Building of EXYNOS5420_MCPM with disabled SUSPEND fails:
arch/arm/mach-exynos/built-in.o: In function `exynos_mcpm_init':
arch/arm/mach-exynos/mcpm-exynos.c:361: undefined reference to `mcpm_loopback'

The exynos_mcpm_init() in mcp-exynos.c calls mcpm_loopback() which
depends on cpu_suspend function (ARM_CPU_SUSPEND).
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: NNicolas Pitre <nico@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The Chromebook firmware doesn't enable the CCI for the boot cpu, and
arguably it shouldn't have to either. Let's have the kernel handle the

CCI on its own for the boot CPU the same way it does it for secondary CPUs
by using the MCPM loopback.

This allows to boot all 8 cores on exynos5420-peach-pit,
exynos5800-peach-pi and ARM Chromebook 2.
Signed-off-by: NNicolas Pitre <nico@linaro.org>
Tested-by: NTushar Behera <tushar.b@samsung.com>
Reviewed-by: NKevin Hilman <khilman@linaro.org>
Tested-by: NKevin Hilman <khilman@linaro.org>
Tested-by: NDoug Anderson <dianders@chromium.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This is not strictly needed on TC2 but still a good idea to exercise
that code.
Signed-off-by: Nnicolas Pitre <nico@linaro.org>
Reviewed-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The kernel already has the responsibility to handle resources such as the

CCI when hotplugging CPUs, during the booting of secondary CPUs, and when
resuming from suspend/idle.  It would be more coherent and less confusing
if the CCI for the boot CPU (or cluster)  was also initialized by the
kernel rather than expecting the firmware/bootloader to do it and only in
that case. After all, the kernel has all the necessary code already and
the bootloader shouldn't have to care at all.

The CCI may be turned on only when the cache is off. Leveraging the CPU
suspend code to loop back through the low-level MCPM entry point is all
that is needed to properly turn on the CCI from the kernel by using the
same code as during secondary boot.

Let's provide a generic MCPM loopback function that can be invoked by
backend initialization code to set things (CCI or similar) on the boot
CPU just as it is done for the other CPUs.
Signed-off-by: NNicolas Pitre <nico@linaro.org>
Reviewed-by: NKevin Hilman <khilman@linaro.org>
Tested-by: NKevin Hilman <khilman@linaro.org>
Tested-by: NDoug Anderson <dianders@chromium.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

After applying patch:
	"ARM: 8078/1: get rid of hardcoded assumptions about kernel stack size"

following build failure happens on iop13xx platform:

   In file included from include/linux/srcu.h:33:0,
                    from include/linux/notifier.h:15,
                    from include/linux/reboot.h:5,
                    from arch/arm/mach-iop13xx/include/mach/iop13xx.h:6,
                    from arch/arm/mach-iop13xx/include/mach/hardware.h:14,
                    from arch/arm/mach-iop13xx/include/mach/memory.h:4,
                    from arch/arm/include/asm/memory.h:24,
                    from arch/arm/include/asm/page.h:163,
                    from arch/arm/include/asm/thread_info.h:17,
                    from include/linux/thread_info.h:54,
                    from include/asm-generic/preempt.h:4,
                    from arch/arm/include/generated/asm/preempt.h:1,
                    from include/linux/preempt.h:18,
                    from include/linux/spinlock.h:50,
                    from include/linux/seqlock.h:35,
                    from include/linux/time.h:5,
                    from include/uapi/linux/timex.h:56,
                    from include/linux/timex.h:56,
                    from include/linux/sched.h:19,
                    from arch/arm/kernel/asm-offsets.c:13:
   include/linux/rcupdate.h: In function '__rcu_read_lock':
>> include/linux/rcupdate.h:220:2: error: implicit declaration of function 'preempt_disable' [-Werror=implicit-function-declaration]
     preempt_disable();

The problem here is recursive header inclusion which could be avoided by
removing linux/reboot.h from mach/iop13xxx.h.
linux/reboot.h in include/mach/iop13xx.h is needed only for enum reboot_mode,
so header it could be replaced with a enum declaration.

Whatever patch "ARM: 8078/1: get rid of hardcoded assumptions about kernel stack size"
does, I think it's good to avoid unnecessary header inclusion here in any case.
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Reported-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrey Ryabinin <a.ryabinin@samsung.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Changing kernel stack size on arm is not as simple as it should be:
1) THREAD_SIZE macro doesn't respect PAGE_SIZE and THREAD_SIZE_ORDER
2) stack size is hardcoded in get_thread_info macro

This patch fixes it by calculating THREAD_SIZE and thread_info address
taking into account PAGE_SIZE and THREAD_SIZE_ORDER.

Now changing stack size becomes simply changing THREAD_SIZE_ORDER.
Signed-off-by: NAndrey Ryabinin <a.ryabinin@samsung.com>
Acked-by: NNicolas Pitre <nico@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

As we are now using the C preprocessor, we do not need to use sed to
edit constants in this file, and then pass the resulting file through
the C preprocessor.  Instead, rely solely on the C preprocessor to
rewrite TEXT_START and BSS_ADDR.
Acked-by: NNicolas Pitre <nico@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

All known BE8-capable systems have LE bootloaders, so we need to ensure
that the magic number and image start/end values are in little endian
format.

[ben.dooks@codethink.co.uk: from nico's original email on this subject]
[taras.kondratiuk@linaro.org: removed lds.S->lds rule, added target to extra-y]
Signed-off-by: NNicolas Pitre <nico@fluxnic.net>
Signed-off-by: NBen Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: NTaras Kondratiuk <taras.kondratiuk@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The legacy OMAP DMA API is now deprecated; all remaining users should
now convert over ASAP to using the DMA engine API instead of the OMAP
private API.
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

On the syscall tracing path, we call out to secure_computing() to allow
seccomp to check the syscall number being attempted. As part of this, a
SIGTRAP may be sent to the tracer and the syscall could be re-written by
a subsequent SET_SYSCALL ptrace request. Unfortunately, this new syscall
is ignored by the current code unless TIF_SYSCALL_TRACE is also set on
the current thread.

This patch slightly reworks the enter path of the syscall tracing code
so that we always reload the syscall number from
current_thread_info()->syscall after the potential ptrace traps.
Acked-by: NKees Cook <keescook@chromium.org>
Tested-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Commit 1c2f87c2 (ARM: 8025/1: Get rid of meminfo) changed find_limits
to use memblock_get_current_limit for calculating the max_low pfn.
nommu targets never actually set a limit on memblock though which
means memblock_get_current_limit will just return the default
value. Set the memblock_limit to be the end of DDR to make sure
bounds are calculated correctly.
Signed-off-by: NLaura Abbott <lauraa@codeaurora.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The CFI mapping is now perfect so we can expose the top block, read only.
There isn't much to read, though, just the sharpsl_params values.
Signed-off-by: NAndrea Adami <andrea.adami@gmail.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Reverts commit d26b17ed
ARM: sa1100: collie.c: fall back to jedec_probe flash detection

Unfortunately the detection was challenged on the defective unit used for tests:
one of the NOR chips did not respond to the CFI query.
Moreover that bad device needed extra delays on erase-suspend/resume cycles.

Tested personally on 3 different units and with feedback of two other users.
Signed-off-by: NAndrea Adami <andrea.adami@gmail.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The sync_phys variable has been replaced by link time computation in
mcpm_head.S before the code was submitted upstream.
Signed-off-by: NNicolas Pitre <nico@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

When a PL310 cache is used on a system that provides hardware
coherency, the outer cache sync operation is useless, and can be
skipped. Moreover, on some systems, it is harmful as it causes
deadlocks between the Marvell coherency mechanism, the Marvell PCIe
controller and the Cortex-A9.

To avoid this, this commit introduces a new Device Tree property
'arm,io-coherent' for the L2 cache controller node, valid only for the
PL310 cache. It identifies the usage of the PL310 cache in an I/O
coherent configuration. Internally, it makes the driver disable the
outer cache sync operation.

Note that technically speaking, a fully coherent system wouldn't
require any of the other .outer_cache operations. However, in
practice, when booting secondary CPUs, these are not yet coherent, and
therefore a set of cache maintenance operations are necessary at this
point. This explains why we keep the other .outer_cache operations and
only ->sync is disabled.

While in theory any write to a PL310 register could cause the
deadlock, in practice, disabling ->sync is sufficient to workaround
the deadlock, since the other cache maintenance operations are only
used in very specific situations.

Contrary to previous versions of this patch, this new version does not
simply NULL-ify the ->sync member, because the l2c_init_data
structures are now 'const' and therefore cannot be modified, which is
a good thing. Therefore, this patch introduces a separate
l2c_init_data instance, called of_l2c310_coherent_data.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Kconfig doesn't select CRC32 so it's possible to build a Lasat kernel
without CONFIG_CRC32 resulting in a build error:

  LD      vmlinux
arch/mips/built-in.o: In function `lasat_init_board_info':
(.text+0x22c): undefined reference to `crc32_le'
arch/mips/built-in.o: In function `lasat_write_eeprom_info':
(.text+0x7fc): undefined reference to `crc32_le'
make: *** [vmlinux] Error 1
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Previously, the lower limit for the MIPS SC initialization loop was
set incorrectly allowing one extra loop leading to writes
beyond the MSC ioremap'd space. More precisely, the value of the 'imp'
in the last loop increased beyond the msc_irqmap_t boundaries and
as a result of which, the 'n' variable was loaded with an incorrect
value. This value was used later on to calculate the offset in the
MSC01_IC_SUP which led to random crashes like the following one:

CPU 0 Unable to handle kernel paging request at virtual address e75c0200,
epc == 8058dba4, ra == 8058db90
[...]
Call Trace:
[<8058dba4>] init_msc_irqs+0x104/0x154
[<8058b5bc>] arch_init_irq+0xd8/0x154
[<805897b0>] start_kernel+0x220/0x36c

Kernel panic - not syncing: Attempted to kill the idle task!

This patch fixes the problem
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>
Reviewed-by: NJames Hogan <james.hogan@imgtec.com>
Cc: stable@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7118/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

When allocating stack space for BPF memwords we need to use the
appropriate 32 or 64-bit instruction to avoid losing the top 32 bits
of the stack pointer.
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: netdev@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7135/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

When loading a pointer to register we need to use the appropriate
32 or 64bit instruction to preserve the pointers' top 32bits.
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: netdev@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7180/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The skb->pkt_type field is defined as follows:

u8 pkt_type:3,
   fclone:2,
   ipvs_property:1,
   peeked:1,
   nf_trace:1

resulting to the following layout in big-endian systems

[pkt_type][fclone][ipvs_propery][peeked][nf_trace]
^                                                ^
|                                                |
LSB                                             MSB

As a result, the existing code did not work because it was trying to
match pkt_type == 7 whereas in reality it is 7<<5 on big-endian
systems.

This has been fixed in the interpreter in
0dcceabb
"net: filter: fix SKF_AD_PKTTYPE extension on big-endian"

The fix is to look for 7<<5 on big-endian systems for the pkt_type
field, and shift by 5 so the packet type will be at the lower 3 bits
of the A register.
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: netdev@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7132/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Remove BUG_ON() if the shift immediate is >=32 to avoid kernel crashes
due to malicious user input. If the shift immediate is >= 32,
we simply load the destination register with 0 since only
32-bit instructions are used by JIT so this will do the
correct thing even on MIPS64.
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: netdev@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7179/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Previously, update_on_xread() only set the reset flag if SEEN_X hasn't
been set already. However, SEEN_X is used to indicate that X is used
as destination or source register so there are some cases where X
is only used as source register and we really need to make sure that it
has been initialized in time. As a result of which, drop this function and
always set X to zero if it's used in any of the opcodes.
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: netdev@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7133/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

is_range() was meant to check whether the number is within
the s16 range or not. However the return values and consumers expected
the exact opposite. We fix that by inverting the logic in the function
to return 'true' for < s16 and 'false' for > s16.
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>
Reported-by: NAlexei Starovoitov <ast@plumgrid.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: netdev@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7131/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

We should prevent spamming the logs during normal execution of bpf-jit.
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>
Suggested-by: NAlexei Starovoitov <ast@plumgrid.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: netdev@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7129/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

If VLAN_TAG_PRESENT is not zero, then return 1 as expected by
classic BPF. Otherwise return 0.
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: netdev@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7128/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Using VLAN_VID_MASK is not correct to get the vlan tag. Use
~VLAN_PRESENT_MASK instead and make sure it's u16 so the top 16-bits
will be removed. This will ensure that the emit_andi() code will not
treat this as a big 32-bit unsigned value.
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: netdev@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7127/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The sltiu and sltu instructions will set the scratch register
to 1 if A <= X|K so fix the emitted branch conditional to check
for scratch != zero rather than scratch >= zero which would complicate
the resuling branch logic given that MIPS does not have a BGT or BGET
instructions to compare general purpose registers directly.
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: netdev@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7126/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The SKF_AD_PKTTYPE uses the skb pointer so make sure it's in the
flags so it will be initialized in time.
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: netdev@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7125/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The VLAN_VID_MASK and VLAN_TAG_PRESENT are immediates, so using
'and' which expects 3 registers will produce wrong results. Fix
this by using the 'andi' instruction.
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: netdev@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7124/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Previously, the negative offset was not checked leading to failures
due to trying to load data beyond the skb struct boundaries. Until we
have proper asm helpers in place, it's best if we return ENOSUPP if K
is negative when trying to JIT the filter or 0 during runtime if we
do an indirect load where the value of X is unknown during build time.
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: netdev@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7123/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Reading from the HI register to get the division result is wrong.
The quotient is placed in the LO register.
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: netdev@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7122/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Commit d6b3314b "MIPS: uasm: Add lh uam
instruction" added the 'lh' micro-assembler instruction but it used the
'lw' opcode for it. Fix it by using the correct 'lh' opcode.
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7121/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

It will be used later on by bpf-jit
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Markos Chandras <markos.chandras@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/7120/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

It will be used later on by the SLT instruction.
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7119/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

  mips: allmodconfig fails in 3.16-rc1 with lots of undefined symbols.

  arch/mips/net/bpf_jit.c: In function 'is_load_to_a':
  arch/mips/net/bpf_jit.c:559:7: error: 'BPF_S_LD_W_LEN' undeclared (first use in this function)
  arch/mips/net/bpf_jit.c:559:7: note: each undeclared identifier is reported only once for each function it appears in
  arch/mips/net/bpf_jit.c:560:7: error: 'BPF_S_LD_W_ABS' undeclared (first use in this function)
  [...]

The reason behind this is that 34805931 ("net: filter: get rid of
BPF_S_* enum") was routed via net-next tree, that takes all BPF-related
changes, at a time where MIPS BPF JIT was not part of net-next, while
c6610de3 ("MIPS: net: Add BPF JIT") was routed via mips arch tree
and went into mainline within the same merge window. Thus, fix it up by
converting BPF_S_* in a similar fashion as in 34805931 for MIPS.
Reported-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NDaniel Borkmann <dborkman@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-kernel@vger.kernel.org <linux-kernel@vger.kernel.org>
Cc: Linux MIPS Mailing List <linux-mips@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/7099/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This reverts commit eec43a22 "MIPS: Save/restore MSA context around
signals" and the MSA parts of ca750649 "MIPS: kernel: signal:
Prevent save/restore FPU context in user memory" (the restore path of
which appears incorrect anyway...).

The reverted patch took care not to break compatibility with userland
users of struct sigcontext, but inadvertantly changed the offset of the
uc_sigmask field of struct ucontext. Thus Linux v3.15 breaks the
userland ABI. The MSA context will need to be saved via some other
opt-in mechanism, but for now revert the change to reduce the fallout.

This will have minimal impact upon use of MSA since the only supported
CPU which includes it (the P5600) is 32-bit and therefore requires that
the experimental CONFIG_MIPS_O32_FP64_SUPPORT Kconfig option be selected
before the kernel will set FR=1 for a task, a requirement for MSA use.
Thus the users of MSA are limited to known small groups of people & this
patch won't be breaking any previously working MSA-using userland
outside of experimental settings.

[ralf@linux-mips.org: Fixed rejects.]

Cc: stable@vger.kernel.org
Reported-by: NJoseph S. Myers <joseph@codesourcery.com>
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7107/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The fix in the preceeding commit did do exactly the same thing in two
places showing some code cleanup was due.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

icaches are not snooped hence not cohrent in SMP setups which means
kernel has to do cross core calls to ensure the same.

The leaf routine __ic_line_inv_vaddr() now does cross core calls.

__sync_icache_dcache() is affected due to this:

* local dcache line flushed ahead of remote icache inv requests
* can't disable interrupts anymore, since
      __ic_line_inv_vaddr()->on_each_cpu() can deadlock.

| WARNING: CPU: 0 PID: 1 at kernel/smp.c:374
| smp_call_function_many+0x25a/0x2c4()
|
|  init_kprobes+0x90/0xc8
|     register_kprobe+0x1d6/0x510
|	__sync_icache_dcache+0x28/0x80
|
|	    DISABLE IRQ
|
|	    __ic_line_inv_vaddr
|		on_each_cpu
|		     smp_call_function_many+0x25a/0x2c4   --> WARN
|			__ic_line_inv_vaddr_local
|	    __dc_line_op

* TODO: Needs to use mask of relevant CPUs to avoid broadcasting
Signed-off-by: NNoam Camus <noamc@ezchip.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Handle it just like timer. Current request_percpu_irq() would fail on
non-boot cpus and thus IRQ will remian unmasked on those cpus.

[vgupta: fix changelong]
Signed-off-by: NNoam Camus <noamc@ezchip.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

This patch adds implementation of GET_THREAD_AREA ptrace request type. This
is required by GDB to debug NPTL applications.
Signed-off-by: NAnton Kolesov <Anton.Kolesov@synopsys.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>