Debugfs console_log uses devm memory (e.g. debug_info in
cros_ec_console_log_poll()).  However, lifecycles of device and debugfs
are independent.  An use-after-free issue is observed if userland
program operates the debugfs after the memory has been freed.

The call trace:
 do_raw_spin_lock
 _raw_spin_lock_irqsave
 remove_wait_queue
 ep_unregister_pollwait
 ep_remove
 do_epoll_ctl

A Python example to reproduce the issue:
... import select
... p = select.epoll()
... f = open('/sys/kernel/debug/cros_scp/console_log')
... p.register(f, select.POLLIN)
... p.poll(1)
[(4, 1)]                    # 4=fd, 1=select.POLLIN

[ shutdown cros_scp at the point ]

... p.poll(1)
[(4, 16)]                   # 4=fd, 16=select.POLLHUP
... p.unregister(f)

An use-after-free issue raises here.  It called epoll_ctl with
EPOLL_CTL_DEL which in turn to use the workqueue in the devm (i.e.
log_wq).

Detaches log reader's workqueue from devm to make sure it is persistent
even if the device has been removed.

Signed-off-by: Tzung-Bi Shih <tzungbi@google.com>
Reviewed-by: Guenter Roeck <groeck@google.com>
Link: https://lore.kernel.org/r/20220209051130.386175-1-tzungbi@google.com
Signed-off-by: Benson Leung <bleung@chromium.org>

When EC does not support uptime command (EC_CMD_GET_UPTIME_INFO),
do not create the uptime sysfs entry point.
User space application will not probe the file needlessly.

The EC console log will not contain EC_CMD_GET_UPTIME_INFO anymore.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

This header file now only includes the cros_ec_dev struct, however, is the
'include/linux/platform_data/cros_ec_proto.h' who contains the definition of
all the Chrome OS EC related structs. There is no reason to have a
separate include for this struct so move to the place where other
structs are defined. That way, we can remove the include itself, but also
simplify the common pattern

    #include <linux/mfd/cros_ec.h>
    #include <linux/platform_data/cros_ec_proto.h>

for a single include

    #include <linux/platform_data/cros_ec_proto.h>

The changes to remove the cros_ec.h include were generated with the
following shell script:

    git grep -l "<linux/mfd/cros_ec.h>" | xargs sed -i '/<linux\/mfd\/cros_ec.h>/d'

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Sebastian Reichel <sre@kernel.org>
Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

There is a bit of mess between cros-ec mfd includes and platform
includes. For example, we have a linux/mfd/cros_ec.h include that
exports the interface implemented in platform/chrome/cros_ec_proto.c. Or
we have a linux/mfd/cros_ec_commands.h file that is non related to the
multifunction device (in the sense that is not exporting any function of
the mfd device). This causes crossed includes between mfd and
platform/chrome subsystems and makes the code difficult to read, apart
from creating 'curious' situations where a platform/chrome driver includes
a linux/mfd/cros_ec.h file just to get the exported functions that are
implemented in another platform/chrome driver.

In order to have a better separation on what the cros-ec multifunction
driver does and what the cros-ec core provides move and rework the
affected includes doing:

 - Move cros_ec_commands.h to include/linux/platform_data/cros_ec_commands.h
 - Get rid of the parts that are implemented in the platform/chrome/cros_ec_proto.c
   driver from include/linux/mfd/cros_ec.h to a new file
   include/linux/platform_data/cros_ec_proto.h
 - Update all the drivers with the new includes, so
   - Drivers that only need to know about the protocol include
     - linux/platform_data/cros_ec_proto.h
     - linux/platform_data/cros_ec_commands.h
   - Drivers that need to know about the cros-ec mfd device also include
     - linux/mfd/cros_ec.h

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Tested-by: Gwendal Grignou <gwendal@chromium.org>
Series changes: 3
- Fix dereferencing pointer to incomplete type 'struct cros_ec_dev' (lkp)
Signed-off-by: Lee Jones <lee.jones@linaro.org>

For ECs that support it, the EC returns the number of slp_s0
transitions and whether or not there was a timeout in the resume
response. Expose the last resume result to usermode via debugfs so
that usermode can detect and report S0ix timeouts.

Signed-off-by: Evan Green <evgreen@chromium.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

Fixes: 909447f683b3 ("platform/chrome: cros_ec_debugfs: Add debugfs entry to retrieve EC uptime")
Signed-off-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

kernel-doc comments have a prescribed format. To be _particularly_
correct we should also capitalise the brief description and terminate
it with a period.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

The new debugfs entry 'uptime' is being made available to userspace so that
a userspace daemon can synchronize EC logs with host time.

Signed-off-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
[rework based on Tim's first approach]
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: Tim Wawrzynczak <twawrzynczak@chromium.org>

Fix sparse warning:

drivers/platform/chrome/cros_ec_debugfs.c:256:30: warning: symbol 'cros_ec_console_log_fops' was not declared. Should it be static?
drivers/platform/chrome/cros_ec_debugfs.c:265:30: warning: symbol 'cros_ec_pdinfo_fops' was not declared. Should it be static?
drivers/platform/chrome/cros_ec_lightbar.c:550:24: warning: symbol 'cros_ec_lightbar_attr_group' was not declared. Should it be static?
drivers/platform/chrome/cros_ec_sysfs.c:338:24: warning: symbol 'cros_ec_attr_group' was not declared. Should it be static?
drivers/platform/chrome/cros_ec_vbc.c:104:24: warning: symbol 'cros_ec_vbc_attr_group' was not declared. Should it be static?
drivers/platform/chrome/cros_ec_lpc.c:408:25: warning: symbol 'cros_ec_lpc_pm_ops' was not declared. Should it be static?

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Benson Leung <bleung@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

Pull chrome platform updates from Benson Leung:
 "CrOS EC:
   - Add EC host command support using rpmsg
   - Add new CrOS USB PD logging driver
   - Transfer spi messages at high priority
   - Add support to trace CrOS EC commands
   - Minor fixes and cleanups in protocol and debugfs

  Wilco EC:
   - Standardize Wilco EC mailbox interface
   - Add h1_gpio status to debugfs"

* tag 'tag-chrome-platform-for-v5.2' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/chrome-platform/linux:
  platform/chrome: cros_ec_proto: Add trace event to trace EC commands
  platform/chrome: cros_ec_debugfs: Use cros_ec_cmd_xfer_status helper
  platform/chrome: cros_ec: Add EC host command support using rpmsg
  platform/chrome: wilco_ec: Add h1_gpio status to debugfs
  platform/chrome: wilco_ec: Standardize mailbox interface
  platform/chrome: cros_ec_proto: check for NULL transfer function
  platform/chrome: Add CrOS USB PD logging driver
  platform/chrome: cros_ec_spi: Transfer messages at high priority
  platform/chrome: cros_ec_debugfs: no need to check return value of debugfs_create functions
  platform/chrome: cros_ec_debugfs: Remove dev_warn when console log is not supported