If you are using a 64-bit kernel with 32-bit userland, then
scripts/gcc-x86_64-has-stack-protector.sh invokes 32-bit gcc
with -mcmodel=kernel, which produces:

<stdin>:1:0: error: code model 'kernel' not supported in the 32 bit mode

and trips the "broken compiler" test at arch/x86/Makefile:120.

There are several places a fix is possible, but the following seems
cleanest.  (But it's minimal; it would also be possible to factor
out a bunch of stuff from the two branches of the if.)

Signed-off-by: George Spelvin <linux@horizon.com>
Link: http://lkml.kernel.org/r/20140507210552.7581.qmail@ns.horizon.com


Cc: <stable@vger.kernel.org> # v3.14
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

Certec BPC600 needs reboot=pci to actually reboot.

Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Li Aubrey <aubrey.li@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Jones <davej@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1399446114-2147-1-git-send-email-christian.gmeiner@gmail.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>

As requested by Linus add explicit __visible to the asmlinkage users.
This marks all functions visible to assembler.

Tree sweep for arch/x86/*

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1398984278-29319-3-git-send-email-andi@firstfloor.org


Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

arch/x86/crypto/sha1_avx2_x86_64_asm.S introduced _end as a local
symbol, which broke the build under certain circumstances.  Although
the wisdom of _end as a local symbol can definitely be questioned, the
build should not break for that reason.

Thus, filter the output of nm to only get global symbols of
appropriate type.

Reported-by: Andy Lutomirski <luto@amacapital.net>
Cc: Chandramouli Narayanan <mouli@linux.intel.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/n/tip-uxm3j3w3odglcwhafwq5tjqu@git.kernel.org

earlyprintk=efi,keep will cause kernel hangs while freeing initmem like
below:

  VFS: Mounted root (ext4 filesystem) readonly on device 254:2.
  devtmpfs: mounted
  Freeing unused kernel memory: 880K (ffffffff817d4000 - ffffffff818b0000)

It is caused by efi earlyprintk use __init function which will be freed
later.  Such as early_efi_write is marked as __init, also it will use
early_ioremap which is init function as well.

To fix this issue, I added early initcall early_efi_map_fb which maps
the whole efi fb for later use. OTOH, adding a wrapper function
early_efi_map which calls early_ioremap before ioremap is available.

With this patch applied efi boot ok with earlyprintk=efi,keep console=efi

Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

Signed-off-by: Helge Deller <deller@gmx.de>

There are only a couple of architectures that override _STK_LIM_MAX to
a non-infinity value. This changes the stack allocation semantics in
subtle ways. For example, GNU make changes its stack allocation to the
hard maximum defined by _STK_LIM_MAX. As a results, threads executed
by processes running under make are allocated a stack size of
_STK_LIM_MAX rather than a sensible default value. This causes various
thread stress tests to fail when they can't muster more than about 50
threads.

The attached change implements the default behavior used by the
majority of architectures.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Reviewed-by: Carlos O'Donell <carlos@systemhalted.org>
Cc: stable@vger.kernel.org # 3.14
Signed-off-by: Helge Deller <deller@gmx.de>

Commit 93ea02bb ("arch: Clean up asm/barrier.h implementations")
wired generic barrier.h for hexagon, but failed to delete the existing
file.

Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Compile-tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

There was a very small race window where resume to kernel mode from a
Exception Path (or pure kernel mode which is true for most of ARC
exceptions anyways), was not disabling interrupts in restore_regs,
clobbering the exception regs

Anton found the culprit call flow (after many sleepless nights)

| 1. we got a Trap from user land
| 2. started to service it.
| 3. While doing some stuff on user-land memory (I think it is padzero()),
|     we got a DataTlbMiss
| 4. On return from it we are taking "resume_kernel_mode" path
| 5. NEED_RESHED is not set, so we go to "return from exception" path in
|     restore regs.
| 6. there seems to be IRQ happening

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: <stable@vger.kernel.org>   #3.10, 3.12, 3.13, 3.14
Cc: Anton Kolesov <Anton.Kolesov@synopsys.com>
Cc: Francois Bedard <Francois.Bedard@synopsys.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The kvm/mmu code shared by arm and arm64 uses kalloc() to allocate
a bounce page (if hypervisor init code crosses page boundary) and
hypervisor PGDs. The problem is that kalloc() does not guarantee
the proper alignment. In the case of the bounce page, the page sized
buffer allocated may also cross a page boundary negating the purpose
and leading to a hang during kvm initialization. Likewise the PGDs
allocated may not meet the minimum alignment requirements of the
underlying MMU. This patch uses __get_free_page() to guarantee the
worst case alignment needs of the bounce page and PGDs on both arm
and arm64.

Cc: <stable@vger.kernel.org> # 3.10+
Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

On x86 the allocation of irq descriptors may allocate interrupts which
are in the range of the GSI interrupts. That's wrong as those
interrupts are hardwired and we don't have the irq domain translation
like PPC. So one of these interrupts can be hooked up later to one of
the devices which are hard wired to it and the io_apic init code for
that particular interrupt line happily reuses that descriptor with a
completely different configuration so hell breaks lose.

Inside x86 we allocate dynamic interrupts from above nr_gsi_irqs,
except for a few usage sites which have not yet blown up in our face
for whatever reason. But for drivers which need an irq range, like the
GPIO drivers, we have no limit in place and we don't want to expose
such a detail to a driver.

To cure this introduce a function which an architecture can implement
to impose a lower bound on the dynamic interrupt allocations.

Implement it for x86 and set the lower bound to nr_gsi_irqs, which is
the end of the hardwired interrupt space, so all dynamic allocations
happen above.

That not only allows the GPIO driver to work sanely, it also protects
the bogus callsites of create_irq_nr() in hpet, uv, irq_remapping and
htirq code. They need to be cleaned up as well, but that's a separate
issue.

Reported-by: Jin Yao <yao.jin@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Krogerus Heikki <heikki.krogerus@intel.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1404241617360.28206@ionos.tec.linutronix.de


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

We track shadow vmcs fields through two static lists,
one for read only and another for r/w fields. However, with
addition of new vmcs fields, not all fields may be supported on
all hosts. If so, copy_vmcs12_to_shadow() trying to vmwrite on
unsupported hosts will result in a vmwrite error. For example, commit
36be0b9d introduced GUEST_BNDCFGS, which is not supported
by all processors. Filter out host unsupported fields before
letting guests use shadow vmcs

Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Correct IRQ routing in case a vSMP box is detected
but the  Interrupt Routing Comply (IRC) value is set to
"comply", which leads to incorrect IRQ routing.

Before the patch:

When a vSMP box was detected and IRC was set to "comply",
users (and the kernel) couldn't effectively set the
destination of the IRQs. This is because the hook inside
vsmp_64.c always setup all CPUs as the IRQ destination using
cpumask_setall() as the return value for IRQ allocation mask.
Later, this "overrided" mask caused the kernel to set the IRQ
destination to the lowest online CPU in the mask (CPU0 usually).

After the patch:

When the IRC is set to "comply", users (and the kernel) can control
the destination of the IRQs as we will not be changing the
default "apic->vector_allocation_domain".

Signed-off-by: Oren Twaig <oren@scalemp.com>
Acked-by: Shai Fultheim <shai@scalemp.com>
Link: http://lkml.kernel.org/r/1398669697-2123-1-git-send-email-oren@scalemp.com


[ Minor readability edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>

This patch fixes this section mismatch:

WARNING: vmlinux.o(.text+0x1efc4): Section mismatch in reference from
the function apm821xx_pciex_init_port_hw() to the function
.init.text:ppc4xx_pciex_wait_on_sdr.isra.9()

The function apm821xx_pciex_init_port_hw() references the function
__init ppc4xx_pciex_wait_on_sdr.isra.9().  This is often because
apm821xx_pciex_init_port_hw lacks a __init annotation or the
annotation of ppc4xx_pciex_wait_on_sdr.isra.9 is wrong.

apm821xx_pciex_init_port_hw is only referenced by a struct in
__initdata, so it should be safe to add __init to
apm821xx_pciex_init_port_hw.

Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

When the guest cedes the vcpu or the vcpu has no guest to
run it naps. Clear the runlatch bit of the vcpu before
napping to indicate an idle cpu.

Signed-off-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

The secondary threads in the core are kept offline before launching guests
in kvm on powerpc: "371fefd6:KVM: PPC: Allow book3s_hv guests to use
SMT processor modes."

Hence their runlatch bits are cleared. When the secondary threads are called
in to start a guest, their runlatch bits need to be set to indicate that they
are busy. The primary thread has its runlatch bit set though, but there is no
harm in setting this bit once again. Hence set the runlatch bit for all
threads before they start guest.

Signed-off-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Up until now we have been setting the runlatch bits for a busy CPU and
clearing it when a CPU enters idle state. The runlatch bit has thus
been consistent with the utilization of a CPU as long as the CPU is online.

However when a CPU is hotplugged out the runlatch bit is not cleared. It
needs to be cleared to indicate an unused CPU. Hence this patch has the
runlatch bit cleared for an offline CPU just before entering an idle state
and sets it immediately after it exits the idle state.

Signed-off-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

While testing memory hot-remove, I found following dead lock:

Process #1141 is drmgr, trying to remove some memory, i.e. memory499.
It holds the memory_hotplug_mutex, and blocks when trying to remove file
"online" under dir memory499, in kernfs_drain(), at
        wait_event(root->deactivate_waitq,
                   atomic_read(&kn->active) == KN_DEACTIVATED_BIAS);

Process #1120 is trying to online memory499 by
   echo 1 > memory499/online

In .kernfs_fop_write, it uses kernfs_get_active() to increase
&kn->active, thus blocking process #1141. While itself is blocked later
when trying to acquire memory_hotplug_mutex, which is held by process

The backtrace of both processes are shown below:

[<c000000001b18600>] 0xc000000001b18600
[<c000000000015044>] .__switch_to+0x144/0x200
[<c000000000263ca4>] .online_pages+0x74/0x7b0
[<c00000000055b40c>] .memory_subsys_online+0x9c/0x150
[<c00000000053cbe8>] .device_online+0xb8/0x120
[<c00000000053cd04>] .online_store+0xb4/0xc0
[<c000000000538ce4>] .dev_attr_store+0x64/0xa0
[<c00000000030f4ec>] .sysfs_kf_write+0x7c/0xb0
[<c00000000030e574>] .kernfs_fop_write+0x154/0x1e0
[<c000000000268450>] .vfs_write+0xe0/0x260
[<c000000000269144>] .SyS_write+0x64/0x110
[<c000000000009ffc>] syscall_exit+0x0/0x7c

[<c000000001b18600>] 0xc000000001b18600
[<c000000000015044>] .__switch_to+0x144/0x200
[<c00000000030be14>] .__kernfs_remove+0x204/0x300
[<c00000000030d428>] .kernfs_remove_by_name_ns+0x68/0xf0
[<c00000000030fb38>] .sysfs_remove_file_ns+0x38/0x60
[<c000000000539354>] .device_remove_attrs+0x54/0xc0
[<c000000000539fd8>] .device_del+0x158/0x250
[<c00000000053a104>] .device_unregister+0x34/0xa0
[<c00000000055bc14>] .unregister_memory_section+0x164/0x170
[<c00000000024ee18>] .__remove_pages+0x108/0x4c0
[<c00000000004b590>] .arch_remove_memory+0x60/0xc0
[<c00000000026446c>] .remove_memory+0x8c/0xe0
[<c00000000007f9f4>] .pseries_remove_memblock+0xd4/0x160
[<c00000000007fcfc>] .pseries_memory_notifier+0x27c/0x290
[<c0000000008ae6cc>] .notifier_call_chain+0x8c/0x100
[<c0000000000d858c>] .__blocking_notifier_call_chain+0x6c/0xe0
[<c00000000071ddec>] .of_property_notify+0x7c/0xc0
[<c00000000071ed3c>] .of_update_property+0x3c/0x1b0
[<c0000000000756cc>] .ofdt_write+0x3dc/0x740
[<c0000000002f60fc>] .proc_reg_write+0xac/0x110
[<c000000000268450>] .vfs_write+0xe0/0x260
[<c000000000269144>] .SyS_write+0x64/0x110
[<c000000000009ffc>] syscall_exit+0x0/0x7c

This patch uses lock_device_hotplug() to protect remove_memory() called
in pseries_remove_memblock(), which is also stated before function
remove_memory():

 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug
 * and online/offline operations before this call, as required by
 * try_offline_node().
 */
void __ref remove_memory(int nid, u64 start, u64 size)

With this lock held, the other process(#1120 above) trying to online the
memory block will retry the system call when calling
lock_device_hotplug_sysfs(), and finally find No such device error.

Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

module_init should return 0 or a negative errno.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Bump the boot wrapper BOOT_COMMAND_LINE_SIZE to match the
kernel.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

I've had a report that the current limit is too small for
an automated network based installer. Bump it.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

We have two definitions of COMMAND_LINE_SIZE, one for the kernel
and one for the boot wrapper. I assume this is so the boot
wrapper can be self sufficient and not rely on kernel headers.

Having two defines with the same name is confusing, I just
updated the wrong one when trying to bump it.

Make the boot wrapper define unique by calling it
BOOT_COMMAND_LINE_SIZE.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

The catalog version number was changed from a be32 (with proceeding
32bits of padding) to a be64, update the code to treat it as a be64

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

fixup for "powerpc/perf: Add support for the hv gpci (get performance
counter info) interface".

Makes the "not enabled" message less awful (and hidden unless
debugging).

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

fixup for "powerpc/perf: Add support for the hv 24x7 interface"

Makes the "not enabled" message less awful (and hides it in most cases).

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

The if condition check was based on a draft ISA doc. Remove the same.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

We have two copies of code that creates an OPAL sg list. Consolidate
these into a common set of helpers and fix the endian issues.

The flash interface embedded a version number in the num_entries
field, whereas the dump interface did did not. Since versioning
wasn't added to the flash interface and it is impossible to add
this in a backwards compatible way, just remove it.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Fix little endian issues with the OPAL error log code.

Signed-off-by: Anton Blanchard <anton@samba.org>
Reviewed-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

The bitmap in opal_poll_events and opal_handle_interrupt is
big endian, so we need to byteswap it on little endian builds.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

We had some duplication of the internal OPAL functions.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Using size_t in our APIs is asking for trouble, especially
when some OPAL calls use size_t pointers.

Signed-off-by: Anton Blanchard <anton@samba.org>
Reviewed-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

On PowerNV platform, we are holding an unnecessary refcount on a pci_dev, which
leads to the pci_dev is not destroyed when hotplugging a pci device.

This patch release the unnecessary refcount.

Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

During the EEH hotplug event, iommu_add_device() will be invoked three times
and two of them will trigger warning or error.

The three times to invoke the iommu_add_device() are:

    pci_device_add
       ...
       set_iommu_table_base_and_group   <- 1st time, fail
    device_add
       ...
       tce_iommu_bus_notifier           <- 2nd time, succees
    pcibios_add_pci_devices
       ...
       pcibios_setup_bus_devices        <- 3rd time, re-attach

The first time fails, since the dev->kobj->sd is not initialized. The
dev->kobj->sd is initialized in device_add().
The third time's warning is triggered by the re-attach of the iommu_group.

After applying this patch, the error

    iommu_tce: 0003:05:00.0 has not been added, ret=-14

and the warning

    [  204.123609] ------------[ cut here ]------------
    [  204.123645] WARNING: at arch/powerpc/kernel/iommu.c:1125
    [  204.123680] Modules linked in: xt_CHECKSUM nf_conntrack_netbios_ns nf_conntrack_broadcast ipt_MASQUERADE ip6t_REJECT bnep bluetooth 6lowpan_iphc rfkill xt_conntrack ebtable_nat ebtable_broute bridge stp llc mlx4_ib ib_sa ib_mad ib_core ib_addr ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw bnx2x tg3 mlx4_core nfsd ptp mdio ses libcrc32c nfs_acl enclosure be2net pps_core shpchp lockd kvm uinput sunrpc binfmt_misc lpfc scsi_transport_fc ipr scsi_tgt
    [  204.124356] CPU: 18 PID: 650 Comm: eehd Not tainted 3.14.0-rc5yw+ #102
    [  204.124400] task: c0000027ed485670 ti: c0000027ed50c000 task.ti: c0000027ed50c000
    [  204.124453] NIP: c00000000003cf80 LR: c00000000006c648 CTR: c00000000006c5c0
    [  204.124506] REGS: c0000027ed50f440 TRAP: 0700   Not tainted  (3.14.0-rc5yw+)
    [  204.124558] MSR: 9000000000029032 <SF,HV,EE,ME,IR,DR,RI>  CR: 88008084  XER: 20000000
    [  204.124682] CFAR: c00000000006c644 SOFTE: 1
    GPR00: c00000000006c648 c0000027ed50f6c0 c000000001398380 c0000027ec260300
    GPR04: c0000027ea92c000 c00000000006ad00 c0000000016e41b0 0000000000000110
    GPR08: c0000000012cd4c0 0000000000000001 c0000027ec2602ff 0000000000000062
    GPR12: 0000000028008084 c00000000fdca200 c0000000000d1d90 c0000027ec281a80
    GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
    GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000001
    GPR24: 000000005342697b 0000000000002906 c000001fe6ac9800 c000001fe6ac9800
    GPR28: 0000000000000000 c0000000016e3a80 c0000027ea92c090 c0000027ea92c000
    [  204.125353] NIP [c00000000003cf80] .iommu_add_device+0x30/0x1f0
    [  204.125399] LR [c00000000006c648] .pnv_pci_ioda_dma_dev_setup+0x88/0xb0
    [  204.125443] Call Trace:
    [  204.125464] [c0000027ed50f6c0] [c0000027ed50f750] 0xc0000027ed50f750 (unreliable)
    [  204.125526] [c0000027ed50f750] [c00000000006c648] .pnv_pci_ioda_dma_dev_setup+0x88/0xb0
    [  204.125588] [c0000027ed50f7d0] [c000000000069cc8] .pnv_pci_dma_dev_setup+0x78/0x340
    [  204.125650] [c0000027ed50f870] [c000000000044408] .pcibios_setup_device+0x88/0x2f0
    [  204.125712] [c0000027ed50f940] [c000000000046040] .pcibios_setup_bus_devices+0x60/0xd0
    [  204.125774] [c0000027ed50f9c0] [c000000000043acc] .pcibios_add_pci_devices+0xdc/0x1c0
    [  204.125837] [c0000027ed50fa50] [c00000000086f970] .eeh_reset_device+0x36c/0x4f0
    [  204.125939] [c0000027ed50fb20] [c00000000003a2d8] .eeh_handle_normal_event+0x448/0x480
    [  204.126068] [c0000027ed50fbc0] [c00000000003a35c] .eeh_handle_event+0x4c/0x340
    [  204.126192] [c0000027ed50fc80] [c00000000003a74c] .eeh_event_handler+0xfc/0x1b0
    [  204.126319] [c0000027ed50fd30] [c0000000000d1ea0] .kthread+0x110/0x130
    [  204.126430] [c0000027ed50fe30] [c00000000000a460] .ret_from_kernel_thread+0x5c/0x7c
    [  204.126556] Instruction dump:
    [  204.126610] 7c0802a6 fba1ffe8 fbc1fff0 fbe1fff8 f8010010 f821ff71 7c7e1b78 60000000
    [  204.126787] 60000000 e87e0298 3143ffff 7d2a1910 <0b090000> 2fa90000 40de00c8 ebfe0218
    [  204.126966] ---[ end trace 6e7aefd80add2973 ]---

are cleared.

This patch removes iommu_add_device() in pnv_pci_ioda_dma_dev_setup(), which
revert part of the change in commit d905c5df(PPC: POWERNV: move
iommu_add_device earlier).

Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

With this patch I was able to update firmware on an LE kernel.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

We have a subtle race when sending CPUs back to OPAL on kexec.

We mark them as "in real mode" right before we send them down. Once
we've booted the new kernel, it might try to call opal_reinit_cpus()
to change endianness, and that requires all CPUs to be spinning inside
OPAL.

However there is no synchronization here and we've observed cases
where the returning CPUs hadn't established their new state inside
OPAL before opal_reinit_cpus() is called, causing it to fail.

The proper fix is to actually wait for them to go down all the way
from the kexec'ing kernel.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

The size of the sysparam sysfs files is determined from the device tree
at boot. However the buffer is hard coded to 64 bytes. If we encounter a
parameter that is larger than 64, or miss-parse the device tree, the
buffer will overflow when reading or writing to the parameter.

Check it at discovery time, and if the parameter is too large, do not
create a sysfs entry for it.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>