It often happens to have simultaneous interrupts, for instance
when having double Ethernet attachment. With the current
implementation, we suffer the cost of kernel entry/exit for each
interrupt.

This patch introduces a loop in __do_irq() to handle all interrupts
at once before returning.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

IRQ 0 is a valid HW interrupt. So get_irq() shall return 0 when
there is no irq, instead of returning irq_linear_revmap(... ,0)

Fixes: f2a0bd37 ("[POWERPC] 8xx: powerpc port of core CPM PIC")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The 8xx has a dedicated exception for breakpoints, that directly
calls do_break()
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Analysis of the assembly code shows that when using user_mode(regs),
at least the 'andi.' is redone all the time, and also
the 'lwz ,132(r31)' most of the time. With the new form, the 'is_user'
is mapped to cr4, then all further use of is_user results in just
things like 'beq cr4,218 <do_page_fault+0x218>'

Without the patch:

  50:	81 1e 00 84 	lwz     r8,132(r30)
  54:	71 09 40 00 	andi.   r9,r8,16384
  58:	40 82 00 0c 	bne     64 <do_page_fault+0x64>

  84:	81 3e 00 84 	lwz     r9,132(r30)
  8c:	71 2a 40 00 	andi.   r10,r9,16384
  90:	41 a2 01 64 	beq     1f4 <do_page_fault+0x1f4>

  d4:	81 3e 00 84 	lwz     r9,132(r30)
  dc:	71 28 40 00 	andi.   r8,r9,16384
  e0:	41 82 02 08 	beq     2e8 <do_page_fault+0x2e8>

 108:	81 3e 00 84 	lwz     r9,132(r30)
 110:	71 28 40 00 	andi.   r8,r9,16384
 118:	41 82 02 28 	beq     340 <do_page_fault+0x340>

 1e4:	81 3e 00 84 	lwz     r9,132(r30)
 1e8:	71 2a 40 00 	andi.   r10,r9,16384
 1ec:	40 82 01 68 	bne     354 <do_page_fault+0x354>

 228:	81 3e 00 84 	lwz     r9,132(r30)
 22c:	71 28 40 00 	andi.   r8,r9,16384
 230:	41 82 ff c4 	beq     1f4 <do_page_fault+0x1f4>

 288:	71 2a 40 00 	andi.   r10,r9,16384
 294:	41 a2 fe 60 	beq     f4 <do_page_fault+0xf4>

 50c:	81 3e 00 84 	lwz     r9,132(r30)
 514:	71 2a 40 00 	andi.   r10,r9,16384
 518:	40 a2 fc e0 	bne     1f8 <do_page_fault+0x1f8>

 534:	81 3e 00 84 	lwz     r9,132(r30)
 53c:	71 2a 40 00 	andi.   r10,r9,16384
 540:	41 82 fc b8 	beq     1f8 <do_page_fault+0x1f8>

This patch creates a local var called 'is_user' which contains the
result of user_mode(regs)

With the patch:

  20:	81 03 00 84 	lwz     r8,132(r3)
  48:	55 09 97 fe 	rlwinm  r9,r8,18,31,31
  58:	2e 09 00 00 	cmpwi   cr4,r9,0
  5c:	40 92 00 0c 	bne     cr4,68 <do_page_fault+0x68>

  88:	41 b2 01 90 	beq     cr4,218 <do_page_fault+0x218>

  d4:	40 92 01 d0 	bne     cr4,2a4 <do_page_fault+0x2a4>

 120:	41 b2 00 f8 	beq     cr4,218 <do_page_fault+0x218>

 138:	41 b2 ff a0 	beq     cr4,d8 <do_page_fault+0xd8>

 1d4:	40 92 00 e0 	bne     cr4,2b4 <do_page_fault+0x2b4>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The result of (trap == 0x400) is already in is_exec.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Function store_updates_sp() checks whether the faulting
instruction is a store updating r1. Therefore we can limit its calls
to store exceptions.

This patch is an improvement of commit a7a9dcd8 ("powerpc: Avoid
taking a data miss on every userspace instruction miss")

With the same microbenchmark app, run with 500 as argument, on an
MPC885 we get:

Before this patch: 152000 DTLB misses
After this patch:  147000 DTLB misses
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

This function has not been used since commit 9494a1e8
("powerpc: use generic fixmap.h)
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The check in hpte_find() should be < and not <= for PAGE_OFFSET
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Add --orphan-handling=warn to final link flags. This ensures we can
handle all sections explicitly. This would have caught subtle breakage
such as 7de3b27b at build-time.

Also bring existing orphan sections into the fold:
- .text.hot and .text.unlikely are compiler generated sections.
- .sdata2, .dynsbss, .plt are used by PPC32
- We previously did not specify DWARF_DEBUG or STABS_DEBUG
- DWARF_DEBUG did not include all DWARF sections that can be emitted
- A number of sections are unused and can be discarded.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Use a tool to check that the location of "fixed sections" are where
we expected them to be, which catches cases the linker script can't
(stubs being added to start of .text section), and which ends up
being neater.

Sample output:

  ERROR: start_text address is c000000000008100, should be c000000000008000
  ERROR: see comments in arch/powerpc/tools/head_check.sh
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fold in fix from Nick for 4.6 era toolchains]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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