Commit 29bb45f25f (regmap-mmio: Use native endianness for read/write)
attempted to fix some long standing bugs in the MMIO implementation for
big endian systems caused by duplicate byte swapping in both regmap and
readl()/writel() which affected MIPS systems as when they are in big
endian mode they flip the endianness of all registers in the system, not
just the CPU. MIPS systems had worked around this by declaring regmap
using IPs as little endian which is inaccurate, unfortunately the issue
had not been reported.
Sadly the fix makes things worse rather than better. By changing the
behaviour to match the documentation it caused behaviour changes for
other IPs which broke them and by using the __raw I/O accessors to avoid
the endianness swapping in readl()/writel() it removed some memory
ordering guarantees and could potentially generate unvirtualisable
instructions on some architectures.
Unfortunately sorting out all this mess in any half way sensible fashion
was far too invasive to go in during an -rc cycle so instead let's go
back to the old broken behaviour for v4.5, the better fixes are already
queued for v4.6. This does mean that we keep the broken MIPS DTs for
another release but that seems the least bad way of handling the
situation.
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Merge tag 'regmap-fix-v4.5-big-endian' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap
Pull regmap fix from Mark Brown:
"A single revert back to v4.4 endianness handling.
Commit 29bb45f25f ("regmap-mmio: Use native endianness for
read/write") attempted to fix some long standing bugs in the MMIO
implementation for big endian systems caused by duplicate byte
swapping in both regmap and readl()/writel(). Sadly the fix makes
things worse rather than better, so revert it for now"
* tag 'regmap-fix-v4.5-big-endian' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
regmap: mmio: Revert to v4.4 endianness handling
Commit 29bb45f25f (regmap-mmio: Use native endianness for read/write)
attempted to fix some long standing bugs in the MMIO implementation for
big endian systems caused by duplicate byte swapping in both regmap and
readl()/writel() which affected MIPS systems as when they are in big
endian mode they flip the endianness of all registers in the system, not
just the CPU. MIPS systems had worked around this by declaring regmap
using IPs as little endian which is inaccurate, unfortunately the issue
had not been reported.
Sadly the fix makes things worse rather than better. By changing the
behaviour to match the documentation it caused behaviour changes for
other IPs which broke them and by using the __raw I/O accessors to avoid
the endianness swapping in readl()/writel() it removed some memory
ordering guarantees and could potentially generate unvirtualisable
instructions on some architectures.
Unfortunately sorting out all this mess in any half way sensible fashion
was far too invasive to go in during an -rc cycle so instead let's go
back to the old broken behaviour for v4.5, the better fixes are already
queued for v4.6. This does mean that we keep the broken MIPS DTs for
another release but that seems the least bad way of handling the
situation.
Reported-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Mark Brown <broonie@kernel.org>
This reverts commit 5bdb102b3f.
Brian Norris <computersforpeace@gmail.com> is reporting:
Ralf,
Please revert this and send it to Linus (or else, I can send it myself).
This is causing build failures, because I didn't take the rest of
Simon's series yet.
drivers/mtd/bcm63xxpart.c: In function 'bcm63xx_parse_cfe_partitions':
drivers/mtd/bcm63xxpart.c:93:2: error: implicit declaration of function
'bcm63xx_nvram_get_psi_size' [-Werror=implicit-function-declaration]
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
References: https://www.linux-mips.org/cgi-bin/mesg.cgi?a=linux-mips&i=20160126191607.GA111152%40google.com
Pull MIPS updates from Ralf Baechle:
"This is the main pull request for MIPS for 4.5 plus some 4.4 fixes.
The executive summary:
- ATH79 platform improvments, use DT bindings for the ATH79 USB PHY.
- Avoid useless rebuilds for zboot.
- jz4780: Add NEMC, BCH and NAND device tree nodes
- Initial support for the MicroChip's DT platform. As all the device
drivers are missing this is still of limited use.
- Some Loongson3 cleanups.
- The unavoidable whitespace polishing.
- Reduce clock skew when synchronizing the CPU cycle counters on CPU
startup.
- Add MIPS R6 fixes.
- Lots of cleanups across arch/mips as fallout from KVM.
- Lots of minor fixes and changes for IEEE 754-2008 support to the
FPU emulator / fp-assist software.
- Minor Ralink, BCM47xx and bcm963xx platform support improvments.
- Support SMP on BCM63168"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (84 commits)
MIPS: zboot: Add support for serial debug using the PROM
MIPS: zboot: Avoid useless rebuilds
MIPS: BMIPS: Enable ARCH_WANT_OPTIONAL_GPIOLIB
MIPS: bcm63xx: nvram: Remove unused bcm63xx_nvram_get_psi_size() function
MIPS: bcm963xx: Update bcm_tag field image_sequence
MIPS: bcm963xx: Move extended flash address to bcm_tag header file
MIPS: bcm963xx: Move Broadcom BCM963xx image tag data structure
MIPS: bcm63xx: nvram: Use nvram structure definition from header file
MIPS: bcm963xx: Add Broadcom BCM963xx board nvram data structure
MAINTAINERS: Add KVM for MIPS entry
MIPS: KVM: Add missing newline to kvm_err()
MIPS: Move KVM specific opcodes into asm/inst.h
MIPS: KVM: Use cacheops.h definitions
MIPS: Break down cacheops.h definitions
MIPS: Use EXCCODE_ constants with set_except_vector()
MIPS: Update trap codes
MIPS: Move Cause.ExcCode trap codes to mipsregs.h
MIPS: KVM: Make kvm_mips_{init,exit}() static
MIPS: KVM: Refactor added offsetof()s
MIPS: KVM: Convert EXPORT_SYMBOL to _GPL
...
As most platforms implement the PROM serial interface prom_putchar()
add a simple bridge to allow re-using this code for zboot.
Signed-off-by: Alban Bedel <albeu@free.fr>
Cc: Alex Smith <alex.smith@imgtec.com>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11811/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add dummy.o to the targets list, and fill targets automatically from
$(vmlinuzobjs) to avoid having to maintain two lists.
When building with XZ compression copy ashldi3.c to the build
directory to use a different object file for the kernel and zboot.
Without this the same object file need to be build with different
flags which cause a rebuild at every run.
Signed-off-by: Alban Bedel <albeu@free.fr>
Cc: linux-mips@linux-mips.org
Cc: Alex Smith <alex.smith@imgtec.com>
Cc: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11810/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Remove bcm63xx_nvram_get_psi_size() as it now has no users.
Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Jonas Gorski <jogo@openwrt.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Cc: MIPS Mailing List <linux-mips@linux-mips.org>
Cc: MTD Maling List <linux-mtd@lists.infradead.org>
Patchwork: https://patchwork.linux-mips.org/patch/11836/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Move Broadcom BCM963xx image tag data structure to include/linux/
so that drivers outside of mach-bcm63xx can use it.
Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Jonas Gorski <jogo@openwrt.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Cc: MIPS Mailing List <linux-mips@linux-mips.org>
Cc: MTD Maling List <linux-mtd@lists.infradead.org>
Patchwork: https://patchwork.linux-mips.org/patch/11832/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Use the common definition of the nvram structure from the header file
include/linux/bcm963xx_nvram.h instead of maintaining a separate copy.
Read the version 5 size of nvram data from memory and then call the
new checksum verification function from the header file.
Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Jonas Gorski <jogo@openwrt.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Cc: MIPS Mailing List <linux-mips@linux-mips.org>
Cc: MTD Maling List <linux-mtd@lists.infradead.org>
Patchwork: https://patchwork.linux-mips.org/patch/11831/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The header arch/mips/kvm/opcode.h defines a few extra opcodes which
aren't in arch/mips/include/uapi/asm/inst.h. There's nothing KVM
specific about them, so lets move them into inst.h where they belong and
delete the header.
Note that mfmcz_op is renamed to mfmc0_op to match the instruction set
manual, and wait_op was already added to inst.h in commit b0a3eae2b9
("MIPS: inst.h: define COP0 wait op"), merged in v3.16-rc1.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11895/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Drop the custom cache operation code definitions used by KVM for
emulating guest CACHE instructions, and switch to use the existing
definitions in <asm/cacheops.h>.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11893/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Most of the cache op codes defined in cacheops.h are split into a 2-bit
cache identifier, and a 3-bit cache op code which does largely the same
thing semantically regardless of the cache identifier.
To allow the use of these definitions by KVM for decoding cache ops,
break the definitions down into parts where it makes sense to do so, and
add masks for the Cache and Op field within the cache op.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11892/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The first argument to set_except_vector is the ExcCode, which we now
have definitions for. Lets make use of them.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11894/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add a few missing trap codes.
[ralf@linux-mips.org: Drop removal of exception codes. I don't care what
the incomplete architecture spec says; it can't change existing hardware
and VCEI is supported indeed.]
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11890/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Move the Cause.ExcCode trap code definitions from kvm_host.h to
mipsregs.h, since they describe architectural bits rather than KVM
specific constants, and change the prefix from T_ to EXCCODE_.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11891/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The module init and exit functions have no need to be global, so make
them static.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11889/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
When calculating the offsets into the commpage for dynamically
translated mtc0/mfc0 guest instructions, multiple offsetof()s are added
together to find the offset of the specific register in the mips_coproc,
within the commpage.
Simplify each of these cases to a single offsetof() to find the offset
of the specific register within the commpage.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11888/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Export symbols only to GPL modules to match other KVM symbols in
virt/kvm/ and arch/*/kvm/.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11887/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The function kvm_mips_host_tlb_inv_index() is unused, so drop it
completely.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11886/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The CAUSEB_DC and CAUSEF_DC definitions used by KVM are defined in
asm/kvm_host.h, but all the other Cause register field definitions are
found in asm/mipsregs.h.
Lets reunite the DC bit definitions with its friends in mipsregs.h.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11885/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Some definitions in the MIPS asm/kvm_host.h are completely unused, so
lets drop them.
MS_TO_NS is no longer used since commit e30492bbe9 ("MIPS: KVM:
Rewrite count/compare timer emulation"). The others don't appear ever to
have been used.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11884/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This adds basic DTS configuration for the PIC32MZDA chip and in turn the
PIC32MZDA Starter Kit.
Signed-off-by: Joshua Henderson <joshua.henderson@microchip.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Kumar Gala <galak@codeaurora.org>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Paul Burton <paul.burton@imgtec.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/12104/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This adds support for the Microchip PIC32 MIPS microcontroller with the
specific variant PIC32MZDA. PIC32MZDA is based on the MIPS m14KEc core
and boots using device tree.
This includes an early pin setup and early clock setup needed prior to
device tree being initialized. In additon, an interface is provided to
synchronize access to registers shared across several peripherals.
Signed-off-by: Joshua Henderson <joshua.henderson@microchip.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12097/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The cp0_tcstatus member of struct pt_regs was removed along with the
rest of SMTC in v3.16, commit b633648c5a ("MIPS: MT: Remove SMTC
support"), however recent uprobes support in v4.3 added back a reference
to it in the regoffset_table[] in ptrace.c. Remove it.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Fixes: 40e084a506 ("MIPS: Add uprobes support.")
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11920/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
As we want gpio_chip .get() calls to be able to return negative
error codes and propagate to drivers, we need to go over all
drivers and make sure their return values are clamped to [0,1].
We do this by using the ret = !!(val) design pattern.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-mips@linux-mips.org
Cc: linux-gpio@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11925/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
As we want gpio_chip .get() calls to be able to return negative
error codes and propagate to drivers, we need to go over all
drivers and make sure their return values are clamped to [0,1].
We do this by using the ret = !!(val) design pattern.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-mips@linux-mips.org
Cc: linux-gpio@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11924/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
As we want gpio_chip .get() calls to be able to return negative
error codes and propagate to drivers, we need to go over all
drivers and make sure their return values are clamped to [0,1].
We do this by using the ret = !!(val) design pattern.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-mips@linux-mips.org
Cc: linux-gpio@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11923/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
As we want gpio_chip .get() calls to be able to return negative
error codes and propagate to drivers, we need to go over all
drivers and make sure their return values are clamped to [0,1].
We do this by using the ret = !!(val) design pattern.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: Alban Bedel <albeu@free.fr>
Cc: linux-mips@linux-mips.org
Cc: linux-gpio@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11922/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
As we want gpio_chip .get() calls to be able to return negative
error codes and propagate to drivers, we need to go over all
drivers and make sure their return values are clamped to [0,1].
We do this by using the ret = !!(val) design pattern.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-mips@linux-mips.org
Cc: linux-gpio@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11921/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Change the CONFIG_MIPS_CMDLINE_EXTEND to CONFIG_MIPS_CMDLINE_DTB_EXTEND
to resolve the EXTEND_WITH_PROM macro.
Signed-off-by: Jaedon Shin <jaedon.shin@gmail.com>
Fixes: 2024972ef5 ("MIPS: Make the kernel arguments from dtb available")
Reviewed-by: Alexander Sverdlin <alexander.svedlin@gmail.com>
Cc: Jonas Gorski <jogo@openwrt.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Aaro Koskinen <aaro.koskinen@nokia.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11909/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The kernel currently assumes that a core will start up in legacy mode
using the exception base provided through the CM GCR registers. If a
core has been configured in hardware to start in EVA mode, these
assumptions will fail.
This patch ensures that secondary cores are initialized to meet these
assumptions.
Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11907/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Fix the description of the microMIPS NOP16 encoding or MM_NOP16, which
is not equivalent to the MIPS16 NOP instruction. This is 0x0c00 and
represents the microMIPS `MOVE16 $0, $0' operation, whereas MIPS16 NOP
is encoded as 0x6500, representing `MOVE $0, $16'.
Also fix a typo in `mm_fp0_format' description.
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12177/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Remove irrelevant content from the description of the emulation frame in
`mips_dsemul', referring to bare-metal configurations. Update the text,
reflecting the change made with commit ba3049ed40 ("MIPS: Switch FPU
emulator trap to BREAK instruction."), where we switched from using an
address error exception on an unaligned access to the use of a BREAK 514
instruction causing a breakpoint exception instead.
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12176/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Emulate the microMIPS ADDIUPC instruction directly in `mips_dsemul'. If
executed in the emulation frame, this instruction produces an incorrect
result, because the value of the PC there is not the same as where the
instruction originated.
Reshape code so as to handle all microMIPS cases together.
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12175/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Complement commit 102cedc32a ("MIPS: microMIPS: Floating point
support.") which introduced microMIPS FPU emulation, but did not adjust
the encoding of the BREAK instruction used to terminate the branch delay
slot emulation frame. Consequently the execution of any such frame is
indeterminate and, depending on CPU configuration, will result in random
code execution or an offending program being terminated with SIGILL.
This is because the regular MIPS BREAK instruction is encoded with the 0
major and the 0xd minor opcode, however in the microMIPS instruction set
this major/minor opcode pair denotes an encoding reserved for the DSP
ASE. Instead the microMIPS BREAK instruction is encoded with the 0
major and the 0x7 minor opcode.
Use the correct BREAK encoding for microMIPS FPU emulation then.
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12174/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Correct formatting breakage introduced with commit 102cedc32a ("MIPS:
microMIPS: Floating point support."), so that further changes to this
code can be consistent.
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12173/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Fix an issue introduced with commit 9ab4471c9f ("MIPS: math-emu:
Correct delay-slot exception propagation") where the emulation of a NOP
instruction signals the need to terminate the emulation loop. This in
turn, if the PC has not changed from the entry to the loop, will cause
the kernel to terminate the program with SIGILL.
Consider this program:
static double div(double d)
{
do
d /= 2.0;
while (d > .5);
return d;
}
int main(int argc, char **argv)
{
return div(argc);
}
which gets compiled to the following binary code:
00400490 <main>:
400490: 44840000 mtc1 a0,$f0
400494: 3c020040 lui v0,0x40
400498: d44207f8 ldc1 $f2,2040(v0)
40049c: 46800021 cvt.d.w $f0,$f0
4004a0: 46220002 mul.d $f0,$f0,$f2
4004a4: 4620103c c.lt.d $f2,$f0
4004a8: 4501fffd bc1t 4004a0 <main+0x10>
4004ac: 00000000 nop
4004b0: 4620000d trunc.w.d $f0,$f0
4004b4: 03e00008 jr ra
4004b8: 44020000 mfc1 v0,$f0
4004bc: 00000000 nop
Where the FPU emulator is used, depending on the number of command-line
arguments this code will either run to completion or terminate with
SIGILL.
If no arguments are specified, then BC1T will not be taken, NOP will not
be emulated and code will complete successfully.
If one argument is specified, then BC1T will be taken once and NOP will
be emulated. At this point the entry PC value will be 0x400498 and the
new PC value, set by `mips_dsemul' will be 0x4004a0, the target of BC1T.
The emulation loop will terminate, but SIGILL will not be issued,
because the PC has changed. The FPU emulator will be entered again and
on the second execution BC1T will not be taken, NOP will not be emulated
and code will complete successfully.
If two or more arguments are specified, then the first execution of BC1T
will proceed as above. Upon reentering the FPU emulator the emulation
loop will continue to BC1T, at which point the branch will be taken and
NOP emulated again. At this point however the entry PC value will be
0x4004a0, the same as the target of BC1T. This will make the emulator
conclude that execution has not advanced and therefore an unsupported
FPU instruction has been encountered, and SIGILL will be sent to the
process.
Fix the problem by extending the internal API of `mips_dsemul', making
it return -1 if no delay slot emulation frame has been made, the
instruction has been handled and execution of the emulation loop needs
to continue as if nothing happened. Remove code from `mips_dsemul' to
reproduce steps made by the emulation loop at the conclusion of each
iteration, as those will be reached normally now. Adjust call sites
accordingly. Document the API.
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12172/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Commit be0c37c985 (MIPS: Rearrange PTE bits into fixed positions.)
defines fixed PTE bits for MIPS R2. Then, commit d7b631419b
(MIPS: pgtable-bits: Fix XPA damage to R6 definitions.) adds the MIPS
R6 definitions in the same way as MIPS R2. But some R6 #ifdefs in the
later commit are missing, so in this patch I fix that.
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12164/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
While synchronization, count register will go backwards for the master.
If synchronise_count_master() runs before synchronise_count_slave(),
skew becomes even more. The skew is very harmful for CPU hotplug (CPU0
do synchronization with CPU1, then CPU0 do synchronization with CPU2
and CPU0's count goes backwards, so it will be out of sync with CPU1).
After the commit cf9bfe55f2 (MIPS: Synchronize MIPS count one
CPU at a time), we needn't evaluate count_reference at the beginning of
synchronise_count_master() any more. Thus, we evaluate the initcount (It
seems like count_reference is redundant) in the 2nd loop. Since we write
the count register in the last loop, we don't need additional barriers
(the existing memory barriers are enough).
Moreover, I think we loop 3 times is enough to get a primed instruction
cache, this can also get less skew than looping 5 times.
Comments are also updated in this patch.
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/12163/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This reverts commit 22b1452399.
It was originally sent in an earlier revision of the pfn_t patchset.
Besides being broken, the warning is also fixed by PFN_FLAGS_MASK
casting the PAGE_MASK to an unsigned long.
Reported-by: Manuel Lauss <manuel.lauss@gmail.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Cc: linux-kernel@vger.kernel.org
Cc: Linux-MIPS <linux-mips@linux-mips.org>
Cc: stable@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12182/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This patch is borrowed from x86 hpet driver and explaind below:
Due to the overly intelligent design of HPETs, we need to workaround
the problem that the compare value which we write is already behind
the actual counter value at the point where the value hits the real
compare register. This happens for two reasons:
1) We read out the counter, add the delta and write the result to the
compare register. When a NMI hits between the read out and the write
then the counter can be ahead of the event already.
2) The write to the compare register is delayed by up to two HPET
cycles in AMD chipsets.
We can work around this by reading back the compare register to make
sure that the written value has hit the hardware. But that is bad
performance wise for the normal case where the event is far enough in
the future.
As we already know that the write can be delayed by up to two cycles
we can avoid the read back of the compare register completely if we
make the decision whether the delta has elapsed already or not based
on the following calculation:
cmp = event - actual_count;
If cmp is less than 64 HPET clock cycles, then we decide that the event
has happened already and return -ETIME. That covers the above #1 and #2
problems which would cause a wait for HPET wraparound (~306 seconds).
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12162/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
