staging: greybus: Remove usage of the deprecated ida_simple_xx() API

ida_alloc() and ida_free() should be preferred to the deprecated
ida_simple_get() and ida_simple_remove().

Note that the upper limit of ida_simple_get() is exclusive, buInputt the one of
ida_alloc_range()/ida_alloc_max() is inclusive. So a -1 has been added when
needed.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/2e7bbdaf8a495bb1273396395b5c779363287581.1705350141.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: greybus: use after free in gb_audio_manager_remove_all()

When we call kobject_put() and it's the last reference to the kobject
then it calls gb_audio_module_release() and frees module. We dereference
"module" on the next line which is a use after free.

Fixes: c77f85bbc91a ("greybus: audio: Fix incorrect counting of 'ida'")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Vaibhav Agarwal <vaibhav.sr@gmail.com>
Link: https://lore.kernel.org/r/20200205123217.jreendkyxulqsool@kili.mountain
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: greybus: remove redundant assignment to variable is_empty

The variable is_empty is being initialized with a value that is never
read and it is being updated later with a new value. The
initialization is redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Vaibhav Agarwal <vaibhav.sr@gmail.com>
Reviewed-by: Mark Greer <mgreer@animalcreek.com>
Link: https://lore.kernel.org/r/20190704133031.28809-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: greybus: audio_manager: fix a missing check of ida_simple_get

ida_simple_get could fail. The fix inserts a check for its
return value.

Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Reviewed-by: Vaibhav Agarwal <vaibhav.sr@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: greybus: Remove redundant license text

Now that the SPDX tag is in all greybus files, that identifies the
license in a specific and legally-defined manner. So the extra GPL text
wording can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text. And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Vaibhav Hiremath <hvaibhav.linux@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Acked-by: Vaibhav Agarwal <vaibhav.sr@gmail.com>
Acked-by: David Lin <dtwlin@gmail.com>
Acked-by: Johan Hovold <johan@kernel.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Mark Greer <mgreer@animalcreek.com>
Acked-by: Rui Miguel Silva <rmfrfs@gmail.com>
Acked-by: "Bryan O'Donoghue" <pure.logic@nexus-software.ie>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: greybus: add SPDX identifiers to all greybus driver files

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/staging/greybus files files with the correct SPDX
license identifier based on the license text in the file itself. The
SPDX identifier is a legally binding shorthand, which can be used
instead of the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Vaibhav Hiremath <hvaibhav.linux@gmail.com>
Cc: "Bryan O'Donoghue" <pure.logic@nexus-software.ie>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Acked-by: Vaibhav Agarwal <vaibhav.sr@gmail.com>
Acked-by: David Lin <dtwlin@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Acked-by: Johan Hovold <johan@kernel.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Mark Greer <mgreer@animalcreek.com>
Acked-by: Rui Miguel Silva <rmfrfs@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

greybus: audio: don't inclide rwlock.h directly.

rwlock.h should not be included directly. Instead linux/splinlock.h
should be included. One thing it does is to break the RT build.

Cc: Vaibhav Agarwal <vaibhav.sr@gmail.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Alex Elder <elder@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: greybus-dev@lists.linaro.org
Cc: devel@driverdev.osuosl.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

greybus: audio: gb_manager: Use valid argument while removing ida allocated id.

module->id is used as an argument to ida_simple_remove(). Since module
is already dereferenced, module->id might contain invalid data. So fix
this.

Fixes: da4cc2d0b066 ("audio:gb_manager: Use proper locking around kobject_xxx")
Signed-off-by: Vaibhav Agarwal <vaibhav.agarwal@linaro.org>
Reviewed-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

greybus: audio: Fix incorrect counting of 'ida'

Function gb_audio_manager_remove_all() to remove all audio modules,
doesn't control correctly 'ida' counting.

Signed-off-by: Dinko Mironov <dmironov@mm-sol.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

greybus: audio:gb_manager: Use proper locking around kobject_xxx

read/write_lock_irqsave mechanism was used to protect modules
list & kobject_xxx() in gb_audio_manager. Since kobject_xxx calls
can sleep spin_lock variants can't be used there. So use rw_sem
for protecting modules_list.

Signed-off-by: Vaibhav Agarwal <vaibhav.agarwal@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

greybus: audio_manager: add missing header

There's a definition missing in audio_manager causing the kernel build
to fail:

CC [M] ./greybus/audio_manager.o
./greybus/audio_manager.c:22:8: warning: type defaults to 'int' in declaration of 'DEFINE_IDA' [-Wimplicit-int]
error, forbidden warning: audio_manager.c:22
./kernel/scripts/Makefile.build:308: recipe for target './greybus/audio_manager.o' failed

Including linux/idr.h fixes the issue.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

greybus: audio_manager: use an 'ida' for the module id

Every time we hotplug an audio module, we get a new audio module id. We
should recycle them instead of just constantly incrementing the number
so we don't see things like:
[178016.832580] Created audio module #6124
in the kernel logs.

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

greybus: audio: Add Audio Manager

This is a simple module that keeps a list of connected GB audio
modules.

Whenever a device is attached, an appropriate uevent is sent to
userspace:

UDEV [4941.803215] add /kernel/gb_audio_manager/0 (gb_audio_manager)
ACTION=add
CPORT=99
DEVICES=0x10
DEVPATH=/kernel/gb_audio_manager/0
NAME=naim
PID=64
SEQNUM=1828
SLOT=2
SUBSYSTEM=gb_audio_manager
USEC_INITIALIZED=802416
VID=128

And whenever removed:

UDEV [4941.836588] remove /kernel/gb_audio_manager/0 (gb_audio_manager)
ACTION=remove
DEVPATH=/kernel/gb_audio_manager/0
SEQNUM=1833
SUBSYSTEM=gb_audio_manager
USEC_INITIALIZED=835681

The API consists of functions for adding, removing and inspecting
added device module descriptions (struct gb_audio_module):

int gb_audio_manager_add(struct gb_audio_module_descriptor *desc);
int gb_audio_manager_remove(int id);
int gb_audio_manager_remove_all(void);
struct gb_audio_module* gb_audio_manager_get_module(int id);
void gb_audio_manager_put_module(struct gb_audio_module *module);
int gb_audio_manager_dump_module(int id);
void gb_audio_manager_dump_all(void);

Devices can be inspected through sysfs in /sys/kernel/gb_audio_manager/{id}/*

If GB_AUDIO_MANAGER_SYSFS is exported as 'true', managing devices can be done
via the SYSFS as well. For instance:

echo name=naim slot=2 vid=128 pid=64 cport=99 devices=0x10 > /sys/kernel/gb_audio_manager/add
echo all > /sys/kernel/gb_audio_manager/dump
echo 2 > /sys/kernel/gb_audio_manager/dump
echo 2 > /sys/kernel/gb_audio_manager/remove

Signed-off-by: Svetlin Ankov <ankov_svetlin@projectara.com>
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>