James Hogan [Wed, 18 May 2016 16:04:38 +0000 (17:04 +0100)]
MIPS: Fix write_gc0_* macros when writing zero
The versions of the __write_{32,64}bit_gc0_register() macros for when
there is no virt support in the assembler use the "J" inline asm
constraint to allow integer zero, but this needs to be accompanied by
the "z" formatting string so that it turns into $0. Fix both macros to
do this.
Fixes: bad50d79255a ("MIPS: Fix VZ probe gas errors with binutils <2.24") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13289/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Matt Redfearn [Wed, 18 May 2016 16:12:36 +0000 (17:12 +0100)]
MIPS: CPS: Copy EVA configuration when starting secondary VPs.
When starting secondary VPEs which support EVA and the SegCtl registers,
copy the memory segmentation configuration from the running VPE to ensure
that all VPEs in the core have a consistent virtual memory map.
The EVA configuration of secondary cores is dealt with when starting the
core via the CM.
Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13291/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
James Hogan [Tue, 17 May 2016 23:08:49 +0000 (00:08 +0100)]
MIPS: Fix incomplete separation of XPA CPU feature
Commit 12822570a29b ("MIPS: Separate XPA CPU feature into LPA and MVH")
wasn't fully applied, possibly due to a conflict with commit f270d881fa55 ("MIPS: Detect MIPSr6 Virtual Processor support"). This
left decode_config5() referring to the non-existent MIPS_CPU_XPA, which
breaks the build when XPA is enabled:
arch/mips/kernel/cpu-probe.c In function ‘decode_config5’:
arch/mips/kernel/cpu-probe.c:838:17: error: ‘MIPS_CPU_XPA’ undeclared (first use in this function)
c->options |= MIPS_CPU_XPA;
^
Apply the missing hunk, dropping the CONFIG_XPA ifdef and setting the
MIPS_CPU_MVH option when Config5.MVH is set.
Fixes: 12822570a29b ("MIPS: Separate XPA CPU feature into LPA and MVH") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Link: https://patchwork.linux-mips.org/patch/13112/
Patchwork: https://patchwork.linux-mips.org/patch/13277/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Paul Burton [Tue, 17 May 2016 14:31:06 +0000 (15:31 +0100)]
irqchip: mips-gic: Setup EIC mode on each CPU if it's in use
When EIC mode is in use (cpu_has_veic is true) enable it on each CPU
during GIC initialisation. Otherwise there may be a mismatch between the
hardware default interrupt model & that expected by the kernel.
Signed-off-by: Paul Burton <paul.burton@imgtec.com> Reviewed-by: Matt Redfearn <matt.redfearn@imgtec.com> Tested-by: Matt Redfearn <matt.redfearn@imgtec.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Jason Cooper <jason@lakedaemon.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13274/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Paul Burton [Tue, 17 May 2016 14:31:05 +0000 (15:31 +0100)]
MIPS: smp-cps: Clear Status IPL field when using EIC
When using an external interrupt controller (EIC) the interrupt mask
bits in the cop0 Status register are reused for the Interrupt Priority
Level, and any interrupts with a priority lower than the field will be
ignored. Clear the field to 0 by default such that all interrupts are
serviced.
Signed-off-by: Paul Burton <paul.burton@imgtec.com> Reviewed-by: Matt Redfearn <matt.redfearn@imgtec.com> Tested-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Qais Yousef <qsyousef@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13273/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Paul Burton [Tue, 17 May 2016 14:31:04 +0000 (15:31 +0100)]
MIPS: Clear Status IPL field when using EIC
When using an external interrupt controller (EIC) the interrupt mask
bits in the cop0 Status register are reused for the Interrupt Priority
Level, and any interrupts with a priority lower than the field will be
ignored. Clear the field to 0 by default such that all interrupts are
serviced. Without doing so we default to arbitrarily ignoring all or
some subset of interrupts.
Signed-off-by: Paul Burton <paul.burton@imgtec.com> Reviewed-by: Matt Redfearn <matt.redfearn@imgtec.com> Tested-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Cc: Joe Perches <joe@perches.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13272/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
PIC32 clock driver is now implemented as platform driver instead of
as part of of_clk_init(). It meants all the clock modules are available
quite late in the boot sequence. So request for CPU clock by clk_get_sys()
and clk_get_rate() to find c0_timer rate fails.
To fix this use PIC32 specific early clock functions implemented for early
console support.
Felix Fietkau [Mon, 16 May 2016 17:51:54 +0000 (19:51 +0200)]
MIPS: ath79: make ath79_ddr_ctrl_init() compatible for newer SoCs
AR913x, AR724x and AR933x are the only SoCs where the
ath79_ddr_wb_flush_base starts at 0x7c, all newer SoCs use 0x9c
Invert the logic to make the code compatible with AR95xx
James Hogan [Mon, 16 May 2016 11:50:04 +0000 (12:50 +0100)]
MIPS: Fix VZ probe gas errors with binutils <2.24
The VZ guest register & TLB access macros introduced in commit "MIPS:
Add guest CP0 accessors" use VZ ASE specific instructions that aren't
understood by versions of binutils prior to 2.24.
Add a check for whether the toolchain supports the -mvirt option,
similar to the MSA toolchain check, and implement the accessors using
.word if not.
Due to difficulty in converting compiler specified registers (e.g. "$3")
to usable numbers (e.g. "3") in inline asm, we need to copy to/from a
temporary register, namely the assembler temporary (at/$1), and specify
guest CP0 registers numerically in the gc0 macros.
James Hogan [Mon, 16 May 2016 18:32:35 +0000 (19:32 +0100)]
MIPS: perf: Fix I6400 event numbers
Fix perf hardware performance counter event numbers for I6400. This core
does not follow the performance event numbering scheme of previous MIPS
cores. All performance counters (both odd and even) are capable of
counting any of the available events.
Fixes: 4e88a8621301 ("MIPS: Add cases for CPU_I6400") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13259/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
MIPS: MSA: Fix a link error on `_init_msa_upper' with older GCC
Fix a build regression from commit c9017757c532 ("MIPS: init upper 64b
of vector registers when MSA is first used"):
arch/mips/built-in.o: In function `enable_restore_fp_context':
traps.c:(.text+0xbb90): undefined reference to `_init_msa_upper'
traps.c:(.text+0xbb90): relocation truncated to fit: R_MIPS_26 against `_init_msa_upper'
traps.c:(.text+0xbef0): undefined reference to `_init_msa_upper'
traps.c:(.text+0xbef0): relocation truncated to fit: R_MIPS_26 against `_init_msa_upper'
to !CONFIG_CPU_HAS_MSA configurations with older GCC versions, which are
unable to figure out that calls to `_init_msa_upper' are indeed dead.
Of the many ways to tackle this failure choose the approach we have
already taken in `thread_msa_context_live'.
[ralf@linux-mips.org: Drop patch segment to junk file.]
Signed-off-by: Maciej W. Rozycki <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>
Tony Wu [Fri, 4 Dec 2015 11:40:00 +0000 (19:40 +0800)]
MIPS: CM: Fix compilation error when !MIPS_CM
Fix mips_cm_lock_other compilation error when MIPS_CM is not selected.
This was introduced in commit 23d5de8efb9a (MIPS: CM: Introduce core-other
locking functions)
Signed-off-by: Tony Wu <tung7970@gmail.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11698/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
James Hogan [Fri, 13 May 2016 18:41:06 +0000 (19:41 +0100)]
MIPS: Fix genvdso error on rebuild
The genvdso program modifies the debug and stripped versions of the
VDSOs in place, and errors if the modification has already taken place.
Unfortunately this means that a rebuild which tries to rerun genvdso to
generate vdso*-image.c without also rebuilding vdso.so.dbg (for example
if genvdso.c is modified) hits a build error like this:
arch/mips/vdso/genvdso 'arch/mips/vdso/vdso.so.dbg' already contains a '.MIPS.abiflags' section
This is fixed by reorganising the rules such that unmodified .so files
have a .raw suffix, and these are copied in the same rule that runs
genvdso on the copies.
I.e. previously we had:
cmd_vdsold:
link objects -> vdso.so.dbg
cmd_genvdso:
strip vdso.so.dbg -> vdso.so
run genvdso -> vdso-image.c
and modify vdso.so.dbg and vdso.so in place
Now we have:
cmd_vdsold:
link objects -> vdso.so.dbg.raw
a new cmd_objcopy based strip rule (inspired by ARM):
strip vdso.so.dbg.raw -> vdso.so.raw
cmd_genvdso:
copy vdso.so.dbg.raw -> vdso.so.dbg
copy vdso.so.raw -> vdso.so
run genvdso -> vdso-image.c
and modify vdso.so.dbg and vdso.so in place
The ohci-platform driver can control the clock, while usb-nop-xceiv
as the PHY can control the vbus regulator. So this JZ4740-specific
glue is not needed anymore.
The DT fragment will select the ohci-platform driver, since that can
handle the JZ4740 OHCI just fine. While I don't have a JZ4740-based
board with anything connected to the USB host controller, I did test
the generic OHCI driver successfully on a JZ4770-based board.
The device is disabled by default; boards that want to use it can
override the "status" property. The mass-production Qi LB60 boards
don't use the USB host controller.
James Hartley [Tue, 19 Apr 2016 14:46:55 +0000 (15:46 +0100)]
MIPS: pistachio: Determine SoC revision during boot
Now that there are different revisions of the Pistachio SoC
in circulation, add this information to the boot log to make
it easier for users to determine which hardware they have.
Signed-off-by: James Hartley <james.hartley@imgtec.com> Signed-off-by: Ionela Voinescu <ionela.voinescu@imgtec.com> Cc: Andrew Bresticker <abrestic@chromium.org> Cc: Jonas Gorski <jogo@openwrt.org> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13130/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
mips: mt7620: fallback to SDRAM when syscfg0 does not have a valid value for the memory type
Mediatek MT7620 SoC has syscfg0 bits where it sets the type of memory being used.
However, sometimes those bits are not set properly (reading "11"). In this case, the SoC assumes SDRAM.
The patch below reflects that.
Paul Burton [Thu, 21 Apr 2016 17:04:53 +0000 (18:04 +0100)]
MIPS: Prevent "restoration" of MSA context in non-MSA kernels
If a kernel doesn't support MSA context (ie. CONFIG_CPU_HAS_MSA=n) then
it will only keep 64 bits per FP register in thread context, and the
calls to set_fpr64 in restore_msa_extcontext will overrun the end of the
FP register context into the FCSR & MSACSR values. GCC 6.x has become
smart enough to detect this & complain like so:
arch/mips/kernel/signal.c: In function 'protected_restore_fp_context':
./arch/mips/include/asm/processor.h:114:17: error: array subscript is above array bounds [-Werror=array-bounds]
fpr->val##width[FPR_IDX(width, idx)] = val; \
~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~
./arch/mips/include/asm/processor.h:118:1: note: in expansion of macro 'BUILD_FPR_ACCESS'
BUILD_FPR_ACCESS(64)
The only way to trigger this code to run would be for a program to set
up an artificial extended MSA context structure following a sigframe &
execute sigreturn. Whilst this doesn't allow a program to write to any
state that it couldn't already, it makes little sense to allow this
"restoration" of MSA context in a system that doesn't support MSA.
Fix this by killing a program with SIGSYS if it tries something as crazy
as "restoring" fake MSA context in this way, also fixing the build error
& allowing for most of restore_msa_extcontext to be optimised out of
kernels without support for MSA.
Signed-off-by: Paul Burton <paul.burton@imgtec.com> Reported-by: Michal Toman <michal.toman@imgtec.com> Fixes: bf82cb30c7e5 ("MIPS: Save MSA extended context around signals") Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi> Cc: James Hogan <james.hogan@imgtec.com> Cc: Michal Toman <michal.toman@imgtec.com> Cc: linux-mips@linux-mips.org Cc: stable <stable@vger.kernel.org> # v4.3+
Patchwork: https://patchwork.linux-mips.org/patch/13164/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Calculate the MIPS clockevent device's min_delta_ns dynamically based on
the time it takes to perform the mips_next_event() sequence.
Virtualisation in particular makes the current fixed min_delta of 0x300
inappropriate under some circumstances, as the CP0_Count and CP0_Compare
registers may be being emulated by the hypervisor, and the frequency may
not correspond directly to the CPU frequency.
We actually use twice the median of multiple 75th percentiles of
multiple measurements of how long the mips_next_event() sequence takes,
in order to fairly efficiently eliminate outliers due to unexpected
hypervisor latency (which would need handling with retries when it
occurs during normal operation anyway).
Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13176/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
James Hogan [Fri, 22 Apr 2016 17:19:15 +0000 (18:19 +0100)]
MIPS: malta-time: Take seconds into account
When estimating the clock frequency based on the RTC, take seconds into
account in case the Update In Progress (UIP) bit wasn't seen. This can
happen in virtual machines (which may get pre-empted by the hypervisor
at inopportune times) with QEMU emulating the RTC (and in fact not
setting the UIP bit for very long), especially on slow hosts such as
FPGA systems and hardware emulators. This results in several seconds
actually having elapsed before seeing the UIP bit instead of just one
second, and exaggerated timer frequencies.
While updating the comments, they're also fixed to match the code in
that the rising edge of the update flag is detected first, not the
falling edge.
The rising edge gives a more precise point to read the counters in a
virtualised system than the falling edge, resulting in a more accurate
frequency.
It does however mean that we have to also wait for the falling edge
before doing the read of the RTC seconds register, otherwise it seems to
be possible in slow hardware emulation to stray into the interval when
the RTC time is undefined during the update (at least 244uS after the
rising edge of the update flag). This can result in both seconds values
reading the same, and it wrapping to 60 seconds, vastly underestimating
the frequency.
Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13174/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
James Hogan [Fri, 22 Apr 2016 17:19:14 +0000 (18:19 +0100)]
MIPS: malta-time: Start GIC count before syncing to RTC
The sampling of the GIC counter on Malta after observing a rising edge
of the RTC update flag differs slightly between the first and second
sample, with the first sample also calling gic_start_count(). The two
samples should really be taken as similarly as possible to get the most
accurate figure, so move the gic_start_count() call before detecting the
rising edge.
Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13173/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Paul Burton [Thu, 21 Apr 2016 11:43:58 +0000 (12:43 +0100)]
MIPS: Force CPUs to lose FP context during mode switches
Commit 9791554b45a2 ("MIPS,prctl: add PR_[GS]ET_FP_MODE prctl options
for MIPS") added support for the PR_SET_FP_MODE prctl, which allows a
userland program to modify its FP mode at runtime. This is most notably
required if dynamic linking leads to the FP mode requirement changing at
runtime from that indicated in the initial executable's ELF header. In
order to avoid overhead in the general FP context restore code, it aimed
to have threads in the process become unable to enable the FPU during a
mode switch & have the thread calling the prctl syscall wait for all
other threads in the process to be context switched at least once. Once
that happens we can know that no thread in the process whose mode will
be switched has live FP context, and it's safe to perform the mode
switch. However in the (rare) case of modeswitches occurring in
multithreaded programs this can lead to indeterminate delays for the
thread invoking the prctl syscall, and the code monitoring for those
context switches was woefully inadequate for all but the simplest cases.
Fix this by broadcasting an IPI if other CPUs may have live FP context
for an affected thread, with a handler causing those CPUs to relinquish
their FPU ownership. Threads will then be allowed to continue running
but will stall on the wait_on_atomic_t in enable_restore_fp_context if
they attempt to use FP again whilst the mode switch is still in
progress. The end result is less fragile poking at scheduler context
switch counts & a more expedient completion of the mode switch.
Signed-off-by: Paul Burton <paul.burton@imgtec.com> Fixes: 9791554b45a2 ("MIPS,prctl: add PR_[GS]ET_FP_MODE prctl options for MIPS") Reviewed-by: Maciej W. Rozycki <macro@imgtec.com> Cc: Adam Buchbinder <adam.buchbinder@gmail.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: stable <stable@vger.kernel.org> # v4.0+ Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13145/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Paul Burton [Thu, 21 Apr 2016 11:43:57 +0000 (12:43 +0100)]
MIPS: Disable preemption during prctl(PR_SET_FP_MODE, ...)
Whilst a PR_SET_FP_MODE prctl is performed there are decisions made
based upon whether the task is executing on the current CPU. This may
change if we're preempted, so disable preemption to avoid such changes
for the lifetime of the mode switch.
Signed-off-by: Paul Burton <paul.burton@imgtec.com> Fixes: 9791554b45a2 ("MIPS,prctl: add PR_[GS]ET_FP_MODE prctl options for MIPS") Reviewed-by: Maciej W. Rozycki <macro@imgtec.com> Tested-by: Aurelien Jarno <aurelien@aurel32.net> Cc: Adam Buchbinder <adam.buchbinder@gmail.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: stable <stable@vger.kernel.org> # v4.0+ Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13144/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Paul Burton [Thu, 21 Apr 2016 11:25:38 +0000 (12:25 +0100)]
MIPS: Allow emulation for unaligned [LS]DXC1 instructions
If an address error exception occurs for a LDXC1 or SDXC1 instruction,
within the cop1x opcode space, allow it to be passed through to the FPU
emulator rather than resulting in a SIGILL. This causes LDXC1 & SDXC1 to
be handled in a manner consistent with the more common LDC1 & SDC1
instructions.
MIPS: ptrace: Prevent writes to read-only FCSR bits
Correct the cases missed with commit 9b26616c8d9d ("MIPS: Respect the
ISA level in FCSR handling") and prevent writes to read-only FCSR bits
there.
This in particular applies to FP context initialisation where any IEEE
754-2008 bits preset by `mips_set_personality_nan' are cleared before
the relevant ptrace(2) call takes effect and the PTRACE_POKEUSR request
addressing FPC_CSR where no masking of read-only FCSR bits is done.
Remove the FCSR clearing from FP context initialisation then and unify
PTRACE_POKEUSR/FPC_CSR and PTRACE_SETFPREGS handling, by factoring out
code from `ptrace_setfpregs' and calling it from both places.
This mostly matters to soft float configurations where the emulator can
be switched this way to a mode which should not be accessible and cannot
be set with the CTC1 instruction. With hard float configurations any
effect is transient anyway as read-only bits will retain their values at
the time the FP context is restored.
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: stable@vger.kernel.org # v4.0+ Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13239/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Fix a floating-point context restoration regression introduced with
commit 9b26616c8d9d ("MIPS: Respect the ISA level in FCSR handling")
that causes a Floating Point exception and consequently a kernel oops
with hard float configurations when one or more FCSR Enable and their
corresponding Cause bits are set both at a time via a ptrace(2) call.
To do so reinstate Cause bit masking originally introduced with commit b1442d39fac2 ("MIPS: Prevent user from setting FCSR cause bits") to
address this exact problem and then inadvertently removed from the
PTRACE_SETFPREGS request with the commit referred above.
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: stable@vger.kernel.org # v4.0+ Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13238/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Remove a duplicate o32 `elf_check_arch' implementation, move all macro
variants to <asm/elf.h> and define them unconditionally under indvidual
names, substituting alias `elf_check_arch' definitions in variant code.
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13245/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
James Hogan [Wed, 11 May 2016 14:50:32 +0000 (15:50 +0100)]
MIPS: Print GuestCtl1 on machine check exception
The GuestCtl1 CP0 register can contain the GuestID used for root TLB
operations, which affects TLB matching. The other TLB registers are
already dumped out to the log on a machine check exception due to
multiple matching TLB entries, so also dump the value of the GuestCtl1
register if GuestIDs are supported.
James Hogan [Wed, 11 May 2016 14:50:30 +0000 (15:50 +0100)]
MIPS: Add probing & defs for VZ & guest features
Add a few new cpu-features.h definitions for VZ sub-features, namely the
existence of the CP0_GuestCtl0Ext, CP0_GuestCtl1, and CP0_GuestCtl2
registers, and support for GuestID to dialias TLB entries belonging to
different guests.
Also add certain features present in the guest, with the naming scheme
cpu_guest_has_*. These are added separately to the main options bitfield
since they generally parallel similar features in the root context. A
few of these (FPU, MSA, watchpoints, perf counters, CP0_[X]ContextConfig
registers, MAAR registers, and probably others in future) can be
dynamically configured in the guest context, for which the
cpu_guest_has_dyn_* macros are added.
James Hogan [Wed, 11 May 2016 14:50:28 +0000 (15:50 +0100)]
MIPS: Add register definitions for VZ ASE registers
Add various register definitions to <asm/mipsregs.h> for the coprocessor
zero registers in the VZ ASE, namely CP0_GuestCtl0, CP0_GuestCtl0Ext,
CP0_GuestCtl1, CP0_GuestCtl2, CP0_GuestCtl3, and CP0_GTOffset.
Signed-off-by: James Hogan <james.hogan@imgtec.com> Acked-by: David Daney <david.daney@cavium.com> Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13228/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
James Hogan [Wed, 11 May 2016 14:50:27 +0000 (15:50 +0100)]
MIPS: Avoid magic numbers probing kscratch_mask
The decode_config4() function reads kscratch_mask from
CP0_Config4.KScrExist using a hard coded shift and mask. We already have
a definition for the mask in mipsregs.h, so add a definition for the
shift and make use of them.
James Hogan [Wed, 11 May 2016 12:50:53 +0000 (13:50 +0100)]
MIPS: Add perf counter feature
Add CPU feature for standard MIPS r2 performance counters, as determined
by the Config1.PC bit. Both perf_events and oprofile probe this bit, so
lets combine the probing and change both to use cpu_has_perf.
This will also be used for VZ support in KVM to know whether performance
counters exist which can be exposed to guests.
[ralf@linux-mips.org: resolve conflict.]
Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Robert Richter <rric@kernel.org> Cc: linux-mips@linux-mips.org Cc: oprofile-list@lists.sf.net
Patchwork: https://patchwork.linux-mips.org/patch/13226/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
James Hogan [Wed, 11 May 2016 12:50:52 +0000 (13:50 +0100)]
MIPS: Add defs & probing of [X]ContextConfig
The CP0_[X]ContextConfig registers are present if CP0_Config3.CTXTC or
CP0_Config3.SM are set, and provide more control over which bits of
CP0_[X]Context are set to the faulting virtual address on a TLB
exception.
KVM/VZ will need to be able to save and restore these registers in the
guest context, so add the relevant definitions and probing of the
ContextConfig feature in the root context first.
James Hogan [Wed, 11 May 2016 12:50:51 +0000 (13:50 +0100)]
MIPS: Add defs & probing of BadInstr[P] registers
The optional CP0_BadInstr and CP0_BadInstrP registers are written with
the encoding of the instruction that caused a synchronous exception to
occur, and the prior branch instruction if in a delay slot.
These will be useful for instruction emulation in KVM, and especially
for VZ support where reading guest virtual memory is a bit more awkward.
Add CPU option numbers and cpu_has_* definitions to indicate the
presence of each registers, and add code to probe for them using bits in
the CP0_Config3 register.
James Hogan [Wed, 11 May 2016 12:50:50 +0000 (13:50 +0100)]
MIPS: Add defs & probing of extended CP0_EBase
The CP0_EBase register may optionally have a write gate (WG) bit to
allow the upper bits to be written, i.e. bits 31:30 on MIPS32 since r3
(to allow for an exception base outside of KSeg0/KSeg1 when segmentation
control is in use) and bits 63:30 on MIPS64 (which also implies the
extension of CP0_EBase to 64 bits long).
The presence of this feature will need to be known about for VZ support
in order to correctly save and restore all the bits of the guest
CP0_EBase register, so add CPU feature definition and probing for this
feature.
Probing the WG bit on MIPS64 can be a bit fiddly, since 64-bit COP0
register access instructions were UNDEFINED for 32-bit registers prior
to MIPS r6, and it'd be nice to be able to probe without clobbering the
existing state, so there are 3 potential paths:
- If we do a 32-bit read of CP0_EBase and the WG bit is already set, the
register must be 64-bit.
- On MIPS r6 we can do a 64-bit read-modify-write to set CP0_EBase.WG,
since the upper bits will read 0 and be ignored on write if the
register is 32-bit.
- On pre-r6 cores, we do a 32-bit read-modify-write of CP0_EBase. This
avoids the potentially UNDEFINED behaviour, but will clobber the upper
32-bits of CP0_EBase if it isn't a simple sign extension (which also
requires us to ensure BEV=1 or modifying the exception base would be
UNDEFINED too). It is hopefully unlikely a bootloader would set up
CP0_EBase to a 64-bit segment and leave WG=0.
[ralf@linux-mips.org: Resolved merge conflict.]
Signed-off-by: James Hogan <james.hogan@imgtec.com> Tested-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13223/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Aurelien Jarno [Tue, 10 May 2016 22:50:03 +0000 (00:50 +0200)]
MIPS: Octeon: detect and fix byte swapped initramfs
Octeon machines support running in little endian mode. U-Boot usually
runs in big endian-mode. Therefore the initramfs is loaded in big endian
mode, and the kernel later tries to access it in little endian mode.
This patch fixes that by detecting byte swapped initramfs using either the
CPIO header or the header from standard compression methods, and
byte swaps it if needed. It first checks that the header doesn't match
in the native endianness to avoid false detections. It uses the kernel
decompress library so that we don't have to maintain the list of magics
if some decompression methods are added to the kernel.
Make BMIPS4380 and BMIPS5000 advertise support for RIXI through
cpu_probe_broadcom(). bmips_cpu_setup() needs to be called shortly after that,
during prom_init() in order to enable the proper Broadcom-specific register to
turn on RIXI and the "rotr" instruction.
MIPS: Move RIXI exception enabling after vendor-specific cpu_probe
Some processors may not have the RIXI bit advertised in the Config3 register,
not being a MIPS32R2 or R6 core, yet, they might be supporting it through a
different way, which is overriden during vendor-specific cpu_probe().
Move the RIXI exceptions enabling after the vendor-specific cpu_probe()
function has had a change to run and override the current CPU's options with
MIPS_CPU_RIXI.
Some processors, like Broadcom's BMIPS4380 and BMIPS5000 support RIXI and the
"rotr" instruction, which can be used to get a slightly more efficient page
table layout.
Introduce a CONFIG_CPU_HAS_RIXI such that those cores can benefit from this
feature. Perform the conditional check updates where relevant.
Paul Burton [Tue, 19 Apr 2016 08:25:11 +0000 (09:25 +0100)]
MIPS: mm: Panic if an XPA kernel is run without RIXI
XPA kernels hardcode for the presence of RIXI - the PTE format & its
handling presume RI & XI bits. Make this dependence explicit by panicing
if we run on a system that violates it.
Signed-off-by: Paul Burton <paul.burton@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: 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/13125/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
James Hogan [Tue, 19 Apr 2016 08:25:10 +0000 (09:25 +0100)]
MIPS: mm: Don't do MTHC0 if XPA not present
Performing an MTHC0 instruction without XPA being present will trigger a
reserved instruction exception, therefore conditionalise the use of this
instruction when building TLB handlers (build_update_entries()), and in
__update_tlb().
This allows an XPA kernel to run on non XPA hardware without that
instruction implemented, just like it can run on XPA capable hardware
without XPA in use (with the noxpa kernel argument) or with XPA not
configured in hardware.
[paul.burton@imgtec.com:
- Rebase atop other TLB work.
- Add "mm" to subject.
- Handle the __kmap_pgprot case.]
Fixes: c5b367835cfc ("MIPS: Add support for XPA.") Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: David Hildenbrand <dahi@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13124/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Paul Burton [Tue, 19 Apr 2016 08:25:09 +0000 (09:25 +0100)]
MIPS: mm: Simplify build_update_entries
We can simplify build_update_entries by unifying the code for the 36 bit
physical addressing with MIPS32 case with the general case, by using
pte_off_ variables in all cases & handling the trivial
_PAGE_GLOBAL_SHIFT == 0 case in build_convert_pte_to_entrylo. This
leaves XPA as the only special case.
Signed-off-by: Paul Burton <paul.burton@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: 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/13123/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Paul Burton [Tue, 19 Apr 2016 08:25:08 +0000 (09:25 +0100)]
MIPS: mm: Be more explicit about PTE mode bit handling
The XPA case in iPTE_SW or's in software mode bits to the pte_low value
(which is what actually ends up in the high 32 bits of EntryLo...). It
does this presuming that only bits in the upper 16 bits of the 32 bit
pte_low value will be set. Make this assumption explicit with a BUG_ON.
A similar assumption is made for the hardware mode bits, which are or'd
in with a single ori instruction. Make that assumption explicit with a
BUG_ON too.
Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: 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/13122/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Paul Burton [Tue, 19 Apr 2016 08:25:07 +0000 (09:25 +0100)]
MIPS: mm: Pass scratch register through to iPTE_SW
Rather than hardcode a scratch register for the XPA case in iPTE_SW,
pass one through from the work registers allocated by the caller. This
allows for the XPA path to function correctly regardless of the work
registers in use.
Without doing this there are cases (where KScratch registers are
unavailable) in which iPTE_SW will incorrectly clobber $1 despite it
already being in use for the PTE or PTE pointer.
Signed-off-by: Paul Burton <paul.burton@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: 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/13121/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
James Hogan [Tue, 19 Apr 2016 08:25:06 +0000 (09:25 +0100)]
MIPS: mm: Don't clobber $1 on XPA TLB refill
For XPA kernels build_update_entries() uses $1 (at) as a scratch
register, but doesn't arrange for it to be preserved, so it will always
be clobbered by the TLB refill exception. Although this register
normally has a very short lifetime that doesn't cross memory accesses,
TLB refills due to instruction fetches (either on a page boundary or
after preemption) could clobber live data, and its easy to reproduce
the clobber with a little bit of assembler code.
Note that the use of a hardware page table walker will partly mask the
problem, as the TLB refill handler will not always be invoked.
This is fixed by avoiding the use of the extra scratch register. The
pte_high parts (going into the lower half of the EntryLo registers) are
loaded and manipulated separately so as to keep the PTE pointer around
for the other halves (instead of storing in the scratch register), and
the pte_low parts (going into the high half of the EntryLo registers)
are masked with 0x00ffffff using an ext instruction (instead of loading
0x00ffffff into the scratch register and AND'ing).
[paul.burton@imgtec.com:
- Rebase atop other TLB work.
- Use ext instead of an sll, srl sequence.
- Use cpu_has_xpa instead of #ifdefs.
- Modify commit subject to include "mm".]
Fixes: c5b367835cfc ("MIPS: Add support for XPA.") Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13120/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
There are 2 distinct cases in which a kernel for a MIPS32 CPU
(CONFIG_CPU_MIPS32=y) may use 64 bit physical addresses
(CONFIG_PHYS_ADDR_T_64BIT=y):
- 36 bit physical addressing as used by RMI Alchemy & Netlogic XLP/XLR
CPUs.
- MIPS32r5 eXtended Physical Addressing (XPA).
These 2 cases are distinct in that they require different behaviour from
the kernel - the EntryLo registers have different formats. Until Linux
v4.1 we only supported the first case, with code conditional upon the 2
aforementioned Kconfig variables being set. Commit c5b367835cfc ("MIPS:
Add support for XPA.") added support for the second case, but did so by
modifying the code that existed for the first case rather than treating
the 2 cases as distinct. Since the EntryLo registers have different
formats this breaks the 36 bit Alchemy/XLP/XLR case. Fix this by
splitting the 2 cases, with XPA cases now being conditional upon
CONFIG_XPA and the non-XPA case matching the code as it existed prior to
commit c5b367835cfc ("MIPS: Add support for XPA.").
Signed-off-by: Paul Burton <paul.burton@imgtec.com> Reported-by: Manuel Lauss <manuel.lauss@gmail.com> Tested-by: Manuel Lauss <manuel.lauss@gmail.com> Fixes: c5b367835cfc ("MIPS: Add support for XPA.") Cc: James Hogan <james.hogan@imgtec.com> Cc: David Daney <david.daney@cavium.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: Maciej W. Rozycki <macro@linux-mips.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: David Hildenbrand <dahi@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Alex Smith <alex.smith@imgtec.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: stable@vger.kernel.org # v4.1+ Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13119/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Paul Burton [Tue, 19 Apr 2016 08:25:04 +0000 (09:25 +0100)]
MIPS: mm: Unify pte_page definition
The same definition for pte_page is duplicated for the MIPS32
PHYS_ADDR_T_64BIT case & the generic case. Unify them by moving a single
definition outside of preprocessor conditionals.
Signed-off-by: Paul Burton <paul.burton@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: 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/13117/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Paul Burton [Tue, 19 Apr 2016 08:25:03 +0000 (09:25 +0100)]
MIPS: mm: Standardise on _PAGE_NO_READ, drop _PAGE_READ
Ever since support for RI/XI was implemented by commit 6dd9344cfc41
("MIPS: Implement Read Inhibit/eXecute Inhibit") we've had a mixture of
_PAGE_READ & _PAGE_NO_READ bits. Rather than keep both around, switch
away from using _PAGE_READ to determine page presence & instead invert
the use to _PAGE_NO_READ. Wherever we formerly had no definition for
_PAGE_NO_READ, change what was _PAGE_READ to _PAGE_NO_READ. The end
result is that we consistently use _PAGE_NO_READ to determine whether a
page is readable, regardless of whether RI/XI is implemented.
Signed-off-by: Paul Burton <paul.burton@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: David Daney <david.daney@cavium.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: Maciej W. Rozycki <macro@linux-mips.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Alex Smith <alex.smith@imgtec.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13116/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Paul Burton [Tue, 19 Apr 2016 08:25:02 +0000 (09:25 +0100)]
MIPS: Use enums to make asm/pgtable-bits.h readable
asm/pgtable-bits.h has grown to become an unreadable mess of #ifdef
directives defining bits conditionally upon other bits all at the
preprocessing stage, for no good reason.
Instead of having quite so many #ifdef's, simply use enums to provide
sequential numbering for bit shifts, without having to keep track
manually of what the last bit defined was. Masks are defined separately,
after the shifts, which allows for most of their definitions to be
reused for all systems rather than duplicated.
This patch is not intended to make any behavioural change to the code -
all bits should be used in the same way they were before this patch.
Signed-off-by: Paul Burton <paul.burton@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: Maciej W. Rozycki <macro@linux-mips.org> Cc: Alex Smith <alex.smith@imgtec.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13115/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
asm/pgtable-bits.h is included in 2 assembly files and thus has to
ifdef around C code, however nothing defined by the header is used
in either of the assembly files that include it.
Remove the redundant inclusions such that asm/pgtable-bits.h doesn't
need to #ifdef around C code, for cleanliness and in preparation for
later patches which will add more C.
Signed-off-by: Paul Burton <paul.burton@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: Maciej W. Rozycki <macro@linux-mips.org> Cc: Jonas Gorski <jogo@openwrt.org> Cc: Alex Smith <alex.smith@imgtec.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13114/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
James Hogan [Tue, 19 Apr 2016 08:25:00 +0000 (09:25 +0100)]
MIPS: Fix HTW config on XPA kernel without LPA enabled
The hardware page table walker (HTW) configuration is broken on XPA
kernels where XPA couldn't be enabled (either nohtw or the hardware
doesn't support it). This is because the PWSize.PTEW field (PTE width)
was only set to 8 bytes (an extra shift of 1) in config_htw_params() if
PageGrain.ELPA (enable large physical addressing) is set. On an XPA
kernel though the size of PTEs is fixed at 8 bytes regardless of whether
XPA could actually be enabled.
Fix the initialisation of this field based on sizeof(pte_t) instead.
Fixes: c5b367835cfc ("MIPS: Add support for XPA.") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Steven J. Hill <sjhill@realitydiluted.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: 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/13113/ Signed-off-by: Paul Burton <paul.burton@imgtec.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
James Hogan [Tue, 19 Apr 2016 08:24:59 +0000 (09:24 +0100)]
MIPS: Separate XPA CPU feature into LPA and MVH
XPA (eXtended Physical Addressing) should be detected as a combination
of two architectural features:
- Large Physical Address (as per Config3.LPA). With XPA this will be set
on MIPS32r5 cores, but it may also be set for MIPS64r2 cores too.
- MTHC0/MFHC0 instructions (as per Config5.MVH). With XPA this will be
set, but it may also be set in VZ guest context even when Config3.LPA
in the guest context has been cleared by the hypervisor.
As such, XPA is only usable if both bits are set. Update CPU features to
separate these two features, with cpu_has_xpa requiring both to be set.
Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Maciej W. Rozycki <macro@imgtec.com> Cc: Joshua Kinard <kumba@gentoo.org> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13112/ Signed-off-by: Paul Burton <paul.burton@imgtec.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Paul Burton [Thu, 21 Apr 2016 13:04:55 +0000 (14:04 +0100)]
MIPS: math-emu: Fix jalr emulation when rd == $0
When emulating a jalr instruction with rd == $0, the code in
isBranchInstr was incorrectly writing to GPR $0 which should actually
always remain zeroed. This would lead to any further instructions
emulated which use $0 operating on a bogus value until the task is next
context switched, at which point the value of $0 in the task context
would be restored to the correct zero by a store in SAVE_SOME. Fix this
by not writing to rd if it is $0.
Fixes: 102cedc32a6e ("MIPS: microMIPS: Floating point support.") Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Maciej W. Rozycki <macro@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: stable <stable@vger.kernel.org> # v3.10
Patchwork: https://patchwork.linux-mips.org/patch/13160/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Paul Burton [Thu, 21 Apr 2016 13:04:54 +0000 (14:04 +0100)]
MIPS: math-emu: Fix m{add,sub}.s shifts
The code in _sp_maddf (formerly ieee754sp_madd) appears to have been
copied verbatim from ieee754sp_add, and although it's adding the
unpacked "r" & "z" floats it kept using macros that operate on "x" &
"y". This led to the addition being carried out incorrectly on some
mismash of the product, accumulator & multiplicand fields. Typically
this would lead to the assertions "ze == re" & "ze <= SP_EMAX" failing
since ze & re hadn't been operated upon.
Signed-off-by: Paul Burton <paul.burton@imgtec.com> Fixes: e24c3bec3e8e ("MIPS: math-emu: Add support for the MIPS R6 MADDF FPU instruction") Cc: Adam Buchbinder <adam.buchbinder@gmail.com> Cc: Maciej W. Rozycki <macro@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13159/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Paul Burton [Thu, 21 Apr 2016 13:04:53 +0000 (14:04 +0100)]
MIPS: math-emu: Fix code indentation
A line incrementing the re variable was indented a level too deep in
ieee754dp_mul, making the code unclear to read. Fix the indentation.
This appears to have been copied verbatim along with the rest of the
multiplication code to ieee754dp_maddf, now _dp_maddf, too so fix the
indentation there too.
Paul Burton [Thu, 21 Apr 2016 13:04:52 +0000 (14:04 +0100)]
MIPS: math-emu: Fix bit-width in ieee754dp_{mul, maddf, msubf} comments
A comment in ieee754dp_mul indicates that the code is about to perform a
32b x 32b multiplication & keep the high 32b of the result. It appears
this was copied from the single-precision multiplication code, since the
code actually goes on to perform a 64b x 64b multiplication & keep the
high 64b of the result. Fix the comment to indicate 64b.
It appears also that this comment was copied verbatim along with the
rest of the multiplication code into ieee754dp_maddf, which has since
been renamed _dp_maddf. Fix the same issue there.
Paul Burton [Thu, 21 Apr 2016 13:04:51 +0000 (14:04 +0100)]
MIPS: math-emu: Add z argument macros
Introduce macros for handling the "z" argument to maddf & msubf, making
its handling consistent with that of the "x" & "y" arguments rather than
open-coding equivalents.
Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Maciej W. Rozycki <macro@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13156/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Paul Burton [Thu, 21 Apr 2016 13:04:50 +0000 (14:04 +0100)]
MIPS: math-emu: Unify ieee754dp_m{add,sub}f
The code for emulating MIPSr6 madd.d & msub.d instructions has
previously been implemented as 2 different functions, namely
ieee754dp_maddf & ieee754dp_msubf. The difference in behaviour of these
2 instructions is merely the sign of the product, so we can easily share
the code implementing them. Do this for the double precision variant,
removing the original ieee754dp_msubf in favor of reusing the code from
ieee754dp_maddf.
Paul Burton [Thu, 21 Apr 2016 13:04:49 +0000 (14:04 +0100)]
MIPS: math-emu: Unify ieee754sp_m{add,sub}f
The code for emulating MIPSr6 madd.s & msub.s instructions has
previously been implemented as 2 different functions, namely
ieee754sp_maddf & ieee754sp_msubf. The difference in behaviour of these
2 instructions is merely the sign of the product, so we can easily share
the code implementing them. Do this for the single precision variant,
removing the original ieee754sp_msubf in favor of reusing the code from
ieee754sp_maddf.
Add support for emulating the MIPSr6 sel.fmt instruction, which was
previously missing from the FPU emulation code. This instruction selects
its result from 2 possible source registers, based upon bit 0 of the
destination register, and is valid only for S (single) & D (double) data
types.
Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Maciej W. Rozycki <macro@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13153/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Paul Burton [Thu, 21 Apr 2016 13:04:46 +0000 (14:04 +0100)]
MIPS: Fix BC1{EQ,NE}Z return offset calculation
The conditions for branching when emulating the BC1EQZ & BC1NEZ
instructions were backwards, leading to each of those instructions being
treated as the other. Fix this by reversing the conditions, and clear up
the code a little for readability & checkpatch.
Fixes: c8a34581ec09 ("MIPS: Emulate the BC1{EQ,NE}Z FPU instructions") Signed-off-by: Paul Burton <paul.burton@imgtec.com> Reviewed-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/13151/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Paul Burton [Thu, 21 Apr 2016 13:04:45 +0000 (14:04 +0100)]
MIPS: math-emu: Fix BC1{EQ,NE}Z emulation
The conditions for branching when emulating the BC1EQZ & BC1NEZ
instructions were backwards, leading to each of those instructions being
treated as the other. Fix this by reversing the conditions, and clear up
the code a little for readability & checkpatch.
Fixes: c909ca718e8f ("MIPS: math-emu: Emulate missing BC1{EQ,NE}Z instructions") Signed-off-by: Paul Burton <paul.burton@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: Maciej W. Rozycki <macro@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13150/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Rabin Vincent [Thu, 28 Apr 2016 09:03:09 +0000 (11:03 +0200)]
MIPS: Add support for extending builtin cmdline
Allow the builtin command line to be extended by what the bootloader
passes in. For example, the bootloader can pass specific arguments
depending on the boot mode, and these should override the defaults in
the builtin cmdline.
The default MIPS_CMDLINE_FROM_BOOTLOADER option prepends the
bootloader's cmdline to the builtin cmdline so is not suitable for this
purpose.
Paul Burton [Fri, 6 May 2016 13:36:24 +0000 (14:36 +0100)]
MIPS: Support extended ASIDs
Add support for extended ASIDs as determined by the Config4.AE bit.
Since the only supported CPUs known to implement this are Netlogic XLP
and MIPS I6400, select this variable ASID support based upon
CONFIG_CPU_XLP and CONFIG_CPU_MIPSR6.
Signed-off-by: Paul Burton <paul.burton@imgtec.com> Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Jayachandran C. <jchandra@broadcom.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/13211/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Paul Burton [Fri, 6 May 2016 13:36:23 +0000 (14:36 +0100)]
MIPS: Retrieve ASID masks using function accepting struct cpuinfo_mips
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>
James Hogan [Fri, 6 May 2016 13:36:22 +0000 (14:36 +0100)]
MIPS: KVM/locore.S: Relax noat
Now that the at register ($1) is no longer saved by
__kvm_mips_vcpu_run(), relax the noat assembler directive so that it
only applies around code where at is restored before entering guest, and
saved after exiting guest.
Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13209/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
James Hogan [Fri, 6 May 2016 13:36:21 +0000 (14:36 +0100)]
MIPS: KVM/locore.S: Only preserve callee saved registers
Update __kvm_mips_vcpu_run() to only save and restore callee saved
registers. It is always called using the standard ABIs, so the caller
will preserve any other registers that need preserving.
Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13208/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Paul Burton [Fri, 6 May 2016 13:36:20 +0000 (14:36 +0100)]
MIPS: KVM: Abstract guest ASID mask
In preparation for supporting varied widths of ASID mask in the kernel
in general, switch KVM's guest ASIDs to a new KVM_ENTRYHI_ASID
definition based on the 8-bit MIPS_ENTRYHI_ASID instead of ASID_MASK.
It could potentially be used to support extended guest ASIDs in the
future.
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/13207/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
James Hogan [Fri, 6 May 2016 13:36:18 +0000 (14:36 +0100)]
MIPS: KVM/locore.S: Don't preserve host ASID around vcpu_run
MIPS KVM uses different ASIDs for guest execution than for the host.
The host ASID is saved on the stack when entering the guest with
__kvm_mips_vcpu_run(), and restored again before returning back to the
caller (exit to userland).
- This does not take into account that pre-emption may have taken place
during that time, which may have started a new ASID cycle and resulted
in that process' ASID being invalidated and reused.
- This does not take into account that the process may have migrated to
a different CPU during that time, with a different ASID assignment
since they are managed per-CPU.
- It is actually redundant, since the host ASID will be restored
correctly by kvm_arch_vcpu_put(), which is called almost immediately
after kvm_arch_vcpu_ioctl_run() returns.
Therefore drop this code from locore.S
Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13206/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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