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8 years agodt/bindings: Correct clk binding example for PIC32 pinctrl
Purna Chandra Mandal [Tue, 17 May 2016 05:05:56 +0000 (10:35 +0530)]
dt/bindings: Correct clk binding example for PIC32 pinctrl

Update binding example based on new clock binding scheme.
[1] Documentation/devicetree/bindings/clock/microchip,pic32.txt

Signed-off-by: Purna Chandra Mandal <purna.mandal@microchip.com>
Acked-by: Rob Herring <robh@kernel.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Kumar Gala <galak@codeaurora.org>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Joshua Henderson <digitalpeer@digitalpeer.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13266/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agodt/bindings: Correct clk binding example for PIC32 SDHCI
Purna Chandra Mandal [Tue, 17 May 2016 05:05:55 +0000 (10:35 +0530)]
dt/bindings: Correct clk binding example for PIC32 SDHCI

Update binding example based on new clock binding documentation.
[1] Documentation/devicetree/bindings/clock/microchip,pic32.txt

Signed-off-by: Purna Chandra Mandal <purna.mandal@microchip.com>
Acked-by: Rob Herring <robh@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Kumar Gala <galak@codeaurora.org>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Joshua Henderson <digitalpeer@digitalpeer.com>
Cc: Andrei Pistirica <andrei.pistirica@microchip.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13265/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: Fix incomplete separation of XPA CPU feature
James Hogan [Tue, 17 May 2016 23:08:49 +0000 (00:08 +0100)]
MIPS: Fix incomplete separation of XPA CPU feature

Commit 67b34e674e93 ("MIPS: Separate XPA CPU feature into LPA and MVH")
wasn't fully applied, possibly due to a conflict with commit
18266baff9b6 ("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: 67b34e674e93 ("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>
8 years agoirqchip: mips-gic: Setup EIC mode on each CPU if it's in use
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>
8 years agoMIPS: smp-cps: Clear Status IPL field when using EIC
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>
8 years agoMIPS: Clear Status IPL field when using EIC
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>
8 years agoMIPS: pic32mzda: fix getting timer clock rate.
Purna Chandra Mandal [Tue, 17 May 2016 05:05:52 +0000 (10:35 +0530)]
MIPS: pic32mzda: fix getting timer clock rate.

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.

Signed-off-by: Purna Chandra Mandal <purna.mandal@microchip.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: Joshua Henderson <digitalpeer@digitalpeer.com>
Patchwork: https://patchwork.linux-mips.org/patch/13262/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: ath79: fix regression in PCI window initialization
Felix Fietkau [Mon, 16 May 2016 17:51:55 +0000 (19:51 +0200)]
MIPS: ath79: fix regression in PCI window initialization

ath79_ddr_pci_win_base has the type void __iomem *, so register offsets
need to be a multiple of 4.

Cc: Alban Bedel <albeu@free.fr>
Fixes: 5b8f78e91a3d ("MIPS: ath79: Improve the DDR controller interface")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Cc: sergei.shtylyov@cogentembedded.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13258/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: ath79: make ath79_ddr_ctrl_init() compatible for newer SoCs
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

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Cc: albeu@free.fr
Cc: sergei.shtylyov@cogentembedded.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13257/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: Fix VZ probe gas errors with binutils <2.24
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.

Fixes: 56e8cb7dd937 ("MIPS: Add guest CP0 accessors")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-next@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13255/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: perf: Fix I6400 event numbers
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: 267fb17fc57a ("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>
8 years agoMIPS: DEC: Export `ioasic_ssr_lock' to modules
Maciej W. Rozycki [Mon, 16 May 2016 12:15:47 +0000 (13:15 +0100)]
MIPS: DEC: Export `ioasic_ssr_lock' to modules

Fix a modular `declance' regression caused by LMO commit bb46bf30d13f
("DECstation SCSI driver clean-ups.")

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13256/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: MSA: Fix a link error on `_init_msa_upper' with older GCC
Maciej W. Rozycki [Tue, 17 May 2016 05:12:27 +0000 (06:12 +0100)]
MIPS: MSA: Fix a link error on `_init_msa_upper' with older GCC

Fix a build regression from commit 8ebd5b8ceae4 ("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>
8 years agoMIPS: CM: Fix compilation error when !MIPS_CM
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 91d0e033f399 (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>
8 years agoMIPS: Fix genvdso error on rebuild
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

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13250/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoUSB: ohci-jz4740: Remove obsolete driver
Maarten ter Huurne [Mon, 18 Apr 2016 18:58:53 +0000 (20:58 +0200)]
USB: ohci-jz4740: Remove obsolete driver

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.

Signed-off-by: Maarten ter Huurne <maarten@treewalker.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13105/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: JZ4740: Probe OHCI platform device via DT
Maarten ter Huurne [Mon, 18 Apr 2016 18:58:52 +0000 (20:58 +0200)]
MIPS: JZ4740: Probe OHCI platform device via DT

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.

Signed-off-by: Maarten ter Huurne <maarten@treewalker.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13104/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: JZ4740: Qi LB60: Remove support for AVT2 variant
Maarten ter Huurne [Mon, 18 Apr 2016 18:58:51 +0000 (20:58 +0200)]
MIPS: JZ4740: Qi LB60: Remove support for AVT2 variant

AVT2 was a prototype board of which about 5 were made, none of which
are in use anymore.

Signed-off-by: Maarten ter Huurne <maarten@treewalker.org>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13103/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: pistachio: Determine SoC revision during boot
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>
8 years agoMIPS: BMIPS: Adjust mips-hpt-frequency for BCM7435
Florian Fainelli [Tue, 19 Apr 2016 22:35:39 +0000 (15:35 -0700)]
MIPS: BMIPS: Adjust mips-hpt-frequency for BCM7435

The CPU actually runs at 1405Mhz which gives us a 175625000 Hz MIPS timer
frequency (CPU frequency / 8).

Fixes: b00d3ed62790 ("MIPS: BMIPS: Add BCM7435 dtsi")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: john@phrozen.org
Cc: cernekee@gmail.com
Cc: jaedon.shin@gmail.com
Patchwork: https://patchwork.linux-mips.org/patch/13132/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agomips: mt7620: fallback to SDRAM when syscfg0 does not have a valid value for the...
Sashka Nochkin [Wed, 20 Apr 2016 03:44:45 +0000 (23:44 -0400)]
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.

Signed-off-by: Sashka Nochkin <linux-mips@durdom.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13135/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: Prevent "restoration" of MSA context in non-MSA kernels
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: 61a4dba00ec6 ("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>
8 years agoMIPS: cevt-r4k: Dynamically calculate min_delta_ns
James Hogan [Fri, 22 Apr 2016 17:19:17 +0000 (18:19 +0100)]
MIPS: cevt-r4k: Dynamically calculate min_delta_ns

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>
8 years agoMIPS: malta-time: Take seconds into account
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>
8 years agoMIPS: malta-time: Start GIC count before syncing to RTC
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>
8 years agoMIPS: Force CPUs to lose FP context during mode switches
Paul Burton [Thu, 21 Apr 2016 11:43:58 +0000 (12:43 +0100)]
MIPS: Force CPUs to lose FP context during mode switches

Commit bc287954f45f ("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: bc287954f45f ("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>
8 years agoMIPS: Disable preemption during prctl(PR_SET_FP_MODE, ...)
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: bc287954f45f ("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>
8 years agoMIPS: Allow emulation for unaligned [LS]DXC1 instructions
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.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Tested-by: Aurelien Jarno <aurelien@aurel32.net>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13143/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: ptrace: Prevent writes to read-only FCSR bits
Maciej W. Rozycki [Thu, 12 May 2016 09:19:08 +0000 (10:19 +0100)]
MIPS: ptrace: Prevent writes to read-only FCSR bits

Correct the cases missed with commit 36341133ce56 ("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>
8 years agoMIPS: ptrace: Fix FP context restoration FCSR regression
Maciej W. Rozycki [Thu, 12 May 2016 09:18:27 +0000 (10:18 +0100)]
MIPS: ptrace: Fix FP context restoration FCSR regression

Fix a floating-point context restoration regression introduced with
commit 36341133ce56 ("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
0d15293986be ("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>
8 years agoMIPS: dts: pic32: Update dts to reflect new PIC32MZDA clk binding
Purna Chandra Mandal [Fri, 13 May 2016 07:52:41 +0000 (13:22 +0530)]
MIPS: dts: pic32: Update dts to reflect new PIC32MZDA clk binding

- now clock nodes definition is merged with core .dtsi file
- only one rootclk is now part of DT
- clock clients also updated based on new binding doc

Signed-off-by: Purna Chandra Mandal <purna.mandal@microchip.com>
Signed-off-by: Joshua Henderson <joshua.henderson@microchip.com>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Kumar Gala <galak@codeaurora.org>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Sandeep Sheriker <sandeepsheriker.mallikarjun@microchip.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-clk@vger.kernel.org
Cc: devicetree@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13248/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoCLK: microchip: Add Microchip PIC32 clock driver.
Purna Chandra Mandal [Fri, 13 May 2016 07:52:40 +0000 (13:22 +0530)]
CLK: microchip: Add Microchip PIC32 clock driver.

This clock driver implements PIC32 specific clock-tree. clock-tree
entities can only be configured through device-tree file (OF).

Signed-off-by: Purna Chandra Mandal <purna.mandal@microchip.com>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-clk@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13247/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agodt/bindings/clk: Add PIC32 clock binding documentation.
Purna Chandra Mandal [Fri, 13 May 2016 07:52:39 +0000 (13:22 +0530)]
dt/bindings/clk: Add PIC32 clock binding documentation.

Document the devicetree bindings for the clock driver found on Microchip
PIC32 class devices.

Signed-off-by: Purna Chandra Mandal <purna.mandal@microchip.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Purna Chandra Mandal <purna.mandal@microchip.com>
Cc: Kumar Gala <galak@codeaurora.org>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-clk@vger.kernel.org
Cc: devicetree@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13246/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: ELF: Unify ABI classification macros
Maciej W. Rozycki [Fri, 13 May 2016 06:21:40 +0000 (07:21 +0100)]
MIPS: ELF: Unify ABI classification macros

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>
8 years agoMIPS: ELF: Unify __MIPS_O32_FP64_MUST_BE_ZERO definitions
Maciej W. Rozycki [Fri, 13 May 2016 06:20:55 +0000 (07:20 +0100)]
MIPS: ELF: Unify __MIPS_O32_FP64_MUST_BE_ZERO definitions

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13244/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: ELF: Deconditionalise ABI flags definitions
Maciej W. Rozycki [Fri, 13 May 2016 06:20:16 +0000 (07:20 +0100)]
MIPS: ELF: Deconditionalise ABI flags definitions

Move the `mips_elf_abiflags_v0' structure and FP ABI flag macros outside
#ifndef ELF_ARCH.  These are public interfaces.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13243/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: Print GuestCtl1 on machine check exception
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.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13232/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: dump_tlb: Preserve and dump GuestID
James Hogan [Wed, 11 May 2016 14:50:31 +0000 (15:50 +0100)]
MIPS: dump_tlb: Preserve and dump GuestID

The GuestID for root TLB operations (GuestCtl1.RID) is modified by TLB
reads, so needs preserving by dump_tlb() like the ASID field of EntryHi.

Also dump the GuestID of each entry if it exists alongside the ASID, as
it forms an important part of the TLB entry when VZ guests are used.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13230/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: Add probing & defs for VZ & guest features
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.

[ralf@linux-mips.org: Resolve merge conflict.]

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13231/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: Add guest CP0 accessors
James Hogan [Wed, 11 May 2016 14:50:29 +0000 (15:50 +0100)]
MIPS: Add guest CP0 accessors

Add guest CP0 accessors and guest TLB operations along the same lines as
the existing macros and functions for the root CP0.

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/13229/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: Add register definitions for VZ ASE registers
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>
8 years agoMIPS: Avoid magic numbers probing kscratch_mask
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.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13227/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: Add perf counter feature
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>
8 years agoMIPS: Add defs & probing of [X]ContextConfig
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.

[ralf@linux-mips.org: resolve merge conflict.]

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13225/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: Add defs & probing of BadInstr[P] registers
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.

[ralf@linux-mips.org: resolve merge conflict.]

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13224/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: Add defs & probing of extended CP0_EBase
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>
8 years agoMIPS: Define & use CP0_EBase bit definitions
James Hogan [Wed, 11 May 2016 12:50:49 +0000 (13:50 +0100)]
MIPS: Define & use CP0_EBase bit definitions

Add definitions for the bits & fields in the CP0_EBase register, and use
them from a few different places in arch/mips which hardcoded these
values.

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/13222/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: alchemy: Remove CLK_IS_ROOT
Stephen Boyd [Wed, 20 Apr 2016 01:34:37 +0000 (18:34 -0700)]
MIPS: alchemy: Remove CLK_IS_ROOT

This flag is a no-op now (see commit a2287edcf07f "clk: Deprecate
CLK_IS_ROOT", 2016-02-02) so remove it.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Manuel Lauss <manuel.lauss@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13134/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: ath79: Remove CLK_IS_ROOT
Stephen Boyd [Wed, 20 Apr 2016 01:33:21 +0000 (18:33 -0700)]
MIPS: ath79: Remove CLK_IS_ROOT

This flag is a no-op now (see commit a2287edcf07f "clk: Deprecate
CLK_IS_ROOT", 2016-02-02) so remove it.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Antony Pavlov <antonynpavlov@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13133/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: Octeon: detect and fix byte swapped initramfs
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.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Acked-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13219/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: BMIPS: BMIPS4380 and BMIPS5000 support RIXI
Florian Fainelli [Tue, 9 Feb 2016 20:55:53 +0000 (12:55 -0800)]
MIPS: BMIPS: BMIPS4380 and BMIPS5000 support RIXI

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.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: john@phrozen.org
Cc: cernekee@gmail.com
Cc: jon.fraser@broadcom.com
Cc: pgynther@google.com
Cc: paul.burton@imgtec.com
Cc: ddaney.cavm@gmail.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12507/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: Move RIXI exception enabling after vendor-specific cpu_probe
Florian Fainelli [Tue, 9 Feb 2016 20:55:52 +0000 (12:55 -0800)]
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.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: john@phrozen.org
Cc: cernekee@gmail.com
Cc: jon.fraser@broadcom.com
Cc: pgynther@google.com
Cc: paul.burton@imgtec.com
Cc: ddaney.cavm@gmail.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12506/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: Allow RIXI to be used on non-R2 or R6 cores
Florian Fainelli [Tue, 9 Feb 2016 20:55:51 +0000 (12:55 -0800)]
MIPS: Allow RIXI to be used on non-R2 or R6 cores

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.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: john@phrozen.org
Cc: cernekee@gmail.com
Cc: jon.fraser@broadcom.com
Cc: pgynther@google.com
Cc: paul.burton@imgtec.com
Cc: ddaney.cavm@gmail.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12505/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: mm: Panic if an XPA kernel is run without RIXI
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>
8 years agoMIPS: mm: Don't do MTHC0 if XPA not present
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: 620119a62535 ("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>
8 years agoMIPS: mm: Simplify build_update_entries
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>
8 years agoMIPS: mm: Be more explicit about PTE mode bit handling
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>
8 years agoMIPS: mm: Pass scratch register through to iPTE_SW
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>
8 years agoMIPS: mm: Don't clobber $1 on XPA TLB refill
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: 620119a62535 ("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>
8 years agoMIPS: mm: Fix MIPS32 36b physical addressing (alchemy, netlogic)
Paul Burton [Tue, 19 Apr 2016 08:25:05 +0000 (09:25 +0100)]
MIPS: mm: Fix MIPS32 36b physical addressing (alchemy, netlogic)

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 620119a62535 ("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 620119a62535 ("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: 620119a62535 ("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>
8 years agoMIPS: mm: Unify pte_page definition
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>
8 years agoMIPS: mm: Standardise on _PAGE_NO_READ, drop _PAGE_READ
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 b921f59731ff
("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>
8 years agoMIPS: Use enums to make asm/pgtable-bits.h readable
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>
8 years agoMIPS: Remove redundant asm/pgtable-bits.h inclusions
Paul Burton [Tue, 19 Apr 2016 08:25:01 +0000 (09:25 +0100)]
MIPS: Remove redundant asm/pgtable-bits.h inclusions

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>
8 years agoMIPS: Fix HTW config on XPA kernel without LPA enabled
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: 620119a62535 ("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>
8 years agoMIPS: Separate XPA CPU feature into LPA and MVH
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>
8 years agoMIPS: math-emu: Fix jalr emulation when rd == $0
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: a8dfab5f3f5d ("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>
8 years agoMIPS: math-emu: Fix m{add,sub}.s shifts
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: 439a36e5a818 ("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>
8 years agoMIPS: math-emu: Fix code indentation
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.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13158/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: math-emu: Fix bit-width in ieee754dp_{mul, maddf, msubf} comments
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.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13157/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: math-emu: Add z argument macros
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>
8 years agoMIPS: math-emu: Unify ieee754dp_m{add,sub}f
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.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13155/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: math-emu: Unify ieee754sp_m{add,sub}f
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.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13154/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: math-emu: Emulate MIPSr6 sel.fmt instruction
Paul Burton [Thu, 21 Apr 2016 13:04:48 +0000 (14:04 +0100)]
MIPS: math-emu: Emulate MIPSr6 sel.fmt instruction

Add support for emulating the MIPSr6 sel.fmt instruction, which was
previously missing from the FPU emulation code. This instruction selects
its result from 2 possible source registers, based upon bit 0 of the
destination register, and is valid only for S (single) & D (double) data
types.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13153/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: inst: Declare fsel_op for sel.fmt instruction
Paul Burton [Thu, 21 Apr 2016 13:04:47 +0000 (14:04 +0100)]
MIPS: inst: Declare fsel_op for sel.fmt instruction

Declare the opcode for the MIPSr6 sel.fmt instruction, as fsel_op in
order to match other FP op names.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13152/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: Fix BC1{EQ,NE}Z return offset calculation
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: a6d1a2a66cbe ("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>
8 years agoMIPS: math-emu: Fix BC1{EQ,NE}Z emulation
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: 42701c0f68d5 ("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>
8 years agoMIPS: Add support for extending builtin cmdline
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.

Signed-off-by: Rabin Vincent <rabinv@axis.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13181/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: Don't add leading spacing to command lines
Rabin Vincent [Thu, 28 Apr 2016 09:03:08 +0000 (11:03 +0200)]
MIPS: Don't add leading spacing to command lines

The leading spaces don't affect functionality but are unnecessary.

Signed-off-by: Rabin Vincent <rabinv@axis.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13180/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: genex: Indent delay slots & clean whitespace
James Hogan [Fri, 29 Apr 2016 16:29:29 +0000 (17:29 +0100)]
MIPS: genex: Indent delay slots & clean whitespace

Various branches and jumps in noreorder parts of genex.S don't have
their delay slot instructions indented conventionally with the extra
space.

Fix these, as well as various other inconsistent whitespace problems in
this file, such as spaces used after some opcodes instead of a tab.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13196/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: Support extended ASIDs
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>
8 years agoMIPS: Retrieve ASID masks using function accepting struct cpuinfo_mips
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>
8 years agoMIPS: KVM/locore.S: Relax noat
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>
8 years agoMIPS: KVM/locore.S: Only preserve callee saved registers
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>
8 years agoMIPS: KVM: Abstract guest ASID mask
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>
8 years agoMIPS: Add & use CP0_EntryHi ASID definitions
James Hogan [Fri, 6 May 2016 13:36:19 +0000 (14:36 +0100)]
MIPS: Add & use CP0_EntryHi ASID definitions

Add definitions for the ASID field in CP0_EntryHi (along with the soon
to be used ASIDX field), and use them in a few previously hardcoded
cases.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Manuel Lauss <manuel.lauss@gmail.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/13205/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: KVM/locore.S: Don't preserve host ASID around vcpu_run
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>
8 years agoMIPS: Change my email address
John Crispin [Thu, 5 May 2016 07:57:56 +0000 (09:57 +0200)]
MIPS: Change my email address

The old address is no longer valid. Use the my new one instead.

Signed-off-by: John Crispin <john@phrozen.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13201/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMAINTAINERS: Change my email address
John Crispin [Thu, 5 May 2016 07:57:55 +0000 (09:57 +0200)]
MAINTAINERS: Change my email address

The old address is no longer valid. Use the my new one instead.

Signed-off-by: John Crispin <john@phrozen.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13200/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: Implement __arch_bitrev* using bitswap for MIPSr6
Paul Burton [Fri, 6 May 2016 12:35:03 +0000 (13:35 +0100)]
MIPS: Implement __arch_bitrev* using bitswap for MIPSr6

Release 6 of the MIPS architecture introduced the bitswap instruction,
which reverses the bits within each byte of a word. Make use of this
instruction to implement the __arch_bitrev* functions, which should be
faster for most MIPSr6 CPUs, reduces code size slightly and allows us to
avoid the lookup table used by the generic implementation, saving 256
bytes in the kernel binary by dropping that.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13204/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: Remove no longer needed work_on_cpu() call
Anna-Maria Gleixner [Mon, 2 May 2016 09:00:49 +0000 (11:00 +0200)]
MIPS: Remove no longer needed work_on_cpu() call

Since commit 354a9025185a ("cpu/hotplug: Fix rollback during error-out
in __cpu_disable()") it is ensured that callbacks of CPU_ONLINE and
CPU_DOWN_PREPARE are processed on the hotplugged CPU. Due to this
work_on_cpu() calls are no longer required.

Replace work_on_cpu() with a direct call of mips_cdmm_bus_up() or
mips_cdmm_bus_down(). Description of those functions are adapted.

Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: rt@linutronix.de
Patchwork: https://patchwork.linux-mips.org/patch/13197/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: make PCI_DMA_BUS_IS_PHYS=1 constant
Sergey Ryazanov [Sat, 30 Aug 2014 02:06:28 +0000 (06:06 +0400)]
MIPS: make PCI_DMA_BUS_IS_PHYS=1 constant

No one of supported MIPS machines has an IOMMU unit, so we can safely define
PCI_DMA_BUS_IS_PHYS = 1. Also remove iommu flag from the pci controller
structure, since it is useless.

Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Cc: Linux MIPS <linux-mips@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/7604/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS64: Support of at least 48 bits of SEGBITS
Leonid Yegoshin [Fri, 15 May 2015 01:34:43 +0000 (18:34 -0700)]
MIPS64: Support of at least 48 bits of SEGBITS

SEGBITS is 40 bits or more, depending on CPU type.  Introduces optional
support for 48 bits of application virtual address space.  Only 16K and
64K pages are supported.

Enabling will result in a memory overhead of a small number of pages for
small applications.  For 64K pages a 3rd level of page tables is required
which has some impact during software TLB refill.

[ralf@linux-mips.org: Fixed things raised in the review of the version
posted and changed kconfig to be a bit more userfriendly.]

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: aleksey.makarov@auriga.com
Cc: james.hogan@imgtec.com
Cc: paul.burton@imgtec.com
Cc: david.daney@cavium.com
Cc: peterz@infradead.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: davidlohr@hp.com
Cc: kirill@shutemov.name
Cc: akpm@linux-foundation.org
Cc: mingo@kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/10051/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS64: signal: Fix o32 sigaction syscall
Leonid Yegoshin [Mon, 19 Oct 2015 18:39:55 +0000 (11:39 -0700)]
MIPS64: signal: Fix o32 sigaction syscall

MIPS32 o32 ABI sigaction() processing on MIPS64 n64 kernel was incorrectly
set to processing aka rt_sigaction() variant only.

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: paul.burton@imgtec.com
Cc: richard@nod.at
Cc: luto@amacapital.net
Cc: alex.smith@imgtec.com
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: mpe@ellerman.id.au
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11321/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: remove aliasing alignment if HW has antialising support
Leonid Yegoshin [Fri, 20 Nov 2015 01:38:21 +0000 (17:38 -0800)]
MIPS: remove aliasing alignment if HW has antialising support

MIPS hardware may have an antialising support and it works even
page size is small.

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

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: cernekee@gmail.com
Cc: paul.gortmaker@windriver.com
Cc: kumba@gentoo.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11516/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: traps: remove unused variable
Tony Wu [Fri, 4 Dec 2015 11:41:12 +0000 (19:41 +0800)]
MIPS: traps: remove unused variable

flags is indeed unused.

Signed-off-by: Tony Wu <tung7970@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11699/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: Loongson-3: Introduce CONFIG_LOONGSON3_ENHANCEMENT
Huacai Chen [Thu, 3 Mar 2016 01:45:13 +0000 (09:45 +0800)]
MIPS: Loongson-3: Introduce CONFIG_LOONGSON3_ENHANCEMENT

New Loongson 3 CPU (since Loongson-3A R2, as opposed to Loongson-3A R1,
Loongson-3B R1 and Loongson-3B R2) has many enhancements, such as FTLB,
L1-VCache, EI/DI/Wait/Prefetch instruction, DSP/DSPv2 ASE, User Local
register, Read-Inhibit/Execute-Inhibit, SFB (Store Fill Buffer), Fast
TLB refill support, etc.

This patch introduce a config option, CONFIG_LOONGSON3_ENHANCEMENT, to
enable those enhancements which are not probed at run time. If you want
a generic kernel to run on all Loongson 3 machines, please say 'N'
here. If you want a high-performance kernel to run on new Loongson 3
machines only, please say 'Y' here.

Some additional explanations:
1) SFB locates between core and L1 cache, it causes memory access out
   of order, so writel/outl (and other similar functions) need a I/O
   reorder barrier.
2) Loongson 3 has a bug that di instruction can not save the irqflag,
   so arch_local_irq_save() is modified. Since CPU_MIPSR2 is selected
   by CONFIG_LOONGSON3_ENHANCEMENT, generic kernel doesn't use ei/di
   at all.
3) CPU_HAS_PREFETCH is selected by CONFIG_LOONGSON3_ENHANCEMENT, so
   MIPS_CPU_PREFETCH (used by uasm) probing is also put in this patch.

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Steven J . Hill <sjhill@realitydiluted.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12755/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: Loongson-3: Fast TLB refill handler
Huacai Chen [Thu, 3 Mar 2016 01:45:12 +0000 (09:45 +0800)]
MIPS: Loongson-3: Fast TLB refill handler

Loongson-3A R2 has pwbase/pwfield/pwsize/pwctl registers in CP0 (this
is very similar to HTW) and lwdir/lwpte/lddir/ldpte instructions which
can be used for fast TLB refill.

[ralf@linux-mips.org: Resolve conflict.]

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Steven J . Hill <sjhill@realitydiluted.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12754/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: Loongson: Invalidate special TLBs when needed
Huacai Chen [Thu, 3 Mar 2016 01:45:11 +0000 (09:45 +0800)]
MIPS: Loongson: Invalidate special TLBs when needed

Loongson-2 has a 4 entry itlb which is a subset of jtlb, Loongson-3 has
a 4 entry itlb and a 4 entry dtlb which are subsets of jtlb. We should
write diag register to invalidate itlb/dtlb when flushing jtlb because
itlb/dtlb are not totally transparent to software.

For Loongson-3A R2 (and newer), we should invalidate ITLB, DTLB, VTLB
and FTLB before we enable/disable FTLB.

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Steven J . Hill <sjhill@realitydiluted.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12753/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
8 years agoMIPS: Loongson-3: Set cache flush handlers to cache_noop
Huacai Chen [Thu, 3 Mar 2016 01:45:10 +0000 (09:45 +0800)]
MIPS: Loongson-3: Set cache flush handlers to cache_noop

Loongson-3 maintains cache coherency by hardware, this means:
 1) It's icache is coherent with dcache.
 2) It's dcaches don't alias (maybe depend on PAGE_SIZE).
 3) It maintains cache coherency across cores (and for DMA).

So we can skip most cache flush operations by setting relevant handlers
to `cache_noop' in `r4k_cache_init'.

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Steven J . Hill <sjhill@realitydiluted.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12752/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>