coresight: Fix CTI module refcount leak by making it a helper device

The CTI module has some hard coded refcounting code that has a leak.
For example running perf and then trying to unload it fails:

perf record -e cs_etm// -a -- ls
rmmod coresight_cti

rmmod: ERROR: Module coresight_cti is in use

The coresight core already handles references of devices in use, so by
making CTI a normal helper device, we get working refcounting for free.

Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230425143542.2305069-14-james.clark@arm.com

coresight: cti: Remove atomic type from enable_req_count

enable_req_count is only ever accessed inside the spinlock, so to avoid
confusion that there are concurrent accesses and simplify the code,
change it to an int.

One access outside of the spinlock is in enable_show() which appears to
allow partially written data to be displayed between enable_req_count,
powered and enabled so move this one inside the spin lock too.

Signed-off-by: James Clark <james.clark@arm.com>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230110110736.2709917-4-james.clark@arm.com

coresight: cti: Add PM runtime call in enable_store

In commit 6746eae4bbad ("coresight: cti: Fix hang in cti_disable_hw()")
PM runtime calls are removed from cti_enable_hw/cti_disable_hw. When
enabling CTI by writing enable sysfs node, clock for accessing CTI
register won't be enabled. Device will crash due to register access
issue. Add PM runtime call in enable_store to fix this issue.

Fixes: 6746eae4bbad ("coresight: cti: Fix hang in cti_disable_hw()")
Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
[Change to only call pm_runtime_put if a disable happened]
Tested-by: Jinlong Mao <quic_jinlmao@quicinc.com>
Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230110110736.2709917-3-james.clark@arm.com

coresight: cti-sysfs: Mark coresight_cti_reg_store() as __maybe_unused

When building without CONFIG_CORESIGHT_CTI_INTEGRATION_REGS, there is a
warning about coresight_cti_reg_store() being unused in the file:

drivers/hwtracing/coresight/coresight-cti-sysfs.c:184:16: warning: 'coresight_cti_reg_store' defined but not used [-Wunused-function]
184 | static ssize_t coresight_cti_reg_store(struct device *dev,
| ^~~~~~~~~~~~~~~~~~~~~~~

This is expected as coresight_cti_reg_store() is only used in the
coresight_cti_reg_rw macro, which is only used in a block guarded by
CONFIG_CORESIGHT_CTI_INTEGRATION_REGS. Mark coresight_cti_reg_store() as
__maybe_unused to clearly indicate that the function may be unused
depending on the configuration.

Fixes: fbca79e55429 ("coresight: cti-sysfs: Re-use same functions for similar sysfs register accessors")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: James Clark <james.clark@arm.com>
Link: https://lore.kernel.org/r/20220901195055.1932340-1-nathan@kernel.org
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

coresight: cti-sysfs: Re-use same functions for similar sysfs register accessors

Currently each accessor macro creates an identical function which wastes
space in the text area and pollutes the ftrace function name list.
Change it so that the same function is used, but the register to access
is passed in as parameter rather than baked into each function.

Note that only the single accessor is used here and not
csdev_access_relaxed_read_pair() like in the previous commit, so
so a single unsigned offset value is stored instead.

Signed-off-by: James Clark <james.clark@arm.com>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Link: https://lore.kernel.org/r/20220830172614.340962-5-james.clark@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

coresight: cti: Initialize dynamic sysfs attributes

With LOCKDEP enabled, CTI driver triggers the following splat due
to uninitialized lock class for dynamically allocated attribute
objects.

[ 5.372901] coresight etm0: CPU0: ETM v4.0 initialized
[ 5.376694] coresight etm1: CPU1: ETM v4.0 initialized
[ 5.380785] coresight etm2: CPU2: ETM v4.0 initialized
[ 5.385851] coresight etm3: CPU3: ETM v4.0 initialized
[ 5.389808] BUG: key ffff00000564a798 has not been registered!
[ 5.392456] ------------[ cut here ]------------
[ 5.398195] DEBUG_LOCKS_WARN_ON(1)
[ 5.398233] WARNING: CPU: 1 PID: 32 at kernel/locking/lockdep.c:4623 lockdep_init_map_waits+0x14c/0x260
[ 5.406149] Modules linked in:
[ 5.415411] CPU: 1 PID: 32 Comm: kworker/1:1 Not tainted 5.9.0-12034-gbbe85027ce80 #51
[ 5.418553] Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT)
[ 5.426453] Workqueue: events amba_deferred_retry_func
[ 5.433299] pstate: 40000005 (nZcv daif -PAN -UAO -TCO BTYPE=--)
[ 5.438252] pc : lockdep_init_map_waits+0x14c/0x260
[ 5.444410] lr : lockdep_init_map_waits+0x14c/0x260
[ 5.449007] sp : ffff800012bbb720
...

[ 5.531561] Call trace:
[ 5.536847] lockdep_init_map_waits+0x14c/0x260
[ 5.539027] __kernfs_create_file+0xa8/0x1c8
[ 5.543539] sysfs_add_file_mode_ns+0xd0/0x208
[ 5.548054] internal_create_group+0x118/0x3c8
[ 5.552307] internal_create_groups+0x58/0xb8
[ 5.556733] sysfs_create_groups+0x2c/0x38
[ 5.561160] device_add+0x2d8/0x768
[ 5.565148] device_register+0x28/0x38
[ 5.568537] coresight_register+0xf8/0x320
[ 5.572358] cti_probe+0x1b0/0x3f0

...

Fix this by initializing the attributes when they are allocated.

Fixes: 3c5597e39812 ("coresight: cti: Add connection information to sysfs")
Reported-by: Leo Yan <leo.yan@linaro.org>
Tested-by: Leo Yan <leo.yan@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20201029164559.1268531-2-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

coresight: Include required headers in C files

We should include headers that C files use in the C files that use them
and avoid relying on implicit includes as much as possible. This helps
avoid compiler errors in the future about missing declarations when
header files change includes in the future.

Cc: Douglas Anderson <dianders@chromium.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200518180242.7916-20-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

coresight: Don't initialize variables unnecessarily

These variables are assigned again before they're used. Leave them
unassigned at first so that the compiler can detect problems in the
future with use before initialization.

Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200518180242.7916-18-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

coresight: Mark some functions static

These functions aren't used outside the file they're in. Mark them
static to indicate as such and silence tools like sparse.

Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
[Dropped changes in coresight-cti.c and coresight-etb10.c]
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200518180242.7916-17-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

coresight: cti: Add connection information to sysfs

Dynamically adds sysfs attributes for all connections defined in the CTI.

Each connection has a triggers<N> sub-directory with name, in_signals,
in_types, out_signals and out_types as read-only parameters in the
directory. in_ or out_ parameters may be omitted if there are no in or
out signals for the connection.

Additionally each device has a nr_cons in the connections sub-directory.

This allows clients to explore the connection and trigger signal details
without needing to refer to device tree or specification of the device.

Standardised type information is provided for certain common functions -
e.g. snk_full for a trigger from a sink indicating full. Otherwise type
defaults to genio.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200320165303.13681-10-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

coresight: cti: Add device tree support for custom CTI

Adds support for CTIs whose connections are implementation defined at
hardware design time, and not constrained by v8 architecture.

These CTIs have no standard connection setup, all the settings have to
be defined in the device tree files. The patch creates a set of connections
and trigger signals based on the information provided.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200320165303.13681-8-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

coresight: cti: Add sysfs trigger / channel programming API

Adds a user API to allow programming of CTI by trigger ID and
channel number. This will take the channel and trigger ID supplied
by the user and program the appropriate register values.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200320165303.13681-5-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

coresight: cti: Add sysfs access to program function registers

Adds in sysfs programming support for the CTI function register sets.
Allows direct manipulation of channel / trigger association registers.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200320165303.13681-4-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

coresight: cti: Add sysfs coresight mgmt register access

Adds sysfs access to the coresight management registers.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200320165303.13681-3-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

coresight: cti: Initial CoreSight CTI Driver

This introduces a baseline CTI driver and associated configuration files.

Uses the platform agnostic naming standard for CoreSight devices, along
with a generic platform probing method that currently supports device
tree descriptions, but allows for the ACPI bindings to be added once these
have been defined for the CTI devices.

Driver will probe for the device on the AMBA bus, and load the CTI driver
on CoreSight ID match to CTI IDs in tables.

Initial sysfs support for enable / disable provided.

Default CTI interconnection data is generated based on hardware
register signal counts, with no additional connection information.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200320165303.13681-2-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>