linux-stable.git/arch/mips/kernel/traps.c, branch linux-4.7.y

MIPS: MSA: Fix a link error on `_init_msa_upper' with older GCC

2016-05-17T09:02:45+00:00

Fix a build regression from commit c9017757c532 ("MIPS: init upper 64b
of vector registers when MSA is first used"):

arch/mips/built-in.o: In function `enable_restore_fp_context':
traps.c:(.text+0xbb90): undefined reference to `_init_msa_upper'
traps.c:(.text+0xbb90): relocation truncated to fit: R_MIPS_26 against `_init_msa_upper'
traps.c:(.text+0xbef0): undefined reference to `_init_msa_upper'
traps.c:(.text+0xbef0): relocation truncated to fit: R_MIPS_26 against `_init_msa_upper'

to !CONFIG_CPU_HAS_MSA configurations with older GCC versions, which are
unable to figure out that calls to `_init_msa_upper' are indeed dead.
Of the many ways to tackle this failure choose the approach we have
already taken in `thread_msa_context_live'.

[ralf@linux-mips.org: Drop patch segment to junk file.]

Signed-off-by: Maciej W. Rozycki 
Cc: stable@vger.kernel.org # v3.16+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13271/
Signed-off-by: Ralf Baechle

MIPS: Retrieve ASID masks using function accepting struct cpuinfo_mips

2016-05-13T12:02:20+00:00

In preparation for supporting variable ASID masks, retrieve ASID masks
using functions in asm/cpu-info.h which accept struct cpuinfo_mips. This
will allow those functions to determine the ASID mask based upon the CPU
in a later patch. This also allows for the r3k & r8k cases to be handled
in Kconfig, which is arguably cleaner than the previous #ifdefs.

Signed-off-by: Paul Burton 
Signed-off-by: James Hogan 
Cc: Paolo Bonzini 
Cc: Radim Krčmář 
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13210/
Signed-off-by: Ralf Baechle

MIPS: traps: remove unused variable

2016-05-13T12:02:15+00:00

flags is indeed unused.

Signed-off-by: Tony Wu 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11699/
Signed-off-by: Ralf Baechle

MIPS: Loongson: Add Loongson-3A R2 basic support

2016-05-13T12:02:14+00:00

Loongson-3 CPU family:

Code-name       Brand-name       PRId
Loongson-3A R1  Loongson-3A1000  0x6305
Loongson-3A R2  Loongson-3A2000  0x6308
Loongson-3B R1  Loongson-3B1000  0x6306
Loongson-3B R2  Loongson-3B1500  0x6307

Features of R2 revision of Loongson-3A:

  - Primary cache includes I-Cache, D-Cache and V-Cache (Victim Cache).
  - I-Cache, D-Cache and V-Cache are 16-way set-associative, linesize is
     64 bytes.
  - 64 entries of VTLB (classic TLB), 1024 entries of FTLB (8-way
     set-associative).
  - Supports DSP/DSPv2 instructions, UserLocal register and Read-Inhibit/
     Execute-Inhibit.

[ralf@linux-mips.org: Resolved merge conflicts.]

Signed-off-by: Huacai Chen 
Cc: Aurelien Jarno 
Cc: Steven J . Hill 
Cc: Fuxin Zhang 
Cc: Zhangjin Wu 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12751/
Patchwork: https://patchwork.linux-mips.org/patch/13136/
Signed-off-by: Ralf Baechle

MIPS: Add and use CAUSEF_WP definition

2016-05-13T12:02:13+00:00

do_watch() clears bit 22 of cause without using a CAUSEF_* definition
from mipsregs.h. Add a definition for this bit (CAUSEF_WP) and make use
of it. Also use clear_c0_cause() instead of manual read/modify/write.

Signed-off-by: James Hogan 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12728/
Signed-off-by: Ralf Baechle

MIPS: Add P6600 cases to CPU switch statements

2016-05-13T12:01:52+00:00

Add cases supporting the P6600 CPU to various switch statements in
core MIPS kernel code that define behaviour dependent upon the CPU.

Signed-off-by: Paul Burton 
Cc: Maciej W. Rozycki 
Cc: Peter Zijlstra 
Cc: Joshua Kinard 
Cc: Andrzej Hajda 
Cc: Leonid Yegoshin 
Cc: Paul Gortmaker 
Cc: James Hogan 
Cc: Arnaldo Carvalho de Melo 
Cc: Ingo Molnar 
Cc: Petri Gynther 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12343/
Signed-off-by: Ralf Baechle

MIPS: traps: Make sure secondary cores have a sane ebase register

2016-05-13T12:01:48+00:00

We shouldn't trust that the secondary cores will have a sane ebase register
(either from the bootloader or during the hardware design phase) so use the
ebase address as calculated by the boot CPU.

Signed-off-by: Markos Chandras 
Signed-off-by: Paul Burton 
Cc: linux-mips@linux-mips.org
Cc: Leonid Yegoshin 
Cc: Maciej W. Rozycki 
Cc: James Hogan 
Cc: Petri Gynther 
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12328/
Signed-off-by: Ralf Baechle

MIPS: panic immediately when panic_on_oops

2016-05-13T12:01:44+00:00

MIPS wants to sleep 5 seconds before panicking when panic_on_oops is set,
with no apparent reason. Remove this feature, since some users may want
their systems to fail as quickly as possible.

Users who want to delay reboot after panic can use PANIC_TIMEOUT.

Signed-off-by: Aaro Koskinen 
Cc: James E.J. Bottomley 
Cc: Helge Deller 
Cc: linux-mips@linux-mips.org
Cc: linux-parisc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12845/
Signed-off-by: Ralf Baechle

MIPS: Avoid using unwind_stack() with usermode

2016-05-09T10:00:02+00:00

When showing backtraces in response to traps, for example crashes and
address errors (usually unaligned accesses) when they are set in debugfs
to be reported, unwind_stack will be used if the PC was in the kernel
text address range. However since EVA it is possible for user and kernel
address ranges to overlap, and even without EVA userland can still
trigger an address error by jumping to a KSeg0 address.

Adjust the check to also ensure that it was running in kernel mode. I
don't believe any harm can come of this problem, since unwind_stack() is
sufficiently defensive, however it is only meant for unwinding kernel
code, so to be correct it should use the raw backtracing instead.

Signed-off-by: James Hogan 
Reviewed-by: Leonid Yegoshin 
Cc: linux-mips@linux-mips.org
Cc:  # 3.15+
Patchwork: https://patchwork.linux-mips.org/patch/11701/
Signed-off-by: Ralf Baechle 
(cherry picked from commit d2941a975ac745c607dfb590e92bb30bc352dad9)

MIPS: traps.c: Verify the ISA for microMIPS RDHWR emulation

2016-04-04T13:25:34+00:00

Make sure it's the microMIPS rather than MIPS16 ISA before emulating
microMIPS RDHWR.  Mostly needed as an optimisation for configurations
where `cpu_has_mmips' is hardcoded to 0 and also a good measure in case
we add further microMIPS instructions to emulate in the future, as the
corresponding MIPS16 encoding is ADDIUSP, not supposed to trap.

Signed-off-by: Maciej W. Rozycki 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12282/
Signed-off-by: Ralf Baechle