On CPUs which support the EBase WG (write gate) flag, the most
significant bits of the exception base can be changed. Firmware running
on a VP(E) using MIPS rproc may change EBase to point into the user
segment where the firmware is located such that it can service
interrupts. When control is transferred back to the kernel the EBase
must be switched back into the kernel segment, such that the kernel's
exception vectors are used.
Similarly when vectored interrupts (vint) or vectored external interrupt
controllers (veic) are enabled an exception vector is allocated from
bootmem, and written to the EBase register. Due to the WG flag being
clear, only bits 29:12 will be written. Asside from the rproc case above
this is normally fine (as it will usually be a low allocation within the
KSeg0 range, however when Enhanced Virtual Addressing (EVA) is enabled
the allocation may be outside of the traditional KSeg0/KSeg1 address
range, resulting in the wrong EBase being written.
Correct both cases (configure_exception_vector() for the boot CPU, and
per_cpu_trap_init() for secondary CPUs) to write EBase with the WG flag
first if supported.
On the Malta EVA configuration, KSeg0 is mapped to physical address 0,
and memory is allocated from the KUSeg segment which is mapped to
physical address 0x80000000, which physically aliases the RAM at 0. This
only worked due to the exception base address aliasing the same
underlying RAM that was written to & cache flushed, and due to
flush_icache_range() going beyond the call of duty and flushing from the
L2 cache too (due to the differing physical addresses).
Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
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/14150/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
When allocating boot memory for the exception vector when vectored
interrupts (vint) or vectored external interrupt controllers (veic) are
enabled, try to ensure that the virtual address resides in KSeg0 (and
WARN should that not be possible).
This will be helpful on MIPS64 cores supporting the CP0_EBase Write Gate
(WG) bit once we start using the WG bit to write the full ebase into
CP0_EBase, as we ideally need to avoid hitting the architecturally
poorly defined exception base for Cache Errors when CP0_EBase is in
XKPhys.
An exception is made for Enhanced Virtual Addressing (EVA) kernels which
allow segments to be rearranged and to become uncached during cache
error handling, making it valid for ebase to be elsewhere.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14149/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
When reading the CP0_EBase register containing the WG (write gate) bit,
the ebase variable should be set to the full value of the register, i.e.
on a 64-bit kernel the full 64-bit width of the register via
read_cp0_ebase_64(), and on a 32-bit kernel the full 32-bit width
including bits 31:30 which may be writeable.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14148/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
These files were only including module.h for exception table
related functions. We've now separated that content out into its
own file "extable.h" so now move over to that and avoid all the
extra header content in module.h that we don't really need to compile
these files.
In the case of traps.c we can't dump the module.h include since it is
also used to provide "print_modules".
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13934/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Pull MIPS updates from Ralf Baechle:
"This is the main pull request for MIPS for 4.8. Also includes is a
minor SSB cleanup as SSB code traditionally is merged through the MIPS
tree:
ATH25:
- MIPS: Add default configuration for ath25
Boot:
- For zboot, copy appended dtb to the end of the kernel
- store the appended dtb address in a variable
BPF:
- Fix off by one error in offset allocation
Cobalt code:
- Fix typos
Core code:
- debugfs_create_file returns NULL on error, so don't use IS_ERR for
testing for errors.
- Fix double locking issue in RM7000 S-cache code. This would only
affect RM7000 ARC systems on reboot.
- Fix page table corruption on THP permission changes.
- Use compat_sys_keyctl for 32 bit userspace on 64 bit kernels.
David says, there are no compatibility issues raised by this fix.
- Move some signal code around.
- Rewrite r4k count/compare clockevent device registration such that
min_delta_ticks/max_delta_ticks files are guaranteed to be
initialized.
- Only register r4k count/compare as clockevent device if we can
assume the clock to be constant.
- Fix MSA asm warnings in control reg accessors
- uasm and tlbex fixes and tweaking.
- Print segment physical address when EU=1.
- Define AT_VECTOR_SIZE_ARCH for ARCH_DLINFO.
- CP: Allow booting by VP other than VP 0
- Cache handling fixes and optimizations for r4k class caches
- Add hotplug support for R6 processors
- Cleanup hotplug bits in kconfig
- traps: return correct si code for accessing nonmapped addresses
- Remove cpu_has_safe_index_cacheops
Lantiq:
- Register IRQ handler for virtual IRQ number
- Fix EIU interrupt loading code
- Use the real EXIN count
- Fix build error.
Loongson 3:
- Increase HPET_MIN_PROG_DELTA and decrease HPET_MIN_CYCLES
Octeon:
- Delete built-in DTB pruning code for D-Link DSR-1000N.
- Clean up GPIO definitions in dlink_dsr-1000n.dts.
- Add more LEDs to the DSR-100n DTS
- Fix off by one in octeon_irq_gpio_map()
- Typo fixes
- Enable SATA by default in cavium_octeon_defconfig
- Support readq/writeq()
- Remove forced mappings of USB interrupts.
- Ensure DMA descriptors are always in the low 4GB
- Improve USB reset code for OCTEON II.
Pistachio:
- Add maintainers entry for pistachio SoC Support
- Remove plat_setup_iocoherency
Ralink:
- Fix pwm UART in spis group pinmux.
SSB:
- Change bare unsigned to unsigned int to suit coding style
Tools:
- Fix reloc tool compiler warnings.
Other:
- Delete use of ARCH_WANT_OPTIONAL_GPIOLIB"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (61 commits)
MIPS: mm: Fix definition of R6 cache instruction
MIPS: tools: Fix relocs tool compiler warnings
MIPS: Cobalt: Fix typo
MIPS: Octeon: Fix typo
MIPS: Lantiq: Fix build failure
MIPS: Use CPHYSADDR to implement mips32 __pa
MIPS: Octeon: Dlink_dsr-1000n.dts: add more leds.
MIPS: Octeon: Clean up GPIO definitions in dlink_dsr-1000n.dts.
MIPS: Octeon: Delete built-in DTB pruning code for D-Link DSR-1000N.
MIPS: store the appended dtb address in a variable
MIPS: ZBOOT: copy appended dtb to the end of the kernel
MIPS: ralink: fix spis group pinmux
MIPS: Factor o32 specific code into signal_o32.c
MIPS: non-exec stack & heap when non-exec PT_GNU_STACK is present
MIPS: Use per-mm page to execute branch delay slot instructions
MIPS: Modify error handling
MIPS: c-r4k: Use SMP calls for CM indexed cache ops
MIPS: c-r4k: Avoid small flush_icache_range SMP calls
MIPS: c-r4k: Local flush_icache_range cache op override
MIPS: c-r4k: Split r4k_flush_kernel_vmap_range()
...
find_vma() returns the first VMA which satisfies fault_addr < vm_end, but
it does not guarantee fault_addr is actually within VMA. Therefore, kernel
has to check that before it chooses correct si code on return.
Signed-off-by: Petar Jovanovic <petar.jovanovic@rt-rk.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13808/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
KVM modifies CP0_HWREna during guest execution so it can trap and
emulate RDHWR instructions, however it always restores the hardcoded
value 0x2000000F. This assumes the presence of the UserLocal register,
and the absence of any implementation dependent or future HW registers.
Fix by exporting the value that traps.c write into CP0_HWREna, and
loading from there instead of hard coding.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
No preprocessor definitions are used in the handling of the registers
accessible with the RDHWR instruction, nor the corresponding bits in the
CP0 HWREna register.
Add definitions for both the register numbers (MIPS_HWR_*) and HWREna
bits (MIPS_HWRENA_*) in asm/mipsregs.h and make use of them in the
initialisation of HWREna and emulation of the RDHWR instruction.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: David Daney <david.daney@cavium.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The host kernel's exception vector base address is currently saved in
the VCPU structure at creation time, and restored on a guest exit.
However it doesn't change and can already be easily accessed from the
'ebase' variable (arch/mips/kernel/traps.c), so drop the host_ebase
member of kvm_vcpu_arch, export the 'ebase' variable to modules and load
from there instead.
This does result in a single extra instruction (lui) on the guest exit
path, but simplifies the code a bit and removes the redundant storage of
the host exception base address.
Credit for the idea goes to Cavium's VZ KVM implementation.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Fix a build regression from commit c9017757c5 ("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 <macro@imgtec.com>
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 <ralf@linux-mips.org>
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 <paul.burton@imgtec.com>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13210/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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 <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12728/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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 <paul.burton@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Joshua Kinard <kumba@gentoo.org>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Petri Gynther <pgynther@google.com>
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 <ralf@linux-mips.org>
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 <markos.chandras@imgtec.com>
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Petri Gynther <pgynther@google.com>
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12328/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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 <aaro.koskinen@iki.fi>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
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 <ralf@linux-mips.org>
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 <james.hogan@imgtec.com>
Reviewed-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 3.15+
Patchwork: https://patchwork.linux-mips.org/patch/11701/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit d2941a975ac745c607dfb590e92bb30bc352dad9)
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 <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12282/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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>
Avoid sending a partially initialised `siginfo_t' structure along SIGFPE
signals issued from `do_ov' and `do_trap_or_bp', leading to information
leaking from the kernel stack.
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: stable@vger.kernel.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Fix the code to fetch and decode the whole 32-bit instruction. This
only really matters with the `noulri' kernel parameter as all microMIPS
processors are supposed to have all the hardware registers we support.
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12281/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
In the regular MIPS instruction set RDHWR is encoded with the SPECIAL3
(011111) major opcode. Therefore it cannot trigger the CpU (Coprocessor
Unusable) exception, and certainly not for coprocessor 0, as the opcode
does not overlap with any of the older ISA reservations, i.e. LWC0
(110000), SWC0 (111000), LDC0 (110100) or SDC0 (111100). The closest
match might be SDC3 (111111), possibly causing a CpU #3 exception,
however our code does not handle it anyway. A quick check with a MIPS I
and a MIPS III processor:
CPU0 revision is: 00000220 (R3000)
CPU0 revision is: 00000440 (R4400SC)
indeed indicates that the RI (Reserved Instruction) exception is
triggered. It's only LL and SC that require emulation in the CpU #0
exception handler as they reuse the LWC0 and SWC0 opcodes respectively.
In the microMIPS instruction set RDHWR is mandatory and triggering the
RI exception is required on unimplemented or disabled register accesses.
Therefore emulating the microMIPS instruction in the CpU #0 exception
handler is not required either.
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12280/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The first argument to set_except_vector is the ExcCode, which we now
have definitions for. Lets make use of them.
Signed-off-by: James Hogan <james.hogan@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
Patchwork: https://patchwork.linux-mips.org/patch/11894/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Rather than #ifdef on CONFIG_KVM_GUEST & redefine the guest kseg0 base
locally, make use of the CAC_BASE macro which has the correct value in
both cases.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-kernel@vger.kernel.org
Cc: Markos Chandras <markos.chandras@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/11183/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The TLB registers are dumped in a couble of places:
- sysrq_tlbdump_single() - when dumping TLB state.
- do_mcheck() - in response to a machine check error.
The main TLB registers also differ between r3k and r4k, but r4k appears
to be assumed.
Refactor this code into a dump_tlb_regs() function, implemented for both
r3k and r4k, and used by both of the above functions.
Fixes: d1e9a4f547 ("MIPS: Add SysRq operation to dump TLBs on all CPUs")
Suggested-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10721/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add a CPU_I6400 case to various switch statements, doing the same thing
as for CPU_P5600.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10635/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The show_stack() function deals exclusively with kernel contexts, but if
it gets called in user context with EVA enabled, show_stacktrace() will
attempt to access the stack using EVA accesses, which will either read
other user mapped data, or more likely cause an exception which will be
handled by __get_user().
This is easily reproduced using SysRq t to show all task states, which
results in the following stack dump output:
Stack : (Bad stack address)
Fix by setting the current user access mode to kernel around the call to
show_stacktrace(). This causes __get_user() to use normal loads to read
the kernel stack.
Now we get the correct output, like this:
Stack : 00000000 80168960 00000000 004a0000 00000000 00000000 8060016c 1f3abd0c
1f172cd8 8056f09c 7ff1e450 8014fc3c 00000001 806dd0b0 0000001d 00000002
1f17c6a0 1f17c804 1f17c6a0 8066f6e0 00000000 0000000a 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 0110e800 1f3abd6c 1f17c6a0
...
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 3.15+
Patchwork: https://patchwork.linux-mips.org/patch/10778/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
If a machine check exception is raised in kernel mode, user context,
with EVA enabled, then the do_mcheck handler will attempt to read the
code around the EPC using EVA load instructions, i.e. as if the reads
were from user mode. This will either read random user data if the
process has anything mapped at the same address, or it will cause an
exception which is handled by __get_user, resulting in this output:
Code: (Bad address in epc)
Fix by setting the current user access mode to kernel if the saved
register context indicates the exception was taken in kernel mode. This
causes __get_user to use normal loads to read the kernel code.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 3.15+
Patchwork: https://patchwork.linux-mips.org/patch/10777/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Commit 854700115ecf ([MIPS] kgdb: add arch support for the kernel's kgdb core)
added the 'kgdb_early_setup' flag to avoid calling trap_init() and init_IRQ()
the second time, however the code that called these functions earlier, from
kgdb_arch_init(), had been already removed by that time, so the flag never
served any useful purpose. Remove the related code along with ugly #ifdef'ery
at last.
[ralf@linux-mips.org: Folded in Guenter Roeck's fix.]
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Patchwork: https://patchwork.linux-mips.org/patch/10501/
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Patchwork: https://patchwork.linux-mips.org/patch/10533/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
__show_regs() calls show_regs_print_info(), which already outputs
the Tainted: information. So, no need to output it twice.
Signed-off-by: Petri Gynther <pgynther@google.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9997/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
functions, prompted by their mis-use in staging.
With these function removed, all cpu functions should only iterate to
nr_cpu_ids, so we finally only allocate that many bits when cpumasks
are allocated offstack.
Thanks,
Rusty.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
iQIcBAABAgAGBQJVNPMuAAoJENkgDmzRrbjx7ZIP/j65e6xs1jEyXR3WOYSdTU1x
bMo6JcII6O1oEZLgyKXgx9KiBg6uIIDta1NG/H/XIe354dwfHVsHvj5HHHQR5Xof
iRrjLOaHj4XglI3hvsk0eEEl3/OBBLgyo9bUwDvMF1fmr/9tW4caMs3Op6n7Evzm
YIvoAyeJ0A8BfEtOU5lXhcVIGmnHtSw0x6mdGXpXIBmWYQPCtdQP868s4lnl44w0
bSNpAYdzEqg64Ph3SK0prgWPrn5+5EiaAhV7HZzENZ5+o0DAdIXWq/W7uHyCWPKH
536cJDojec+nSUQkPYngngGprxrKO02aBcMw/3JGJ0tdCDj8yw3XAyVAFzz4hmMb
Lkmyv4QHHIILLvJ4ZRH5KHWCjjVBg41LNCs2H3HnoxFACdm0lZYKHsUAh2ucBVtU
Wb/eHmLxOG43UIkpX4yrhy3SfE1ZdnOVzEzOzPXtr51t8ojqk+bLFe/hJ6EkzrQX
X+90qHfBq+PMJlAnc3zdXHjxoJrL6KPWVwVvFrNeibgEKtVvy/BiwZkS6QceC1Ea
TatOYA5r6awFVHHQCooN1DGAxN5Juvu2SmdnTUA9ymsCNDghj1YUoAKRNP81u8Sa
pe3hco/63iCuPna+vlwNDU6SgsaMk9m0p+1n1BiDIfVJIkWYCNeG+u2gQkzbDKlQ
AJuKKQv1QuZiF0ylZ0wq
=VAgA
-----END PGP SIGNATURE-----
Merge tag 'cpumask-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull final removal of deprecated cpus_* cpumask functions from Rusty Russell:
"This is the final removal (after several years!) of the obsolete
cpus_* functions, prompted by their mis-use in staging.
With these function removed, all cpu functions should only iterate to
nr_cpu_ids, so we finally only allocate that many bits when cpumasks
are allocated offstack"
* tag 'cpumask-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (25 commits)
cpumask: remove __first_cpu / __next_cpu
cpumask: resurrect CPU_MASK_CPU0
linux/cpumask.h: add typechecking to cpumask_test_cpu
cpumask: only allocate nr_cpumask_bits.
Fix weird uses of num_online_cpus().
cpumask: remove deprecated functions.
mips: fix obsolete cpumask_of_cpu usage.
x86: fix more deprecated cpu function usage.
ia64: remove deprecated cpus_ usage.
powerpc: fix deprecated CPU_MASK_CPU0 usage.
CPU_MASK_ALL/CPU_MASK_NONE: remove from deprecated region.
staging/lustre/o2iblnd: Don't use cpus_weight
staging/lustre/libcfs: replace deprecated cpus_ calls with cpumask_
staging/lustre/ptlrpc: Do not use deprecated cpus_* functions
blackfin: fix up obsolete cpu function usage.
parisc: fix up obsolete cpu function usage.
tile: fix up obsolete cpu function usage.
arm64: fix up obsolete cpu function usage.
mips: fix up obsolete cpu function usage.
x86: fix up obsolete cpu function usage.
...
Pull MIPS updates from Ralf Baechle:
"This is the main pull request for MIPS for Linux 4.1. Most
noteworthy:
- Add more Octeon-optimized crypto functions
- Octeon crypto preemption and locking fixes
- Little endian support for Octeon
- Use correct CSR to soft reset Octeons
- Support LEDs on the Octeon-based DSR-1000N
- Fix PCI interrupt mapping for the Octeon-based DSR-1000N
- Mark prom_free_prom_memory() as __init for a number of systems
- Support for Imagination's Pistachio SOC. This includes arch and
CLK bits. I'd like to merge pinctrl bits later
- Improve parallelism of csum_partial for certain pipelines
- Organize DTB files in subdirs like other architectures
- Implement read_sched_clock for all MIPS platforms other than
Octeon
- Massive series of 38 fixes and cleanups for the FPU emulator /
kernel
- Further FPU remulator work to support new features. This sits on a
separate branch which also has been pulled into the 4.1 KVM branch
- Clean up and fixes for the SEAD3 eval board; remove unused file
- Various updates for Netlogic platforms
- A number of small updates for Loongson 3 platforms
- Increase the memory limit for ATH79 platforms to 256MB
- A fair number of fixes and updates for BCM47xx platforms
- Finish the implementation of XPA support
- MIPS FDC support. No, not floppy controller but Fast Debug Channel :)
- Detect the R16000 used in SGI legacy platforms
- Fix Kconfig dependencies for the SSB bus support"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (265 commits)
MIPS: Makefile: Fix MIPS ASE detection code
MIPS: asm: elf: Set O32 default FPU flags
MIPS: BCM47XX: Fix detecting Microsoft MN-700 & Asus WL500G
MIPS: Kconfig: Disable SMP/CPS for 64-bit
MIPS: Hibernate: flush TLB entries earlier
MIPS: smp-cps: cpu_set FPU mask if FPU present
MIPS: lose_fpu(): Disable FPU when MSA enabled
MIPS: ralink: add missing symbol for RALINK_ILL_ACC
MIPS: ralink: Fix bad config symbol in PCI makefile.
SSB: fix Kconfig dependencies
MIPS: Malta: Detect and fix bad memsize values
Revert "MIPS: Avoid pipeline stalls on some MIPS32R2 cores."
MIPS: Octeon: Delete override of cpu_has_mips_r2_exec_hazard.
MIPS: Fix cpu_has_mips_r2_exec_hazard.
MIPS: kernel: entry.S: Set correct ISA level for mips_ihb
MIPS: asm: spinlock: Fix addiu instruction for R10000_LLSC_WAR case
MIPS: r4kcache: Use correct base register for MIPS R6 cache flushes
MIPS: Kconfig: Fix typo for the r2-to-r6 emulator kernel parameter
MIPS: unaligned: Fix regular load/store instruction emulation for EVA
MIPS: unaligned: Surround load/store macros in do {} while statements
...
Rework `process_fpemu_return' and move IEEE 754 exception interpretation
there, from `do_fpe'. Record the cause bits set in FCSR before they are
cleared and pass them through to `process_fpemu_return' so as to set
`si_code' correctly too for SIGFPE signals sent from emulation rather
than those issued by hardware with the FPE processor exception only.
For simplicity `mipsr2_decoder' assumes `*fcr31' has been preinitialised
and only sets it to anything if an FPU instruction has been emulated,
which in turn is the only case SIGFPE can be issued for here.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9705/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Clear any FCSR cause bits recorded in the saved FPU context after
emulation in all cases rather than in `do_fpe' only, so that any
unmasked IEEE 754 exception left from emulation does not cause a fatal
kernel-mode FPE hardware exception with the CTC1 instruction used by the
kernel to subsequently restore FCSR hardware from the saved FPU context.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9704/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Respect the FCSR exception mask when interpreting the IEEE 754 exception
condition to report with SIGFPE in `si_code', so as not to use one that
has been masked where a different one set in parallel caused the FPE
hardware exception to trigger. As per the IEEE Std 754 the Inexact
exception can happen together with Overflow or Underflow.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9703/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Correct ISA requirements for floating-point instructions:
* the CU3 exception signifies a real COP3 instruction in MIPS I & II,
* the BC1FL and BC1TL instructions are not supported in MIPS I,
* the SQRT.fmt instructions are indeed supported in MIPS II,
* the LDC1 and SDC1 instructions are indeed supported in MIPS32r1,
* the CEIL.W.fmt, FLOOR.W.fmt, ROUND.W.fmt and TRUNC.W.fmt instructions
are indeed supported in MIPS32,
* the CVT.L.fmt and CVT.fmt.L instructions are indeed supported in
MIPS32r2 and MIPS32r6,
* the CEIL.L.fmt, FLOOR.L.fmt, ROUND.L.fmt and TRUNC.L.fmt instructions
are indeed supported in MIPS32r2 and MIPS32r6,
* the RSQRT.fmt and RECIP.fmt instructions are indeed supported in
MIPS64r1,
Also simplify conditionals for MIPS III and MIPS IV FPU instructions and
the handling of the MOVCI minor opcode.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9700/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Do not lose the other half of the BREAK code where there is an upper
half. This is so that e.g. `BREAK 7, 7' is not interpreted as a divide
by zero trap, while `BREAK 0, 7' or `BREAK 7, 0' still are.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9697/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add the missing microMIPS BREAK16 instruction code interpretation and
reshape code removing instruction fetching duplication and the separate
call to `do_trap_or_bp' in the MIPS16 path.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9696/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Correct the interpretation of the immediate MIPS16 BREAK instruction
code embedded in the instruction word across bits 10:5 rather than 11:6
as current code implies, fixing the interpretation of integer overflow
and divide by zero traps.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9695/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Changes applied to `do_cpu' over time reduced the use of the SIGILL
issued with `force_sig' at the end to a single CU3 case only in the
switch statement there. Move that `force_sig' call over to right where
required then and toss out the pile of gotos now not needed to skip over
the call, replacing them with regular breaks out of the switch.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9683/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Fold a nested `if' statement for the R6 case in `do_ri' into its
containing `if' block, removing excessive indentation causing code to
extend beyond 79 columns.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9679/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Adjust the explanatory comment for FPU emulator traps according to
ba3049ed [MIPS: Switch FPU emulator trap to BREAK instruction.];
originally coming from `do_ade'.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9672/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Read the CPU IRQ line reportedly used for the Fast Debug Channel (FDC)
interrupt from the IntCtl register and store it in cp0_fdc_irq where
platform implementations of the new weak platform function
get_c0_fdc_int() can refer to it.
[ralf@linux-mips.org: Fixed conflict.]
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: James Hogan <james.hogan@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/9140/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Before release 2 of the architecture there weren't separate interrupt
pending bits for the local CPU interrupts (timer & perf counter
overflow), so when they were connected to the same interrupt line the
timer handler had to call the performance counter handler before knowing
whether a timer interrupt was actually pending.
Now another CPU local interrupt, for the Fast Debug Channel (FDC), can
also be routed to an arbitrary interrupt line. It isn't scalable to keep
adding cross-calls between handlers for these cases of shared interrupt
lines, especially since the FDC could in theory share its interrupt line
with the performance counter, timer, or both.
Fortunately since release 2 of the architecture separate interrupt
pending bits do exist in the Cause register. This allows local
interrupts which share an interrupt line to have separate handlers using
IRQF_SHARED. Unfortunately they can't easily have their own irqchip as
there is no generic way to individually mask them.
Enable this sharing to happen by removing the special case for when the
perf count shares an IRQ with the timer. cp0_perfcount_irq and
cp0_compare_irq can then be set to the same value with shared interrupt
handlers registered for both of them.
Pre-R2 code should be unaffected. cp0_perfcount_irq will always be -1
and the timer handler will contnue to call into the perf counter
handler.
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/9131/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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
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>
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
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
...
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>
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>
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>
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>
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>
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>
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>
Preemption must be disabled throughout the process of enabling the FPU,
enabling MSA & initialising the vector registers. Without doing so it
is possible to lose the FPU or MSA whilst initialising them causing
that initialisation to fail.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7307/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
If a task does not execute scalar FP instructions prior to using MSA
then the flags indicating that the task has live MSA context were not
being set. The upper 64b of each vector register would then be lost
upon the tasks first context switch after using MSA.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7500/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
When a task first makes use of MSA we need to ensure that the upper
64b of the vector registers are set to some value such that no
information can be leaked to it from the previous task to use MSA
context on the CPU. The architecture formerly specified that these
bits would be cleared to 0 when a scalar FP instructions wrote to the
aliased FP registers, which would have implicitly handled this as the
kernel restored scalar FP context. However more recent versions of the
specification now state that the value of the bits in such cases is
unpredictable. Initialise them explictly to be sure, and set all the
bits to 1 rather than 0 for consistency with the least significant
64b.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7497/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Switching the vector context implicitly saves & restores the state of
the aliased scalar FP data registers, however the scalar FP control
& status register is distinct from the MSA control & status register.
In order to allow scalar FP to function correctly in programs using
MSA, the scalar CSR needs to be saved & restored along with the MSA
vector context.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7301/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Use the regular tlb_do_page_fault_0 (no write) handler to handle
the RI and XI exceptions. Also skip the RI/XI validation check
on TLB load handler since it's redundant when the CPU has
unique RI/XI exceptions.
Singed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7339/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Performing vma lookups without taking the mm->mmap_sem is asking
for trouble. While doing the search, the vma in question can be
modified or even removed before returning to the caller. Take the
lock (exclusively) in order to avoid races while iterating through
the vmacache and/or rbtree.
Updates two functions:
- process_fpemu_return()
- cteon_flush_cache_sigtramp()
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Tested-by: Andreas Herrmann <andreas.herrmann@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Cc: akpm@linux-foundation.org
Cc: zeus@gnu.org
Cc: aswin@hp.com
Cc: davidlohr@hp.com
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
Patchwork: http://patchwork.linux-mips.org/patch/6811/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Introduced by the following two commits:
75b5b5e0a2
"MIPS: Add support for FTLBs"
6de2045185
"MIPS: Add printing of ES bit for Imgtec cores when cache error occurs"
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Reported-by: Matheus Almeida <Matheus.Almeida@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: stable@vger.kernel.org # v3.14+
Patchwork: https://patchwork.linux-mips.org/patch/6980/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Nobody is maintaining SMTC anymore and there also seems to be no userbase.
Which is a pity - the SMTC technology primarily developed by Kevin D.
Kissell <kevink@paralogos.com> is an ingenious demonstration for the MT
ASE's power and elegance.
Based on Markos Chandras <Markos.Chandras@imgtec.com> patch
https://patchwork.linux-mips.org/patch/6719/ which while very similar did
no longer apply cleanly when I tried to merge it plus some additional
post-SMTC cleanup - SMTC was a feature as tricky to remove as it was to
merge once upon a time.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Implement a CPU power management callback for restoring trap related CPU
configuration after CPU power up from a low power state. The following
state is restored:
- Status register
- HWREna register
- Exception vector configuration registers
- Context/XContext register
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
When a breakpoint or trap happens when operating in kernel mode but
on users behalf (eg syscall) it is necessary to change the address
limit to KERNEL_DS so any address checking can be bypassed and print
the correct stack trace.
Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Add a CPU_P5600 case to various switch statements, doing the same thing
as for CPU_PROAPTIV.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6408/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This patch adds a simple handler for MSA FP exceptions which delivers a
SIGFPE to the running task. In the future it should probably be extended
to re-execute the instruction with the MSACSR.NX bit set in order to
generate results for any elements which did not cause an exception
before delivering the SIGFPE signal.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6432/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This patch adds support for context switching the MSA vector registers.
These 128 bit vector registers are aliased with the FP registers - an
FP register accesses the least significant bits of the vector register
with which it is aliased (ie. the register with the same index). Due to
both this & the requirement that the scalar FPU must be 64-bit (FR=1) if
enabled at the same time as MSA the kernel will enable MSA & scalar FP
at the same time for tasks which use MSA. If we restore the MSA vector
context then we might as well enable the scalar FPU since the reason it
was left disabled was to allow for lazy FP context restoring - but we
just restored the FP context as it's a subset of the vector context. If
we restore the FP context and have previously used MSA then we have to
restore the whole vector context anyway (see comment in
enable_restore_fp_context for details) so similarly we might as well
enable MSA.
Thus if a task does not use MSA then it will continue to behave as
without this patch - the scalar FP context will be saved & restored as
usual. But if a task executes an MSA instruction then it will save &
restore the vector context forever more.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6431/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The 1074K is a multiprocessing coherent processing system (CPS) based
on modified 74K cores. This patch makes the 1074K an actual unique
CPU type, instead of a 74K derivative, which it is not.
Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
Reviewed-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6389/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The interAptiv is a power-efficient multi-core microprocessor
for use in system-on-chip (SoC) applications. The interAptiv combines
a multi-threading pipeline with a coherence manager to deliver improved
computational throughput and power efficiency. The interAptiv can
contain one to four MIPS32R3 interAptiv cores, system level
coherence manager with L2 cache, optional coherent I/O port,
and optional floating point unit.
Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/6163/
The Fixed Page Size TLB (FTLB) is a set-associative dual entry TLB. Its
purpose is to reduce the number of TLB misses by increasing the effective
TLB size and keep the implementation complexity to minimum levels.
A supported core can have both VTLB and FTLB.
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/6139/
The proAptiv Multiprocessing System is a power efficient multi-core
microprocessor for use in system-on-chip (SoC) applications.
The proAptiv Multiprocessing System combines a deep pipeline
with multi-issue out of order execution for improved computational
throughput. The proAptiv Multiprocessing System can contain one to
six MIPS32r3 proAptiv cores, system level coherence
manager with L2 cache, optional coherent I/O port, and optional
floating point unit.
Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/6134/
The cacheer register is always implemented in the same way in the
MIPS32r2 Imgtec cores so print the ES bit when an cache error
occurs.
Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/6041/
CPUs implementing MIPS32 R2 may include a 64-bit FPU, just as MIPS64 CPUs
do. In order to preserve backwards compatibility a 64-bit FPU will act
like a 32-bit FPU (by accessing doubles from the least significant 32
bits of an even-odd pair of FP registers) when the Status.FR bit is
zero, again just like a mips64 CPU. The standard O32 ABI is defined
expecting a 32-bit FPU, however recent toolchains support use of a
64-bit FPU from an O32 MIPS32 executable. When an ELF executable is
built to use a 64-bit FPU a new flag (EF_MIPS_FP64) is set in the ELF
header.
With this patch the kernel will check the EF_MIPS_FP64 flag when
executing an O32 binary, and set Status.FR accordingly. The addition
of O32 64-bit FP support lessens the opportunity for optimisation in
the FPU emulator, so a CONFIG_MIPS_O32_FP64_SUPPORT Kconfig option is
introduced to allow this support to be disabled for those that don't
require it.
Inspired by an earlier patch by Leonid Yegoshin, but implemented more
cleanly & correctly.
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/6154/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
An NMI exception delivered from YAMON delivers the PC in ErrorPC
instead of EPC. It's also necessary to clear the Status.BEV
bit for the page fault exception handler to work properly.
[ralf@linux-mips: Let the assembler do the loading of the mask value rather
than the convoluted explicit %hi/%lo manual relocation sequence from the
original patch.]
Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6035/
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Markos Chandras <markos.chandras@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/6084/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Checking for n<0 && n>9 makes no sense because it can never
be true. Moreover, we can have up to 64 vectored interrupts
so BUG_ON(n>9) was wrong anyway.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Acked-by: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5909/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
o Move current_cpu_type() to a separate header file
o #ifdefing on supported CPU types lets modern GCC know that certain
code in callers may be discarded ideally turning current_cpu_type() into
a function returning a constant.
o Use current_cpu_type() rather than direct access to struct cpuinfo_mips.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5833/
Pull MIPS fixes from Ralf Baechle:
"MIPS fixes for 3.11. Half of then is for Netlogic the remainder
touches things across arch/mips.
Nothing really dramatic and by rc1 standards MIPS will be in fairly
good shape with this applied. Tested by building all MIPS defconfigs
of which with this pull request four platforms won't build. And yes,
it boots also on my favorite test systems"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
MIPS: kvm: Kconfig: Drop HAVE_KVM dependency from VIRTUALIZATION
MIPS: Octeon: Fix DT pruning bug with pip ports
MIPS: KVM: Mark KVM_GUEST (T&E KVM) as BROKEN_ON_SMP
MIPS: tlbex: fix broken build in v3.11-rc1
MIPS: Netlogic: Add XLP PIC irqdomain
MIPS: Netlogic: Fix USB block's coherent DMA mask
MIPS: tlbex: Fix typo in r3000 tlb store handler
MIPS: BMIPS: Fix thinko to release slave TP from reset
MIPS: Delete dead invocation of exception_exit().
panic() doesn't return so this call was useless.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Reported-by: Alexander Sverdlin <alexander.sverdlin@nsn.com>
commit 3747069b25e419f6b51395f48127e9812abc3596 upstream.
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications. For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.
After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out. Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.
Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
and are flagged as __cpuinit -- so if we remove the __cpuinit from
the arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
related content into no-ops as early as possible, since that will get
rid of these warnings. In any case, they are temporary and harmless.
Here, we remove all the MIPS __cpuinit from C code and __CPUINIT
from asm files. MIPS is interesting in this respect, because there
are also uasm users hiding behind their own renamed versions of the
__cpuinit macros.
[1] https://lkml.org/lkml/2013/5/20/589
[ralf@linux-mips.org: Folded in Paul's followup fix.]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5494/
Patchwork: https://patchwork.linux-mips.org/patch/5495/
Patchwork: https://patchwork.linux-mips.org/patch/5509/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The ISA exception bit selects whether exceptions are taken in classic
or microMIPS mode. This bit is Config3.ISAOnExc and was improperly
defined as bits 16 and 17 instead of just bit 16. A new function was
added so that platforms could set this bit when running a kernel
compiled with only microMIPS instructions.
Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5377/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
MIPS I is the ancestor of all MIPS ISA and architecture variants. Anything
ever build in the MIPS empire is either MIPS I or at least contains MIPS I.
If it's running Linux, that is.
So there is little point in having cpu_has_mips_1 because it will always
evaluate as true - though usually only at runtime. Thus there is no
point in having the MIPS_CPU_ISA_I ISA flag, so get rid of it.
Little complication: traps.c was using a test for a pure MIPS I ISA as
a test for an R3000-style cp0. To deal with that, use a check for
cpu_has_3kex or cpu_has_4kex instead.
cpu_has_3kex is a new macro. At the moment its default implementation is
!cpu_has_4kex but this may eventually change if Linux is ever going to
support the oddball MIPS processors R6000 and R8000 so users of either
of these macros should not make any assumptions.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/5551/
When having enabled MIPS_PGD_C0_CONTEXT, trap_init() might call the
generated tlbmiss_handler_setup_pgd before it was committed to memory,
causing boot failures:
trap_init()
|- per_cpu_trap_init()
| |- TLBMISS_HANDLER_SETUP()
| |- tlbmiss_handler_setup_pgd()
|- flush_tlb_handlers()
To avoid this, move flush_tlb_handlers() into build_tlb_refill_handler()
right after they were generated. We can do this as the cache handling is
initialized just before creating the tlb handlers.
This issue was introduced in 3d8bfdd030
("MIPS: Use C0_KScratch (if present) to hold PGD pointer.").
Signed-off-by: Jonas Gorski <jogo@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Jayachandran C <jchandra@broadcom.com>
Cc: David Daney <david.daney@cavium.com>
Patchwork: https://patchwork.linux-mips.org/patch/5539/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Kernel threads should be able to use COP2 if the platform needs it.
Do not call die_if_kernel() for a coprocessor unusable exception if
the exception due to COP2 usage. Instead, the default notifier for
COP2 exceptions is updated to call die_if_kernel.
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Cc: linux-mips@linux-mips.org
Cc: ddaney.cavm@gmail.com
Patchwork: https://patchwork.linux-mips.org/patch/5415/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Matt Redfearn