Commit graph

571531 commits

Author SHA1 Message Date
Paul Burton
ad0828f49b UPSTREAM: MIPS: Sanitise coherentio semantics
The coherentio variable has previously been used as a boolean value,
indicating whether the user specified that coherent I/O should be
enabled or disabled. It failed to take into account the case where the
user does not specify any preference, in which case it makes sense that
we should default to coherent I/O if the hardware supports it
(hw_coherentio is non-zero).

Introduce an enum to clarify the 3 different values of coherentio & use
it throughout the code, modifying plat_device_is_coherent() &
r4k_cache_init() to take into account the default case.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Paul Burton <paul.burton@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/14347/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit f23020230e682a43cc4706cabb041bba469df2d6)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:32 -08:00
Paul Burton
bdb66e0786 UPSTREAM: MIPS: CPC: Provide default mips_cpc_default_phys_base to ignore CPC
Provide a default implementation of mips_cpc_default_phys_base() which
simply returns 0, and adjust mips_cpc_phys_base() to allow for
mips_cpc_default_phys_base() returning 0. This allows kernels which
include CPC support to be built without platform code & simply ignore
the CPC if it wasn't already enabled by the bootloader.

This fixes link failures such as the following from generic defconfigs:

   arch/mips/built-in.o: In function `mips_cpc_phys_base':
   arch/mips/kernel/mips-cpc.c:47: undefined reference to `mips_cpc_default_phys_base'

[ralf@linux-mips.org: changed prototype for coding style compliance.]

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14401/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 682c1e52215da4a3e89c14aad60bfc0d400b025f)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:32 -08:00
Paul Burton
9c0e042c61 UPSTREAM: MIPS: generic: Introduce generic DT-based board support
Introduce a "generic" platform, which aims to be board-agnostic by
making use of device trees passed by the boot protocol defined in the
MIPS UHI (Universal Hosting Interface) specification. Provision is made
for supporting boards which use a legacy boot protocol that can't be
changed, but adding support for such boards or any others is left to
followon patches.

Right now the built kernels expect to be loaded to 0x80100000, ie. in
kseg0. This is fine for the vast majority of MIPS platforms, but
nevertheless it would be good to remove this limitation in the future by
mapping the kernel via the TLB such that it can be loaded anywhere & map
itself appropriately.

Configuration is handled by dynamically generating configs using
scripts/kconfig/merge_config.sh, somewhat similar to the way powerpc
makes use of it. This allows for variations upon the configuration, eg.
differing architecture revisions or subsets of driver support for
differing boards, to be handled without having a large number of
defconfig files.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14353/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit eed0eabd12ef061821cbfa20d903476e07645320)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:32 -08:00
Paul Burton
62725e3e7d UPSTREAM: MIPS: Support generating Flattened Image Trees (.itb)
Add support for generating kernel images in the Flattened Image Tree
(.itb) format as supported by U-Boot. This format is essentially a
Flattened Device Tree binary containing images (kernels, DTBs, ramdisks)
and configurations which link those images together. The big advantages
of FIT images over the uImage format are:

  - We can include FDTs in the kernel image in a way that the bootloader
    can extract it & manipulate it before providing it to the kernel.
    Thus we can ship FDTs as part of the kernel giving us the advantages
    of being able to develop & maintain the DT within the kernel tree,
    but also have the benefits of the bootloader being able to
    manipulate the FDT. Example uses for this would be to inject the
    kernel command line into the chosen node, or to fill in the correct
    memory size.

  - We can include multiple configurations in a single kernel image.
    This means that a single FIT image can, given appropriate
    bootloaders, be booted on different boards with the bootloader
    selecting an appropriate configuration & providing the correct FDT
    to the kernel.

  - We can support a multitude of hashes over the data.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14352/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit cf2a5e0bb4c66e8c43caf9f1be93a1bd7fd07b17)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:31 -08:00
Paul Burton
54c1aa3ea2 UPSTREAM: MIPS: Allow emulation for unaligned [LS]DXC1 instructions
If an address error exception occurs for a LDXC1 or SDXC1 instruction,
within the cop1x opcode space, allow it to be passed through to the FPU
emulator rather than resulting in a SIGILL. This causes LDXC1 & SDXC1 to
be handled in a manner consistent with the more common LDC1 & SDC1
instructions.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Tested-by: Aurelien Jarno <aurelien@aurel32.net>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13143/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit e70ac023f9515c70cf2b291a294f0f250df29847)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:31 -08:00
Douglas Leung
da8a6c79d7 UPSTREAM: MIPS: math-emu: Fix BC1EQZ and BC1NEZ condition handling
Correct the treatment of branching conditions for BC1EQZ and BC1NEZ
instructions in function isBranchInstr().

Previously, corresponding conditions were swapped, which in turn meant
that, for these two instructions, function isBranchInstr() returned
wrong value in its output parameter contpc.

This change is actually an extension of the fix done by the commit
93583e178ebf ("MIPS: math-emu: Fix BC1{EQ,NE}Z emulation"). That commit
dealt with a similar problem in function cop1Emulate(), while this
commit deals with condition handling in function isBranchInstr().
The code styles of changes in these two commits are kept as
consistent as possible.

Signed-off-by: Douglas Leung <douglas.leung@imgtec.com>
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
Cc: james.hogan@imgtec.com
Cc: leonid.yegoshin@imgtec.com
Cc: petar.jovanovic@imgtec.com
Cc: goran.ferenc@imgtec.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15489/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 8bcd84a4a37c88d8304ca3a64f0461a51487e239)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:31 -08:00
Aleksandar Markovic
4e734c6f34 UPSTREAM: MIPS: r2-on-r6-emu: Clear BLTZALL and BGEZALL debugfs counters
Add missing clearing of BLTZALL and BGEZALL emulation counters in
function mipsr2_stats_clear_show().

Previously, it was not possible to reset BLTZALL and BGEZALL
emulation counters - their value remained the same even after
explicit request via debugfs. As far as other related counters
are concerned, they all seem to be properly cleared.

This change affects debugfs operation only, core R2 emulation
functionality is not affected.

Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
Cc: james.hogan@imgtec.com
Cc: leonid.yegoshin@imgtec.com
Cc: douglas.leung@imgtec.com
Cc: petar.jovanovic@imgtec.com
Cc: miodrag.dinic@imgtec.com
Cc: goran.ferenc@imgtec.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15517/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 411dac79cc2ed80f7e348ccc23eb4d8b0ba9f6d5)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:31 -08:00
Leonid Yegoshin
4fed79c571 UPSTREAM: MIPS: r2-on-r6-emu: Fix BLEZL and BGTZL identification
Fix the problem of inaccurate identification of instructions BLEZL and
BGTZL in R2 emulation code by making sure all necessary encoding
specifications are met.

Previously, certain R6 instructions could be identified as BLEZL or
BGTZL. R2 emulation routine didn't take into account that both BLEZL
and BGTZL instructions require their rt field (bits 20 to 16 of
instruction encoding) to be 0, and that, at same time, if the value in
that field is not 0, the encoding may represent a legitimate MIPS R6
instruction.

This means that a problem could occur after emulation optimization,
when emulation routine tried to pipeline emulation, picked up a next
candidate, and subsequently misrecognized an R6 instruction as BLEZL
or BGTZL.

It should be said that for single pass strategy, the problem does not
happen because CPU doesn't trap on branch-compacts which share opcode
space with BLEZL/BGTZL (but have rt field != 0, of course).

Signed-off-by: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtech.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtech.com>
Reported-by: Douglas Leung <douglas.leung@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
Cc: james.hogan@imgtec.com
Cc: petar.jovanovic@imgtec.com
Cc: goran.ferenc@imgtec.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15456/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 5bba7aa4958e271c3ffceb70d47d3206524cf489)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:31 -08:00
Leonid Yegoshin
0075089fff UPSTREAM: MIPS: remove aliasing alignment if HW has antialising support
MIPS hardware may have an antialising support and it works even
page size is small.

Setup a shared memory aliasing mask to page size if hardware has
an antialising support. Big shared memory mask forces a disruption
in page address assignment and that corrupts Android library memory
handling.

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: cernekee@gmail.com
Cc: paul.gortmaker@windriver.com
Cc: kumba@gentoo.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11516/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit cb80b2a38bd609b2f5a650e9ab87ea50105ad5ea)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:31 -08:00
Jonas Gorski
f9b39ce8d4 BACKPORT: MIPS: store the appended dtb address in a variable
Instead of rewriting the arguments to match the UHI spec, store the
address of a appended or UHI supplied dtb in fw_supplied_dtb.

That way the original bootloader arugments are kept intact while still
making the use of an appended dtb invisible for mach code.

Mach code can still find out if it is an appended dtb by comparing
fw_arg1 with fw_supplied_dtb.

Signed-off-by: Jonas Gorski <jogo@openwrt.org>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: John Crispin <john@phrozen.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Alban Bedel <albeu@free.fr>
Cc: Daniel Gimpelevich <daniel@gimpelevich.san-francisco.ca.us>
Cc: Antony Pavlov <antonynpavlov@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13699/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 15f37e1588920e010f20b53f04af94e91b8ee714)

Conflicts:
	arch/mips/ath79/setup.c
	arch/mips/lantiq/prom.c
	arch/mips/pic32/pic32mzda/init.c
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:31 -08:00
Maciej W. Rozycki
fb0c12e677 UPSTREAM: MIPS: Fix FCSR Cause bit handling for correct SIGFPE issue
Sanitize FCSR Cause bit handling, following a trail of past attempts:

* commit 4249548454f7 ("MIPS: ptrace: Fix FP context restoration FCSR
regression"),

* commit 443c44032a ("MIPS: Always clear FCSR cause bits after
emulation"),

* commit 64bedffe49 ("MIPS: Clear [MSA]FPE CSR.Cause after
notify_die()"),

* commit b1442d39fa ("MIPS: Prevent user from setting FCSR cause
bits"),

* commit b54d2901517d ("Properly handle branch delay slots in connection
with signals.").

Specifically do not mask these bits out in ptrace(2) processing and send
a SIGFPE signal instead whenever a matching pair of an FCSR Cause and
Enable bit is seen as execution of an affected context is about to
resume.  Only then clear Cause bits, and even then do not clear any bits
that are set but masked with the respective Enable bits.  Adjust Cause
bit clearing throughout code likewise, except within the FPU emulator
proper where they are set according to IEEE 754 exceptions raised as the
operation emulated executed.  Do so so that any IEEE 754 exceptions
subject to their default handling are recorded like with operations
executed by FPU hardware.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14460/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 5a1aca4469fdccd5b74ba0b4e490173b2b447895)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:31 -08:00
Paul Gortmaker
1c7d67bedb UPSTREAM: MIPS: kernel: Audit and remove any unnecessary uses of module.h
Historically a lot of these existed because we did not have
a distinction between what was modular code and what was providing
support to modules via EXPORT_SYMBOL and friends.  That changed
when we forked out support for the latter into the export.h file.

This means we should be able to reduce the usage of module.h
in code that is obj-y Makefile or bool Kconfig.  The advantage
in doing so is that module.h itself sources about 15 other headers;
adding significantly to what we feed cpp, and it can obscure what
headers we are effectively using.

Since module.h was the source for init.h (for __init) and for
export.h (for EXPORT_SYMBOL) we consider each obj-y/bool instance
for the presence of either and replace as needed.

In the case of the n32/o32 files, we have to get rid of a couple
no-op MODULE_ tags to facilitate the module.h removal.  They piggy
back off the fs/ elf binary support, which is also a bool Kconfig.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14032/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit d9d5417755eda87db8e370e4dd2175fbd8814acc)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:31 -08:00
James Hogan
98561f4928 UPSTREAM: MIPS: c-r4k: Fix sigtramp SMP call to use kmap
Fix r4k_flush_cache_sigtramp() and local_r4k_flush_cache_sigtramp() to
flush the delay slot emulation trampoline cacheline through a kmap
rather than directly when the active_mm doesn't match that of the task
initiating the flush, a bit like local_r4k_flush_cache_page() does.

This would fix a corner case on SMP systems without hardware globalized
hit cache ops, where a migration to another CPU after the flush, where
that CPU did not have the same mm active at the time of the flush, could
result in stale icache content being executed instead of the trampoline,
e.g. from a previous delay slot emulation with a similar stack pointer.

This case was artificially triggered by replacing the icache flush with
a full indexed flush (not globalized on CM systems) and forcing the SMP
call to take place, with a test program that alternated two FPU delay
slots with a parent process repeatedly changing scheduler affinity.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13797/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit e523f289fe4d18d509f8827f8a293e8c5e4f51a1)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:31 -08:00
James Hogan
aff62c8fad UPSTREAM: MIPS: c-r4k: Fix protected_writeback_scache_line for EVA
The protected_writeback_scache_line() function is used by
local_r4k_flush_cache_sigtramp() to flush an FPU delay slot emulation
trampoline on the userland stack from the caches so it is visible to
subsequent instruction fetches.

Commit de8974e3f7 ("MIPS: asm: r4kcache: Add EVA cache flushing
functions") updated some protected_ cache flush functions to use EVA
CACHEE instructions via protected_cachee_op(), and commit 83fd43449b
("MIPS: r4kcache: Add EVA case for protected_writeback_dcache_line") did
the same thing for protected_writeback_dcache_line(), but
protected_writeback_scache_line() never got updated. Lets fix that now
to flush the right user address from the secondary cache rather than
some arbitrary kernel unmapped address.

This issue was spotted through code inspection, and it seems unlikely to
be possible to hit this in practice. It theoretically affect EVA kernels
on EVA capable cores with an L2 cache, where the icache fetches straight
from RAM (cpu_icache_snoops_remote_store == 0), running a hard float
userland with FPU disabled (nofpu). That both Malta and Boston platforms
override cpu_icache_snoops_remote_store to 1 suggests that all MIPS
cores fetch instructions into icache straight from L2 rather than RAM.

Fixes: de8974e3f7 ("MIPS: asm: r4kcache: Add EVA cache flushing functions")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13800/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 0758b116b4080d9a2a2a715bec6eee2cbd828215)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:31 -08:00
Ralf Baechle
66e81bda60 UPSTREAM: MIPS: Spelling fix lets -> let's
As noticed by Sergei in the discussion of Andrea Gelmini's patch series.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Reported-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
(cherry picked from commit 4939788eb8559754a120531c49ffa96bb30fee06)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:31 -08:00
Andrea Gelmini
d552d767e4 UPSTREAM: MIPS: R6: Fix typo
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Cc: macro@imgtec.com
Cc: paul.burton@imgtec.com
Cc: Leonid.Yegoshin@imgtec.com
Cc: trivial@kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13329/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit f5be47f5a4b74ca4bc58348a0b2a6aa4c8cba1be)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:31 -08:00
Maciej W. Rozycki
a8955d815e UPSTREAM: MIPS: traps: Correct the SIGTRAP debug ABI in do_watch' and do_trap_or_bp'
Follow our own rules set in <asm/siginfo.h> for SIGTRAP signals issued
from `do_watch' and `do_trap_or_bp' by setting the signal code to
TRAP_HWBKPT and TRAP_BRKPT respectively, for Watch exceptions and for
those Breakpoint exceptions whose originating BREAK instruction's code
does not have a special meaning.  Keep Trap exceptions unaffected as
these are not debug events.

No existing user software is expected to examine signal codes for these
signals as SI_KERNEL has been always used here.  This change makes the
MIPS port more like other Linux ports, which reduces the complexity and
provides for performance improvement in GDB.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Luis Machado <lgustavo@codesourcery.com>
Cc: linux-mips@linux-mips.org
Cc: gdb@sourceware.org
Patchwork: https://patchwork.linux-mips.org/patch/12758/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 3b143cca6e1397188f507a6c727f4108861ceb8b)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:31 -08:00
Paul Burton
23080a1ef2 UPSTREAM: MIPS: inst.h: Rename cbcond{0,1}_op to pop{1,3}0_op
The opcodes currently defined in inst.h as cbcond0_op & cbcond1_op are
actually defined in the MIPS base instruction set manuals as pop10 &
pop30 respectively. Rename them as such, for consistency with the
documentation.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 1b492600068d5fbd033196ce2bdb28735a23747e)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:31 -08:00
Paul Burton
b1529b8d20 UPSTREAM: MIPS: inst.h: Rename b{eq,ne}zcji[al]c_op to pop{6,7}6_op
The opcodes currently defined in inst.h as beqzcjic_op & bnezcjialc_op
are actually defined in the MIPS base instruction set manuals as pop66 &
pop76 respectively. Rename them as such, for consistency with the
documentation.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 1c66b79bb3b11942a98085fd89295cf6cddae41a)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:31 -08:00
Paul Burton
f67d2acc25 UPSTREAM: MIPS: math-emu: Fix m{add,sub}.s shifts
The code in _sp_maddf (formerly ieee754sp_madd) appears to have been
copied verbatim from ieee754sp_add, and although it's adding the
unpacked "r" & "z" floats it kept using macros that operate on "x" &
"y". This led to the addition being carried out incorrectly on some
mismash of the product, accumulator & multiplicand fields. Typically
this would lead to the assertions "ze == re" & "ze <= SP_EMAX" failing
since ze & re hadn't been operated upon.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Fixes: e24c3bec3e ("MIPS: math-emu: Add support for the MIPS R6 MADDF FPU instruction")
Cc: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13159/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit db57f29d50683afd75c7f8b9908af7669837c3a9)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:30 -08:00
Paul Burton
d3154ef703 UPSTREAM: MIPS: inst: Declare fsel_op for sel.fmt instruction
Declare the opcode for the MIPSr6 sel.fmt instruction, as fsel_op in
order to match other FP op names.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13152/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit b6d5c4eda7a771e72b3640500e026d72c4f64419)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:30 -08:00
Paul Burton
478f521caf UPSTREAM: MIPS: math-emu: Fix code indentation
A line incrementing the re variable was indented a level too deep in
ieee754dp_mul, making the code unclear to read. Fix the indentation.
This appears to have been copied verbatim along with the rest of the
multiplication code to ieee754dp_maddf, now _dp_maddf, too so fix the
indentation there too.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13158/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 5c18c936b52ae80db5737849e11f436e79b84b2d)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:30 -08:00
Paul Burton
fb2a789d16 UPSTREAM: MIPS: math-emu: Fix bit-width in ieee754dp_{mul, maddf, msubf} comments
A comment in ieee754dp_mul indicates that the code is about to perform a
32b x 32b multiplication & keep the high 32b of the result. It appears
this was copied from the single-precision multiplication code, since the
code actually goes on to perform a 64b x 64b multiplication & keep the
high 64b of the result. Fix the comment to indicate 64b.

It appears also that this comment was copied verbatim along with the
rest of the multiplication code into ieee754dp_maddf, which has since
been renamed _dp_maddf. Fix the same issue there.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13157/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 95bff2410cdccfe2cf4b99f4e86165956767740e)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:30 -08:00
Paul Burton
663009749f UPSTREAM: MIPS: math-emu: Add z argument macros
Introduce macros for handling the "z" argument to maddf & msubf, making
its handling consistent with that of the "x" & "y" arguments rather than
open-coding equivalents.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13156/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit e2d11e1a8398b7447d337add50521a5abc6267fd)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:30 -08:00
Paul Burton
8c50090eae UPSTREAM: MIPS: math-emu: Unify ieee754dp_m{add,sub}f
The code for emulating MIPSr6 madd.d & msub.d instructions has
previously been implemented as 2 different functions, namely
ieee754dp_maddf & ieee754dp_msubf. The difference in behaviour of these
2 instructions is merely the sign of the product, so we can easily share
the code implementing them. Do this for the double precision variant,
removing the original ieee754dp_msubf in favor of reusing the code from
ieee754dp_maddf.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13155/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit d728f6709bcc49c98097485e3561f1faaf52b4f3)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:30 -08:00
Paul Burton
e6ba769958 UPSTREAM: MIPS: math-emu: Unify ieee754sp_m{add,sub}f
The code for emulating MIPSr6 madd.s & msub.s instructions has
previously been implemented as 2 different functions, namely
ieee754sp_maddf & ieee754sp_msubf. The difference in behaviour of these
2 instructions is merely the sign of the product, so we can easily share
the code implementing them. Do this for the single precision variant,
removing the original ieee754sp_msubf in favor of reusing the code from
ieee754sp_maddf.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13154/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 6162051e87f6ea785cb51ad99bdcf8eb0bd9cb07)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:30 -08:00
Paul Burton
476f2f0a48 UPSTREAM: MIPS: math-emu: Emulate MIPSr6 sel.fmt instruction
Add support for emulating the MIPSr6 sel.fmt instruction, which was
previously missing from the FPU emulation code. This instruction selects
its result from 2 possible source registers, based upon bit 0 of the
destination register, and is valid only for S (single) & D (double) data
types.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13153/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 4b820d95dc53c15e6e727da964430a3ed60e05ef)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:30 -08:00
Paul Burton
b61e67de1a UPSTREAM: MIPS: math-emu: Fix BC1{EQ,NE}Z emulation
The conditions for branching when emulating the BC1EQZ & BC1NEZ
instructions were backwards, leading to each of those instructions being
treated as the other. Fix this by reversing the conditions, and clear up
the code a little for readability & checkpatch.

Fixes: c909ca718e ("MIPS: math-emu: Emulate missing BC1{EQ,NE}Z instructions")
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13150/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 93583e178ebfdd2fadf950eef1547f305cac12ca)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:30 -08:00
Maciej W. Rozycki
9a89fca3bb UPSTREAM: MIPS: math-emu: Always propagate sNaN payload in quieting
Propagate sNaN payload in quieting in the legacy-NaN mode as well.  If
clearing the quiet bit would produce infinity, then set the next lower
trailing significand field bit, matching the SB-1 and BMIPS5000 hardware
implementations.  Some other MIPS FPU hardware implementations do
produce the default qNaN bit pattern instead.

This reverts some changes made for semantics preservation with commit
dc3ddf42 [MIPS: math-emu: Update sNaN quieting handlers], consequently
bringing back most of the semantics from before commit fdffbafb [Lots of
FPU bug fixes from Kjeld Borch Egevang.], except from the qNaN produced
in the infinity case.  Previously the default qNaN bit pattern was
produced in that case.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11483/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit acd9e20cd9d0e6af5680e1870a966d8082a1130a)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:30 -08:00
Adam Buchbinder
0c23219c3a UPSTREAM: MIPS: Fix misspellings in comments.
Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: trivial@kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12617/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 92a76f6d8545efc67f03278009e9a828bdad3419)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:30 -08:00
Maciej W. Rozycki
bb61ba2136 UPSTREAM: MIPS: math-emu: Add IEEE Std 754-2008 NaN encoding emulation
Implement IEEE Std 754-2008 NaN encoding wired to the state of the
FCSR.NAN2008 bit.  Make the interpretation of the quiet bit in NaN data
as follows:

* in the legacy mode originally defined by the MIPS architecture the
  value of 1 denotes an sNaN whereas the value of 0 denotes a qNaN,

* in the 2008 mode introduced with revision 5 of the MIPS architecture
  the value of 0 denotes an sNaN whereas the value of 1 denotes a qNaN,
  following the definition of the preferred NaN encoding introduced with
  IEEE Std 754-2008.

In the 2008 mode, following the requirement of the said standard, quiet
an sNaN where needed by setting the quiet bit to 1 and leaving all the
NaN payload bits unchanged.

Update format conversion operations according to the rules set by IEEE
Std 754-2008 and the MIPS architecture.  Specifically:

* propagate NaN payload bits through conversions between floating-point
  formats such that as much information as possible is preserved and
  specifically a conversion from a narrower format to a wider format and
  then back to the original format does not change a qNaN payload in any
  way,

* conversions from a floating-point to an integer format where the
  source is a NaN, infinity or a value that would convert to an integer
  outside the range of the result format produce, under the default
  exception handling, the respective values defined by the MIPS
  architecture.

In full FPU emulation set the FIR.HAS2008 bit to 1, however do not make
any further FCSR bits writable.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11477/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 90d53a91fbd0c5a0882c29fa4279a3d2d700c76d)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:30 -08:00
Maciej W. Rozycki
71b31a91e3 UPSTREAM: MIPS: math-emu: Add IEEE Std 754-2008 ABS.fmt and NEG.fmt emulation
Implement IEEE Std 754-2008 non-arithmetic ABS.fmt and NEG.fmt emulation
wired to the state of the FCSR.ABS2008 bit.  In the non-arithmetic mode
the sign bit is altered according to the operation requested regardless
of the datum encoded in the input operand, no other bits are changed,
the resulting bit pattern is written to the output operand and no
exception is ever signalled.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11476/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 198f70589e3c0f0f50da646152443787e959228f)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:30 -08:00
Paul Burton
b38614bbdf UPSTREAM: MIPS: non-exec stack & heap when non-exec PT_GNU_STACK is present
The stack and heap have both been executable by default on MIPS until
now. This patch changes the default to be non-executable, but only for
ELF binaries with a non-executable PT_GNU_STACK header present. This
does apply to both the heap & the stack, despite the name PT_GNU_STACK,
and this matches the behaviour of other architectures like ARM & x86.

Current MIPS toolchains do not produce the PT_GNU_STACK header, which
means that we can rely upon this patch not changing the behaviour of
existing binaries. The new default will only take effect for newly
compiled binaries once toolchains are updated to support PT_GNU_STACK,
and since those binaries are newly compiled they can be compiled
expecting the change in default behaviour. Again this matches the way in
which the ARM & x86 architectures handled their implementations of
non-executable memory.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: Maciej Rozycki <maciej.rozycki@imgtec.com>
Cc: Faraz Shahbazker <faraz.shahbazker@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: Matthew Fortune <matthew.fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13765/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 1a770b85c1f1c1ee37afd7cef5237ffc4c970f04)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:30 -08:00
Maciej W. Rozycki
39dd84faa5 UPSTREAM: MIPS: Add IEEE Std 754 conformance mode selection
Add an `ieee754=' kernel parameter to control IEEE Std 754 conformance
mode.

Use separate flags copied from the respective CPU feature flags, and
adjusted according to the conformance mode selected, to make binaries
requesting individual NaN encoding modes accepted or rejected as needed.
Update the initial setting for FCSR and, in the full FPU emulation mode,
its read-only mask accordingly.  Accept the mode selection requested for
legacy processors as well.

As with the EF_MIPS_NAN2008 ELF file header flag adjust both ABS2008 and
NAN2008 bits at the same time, to match the choice made for hardware
currently implemented.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11481/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 503943e0e52bd3fbf014aa1d838ced37adb43121)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:30 -08:00
Maciej W. Rozycki
5dd3c3a431 UPSTREAM: MIPS: Determine the presence of IEEE Std 754-2008 features
Determine the presence of and the amount of control available over IEEE
Std 754-2008 features.

In the case of a hardware FPU being used examine the FIR register for
the presence of the HAS2008 bit and then the FCSR register for the
writability of the ABS2008 and NAN2008 bits and the hardwired state of
each of these bits if read-only.  Update the initial FCSR contents used
for threads and the FCSR writability mask accordingly.

For full FPU emulation and MIPS32 or MIPS64 processors make the FCSR
ABS2008 and NAN2008 bits writable.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11480/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 93adeaf6dadcaed943a51ad9ea2d77e24e6d70a7)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:30 -08:00
Maciej W. Rozycki
d73ca92398 UPSTREAM: MIPS: Define the legacy-NaN and 2008-NaN features
Allocate CPU option bits and define macros for the legacy-NaN and
2008-NaN IEEE Std 754 MIPS architecture features.  Unconditionally mark
the legacy-NaN feature as present across hardware and emulated
floating-point configurations.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11475/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 9519ef37a4a4e9c3c2d7d89ecbecfaf3c839208a)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:30 -08:00
Maciej W. Rozycki
43517cec9f UPSTREAM: MIPS: ELF: Interpret the NAN2008 file header flag
Handle the EF_MIPS_NAN2008 ELF file header flag and refuse execution
where there is no support in the FPU for the NaN encoding mode requested
by a binary invoked.  Ensure that the setting of the bit in the binary
matches one in any intepreter used.  Set the thread's initial FCSR
contents according to the value of the EF_MIPS_NAN2008.

Set the values of the FCSR ABS2008 and NAN2008 bits both to the same
value if possible, to take the approach taken with existing FPU hardware
into account.  As of now all implementations have both bits hardwired to
the same value, that is both are fixed at 0 or both are fixed at 1, even
though the architecture allows for implementations where the amount of
control implemented with each of these two individual bits is
independent of each other.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11479/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 2b5e869ecfcb3112f7e1267cb0328f3ff6d49b18)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:29 -08:00
Maciej W. Rozycki
380f74966e UPSTREAM: ELF: Also pass any interpreter's file header to `arch_check_elf'
Also pass any interpreter's file header to `arch_check_elf' so that any
architecture handler can have a look at it if needed.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11478/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit eb4bc076ff94b82fce04f6db061de597f71bd129)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:29 -08:00
Maciej W. Rozycki
18e152e051 UPSTREAM: MIPS: Use a union to access the ELF file header
Rewrite `arch_elf_pt_proc' and `arch_check_elf' using a union to access
the ELF file header.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11474/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 2ed02dd415aee71a8bf4c621a9bd65c256642b96)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:29 -08:00
Paul Burton
30bee7f938 UPSTREAM: MIPS: Fix delay slot emulation count in debugfs
Commit 432c6bacbd0c ("MIPS: Use per-mm page to execute branch delay slot
instructions") accidentally removed use of the MIPS_FPU_EMU_INC_STATS
macro from do_dsemulret, leading to the ds_emul file in debugfs always
returning zero even though we perform delay slot emulations.

Fix this by re-adding the use of the MIPS_FPU_EMU_INC_STATS macro.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Fixes: 432c6bacbd0c ("MIPS: Use per-mm page to execute branch delay slot instructions")
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14301/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 116e7111c8e3cc65ceef9664741bd593483e9517)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:29 -08:00
Jiri Slaby
af22cc785f BACKPORT: exit_thread: accept a task parameter to be exited
We need to call exit_thread from copy_process in a fail path.  So make it
accept task_struct as a parameter.

[v2]
* s390: exit_thread_runtime_instr doesn't make sense to be called for
  non-current tasks.
* arm: fix the comment in vfp_thread_copy
* change 'me' to 'tsk' for task_struct
* now we can change only archs that actually have exit_thread

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: David Howells <dhowells@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

(cherry picked from commit e64646946ed32902fd597fa6e514b1da84642de3)

Conflicts:
	arch/s390/kernel/process.c
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:29 -08:00
Jiri Slaby
c16fb87374 UPSTREAM: mn10300: let exit_fpu accept a task
We need to call exit_thread from copy_process in a fail path.  Since
exit_thread on mn10300 calls exit_thread_runtime_instr, make it accept
task_struct as a parameter now.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: David Howells <dhowells@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 2ec656eb4054ce55e6d453b8614ef9669e84c542)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:29 -08:00
Paul Burton
c9cd1837ca UPSTREAM: MIPS: Use per-mm page to execute branch delay slot instructions
In some cases the kernel needs to execute an instruction from the delay
slot of an emulated branch instruction. These cases include:

  - Emulated floating point branch instructions (bc1[ft]l?) for systems
    which don't include an FPU, or upon which the kernel is run with the
    "nofpu" parameter.

  - MIPSr6 systems running binaries targeting older revisions of the
    architecture, which may include branch instructions whose encodings
    are no longer valid in MIPSr6.

Executing instructions from such delay slots is done by writing the
instruction to memory followed by a trap, as part of an "emuframe", and
executing it. This avoids the requirement of an emulator for the entire
MIPS instruction set. Prior to this patch such emuframes are written to
the user stack and executed from there.

This patch moves FP branch delay emuframes off of the user stack and
into a per-mm page. Allocating a page per-mm leaves userland with access
to only what it had access to previously, and compared to other
solutions is relatively simple.

When a thread requires a delay slot emulation, it is allocated a frame.
A thread may only have one frame allocated at any one time, since it may
only ever be executing one instruction at any one time. In order to
ensure that we can free up allocated frame later, its index is recorded
in struct thread_struct. In the typical case, after executing the delay
slot instruction we'll execute a break instruction with the BRK_MEMU
code. This traps back to the kernel & leads to a call to do_dsemulret
which frees the allocated frame & moves the user PC back to the
instruction that would have executed following the emulated branch.
In some cases the delay slot instruction may be invalid, such as a
branch, or may trigger an exception. In these cases the BRK_MEMU break
instruction will not be hit. In order to ensure that frames are freed
this patch introduces dsemul_thread_cleanup() and calls it to free any
allocated frame upon thread exit. If the instruction generated an
exception & leads to a signal being delivered to the thread, or indeed
if a signal simply happens to be delivered to the thread whilst it is
executing from the struct emuframe, then we need to take care to exit
the frame appropriately. This is done by either rolling back the user PC
to the branch or advancing it to the continuation PC prior to signal
delivery, using dsemul_thread_rollback(). If this were not done then a
sigreturn would return to the struct emuframe, and if that frame had
meanwhile been used in response to an emulated branch instruction within
the signal handler then we would execute the wrong user code.

Whilst a user could theoretically place something like a compact branch
to self in a delay slot and cause their thread to become stuck in an
infinite loop with the frame never being deallocated, this would:

  - Only affect the users single process.

  - Be architecturally invalid since there would be a branch in the
    delay slot, which is forbidden.

  - Be extremely unlikely to happen by mistake, and provide a program
    with no more ability to harm the system than a simple infinite loop
    would.

If a thread requires a delay slot emulation & no frame is available to
it (ie. the process has enough other threads that all frames are
currently in use) then the thread joins a waitqueue. It will sleep until
a frame is freed by another thread in the process.

Since we now know whether a thread has an allocated frame due to our
tracking of its index, the cookie field of struct emuframe is removed as
we can be more certain whether we have a valid frame. Since a thread may
only ever have a single frame at any given time, the epc field of struct
emuframe is also removed & the PC to continue from is instead stored in
struct thread_struct. Together these changes simplify & shrink struct
emuframe somewhat, allowing twice as many frames to fit into the page
allocated for them.

The primary benefit of this patch is that we are now free to mark the
user stack non-executable where that is possible.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: Maciej Rozycki <maciej.rozycki@imgtec.com>
Cc: Faraz Shahbazker <faraz.shahbazker@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: Matthew Fortune <matthew.fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13764/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 432c6bacbd0c16ec210c43da411ccc3855c4c010)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:29 -08:00
Heiko Carstens
cc261c3729 BACKPORT: s390: get rid of exit_thread()
exit_thread() is empty now. Therefore remove it and get rid of a
pointless branch.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
(cherry picked from commit 59a19ea9a0b3b0ee69887b6a5015aee3a3c7e527)

Conflicts:
	arch/s390/Kconfig
	arch/s390/kernel/process.c
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:29 -08:00
Jiri Slaby
3ebefa7840 BACKPORT: exit_thread: remove empty bodies
Define HAVE_EXIT_THREAD for archs which want to do something in
exit_thread. For others, let's define exit_thread as an empty inline.

This is a cleanup before we change the prototype of exit_thread to
accept a task parameter.

[akpm@linux-foundation.org: fix mips]
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: David Howells <dhowells@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

(cherry picked from commit 5f56a5dfdb9bcb3bca03df59980d4d2f012cbb53)

Conflicts:
	arch/powerpc/kernel/process.c
	arch/xtensa/Kconfig
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:29 -08:00
Ralf Baechle
5ea4150e17 UPSTREAM: MIPS: Make flush_thread
Avoids function calls to an empty function.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 04cc89d120f94131de89a6e20da27016db4782ce)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:29 -08:00
James Hogan
1e9d84070a UPSTREAM: MIPS: Properly disable FPU in start_thread()
start_thread() (called for execve(2)) clears the TIF_USEDFPU flag
without atomically disabling the FPU. With a preemptive kernel, an
unfortunately timed preemption after this could result in another
task (or KVM guest) being scheduled in with the FPU still enabled, since
lose_fpu_inatomic() only turns it off if TIF_USEDFPU is set.

Use lose_fpu(0) instead of the separate FPU / MSA management, which
should do the right thing (drop FPU properly and atomically without
saving state) and will be more future proof.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12302/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 76e5846d3bdf59eb1010d5607003da2dc3910bb1)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:29 -08:00
David Daney
cb7c7f371e UPSTREAM: MIPS: Select CONFIG_HANDLE_DOMAIN_IRQ and make it work.
Per the subject, always select HANDLE_DOMAIN_IRQ, and implement
set_irq_regs() so that it actually works.

Signed-off-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12496/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 1d2753a66acbb101a0ec495cd13b9031ac1b171f)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:29 -08:00
Andrea Gelmini
afcd2b8978 UPSTREAM: MIPS: math-emu: Fix typo
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Cc: macro@imgtec.com
Cc: trivial@kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13333/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit e7e3346cc64fff306694bdc41908283d195339c1)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:29 -08:00
Maciej W. Rozycki
883f4325f6 UPSTREAM: MIPS: math-emu: dsemul: Remove an unused bit in ADDIUPC emulation
Avoid a reader's confusion, as the calculation is correct either way.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12283/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 036aff91c30a6f15d5bf25f22827abc26b6d06c1)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-02-05 08:58:29 -08:00