts of function tracing
that affects users that should not be affected. But ftrace_graph_stop()
is built on ftrace_stop(). Here's another example of killing all of
function tracing because something went wrong with function graph
tracing.

Instead of disabling all users of function tracing on function graph
error, disable only function graph tracing. To do this, the arch code
must call ftrace_graph_is_dead() before it implements function graph.

Cc: Anton Blanchard <anton@samba.org>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>