hwmon: (xgene-hwmon) Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.
To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new() which already returns void. Eventually after all drivers
are converted, .remove_new() is renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230918085951.1234172-25-u.kleine-koenig@pengutronix.de
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (xgene) Migrate to use generic PCC shmem related macros

Use the newly defined common and generic PCC shared memory region
related macros in this driver to replace the locally defined ones.

Cc: Jean Delvare <jdelvare@suse.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230927-pcc_defines-v2-3-0b8ffeaef2e5@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

hwmon: (xgene) Fix ioremap and memremap leak

Smatch reports:

drivers/hwmon/xgene-hwmon.c:757 xgene_hwmon_probe() warn:
'ctx->pcc_comm_addr' from ioremap() not released on line: 757.

This is because in drivers/hwmon/xgene-hwmon.c:701 xgene_hwmon_probe(),
ioremap and memremap is not released, which may cause a leak.

To fix this, ioremap and memremap is modified to devm_ioremap and
devm_memremap.

Signed-off-by: Tianyi Jing <jingfelix@hust.edu.cn>
Reviewed-by: Dongliang Mu <dzm91@hust.edu.cn>
Link: https://lore.kernel.org/r/20230318143851.2191625-1-jingfelix@hust.edu.cn
[groeck: Fixed formatting and subject]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (xgene) Fix use after free bug in xgene_hwmon_remove due to race condition

In xgene_hwmon_probe, &ctx->workq is bound with xgene_hwmon_evt_work.
Then it will be started.

If we remove the driver which will call xgene_hwmon_remove to clean up,
there may be unfinished work.

The possible sequence is as follows:

Fix it by finishing the work before cleanup in xgene_hwmon_remove.

CPU0 CPU1

|xgene_hwmon_evt_work
xgene_hwmon_remove |
kfifo_free(&ctx->async_msg_fifo);|
|
|kfifo_out_spinlocked
|//use &ctx->async_msg_fifo
Fixes: 2ca492e22cb7 ("hwmon: (xgene) Fix crash when alarm occurs before driver probe")
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
Link: https://lore.kernel.org/r/20230310084007.1403388-1-zyytlz.wz@163.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (xgene-hwmon) Add free before exiting xgene_hwmon_probe

Call kfifo_free(&ctx->async_msg_fifo) before error exiting
instead of returning directly.

Signed-off-by: Peiwei Hu <jlu.hpw@foxmail.com>
Link: https://lore.kernel.org/r/tencent_C851C0324431466CBC22D60C5C6AC4A8E808@qq.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

mailbox: pcc: Use PCC mailbox channel pointer instead of standard

Now that we have all the shared memory region information populated in
the pcc_mbox_chan, let us propagate the pointer to the same as the
return value to pcc_mbox_request channel.

This eliminates the need for the individual users of PCC mailbox to
parse the PCCT subspace entries and fetch the shmem information. This
also eliminates the need for PCC mailbox controller to set con_priv to
PCCT subspace entries. This is required as con_priv is private to the
controller driver to attach private data associated with the channel and
not meant to be used by the mailbox client/users.

Let us convert all the users of pcc_mbox_{request,free}_channel to use
new interface.

Cc: Jean Delvare <jdelvare@suse.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Wolfram Sang <wsa@kernel.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

hwmon: replace snprintf in show functions with sysfs_emit

coccicheck complains about the use of snprintf() in sysfs
show functions.

drivers/hwmon/ina3221.c:701:8-16: WARNING: use scnprintf or sprintf

This results in a large number of patch submissions. Fix it all in
one go using the following coccinelle rules. Use sysfs_emit instead
of scnprintf or sprintf since that makes more sense.

@depends on patch@
identifier show, dev, attr, buf;
@@

ssize_t show(struct device *dev, struct device_attribute *attr, char *buf)
{
<...
return
- snprintf(buf, \( PAGE_SIZE \| PAGE_SIZE - 1 \),
+ sysfs_emit(buf,
...);
...>
}

@depends on patch@
identifier show, dev, attr, buf, rc;
@@

ssize_t show(struct device *dev, struct device_attribute *attr, char *buf)
{
<...
rc =
- snprintf(buf, \( PAGE_SIZE \| PAGE_SIZE - 1 \),
+ sysfs_emit(buf,
...);
...>
}

While at it, remove unnecessary braces and as well as unnecessary
else after return statements to address checkpatch warnings in the
resulting patch.

Cc: Zihao Tang <tangzihao1@hisilicon.com>
Cc: Jay Fang <f.fangjian@huawei.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (xgene) Drop bogus __refdata annotation

As the X-Gene hardware monitoring driver does not have any code or data
located in initmem, there is no need to annotate the xgene_hwmon_driver
structure with __refdata. Drop the annotation, to avoid suppressing
future section warnings.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20201211133531.2970027-1-geert+renesas@glider.be
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13

Based on 2 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 this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details you
should have received a copy of the gnu general public license along
with this program if not see http www gnu org licenses

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 this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details [based]
[from] [clk] [highbank] [c] you should have received a copy of the
gnu general public license along with this program if not see http
www gnu org licenses

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 355 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Jilayne Lovejoy <opensource@jilayne.com>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190519154041.837383322@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

hwmon: (xgene) Minor clean up of ifdef and acpi_match_table reference

This patch removes the un-necessary ifdef CONFIG_ACPI and directly
uses the acpi_match_table from the driver pdev.

Signed-off-by: Hoan Tran <hotran@apm.com>
[groeck: Dropped unnecessary initialization]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (xgene) Support hwmon v2

This patch supports xgene-hwmon v2 which uses the non-cachable memory
as the PCC shared memory.

Signed-off-by: Hoan Tran <hotran@apm.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (xgene) Fix up error handling path mixup in 'xgene_hwmon_probe()'

Commit 2ca492e22cb7 has moved the call to 'kfifo_alloc()' from after the
main 'if' statement to before it.
But it has not updated the error handling paths accordingly.

Fix all that:
- if 'kfifo_alloc()' fails we can return directly
- direct returns after 'kfifo_alloc()' must now go to 'out_mbox_free'
- 'goto out_mbox_free' must be replaced by 'goto out', otherwise the
'[pcc_]mbox_free_channel()' call will be missed.

Fixes: 2ca492e22cb7 ("hwmon: (xgene) Fix crash when alarm occurs before driver probe")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (xgene) access mailbox as RAM

The newly added hwmon driver fails to build in an allmodconfig
kernel:

ERROR: "memblock_is_memory" [drivers/hwmon/xgene-hwmon.ko] undefined!

According to comments in the code, the mailbox is a shared memory region,
not a set of MMIO registers, so we should use memremap() for mapping it
instead of ioremap or acpi_os_ioremap, and pointer dereferences instead
of readl/writel.

The driver already uses plain kernel pointers, so it's a bit unusual
to work with functions that operate on __iomem pointers, and this
fixes that part too.

I'm using READ_ONCE/WRITE_ONCE here to keep the existing behavior
regarding the ordering of the accesses from the CPU, but note that
there are no barriers (also unchanged from before).

I'm also keeping the endianness behavior, though I'm unsure whether
the message data was supposed to be in LE32 format in the first
place, it's possible this was meant to be interpreted as a byte
stream instead.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Hoan Tran <hotran@apm.com>
Tested-by: Hoan Tran <hotran@apm.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (xgene) Fix crash when alarm occurs before driver probe

The system crashes during probing xgene-hwmon driver when temperature
alarm interrupt occurs before.
It's because
- xgene_hwmon_probe() requests mailbox channel which also enables
the mailbox interrupt.
- As temperature alarm interrupt is pending, ISR runs and crashes when
accesses into invalid resourse as unmapped PCC shared memory.

This patch fixes this issue by saving this alarm message and scheduling a
bottom handler after xgene_hwmon_probe() finish.

Signed-off-by: Hoan Tran <hotran@apm.com>
Reported-by: Itaru Kitayama <itaru.kitayama@riken.jp>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: Add xgene hwmon driver

This patch adds hardware temperature and power reading support for
APM X-Gene SoC using the mailbox communication interface.

Signed-off-by: Hoan Tran <hotran@apm.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>