arch_mmap_rnd() uses hard-coded limits of 16MB for the randomisation
of mmap within 32bit processes and 256MB in 64bit processes. Since v4.4
other arches support tuning this value in /proc/sys/vm/mmap_rnd_bits.
Add support for this to MIPS.

Set the minimum(default) number of bits randomisation for 32bit to 8 -
which with 4k pagesize is unchanged from the current 16MB total
randomness. The minimum(default) for 64bit is 12bits, again with 4k
pagesize this is the same as the current 256MB.

This patch is necessary for MIPS32 to pass the Android CTS tests, with
the number of random bits set to 15.
Signed-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Daniel Cashman <dcashman@android.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mips@linux-mips.org
Cc: kernel-hardening@lists.openwall.com
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14617/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This activates the following functionalities:
* SMP support (used on xRX200)
* PCI support
* NAND driver
* PHY driver
* UART
* Watchdog
* USB 2.0 controller

These driver are driving different IP cores found on the supported SoCs.
Signed-off-by: NHauke Mehrtens <hauke@hauke-m.de>
Acked-by: NJohn Crispin <john@phrozen.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14628/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Just generate a configuration based on this default configuration and
store it again. This removed some old configuration options.
Signed-off-by: NHauke Mehrtens <hauke@hauke-m.de>
Acked-by: NJohn Crispin <john@phrozen.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14629/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

An empty __dtb_start to __dtb_end section might result in
initial_boot_params being null for arch/mips/ralink. This showed that the
boot process hangs indefinitely in of_scan_flat_dt().
Signed-off-by: NTobias Wolf <dev-NTEO@vplace.de>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14605/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This patch adds fw_passed_dtb to arch/mips/ralink to support
CONFIG_MIPS_RAW_APPENDED_DTB. Furthermore it adds a check that __dtb_start is
not the same address as __dtb_end.
Signed-off-by: NTobias Wolf <dev-NTEO@vplace.de>
Acked-by: NJohn Crispin <john@phrozen.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14662/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The patch adds watchdog support for Loongson1 board.
Signed-off-by: NYang Ling <gnaygnil@gmail.com>
Cc: keguang.zhang@gmail.com
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14644/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Move the RTC-related macros to regs-rtc.h.
Signed-off-by: NYang Ling <gnaygnil@gmail.com>
Cc: keguang.zhang@gmail.com
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14642/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The RESTORE_ALL_AND_RET macro is never used. Remove the dead code.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14411/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

There's no reason for the pre-r6 instruction emulation code to be
limited to uniprocessor kernels. We already emulate atomic memory access
instructions in a way that works for SMP systems, and nothing else
should be affected. Remove the artificial limitation, allowing pre-r6
instruction emulation to be used with SMP kernels.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14410/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Commit 7c151d3d ("MIPS: Make use of the ERETNC instruction on MIPS
R6") began clearing LLBit during context switches, but did so on all
systems where it is writable for unclear reasons & did so from a macro
with "software_ll_bit" in its name, which is intended to operate on the
ll_bit variable used by ll/sc emulation for old CPUs.

We do now need to clear LLBit on MIPSr6 systems where we'll use eretnc
to return to userland, but we don't need to do so on MIPSr5 systems with
a writable LLBit.

Move the clear to its own appropriately named macro, do it only for
MIPSr6 systems & comment about why.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14409/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The r2_emul_return field in struct thread_info was used in order to take
an alternate codepath when returning to userland, which (besides not
implementing certain features) effectively used the eretnc instruction
in place of eret. The difference is that eretnc doesn't clear LLBit, and
therefore doesn't cause a linked load & store sequence to fail due to
emulation like eret would.

The reason eret would usually be used to clear LLBit is so that after
context switching we ensure that a load performed by one task doesn't
influence another task. However commit 7c151d3d ("MIPS: Make use of
the ERETNC instruction on MIPS R6") which introduced the r2_emul_return
field and conditional use of eretnc also for some reason began
explicitly clearing LLBit during context switches - despite retaining
the use of eret for everything but returns from the pre-r6 instruction
emulation code.

As LLBit is cleared upon context switches anyway, simplify this by using
eretnc unconditionally for MIPSr6 kernels. This allows us to remove the
4 byte r2_emul_return boolean from struct thread_info, simplify the
return to user code in entry.S and avoid the overhead of tracking &
checking state which we don't need.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14408/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Add support for Imagination Technologies' Marduk board which is based
on Pistachio SoC. It is also known as Creator Ci40. Marduk is legacy
name and will be there for decades.

Documentation for this board can be found on
https://docs.creatordev.io/ci40/

This patch adds initial support for board with following peripherals:

* PWM based heartbeat LED
* GPIO based buttons
* SPI NOR flash on SPI1
* UART0 and UART1
* SD card
* Ethernet
* USB
* PWM
* ADC
* I2C
Signed-off-by: NRahul Bedarkar <rahul.bedarkar@imgtec.com>
Acked-by: NRob Herring <robh@kernel.org>
Acked-by: NJames Hartley <james.hartley@imgtec.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14394/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Add support for the base Device Tree for Imagination Technologies'
Pistachio SoC.

This commit supports the following peripherals:

 * Clocks
 * Pinctrl and GPIO
 * UART
 * SPI
 * I2C
 * PWM
 * ADC
 * Watchdog
 * Ethernet
 * MMC
 * DMA engine
 * Crypto
 * I2S
 * SPDIF
 * Internal DAC
 * Timer
 * USB
 * IR
 * Interrupt Controller
Signed-off-by: NRahul Bedarkar <rahul.bedarkar@imgtec.com>
Acked-by: NJames Hartley <james.hartley@imgtec.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14393/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

On systems with CM3, we must ensure that the L1 & L2 ECC enables are set
to the same value. This is presumed by the hardware & cache corruption
can occur when it is not the case. Support enabling & disabling the L2
ECC checking on CM3 systems where this is controlled via a GCR, and
ensure that it matches the state of L1 ECC checking. Remove I6400 from
the switch statement it will no longer hit, and which was incorrect
since the L2 ECC enable bit isn't in the CP0 ErrCtl register.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14413/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

MIPS instructions MULTU, MADDU and MSUBU emulation requires registers HI/LO
to be converted to signed 32bits before 64bit sign extension on MIPS64.

Bug was found on running MIPS32 R2 test application on MIPS64 R6 kernel.

Fixes: b0a668fb ("MIPS: kernel: mips-r2-to-r6-emul: Add R2 emulator for MIPS R6")
Signed-off-by: NLeonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Reported-by: Nikola.Veljkovic@imgtec.com
Cc: paul.burton@imgtec.com
Cc: yamada.masahiro@socionext.com
Cc: akpm@linux-foundation.org
Cc: andrea.gelmini@gelma.net
Cc: macro@imgtec.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14043/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This patch changes DEFAULT_MEMSIZE to 64MB
which is the memory size of latest EVB.
Signed-off-by: NKelvin Cheung <keguang.zhang@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13856/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This patch removes ARCH_WANT_OPTIONAL_GPIOLIB due to upstream changes.
Signed-off-by: NKelvin Cheung <keguang.zhang@gmail.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Cc: Yang Ling <gnaygnil@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13855/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

While we properly disabled the per-CPU timer interrupt, we also need to
make sure that all interrupts that can possibly have this CPU in their
smp_affinity mask also have a chance to see this interrupt migrated to a
CPU not being taken offline.

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

Fixes: 230b6ff5 ("MIPS: BMIPS: Mask off timer IRQs when hot-unplugging a CPU")
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Cc: cernekee@gmail.com
Cc: jaedon.shin@gmail.com
Cc: justinpopo6@gmail.com
Cc: tglx@linutronix.de
Cc: marc.zyngier@arm.com
Cc: jason@lakedaemon.net
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14488/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Update defconfig to enable emaclite, i2c and temp sensor on the
xilfpga platform
Signed-off-by: NZubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14595/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The xilfpga platform has a Xilinx AXI emaclite block.

Add the DT node to use it.
Signed-off-by: NZubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14596/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The xilfpga platform has an AXI I2C Bus master with a temperature
sensor connected to it.

Add the device tree node to use them.
Signed-off-by: NZubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14594/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Update the DT node with the UART irq
Signed-off-by: NZubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14593/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

IRQs from peripherals such as i2c/uart/ethernet come via
the AXI Interrupt controller.

Select it in Kconfig for xilfpga and add the DT node
Signed-off-by: NZubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14592/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This prepares the code to use the Xilinx Interrupt Controller
driver in drivers/irqchip/irq-xilinx-intc.c
Signed-off-by: NZubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: Zubair.Kakakhel@imgtec.com
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14591/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

'clk_register_fixed_rate()' returns an error pointer in case of error, not
NULL. So test it with IS_ERR.
Signed-off-by: NChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: NAban Bedel <albeu@free.fr>
Cc: antonynpavlov@gmail.com
Cc: hackpascal@gmail.com
Cc: amitoj1606@gmail.com
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: kernel-janitors@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14464/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

If there is no online CPU within a core which could receive the IPI to
start another VP in that core, a BUG() is triggered. Instead print a
warning and gracefully handle the failure such that the system remains
usable, albeit without the requested secondary CPU.
Signed-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Qais Yousef <qsyousef@gmail.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/14504/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The previous commit made cpu_callin_map redundant, since it is no longer
used to signal secondary CPUs starting, or going offline. Remove it now.
Signed-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Qais Yousef <qsyousef@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: Yang Shi <yang.shi@windriver.com>
Cc: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14503/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

If a secondary CPU failed to start, for any reason, the CPU requesting
the secondary to start would get stuck in the loop waiting for the
secondary to be present in the cpu_callin_map.

Rather than that, use a completion event to signal that the secondary
CPU has started and is waiting to synchronise counters.

Since the CPU presence will no longer be marked in cpu_callin_map,
remove the redundant test from arch_cpu_idle_dead().
Signed-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Qais Yousef <qsyousef@gmail.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Marcin Nowakowski <marcin.nowakowski@imgtec.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/14502/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Code in arch/mips/netlogic/common/irq.c which handles the XLP PIC fails
to build in XLR configurations due to cpu_is_xlp9xx not being defined,
leading to the following build failure:

    arch/mips/netlogic/common/irq.c: In function ‘xlp_of_pic_init’:
    arch/mips/netlogic/common/irq.c:298:2: error: implicit declaration
    of function ‘cpu_is_xlp9xx’ [-Werror=implicit-function-declaration]
      if (cpu_is_xlp9xx()) {
      ^

Although the code was conditional upon CONFIG_OF which is indirectly
selected by CONFIG_NLM_XLP_BOARD but not CONFIG_NLM_XLR_BOARD, the
failing XLR with CONFIG_OF configuration can be configured manually or
by randconfig.

Fix the build failure by making the affected XLP PIC code conditional
upon CONFIG_CPU_XLP which is used to guard the inclusion of
asm/netlogic/xlp-hal/xlp.h that provides the required cpu_is_xlp9xx
function.

[ralf@linux-mips.org: Fixed up as per Jayachandran's suggestion.]
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: Jayachandran C <jchandra@broadcom.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14524/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

We have a HIGHMEM_DEBUG macro defined in asm/highmem.h with a comment
stating that it should be removed for production, and no users... Kill
it.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14523/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

When relocatable support for MIPS was merged, there was no support for
an architecture to add a postlink step for vmlinux. This meant that only
invoking a target within the boot directory, such as uImage, caused the
relocations to be inserted into vmlinux. Building just the vmlinux
target would result in a relocatable kernel with no relocation
information present.

Commit fbe6e37d ("kbuild: add arch specific post-link Makefile")
recified this situation, so MIPS can now define a postlink step to add
relocation information into vmlinux, and remove the additional steps
tacked onto boot targets.
Signed-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Tested-by: NSteven J. Hill <steven.hill@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14554/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

is_jump_ins() checks for plain jump ("j") instructions since commit
e7438c4b ("MIPS: Fix sibling call handling in get_frame_info") but
that commit didn't make the same change to the microMIPS code, leaving
it inconsistent with the MIPS32/MIPS64 code. Handle the microMIPS
encoding of the jump instruction too such that it behaves consistently.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Fixes: e7438c4b ("MIPS: Fix sibling call handling in get_frame_info")
Cc: Tony Wu <tung7970@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # v3.10+
Patchwork: https://patchwork.linux-mips.org/patch/14533/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

get_frame_info() calculates the offset of the return address within a
stack frame simply by dividing a the bottom 16 bits of the instruction,
treated as a signed integer, by the size of a long. Whilst this works
for MIPS32 & MIPS64 ISAs where the sw or sd instructions are used, it's
incorrect for microMIPS where encodings differ. The result is that we
typically completely fail to unwind the stack on microMIPS.

Fix this by adjusting is_ra_save_ins() to calculate the return address
offset, and take into account the various different encodings there in
the same place as we consider whether an instruction is storing the
ra/$31 register.

With this we are now able to unwind the stack for kernels targetting the
microMIPS ISA, for example we can produce:

    Call Trace:
    [<80109e1f>] show_stack+0x63/0x7c
    [<8011ea17>] __warn+0x9b/0xac
    [<8011ea45>] warn_slowpath_fmt+0x1d/0x20
    [<8013fe53>] register_console+0x43/0x314
    [<8067c58d>] of_setup_earlycon+0x1dd/0x1ec
    [<8067f63f>] early_init_dt_scan_chosen_stdout+0xe7/0xf8
    [<8066c115>] do_early_param+0x75/0xac
    [<801302f9>] parse_args+0x1dd/0x308
    [<8066c459>] parse_early_options+0x25/0x28
    [<8066c48b>] parse_early_param+0x2f/0x38
    [<8066e8cf>] setup_arch+0x113/0x488
    [<8066c4f3>] start_kernel+0x57/0x328
    ---[ end trace 0000000000000000 ]---

Whereas previously we only produced:

    Call Trace:
    [<80109e1f>] show_stack+0x63/0x7c
    ---[ end trace 0000000000000000 ]---
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Fixes: 34c2f668 ("MIPS: microMIPS: Add unaligned access support.")
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # v3.10+
Patchwork: https://patchwork.linux-mips.org/patch/14532/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

is_jump_ins() checks 16b instruction fields without verifying that the
instruction is indeed 16b, as is done by is_ra_save_ins() &
is_sp_move_ins(). Add the appropriate check.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Fixes: 34c2f668 ("MIPS: microMIPS: Add unaligned access support.")
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # v3.10+
Patchwork: https://patchwork.linux-mips.org/patch/14531/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

get_frame_info() is meant to iterate over up to the first 128
instructions within a function, but for microMIPS kernels it will not
reach that many instructions unless the function is 512 bytes long since
we calculate the maximum number of instructions to check by dividing the
function length by the 4 byte size of a union mips_instruction. In
microMIPS kernels this won't do since instructions are variable length.

Fix this by instead checking whether the pointer to the current
instruction has reached the end of the function, and use max_insns as a
simple constant to check the number of iterations against.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Fixes: 34c2f668 ("MIPS: microMIPS: Add unaligned access support.")
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # v3.10+
Patchwork: https://patchwork.linux-mips.org/patch/14530/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

During stack unwinding we call a number of functions to determine what
type of instruction we're looking at. The union mips_instruction pointer
provided to them may be pointing at a 2 byte, but not 4 byte, aligned
address & we thus cannot directly access the 4 byte wide members of the
union mips_instruction. To avoid this is_ra_save_ins() copies the
required half-words of the microMIPS instruction to a correctly aligned
union mips_instruction on the stack, which it can then access safely.
The is_jump_ins() & is_sp_move_ins() functions do not correctly perform
this temporary copy, and instead attempt to directly dereference 4 byte
fields which may be misaligned and lead to an address exception.

Fix this by copying the instruction halfwords to a temporary union
mips_instruction in get_frame_info() such that we can provide a 4 byte
aligned union mips_instruction to the is_*_ins() functions and they do
not need to deal with misalignment themselves.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Fixes: 34c2f668 ("MIPS: microMIPS: Add unaligned access support.")
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # v3.10+
Patchwork: https://patchwork.linux-mips.org/patch/14529/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

get_frame_info() can be called in microMIPS kernels with the ISA bit
already clear. For example this happens when unwind_stack_by_address()
is called because we begin with a PC that has the ISA bit set & subtract
the (odd) offset from the preceding symbol (which does not have the ISA
bit set). Since get_frame_info() unconditionally subtracts 1 from the PC
in microMIPS kernels it incorrectly misaligns the address it then
attempts to access code at, leading to an address error exception.

Fix this by using msk_isa16_mode() to clear the ISA bit, which allows
get_frame_info() to function regardless of whether it is provided with a
PC that has the ISA bit set or not.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Fixes: 34c2f668 ("MIPS: microMIPS: Add unaligned access support.")
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # v3.10+
Patchwork: https://patchwork.linux-mips.org/patch/14528/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The MIPS-specific asm/unaligned.h provides nothing that the generic
version doesn't - it simply uses MIPS-specific endianness macros in
place of generic ones & lacks support for
CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS. Remove it & switch to using the
generic version to remove duplication.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Reviewed-by: NJames Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14412/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

When clearing the .bss section in kernel_entry we do so using LONG_S
instructions, and branch whilst the current write address doesn't equal
the end of the .bss section minus the size of a long integer. The .bss
section always begins at a long-aligned address and we always increment
the write pointer by the size of a long integer - we therefore rely upon
the .bss section ending at a long-aligned address. If this is not the
case then the long-aligned write address can never be equal to the
non-long-aligned end address & we will continue to increment past the
end of the .bss section, attempting to zero the rest of memory.

Despite this requirement that .bss end at a long-aligned address we pass
0 as the end alignment requirement to the BSS_SECTION macro and thus
don't guarantee any particular alignment, allowing us to hit the error
condition described above.

Fix this by instead passing 8 bytes as the end alignment argument to
the BSS_SECTION macro, ensuring that the end of the .bss section is
always at least long-aligned.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14526/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This hook provides the platform the chance to perform any required
setup before the boot processor switches to the relocated kernel.
The relocated kernel has been copied and fixed up ready for execution
at this point. Secondary CPUs may wish to switch to it early. There
is also the opportunity for the platform to abort jumping to the
relocated kernel if there is anything wrong with the chosen offset.
Signed-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Signed-off-by: NSteven J. Hill <Steven.Hill@cavium.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14651/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>