mmc: core: Switch to basic workqueue API for sdio_irq_work

The delay parameter isn't set by any user, therefore simplify the code
and switch to the basic workqueue API w/o delay support. This also
reduces the size of struct mmc_host.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/13d8200a-e2a8-d907-38ce-a16fc5ce14aa@gmail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

sched,mmc: Convert to sched_set_fifo*()

Because SCHED_FIFO is a broken scheduler model (see previous patches)
take away the priority field, the kernel can't possibly make an
informed decision.

In this case, use fifo_low, because it only cares about being above
SCHED_NORMAL. Effectively no change in behaviour.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>

mmc: core: Fix indentation

sdio_single_irq_set() was indented with a mix of tabs and spaces.

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200221163147.608677-1-Jerome.Pouiller@silabs.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

mmc: core: Fixup processing of SDIO IRQs during system suspend/resume

System suspend/resume of SDIO cards, with SDIO IRQs enabled and when using
MMC_CAP2_SDIO_IRQ_NOTHREAD is unfortunate still suffering from a fragile
behaviour. Some problems have been taken care of so far, but more issues
remains.

For example, calling the ->ack_sdio_irq() callback to let host drivers
re-enable the SDIO IRQs is a bad idea, unless the IRQ have been consumed,
which may not be the case during system suspend/resume. This may lead to
that a host driver re-signals the same SDIO IRQ over and over again,
causing a storm of IRQs and gives a ping-pong effect towards the
sdio_irq_work().

Moreover, calling the ->enable_sdio_irq() callback at system resume to
re-enable already enabled SDIO IRQs for the host, causes the runtime PM
count for some host drivers to become in-balanced. This then leads to the
host to remain runtime resumed, no matter if it's needed or not.

To fix these problems, let's check if process_sdio_pending_irqs() actually
consumed the SDIO IRQ, before we continue to ack the IRQ by invoking the
->ack_sdio_irq() callback.

Additionally, there should be no need to re-enable SDIO IRQs as the host
driver already knows if they were enabled at system suspend, thus also
whether it needs to re-enable them at system resume. For this reason, drop
the call to ->enable_sdio_irq() during system resume.

In regards to these changes there is yet another issue, which is when there
is an SDIO IRQ being signaled by the host driver, but after the SDIO card
has been system suspended. Currently these IRQs are just thrown away, while
we should at least make sure to try to consume them when the SDIO card has
been system resumed. Fix this by queueing a sdio_irq_work() after we system
resumed the SDIO card.

Tested-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

mmc: core: Clarify that the ->ack_sdio_irq() callback is mandatory

For the MMC_CAP2_SDIO_IRQ_NOTHREAD case and when using sdio_signal_irq(),
the ->ack_sdio_irq() is already mandatory, which was not the case for those
host drivers that called sdio_run_irqs() directly.

As there are no longer any drivers calling sdio_run_irqs(), let's clarify
the code by dropping the unnecessary check and explicitly state that the
callback is mandatory in the header file.

Tested-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

mmc: core: Clarify sdio_irq_pending flag for MMC_CAP2_SDIO_IRQ_NOTHREAD

The sdio_irq_pending flag is used to let host drivers indicate that it has
signaled an IRQ. If that is the case and we only have a single SDIO func
that have claimed an SDIO IRQ, our assumption is that we can avoid reading
the SDIO_CCCR_INTx register and just call the SDIO func irq handler
immediately. This makes sense, but the flag is set/cleared in a somewhat
messy order, let's fix that up according to below.

First, the flag is currently set in sdio_run_irqs(), which is executed as a
work that was scheduled from sdio_signal_irq(). To make it more implicit
that the host have signaled an IRQ, let's instead immediately set the flag
in sdio_signal_irq(). This also makes the behavior consistent with host
drivers that uses the legacy, mmc_signal_sdio_irq() API. This have no
functional impact, because we don't expect host drivers to call
sdio_signal_irq() until after the work (sdio_run_irqs()) have been executed
anyways.

Second, currently we never clears the flag when using the sdio_run_irqs()
work, but only when using the sdio_irq_thread(). Let make the behavior
consistent, by moving the flag to be cleared inside the common
process_sdio_pending_irqs() function. Additionally, tweak the behavior of
the flag slightly, by avoiding to clear it unless we processed the SDIO
IRQ. The purpose with this at this point, is to keep the information about
whether there have been an SDIO IRQ signaled by the host, so at system
resume we can decide to process it without reading the SDIO_CCCR_INTx
register.

Tested-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

mmc: core: Move code to get pending SDIO IRQs to a function

To improve code quality, let's move the code that gets pending SDIO IRQs
from process_sdio_pending_irqs() into a dedicated function.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
[Ulf: Converted function into static]
Tested-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

mmc: sdio: Turn sdio_run_irqs() into static

All external users of sdio_run_irqs() have converted into using the
preferred sdio_signal_irq() interface, thus not calling the function
directly any more. Avoid further new users of it, by turning it into
static.

Suggested-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

mmc: core: Prevent processing SDIO IRQs when the card is suspended

Processing of SDIO IRQs must obviously be prevented while the card is
system suspended, otherwise we may end up trying to communicate with an
uninitialized SDIO card.

Reports throughout the years shows that this is not only a theoretical
problem, but a real issue. So, let's finally fix this problem, by keeping
track of the state for the card and bail out before processing the SDIO
IRQ, in case the card is suspended.

Cc: stable@vger.kernel.org
Reported-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mmc: update sdio_claim_irq documentation

Update documentation for sdio_claim_irq to downgrade the wording
about doing recursive claims in an IRQ handler from 'must not' to
'should not'. This clarifies that recursive claims are supported,
but not the recommended (best) practice

Signed-off-by: Joel Cunningham <joel.cunningham@garmin.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

mmc: core: Introduce host claiming by context

Currently the host can be claimed by a task. Change this so that the host
can be claimed by a context that may or may not be a task. This provides
for the host to be claimed by a block driver queue to support blk-mq, while
maintaining compatibility with the existing use of mmc_claim_host().

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

mmc: sdio: Add API to manage SDIO IRQs from a workqueue

For hosts not supporting MMC_CAP2_SDIO_IRQ_NOTHREAD but MMC_CAP_SDIO_IRQ,
the SDIO IRQs are processed from a dedicated kernel thread. For these
cases, the host calls mmc_signal_sdio_irq() from its ISR to signal a new
SDIO IRQ.

Signaling an SDIO IRQ makes the host's ->enable_sdio_irq() callback to be
invoked to temporary disable the IRQs, before the kernel thread is woken up
to process it. When processing of the IRQs are completed, they are
re-enabled by the kernel thread, again via invoking the host's
->enable_sdio_irq().

The observation from this, is that the execution path is being unnecessary
complex, as the host driver already knows that it needs to temporary
disable the IRQs before signaling a new one. Moreover, replacing the kernel
thread with a work/workqueue would not only greatly simplify the code, but
also make it more robust.

To address the above problems, let's continue to build upon the support for
MMC_CAP2_SDIO_IRQ_NOTHREAD, as it already implements SDIO IRQs to be
processed without using the clumsy kernel thread and without the ping-pong
calls of the host's ->enable_sdio_irq() callback for each processed IRQ.

Therefore, let's add new API sdio_signal_irq(), which enables hosts to
signal/process SDIO IRQs by using a work/workqueue, rather than using the
kernel thread.

Add also a new host callback ->ack_sdio_irq(), which the work invokes when
the SDIO IRQs have been processed. This informs the host about when it
shall re-enable the SDIO IRQs. Potentially, we could re-use the existing
->enable_sdio_irq() callback instead of adding a new one, however it has
turned out that it's more convenient for hosts to get this information via
a separate callback.

Hosts that wants to use this new method to signal/process SDIO IRQs, must
enable MMC_CAP2_SDIO_IRQ_NOTHREAD and implement the ->ack_sdio_irq()
callback.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>

mmc: core: Prevent processing SDIO IRQs when none is claimed

In cases when MMC_CAP2_SDIO_IRQ_NOTHREAD is set, there is a minor window
for when the mmc host could call sdio_run_irqs(), while in fact an SDIO
func driver could have decided to released the SDIO IRQ via a call to
sdio_release_irq(). In this scenario, processing of the SDIO IRQs are done
even if there is none IRQ claimed, which is not what we want.

To prevent this from happen, close the window by validating that at least
one SDIO IRQs is claimed, before deciding to process them.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>

sched/headers: Prepare for new header dependencies before moving code to <uapi/linux/sched/types.h>

We are going to move scheduler ABI details to <uapi/linux/sched/types.h>,
which will be used from a number of .c files.

Create empty placeholder header that maps to <linux/types.h>.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

mmc: core: Move public functions from card.h to private headers

A significant amount of functions and other definitions are available
through the public mmc card.h header file. Let's slim down this public mmc
interface, as to prevent users from abusing it, by moving some of the
functions/definitions to private mmc header files.

This change concentrates on moving the functions into private mmc headers,
following changes may continue with additional clean-ups.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>

mmc: core: Move public functions from core.h to private headers

A significant amount of functions are available through the public mmc
core.h header file. Let's slim down this public mmc interface, as to
prevent users from abusing it, by moving some of the functions to private
mmc header files.

This change concentrates on moving the functions into private mmc headers,
following changes may continue with additional clean-ups, as an example
some functions can be turned into static.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>

mmc: core: remove BUG_ONs from sdio

BUG_ONs doesn't help anything except for stop the system from
running. If it occurs, it implies we should deploy proper error
handling for that. So this patch is gonna discard these meaningless
BUG_ONs and deploy error handling if needed.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

mmc: core: Remove MMC_CLKGATE

MMC_CLKGATE was once invented to save power by gating the bus clock at
request inactivity. At that time it served its purpose. The modern way to
deal with power saving for these scenarios, is by using runtime PM.

Nowadays, several host drivers have deployed runtime PM, but for those
that haven't and which still cares power saving at request inactivity,
it's certainly time to deploy runtime PM as it has been around for several
years now.

To simplify code to mmc core and thus decrease maintenance efforts, this
patch removes all code related to MMC_CLKGATE.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

mmc: Convert pr_warning to pr_warn

Use the much more common pr_warn instead of pr_warning.

Other miscellanea:

o Coalesce formats
o Realign arguments
o Remove extra spaces when coalescing formats

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

mmc: core: sdio: Fix unconditional wake_up_process() on sdio thread

781e989cf59 ("mmc: sdhci: convert to new SDIO IRQ handling") and
bf3b5ec66bd ("mmc: sdio_irq: rework sdio irq handling") disabled
the use of our own custom threaded IRQ handler, but left in an
unconditional wake_up_process() on that handler at resume-time.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=80151

In addition, the check for MMC_CAP_SDIO_IRQ capability is added
before enable sdio IRQ.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Chris Ball <chris@printf.net>
Signed-off-by: Fu Zhonghui <zhonghui.fu@linux.intel.com>
Cc: <stable@vger.kernel.org> # v3.16+
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

mmc: sdio_irq: rework sdio irq handling

Rather than the SDIO support spawning it's own thread for handling card
interrupts, use the generic IRQ infrastructure for this, triggering it
from the host interface's interrupt handling directly.

This avoids a race between the parent thread waiting to receive an
interrupt response from the card, and the slow startup from the sdio
irq thread, which can occur as a result of high system load (eg, while
udev is running.)

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Markus Pargmann <mpa@pengutronix.de>
Tested-by: Stephen Warren <swarren@nvidia.com>
[Ulf Hansson] Resolved conflict
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>

mmc: sdio: add a quirk for broken SDIO_CCCR_INTx polling

Polling SDIO_CCCR_INTx could create a fake interrupt with Marvell
SD8797 card. Add a quirk to handle this case. The fixup here is
to issue a dummy CMD52 read to function 0 register 0xff, and this
dummy read must be right after SDIO_CCCR_INTx is read.

Patch has been verified on a dw_mmc controller (Samsung Chromebook)
with MMC_CAP_SDIO_IRQ disabled.

Signed-off-by: Bing Zhao <bzhao@marvell.com>
Reviewed-by: Paul Stewart <pstew@chromium.org>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>

mmc: sdio: avoid spurious calls to interrupt handlers

Commit 06e8935feb ("optimized SDIO IRQ handling for single irq")
introduced some spurious calls to SDIO function interrupt handlers,
such as when the SDIO IRQ thread is started, or the safety check
performed upon a system resume. Let's add a flag to perform the
optimization only when a real interrupt is signaled by the host
driver and we know there is no point confirming it.

Reported-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

mmc: core: Ensure clocks are always enabled before host interaction

Ensure clocks are always enabled before any interaction with the
host controller driver. This makes sure that there is no race
between host execution and the core layer turning off clocks
in different context with clock gating framework.

Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Per Forlin <per.forlin@stericsson.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

mmc: Add export.h for EXPORT_SYMBOL/THIS_MODULE as required

These two basic defines were everywhere, simply because module.h
was also everywhere. But we are cleaning up the latter. So make
the exporters actually call out their need for the include.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

mmc: replace printk with appropriate display macro

All the files using printk function for displaying kernel messages
in the mmc driver have been replaced with corresponding macro.

Signed-off-by: Girish K S <girish.shivananjappa@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

mmc: sdio: optimized SDIO IRQ handling for single irq

If there is only 1 function interrupt registered it is possible to
improve performance by directly calling the irq handler and avoiding
the overhead of reading the CCCR registers.

Signed-off-by: Per Forlin <per.forlin@linaro.org>
Acked-by: Ulf Hansson <ulf.hansson@stericsson.com>
Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>

sdio: give sdio irq thread a host specific name

There is one thread per host controller so make sure they all get
unique names.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

sdio: make sleep on error interruptable

Make sure we can be woken from the forced sleep that is done on errors.
Removing a card often results in -ENOMEDIUM or -EILSEQ so we previously
locked up the removal process for a second.

We could completely exit on -ENOMEDIUM, but it might be a transient
glitch so treat it like any other error.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

mmc: use shorter, equivalent set_current_state()

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

sdio: make the IRQ thread more resilient in the presence of bad states

Currently we print a message about some bad states wrt function IRQ
handlers but return 0 from process_sdio_pending_irqs() nevertheless.
This can lead to an infinite loop as nothing might have cleared the
condition for the pending card interrupt from the host controller by
the time host->ops->enable_sdio_irq(host, 1) is called.

Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

sdio: fix IRQ diagnostic message

If func is actually null we won't get much from sdio_func_id(func).

Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

sdio: adaptive interrupt polling

The interrupt polling frequency is a compromise between power usage and
interrupt latency. Unfortunately, it affects throughput rather severely
for devices which require an interrupt for every chunk of data.

By making the polling frequency adaptive, we get better throughput with
those devices without sacficing too much power. Polling will quickly
increase when there is an actual interrupt, and slowly fall back to the
idle frequency when the interrupts stop coming.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

mmc: replace BUG_ON with WARN_ON

Replace all cases of BUG_ON with WARN_ON where there is a chance
(with varying degrees of slim) that the kernel can continue without
incidence.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

sdio: add interface for host side SDIO interrupt reporting

Signed-off-by: Nicolas Pitre <npitre@mvista.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

sdio: core support for SDIO function interrupt

Signed-off-by: Nicolas Pitre <npitre@mvista.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>