MIPS: math-emu: Make microMIPS branch delay slot emulation work

Complement commit 102cedc32a6e ("MIPS: microMIPS: Floating point
support.") which introduced microMIPS FPU emulation, but did not adju

MIPS: math-emu: Make microMIPS branch delay slot emulation work

Complement commit 102cedc32a6e ("MIPS: microMIPS: Floating point
support.") which introduced microMIPS FPU emulation, but did not adjust
the encoding of the BREAK instruction used to terminate the branch delay
slot emulation frame. Consequently the execution of any such frame is
indeterminate and, depending on CPU configuration, will result in random
code execution or an offending program being terminated with SIGILL.

This is because the regular MIPS BREAK instruction is encoded with the 0
major and the 0xd minor opcode, however in the microMIPS instruction set
this major/minor opcode pair denotes an encoding reserved for the DSP
ASE. Instead the microMIPS BREAK instruction is encoded with the 0
major and the 0x7 minor opcode.

Use the correct BREAK encoding for microMIPS FPU emulation then.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12174/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

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MIPS: math-emu: dsemul: Fix ill formatting of microMIPS part

Correct formatting breakage introduced with commit 102cedc32a6e ("MIPS:
microMIPS: Floating point support."), so that further changes to

MIPS: math-emu: dsemul: Fix ill formatting of microMIPS part

Correct formatting breakage introduced with commit 102cedc32a6e ("MIPS:
microMIPS: Floating point support."), so that further changes to this
code can be consistent.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12173/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

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MIPS: math-emu: Correctly handle NOP emulation

Fix an issue introduced with commit 9ab4471c9f1b ("MIPS: math-emu:
Correct delay-slot exception propagation") where the emulation of a NOP
instruction

MIPS: math-emu: Correctly handle NOP emulation

Fix an issue introduced with commit 9ab4471c9f1b ("MIPS: math-emu:
Correct delay-slot exception propagation") where the emulation of a NOP
instruction signals the need to terminate the emulation loop. This in
turn, if the PC has not changed from the entry to the loop, will cause
the kernel to terminate the program with SIGILL.

Consider this program:

static double div(double d)
{
do
d /= 2.0;
while (d > .5);
return d;
}

int main(int argc, char **argv)
{
return div(argc);
}

which gets compiled to the following binary code:

00400490 <main>:
400490: 44840000 mtc1 a0,$f0
400494: 3c020040 lui v0,0x40
400498: d44207f8 ldc1 $f2,2040(v0)
40049c: 46800021 cvt.d.w $f0,$f0
4004a0: 46220002 mul.d $f0,$f0,$f2
4004a4: 4620103c c.lt.d $f2,$f0
4004a8: 4501fffd bc1t 4004a0 <main+0x10>
4004ac: 00000000 nop
4004b0: 4620000d trunc.w.d $f0,$f0
4004b4: 03e00008 jr ra
4004b8: 44020000 mfc1 v0,$f0
4004bc: 00000000 nop

Where the FPU emulator is used, depending on the number of command-line
arguments this code will either run to completion or terminate with
SIGILL.

If no arguments are specified, then BC1T will not be taken, NOP will not
be emulated and code will complete successfully.

If one argument is specified, then BC1T will be taken once and NOP will
be emulated. At this point the entry PC value will be 0x400498 and the
new PC value, set by `mips_dsemul' will be 0x4004a0, the target of BC1T.
The emulation loop will terminate, but SIGILL will not be issued,
because the PC has changed. The FPU emulator will be entered again and
on the second execution BC1T will not be taken, NOP will not be emulated
and code will complete successfully.

If two or more arguments are specified, then the first execution of BC1T
will proceed as above. Upon reentering the FPU emulator the emulation
loop will continue to BC1T, at which point the branch will be taken and
NOP emulated again. At this point however the entry PC value will be
0x4004a0, the same as the target of BC1T. This will make the emulator
conclude that execution has not advanced and therefore an unsupported
FPU instruction has been encountered, and SIGILL will be sent to the
process.

Fix the problem by extending the internal API of `mips_dsemul', making
it return -1 if no delay slot emulation frame has been made, the
instruction has been handled and execution of the emulation loop needs
to continue as if nothing happened. Remove code from `mips_dsemul' to
reproduce steps made by the emulation loop at the conclusion of each
iteration, as those will be reached normally now. Adjust call sites
accordingly. Document the API.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12172/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

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Merge branch 'next' into for-linus

Prepare first round of input updates for 4.3 merge window.

Merge branch 'x86/urgent' into core/efi, to pick up a pending EFI fix

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

Merge remote-tracking branch 'net-next/master' into mac80211-next

Merge net-next to get some driver changes that patches depend
on (in order to avoid conflicts).

Signed-off-by: Johannes Berg <johan

Merge remote-tracking branch 'net-next/master' into mac80211-next

Merge net-next to get some driver changes that patches depend
on (in order to avoid conflicts).

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

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Merge remote-tracking branch 'asoc/fix/rt5645' into asoc-fix-rt5645

Merge branch 'for-4.3-rc/ti-clk-fixes' of https://github.com/t-kristo/linux-pm into clk-fixes

Pull fixes from Tero Kristo:

"A few TI clock driver fixes to pull against 4.3-rc"

* 'for-4.3-rc/ti-clk

Merge branch 'for-4.3-rc/ti-clk-fixes' of https://github.com/t-kristo/linux-pm into clk-fixes

Pull fixes from Tero Kristo:

"A few TI clock driver fixes to pull against 4.3-rc"

* 'for-4.3-rc/ti-clk-fixes' of https://github.com/t-kristo/linux-pm: (3 commits)
clk: ti: dflt: fix enable_reg validity check
clk: ti: fix dual-registration of uart4_ick
clk: ti: clk-7xx: Remove hardwired ABE clock configuration

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Merge remote-tracking branch 'airlied/drm-next' into drm-intel-next

Backmerge to catch up with 4.3. slightly more involved conflict in the
irq code, but nothing beyond adjacent changes.

Signed-off-

Merge remote-tracking branch 'airlied/drm-next' into drm-intel-next

Backmerge to catch up with 4.3. slightly more involved conflict in the
irq code, but nothing beyond adjacent changes.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

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Merge tag 'v4.3-rc3' into next

Merge with Linux 4.3-rc3 to bring in MFD DA9062 changes to merge DA9062
OnKey driver.

Merge tag 'v4.3-rc2' into k.o/for-4.3-v1

Linux 4.3-rc2

Merge tag 'v4.3-rc2' into topic/drm-misc

Backmerge Linux 4.3-rc2 because of conflicts in the dp helper code
between bugfixes and new code. Just adjacent lines really.

On top of that there's a silen

Merge tag 'v4.3-rc2' into topic/drm-misc

Backmerge Linux 4.3-rc2 because of conflicts in the dp helper code
between bugfixes and new code. Just adjacent lines really.

On top of that there's a silent conflict in the new fsl-dcu driver
merged into 4.3 and

commit 844f9111f6f54f88eb2f0fac121b82ce77193866
Author: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Date: Wed Sep 2 10:42:40 2015 +0200

drm/atomic: Make prepare_fb/cleanup_fb only take state, v3.

which Thierry Reding spotted and provided a fixup for.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

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Merge branch 'for-linus' into for-next

Merge tag 'v4.3-rc1' into spi-fix-doc

Linux 4.3-rc1

Merge branch 'fixes-rc1' into omap-for-v4.3/fixes

Merge tag 'v4.3-rc1' into MTD -next development

Merge tag 'v4.3-rc1' into patchwork

Linux 4.3-rc1

* tag 'v4.3-rc1': (11838 commits)
Linux 4.3-rc1
blk: rq_data_dir() should not return a boolean
writeback: plug writeback in wb_writeback() an

Merge tag 'v4.3-rc1' into patchwork

Linux 4.3-rc1

* tag 'v4.3-rc1': (11838 commits)
Linux 4.3-rc1
blk: rq_data_dir() should not return a boolean
writeback: plug writeback in wb_writeback() and writeback_inodes_wb()
thermal: fix intel PCH thermal driver mismerge
ARCv2: [axs103_smp] Reduce clk for SMP FPGA configs
revert "ocfs2/dlm: use list_for_each_entry instead of list_for_each"
mm/early_ioremap: add explicit #include of asm/early_ioremap.h
fs/seq_file: convert int seq_vprint/seq_printf/etc... returns to void
selftests: enhance membarrier syscall test
selftests: add membarrier syscall test
sys_membarrier(): system-wide memory barrier (generic, x86)
MODSIGN: fix a compilation warning in extract-cert
Revert "writeback: plug writeback at a high level"
scsi_dh: fix randconfig build error
target: use stringify.h instead of own definition
target/user: Fix UFLAG_UNKNOWN_OP handling
target: Remove no-op conditional
target/user: Remove unused variable
target: Fix max_cmd_sn increment w/o cmdsn mutex regressions
target: Attach EXTENDED_COPY local I/O descriptors to xcopy_pt_sess
...

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Merge tag 'v4.3-rc1' into perf/core, to refresh the tree

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

Merge tag 'v4.3-rc1' into locking/core, to refresh the tree

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

Merge tag 'v4.3-rc1' into sched/core, to refresh the branch

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

Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus

Pull MIPS updates from Ralf Baechle:
"This is the main pull request for 4.3 for MIPS. Here's the summary:

Three f

Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus

Pull MIPS updates from Ralf Baechle:
"This is the main pull request for 4.3 for MIPS. Here's the summary:

Three fixes that didn't make 4.2-stable:

- a -Os build might compile the kernel using the MIPS16 instruction
set but the R2 optimized inline functions in <uapi/asm/swab.h> are
implemented using 32-bit wide instructions which is invalid.

- a build error in pgtable-bits.h for a particular kernel
configuration.

- accessing registers of the CM GCR might have been compiled to use
64 bit accesses but these registers are onl 32 bit wide.

And also a few new bits:

- move the ATH79 GPIO driver to drivers/gpio

- the definition of IRQCHIP_DECLARE has moved to linux/irqchip.h,
change ATH79 accordingly.

- fix definition of pgprot_writecombine

- add an implementation of dma_map_ops.mmap

- fix alignment of quiet build output for vmlinuz link

- BCM47xx: Use kmemdup rather than duplicating its implementation

- Netlogic: Fix 0x0x prefixes of constants.

- merge Bjorn Helgaas' series to remove most of the weak keywords
from function declarations.

- CP0 and CP1 registers are best considered treated as unsigned
values to avoid large values from becoming negative values.

- improve support for the MIPS GIC timer.

- enable common clock framework for Malta and SEAD3.

- a number of improvments and fixes to dump_tlb().

- document the MIPS TLB dump functionality in Magic SysRq.

- Cavium Octeon CN68XX improvments.

- NetLogic improvments.

- irq: Use access helper irq_data_get_affinity_mask.

- handle MSA unaligned accesses.

- a number of R6-related math-emu fixes.

- support for I6400.

- improvments to MSA support.

- add uprobes support.

- move from deprecated __initcall to arch_initcall.

- remove finish_arch_switch().

- IRQ cleanups by Thomas Gleixner.

- migrate to new 'set-state' interface.

- random small cleanups"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (148 commits)
MIPS: UAPI: Fix unrecognized opcode WSBH/DSBH/DSHD when using MIPS16.
MIPS: Fix alignment of quiet build output for vmlinuz link
MIPS: math-emu: Remove unused handle_dsemul function declaration
MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction
MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction
MIPS: math-emu: Add support for the MIPS R6 CLASS FPU instruction
MIPS: math-emu: Add support for the MIPS R6 RINT FPU instruction
MIPS: math-emu: Add support for the MIPS R6 MSUBF FPU instruction
MIPS: math-emu: Add support for the MIPS R6 MADDF FPU instruction
MIPS: math-emu: Add support for the MIPS R6 SELNEZ FPU instruction
MIPS: math-emu: Add support for the MIPS R6 SELEQZ FPU instruction
MIPS: math-emu: Add support for the CMP.condn.fmt R6 instruction
MIPS: inst.h: Add new MIPS R6 FPU opcodes
MIPS: Octeon: Fix management port MII address on Kontron S1901
MIPS: BCM47xx: Use kmemdup rather than duplicating its implementation
STAGING: Octeon: Use common helpers for determining interface and port
MIPS: Octeon: Support interfaces 4 and 5
MIPS: Octeon: Set up 1:1 mapping between CN68XX PKO queues and ports
MIPS: Octeon: Initialize CN68XX PKO
STAGING: Octeon: Support CN68XX style WQE
...

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Merge branch 'next' into for-linus

Prepare first round of input updates for 4.3 merge window.

MIPS: math-emu: Remove unused handle_dsemul function declaration

handle_dsemul does not exist and it's not being used in the code at all
so remove its declaration. The deliberate DS emulation except

MIPS: math-emu: Remove unused handle_dsemul function declaration

handle_dsemul does not exist and it's not being used in the code at all
so remove its declaration. The deliberate DS emulation exception is
handled by the do_dsemulret C code.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10950/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

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Merge tag 'v4.2-rc3' into next

Sync up with Linux 4.2-rc3 to bring in infrastructure (OF) pieces.

Merge branches 'for-4.2/i2c-hid', 'for-4.2/lenovo', 'for-4.2/plantronics', 'for-4.2/rmi', 'for-4.2/sensor-hub', 'for-4.2/sjoy', 'for-4.2/sony' and 'for-4.2/wacom' into for-linus

Conflicts:
drivers/

Merge branches 'for-4.2/i2c-hid', 'for-4.2/lenovo', 'for-4.2/plantronics', 'for-4.2/rmi', 'for-4.2/sensor-hub', 'for-4.2/sjoy', 'for-4.2/sony' and 'for-4.2/wacom' into for-linus

Conflicts:
drivers/hid/wacom_wac.c

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