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Add this missing compatibility string to the Reset Controller
compatible string chip list.
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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The work which is scheduled on a POR boot is potentially left
pending or running until after the device module is removed,
which could result in a use-after-free.
Fix by registering a cancel/sync callback, which gets executed as
part of standard resource unwinding.
This issue was detected with the help of Coccinelle.
Signed-off-by: Sven Van Asbroeck <TheSven73@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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Add a field for "voltage_max_design_uv" to present fully charged
battery voltage.
Signed-off-by: Artur Rojek <contact@artur-rojek.eu>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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Add documentation for the "voltage-max-design-microvolt" property.
Signed-off-by: Artur Rojek <contact@artur-rojek.eu>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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The flags were just read by bq27xxx_battery_update(),
no need to read them again.
Signed-off-by: Arthur Demchenkov <spinal.by@gmail.com>
Reviewed-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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In remove(), use cancel_delayed_work_sync() to cancel the
delayed work. Otherwise there's a chance that this work
will continue to run until after the device has been removed.
While we're here, fix the deallocation order in remove(),
to correspond to the inverse of the probe() allocation
order. This guarantees that any remaining work can run
to completion with all driver structures still intact.
This issue was detected with the help of Coccinelle.
Signed-off-by: Sven Van Asbroeck <TheSven73@gmail.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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Use firmware-provided limits for POWER_SUPPLY_*_MAX properties instead
of chip max values. This will reflect the battery limits as those are
the important ones.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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We found sometimes we can not get the saving capacity to initialize the
battery capacity, the reason is the user area registers are put on power
always-on region, so we need delay some time to wait until values are
updated successfully.
Moreover we also should clear the USER_AREA_CLEAR register after setting
the USER_AREA_SET register, otherwise we can not save the values in the
USER_AREA_SET register.
Signed-off-by: Yuanjiang Yu <yuanjiang.yu@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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We should multiply the calibrated current data (cur_1000ma_adc) when
converting current capacity (mAh) to coulomb counter, which can get
an accurate coulomb counter from the fuel gauge controller.
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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Add POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE property to get charge
voltage sampling by ADC controller, which is used to validate if the
charge voltage is in normal range or not in charger manager.
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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Add one IIO channel named "charge_vol" to read the charge voltage for
the SC27XX fuel gauge controller.
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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To comply with tests we need to support more power supply properties:
POWER_SUPPLY_PROP_VOLTAGE_NOW
POWER_SUPPLY_PROP_TEMP
POWER_SUPPLY_PROP_CHARGE_COUNTER
POWER_SUPPLY_PROP_CURRENT_NOW
POWER_SUPPLY_PROP_CURRENT_AVG
POWER_SUPPLY_PROP_CHARGE_FULL
POWER_SUPPLY_PROP_CYCLE_COUNT
POWER_SUPPLY_PROP_VOLTAGE_MAX
POWER_SUPPLY_PROP_CURRENT_MAX
Signed-off-by: Roman Kiryanov <rkir@google.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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Fix few trivial language typos.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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The driver doesn't generate uevents on charger connect/disconnect.
This leads to UPower not detecting when AC is on or off... and that is
bad.
Reported by Arthur D. on github (
https://github.com/maemo-leste/bugtracker/issues/206 ), thanks to
Merlijn Wajer for suggesting a fix.
Cc: stable@kernel.org
Signed-off-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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We include of.h twice. It's unnecessary,so
just remove them.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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If twl4030_bci_read() fails, the read data in "s" is incorrect,
which is however used in the following execution. The fix checks
the return value of twl4030_bci_read() and returns an error code
upstream upon the failure of twl4030_bci_read().
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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Tabs are preferred.
Signed-off-by: Roman Kiryanov <rkir@google.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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Align two values as other values below.
Signed-off-by: Roman Kiryanov <rkir@google.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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The battery_data static variable was not used.
Signed-off-by: Roman Kiryanov <rkir@google.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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There was a line longer than 80 characters.
Signed-off-by: Roman Kiryanov <rkir@google.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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There was a checkpatch complain:
"Missing or malformed SPDX-License-Identifier tag".
Signed-off-by: Roman Kiryanov <rkir@google.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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This migrates isp1704 driver from old GPIO API to new descriptor
based GPIO API and drops useless platform data as a side-effect.
Migration is simple, since all mainline users are DT based and
DT API does not change. Out of tree users of the platform data
need to migrate to gpiod_lookup_table as described here:
Documentation/driver-api/gpio/board.rst
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
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The semantics of what "in core" means for the mincore() system call are
somewhat unclear, but Linux has always (since 2.3.52, which is when
mincore() was initially done) treated it as "page is available in page
cache" rather than "page is mapped in the mapping".
The problem with that traditional semantic is that it exposes a lot of
system cache state that it really probably shouldn't, and that users
shouldn't really even care about.
So let's try to avoid that information leak by simply changing the
semantics to be that mincore() counts actual mapped pages, not pages
that might be cheaply mapped if they were faulted (note the "might be"
part of the old semantics: being in the cache doesn't actually guarantee
that you can access them without IO anyway, since things like network
filesystems may have to revalidate the cache before use).
In many ways the old semantics were somewhat insane even aside from the
information leak issue. From the very beginning (and that beginning is
a long time ago: 2.3.52 was released in March 2000, I think), the code
had a comment saying
Later we can get more picky about what "in core" means precisely.
and this is that "later". Admittedly it is much later than is really
comfortable.
NOTE! This is a real semantic change, and it is for example known to
change the output of "fincore", since that program literally does a
mmmap without populating it, and then doing "mincore()" on that mapping
that doesn't actually have any pages in it.
I'm hoping that nobody actually has any workflow that cares, and the
info leak is real.
We may have to do something different if it turns out that people have
valid reasons to want the old semantics, and if we can limit the
information leak sanely.
Cc: Kevin Easton <kevin@guarana.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Masatake YAMATO <yamato@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Commit 594cc251fdd0 ("make 'user_access_begin()' do 'access_ok()'")
broke both alpha and SH booting in qemu, as noticed by Guenter Roeck.
It turns out that the bug wasn't actually in that commit itself (which
would have been surprising: it was mostly a no-op), but in how the
addition of access_ok() to the strncpy_from_user() and strnlen_user()
functions now triggered the case where those functions would test the
access of the very last byte of the user address space.
The string functions actually did that user range test before too, but
they did it manually by just comparing against user_addr_max(). But
with user_access_begin() doing the check (using "access_ok()"), it now
exposed problems in the architecture implementations of that function.
For example, on alpha, the access_ok() helper macro looked like this:
#define __access_ok(addr, size) \
((get_fs().seg & (addr | size | (addr+size))) == 0)
and what it basically tests is of any of the high bits get set (the
USER_DS masking value is 0xfffffc0000000000).
And that's completely wrong for the "addr+size" check. Because it's
off-by-one for the case where we check to the very end of the user
address space, which is exactly what the strn*_user() functions do.
Why? Because "addr+size" will be exactly the size of the address space,
so trying to access the last byte of the user address space will fail
the __access_ok() check, even though it shouldn't. As a result, the
user string accessor functions failed consistently - because they
literally don't know how long the string is going to be, and the max
access is going to be that last byte of the user address space.
Side note: that alpha macro is buggy for another reason too - it re-uses
the arguments twice.
And SH has another version of almost the exact same bug:
#define __addr_ok(addr) \
((unsigned long __force)(addr) < current_thread_info()->addr_limit.seg)
so far so good: yes, a user address must be below the limit. But then:
#define __access_ok(addr, size) \
(__addr_ok((addr) + (size)))
is wrong with the exact same off-by-one case: the case when "addr+size"
is exactly _equal_ to the limit is actually perfectly fine (think "one
byte access at the last address of the user address space")
The SH version is actually seriously buggy in another way: it doesn't
actually check for overflow, even though it did copy the _comment_ that
talks about overflow.
So it turns out that both SH and alpha actually have completely buggy
implementations of access_ok(), but they happened to work in practice
(although the SH overflow one is a serious serious security bug, not
that anybody likely cares about SH security).
This fixes the problems by using a similar macro on both alpha and SH.
It isn't trying to be clever, the end address is based on this logic:
unsigned long __ao_end = __ao_a + __ao_b - !!__ao_b;
which basically says "add start and length, and then subtract one unless
the length was zero". We can't subtract one for a zero length, or we'd
just hit an underflow instead.
For a lot of access_ok() users the length is a constant, so this isn't
actually as expensive as it initially looks.
Reported-and-tested-by: Guenter Roeck <linux@roeck-us.net>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Add support for the Adiantum encryption mode to fscrypt. Adiantum is a
tweakable, length-preserving encryption mode with security provably
reducible to that of XChaCha12 and AES-256, subject to a security bound.
It's also a true wide-block mode, unlike XTS. See the paper
"Adiantum: length-preserving encryption for entry-level processors"
(https://eprint.iacr.org/2018/720.pdf) for more details. Also see
commit 059c2a4d8e16 ("crypto: adiantum - add Adiantum support").
On sufficiently long messages, Adiantum's bottlenecks are XChaCha12 and
the NH hash function. These algorithms are fast even on processors
without dedicated crypto instructions. Adiantum makes it feasible to
enable storage encryption on low-end mobile devices that lack AES
instructions; currently such devices are unencrypted. On ARM Cortex-A7,
on 4096-byte messages Adiantum encryption is about 4 times faster than
AES-256-XTS encryption; decryption is about 5 times faster.
In fscrypt, Adiantum is suitable for encrypting both file contents and
names. With filenames, it fixes a known weakness: when two filenames in
a directory share a common prefix of >= 16 bytes, with CTS-CBC their
encrypted filenames share a common prefix too, leaking information.
Adiantum does not have this problem.
Since Adiantum also accepts long tweaks (IVs), it's also safe to use the
master key directly for Adiantum encryption rather than deriving
per-file keys, provided that the per-file nonce is included in the IVs
and the master key isn't used for any other encryption mode. This
configuration saves memory and improves performance. A new fscrypt
policy flag is added to allow users to opt-in to this configuration.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
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Remove the dot-prefixing since it is just a matter of the
.gitignore file.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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Make simply skips a missing rule when it is marked as .PHONY.
Remove the dummy targets.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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You do not have to use define ... endef for filechk_* rules.
For simple cases, the use of assignment looks cleaner, IMHO.
I updated the usage for scripts/Kbuild.include in case somebody
misunderstands the 'define ... endif' is the requirement.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
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Now that Kbuild automatically creates asm-generic wrappers for missing
mandatory headers, it is redundant to list the same headers in
generic-y and mandatory-y.
Suggested-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
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Some time ago, Sam pointed out a certain degree of overwrap between
generic-y and mandatory-y. (https://lkml.org/lkml/2017/7/10/121)
I tweaked the meaning of mandatory-y a little bit; now it defines the
minimum set of ASM headers that all architectures must have.
If arch does not have specific implementation of a mandatory header,
Kbuild will let it fallback to the asm-generic one by automatically
generating a wrapper. This will allow to drop lots of redundant
generic-y defines.
Previously, "mandatory" was used in the context of UAPI, but I guess
this can be extended to kernel space ASM headers.
Suggested-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
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These comments are leftovers of commit fcc8487d477a ("uapi: export all
headers under uapi directories").
Prior to that commit, exported headers must be explicitly added to
header-y. Now, all headers under the uapi/ directories are exported.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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This commit removes redundant generic-y defines in
arch/riscv/include/asm/Kbuild.
[1] It is redundant to define the same generic-y in both
arch/$(ARCH)/include/asm/Kbuild and
arch/$(ARCH)/include/uapi/asm/Kbuild.
Remove the following generic-y:
errno.h
fcntl.h
ioctl.h
ioctls.h
ipcbuf.h
mman.h
msgbuf.h
param.h
poll.h
posix_types.h
resource.h
sembuf.h
setup.h
shmbuf.h
signal.h
socket.h
sockios.h
stat.h
statfs.h
swab.h
termbits.h
termios.h
types.h
[2] It is redundant to define generic-y when arch-specific
implementation exists in arch/$(ARCH)/include/asm/*.h
Remove the following generic-y:
cacheflush.h
module.h
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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filechk_* rules often consist of multiple 'echo' lines. They must be
surrounded with { } or ( ) to work correctly. Otherwise, only the
string from the last 'echo' would be written into the target.
Let's take care of that in the 'filechk' in scripts/Kbuild.include
to clean up filechk_* rules.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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Since commit 9c2af1c7377a ("kbuild: add .DELETE_ON_ERROR special
target"), the target file is automatically deleted on failure.
The boilerplate code
... || { rm -f $@; false; }
is unneeded.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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Commit 3a2429e1faf4 ("kbuild: change if_changed_rule for multi-line
recipe") and commit 4f0e3a57d6eb ("kbuild: Add support for DT binding
schema checks") came in via different sub-systems.
This is a follow-up cleanup.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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The only/last user of UIMAGE_IN/OUT was removed by commit 4722a3e6b716
("microblaze: fix multiple bugs in arch/microblaze/boot/Makefile").
The input and output should always be $< and $@.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label".
The jump label is controlled by HAVE_JUMP_LABEL, which is defined
like this:
#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
# define HAVE_JUMP_LABEL
#endif
We can improve this by testing 'asm goto' support in Kconfig, then
make JUMP_LABEL depend on CC_HAS_ASM_GOTO.
Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will
match to the real kernel capability.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
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As mentioned in the info pages of gas, the '.align' pseudo op's
interpretation of the alignment value is architecture specific.
It might either be a byte value or taken to the power of two.
On ARM it's actually the latter which leads to unnecessary large
alignments of 16 bytes for 32 bit builds or 256 bytes for 64 bit
builds.
Fix this by switching to '.balign' instead which is consistent
across all architectures.
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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Coccinelle doesn't always have access to the values of named
(#define) constants, and they may likely often be bound to true
and false values anyway, resulting in false positives. So stop
warning about them.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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Avoid reporting on the use of an iterator index variable when
the variable is redeclared.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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This has never been used.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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This commit removes redundant generic-y defines in
arch/nds32/include/asm/Kbuild.
[1] It is redundant to define the same generic-y in both
arch/$(ARCH)/include/asm/Kbuild and
arch/$(ARCH)/include/uapi/asm/Kbuild.
Remove the following generic-y:
bitsperlong.h
bpf_perf_event.h
errno.h
fcntl.h
ioctl.h
ioctls.h
mman.h
shmbuf.h
stat.h
[2] It is redundant to define generic-y when arch-specific
implementation exists in arch/$(ARCH)/include/asm/*.h
Remove the following generic-y:
ftrace.h
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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kernel/dma/Kconfig globally defines HAS_DMA as follows:
config HAS_DMA
bool
depends on !NO_DMA
default y
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
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Fixes build break on most ARM/ARM64 defconfigs:
lib/genalloc.c: In function 'gen_pool_add_virt':
lib/genalloc.c:190:10: error: implicit declaration of function 'vzalloc_node'; did you mean 'kzalloc_node'?
lib/genalloc.c:190:8: warning: assignment to 'struct gen_pool_chunk *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
lib/genalloc.c: In function 'gen_pool_destroy':
lib/genalloc.c:254:3: error: implicit declaration of function 'vfree'; did you mean 'kfree'?
Fixes: 6862d2fc8185 ('lib/genalloc.c: use vzalloc_node() to allocate the bitmap')
Cc: Huang Shijie <sjhuang@iluvatar.ai>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexey Skidanov <alexey.skidanov@intel.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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We need to return a dma_addr_t even if we don't have a kernel mapping.
Do so by consolidating the phys_to_dma call in a single place and jump
to it from all the branches that return successfully.
Fixes: bfd56cd60521 ("dma-mapping: support highmem in the generic remap allocator")
Reported-by: Liviu Dudau <liviu@dudau.co.uk
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Liviu Dudau <liviu@dudau.co.uk>
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In many cases we don't have to create a GART mapping at all, which
also means there is nothing to unmap. Fix the range check that was
incorrectly modified when removing the mapping_error method.
Fixes: 9e8aa6b546 ("x86/amd_gart: remove the mapping_error dma_map_ops method")
Reported-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Michal Kubecek <mkubecek@suse.cz>
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Some non-generic ia64 configs don't build swiotlb, and thus should not
pull in the generic non-coherent DMA infrastructure.
Fixes: 68c608345c ("swiotlb: remove dma_mark_clean")
Reported-by: Tony Luck <tony.luck@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This has been broken forever, and nobody ever really noticed because
it's purely a performance issue.
Long long ago, in commit 6175ddf06b61 ("x86: Clean up mem*io functions")
Brian Gerst simplified the memory copies to and from iomem, since on
x86, the instructions to access iomem are exactly the same as the
regular instructions.
That is technically true, and things worked, and nobody said anything.
Besides, back then the regular memcpy was pretty simple and worked fine.
Nobody noticed except for David Laight, that is. David has a testing a
TLP monitor he was writing for an FPGA, and has been occasionally
complaining about how memcpy_toio() writes things one byte at a time.
Which is completely unacceptable from a performance standpoint, even if
it happens to technically work.
The reason it's writing one byte at a time is because while it's
technically true that accesses to iomem are the same as accesses to
regular memory on x86, the _granularity_ (and ordering) of accesses
matter to iomem in ways that they don't matter to regular cached memory.
In particular, when ERMS is set, we default to using "rep movsb" for
larger memory copies. That is indeed perfectly fine for real memory,
since the whole point is that the CPU is going to do cacheline
optimizations and executes the memory copy efficiently for cached
memory.
With iomem? Not so much. With iomem, "rep movsb" will indeed work, but
it will copy things one byte at a time. Slowly and ponderously.
Now, originally, back in 2010 when commit 6175ddf06b61 was done, we
didn't use ERMS, and this was much less noticeable.
Our normal memcpy() was simpler in other ways too.
Because in fact, it's not just about using the string instructions. Our
memcpy() these days does things like "read and write overlapping values"
to handle the last bytes of the copy. Again, for normal memory,
overlapping accesses isn't an issue. For iomem? It can be.
So this re-introduces the specialized memcpy_toio(), memcpy_fromio() and
memset_io() functions. It doesn't particularly optimize them, but it
tries to at least not be horrid, or do overlapping accesses. In fact,
this uses the existing __inline_memcpy() function that we still had
lying around that uses our very traditional "rep movsl" loop followed by
movsw/movsb for the final bytes.
Somebody may decide to try to improve on it, but if we've gone almost a
decade with only one person really ever noticing and complaining, maybe
it's not worth worrying about further, once it's not _completely_ broken?
Reported-by: David Laight <David.Laight@aculab.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Nicolas Ferre
Sven Van Asbroeck
Artur Rojek
Arthur Demchenkov
Michał Mirosław
Yuanjiang Yu
Baolin Wang
Roman Kiryanov
Krzysztof Kozlowski
Pavel Machek
Yangtao Li
Kangjie Lu
Sebastian Reichel
Linus Torvalds
Eric Biggers
Masahiro Yamada
Mathias Krause
Julia Lawall
Olof Johansson
Christoph Hellwig