The shared (magic) page is a data structure that contains often used
supervisor privileged SPRs accessible via memory to the user to reduce
the number of exits we have to take to read/write them.

When we actually share this structure with the guest we have to maintain
it in guest endianness, because some of the patch tricks only work with
native endian load/store operations.

Since we only share the structure with either host or guest in little
endian on book3s_64 pr mode, we don't have to worry about booke or book3s hv.

For booke, the shared struct stays big endian. For book3s_64 hv we maintain
the struct in host native endian, since it never gets shared with the guest.

For book3s_64 pr we introduce a variable that tells us which endianness the
shared struct is in and route every access to it through helper inline
functions that evaluate this variable.
Signed-off-by: NAlexander Graf <agraf@suse.de>

We expose a blob of hypercall instructions to user space that it gives to
the guest via device tree again. That blob should contain a stream of
instructions necessary to do a hypercall in big endian, as it just gets
passed into the guest and old guests use them straight away.
Signed-off-by: NAlexander Graf <agraf@suse.de>

When the guest does an RTAS hypercall it keeps all RTAS variables inside a
big endian data structure.

To make sure we don't have to bother about endianness inside the actual RTAS
handlers, let's just convert the whole structure to host endian before we
call our RTAS handlers and back to big endian when we return to the guest.
Signed-off-by: NAlexander Graf <agraf@suse.de>

The HTAB on PPC is always in big endian. When we access it via hypercalls
on behalf of the guest and we're running on a little endian host, we need
to make sure we swap the bits accordingly.
Signed-off-by: NAlexander Graf <agraf@suse.de>

The default MSR when user space does not define anything should be identical
on little and big endian hosts, so remove MSR_LE from it.
Signed-off-by: NAlexander Graf <agraf@suse.de>

The "shadow SLB" in the PACA is shared with the hypervisor, so it has to
be big endian. We access the shadow SLB during world switch, so let's make
sure we access it in big endian even when we're on a little endian host.
Signed-off-by: NAlexander Graf <agraf@suse.de>

The HTAB is always big endian. We access the guest's HTAB using
copy_from/to_user, but don't yet take care of the fact that we might
be running on an LE host.

Wrap all accesses to the guest HTAB with big endian accessors.
Signed-off-by: NAlexander Graf <agraf@suse.de>

The HTAB is always big endian. We access the guest's HTAB using
copy_from/to_user, but don't yet take care of the fact that we might
be running on an LE host.

Wrap all accesses to the guest HTAB with big endian accessors.
Signed-off-by: NAlexander Graf <agraf@suse.de>

Commit 9308ab8e made C/R HTAB updates go byte-wise into the target HTAB.
However, it didn't update the guest's copy of the HTAB, but instead the
host local copy of it.

Write to the guest's HTAB instead.
Signed-off-by: NAlexander Graf <agraf@suse.de>
CC: Paul Mackerras <paulus@samba.org>
Acked-by: NPaul Mackerras <paulus@samba.org>

With debug option "sleep inside atomic section checking" enabled we get
the below WARN_ON during a PR KVM boot. This is because upstream now
have PREEMPT_COUNT enabled even if we have preempt disabled. Fix the
warning by adding preempt_disable/enable around floating point and altivec
enable.

WARNING: at arch/powerpc/kernel/process.c:156
Modules linked in: kvm_pr kvm
CPU: 1 PID: 3990 Comm: qemu-system-ppc Tainted: G        W     3.15.0-rc1+ #4
task: c0000000eb85b3a0 ti: c0000000ec59c000 task.ti: c0000000ec59c000
NIP: c000000000015c84 LR: d000000003334644 CTR: c000000000015c00
REGS: c0000000ec59f140 TRAP: 0700   Tainted: G        W      (3.15.0-rc1+)
MSR: 8000000000029032 <SF,EE,ME,IR,DR,RI>  CR: 42000024  XER: 20000000
CFAR: c000000000015c24 SOFTE: 1
GPR00: d000000003334644 c0000000ec59f3c0 c000000000e2fa40 c0000000e2f80000
GPR04: 0000000000000800 0000000000002000 0000000000000001 8000000000000000
GPR08: 0000000000000001 0000000000000001 0000000000002000 c000000000015c00
GPR12: d00000000333da18 c00000000fb80900 0000000000000000 0000000000000000
GPR16: 0000000000000000 0000000000000000 0000000000000000 00003fffce4e0fa1
GPR20: 0000000000000010 0000000000000001 0000000000000002 00000000100b9a38
GPR24: 0000000000000002 0000000000000000 0000000000000000 0000000000000013
GPR28: 0000000000000000 c0000000eb85b3a0 0000000000002000 c0000000e2f80000
NIP [c000000000015c84] .enable_kernel_fp+0x84/0x90
LR [d000000003334644] .kvmppc_handle_ext+0x134/0x190 [kvm_pr]
Call Trace:
[c0000000ec59f3c0] [0000000000000010] 0x10 (unreliable)
[c0000000ec59f430] [d000000003334644] .kvmppc_handle_ext+0x134/0x190 [kvm_pr]
[c0000000ec59f4c0] [d00000000324b380] .kvmppc_set_msr+0x30/0x50 [kvm]
[c0000000ec59f530] [d000000003337cac] .kvmppc_core_emulate_op_pr+0x16c/0x5e0 [kvm_pr]
[c0000000ec59f5f0] [d00000000324a944] .kvmppc_emulate_instruction+0x284/0xa80 [kvm]
[c0000000ec59f6c0] [d000000003336888] .kvmppc_handle_exit_pr+0x488/0xb70 [kvm_pr]
[c0000000ec59f790] [d000000003338d34] kvm_start_lightweight+0xcc/0xdc [kvm_pr]
[c0000000ec59f960] [d000000003336288] .kvmppc_vcpu_run_pr+0xc8/0x190 [kvm_pr]
[c0000000ec59f9f0] [d00000000324c880] .kvmppc_vcpu_run+0x30/0x50 [kvm]
[c0000000ec59fa60] [d000000003249e74] .kvm_arch_vcpu_ioctl_run+0x54/0x1b0 [kvm]
[c0000000ec59faf0] [d000000003244948] .kvm_vcpu_ioctl+0x478/0x760 [kvm]
[c0000000ec59fcb0] [c000000000224e34] .do_vfs_ioctl+0x4d4/0x790
[c0000000ec59fd90] [c000000000225148] .SyS_ioctl+0x58/0xb0
[c0000000ec59fe30] [c00000000000a1e4] syscall_exit+0x0/0x98
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

This patch make sure we inherit the LE bit correctly in different case
so that we can run Little Endian distro in PR mode
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

The dcbtls instruction is able to lock data inside the L1 cache.

We don't want to give the guest actual access to hardware cache locks,
as that could influence other VMs on the same system. But we can tell
the guest that its locking attempt failed.

By implementing the instruction we at least don't give the guest a
program exception which it definitely does not expect.
Signed-off-by: NAlexander Graf <agraf@suse.de>

The L1 instruction cache control register contains bits that indicate
that we're still handling a request. Mask those out when we set the SPR
so that a read doesn't assume we're still doing something.
Signed-off-by: NAlexander Graf <agraf@suse.de>

Commit 8f619b54 ("powerpc/ppc64: Do not turn AIL (reloc-on
interrupts) too early") added code to set the AIL bit in the LPCR
without checking whether the kernel is running in hypervisor mode.  The
result is that when the kernel is running as a guest (i.e., under
PowerKVM or PowerVM), the processor takes a privileged instruction
interrupt at that point, causing a panic.  The visible result is that
the kernel hangs after printing "returning from prom_init".

This fixes it by checking for hypervisor mode being available before
setting LPCR.  If we are not in hypervisor mode, we enable relocation-on
interrupts later in pSeries_setup_arch using the H_SET_MODE hcall.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We are currently using sysfs_schedule_callback() which is deprecated
and about to be removed. Switch to the new interface instead.
Signed-off-by: NStewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Since v1:
	Edited the comment according to Srivatsa's suggestion.

During the testing, we encounter below WARN followed by Oops:

	WARNING: at kernel/sched/core.c:6218
	...
	NIP [c000000000101660] .build_sched_domains+0x11d0/0x1200
	LR [c000000000101358] .build_sched_domains+0xec8/0x1200
	PACATMSCRATCH [800000000000f032]
	Call Trace:
	[c00000001b103850] [c000000000101358] .build_sched_domains+0xec8/0x1200
	[c00000001b1039a0] [c00000000010aad4] .partition_sched_domains+0x484/0x510
	[c00000001b103aa0] [c00000000016d0a8] .rebuild_sched_domains+0x68/0xa0
	[c00000001b103b30] [c00000000005cbf0] .topology_work_fn+0x10/0x30
	...
	Oops: Kernel access of bad area, sig: 11 [#1]
	...
	NIP [c00000000045c000] .__bitmap_weight+0x60/0xf0
	LR [c00000000010132c] .build_sched_domains+0xe9c/0x1200
	PACATMSCRATCH [8000000000029032]
	Call Trace:
	[c00000001b1037a0] [c000000000288ff4] .kmem_cache_alloc_node_trace+0x184/0x3a0
	[c00000001b103850] [c00000000010132c] .build_sched_domains+0xe9c/0x1200
	[c00000001b1039a0] [c00000000010aad4] .partition_sched_domains+0x484/0x510
	[c00000001b103aa0] [c00000000016d0a8] .rebuild_sched_domains+0x68/0xa0
	[c00000001b103b30] [c00000000005cbf0] .topology_work_fn+0x10/0x30
	...

This was caused by that 'sd->groups == NULL' after building groups, which
was caused by the empty 'sd->span'.

The cpu's domain contained nothing because the cpu was assigned to a wrong
node, due to the following unfortunate sequence of events:

1. The hypervisor sent a topology update to the guest OS, to notify changes
   to the cpu-node mapping. However, the update was actually redundant - i.e.,
   the "new" mapping was exactly the same as the old one.

2. Due to this, the 'updated_cpus' mask turned out to be empty after exiting
   the 'for-loop' in arch_update_cpu_topology().

3. So we ended up calling stop-machine() with an empty cpumask list, which made
   stop-machine internally elect cpumask_first(cpu_online_mask), i.e., CPU0 as
   the cpu to run the payload (the update_cpu_topology() function).

4. This causes update_cpu_topology() to be run by CPU0. And since 'updates'
   is kzalloc()'ed inside arch_update_cpu_topology(), update_cpu_topology()
   finds update->cpu as well as update->new_nid to be 0. In other words, we
   end up assigning CPU0 (and eventually its siblings) to node 0, incorrectly.

Along with the following wrong updating, it causes the sched-domain rebuild
code to break and crash the system.

Fix this by skipping the topology update in cases where we find that
the topology has not actually changed in reality (ie., spurious updates).

CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Paul Mackerras <paulus@samba.org>
CC: Nathan Fontenot <nfont@linux.vnet.ibm.com>
CC: Stephen Rothwell <sfr@canb.auug.org.au>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Robert Jennings <rcj@linux.vnet.ibm.com>
CC: Jesse Larrew <jlarrew@linux.vnet.ibm.com>
CC: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
CC: Alistair Popple <alistair@popple.id.au>
Suggested-by: N"Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: NMichael Wang <wangyun@linux.vnet.ibm.com>
Reviewed-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

When building modules with a native le toolchain the linker will
generate R_PPC64_TOCSAVE relocations when it's safe to omit saving r2 on
a plt call.  This isn't helpful in the conext of a kernel module and the
kernel will fail to load those modules with an error like:
	nf_conntrack: Unknown ADD relocation: 109

This patch tells the linker to avoid createing R_PPC64_TOCSAVE
relocations allowing modules to load.
Signed-off-by: NTony Breeds <tony@bakeyournoodle.com>
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Here rcu_assign_pointer() is ensuring that the
initialization of a structure is carried out before storing a pointer
to that structure.
So, rcu_assign_pointer(p, NULL) can always safely be converted to
RCU_INIT_POINTER(p, NULL).
Signed-off-by: NMonam Agarwal <monamagarwal123@gmail.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

next-20140324 currently fails compiling celleb_defconfig with:

arch/powerpc/include/asm/opal.h:894:42: error: 'struct notifier_block' declared inside parameter list [-Werror]
arch/powerpc/include/asm/opal.h:894:42: error: its scope is only this definition or declaration, which is probably not what you want [-Werror]
arch/powerpc/include/asm/opal.h:896:14: error: 'struct notifier_block' declared inside parameter list [-Werror]

This is due to a missing include which is added here.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Just about all of these have been converted to __func__,
so convert the last uses.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Recent CPUs support quad word load and store instructions. Add
support to the alignment handler for them.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This call will not be understood by OPAL, and cause it to add an error
to it's log. Among other things, this is useful for testing the
behaviour of the log as it fills up.
Signed-off-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

OPAL provides an in-memory circular buffer containing a message log
populated with various runtime messages produced by the firmware.

Provide a sysfs interface /sys/firmware/opal/msglog for userspace to
view the messages.
Signed-off-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Currently we wrongly allocate mc_recoverable_range buffer (to hold
recoverable ranges) based on size of the property "mcheck-recoverable-ranges".
This results in allocating less memory to hold available recoverable range
entries from /proc/device-tree/ibm,opal/mcheck-recoverable-ranges.

This patch fixes this issue by allocating mc_recoverable_range buffer based
on number of entries of recoverable ranges instead of device property size.
Without this change we end up allocating less memory and run into memory
corruption issue.
Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

In:
  commit 742415d6
  Author: Michael Neuling <mikey@neuling.org>
  powerpc: Turn syscall handler into macros

We converted the syscall entry code onto macros, but in doing this we
introduced some cruft that's never run and should never have been added.

This removes that code.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This patch uses of_node_init() to initialize the kobject in the fake
node used in test_of_node(), to avoid following kobject warning.

[    0.897654] kobject: '(null)' (c0000007ca183a08): is not initialized, yet kobject_put() is being called.
[    0.897682] ------------[ cut here ]------------
[    0.897688] WARNING: at lib/kobject.c:670
[    0.897692] Modules linked in:
[    0.897701] CPU: 4 PID: 1 Comm: swapper/0 Not tainted 3.14.0+ #1
[    0.897708] task: c0000007ca100000 ti: c0000007ca180000 task.ti: c0000007ca180000
[    0.897715] NIP: c00000000046a1f0 LR: c00000000046a1ec CTR: 0000000001704660
[    0.897721] REGS: c0000007ca1835c0 TRAP: 0700   Not tainted  (3.14.0+)
[    0.897727] MSR: 8000000000029032 <SF,EE,ME,IR,DR,RI>  CR: 28000024  XER: 0000000d
[    0.897749] CFAR: c0000000008ef4ec SOFTE: 1
GPR00: c00000000046a1ec c0000007ca183840 c0000000014c59b8 000000000000005c
GPR04: 0000000000000001 c000000000129770 0000000000000000 0000000000000001
GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000003fef
GPR12: 0000000000000000 c00000000f221200 c00000000000c350 0000000000000000
GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR24: 0000000000000000 c00000000144e808 c000000000c56f20 00000000000000d8
GPR28: c000000000cd5058 0000000000000000 c000000001454ca8 c0000007ca183a08
[    0.897856] NIP [c00000000046a1f0] .kobject_put+0xa0/0xb0
[    0.897863] LR [c00000000046a1ec] .kobject_put+0x9c/0xb0
[    0.897868] Call Trace:
[    0.897874] [c0000007ca183840] [c00000000046a1ec] .kobject_put+0x9c/0xb0 (unreliable)
[    0.897885] [c0000007ca1838c0] [c000000000743f9c] .of_node_put+0x2c/0x50
[    0.897894] [c0000007ca183940] [c000000000c83954] .test_of_node+0x1dc/0x208
[    0.897902] [c0000007ca183b80] [c000000000c839a4] .msi_bitmap_selftest+0x24/0x38
[    0.897913] [c0000007ca183bf0] [c00000000000bb34] .do_one_initcall+0x144/0x200
[    0.897922] [c0000007ca183ce0] [c000000000c748e4] .kernel_init_freeable+0x2b4/0x394
[    0.897931] [c0000007ca183db0] [c00000000000c374] .kernel_init+0x24/0x130
[    0.897940] [c0000007ca183e30] [c00000000000a2f4] .ret_from_kernel_thread+0x5c/0x68
[    0.897947] Instruction dump:
[    0.897952] 7fe3fb78 38210080 e8010010 ebe1fff8 7c0803a6 4800014c e89f0000 3c62ff6e
[    0.897971] 7fe5fb78 3863a950 48485279 60000000 <0fe00000> 39000000 393f0038 4bffff80
[    0.897992] ---[ end trace 1eeffdb9f825a556 ]---
Signed-off-by: NLi Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We need to handle numa pte via the slow path
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

One OPAL call and one device tree property needed byte swapping.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Fix breakage which will be exposed by the patch "kconfig: make allnoconfig
disable options behind EMBEDDED and EXPERT".

arch/powerpc/kernel/mce.c, compiled in for PPC_BOOK3S_64, calls
functions only built when IRQ_WORK, so select it.  Fixes the following
build error:

  arch/powerpc/kernel/built-in.o: In function `.machine_check_queue_event':
  (.text+0x11260): undefined reference to `.irq_work_queue'
Signed-off-by: NJosh Triplett <josh@joshtriplett.org>
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch removes an artificial RapidIO bus root device and establishes
actual device hierarchy by providing reference to real parent devices.
It also introduces device class for RapidIO controller devices (on-chip
or an eternal bridge, known as "mport").

Existing implementation was sufficient for SoC-based platforms that have
a single RapidIO controller.  With introduction of devices using
multiple RapidIO controllers and PCIe-to-RapidIO bridges the old scheme
is very limiting or does not work at all.  The implemented changes allow
to properly reference platform's local RapidIO mport devices and provide
device details needed for upper layers.

This change to RapidIO device hierarchy does not break any known
existing kernel or user space interfaces.
Signed-off-by: NAlexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Andre van Herk <andre.van.herk@prodrive-technologies.com>
Cc: Stef van Os <stef.van.os@prodrive-technologies.com>
Cc: Jerry Jacobs <jerry.jacobs@prodrive-technologies.com>
Cc: Arno Tiemersma <arno.tiemersma@prodrive-technologies.com>
Cc: Rob Landley <rob@landley.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Eliminate the following warning in proc/vmcore.c:

  fs/proc/vmcore.c:1088:6: warning: no previous prototype for `vmcore_cleanup' [-Wmissing-prototypes]

[akpm@linux-foundation.org: clean up powerpc, remove unneeded EXPORT_SYMBOL]
Signed-off-by: NRashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
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>

Enable CPUFreq for PowerNV. Select "performance", "powersave",
"userspace" and "ondemand" governors. Choose "ondemand" to be the
default governor.
Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: NGautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Backend driver to dynamically set voltage and frequency on
IBM POWER non-virtualized platforms.  Power management SPRs
are used to set the required PState.

This driver works in conjunction with cpufreq governors
like 'ondemand' to provide a demand based frequency and
voltage setting on IBM POWER non-virtualized platforms.

PState table is obtained from OPAL v3 firmware through device
tree.

powernv_cpufreq back-end driver would parse the relevant device-tree
nodes and initialise the cpufreq subsystem on powernv platform.

The code was originally written by svaidy@linux.vnet.ibm.com. Over
time it was modified to accomodate bug-fixes as well as updates to the
the cpu-freq core. Relevant portions of the change logs corresponding
to those modifications are noted below:

 * The policy->cpus needs to be populated in a hotplug-invariant
   manner instead of using cpu_sibling_mask() which varies with
   cpu-hotplug. This is because the cpufreq core code copies this
   content into policy->related_cpus mask which should not vary on
   cpu-hotplug. [Authored by srivatsa.bhat@linux.vnet.ibm.com]

 * Create a helper routine that can return the cpu-frequency for the
   corresponding pstate_id. Also, cache the values of the pstate_max,
   pstate_min and pstate_nominal and nr_pstates in a static structure
   so that they can be reused in the future to perform any
   validations. [Authored by ego@linux.vnet.ibm.com]

 * Create a driver attribute named cpuinfo_nominal_freq which creates
   a sysfs read-only file named cpuinfo_nominal_freq. Export the
   frequency corresponding to the nominal_pstate through this
   interface.

     Nominal frequency is the highest non-turbo frequency for the
   platform.  This is generally used for setting governor policies
   from user space for optimal energy efficiency. [Authored by
   ego@linux.vnet.ibm.com]

 * Implement a powernv_cpufreq_get(unsigned int cpu) method which will
   return the current operating frequency. Export this via the sysfs
   interface cpuinfo_cur_freq by setting powernv_cpufreq_driver.get to
   powernv_cpufreq_get(). [Authored by ego@linux.vnet.ibm.com]

[Change log updated by ego@linux.vnet.ibm.com]
Reviewed-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: NVaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NGautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

OPAL defines opal_msg as a big endian struct so we have to
byte swap it on little endian builds.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

opal_notifier_register() is missing a pending "unregister" variant
and should be exposed to modules.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Turn them on at the same time as we allow MSR_IR/DR in the paca
kernel MSR, ie, after the MMU has been setup enough to be able
to handle relocated access to the linear mapping.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

If we take an interrupt such as a trap caused by a BUG_ON before the
MMU has been setup, the interrupt handlers try to enable virutal mode
and cause a recursive crash, making the original problem very hard
to debug.

This fixes it by adjusting the "kernel_msr" value in the PACA so that
it only has MSR_IR and MSR_DR (translation for instruction and data)
set after the MMU has been initialized for the processor.

We may still not have a console yet but at least we don't get into
a recursive fault (and early debug console or memory dump via JTAG
of the kernel buffer *will* give us the proper error).
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

All our cpu feature updates were done for every CPU in the device-tree,
thus overwriting the cputable bits over and over again. Instead do them
only for the boot CPU.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Move the definition to setup-common.c and set the init value
to -1 on both 32 and 64-bit (it was 0 on 64-bit).

Additionally add a check to prom.c to garantee that the init
value has been udpated after the DT scan.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

For historical reasons that code was under #ifdef CONFIG_PPC_PSERIES
but it applies equally to all 64-bit platforms.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>