Commit graph

2067 commits

Author SHA1 Message Date
James Hogan a1ec0e1883 MIPS: perf: Allow sharing IRQ with timer
When requesting the performance counter overflow interrupt, pass flags
which are compatible with the cevt-r4k driver, in particular
IRQF_SHARED so that the two handlers can share the same IRQ. This is
possible since release 2 of the architecture where there are separate
pending interrupt bits for the timer interrupt and the performance
counter interrupt.

This will be necessary since the FDC interrupt can also be arbitrarily
routed to a CPU interrupt, possibly sharing with the timer, the
performance counters, or both, and it isn't scalable to have all the
handlers able to call other handlers that may be on the same IRQ line.

Shared handlers must also have a unique device pointer so they can be
individually removed, so &mipspmu is now passed in for that instead of
NULL.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/9129/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-31 12:04:12 +02:00
Ralf Baechle f0c5b8944b MIPS: cevt-r4k: Cleanup c0_compare_interrupt.
The attempt to get gcc to generate best possible code turned
c0_compare_interrupt() into a bit of Italian pasta code.  Tweak for
sanity.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-31 12:04:12 +02:00
James Hogan 7dfe819803 MIPS: cevt-r4k: Make interrupt handler shared
Make the cevt-r4k interrupt handler shared so that other interrupt
handlers (specifically the performance counter overflow handler and fast
debug channel interrupt handler) can share the same interrupt line.

This simply imvolves returning IRQ_NONE when no timer interrupt has been
handled to allow other handlers to run, and passing IRQF_SHARED when
setting up the IRQ handler so that other handlers (with compatible
flags) can be registered.

Signed-off-by: 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/9128/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-31 12:04:12 +02:00
James Hogan 7eca5b1460 MIPS: Remove redundant IPTI==IPPCI logic
The situation where the timer interrupt is on the same line as the
performance counter interrupt is handled in per_cpu_trap_init() by
setting cp0_perfcount_irq to -1, so there is no need to duplicate the
logic conditional upon cp0_perfcount_irq >= 0 in perf
(init_hw_perf_events()) and oprofile (mipsxx_init()).

Signed-off-by: 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/9125/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-31 12:04:12 +02:00
James Hogan 3ba5040af0 MIPS: cevt-r4k: Use CAUSEF_TI, CAUSEF_PCI constants
Use CAUSEF_TI and CAUSEF_PCI constants from asm/mipsregs.h rather than
the magic values (1 << 30) and (1 << 26).

Signed-off-by: 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/9124/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-31 12:04:12 +02:00
James Hogan 19971c0bcb MIPS: cevt-r4k: Move handle_perf_irq() out of header
Long ago, commit 8531a35e5e ("[MIPS] SMTC: Fix SMTC dyntick support.")
moved handle_perf_irq() out of cevt-r4k.c into a header so it could be
shared with cevt-smtc.c.

Slightly less long ago, commit b633648c5a ("MIPS: MT: Remove SMTC
support") removed all traces of SMTC support, including cevt-smtc.c,
leaving cevt-r4k.c once again the sole user of handle_perf_irq(),
therefore move it back into cevt-r4k.c from the header.

Signed-off-by: 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/9123/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-31 12:04:12 +02:00
James Hogan 539cb89fbd MIPS: KVM: Add base guest MSA support
Add base code for supporting the MIPS SIMD Architecture (MSA) in MIPS
KVM guests. MSA cannot yet be enabled in the guest, we're just laying
the groundwork.

As with the FPU, whether the guest's MSA context is loaded is stored in
another bit in the fpu_inuse vcpu member. This allows MSA to be disabled
when the guest disables it, but keeping the MSA context loaded so it
doesn't have to be reloaded if the guest re-enables it.

New assembly code is added for saving and restoring the MSA context,
restoring only the upper half of the MSA context (for if the FPU context
is already loaded) and for saving/clearing and restoring MSACSR (which
can itself cause an MSA FP exception depending on the value). The MSACSR
is restored before returning to the guest if MSA is already enabled, and
the existing FP exception die notifier is extended to catch the possible
MSA FP exception and step over the ctcmsa instruction.

The helper function kvm_own_msa() is added to enable MSA and restore
the MSA context if it isn't already loaded, which will be used in a
later patch when the guest attempts to use MSA for the first time and
triggers an MSA disabled exception.

The existing FPU helpers are extended to handle MSA. kvm_lose_fpu()
saves the full MSA context if it is loaded (which includes the FPU
context) and both kvm_lose_fpu() and kvm_drop_fpu() disable MSA.

kvm_own_fpu() also needs to lose any MSA context if FR=0, since there
would be a risk of getting reserved instruction exceptions if CU1 is
enabled and we later try and save the MSA context. We shouldn't usually
hit this case since it will be handled when emulating CU1 changes,
however there's nothing to stop the guest modifying the Status register
directly via the comm page, which will cause this case to get hit.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
2015-03-27 21:25:19 +00:00
James Hogan 98e91b8457 MIPS: KVM: Add base guest FPU support
Add base code for supporting FPU in MIPS KVM guests. The FPU cannot yet
be enabled in the guest, we're just laying the groundwork.

Whether the guest's FPU context is loaded is stored in a bit in the
fpu_inuse vcpu member. This allows the FPU to be disabled when the guest
disables it, but keeping the FPU context loaded so it doesn't have to be
reloaded if the guest re-enables it.

An fpu_enabled vcpu member stores whether userland has enabled the FPU
capability (which will be wired up in a later patch).

New assembly code is added for saving and restoring the FPU context, and
for saving/clearing and restoring FCSR (which can itself cause an FP
exception depending on the value). The FCSR is restored before returning
to the guest if the FPU is already enabled, and a die notifier is
registered to catch the possible FP exception and step over the ctc1
instruction.

The helper function kvm_lose_fpu() is added to save FPU context and
disable the FPU, which is used when saving hardware state before a
context switch or KVM exit (the vcpu_get_regs() callback).

The helper function kvm_own_fpu() is added to enable the FPU and restore
the FPU context if it isn't already loaded, which will be used in a
later patch when the guest attempts to use the FPU for the first time
and triggers a co-processor unusable exception.

The helper function kvm_drop_fpu() is added to discard the FPU context
and disable the FPU, which will be used in a later patch when the FPU
state will become architecturally UNPREDICTABLE (change of FR mode) to
force a reload of [stale] context in the new FR mode.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
2015-03-27 21:25:14 +00:00
James Hogan 64bedffe49 MIPS: Clear [MSA]FPE CSR.Cause after notify_die()
When handling floating point exceptions (FPEs) and MSA FPEs the Cause
bits of the appropriate control and status register (FCSR for FPEs and
MSACSR for MSA FPEs) are read and cleared before enabling interrupts,
presumably so that it doesn't have to go through the pain of restoring
those bits if the process is pre-empted, since writing those bits would
cause another immediate exception while still in the kernel.

The bits aren't normally ever restored again, since userland never
expects to see them set.

However for virtualisation it is necessary for the kernel to be able to
restore these Cause bits, as the guest may have been interrupted in an
FP exception handler but before it could read the Cause bits. This can
be done by registering a die notifier, to get notified of the exception
when such a value is restored, and if the PC was at the instruction
which is used to restore the guest state, the handler can step over it
and continue execution. The Cause bits can then remain set without
causing further exceptions.

For this to work safely a few changes are made:
- __build_clear_fpe and __build_clear_msa_fpe no longer clear the Cause
  bits, and now return from exception level with interrupts disabled
  instead of enabled.
- do_fpe() now clears the Cause bits and enables interrupts after
  notify_die() is called, so that the notifier can chose to return from
  exception without this happening.
- do_msa_fpe() acts similarly, but now actually makes use of the second
  argument (msacsr) and calls notify_die() with the new DIE_MSAFP,
  allowing die notifiers to be informed of MSA FPEs too.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
2015-03-27 21:25:06 +00:00
James Hogan 466aec5f29 Revert "MIPS: Don't assume 64-bit FP registers for context switch"
This reverts commit 02987633df.

The basic premise of the patch was incorrect since MSA context
(including FP state) is saved using st.d which stores two consecutive
64-bit words in memory rather than a single 128-bit word. This means
that even with big endian MSA, the FP state is still in the first 64-bit
word.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9168/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-27 19:42:48 +01:00
Paul Burton ac9ad83bc3 MIPS: prevent FP context set via ptrace being discarded
If a ptracee has not used the FPU and the ptracer sets its FP context
using PTRACE_POKEUSR, PTRACE_SETFPREGS or PTRACE_SETREGSET then that
context will be discarded upon either the ptracee using the FPU or a
further write to the context via ptrace. Prevent this loss by recording
that the task has "used" math once its FP context has been written to.
The context initialisation code that was present for the PTRACE_POKEUSR
case is reused for the other 2 cases to provide consistent behaviour
for the different ptrace requests.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9166/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-27 19:42:47 +01:00
Paul Burton ad70c13a93 MIPS: Ensure FCSR cause bits are clear after invoking FPU emulator
When running the emulator to handle an instruction that raised an FP
unimplemented operation exception, the FCSR cause bits were being
cleared. This is done to ensure that the kernel does not take an FP
exception when later restoring FP context to registers. However, this
was not being done when the emulator is invoked in response to a
coprocessor unusable exception. This happens in 2 cases:

  - There is no FPU present in the system. In this case things were
    OK, since the FP context is never restored to hardware registers
    and thus no FP exception may be raised when restoring FCSR.

  - The FPU could not be configured to the mode required by the task.
    In this case it would be possible for the emulator to set cause
    bits which are later restored to hardware if the task migrates
    to a CPU whose associated FPU does support its mode requirements,
    or if the tasks FP mode requirements change.

Consistently clear the cause bits after invoking the emulator, by moving
the clearing to process_fpemu_return and ensuring this is always called
before the tasks FP context is restored. This will make it easier to
catch further paths invoking the emulator in future, as will be
introduced in further patches.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9165/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-27 19:42:46 +01:00
Paul Burton 091be550a7 MIPS: clear MSACSR cause bits when handling MSA FP exception
Much like for traditional scalar FP exceptions, the cause bits in the
MSACSR register need to be cleared following an MSA FP exception.
Without doing so the exception will simply be raised again whenever
the kernel restores MSACSR from a tasks saved context, leading to
undesirable spurious exceptions. Clear the cause bits from the
handle_msa_fpe function, mirroring the way handle_fpe clears the
cause bits in FCSR.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9164/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-27 19:42:45 +01:00
Paul Burton 631afc65e8 MIPS: Push .set mips64r* into the functions needing it
The {save,restore}_fp_context{,32} functions require that the assembler
allows the use of sdc instructions on any FP register, and this is
acomplished by setting the arch to mips64r2 or mips64r6
(using MIPS_ISA_ARCH_LEVEL_RAW).

However this has the effect of enabling the assembler to use mips64
instructions in the expansion of pseudo-instructions. This was done in
the (now-reverted) commit eec43a224c "MIPS: Save/restore MSA context
around signals" which led to my mistakenly believing that there was an
assembler bug, when in reality the assembler was just emitting mips64
instructions. Avoid the issue for future commits which will add code to
r4k_fpu.S by pushing the .set MIPS_ISA_ARCH_LEVEL_RAW directives into
the functions that require it, and remove the spurious assertion
declaring the assembler bug.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
[james.hogan@imgtec.com: Rebase on v4.0-rc1 and reword commit message to
 reflect use of MIPS_ISA_ARCH_LEVEL_RAW]
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9612/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-27 19:42:42 +01:00
Alex Dowad e2c5aaa5fd mips: copy_thread(): rename 'arg' argument to 'kthread_arg'
The 'arg' argument to copy_thread() is only ever used when forking a new
kernel thread. Hence, rename it to 'kthread_arg' for clarity (and consistency
with do_fork() and other arch-specific implementations of copy_thread()).

Signed-off-by: Alex Dowad <alexinbeijing@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Alex Smith <alex@alex-smith.me.uk>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Eunbong Song <eunb.song@samsung.com>
Cc: linux-mips@linux-mips.org (open list:MIPS)
Patchwork: https://patchwork.linux-mips.org/patch/9546/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-24 15:15:34 +01:00
Steven J. Hill c5b367835c MIPS: Add support for XPA.
Add support for extended physical addressing (XPA) so that
32-bit platforms can access equal to or greater than 40 bits
of physical addresses.

NOTE:
      1) XPA and EVA are not the same and cannot be used
         simultaneously.
      2) If you configure your kernel for XPA, the PTEs
         and all address sizes become 64-bit.
      3) Your platform MUST have working HIGHMEM support.

Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9355/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-19 17:39:49 +01:00
Rusty Russell 8dd928915a mips: fix up obsolete cpu function usage.
Thanks to spatch, plus manual removal of "&*".  Then a sweep for
for_each_cpu_mask => for_each_cpu.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: linux-mips@linux-mips.org
2015-03-05 15:25:06 +10:30
Linus Torvalds a135c717d5 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 MIPS:

   - a number of fixes that didn't make the 3.19 release.

   - a number of cleanups.

   - preliminary support for Cavium's Octeon 3 SOCs which feature up to
     48 MIPS64 R3 cores with FPU and hardware virtualization.

   - support for MIPS R6 processors.

     Revision 6 of the MIPS architecture is a major revision of the MIPS
     architecture which does away with many of original sins of the
     architecture such as branch delay slots.  This and other changes in
     R6 require major changes throughout the entire MIPS core
     architecture code and make up for the lion share of this pull
     request.

   - finally some preparatory work for eXtendend Physical Address
     support, which allows support of up to 40 bit of physical address
     space on 32 bit processors"

     [ Ahh, MIPS can't leave the PAE brain damage alone.  It's like
       every CPU architect has to make that mistake, but pee in the snow
       by changing the TLA.  But whether it's called PAE, LPAE or XPA,
       it's horrid crud   - Linus ]

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (114 commits)
  MIPS: sead3: Corrected get_c0_perfcount_int
  MIPS: mm: Remove dead macro definitions
  MIPS: OCTEON: irq: add CIB and other fixes
  MIPS: OCTEON: Don't do acknowledge operations for level triggered irqs.
  MIPS: OCTEON: More OCTEONIII support
  MIPS: OCTEON: Remove setting of processor specific CVMCTL icache bits.
  MIPS: OCTEON: Core-15169 Workaround and general CVMSEG cleanup.
  MIPS: OCTEON: Update octeon-model.h code for new SoCs.
  MIPS: OCTEON: Implement DCache errata workaround for all CN6XXX
  MIPS: OCTEON: Add little-endian support to asm/octeon/octeon.h
  MIPS: OCTEON: Implement the core-16057 workaround
  MIPS: OCTEON: Delete unused COP2 saving code
  MIPS: OCTEON: Use correct instruction to read 64-bit COP0 register
  MIPS: OCTEON: Save and restore CP2 SHA3 state
  MIPS: OCTEON: Fix FP context save.
  MIPS: OCTEON: Save/Restore wider multiply registers in OCTEON III CPUs
  MIPS: boot: Provide more uImage options
  MIPS: Remove unneeded #ifdef __KERNEL__ from asm/processor.h
  MIPS: ip22-gio: Remove legacy suspend/resume support
  mips: pci: Add ifdef around pci_proc_domain
  ...
2015-02-21 19:41:38 -08:00
Aleksey Makarov 69f7cd4724 MIPS: OCTEON: Delete unused COP2 saving code
Commit 2c952e06e4 ("MIPS: Move cop2 save/restore to switch_to()")
removes assembler code to store COP2 registers.  Commit
a36d8225bc ("MIPS: OCTEON: Enable use of FPU") mistakenly
restores it

Fixes: a36d8225bc ("MIPS: OCTEON: Enable use of FPU")
Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: David Daney <david.daney@cavium.com>
Patchwork: https://patchwork.linux-mips.org/patch/8937/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-20 15:30:23 +01:00
Chandrakala Chavva 2d98cae6e3 MIPS: OCTEON: Use correct instruction to read 64-bit COP0 register
Use dmfc0/dmtc0 instructions for reading CvmMemCtl COP0 register,
its a 64-bit wide.

Signed-off-by: Chandrakala Chavva <cchavva@caviumnetworks.com>
Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: David Daney <david.daney@cavium.com>
Patchwork: https://patchwork.linux-mips.org/patch/8936/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-20 15:29:36 +01:00
David Daney 6b3a287e63 MIPS: OCTEON: Save and restore CP2 SHA3 state
Allocate new save space, and then save/restore the registers if
OCTEON III.

Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8935/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-20 15:29:08 +01:00
David Daney d6e41525e3 MIPS: OCTEON: Fix FP context save.
It wasn't being saved on task switch.

Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8934/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-20 15:28:51 +01:00
David Daney ac655fb762 MIPS: OCTEON: Save/Restore wider multiply registers in OCTEON III CPUs
The wide multiplier is twice as wide, so we need to save twice as much
state.  Detect the multiplier type (CPU type) at start up and install
model specific handlers.

[aleksey.makarov@auriga.com:
	conflict resolution,
	support for old compilers]

Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Leonid Rosenboim <lrosenboim@caviumnetworks.com>
Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8933/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-20 15:28:29 +01:00
Steven J. Hill a5770df095 MIPS: Add set/clear CP0 macros for PageGrain register
Build set and clear macros for the PageGrain register.

Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9289/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-20 12:55:18 +01:00
Ralf Baechle 661af35e5f Merge branch 'mipsr6-for-3.20' of git://git.linux-mips.org/pub/scm/mchandras/linux into mips-for-linux-next 2015-02-19 16:00:34 +01:00
James Hogan ca5d25642e MIPS: Export MSA functions used by lose_fpu(1) for KVM
Export the _save_msa asm function used by the lose_fpu(1) macro to GPL
modules so that KVM can make use of it when it is built as a module.

This fixes the following build error when CONFIG_KVM=m and
CONFIG_CPU_HAS_MSA=y due to commit f798217dfd ("KVM: MIPS: Don't leak
FPU/DSP to guest"):

ERROR: "_save_msa" [arch/mips/kvm/kvm.ko] undefined!

Fixes: f798217dfd (KVM: MIPS: Don't leak FPU/DSP to guest)
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 3.15+
Patchwork: https://patchwork.linux-mips.org/patch/9261/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-19 15:59:44 +01:00
James Hogan 3ce465e04b MIPS: Export FP functions used by lose_fpu(1) for KVM
Export the _save_fp asm function used by the lose_fpu(1) macro to GPL
modules so that KVM can make use of it when it is built as a module.

This fixes the following build error when CONFIG_KVM=m due to commit
f798217dfd ("KVM: MIPS: Don't leak FPU/DSP to guest"):

ERROR: "_save_fp" [arch/mips/kvm/kvm.ko] undefined!

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Fixes: f798217dfd (KVM: MIPS: Don't leak FPU/DSP to guest)
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 3.10+
Patchwork: https://patchwork.linux-mips.org/patch/9260/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-19 15:58:51 +01:00
Markos Chandras 46490b5725 MIPS: kernel: elf: Improve the overall ABI and FPU mode checks
The previous implementation did not cover all possible FPU combinations
and it silently allowed ABI incompatible objects to be loaded with the
wrong ABI. For example, the previous logic would set the FP_64 ABI as
the matching ABI for an FP_XX object combined with an FP_64A object.
This was wrong, and the matching ABI should have been FP_64A.
The previous logic is now replaced with a new one which determines
the appropriate FPU mode to be used rather than the FP ABI. This has
the advantage that the entire logic is much simpler since it is the FPU
mode we are interested in rather than the FP ABI resulting to code
simplifications. This also removes the now obsolete FP32XX_HYBRID_FPRS
option.

Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:39 +00:00
Markos Chandras 13e45f0957 MIPS: kernel: process: Do not allow FR=0 on MIPS R6
A prctl() call to set FR=0 for MIPS R6 should not be allowed
since FR=1 is the only option for R6 cores.

Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Matthew Fortune <matthew.fortune@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:38 +00:00
Markos Chandras 7c151d3d5d MIPS: Make use of the ERETNC instruction on MIPS R6
The ERETNC instruction, introduced in MIPS R5, is similar to the ERET
one, except it does not clear the LLB bit in the LLADDR register.
This feature is necessary to safely emulate R2 LL/SC instructions.
However, on context switches, we need to clear the LLAddr/LLB bit
in order to make sure that an SC instruction from the new thread
will never succeed if it happens to interrupt an LL operation on the
same address from the previous thread.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:37 +00:00
Leonid Yegoshin b0a668fb20 MIPS: kernel: mips-r2-to-r6-emul: Add R2 emulator for MIPS R6
MIPS R6 removed quite a few R2 instructions. However, there
is plenty of <R6 userland code so we add an in-kernel emulator
so we can still be able to execute all R2 userland out there.

The emulator comes with a handy debugfs under /mips/ directory
(r2-emul-stats) to provide some basic statistics of the
instructions that are being emulated.

Below are some statistics from booting a minimal buildroot image:

Instruction     Total   BDslot
------------------------------
movs            236969  0
hilo            56686   0
muls            55279   0
divs            10941   0
dsps            0       0
bops            1       0
traps           0       0
fpus            0       0
loads           214981  17
stores          103364  0
llsc            56898   0
dsemul          150418  0
jr              370158
bltzl           43
bgezl           1594
bltzll          0
bgezll          0
bltzal          39
bgezal          39
beql            14503
bnel            138741
blezl           0
bgtzl           3988

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:37 +00:00
Markos Chandras 5aed9da128 MIPS: Add LLB bit and related feature for the Config 5 CP0 register
The LLBIT (bit 4) in the Config5 CP0 register indicates the software
availability of the Load-Linked bit. This bit is only set by hardware
and it has the following meaning:

0: LLB functionality is not supported
1: LLB functionality is supported. The following feature are also
supported:

- ERETNC instruction. Similar to ERET but it does not clear the LLB
bit in the LLAddr register.
- CP0 LLAddr/LLB bit must be set
- LLbit is software accessible through the LLAddr[0]

This will be used later on to emulate R2 LL/SC instructions.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:36 +00:00
Markos Chandras 28d6f93d20 MIPS: Emulate the new MIPS R6 BNEZC and JIALC instructions
MIPS R6 uses the <R6 sdc2 opcode for the new BNEZC and JIALC instructions

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:35 +00:00
Markos Chandras 69b9a2fd05 MIPS: Emulate the new MIPS R6 BEQZC and JIC instructions
MIPS R6 uses the <R6 ldc2 opcode for the new BEQZC and JIC instructions

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:35 +00:00
Markos Chandras 84fef63012 MIPS: Emulate the new MIPS R6 BALC instruction
MIPS R6 uses the <R6 swc2 opcode for the new BALC instructions.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:35 +00:00
Markos Chandras 10d962d534 MIPS: Emulate the new MIPS R6 BNVC, BNEC and BNEZLAC instructions
MIPS R6 uses the <R6 DADDI opcode for the new BNVC, BNEC and
BNEZLAC instructions.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:34 +00:00
Markos Chandras c893ce38b2 MIPS: Emulate the new MIPS R6 BOVC, BEQC and BEQZALC instructions
MIPS R6 uses the <R6 ADDI opcode for the new BOVC, BEQC and
BEQZALC instructions.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:34 +00:00
Markos Chandras 8467ca0122 MIPS: Emulate the new MIPS R6 branch compact (BC) instruction
MIPS R6 uses the <R6 LWC2 opcode for the new BC instruction.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:34 +00:00
Markos Chandras f1b44067c1 MIPS: Emulate the new MIPS R6 B{L,G}T{Z,}{AL,}C instructions
MIPS R6 added the following four instructions which share the
BGTZ and BGTZL opcode:

BLTZALC: Compact branch-and-link if GPR rt is < to zero
BGTZALC: Compact branch-and-link if GPR rt is > to zero
BLTZL  : Compact branch if GPR rt is < to zero
BGTZL  : Compact branch if GPR rt is > to zero
BLTC   : Compact branch if GPR rs is less than GPR rt
BLTUC  : Similar to BLTC but unsigned

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:33 +00:00
Markos Chandras a8ff66f52d MIPS: Emulate the new MIPS R6 B{L,G}Ε{Z,}{AL,}C instructions
MIPS R6 added the following four instructions which share the
BLEZ and BLEZL opcodes:

BLEZALC: Compact branch-and-link if GPR rt is <= to zero
BGEZALC: Compact branch-and-link if GPR rt is >= to zero
BLEZC  : Compact branch if GPR rt is <= to zero
BGEZC  : Compact branch if GPR rt is >= to zero
BGEC   : Compact branch if GPR rs is less than or equal to GPR rt
BGEUC  : Similar to BGEC but unsigned.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:33 +00:00
Markos Chandras c8a34581ec MIPS: Emulate the BC1{EQ,NE}Z FPU instructions
MIPS R6 introduced the following two branch instructions for COP1:

BC1EQZ: Branch if Cop1 (FPR) Register Bit 0 is Equal to Zero
BC1NEZ: Branch if Cop1 (FPR) Register Bit 0 is Not Equal to Zero

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:32 +00:00
Markos Chandras 319824eabc MIPS: kernel: branch: Do not emulate the branch likelies on MIPS R6
MIPS R6 removed the BLTZL, BGEZL, BLTZAL, BGEZAL, BEQL, BNEL, BLEZL,
BGTZL branch likely instructions so we must not try to emulate them on
MIPS R6 if the R2-to-R6 emulator is not present.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:32 +00:00
Markos Chandras 5f9f41c474 MIPS: kernel: Prepare the JR instruction for emulation on MIPS R6
The MIPS R6 JR instruction is an alias to the JALR one, so it may
need emulation for non-R6 userlands.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:31 +00:00
Markos Chandras fee313d4b8 MIPS: kernel: syscall: Set the appropriate ISA level for MIPS R6
MIPS R6 changed the opcodes for LL/SC instructions so we need to set
the appropriate ISA level.

Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:29 +00:00
Leonid Yegoshin 0593a44c64 MIPS: kernel: unaligned: Add support for the MIPS R6
The load/store unaligned instructions have been removed in MIPS R6
so we need to re-implement the related macros using the regular
load/store instructions. Moreover, the load/store from coprocessor 2
instructions have been reallocated in Release 6 so we will handle them
in the emulator instead.

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:28 +00:00
Markos Chandras acac4108df MIPS: kernel: cps-vec: Replace "addi" with "addiu"
The "addi" instruction will trap on overflows which is not something
we need in this code, so we replace that with "addiu".

Link: http://www.linux-mips.org/archives/linux-mips/2015-01/msg00430.html
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: <stable@vger.kernel.org> # v3.15+
Cc: Paul Burton <paul.burton@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:28 +00:00
Markos Chandras 938c12824b MIPS: kernel: genex: Set correct ISA level
The jr instruction opcode has changed in R6 so make sure
the correct ISA level is set prior using that instruction.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:28 +00:00
Leonid Yegoshin 8d5b9b771e MIPS: kernel: r4k_fpu: Add support for MIPS R6
Add the MIPS R6 related preprocessor definitions for FPU signal
related functions. MIPS R6 only has FR=1 so avoid checking that
bit on the C0/Status register.

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:27 +00:00
Leonid Yegoshin 207083b1da MIPS: kernel: r4k_switch: Add support for MIPS R6
Add the MIPS R6 related preprocessor definitions for save/restore
FPU related functions. We also set the appropriate ISA level
so the final return instruction "jr ra" will produce the correct
opcode on R6.

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:27 +00:00
Leonid Yegoshin 9c7d576868 MIPS: kernel: traps: Add MIPS R6 related definitions
Add MIPS R6 support to cache and ftlb exceptions, as well as
to the hwrena and ebase register configuration.

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:27 +00:00
Markos Chandras 515a6393db MIPS: kernel: proc: Add MIPS R6 support to /proc/cpuinfo
Print 'mips64r6' and/or 'mips32r6' if the kernel is running on
a MIPS R6 core.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:26 +00:00
Markos Chandras 6ebb496ffc MIPS: kernel: entry.S: Add MIPS R6 related definitions
The instruction hazard barrier in the form of:

jr.hb	ra
nop

is valid on MIPS R6 as well.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:26 +00:00
Leonid Yegoshin 8b8aa636f0 MIPS: kernel: cpu-probe.c: Add support for MIPS R6
Add MIPS R6 support when decoding the config0 c0 register.
Also add MIPS R6 support when examining the ebase c0 register
to get the core number and when getting the shadow set number
from the srsctl c0 register.

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:25 +00:00
Leonid Yegoshin 54dac95083 MIPS: kernel: cevt-r4k: Add MIPS R6 to the c0_compare_interrupt handler
Just like MIPS R2, in MIPS R6 it is possible to determine if a
timer interrupt has happened or not.

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:25 +00:00
Leonid Yegoshin 180b1e3bfe MIPS: kernel: cpu-bugs64: Do not check R6 cores for existing 64-bit bugs
The current HW bugs checked in cpu-bugs64, do not apply to R6 cores
and they cause compilation problems due to removed <R6 instructions,
so do not check for them for the time being.

Reviewed-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:24 +00:00
Markos Chandras a7e07b1ae5 MIPS: asm: spram: Add new symbol for MIPS scratch pad storage
MIPS R6, just like MIPS R2, have scratch pad storage, so add a new
symbol which is selected by MIPS R2 and R6.

Link: http://www.linux-mips.org/archives/linux-mips/2015-01/msg00389.html
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:20 +00:00
Markos Chandras 4e0748f5be MIPS: Use generic checksum functions for MIPS R6
The following instructions have been removed from MIPS R6

ulw, ulh, swl, lwr, lwl, swr.

However, all of them are used in the MIPS specific checksum implementation.
As a result of which, we will use the generic checksum on MIPS R6

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17 15:37:19 +00:00
Leonid Yegoshin b2498af56a MIPS: Add MIPS generic QEMU probe support
Add a case in cpu_probe_mips for the MIPS generic QEMU processor ID.

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-16 10:01:24 +00:00
Leonid Yegoshin 4695089f03 MIPS: Add cases for CPU_QEMU_GENERIC
Add a CPU_QEMU_GENERIC case to various switch statements.

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-16 10:01:24 +00:00
Markos Chandras ed4cbc81ad MIPS: HTW: Prevent accidental HTW start due to nested htw_{start, stop}
activate_mm() and switch_mm() call get_new_mmu_context() which in turn
can enable the HTW before the entryhi is changed with the new ASID.
Since the latter will enable the HTW in local_flush_tlb_all(),
then there is a small timing window where the HTW is running with the
new ASID but with an old pgd since the TLBMISS_HANDLER_SETUP_PGD
hasn't assigned a new one yet. In order to prevent that, we introduce a
simple htw counter to avoid starting HTW accidentally due to nested
htw_{start,stop}() sequences. Moreover, since various IPI calls can
enforce TLB flushing operations on a different core, such an operation
may interrupt another htw_{stop,start} in progress leading inconsistent
updates of the htw_seq variable. In order to avoid that, we disable the
interrupts whenever we update that variable.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: <stable@vger.kernel.org> # 3.17+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9118/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-16 10:55:26 +01:00
Andrey Ryabinin cb9e3c292d mm: vmalloc: pass additional vm_flags to __vmalloc_node_range()
For instrumenting global variables KASan will shadow memory backing memory
for modules.  So on module loading we will need to allocate memory for
shadow and map it at address in shadow that corresponds to the address
allocated in module_alloc().

__vmalloc_node_range() could be used for this purpose, except it puts a
guard hole after allocated area.  Guard hole in shadow memory should be a
problem because at some future point we might need to have a shadow memory
at address occupied by guard hole.  So we could fail to allocate shadow
for module_alloc().

Now we have VM_NO_GUARD flag disabling guard page, so we need to pass into
__vmalloc_node_range().  Add new parameter 'vm_flags' to
__vmalloc_node_range() function.

Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13 21:21:42 -08:00
Andy Lutomirski f56141e3e2 all arches, signal: move restart_block to struct task_struct
If an attacker can cause a controlled kernel stack overflow, overwriting
the restart block is a very juicy exploit target.  This is because the
restart_block is held in the same memory allocation as the kernel stack.

Moving the restart block to struct task_struct prevents this exploit by
making the restart_block harder to locate.

Note that there are other fields in thread_info that are also easy
targets, at least on some architectures.

It's also a decent simplification, since the restart code is more or less
identical on all architectures.

[james.hogan@imgtec.com: metag: align thread_info::supervisor_stack]
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: David Miller <davem@davemloft.net>
Acked-by: Richard Weinberger <richard@nod.at>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12 18:54:12 -08:00
Paul Burton 9791554b45 MIPS,prctl: add PR_[GS]ET_FP_MODE prctl options for MIPS
Userland code may be built using an ABI which permits linking to objects
that have more restrictive floating point requirements. For example,
userland code may be built to target the O32 FPXX ABI. Such code may be
linked with other FPXX code, or code built for either one of the more
restrictive FP32 or FP64. When linking with more restrictive code, the
overall requirement of the process becomes that of the more restrictive
code. The kernel has no way to know in advance which mode the process
will need to be executed in, and indeed it may need to change during
execution. The dynamic loader is the only code which will know the
overall required mode, and so it needs to have a means to instruct the
kernel to switch the FP mode of the process.

This patch introduces 2 new options to the prctl syscall which provide
such a capability. The FP mode of the process is represented as a
simple bitmask combining a number of mode bits mirroring those present
in the hardware. Userland can either retrieve the current FP mode of
the process:

  mode = prctl(PR_GET_FP_MODE);

or modify the current FP mode of the process:

  err = prctl(PR_SET_FP_MODE, new_mode);

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Matthew Fortune <matthew.fortune@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8899/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-12 12:30:29 +01:00
James Hogan ae58d882bf MIPS: cevt-r4k: Drop GIC special case
The cevt-r4k driver used to call into the GIC driver to find whether the
timer was pending, but only with External Interrupt Controller (EIC)
mode, where the Cause.IP bits can't be used as they encode the interrupt
priority level (Cause.RIPL) instead.

However commit e9de688dac ("irqchip: mips-gic: Support local
interrupts") changed the condition from cpu_has_veic to gic_present.
This fails on cores such as P5600 which have a GIC but the local
interrupts aren't routable by the GIC, causing c0_compare_int_usable()
to consider the interrupt unusable so r4k_clockevent_init() fails.

The previous behaviour, added in commit 98b67c37db ("MIPS: Add EIC
support for GIC."), wasn't really correct either as far as I can tell,
since P5600 apparently supports EIC mode too, and in any case the use of
Cause.TI with r2 should have been sufficient anyway since commit
010c108d7a ("MIPS: PowerTV: Fix support for timer interrupts with > 64
external IRQs").

Therefore drop the call into the gic driver altogether, and add a
comment in c0_compare_int_pending() to clarify that Cause.TI does get
checked since MIPS r2.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Fixes: e9de688dac ("irqchip: mips-gic: Support local interrupts")
Reviewed-by: Andrew Bresticker <abrestic@chromium.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Steven J. Hill <steven.hill@imgtec.com>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9077/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-05 14:56:53 +01:00
Lars Persson c2d9f17757 MIPS: Fix syscall_get_nr for the syscall exit tracing.
Register 2 is alredy overwritten by the return value when
syscall_trace_leave() is called.

Signed-off-by: Lars Persson <larper@axis.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9187/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-04 16:40:09 +01:00
James Hogan 39148e94e3 MIPS: fork: Fix MSA/FPU/DSP context duplication race
There is a race in the MIPS fork code which allows the child to get a
stale copy of parent MSA/FPU/DSP state that is active in hardware
registers when the fork() is called. This is because copy_thread() saves
the live register state into the child context only if the hardware is
currently in use, apparently on the assumption that the hardware state
cannot have been saved and disabled since the initial duplication of the
task_struct. However preemption is certainly possible during this
window.

An example sequence of events is as follows:

1) The parent userland process puts important data into saved floating
   point registers ($f20-$f31), which are then dirty compared to the
   process' stored context.

2) The parent process calls fork() which does a clone system call.

3) In the kernel, do_fork() -> copy_process() -> dup_task_struct() ->
   arch_dup_task_struct() (which uses the weakly defined default
   implementation). This duplicates the parent process' task context,
   which includes a stale version of its FP context from when it was
   last saved, probably some time before (1).

4) At some point before copy_process() calls copy_thread(), such as when
   duplicating the memory map, the process is desceduled. Perhaps it is
   preempted asynchronously, or perhaps it sleeps while blocked on a
   mutex. The dirty FP state in the FP registers is saved to the parent
   process' context and the FPU is disabled.

5) When the process is rescheduled again it continues copying state
   until it gets to copy_thread(), which checks whether the FPU is in
   use, so that it can copy that dirty state to the child process' task
   context. Because of the deschedule however the FPU is not in use, so
   the child process' context is left with stale FP context from the
   last time the parent saved it (some time before (1)).

6) When the new child process is scheduled it reads the important data
   from the saved floating point register, and ends up doing a NULL
   pointer dereference as a result of the stale data.

This use of saved floating point registers across function calls can be
triggered fairly easily by explicitly using inline asm with a current
(MIPS R2) compiler, but is far more likely to happen unintentionally
with a MIPS R6 compiler where the FP registers are more likely to get
used as scratch registers for storing non-fp data.

It is easily fixed, in the same way that other architectures do it, by
overriding the implementation of arch_dup_task_struct() to sync the
dirty hardware state to the parent process' task context *prior* to
duplicating it, rather than copying straight to the child process' task
context in copy_thread(). Note, the FPU hardware is not disabled so the
parent process may continue executing with the live register context,
but now the child process is guaranteed to have an identical copy of it
at that point.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Reported-by: Matthew Fortune <matthew.fortune@imgtec.com>
Tested-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9075/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-01-31 00:44:19 +01:00
James Hogan d76e9b9fc5 MIPS: traps: Fix inline asm ctc1 missing .set hardfloat
Commit 842dfc11ea ("MIPS: Fix build with binutils 2.24.51+") in v3.18
enabled -msoft-float and sprinkled ".set hardfloat" where necessary to
use FP instructions. However it missed enable_restore_fp_context() which
since v3.17 does a ctc1 with inline assembly, causing the following
assembler errors on Mentor's 2014.05 toolchain:

{standard input}: Assembler messages:
{standard input}:2913: Error: opcode not supported on this processor: mips32r2 (mips32r2) `ctc1 $2,$31'
scripts/Makefile.build:257: recipe for target 'arch/mips/kernel/traps.o' failed

Fix that to use the new write_32bit_cp1_register() macro so that ".set
hardfloat" is automatically added when -msoft-float is in use.

Fixes 842dfc11ea ("MIPS: Fix build with binutils 2.24.51+")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 3.18+, depends on "MIPS: mipsregs.h: Add write_32bit_cp1_register()"
Patchwork: https://patchwork.linux-mips.org/patch/9173/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-01-30 23:05:04 +01:00
Hemmo Nieminen c7754e7510 MIPS: Fix kernel lockup or crash after CPU offline/online
As printk() invocation can cause e.g. a TLB miss, printk() cannot be
called before the exception handlers have been properly initialized.
This can happen e.g. when netconsole has been loaded as a kernel module
and the TLB table has been cleared when a CPU was offline.

Call cpu_report() in start_secondary() only after the exception handlers
have been initialized to fix this.

Without the patch the kernel will randomly either lockup or crash
after a CPU is onlined and the console driver is a module.

Signed-off-by: Hemmo Nieminen <hemmo.nieminen@iki.fi>
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: stable@vger.kernel.org
Cc: 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/8953/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-01-29 23:54:07 +01:00
Felix Fietkau a3e6c1eff5 MIPS: IRQ: Fix disable_irq on CPU IRQs
If the irq_chip does not define .irq_disable, any call to disable_irq
will defer disabling the IRQ until it fires while marked as disabled.
This assumes that the handler function checks for this condition, which
handle_percpu_irq does not. In this case, calling disable_irq leads to
an IRQ storm, if the interrupt fires while disabled.

This optimization is only useful when disabling the IRQ is slow, which
is not true for the MIPS CPU IRQ.

Disable this optimization by implementing .irq_disable and .irq_enable

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Cc: stable@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8949/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-01-16 14:03:17 +01:00
James Hogan c3f134fb39 MIPS: smp-mt,smp-cmp: Enable all HW IRQs on secondary CPUs
Commit 18743d2781 ("irqchip: mips-gic: Stop using per-platform mapping
tables") in v3.19-rc1 changed the routing of IPIs through the GIC to go
to the HW0 IRQ pin along with the rest of the GIC interrupts, rather
than to HW1 and HW2 pins.

This breaks SMP boot using the CMP or MT SMP implementations because HW0
doesn't get unmasked when secondary CPUs are initialised so the IPIs
will never interrupt secondary CPUs (nor any other interrupts routed
through the GIC).

Commit ff1e29ade4 ("MIPS: smp-cps: Enable all hardware interrupts on
secondary CPUs") fixed this in advance for the CPS SMP implementation by
unmasking all hardware interrupt lines for secondary CPUs, so lets do
the same for the CMP and MT implementations.

Fixes: 18743d2781 ("irqchip: mips-gic: Stop using per-platform mapping tables")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9025/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-01-16 13:02:40 +01:00
Ed Swierk e967ef022e MIPS: Fix restart of indirect syscalls
When 32-bit MIPS userspace invokes a syscall indirectly via syscall(number,
arg1, ..., arg7), the kernel looks up the actual syscall based on the given
number, shifts the other arguments to the left, and jumps to the syscall.

If the syscall is interrupted by a signal and indicates it needs to be
restarted by the kernel (by returning ERESTARTNOINTR for example), the
syscall must be called directly, since the number is no longer the first
argument, and the other arguments are now staged for a direct call.

Before shifting the arguments, store the syscall number in pt_regs->regs[2].
This gets copied temporarily into pt_regs->regs[0] after the syscall returns.
If the syscall needs to be restarted, handle_signal()/do_signal() copies the
number back to pt_regs->reg[2], which ends up in $v0 once control returns to
userspace.

Signed-off-by: Ed Swierk <eswierk@skyportsystems.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8929/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-01-16 00:35:45 +01:00
James Cowgill fd75a33e00 MIPS: ELF: fix loading o32 binaries on 64-bit kernels
Commit 90cee759f0 ("MIPS: ELF: Set FP mode according to .MIPS.abiflags")
introduced checking of the .MIPS.abiflags ELF section but did so through
the native sized "elfhdr" and "elf_phdr" structures regardless whether the
ELF was actually 32-bit or 64-bit. This produces wrong results when trying
to use a 64-bit kernel to load o32 ELF files.

Change the uses of the generic elf structures to their 32-bit versions.
Since the code bails out on any 64-bit cases, this is OK until they are
implemented.

Fixes: 90cee759f0 ("MIPS: ELF: Set FP mode according to .MIPS.abiflags")
Signed-off-by: James Cowgill <James.Cowgill@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: Maciej W. Rozycki <macro@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/8932/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-01-15 15:59:28 +01:00
Ralf Baechle 389cdc5d35 MIPS: Wire up execveat(2).
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-01-13 15:53:09 +01:00
Jaedon Shin ad8f723afb MIPS: Use phys_addr_t instead of phys_t
Ralf Baechle says:
 "This should have been part of the merge commit c0222ac086 (Merge
  branch 'upstream' of git://git.linux-mips.org/pub/scm/-
  ralf/upstream-linus) but I forgot to mention the need for this in my
  pull request"

Signed-off-by: Jaedon Shin <jaedon.shin@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-12 15:36:13 -08:00
Linus Torvalds c0222ac086 Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull MIPS updates from Ralf Baechle:
 "This is an unusually large pull request for MIPS - in parts because
  lots of patches missed the 3.18 deadline but primarily because some
  folks opened the flood gates.

   - Retire the MIPS-specific phys_t with the generic phys_addr_t.
   - Improvments for the backtrace code used by oprofile.
   - Better backtraces on SMP systems.
   - Cleanups for the Octeon platform code.
   - Cleanups and fixes for the Loongson platform code.
   - Cleanups and fixes to the firmware library.
   - Switch ATH79 platform to use the firmware library.
   - Grand overhault to the SEAD3 and Malta interrupt code.
   - Move the GIC interrupt code to drivers/irqchip
   - Lots of GIC cleanups and updates to the GIC code to use modern IRQ
     infrastructures and features of the kernel.
   - OF documentation updates for the GIC bindings
   - Move GIC clocksource driver to drivers/clocksource
   - Merge GIC clocksource driver with clockevent driver.
   - Further updates to bring the GIC clocksource driver up to date.
   - R3000 TLB code cleanups
   - Improvments to the Loongson 3 platform code.
   - Convert pr_warning to pr_warn.
   - Merge a bunch of small lantiq and ralink fixes that have been
     staged/lingering inside the openwrt tree for a while.
   - Update archhelp for IP22/IP32
   - Fix a number of issues for Loongson 1B.
   - New clocksource and clockevent driver for Loongson 1B.
   - Further work on clk handling for Loongson 1B.
   - Platform work for Broadcom BMIPS.
   - Error handling cleanups for TurboChannel.
   - Fixes and optimization to the microMIPS support.
   - Option to disable the FTLB.
   - Dump more relevant information on machine check exception
   - Change binfmt to allow arch to examine PT_*PROC headers
   - Support for new style FPU register model in O32
   - VDSO randomization.
   - BCM47xx cleanups
   - BCM47xx reimplement the way the kernel accesses NVRAM information.
   - Random cleanups
   - Add support for ATH25 platforms
   - Remove pointless locking code in some PCI platforms.
   - Some improvments to EVA support
   - Minor Alchemy cleanup"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (185 commits)
  MIPS: Add MFHC0 and MTHC0 instructions to uasm.
  MIPS: Cosmetic cleanups of page table headers.
  MIPS: Add CP0 macros for extended EntryLo registers
  MIPS: Remove now unused definition of phys_t.
  MIPS: Replace use of phys_t with phys_addr_t.
  MIPS: Replace MIPS-specific 64BIT_PHYS_ADDR with generic PHYS_ADDR_T_64BIT
  PCMCIA: Alchemy Don't select 64BIT_PHYS_ADDR in Kconfig.
  MIPS: lib: memset: Clean up some MIPS{EL,EB} ifdefery
  MIPS: iomap: Use __mem_{read,write}{b,w,l} for MMIO
  MIPS: <asm/types.h> fix indentation.
  MAINTAINERS: Add entry for BMIPS multiplatform kernel
  MIPS: Enable VDSO randomization
  MIPS: Remove a temporary hack for debugging cache flushes in SMTC configuration
  MIPS: Remove declaration of obsolete arch_init_clk_ops()
  MIPS: atomic.h: Reformat to fit in 79 columns
  MIPS: Apply `.insn' to fixup labels throughout
  MIPS: Fix microMIPS LL/SC immediate offsets
  MIPS: Kconfig: Only allow 32-bit microMIPS builds
  MIPS: signal.c: Fix an invalid cast in ISA mode bit handling
  MIPS: mm: Only build one microassembler that is suitable
  ...
2014-12-11 17:56:37 -08:00
Ralf Baechle 15d45cce3a MIPS: Replace use of phys_t with phys_addr_t.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 22:47:31 +01:00
Prem Karat ccd3988086 MIPS: Enable VDSO randomization
Based on commit 1091458d09 (mmap randomization)

For 32-bit address spaces randomize within a
16MB space, for 64-bit within a 256MB space.

Test Results:
------------
Without Patch (VDSO is not randomized)
---------------------------------------
root@Maleo:~# ./aslr vdso
FAIL: ASLR not functional (vdso always at 0x7fff7000)

root@Maleo:~# ./aslr rekey vdso
pre_val==cur_val
value=0x7fff7000

With patch:(VDSO is randmoized and doesn't interfere with stack)
----------------------------------------------------------------
root@cavium-octeon2:~# ./aslr rekey vdso
pre_val!=cur_val
previous_value=0x7f830ea2
current_value=0x776e2000
root@cavium-octeon2:~# ./aslr rekey vdso
pre_val!=cur_val
previous_value=0x7fb0cea2
current_value=0x77209000
root@cavium-octeon2:~# ./aslr rekey vdso
pre_val!=cur_val
previous_value=0x7f985ea2
current_value=0x7770c000
root@cavium-octeon2:~# ./aslr rekey vdso
pre_val!=cur_val
previous_value=0x7fbc6ea2
current_value=0x7fe25000

Maps file output:
-------------------------
root@cavium-octeon2:~# ./aslr rekey maps
78584000-785a5000 rwxp 00000000 00:00 0                                  [heap]
7f9d0000-7f9f1000 rw-p 00000000 00:00 0                                  [stack]
7ffa5000-7ffa6000 r-xp 00000000 00:00 0                                  [vdso]

root@cavium-octeon2:~# ./aslr rekey maps
77de0000-77e01000 rwxp 00000000 00:00 0                                  [heap]
7f91b000-7f93c000 rw-p 00000000 00:00 0                                  [stack]
7ff99000-7ff9a000 r-xp 00000000 00:00 0                                  [vdso]

root@cavium-octeon2:~# ./aslr rekey maps
77d7f000-77da0000 rwxp 00000000 00:00 0                                  [heap]
7fc2a000-7fc4b000 rw-p 00000000 00:00 0                                  [stack]
7fe09000-7fe0a000 r-xp 00000000 00:00 0                                  [vdso]

root@cavium-octeon2:~# ./aslr rekey maps
7794c000-7794d000 r-xp 00000000 00:00 0                                  [vdso]
77e4b000-77e6c000 rwxp 00000000 00:00 0                                  [heap]
7f6e7000-7f708000 rw-p 00000000 00:00 0                                  [stack]
root@cavium-octeon2:~#

Signed-off-by: Prem Karat <pkarat@mvista.com>
Cc: linux-mips@linux-mips.org
Cc: sergei.shtylyov@cogentembedded.com
Cc: ddaney.cavm@gmail.com
Patchwork: https://patchwork.linux-mips.org/patch/6812
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:38 +01:00
Maciej W. Rozycki 0e525e48f7 MIPS: Apply `.insn' to fixup labels throughout
Fix the issue with the ISA bit being lost in fixups that jump to labels
placed just before a section switch.  Such a switch leads to the ISA bit
being lost, because GAS concludes there is no code that follows and
therefore the label refers to data.  Use the `.insn' pseudo-op to
convince the tool this is not the case.

This lack of label annotation leads to microMIPS compilation errors
like:

mips-linux-gnu-ld: arch/mips/built-in.o: .fixup+0x3b8: Unsupported jump between ISA modes; consider recompiling with interlinking enabled.
mips-linux-gnu-ld: final link failed: Bad value

Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com>
Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8483/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:36 +01:00
Maciej W. Rozycki 2fabc7d25d MIPS: signal.c: Fix an invalid cast in ISA mode bit handling
Fix:

arch/mips/kernel/signal.c: In function 'handle_signal':
arch/mips/kernel/signal.c:533:21: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
  unsigned int tmp = (unsigned int)current->mm->context.vdso;
                     ^
arch/mips/kernel/signal.c:536:9: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
  vdso = (void *)tmp;
         ^
cc1: all warnings being treated as errors

when building a 64-bit kernel.

This is not really a supported configuration, but the cast is wrong
either way, Linux makes the assumption that sizeof(void *) equals
sizeof(unsigned long) and therefore the latter type is expected to be
used where integer operations have to be applied to pointers for some
reason.

Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8480/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:36 +01:00
Markos Chandras 26b40ef1aa MIPS: traps: Dump the PageGrain and Wired registers on MC
They can be useful to determine how the MMU is configured on a MC
exception.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8401/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:31 +01:00
Markos Chandras 31ec86b854 MIPS: traps: Dump the HTW registers on a MC exception
The HTW registers can be useful to debug a MC exception.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8400/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:31 +01:00
Markos Chandras 314727fe5c MIPS: traps: Replace printk with pr_err for MC exceptions
printk should not be used without a KERN_ facility level

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8399/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:30 +01:00
Andrew Bresticker a331ce63c8 clocksource: mips-gic: Combine with GIC clockevent driver
Combine the GIC clocksource driver with the GIC clockevent driver from
arch/mips/kernel/cevt-gic.c and remove the clockevent driver's separate
Kconfig symbol.

Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: John Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8132/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:15 +01:00
Andrew Bresticker fa5635a277 MIPS: Move GIC clocksource driver to drivers/clocksource/
Move the GIC clocksource driver to drivers/clocksource/mips-gic-timer.c.

Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: John Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8133/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:14 +01:00
Kevin Cernekee 84988c0681 MIPS: Create a helper function for DT setup
A couple of platforms register two buses and call of_platform_populate().
Move this into a common function to reduce duplication.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Cc: f.fainelli@gmail.com
Cc: mbizon@freebox.fr
Cc: jogo@openwrt.org
Cc: jfraser@broadcom.com
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8167/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:12 +01:00
Kevin Cernekee 68e6a78373 MIPS: BMIPS: Add PRId for BMIPS5200 (Whirlwind)
This is a dual core (quad thread) BMIPS5000.  It needs a little extra
code to boot the second core (CPU2/CPU3), but for now we can treat it the
same as a single core BMIPS5000.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Cc: f.fainelli@gmail.com
Cc: mbizon@freebox.fr
Cc: jogo@openwrt.org
Cc: jfraser@broadcom.com
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8166/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:12 +01:00
Kevin Cernekee d8010ceba6 MIPS: BMIPS: Let each platform customize the CPU1 IRQ mask
On some chips like bcm3384, "other stuff" gets wired up to CPU1's IE_IRQ1
input, generating spurious IRQs.  In this case we want the platform code
to be able to mask it off.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Cc: f.fainelli@gmail.com
Cc: mbizon@freebox.fr
Cc: jogo@openwrt.org
Cc: jfraser@broadcom.com
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8163/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:11 +01:00
Kevin Cernekee 3677a28362 MIPS: BMIPS: Explicitly configure reset vectors prior to secondary boot
The secondary CPU's reset vector needs to be set to KSEG1 for a cold
boot (release from reset), or KSEG0 for a warm restart.  On a cold boot
KSEG0 may be unavailable (BMIPS4380), and on a warm restart KSEG1 may
be unavailable (XKS01 mode on 4380 or 5000).

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Cc: f.fainelli@gmail.com
Cc: mbizon@freebox.fr
Cc: jogo@openwrt.org
Cc: jfraser@broadcom.com
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8161/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:10 +01:00
Jon Fraser 230b6ff575 MIPS: BMIPS: Mask off timer IRQs when hot-unplugging a CPU
CPU interrupts need to be disabled on a cpu being taken down.
When a cpu is hot-plugged out of the system the following sequence occurs.

On the CPU where the hotplug sequence was initiated:
    cpu_down
        _cpu_down {
            __cpu_notify(CPU_DOWN_PREPARE
            __stop_machine(take_cpu_down
                wait for cpu to run disable code.
            __cpu_die
        }

On the CPU  being disabled:
    take_cpu_down
        __cpu_disable {
            mp_ops->cpu_disable
                bmips_cpu_disable
                    clear_c0_status(IE_IRQ5) (added)
            cpu_notify(CPU_DYING...
        }

Before the cpu_notifier is called with CPU_DYING, all interrupts on the
dying cpu must be disabled.  This guarantees that before tick_notify is
called with the CPU_DYING event and sets the clock device pointer to
NULL, there can not be any more clock interrupts.

When this wasn't done, an unfortunately-timed timer interrupt sometimes
caused hangs immediately prior to system suspend:

    Debug PM is not enabled. To enable partial suspend, rebuild kernel with CONFIG_PM_DEBUG
    Pass 1 out of 1,PM: Syncing filesystems ... mode=none, tp1=done.
    1, flags=5, cycle_tp=, sleep=
    Freezing user space processes ... (elapsed 0.01 seconds) done.
    Freezing remaining freezable tasks ... (elapsed 0.01 seconds) done.
    PM: suspend of devices complete after 54.199 msecs
    PM: late suspend of devices complete after 0.172 msecs
    Disabling non-boot CPUs ...
    SMP: CPU1 is offline
    INFO: rcu_sched detected stalls on CPUs/tasks: { 3} (detected by 0, t=62537 jiffies)
    Call Trace:
    [<804baa78>] dump_stack+0x8/0x34
    [<8008a2d8>] __rcu_pending+0x4b8/0x55c
    [<8008adf4>] rcu_check_callbacks+0x78/0x180
    [<80037830>] update_process_times+0x40/0x6c
    [<80072fe4>] tick_sched_timer+0x74/0xe4
    [<80050180>] __run_hrtimer.clone.30+0x64/0x140
    [<80051150>] hrtimer_interrupt+0x19c/0x4bc
    [<8000cdb8>] c0_compare_interrupt+0x50/0x88
    [<80081b18>] handle_irq_event_percpu+0x5c/0x2f4
    [<80086490>] handle_percpu_irq+0x8c/0xc0
    [<800811b4>] generic_handle_irq+0x34/0x54
    [<800067dc>] do_IRQ+0x18/0x2c
    [<8000375c>] plat_irq_dispatch+0xd0/0x128
    [<80004a04>] ret_from_irq+0x0/0x4
    [<80004c40>] r4k_wait+0x20/0x40
    [<80006b6c>] cpu_idle+0x98/0xf0
    [<805d3988>] start_kernel+0x424/0x440

Signed-off-by: Jon Fraser <jfraser@broadcom.com>
Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Cc: f.fainelli@gmail.com
Cc: mbizon@freebox.fr
Cc: jogo@openwrt.org
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8160/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:10 +01:00
Jon Fraser fa01067259 MIPS: BMIPS: Allow BMIPS3300 to utilize SMP ebase relocation code
BMIPS3300 processors do not have the hardware to support SMP, but with a
small tweak, the SMP ebase relocation code allows BMIPS3300-based
platforms to reuse the S2/S3 power management code from BMIPS4380-based
chips.  Normally this is as simple as adding one line to prom_init():

    board_ebase_setup = &bmips_ebase_setup;

Signed-off-by: Jon Fraser <jfraser@broadcom.com>
Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Cc: f.fainelli@gmail.com
Cc: mbizon@freebox.fr
Cc: jogo@openwrt.org
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8159/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:10 +01:00
Kevin Cernekee fc45578793 MIPS: BMIPS: Introduce helper function to change the reset vector
This will need to be called from a few different places, and the logic
is starting to get a bit hairy (with the need for IPIs, CPU bug
workarounds, and hazards).

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Cc: f.fainelli@gmail.com
Cc: mbizon@freebox.fr
Cc: jogo@openwrt.org
Cc: jfraser@broadcom.com
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8158/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:10 +01:00
Kevin Cernekee bdb2e05c90 MIPS: BMIPS: Align secondary boot sequence with latest firmware releases
On some older BMIPS5200 (dual core / quad thread) platforms, the
PROM code set up CPU2/CPU3 so they would be started through an NMI
instead of through the ACTION register.  But this was incompatible with
some power management features that were later added, so the scheme was
changed so that Linux is fully responsible for booting CPU2/CPU3.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Cc: f.fainelli@gmail.com
Cc: mbizon@freebox.fr
Cc: jogo@openwrt.org
Cc: jfraser@broadcom.com
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8157/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:10 +01:00
Paul Burton f4af6fb2fc MIPS: Kconfig option to better exercise/debug hybrid FPRs
The hybrid FPR scheme exists to allow for compatibility between existing
FP32 code and newly compiled FP64A code. Such code should hopefully be
rare in the real world, and for the moment is difficult to come across.
All code except that built for the FP64 ABI can correctly execute using
the hybrid FPR scheme, so debugging the hybrid FPR implementation can
be eased by forcing all such code to use it. This is undesirable in
general due to the trap & emulate overhead of the hybrid FPR
implementation, but is a very useful option to have for debugging.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7680/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:08 +01:00
Paul Burton 90cee759f0 MIPS: ELF: Set FP mode according to .MIPS.abiflags
This patch reads the .MIPS.abiflags section when it is present, and sets
the FP mode of the task accordingly. Any loaded ELF files which do not
contain a .MIPS.abiflags section will continue to observe the previous
behaviour, that is FR=1 if EF_MIPS_FP64 is set else FR=0.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7681/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:07 +01:00
Paul Burton 4227a2d4ef MIPS: Support for hybrid FPRs
Hybrid FPRs is a scheme where scalar FP registers are 64b wide, but
accesses to odd indexed single registers use bits 63:32 of the
preceeding even indexed 64b register. In this mode all FP code
except that built for the plain FP64 ABI can execute correctly. Most
notably a combination of FP64A & FP32 code can execute correctly,
allowing for existing FP32 binaries to be linked with new FP64A binaries
that can make use of 64 bit FP & MSA.

Hybrid FPRs are implemented by setting both the FR & FRE bits, trapping
& emulating single precision FP instructions (via Reserved Instruction
exceptions) whilst allowing others to execute natively. It therefore has
a penalty in terms of execution speed, and should only be used when no
fully native mode can be. As more binaries are recompiled to use either
the FPXX or FP64(A) ABIs, the need for hybrid FPRs should diminish.
However in the short to mid term it allows for a gradual transition
towards that world, rather than a complete ABI break which is not
feasible for some users & not desirable for many.

A task will be executed using the hybrid FPR scheme when its
TIF_HYBRID_FPREGS flag is set & TIF_32BIT_FPREGS is clear. A further
patch will set the flags as necessary, this patch simply adds the
infrastructure necessary for the hybrid FPR mode to work.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7683/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:07 +01:00
Paul Burton d175ed2bd6 MIPS: Ensure Config5.UFE is clear on boot
As is done for UFR, ensure that userland cannot directly manipulate the
mode by clearing the UFE bit during boot.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7677/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:07 +01:00
Paul Burton adac5d535d MIPS: detect presence of the FRE & UFR bits
Detect the presence of the Config5 FRE & UFE bits, as indicated by the
FREP bit in FPIR. Record this as a CPU option bit, and provide a
cpu_has_fre macro to ease checking of that option bit.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7678/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:06 +01:00
Ralf Baechle 4ff3fccd86 MIPS: Remove __strlen_user().
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:00 +01:00
Andrew Bresticker 4060bbe993 MIPS: Move gic.h to include/linux/irqchip/mips-gic.h
Now that the MIPS GIC irqchip lives in drivers/irqchip/, move
its header over to include/linux/irqchip/.

Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: John Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8129/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:44:59 +01:00
Andrew Bresticker 387904ff84 irqchip: mips-gic: Export function to read counter width
Export the function gic_get_count_width to read the width of
the GIC global counter from GIC_SH_CONFIG.  Update the GIC
clocksource driver to use this new function.

Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: John Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8124/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:44:57 +01:00