Very large kernels may require linker stubs for branches from HEAD
text code. The linker may place these stubs before the HEAD text
sections, which breaks the assumption that HEAD text is located at 0
(or the .text section being located at 0x7000/0x8000 on Book3S
kernels).

Provide an option to create a small section just before the .text
section with an empty 256 - 4 bytes, and adjust the start of the .text
section to match. The linker will tend to put stubs in that section
and not break our relative-to-absolute offset assumptions.

This causes a small waste of space on common kernels, but allows large
kernels to build and boot. For now, it is an EXPERT config option,
defaulting to =n, but a reference is provided for it in the build-time
check for such breakage. This is good enough for allyesconfig and
custom users / hackers.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Direct banches from code below __end_interrupts to code above
__end_interrupts when built with CONFIG_RELOCATABLE are disallowed
because they will break when the kernel is not located at 0.

Sample output:

    WARNING: Unrelocated relative branches
    c000000000000118 bl-> 0xc000000000038fb8 <pnv_restore_hyp_resource>
    c00000000000013c b-> 0xc0000000001068a4 <kvm_start_guest>
    c000000000000148 b-> 0xc00000000003919c <pnv_wakeup_loss>
    c00000000000014c b-> 0xc00000000003923c <pnv_wakeup_noloss>
    c0000000000005a4 b-> 0xc000000000106ffc <kvmppc_interrupt_hv>
    c000000000001af0 b-> 0xc000000000106ffc <kvmppc_interrupt_hv>
    c000000000001b24 b-> 0xc000000000106ffc <kvmppc_interrupt_hv>
    c000000000001b58 b-> 0xc000000000106ffc <kvmppc_interrupt_hv>
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

For final link, the powerpc64 linker generates fpr save/restore
functions on-demand, placing them in the .sfpr section. Starting with
binutils 2.25, these can be provided for non-final links with
--save-restore-funcs. Use that where possible for module links.

This saves about 200 bytes per module (~60kB) on powernv defconfig
build.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

There is no need to create a new section for these. Consolidate with
32-bit and just use .text.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

crtsaveres.S is empty with 64-bit builds already, so just don't
build and link it to match the vmlinux build.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Use CONFIG_PPC64_BOOT_WRAPPER not CONFIG_PPC32 to fix BE build]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The 64-bit linker creates save/restore functions on demand with final
links, so vmlinux does not require crtsavres.o.

Make crtsavres.o extra-y on 64-bit (it is still required by modules).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The arch version is identical except for comments and white space.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

These are completely obvious as all they do is include the asm-generic
versions.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Prevent a kernel panic caused by unintentionally clearing TCR watchdog
bits. At this point in the kernel boot, the watchdog may have already
been enabled by u-boot. The original code's attempt to write to the TCR
register results in an inadvertent clearing of the watchdog
configuration bits, causing the 476 to reset.
Signed-off-by: Ivan Mikhaylov <ivan@de.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

This patch adds default FSP2 config for main usage.
Signed-off-by: Ivan Mikhaylov <ivan@de.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Add a device tree for FSP2 board (476 based).
Signed-off-by: Ivan Mikhaylov <ivan@de.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Add platform code support for FSP2 (476fpe) board.
Signed-off-by: Ivan Mikhaylov <ivan@de.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The current code in the cpuidle-powernv intialization only allows deep
stop states (indicated by OPAL_PM_STOP_INST_DEEP) which lose timebase
(indicated by OPAL_PM_TIMEBASE_STOP). This assumption goes back to
POWER8 time where deep states used to lose the timebase. However, on
POWER9, we do have stop states that are deep (they lose hypervisor
state) but retain the timebase.

Fix the initialization code in the cpuidle-powernv driver to allow
such deep states.

Further, there is a bug in cpuidle-powernv driver with
CONFIG_TICK_ONESHOT=n where we end up incrementing the nr_idle_states
even if a platform idle state which loses time base was not added to
the cpuidle table.

Fix this by ensuring that the nr_idle_states variable gets incremented
only when the platform idle state was added to the cpuidle table.
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

On Power9 DD1 due to a hardware bug the Power-Saving Level Status
field (PLS) of the PSSCR for a thread waking up from a deep state can
under-report if some other thread in the core is in a shallow stop
state. The scenario in which this can manifest is as follows:

   1) All the threads of the core are in deep stop.
   2) One of the threads is woken up. The PLS for this thread will
      correctly reflect that it is waking up from deep stop.
   3) The thread that has woken up now executes a shallow stop.
   4) When some other thread in the core is woken, its PLS will reflect
      the shallow stop state.

Thus, the subsequent thread for which the PLS is under-reporting the
wakeup state will not restore the hypervisor resources.

Hence, on DD1 systems, use the Requested Level (RL) field as a
workaround to restore the contents of the hypervisor resources on the
wakeup from the stop state.
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Some of the SPR values (HID0, MSR, SPRG0) don't change during the run
time of a booted kernel, once they have been initialized.

The contents of these SPRs are lost when the CPUs enter deep stop
states. So instead saving and restoring SPRs from the kernel, use the
stop-api provided by the firmware by which the firmware can restore
the contents of these SPRs to their initialized values after wakeup
from a deep stop state.

Apart from these, program the PSSCR value to that of the deepest stop
state via the stop-api. This will be used to indicate to the
underlying firmware as to what stop state to put the threads that have
been woken up by a special-wakeup.

And while we are at programming SPRs via stop-api, ensure that HID1,
HID4 and HID5 registers which are only available on POWER8 are not
requested to be restored by the firware on POWER9.
Signed-off-by: Akshay Adiga <akshay.adiga@linux.vnet.ibm.com>
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

On wakeup from a deep stop state which is supposed to lose the
hypervisor state, we don't restore the LPCR to the old value but set
it to a "sane" value via cur_cpu_spec->cpu_restore().

The problem is that the "sane" value doesn't include UPRT and the HR
bits which are required to run correctly in Radix mode.

Fix this on POWER9 onwards by restoring the LPCR value whatever it was
before executing the stop instruction.
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

On POWER8, in case of
   -  nap: both timebase and hypervisor state is retained.
   -  fast-sleep: timebase is lost. But the hypervisor state is retained.
   -  winkle: timebase and hypervisor state is lost.

Hence, the current code for handling exit from a idle state assumes
that if the timebase value is retained, then so is the hypervisor
state. Thus, the current code doesn't restore per-core hypervisor
state in such cases.

But that is no longer the case on POWER9 where we do have stop states
in which timebase value is retained, but the hypervisor state is
lost. So we have to ensure that the per-core hypervisor state gets
restored in such cases.

Fix this by ensuring that even in the case when timebase is retained,
we explicitly check if we are waking up from a deep stop that loses
per-core hypervisor state (indicated by cr4 being eq or gt), and if
this is the case, we restore the per-core hypervisor state.
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The lower 8 bits of core_idle_state_ptr tracks the number of non-idle
threads in the core. This is supposed to be initialized to bit-map
corresponding to the threads_per_core. However, currently it is
initialized to PNV_CORE_IDLE_THREAD_BITS (0xFF). This is correct for
POWER8 which has 8 threads per core, but not for POWER9 which has 4
threads per core.

As a result, on POWER9, core_idle_state_ptr gets initialized to
0xFF. In case when all the threads of the core are idle, the bits
corresponding tracking the idle-threads are non-zero. As a result, the
idle entry/exit code fails to save/restore per-core hypervisor state
since it assumes that there are threads in the cores which are still
active.

Fix this by correctly initializing the lower bits of the
core_idle_state_ptr on the basis of threads_per_core.
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Allow us to enable IRQ_TIME_ACCOUNTING. Even though we currently
use VIRT_CPU_ACCOUNTING_NATIVE, that option is quite heavy
weight and IRQ_TIME_ACCOUNTING might be better in some cases.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Currently the DTS defines two partitions at the same addresses, if you
use one, you will corrupt information on the other one. Fix it by
shifting the second partition.
Signed-off-by: Pavel Machek <pavel@denx.de>
[mpe: Reconstruct change log from email thread]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Experiments with the netperf benchmark indicated that the size selecting
VMX-based copies in __copy_tofrom_user_power7() was suboptimal on POWER8.
Measurements showed that parity was in the neighbourhood of 3328 bytes,
rather than greater than 4096. The change gives a 1.5-2.0% improvement in
performance for 4096-byte buffers, reducing the relative time spent in
__copy_tofrom_user_power7() from approximately 7% to approximately 5% in
the TCP_RR benchmark.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Acked-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Rearrange the code so that mode and badaddr are only defined when
they're used.

Also unsplit the string for easier grepping, and switch from CONFIG_8xx
which is deprecated to CONFIG_PPC_8xx.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Fixes: a7cd88da ("powerpc/powernv: Move CPU-Offline idle state invocation from smp.c to idle.c")
Cc: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

OPAL_CALL uses SRR[01] with MSR_RI=1, which gets corrupted if there
is an interleaving system reset or machine check interrupt.

Use HSRR[01] instead, which does not require MSR_RI=0.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

FIXUP_ENDIAN uses SRR[01] with MSR_RI=1, which gets corrupted if there
is an interleaving system reset or machine check interrupt.

Set MSR_RI=0 before setting SRRs. The rfid will restore MSR.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Pull thermal SoC management fixes from Eduardo Valentin:

 - fixes to TI SoC driver, Broadcom, qoriq

 - small sparse warning fix on thermal core

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal:
  thermal: broadcom: ns-thermal: default on iProc SoCs
  ti-soc-thermal: Fix a typo in a comment line
  ti-soc-thermal: Delete error messages for failed memory allocations in ti_bandgap_build()
  ti-soc-thermal: Use devm_kcalloc() in ti_bandgap_build()
  thermal: core: make thermal_emergency_poweroff static
  thermal: qoriq: remove useless call for of_thermal_get_trip_points()

Pull tty/serial fixes from Greg KH:
 "Here are some serial and tty fixes for 4.12-rc3. They are a bit bigger
  than normal, which is why I had them bake in linux-next for a few
  weeks and didn't send them to you for -rc2.

  They revert a few of the serdev patches from 4.12-rc1, and bring
  things back to how they were in 4.11, to try to make things a bit more
  stable there. Rob and Johan both agree that this is the way forward,
  so this isn't people squabbling over semantics. Other than that, just
  a few minor serial driver fixes that people have had problems with.

  All of these have been in linux-next for a few weeks with no reported
  issues"

* tag 'tty-4.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: altera_uart: call iounmap() at driver remove
  serial: imx: ensure UCR3 and UFCR are setup correctly
  MAINTAINERS/serial: Change maintainer of jsm driver
  serial: enable serdev support
  tty/serdev: add serdev registration interface
  serdev: Restore serdev_device_write_buf for atomic context
  serial: core: fix crash in uart_suspend_port
  tty: fix port buffer locking
  tty: ehv_bytechan: clean up init error handling
  serial: ifx6x60: fix use-after-free on module unload
  serial: altera_jtaguart: adding iounmap()
  serial: exar: Fix stuck MSIs
  serial: efm32: Fix parity management in 'efm32_uart_console_get_options()'
  serdev: fix tty-port client deregistration
  Revert "tty_port: register tty ports with serdev bus"
  drivers/tty: 8250: only call fintek_8250_probe when doing port I/O

Pull powerpc fixes from Michael Ellerman:
 "Fix running SPU programs on Cell, and a few other minor fixes.

  Thanks to Alistair Popple, Jeremy Kerr, Michael Neuling, Nicholas
  Piggin"

* tag 'powerpc-4.12-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc: Add PPC_FEATURE userspace bits for SCV and DARN instructions
  powerpc/spufs: Fix hash faults for kernel regions
  powerpc: Fix booting P9 hash with CONFIG_PPC_RADIX_MMU=N
  powerpc/powernv/npu-dma.c: Fix opal_npu_destroy_context() call
  selftests/powerpc: Fix TM resched DSCR test with some compilers

Pull x86 fixes from Thomas Gleixner:
 "A series of fixes for X86:

   - The final fix for the end-of-stack issue in the unwinder
   - Handle non PAT systems gracefully
   - Prevent access to uninitiliazed memory
   - Move early delay calaibration after basic init
   - Fix Kconfig help text
   - Fix a cross compile issue
   - Unbreak older make versions"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/timers: Move simple_udelay_calibration past init_hypervisor_platform
  x86/alternatives: Prevent uninitialized stack byte read in apply_alternatives()
  x86/PAT: Fix Xorg regression on CPUs that don't support PAT
  x86/watchdog: Fix Kconfig help text file path reference to lockup watchdog documentation
  x86/build: Permit building with old make versions
  x86/unwind: Add end-of-stack check for ftrace handlers
  Revert "x86/entry: Fix the end of the stack for newly forked tasks"
  x86/boot: Use CROSS_COMPILE prefix for readelf

Pull timer fixlet from Thomas Gleixner:
 "Silence dmesg spam by making the posix cpu timer printks depend on
  print_fatal_signals"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  posix-timers: Make signal printks conditional

Pull RAS fixes from Thomas Gleixner:
 "Two fixlets for RAS:

   - Export memory_error() so the NFIT module can utilize it

   - Handle memory errors in NFIT correctly"

* 'ras-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  acpi, nfit: Fix the memory error check in nfit_handle_mce()
  x86/MCE: Export memory_error()

Pull perf tooling fixes from Thomas Gleixner:

 - Synchronization of tools and kernel headers

 - A series of fixes for perf report addressing various failures:
    * Handle invalid maps proper
    * Plug a memory leak
    * Handle frames and callchain order correctly

 - Fixes for handling inlines and children mode

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tools/include: Sync kernel ABI headers with tooling headers
  perf tools: Put caller above callee in --children mode
  perf report: Do not drop last inlined frame
  perf report: Always honor callchain order for inlined nodes
  perf script: Add --inline option for debugging
  perf report: Fix off-by-one for non-activation frames
  perf report: Fix memory leak in addr2line when called by addr2inlines
  perf report: Don't crash on invalid maps in `-g srcline` mode

Pull locking fix from Thomas Gleixner:
 "A fix for a state leak which was introduced in the recent rework of
  futex/rtmutex interaction"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex,rt_mutex: Fix rt_mutex_cleanup_proxy_lock()

Pull kthread fix from Thomas Gleixner:
 "A single fix which prevents a use after free when kthread fork fails"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  kthread: Fix use-after-free if kthread fork fails

Pull ftrace fixes from Steven Rostedt:
 "There's been a few memory issues found with ftrace.

  One was simply a memory leak where not all was being freed that should
  have been in releasing a file pointer on set_graph_function.

  Then Thomas found that the ftrace trampolines were marked for
  read/write as well as execute. To shrink the possible attack surface,
  he added calls to set them to ro. Which also uncovered some other
  issues with freeing module allocated memory that had its permissions
  changed.

  Kprobes had a similar issue which is fixed and a selftest was added to
  trigger that issue again"

* tag 'trace-v4.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  x86/ftrace: Make sure that ftrace trampolines are not RWX
  x86/mm/ftrace: Do not bug in early boot on irqs_disabled in cpu_flush_range()
  selftests/ftrace: Add a testcase for many kprobe events
  kprobes/x86: Fix to set RWX bits correctly before releasing trampoline
  ftrace: Fix memory leak in ftrace_graph_release()

ftrace use module_alloc() to allocate trampoline pages. The mapping of
module_alloc() is RWX, which makes sense as the memory is written to right
after allocation. But nothing makes these pages RO after writing to them.

Add proper set_memory_rw/ro() calls to protect the trampolines after
modification.

Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1705251056410.1862@nanosSigned-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

With function tracing starting in early bootup and having its trampoline
pages being read only, a bug triggered with the following:

kernel BUG at arch/x86/mm/pageattr.c:189!
invalid opcode: 0000 [#1] SMP
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 4.12.0-rc2-test+ #3
Hardware name: MSI MS-7823/CSM-H87M-G43 (MS-7823), BIOS V1.6 02/22/2014
task: ffffffffb4222500 task.stack: ffffffffb4200000
RIP: 0010:change_page_attr_set_clr+0x269/0x302
RSP: 0000:ffffffffb4203c88 EFLAGS: 00010046
RAX: 0000000000000046 RBX: 0000000000000000 RCX: 00000001b6000000
RDX: ffffffffb4203d40 RSI: 0000000000000000 RDI: ffffffffb4240d60
RBP: ffffffffb4203d18 R08: 00000001b6000000 R09: 0000000000000001
R10: ffffffffb4203aa8 R11: 0000000000000003 R12: ffffffffc029b000
R13: ffffffffb4203d40 R14: 0000000000000001 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff9a639ea00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff9a636b384000 CR3: 00000001ea21d000 CR4: 00000000000406b0
Call Trace:
 change_page_attr_clear+0x1f/0x21
 set_memory_ro+0x1e/0x20
 arch_ftrace_update_trampoline+0x207/0x21c
 ? ftrace_caller+0x64/0x64
 ? 0xffffffffc029b000
 ftrace_startup+0xf4/0x198
 register_ftrace_function+0x26/0x3c
 function_trace_init+0x5e/0x73
 tracer_init+0x1e/0x23
 tracing_set_tracer+0x127/0x15a
 register_tracer+0x19b/0x1bc
 init_function_trace+0x90/0x92
 early_trace_init+0x236/0x2b3
 start_kernel+0x200/0x3f5
 x86_64_start_reservations+0x29/0x2b
 x86_64_start_kernel+0x17c/0x18f
 secondary_startup_64+0x9f/0x9f
 ? secondary_startup_64+0x9f/0x9f

Interrupts should not be enabled at this early in the boot process. It is
also fine to leave interrupts enabled during this time as there's only one
CPU running, and on_each_cpu() means to only run on the current CPU.

If early_boot_irqs_disabled is set, it is safe to run cpu_flush_range() with
interrupts disabled. Don't trigger a BUG_ON() in that case.

Link: http://lkml.kernel.org/r/20170526093717.0be3b849@gandalf.local.homeSuggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Add a testcase to test kprobes via ftrace interface
with many concurrent kprobe events.

This tries to add many kprobe events (up to 256) on
kernel functions. To avoid making ftrace-based
kprobes (kprobes on fentry), it skips first N bytes
(on x86 N=5, on ppc or arm N=4) of function entry.
After that, it enables all those events, disable it,
and remove it.

Since the unoptimization buffer reclaiming will
be delayed, after removing events, it will wait
enough time.

Link: http://lkml.kernel.org/r/149577388470.11702.11832460851769204511.stgit@devboxSigned-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>