Export the irq_chip_set_wake_parent symbol so that drivers with
hierarchical IRQ chips can be built as a module.
Signed-off-by: Brian Masney <masneyb@onstation.org>
Reported-by: Mark Brown <broonie@kernel.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

The checker complains during build

gpiolib-acpi.c:45: warning: Function parameter or member 'irq_requested' not described in 'acpi_gpio_event'

because the typo in the field description.

Fix the name to have documentation up-to-date.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Some TQ-Systems ComExpress modules contain an IO controller with 8
GPIO lines.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Add missing '*' char to the start of the comment lines.
Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Now that spmi-gpio is a proper hierarchical IRQ chip, and all in-tree
users of device tree have been updated, we can now drop the hack that
was introduced to disassociate the old Linux virq if a hwirq mapping
already exists. That patch was introduced to not break git bisect for
any existing boards.

Driver was tested using gpio-keys and iadc/vadc on the LG Nexus 5
(hammerhead) phone.
Signed-off-by: Brian Masney <masneyb@onstation.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

qpnpint_irq_domain_map did not validate the IRQ type and this can cause
IRQs to not work as expected if an unsupported type (such as
IRQ_TYPE_NONE) is passed in. Now that spmi-gpio is a hierarchical IRQ
controller, and all device tree bindings have been updated, add
additional validation to the type field.
Signed-off-by: Brian Masney <masneyb@onstation.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Add interrupt controller properties now that spmi-gpio is a proper
hierarchical IRQ chip. The interrupts property is no longer needed so
remove it.

This change was not tested on any hardware but the same change was
tested on qcom-pm8941.dtsi using a LG Nexus 5 (hammerhead) phone with
no issues.
Signed-off-by: Brian Masney <masneyb@onstation.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Add interrupt controller properties now that spmi-gpio is a proper
hierarchical IRQ chip. The interrupts property is no longer needed so
remove it.

This change was not tested on any hardware but the same change was
tested on qcom-pm8941.dtsi using a LG Nexus 5 (hammerhead) phone with
no issues.
Signed-off-by: Brian Masney <masneyb@onstation.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Add interrupt controller properties now that spmi-gpio is a proper
hierarchical IRQ chip. The interrupts property is no longer needed so
remove it.

This change was not tested on any hardware but the same change was
tested on qcom-pm8941.dtsi using a LG Nexus 5 (hammerhead) phone with
no issues.
Signed-off-by: Brian Masney <masneyb@onstation.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Add interrupt controller properties now that spmi-gpio is a proper
hierarchical IRQ chip. The interrupts property is no longer needed so
remove it.

This change was not tested on any hardware but the same change was
tested on qcom-pm8941.dtsi using a LG Nexus 5 (hammerhead) phone with
no issues.
Signed-off-by: Brian Masney <masneyb@onstation.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Add interrupt controller properties now that spmi-gpio is a proper
hierarchical IRQ chip. The interrupts property is no longer needed so
remove it.

This change was not tested on any hardware but the same change was
tested on qcom-pm8941.dtsi using a LG Nexus 5 (hammerhead) phone with
no issues.
Signed-off-by: Brian Masney <masneyb@onstation.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Add interrupt controller properties now that spmi-gpio is a proper
hierarchical IRQ chip. The interrupts property is no longer needed so
remove it. Code was tested on the LG Nexus 5 (hammerhead) phone.
Signed-off-by: Brian Masney <masneyb@onstation.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

spmi-gpio did not have any irqchip support so consumers of this in
device tree would need to call gpio[d]_to_irq() in order to get the
proper IRQ on the underlying PMIC. IRQ chips in device tree should
be usable from the start without the consumer having to make an
additional call to get the proper IRQ on the parent. This patch adds
hierarchical IRQ chip support to the spmi-gpio code to correct this
issue.

Driver was tested using the volume buttons (via gpio-keys) on the LG
Nexus 5 (hammerhead) phone with the following two configurations.

volume-up {
        interrupts-extended = <&pm8941_gpios 2 IRQ_TYPE_EDGE_BOTH>;
        ...
};

volume-up {
        gpios = <&pm8941_gpios 2 GPIO_ACTIVE_LOW>;
        ...
};

Both configurations now show that spmi-gpio is the IRQ domain and that
the IRQ is setup in a hierarchy.

$ grep volume_up /proc/interrupts
 72:          6          0  spmi-gpio   1 Edge      volume_up

$ cat /sys/kernel/debug/irq/irqs/72
handler:  handle_edge_irq
device:   (null)
status:   0x00000403
            _IRQ_NOPROBE
istate:   0x00000000
ddepth:   0
wdepth:   0
dstate:   0x02400203
            IRQ_TYPE_EDGE_RISING
            IRQ_TYPE_EDGE_FALLING
            IRQD_ACTIVATED
            IRQD_IRQ_STARTED
node:     0
affinity: 0-3
effectiv:
domain:  :soc:spmi@fc4cf000:pm8941@0:gpios@c000
 hwirq:   0x1
 chip:    spmi-gpio
  flags:   0x4
             IRQCHIP_MASK_ON_SUSPEND
 parent:
    domain:  :soc:spmi@fc4cf000
     hwirq:   0xc100057
     chip:    pmic_arb
      flags:   0x4
                 IRQCHIP_MASK_ON_SUSPEND
Signed-off-by: Brian Masney <masneyb@onstation.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Check to see if the hwirq is already associated with another virq on
this IRQ domain. If so, then disassociate it before associating the
hwirq with the new virq.

This is a temporary hack that is needed in order to not break git
bisect for existing boards. The next patch in this series converts
spmi-gpio to be a hierarchical IRQ chip, then there are several patches
to update all of the device tree files, and finally this patch will be
reverted within the same patch series.

IRQs for spmi-gpio are all initially setup without an IRQ hierarchy
on pmic-arb when mfd/qcom-spmi-pmic.c is probed (via the
devm_of_platform_populate call) due to the interrupts property in
device tree. Once spmi-gpio is converted to be a hierarchical IRQ chip
in the next patch, existing users of gpio[d]_to_irq() will call
pmic_gpio_to_irq(), and that will use the new IRQ chip code in
spmi-gpio that sets up the IRQ in an IRQ hierarchy. The hwirq is now
associated with two Linux virqs and interrupts will not work as
expected. This patch corrects that issue.

Driver was tested using gpio-keys and iadc/vadc on the LG Nexus 5
(hammerhead) phone.
Signed-off-by: Brian Masney <masneyb@onstation.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

This adds the two new functions gpiochip_irq_domain_activate and
gpiochip_irq_domain_deactivate that can be used as the activate and
deactivate functions in the struct irq_domain_ops. This is for
situations where only gpiochip_{lock,unlock}_as_irq needs to be called.
SPMI and SSBI GPIO are two users that will initially use these
functions.
Signed-off-by: Brian Masney <masneyb@onstation.org>
Suggested-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Convert the spmi-pmic-arb IRQ code to use the version 2 IRQ interface
in order to support hierarchical IRQ chips. This is necessary so that
spmi-gpio can be setup as a hierarchical IRQ chip with pmic-arb as the
parent. IRQ chips in device tree should be usable from the start without
the consumer having to make an additional call to gpio[d]_to_irq() to
get the proper IRQ on the parent.

The old qpnpint_irq_domain_map function would hardcode the handler as
handle_level_irq, however qpnpint_irq_set_type would later override the
handler. Properly set the handler when the IRQ is mapped. This new code
doesn't return an error for IRQ_TYPE_NONE and preserves the existing
behavior of using handle_level_irq since there are some broken device
tree bindings that need to be corrected first.

Driver was tested on a LG Nexus 5 (hammerhead) phone.
Signed-off-by: Brian Masney <masneyb@onstation.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Basic implementation of driver is used to support Fintek
F81804 & F81966 gpios with custom register set.
Signed-off-by: Steffen Kothe <steffen.kothe.gc1993@googlemail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

R-Car GPIO controller provides two interfaces to set GPIO line output
signal state, and for a particular GPIO line the selected interface is
determined by OUTDTSEL bit value.

At the moment the driver supports only one of two interfaces, namely
OUTDT General Output Register is used to control the output signal.

While this selection is the default one on reset, it is not explicitly
configured on probe, thus it might be possible that kernel and userspace
consumers of a GPIO won't be able to set the wanted GPIO output signal.

Below is a simple test case to reproduce the described problem and
verify this fix in the kernel on H3 ULCB by setting non-default OUTDTSEL
configuration from a bootloader:

  u-boot    > mw.l 0xe6055440 0x3000 1
  ...
  userspace > echo default-on > /sys/devices/platform/leds/leds/led5/trigger
  userspace > echo default-on > /sys/devices/platform/leds/leds/led6/trigger
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Remove linux/gpio/machine.h which is included more than once.
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Like the Spreadtrum EIC driver[1], this driver needs to emulate edge
triggered interrupts to support the generic gpio-keys driver.

[1]: https://www.spinics.net/lists/kernel/msg2764576.htmlSigned-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

This patch implements level-triggered IRQs in the Hollywood GPIO driver.
Edge triggered interrupts are not supported in this GPIO controller, so
I moved their emulation into a separate patch.
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

When a system has two PCA953x GPIO expanders, the kernel complains with:

gpio gpiochip2: (0-0021): detected irqchip that is shared with multiple gpiochips: please fix the driver.

Indeed, there is a single instance of "struct irq_chip" that gets
re-used for both PCA953x instance. This commit moves the "struct
irq_chip" to be part of the "struct pca953x_chip", so that we have one
"struct irq_chip" per PCA953X instance.

As part of this, the name of the irq_chip is also made different on a
per-instance basis, now using the dev_name() of the I2C device. This
changes what is visible in /proc/interrupts.

Before:

 47:          0          0   pca953x  10 Edge      e0100000.sdhci cd
 48:          0          0   pca953x   6 Edge      e0101000.sdhci cd

After:

 47:          0          0    0-0020  10 Edge      e0100000.sdhci cd
 48:          2          0    0-0020   6 Edge      e0101000.sdhci cd
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

The current design of pca953x_irq_setup() is:

 if (all conditions to support IRQ are met) {
   lots of code to support IRQs, which goes to a serious indentation
   level.
 }

 return 0;

It makes more sense to handle this like this:

 if (!all conditions to support IRQ are met)
   return 0;

 handle IRQ support

This commit does just this change, reducing by one tab the indentation
level of the IRQ setup code. Thanks to this reduced indentation level,
we are less restricted by the 80-column limit, and we can have more
function arguments on the same line.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

The probing of this driver calls platform_irq_count, which will
setup all of the IRQs that are configured in device tree. In
preparation for converting this driver to be a hierarchical IRQ
chip, hardcode the IRQ count based on the hardware type so that all
the IRQs are not configured immediately and are configured on an
as-needed basis later in the boot process. This change will also
allow for the removal of the interrupts property later in this
patch series once the hierarchical IRQ chip support is in.

This patch also removes the generic qcom,spmi-gpio OF match since we
don't know the number of pins. All of the existing upstream bindings
already include the more-specific binding.

The pm8941 code was tested on a LG Nexus 5 (hammerhead) phone.
Signed-off-by: Brian Masney <masneyb@onstation.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Add support for qcom,pm8005-gpio, qcom,pm8998-gpio, and
qcom,pmi8998-gpio. These three variants are already in use in some
arm64 dtsi files. Those boards work since the generic binding
qcom,spmi-gpio is also specified.
Signed-off-by: Brian Masney <masneyb@onstation.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Add support for the PMI8998 GPIO variant to the Qualcomm PMIC GPIO
binding document.
Signed-off-by: Brian Masney <masneyb@onstation.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

The Spreadtrum PMIC interrupt controller has no registers to set irq
trigger type, since it is always high level trigger. That means the
PMIC EIC controller as a child device of PMIC INTC does not need to
set the trigger type, so remove it.
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Set proper output level base on the argument of direction_output.
Also remove sama5d2_piobu_set_direction() as there is only one caller
now.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

__acpi_gpio_update_gpiod_flags purpose is to make the gpiod_flags used
when requesting a GPIO match the restrictions from the ACPI resource,
as stored in acpi_gpio_info.flags.

But acpi_gpio_info.flags only contains direction info, and the
requester may have passed in special non-direction flags like
GPIOD_FLAGS_BIT_NONEXCLUSIVE, which we currently clobber.

This commit modifies __acpi_gpio_update_gpiod_flags to preserve these
special flags, so that a requested of an ACPI GPIO can e.g. pass
GPIOD_FLAGS_BIT_NONEXCLUSIV and have it work as intended.
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

struct gpio_chip documentation recommends to always implement this
callback function.

A more concrete motivation is to be able (in combination with
GPIOD_ASIS) to detect whether the bootloader has changed the state of a
GPIO signal.
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Pull more Kbuild updates from Masahiro Yamada:

 - improve boolinit.cocci and use_after_iter.cocci semantic patches

 - fix alignment for kallsyms

 - move 'asm goto' compiler test to Kconfig and clean up jump_label
   CONFIG option

 - generate asm-generic wrappers automatically if arch does not
   implement mandatory UAPI headers

 - remove redundant generic-y defines

 - misc cleanups

* tag 'kbuild-v4.21-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kconfig: rename generated .*conf-cfg to *conf-cfg
  kbuild: remove unnecessary stubs for archheader and archscripts
  kbuild: use assignment instead of define ... endef for filechk_* rules
  arch: remove redundant UAPI generic-y defines
  kbuild: generate asm-generic wrappers if mandatory headers are missing
  arch: remove stale comments "UAPI Header export list"
  riscv: remove redundant kernel-space generic-y
  kbuild: change filechk to surround the given command with { }
  kbuild: remove redundant target cleaning on failure
  kbuild: clean up rule_dtc_dt_yaml
  kbuild: remove UIMAGE_IN and UIMAGE_OUT
  jump_label: move 'asm goto' support test to Kconfig
  kallsyms: lower alignment on ARM
  scripts: coccinelle: boolinit: drop warnings on named constants
  scripts: coccinelle: check for redeclaration
  kconfig: remove unused "file" field of yylval union
  nds32: remove redundant kernel-space generic-y
  nios2: remove unneeded HAS_DMA define

Pull perf tooling updates form Ingo Molnar:
 "A final batch of perf tooling changes: mostly fixes and small
  improvements"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (29 commits)
  perf session: Add comment for perf_session__register_idle_thread()
  perf thread-stack: Fix thread stack processing for the idle task
  perf thread-stack: Allocate an array of thread stacks
  perf thread-stack: Factor out thread_stack__init()
  perf thread-stack: Allow for a thread stack array
  perf thread-stack: Avoid direct reference to the thread's stack
  perf thread-stack: Tidy thread_stack__bottom() usage
  perf thread-stack: Simplify some code in thread_stack__process()
  tools gpio: Allow overriding CFLAGS
  tools power turbostat: Override CFLAGS assignments and add LDFLAGS to build command
  tools thermal tmon: Allow overriding CFLAGS assignments
  tools power x86_energy_perf_policy: Override CFLAGS assignments and add LDFLAGS to build command
  perf c2c: Increase the HITM ratio limit for displayed cachelines
  perf c2c: Change the default coalesce setup
  perf trace beauty ioctl: Beautify USBDEVFS_ commands
  perf trace beauty: Export function to get the files for a thread
  perf trace: Wire up ioctl's USBDEBFS_ cmd table generator
  perf beauty ioctl: Add generator for USBDEVFS_ ioctl commands
  tools headers uapi: Grab a copy of usbdevice_fs.h
  perf trace: Store the major number for a file when storing its pathname
  ...

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>

Commit 594cc251 ("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>

Pull fscrypt updates from Ted Ts'o:
 "Add Adiantum support for fscrypt"

* tag 'fscrypt_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt:
  fscrypt: add Adiantum support

Pull ext4 bug fixes from Ted Ts'o:
 "Fix a number of ext4 bugs"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix special inode number checks in __ext4_iget()
  ext4: track writeback errors using the generic tracking infrastructure
  ext4: use ext4_write_inode() when fsyncing w/o a journal
  ext4: avoid kernel warning when writing the superblock to a dead device
  ext4: fix a potential fiemap/page fault deadlock w/ inline_data
  ext4: make sure enough credits are reserved for dioread_nolock writes

Pull dma-mapping fixes from Christoph Hellwig:
 "Fix various regressions introduced in this cycles:

   - fix dma-debug tracking for the map_page / map_single
     consolidatation

   - properly stub out DMA mapping symbols for !HAS_DMA builds to avoid
     link failures

   - fix AMD Gart direct mappings

   - setup the dma address for no kernel mappings using the remap
     allocator"

* tag 'dma-mapping-4.21-1' of git://git.infradead.org/users/hch/dma-mapping:
  dma-direct: fix DMA_ATTR_NO_KERNEL_MAPPING for remapped allocations
  x86/amd_gart: fix unmapping of non-GART mappings
  dma-mapping: remove a few unused exports
  dma-mapping: properly stub out the DMA API for !CONFIG_HAS_DMA
  dma-mapping: remove dmam_{declare,release}_coherent_memory
  dma-mapping: implement dmam_alloc_coherent using dmam_alloc_attrs
  dma-mapping: implement dma_map_single_attrs using dma_map_page_attrs

Merge tag 'tag-chrome-platform-for-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/bleung/chrome-platform

Pull chrome platform updates from Benson Leung:

 - Changes for EC_MKBP_EVENT_SENSOR_FIFO handling.

 - Also, maintainership changes. Olofj out, Enric balletbo in.

* tag 'tag-chrome-platform-for-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/bleung/chrome-platform:
  MAINTAINERS: add maintainers for ChromeOS EC sub-drivers
  MAINTAINERS: platform/chrome: Add Enric as a maintainer
  MAINTAINERS: platform/chrome: remove myself as maintainer
  platform/chrome: don't report EC_MKBP_EVENT_SENSOR_FIFO as wakeup
  platform/chrome: straighten out cros_ec_get_{next,host}_event() error codes