Microblaze is an FPGA soft core that can be configured various ways.
If it is configured without a multiplier, the standard __hash_32()
will require a call to __mulsi3, which is a slow software loop.
Instead, use a shift-and-add sequence for the constant multiply.
GCC knows how to do this, but it's not as clever as some.
Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Cc: Alistair Francis <alistair.francis@xilinx.com>
Cc: Michal Simek <michal.simek@xilinx.com>
This provides a multiply by constant GOLDEN_RATIO_32 = 0x61C88647
for the original mc68000, which lacks a 32x32-bit multiply instruction.
Yes, the amount of optimization effort put in is excessive. :-)
Shift-add chain found by Yevgen Voronenko's Hcub algorithm at
http://spiral.ece.cmu.edu/mcm/gen.html
Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Andreas Schwab <schwab@linux-m68k.org>
Cc: Philippe De Muyter <phdm@macq.eu>
Cc: linux-m68k@lists.linux-m68k.org
This is just the infrastructure; there are no users yet.
This is modelled on CONFIG_ARCH_RANDOM; a CONFIG_ symbol declares
the existence of <asm/hash.h>.
That file may define its own versions of various functions, and define
HAVE_* symbols (no CONFIG_ prefix!) to suppress the generic ones.
Included is a self-test (in lib/test_hash.c) that verifies the basics.
It is NOT in general required that the arch-specific functions compute
the same thing as the generic, but if a HAVE_* symbol is defined with
the value 1, then equality is tested.
Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Andreas Schwab <schwab@linux-m68k.org>
Cc: Philippe De Muyter <phdm@macq.eu>
Cc: linux-m68k@lists.linux-m68k.org
Cc: Alistair Francis <alistai@xilinx.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: uclinux-h8-devel@lists.sourceforge.jp
Patch 0fed3ac866 improved the hash mixing, but the function is slower
than necessary; there's a 7-instruction dependency chain (10 on x86)
each loop iteration.
Word-at-a-time access is a very tight loop (which is good, because
link_path_walk() is one of the hottest code paths in the entire kernel),
and the hash mixing function must not have a longer latency to avoid
slowing it down.
There do not appear to be any published fast hash functions that:
1) Operate on the input a word at a time, and
2) Don't need to know the length of the input beforehand, and
3) Have a single iterated mixing function, not needing conditional
branches or unrolling to distinguish different loop iterations.
One of the algorithms which comes closest is Yann Collet's xxHash, but
that's two dependent multiplies per word, which is too much.
The key insights in this design are:
1) Barring expensive ops like multiplies, to diffuse one input bit
across 64 bits of hash state takes at least log2(64) = 6 sequentially
dependent instructions. That is more cycles than we'd like.
2) An operation like "hash ^= hash << 13" requires a second temporary
register anyway, and on a 2-operand machine like x86, it's three
instructions.
3) A better use of a second register is to hold a two-word hash state.
With careful design, no temporaries are needed at all, so it doesn't
increase register pressure. And this gets rid of register copying
on 2-operand machines, so the code is smaller and faster.
4) Using two words of state weakens the requirement for one-round mixing;
we now have two rounds of mixing before cancellation is possible.
5) A two-word hash state also allows operations on both halves to be
done in parallel, so on a superscalar processor we get more mixing
in fewer cycles.
I ended up using a mixing function inspired by the ChaCha and Speck
round functions. It is 6 simple instructions and 3 cycles per iteration
(assuming multiply by 9 can be done by an "lea" instruction):
x ^= *input++;
y ^= x; x = ROL(x, K1);
x += y; y = ROL(y, K2);
y *= 9;
Not only is this reversible, two consecutive rounds are reversible:
if you are given the initial and final states, but not the intermediate
state, it is possible to compute both input words. This means that at
least 3 words of input are required to create a collision.
(It also has the property, used by hash_name() to avoid a branch, that
it hashes all-zero to all-zero.)
The rotate constants K1 and K2 were found by experiment. The search took
a sample of random initial states (I used 1023) and considered the effect
of flipping each of the 64 input bits on each of the 128 output bits two
rounds later. Each of the 8192 pairs can be considered a biased coin, and
adding up the Shannon entropy of all of them produces a score.
The best-scoring shifts also did well in other tests (flipping bits in y,
trying 3 or 4 rounds of mixing, flipping all 64*63/2 pairs of input bits),
so the choice was made with the additional constraint that the sum of the
shifts is odd and not too close to the word size.
The final state is then folded into a 32-bit hash value by a less carefully
optimized multiply-based scheme. This also has to be fast, as pathname
components tend to be short (the most common case is one iteration!), but
there's some room for latency, as there is a fair bit of intervening logic
before the hash value is used for anything.
(Performance verified with "bonnie++ -s 0 -n 1536:-2" on tmpfs. I need
a better benchmark; the numbers seem to show a slight dip in performance
between 4.6.0 and this patch, but they're too noisy to quote.)
Special thanks to Bruce fields for diligent testing which uncovered a
nasty fencepost error in an earlier version of this patch.
[checkpatch.pl formatting complaints noted and respectfully disagreed with.]
Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Tested-by: J. Bruce Fields <bfields@redhat.com>
The "simplified" prime multipliers made very bad hash functions, so get rid
of them. This completes the work of 689de1d6ca.
To avoid the inefficiency which was the motivation for the "simplified"
multipliers, hash_64() on 32-bit systems is changed to use a different
algorithm. It makes two calls to hash_32() instead.
drivers/media/usb/dvb-usb-v2/af9015.c uses the old GOLDEN_RATIO_PRIME_32
for some horrible reason, so it inherits a copy of the old definition.
Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Cc: Antti Palosaari <crope@iki.fi>
Cc: Mauro Carvalho Chehab <m.chehab@samsung.com>
That's all that's ever asked for, and it makes the return
type of hash_long() consistent.
It also allows (upcoming patch) an optimized implementation
of hash_64 on 32-bit machines.
I tried adding a BUILD_BUG_ON to ensure the number of bits requested
was never more than 32 (most callers use a compile-time constant), but
adding <linux/bug.h> to <linux/hash.h> breaks the tools/perf compiler
unless tools/perf/MANIFEST is updated, and understanding that code base
well enough to update it is too much trouble. I did the rest of an
allyesconfig build with such a check, and nothing tripped.
Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Finally, the first use of previous two patches: eliminate the
separate ad-hoc string hash functions in the sunrpc code.
Now hash_str() is a wrapper around hash_string(), and hash_mem() is
likewise a wrapper around full_name_hash().
Note that sunrpc code *does* call hash_mem() with a zero length, which
is why the previous patch needed to handle that in full_name_hash().
(Thanks, Bruce, for finding that!)
This also eliminates the only caller of hash_long which asks for
more than 32 bits of output.
The comment about the quality of hashlen_string() and full_name_hash()
is jumping the gun by a few patches; they aren't very impressive now,
but will be improved greatly later in the series.
Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Tested-by: J. Bruce Fields <bfields@redhat.com>
Acked-by: J. Bruce Fields <bfields@redhat.com>
Cc: Jeff Layton <jlayton@poochiereds.net>
Cc: linux-nfs@vger.kernel.org
We'd like to make more use of the highly-optimized dcache hash functions
throughout the kernel, rather than have every subsystem create its own,
and a function that hashes basic null-terminated strings is required
for that.
(The name is to emphasize that it returns both hash and length.)
It's actually useful in the dcache itself, specifically d_alloc_name().
Other uses in the next patch.
full_name_hash() is also tweaked to make it more generally useful:
1) Take a "char *" rather than "unsigned char *" argument, to
be consistent with hash_name().
2) Handle zero-length inputs. If we want more callers, we don't want
to make them worry about corner cases.
Signed-off-by: George Spelvin <linux@sciencehorizons.net>
... so they can be used without the rest of <linux/dcache.h>
The hashlen_* macros will make sense next patch.
Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Pull i2c fix from Wolfram Sang:
"A fix for a regression introduced yesterday.
The regression didn't show up here locally because I did not have
PAGE_POISONING enabled. And buildbots discovered this only after it
hit your tree. Thanks to Dan for the quick response"
* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: dev: use after free in detach
A handful of changes this merge window:
- A few patches to fix probing and configuration of pstore
- A few patches adding Elan touchpad registration on a few devices
- EC changes: a security fix dealing with max message sizes and addition
of compat_ioctl support.
- Keyboard backlight control support
There was also an accidential duplicate registration of trackpads on 'Leon',
which was reverted just recently.
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Merge tag 'chrome-platform' of git://git.kernel.org/pub/scm/linux/kernel/git/olof/chrome-platform
Pull chrome platform updates from Olof Johansson
"A handful of Chrome driver and binding changes this merge window:
- a few patches to fix probing and configuration of pstore
- a few patches adding Elan touchpad registration on a few devices
- EC changes: a security fix dealing with max message sizes and
addition of compat_ioctl support.
- keyboard backlight control support
There was also an accidential duplicate registration of trackpads on
'Leon', which was reverted just recently"
* tag 'chrome-platform' of git://git.kernel.org/pub/scm/linux/kernel/git/olof/chrome-platform:
Revert "platform/chrome: chromeos_laptop: Add Leon Touch"
platform/chrome: chromeos_laptop - Add Elan touchpad for Wolf
platform/chrome: chromeos_laptop - Add elan trackpad option for C720
platform/chrome: cros_ec_dev - Populate compat_ioctl
platform/chrome: cros_ec_lightbar - use name instead of ID to hide lightbar attributes
platform/chrome: cros_ec_dev - Fix security issue
platform/chrome: Add Chrome OS keyboard backlight LEDs support
platform/chrome: use to_platform_device()
platform/chrome: pstore: Move to larger record size.
platform/chrome: pstore: probe for ramoops buffer using acpi
platform/chrome: chromeos_laptop: Add Leon Touch
This is the second update round for 4.7-rc1. Most of changes are
about the pending ASoC updates and fixes, including a few new
drivers. Below are some highlights:
ASoC:
- New drivers for MAX98371 and TAS5720
- SPI support for TLV320AIC32x4, along with the module split
- TDM support for STI Uniperf IPs
- Remaining topology API fixes / updates
HDA:
- A couple of Dell quirks and new Realtek codec support
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Merge tag 'sound-4.7-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull more sound updates from Takashi Iwai:
"This is the second update round for 4.7-rc1. Most of changes are
about the pending ASoC updates and fixes, including a few new drivers.
Below are some highlights:
ASoC:
- New drivers for MAX98371 and TAS5720
- SPI support for TLV320AIC32x4, along with the module split
- TDM support for STI Uniperf IPs
- Remaining topology API fixes / updates
HDA:
- A couple of Dell quirks and new Realtek codec support"
* tag 'sound-4.7-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (63 commits)
ALSA: hda - Fix headset mic detection problem for one Dell machine
spi: spi-ep93xx: Fix the PTR_ERR() argument
ALSA: hda/realtek - Add support for ALC295/ALC3254
ASoC: kirkwood: fix build failure
ALSA: hda - Fix headphone noise on Dell XPS 13 9360
ASoC: ak4642: Enable cache usage to fix crashes on resume
ASoC: twl6040: Disconnect AUX output pads on digital mute
ASoC: tlv320aic32x4: Properly implement the positive and negative pins into the mixers
rcar: src: skip disabled-SRC nodes
ASoC: max98371 Remove duplicate entry in max98371_reg
ASoC: twl6040: Select LPPLL during standby
ASoC: rsnd: don't use prohibited number to PDMACHCRn.SRS
ASoC: simple-card: Add pm callbacks to platform driver
ASoC: pxa: Fix module autoload for platform drivers
ASoC: topology: Fix memory leak in widget creation
ASoC: Add max98371 codec driver
ASoC: rsnd: count .probe/.remove for rsnd_mod_call()
ASoC: topology: Check size mismatch of ABI objects before parsing
ASoC: topology: Check failure to create a widget
ASoC: add support for TAS5720 digital amplifier
...
Pull SCSI target updates from Nicholas Bellinger:
"Here are the outstanding target pending updates for v4.7-rc1.
The highlights this round include:
- Allow external PR/ALUA metadata path be defined at runtime via top
level configfs attribute (Lee)
- Fix target session shutdown bug for ib_srpt multi-channel (hch)
- Make TFO close_session() and shutdown_session() optional (hch)
- Drop se_sess->sess_kref + convert tcm_qla2xxx to internal kref
(hch)
- Add tcm_qla2xxx endpoint attribute for basic FC jammer (Laurence)
- Refactor iscsi-target RX/TX PDU encode/decode into common code
(Varun)
- Extend iscsit_transport with xmit_pdu, release_cmd, get_rx_pdu,
validate_parameters, and get_r2t_ttt for generic ISO offload
(Varun)
- Initial merge of cxgb iscsi-segment offload target driver (Varun)
The bulk of the changes are Chelsio's new driver, along with a number
of iscsi-target common code improvements made by Varun + Co along the
way"
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (29 commits)
iscsi-target: Fix early sk_data_ready LOGIN_FLAGS_READY race
cxgbit: Use type ISCSI_CXGBIT + cxgbit tpg_np attribute
iscsi-target: Convert transport drivers to signal rdma_shutdown
iscsi-target: Make iscsi_tpg_np driver show/store use generic code
tcm_qla2xxx Add SCSI command jammer/discard capability
iscsi-target: graceful disconnect on invalid mapping to iovec
target: need_to_release is always false, remove redundant check and kfree
target: remove sess_kref and ->shutdown_session
iscsi-target: remove usage of ->shutdown_session
tcm_qla2xxx: introduce a private sess_kref
target: make close_session optional
target: make ->shutdown_session optional
target: remove acl_stop
target: consolidate and fix session shutdown
cxgbit: add files for cxgbit.ko
iscsi-target: export symbols
iscsi-target: call complete on conn_logout_comp
iscsi-target: clear tx_thread_active
iscsi-target: add new offload transport type
iscsi-target: use conn_transport->transport_type in text rsp
...
- Dynamic counter infrastructure in the IB drivers
This is a sysfs based code to allow free form access to the hardware
counters RDMA devices might support so drivers don't need to code
this up repeatedly themselves
- SendOnlyFullMember multicast support
- IB router support
- A couple misc fixes
- The big item on the list: hfi1 driver updates, plus moving the hfi1
driver out of staging
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma
Pull more rdma updates from Doug Ledford:
"This is the second group of code for the 4.7 merge window. It looks
large, but only in one sense. I'll get to that in a minute. The list
of changes here breaks down as follows:
- Dynamic counter infrastructure in the IB drivers
This is a sysfs based code to allow free form access to the
hardware counters RDMA devices might support so drivers don't need
to code this up repeatedly themselves
- SendOnlyFullMember multicast support
- IB router support
- A couple misc fixes
- The big item on the list: hfi1 driver updates, plus moving the hfi1
driver out of staging
There was a group of 15 patches in the hfi1 list that I thought I had
in the first pull request but they weren't. So that added to the
length of the hfi1 section here.
As far as these go, everything but the hfi1 is pretty straight
forward.
The hfi1 is, if you recall, the driver that Al had complaints about
how it used the write/writev interfaces in an overloaded fashion. The
write portion of their interface behaved like the write handler in the
IB stack proper and did bi-directional communications. The writev
interface, on the other hand, only accepts SDMA request structures.
The completions for those structures are sent back via an entirely
different event mechanism.
With the security patch, we put security checks on the write
interface, however, we also knew they would be going away soon. Now,
we've converted the write handler in the hfi1 driver to use ioctls
from the IB reserved magic area for its bidirectional communications.
With that change, Intel has addressed all of the items originally on
their TODO when they went into staging (as well as many items added to
the list later).
As such, I moved them out, and since they were the last item in the
staging/rdma directory, and I don't have immediate plans to use the
staging area again, I removed the staging/rdma area.
Because of the move out of staging, as well as a series of 5 patches
in the hfi1 driver that removed code people thought should be done in
a different way and was optional to begin with (a snoop debug
interface, an eeprom driver for an eeprom connected directory to their
hfi1 chip and not via an i2c bus, and a few other things like that),
the line count, especially the removal count, is high"
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma: (56 commits)
staging/rdma: Remove the entire rdma subdirectory of staging
IB/core: Make device counter infrastructure dynamic
IB/hfi1: Fix pio map initialization
IB/hfi1: Correct 8051 link parameter settings
IB/hfi1: Update pkey table properly after link down or FM start
IB/rdamvt: Fix rdmavt s_ack_queue sizing
IB/rdmavt: Max atomic value should be a u8
IB/hfi1: Fix hard lockup due to not using save/restore spin lock
IB/hfi1: Add tracing support for send with invalidate opcode
IB/hfi1, qib: Add ieth to the packet header definitions
IB/hfi1: Move driver out of staging
IB/hfi1: Do not free hfi1 cdev parent structure early
IB/hfi1: Add trace message in user IOCTL handling
IB/hfi1: Remove write(), use ioctl() for user cmds
IB/hfi1: Add ioctl() interface for user commands
IB/hfi1: Remove unused user command
IB/hfi1: Remove snoop/diag interface
IB/hfi1: Remove EPROM functionality from data device
IB/hfi1: Remove UI char device
IB/hfi1: Remove multiple device cdev
...
This reverts commit bff3c624dc.
Board "Leon" is otherwise known as "Toshiba CB35" and we already have
the entry that supports that board as of this commit :
963cb6f platform/chrome: chromeos_laptop - Add Toshiba CB35 Touch
Remove this duplicate.
Signed-off-by: Benson Leung <bleung@chromium.org>
Signed-off-by: Olof Johansson <olof@lixom.net>
The call to put_i2c_dev() frees "i2c_dev" so there is a use after
free when we call cdev_del(&i2c_dev->cdev).
Fixes: d6760b14d4 ('i2c: dev: switch from register_chrdev to cdev API')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
MicroMIPS kernels may be expected to run on microMIPS only cores which
don't support the normal MIPS instruction set, so be sure to pass the
-mmicromips flag through to the VDSO cflags.
Fixes: ebb5e78cc6 ("MIPS: Initial implementation of a VDSO")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 4.4.x-
Patchwork: https://patchwork.linux-mips.org/patch/13349/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
In microMIPS kernels, handle_signal() sets the isa16 mode bit in the
vdso address so that the sigreturn trampolines (which are offset from
the VDSO) get executed as microMIPS.
However commit ebb5e78cc6 ("MIPS: Initial implementation of a VDSO")
changed the offsets to come from the VDSO image, which already have the
isa16 mode bit set correctly since they're extracted from the VDSO
shared library symbol table.
Drop the isa16 mode bit handling from handle_signal() to fix sigreturn
for cores which support both microMIPS and normal MIPS. This doesn't fix
microMIPS only cores, since the VDSO is still built for normal MIPS, but
thats a separate problem.
Fixes: ebb5e78cc6 ("MIPS: Initial implementation of a VDSO")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 4.4.x-
Patchwork: https://patchwork.linux-mips.org/patch/13348/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Here is the quote from [1]:
The unit-address must match the first address specified
in the reg property of the node. If the node has no reg property,
the @ and unit-address must be omitted and the node-name alone
differentiates the node from other nodes at the same level
This patch adjusts MIPS dts-files and devicetree binding
documentation in accordance with [1].
[1] Power.org(tm) Standard for Embedded Power Architecture(tm)
Platform Requirements (ePAPR). Version 1.1 – 08 April 2011.
Chapter 2.2.1.1 Node Name Requirements
Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.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: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13345/
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Avoid an aliasing issue causing a build error in VDSO:
In file included from include/linux/srcu.h:34:0,
from include/linux/notifier.h:15,
from ./arch/mips/include/asm/uprobes.h:9,
from include/linux/uprobes.h:61,
from include/linux/mm_types.h:13,
from ./arch/mips/include/asm/vdso.h:14,
from arch/mips/vdso/vdso.h:27,
from arch/mips/vdso/gettimeofday.c:11:
include/linux/workqueue.h: In function 'work_static':
include/linux/workqueue.h:186:2: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing]
return *work_data_bits(work) & WORK_STRUCT_STATIC;
^
cc1: all warnings being treated as errors
make[2]: *** [arch/mips/vdso/gettimeofday.o] Error 1
with a CONFIG_DEBUG_OBJECTS_WORK configuration and GCC 5.2.0. Include
`-fno-strict-aliasing' along with compiler options used, as required for
kernel code, fixing a problem present since the introduction of VDSO
with commit ebb5e78cc6 ("MIPS: Initial implementation of a VDSO").
Thanks to Tejun for diagnosing this properly!
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Fixes: ebb5e78cc6 ("MIPS: Initial implementation of a VDSO")
Cc: Tejun Heo <tj@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org # v4.3+
Patchwork: https://patchwork.linux-mips.org/patch/13357/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Allow KASLR to be selected on Pistachio based systems. Tested on a
Creator Ci40.
Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Jonas Gorski <jogo@openwrt.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13356/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
On certain MIPS32 devices, the ftrace tracer "function_graph" uses
__lshrdi3() during the capturing of trace data. ftrace then attempts to
trace __lshrdi3() which leads to infinite recursion and a stack overflow.
Fix this by marking __lshrdi3() as notrace. Mark the other compiler
intrinsics as notrace in case the compiler decides to use them in the
ftrace path.
Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com>
Cc: <linux-mips@linux-mips.org>
Cc: <linux-kernel@vger.kernel.org>
Cc: <stable@vger.kernel.org> # 4.2.x-
Patchwork: https://patchwork.linux-mips.org/patch/13354/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The Hardware page Table Walker (HTW) is being misconfigured on 64-bit
kernels. The PWSize.PS (pointer size) bit determines whether pointers
within directories are loaded as 32-bit or 64-bit addresses, but was
never being set to 1 for 64-bit kernels where the unsigned long in pgd_t
is 64-bits wide.
This actually reduces rather than improves performance when the HTW is
enabled on P6600 since the HTW is initiated lots, but walks are all
aborted due I think to bad intermediate pointers.
Since we were already taking the width of the PTEs into account by
setting PWSize.PTEW, which is the left shift applied to the page table
index *in addition to* the native pointer size, we also need to reduce
PTEW by 1 when PS=1. This is done by calculating PTEW based on the
relative size of pte_t compared to pgd_t.
Finally in order for the HTW to be used when PS=1, the appropriate
XK/XS/XU bits corresponding to the different 64-bit segments need to be
set in PWCtl. We enable only XU for now to enable walking for XUSeg.
Supporting walking for XKSeg would be a bit more involved so is left for
a future patch. It would either require the use of a per-CPU top level
base directory if supported by the HTW (a bit like pgd_current but with
a second entry pointing at swapper_pg_dir), or the HTW would prepend bit
63 of the address to the global directory index which doesn't really
match how we split user and kernel page directories.
Fixes: cab25bc753 ("MIPS: Extend hardware table walking support to MIPS64")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13364/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add field definitions for some of the 64-bit specific Hardware page
Table Walker (HTW) register fields in PWSize and PWCtl, in preparation
for fixing the 64-bit HTW configuration.
Also print these fields out along with the others in print_htw_config().
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13363/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Simplify the DSP instruction wrapper macros which use explicit encodings
for microMIPS and normal MIPS by using the new encoding macros and
removing duplication.
To me this makes it easier to read since it is much shorter, but it also
ensures .insn is used, preventing objdump disassembling the microMIPS
code as normal MIPS.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13314/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Hardcoded MIPS instruction encodings are provided for tlbinvf, mfhc0 &
mthc0 instructions, but microMIPS encodings are missing. I doubt any
microMIPS cores exist at present which support these instructions, but
the microMIPS encodings exist, and microMIPS cores may support them in
the future. Add the missing microMIPS encodings using the new macros.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13313/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
When the toolchain doesn't support MSA we encode MSA instructions
explicitly in assembly. Unfortunately we use .word for both MIPS and
microMIPS encodings which is wrong, since 32-bit microMIPS instructions
are made up from a pair of halfwords.
- The most significant halfword always comes first, so for little endian
builds the halves will be emitted in the wrong order.
- 32-bit alignment isn't guaranteed, so the assembler may insert a
16-bit nop instruction to pad the instruction stream to a 32-bit
boundary.
Use the new instruction encoding macros to encode microMIPS MSA
instructions correctly.
Fixes: d96cc3d1ec ("MIPS: Add microMIPS MSA support.")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <Paul.Burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13312/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Toolchains may be used which support microMIPS but not VZ instructions
(i.e. binutis 2.22 & 2.23), so extend the explicitly encoded versions of
the guest COP0 register & guest TLB access macros to support microMIPS
encodings too, using the new macros.
This prevents non-microMIPS instructions being executed in microMIPS
mode during CPU probe on cores supporting VZ (e.g. M5150), which cause
reserved instruction exceptions early during boot.
Fixes: bad50d7925 ("MIPS: Fix VZ probe gas errors with binutils <2.24")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13311/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
To allow simplification of macros which use inline assembly to
explicitly encode instructions, add a few simple abstractions to
mipsregs.h which expand to specific microMIPS or normal MIPS encodings
depending on what type of kernel is being built:
_ASM_INSN_IF_MIPS(_enc) : Emit a 32bit MIPS instruction if microMIPS is
not enabled.
_ASM_INSN32_IF_MM(_enc) : Emit a 32bit microMIPS instruction if enabled.
_ASM_INSN16_IF_MM(_enc) : Emit a 16bit microMIPS instruction if enabled.
The macros can be used one after another since the MIPS / microMIPS
macros are mutually exclusive, for example:
__asm__ __volatile__(
".set push\n\t"
".set noat\n\t"
"# mfgc0 $1, $%1, %2\n\t"
_ASM_INSN_IF_MIPS(0x40610000 | %1 << 11 | %2)
_ASM_INSN32_IF_MM(0x002004fc | %1 << 16 | %2 << 11)
"move %0, $1\n\t"
".set pop"
: "=r" (__res)
: "i" (source), "i" (sel));
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13310/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
As noticed by Sergei in the discussion of Andrea Gelmini's patch series.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Reported-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
