hwspinlock: omap: Use index to get hwspinlock pointer

For loops with multiple initializers and increments are hard to read
and reason about, simplify this by using the looping index to index
into the hwspinlock array.

Signed-off-by: Andrew Davis <afd@ti.com>
Link: https://lore.kernel.org/r/20240208165114.63148-4-afd@ti.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

hwspinlock: omap: Use devm_hwspin_lock_register() helper

This will unregister the HW spinlock on module exit automatically for us,
currently we manually unregister which can be error-prone if not done in
the right order. This also allows us to remove the remove callback.
Do that here.

Signed-off-by: Andrew Davis <afd@ti.com>
Link: https://lore.kernel.org/r/20240208165114.63148-3-afd@ti.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

hwspinlock: omap: Use devm_pm_runtime_enable() helper

This disables runtime PM on module exit automatically for us, currently
we manually disable runtime PM which can be error-prone if not done
in the right order or missed in some exit path. This also allows us
to simplify the probe exit path and remove callbacks. Do that here.

While here, as we can now return right after registering our hwspinlock,
simply return directly and remove the extra debug message.

Signed-off-by: Andrew Davis <afd@ti.com>
Link: https://lore.kernel.org/r/20240208165114.63148-2-afd@ti.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

hwspinlock: omap: Remove unneeded check for OF node

We do not use the OF node anymore, nor does it matter how
we got to probe, so remove the check for of_node.

Signed-off-by: Andrew Davis <afd@ti.com>
Link: https://lore.kernel.org/r/20240208165114.63148-1-afd@ti.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

hwspinlock: omap: 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 (mostly) ignored
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.

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>
Acked-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Link: https://lore.kernel.org/r/20230314180100.2865801-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

hwspinlock: omap: Emit only one error message for errors in .remove()

If a remove callback of a platform driver returns a non-zero value, the
driver core emits an error message, otherwise ignores the value and
completes unbinding the device.

As omap_hwspinlock_remove() already emits an error message, suppress the
core's error message by returning zero.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Link: https://lore.kernel.org/r/20230314180100.2865801-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

hwspinlock: omap: drop of_match_ptr for ID table

The driver can match only via the DT table so the table should be always
used and the of_match_ptr does not have any sense (this also allows ACPI
matching via PRP0001, even though it might not be relevant here).

drivers/hwspinlock/omap_hwspinlock.c:164:34: error: ‘omap_hwspinlock_of_match’ defined but not used [-Werror=unused-const-variable=]

Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230512164520.212312-1-krzysztof.kozlowski@linaro.org

hwspinlock: using pm_runtime_resume_and_get instead of pm_runtime_get_sync

Using pm_runtime_resume_and_get is more appropriate
for simplifing code

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Minghao Chi <chi.minghao@zte.com.cn>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220418105508.2558696-1-chi.minghao@zte.com.cn

hwspinlock: omap: Add support for K3 AM64x SoCs

The AM64x SoC contains a HwSpinlock IP instance in the MAIN domain,
and is a minor variant of the IP on the current TI K3 SoCs such as
AM64x, J721E or J7200 SoCs. The IP is not built with the K3 safety
feature in hardware, and has slightly different integration into
the overall SoC.

Add the support for this IP through a new compatible.

Signed-off-by: Suman Anna <s-anna@ti.com>
Link: https://lore.kernel.org/r/20210209172240.2305-3-s-anna@ti.com
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

hwspinlock: omap: Use devm_kzalloc() to allocate memory

Use devm_kzalloc() to allocate memory, which can simplify the error
handling.

Signed-off-by: Baolin Wang <baolin.wang7@gmail.com>
Link: https://lore.kernel.org/r/c066ad704c1a5fd52c3002cac80ddd59b3901b01.1578453062.git.baolin.wang7@gmail.com
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

hwspinlock: omap: Change to use devm_platform_ioremap_resource()

Use the new helper that wraps the calls to platform_get_resource()
and devm_ioremap_resource() together, which can simpify the code.
Meanwhile renaming the error label to make more sense after removing
iounmap().

Signed-off-by: Baolin Wang <baolin.wang7@gmail.com>
Link: https://lore.kernel.org/r/6c09c5034a7e68fdfc22d2cb5daa375bccb33a66.1578453062.git.baolin.wang7@gmail.com
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

hwspinlock/omap: Add a trace during probe

Add a debug level trace statement in the OMAP HwSpinlock driver
probe function to print the number of hwlocks on a successful
registration.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

hwspinlock/omap: Add support for TI K3 SoCs

A HwSpinlock IP is also present on the newer TI K3 AM65x and J721E
family of SoCs within the Main NavSS sub-module. Reuse the existing
OMAP Hwspinlock driver to extend the support for this IP on K3 AM65x
SoCs as well. The IP has slightly different bit-fields in the
SYSCONFIG and SYSSTATUS registers.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

treewide: Use struct_size() for kmalloc()-family

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
int stuff;
void *entry[];
};

instance = kmalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kmalloc(struct_size(instance, entry, count), GFP_KERNEL);

This patch makes the changes for kmalloc()-family (and kvmalloc()-family)
uses. It was done via automatic conversion with manual review for the
"CHECKME" non-standard cases noted below, using the following Coccinelle
script:

// pkey_cache = kmalloc(sizeof *pkey_cache + tprops->pkey_tbl_len *
// sizeof *pkey_cache->table, GFP_KERNEL);
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
identifier VAR, ELEMENT;
expression COUNT;
@@

- alloc(sizeof(*VAR) + COUNT * sizeof(*VAR->ELEMENT), GFP)
+ alloc(struct_size(VAR, ELEMENT, COUNT), GFP)

// mr = kzalloc(sizeof(*mr) + m * sizeof(mr->map[0]), GFP_KERNEL);
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
identifier VAR, ELEMENT;
expression COUNT;
@@

- alloc(sizeof(*VAR) + COUNT * sizeof(VAR->ELEMENT[0]), GFP)
+ alloc(struct_size(VAR, ELEMENT, COUNT), GFP)

// Same pattern, but can't trivially locate the trailing element name,
// or variable name.
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
expression SOMETHING, COUNT, ELEMENT;
@@

- alloc(sizeof(SOMETHING) + COUNT * sizeof(ELEMENT), GFP)
+ alloc(CHECKME_struct_size(&SOMETHING, ELEMENT, COUNT), GFP)

Signed-off-by: Kees Cook <keescook@chromium.org>

hwspinlock/omap: Switch to SPDX license identifier

Use the appropriate SPDX license identifier in the OMAP hwspinlock
driver source file and drop the previous boilerplate license text.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

hwspinlock/omap: add support for dt nodes

HwSpinlock IP is present only on OMAP4 and other newer SoCs,
which are all device-tree boot only. This patch adds the
base support for parsing the DT nodes, and removes the code
dealing with the traditional platform device instantiation.

Signed-off-by: Suman Anna <s-anna@ti.com>
[tony@atomide.com: ack for legacy file removal]
Acked-by: Tony Lindgren <tony@atomide.com>
[comment on the imperfect always-zero base_id]
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>

hwspinlock: drop owner assignment from platform_drivers

A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

hwspinlock/omap: enable module before reading SYSSTATUS register

The number of hwspinlocks are determined based on the value read
from the IP block's SYSSTATUS register. However, the module may
not be enabled and clocked, and the read may result in a bus error.

This particular issue is seen rather easily on AM33XX, since the
module wakeup is software controlled, and it is disabled out of
reset. Make sure the module is enabled and clocked before reading
the SYSSTATUS register.

Signed-off-by: Suman Anna <s-anna@ti.com>
[replace pm_runtime_put_sync with lenient pm_runtime_put]
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>

hwspinlock: remove use of __devexit

CONFIG_HOTPLUG is going away as an option so __devexit is no
longer needed.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

hwspinlock: remove use of __devinit

CONFIG_HOTPLUG is going away as an option so __devinit is no longer
needed.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

hwspinlock: remove use of __devexit_p

CONFIG_HOTPLUG is going away as an option so __devexit_p is no longer
needed.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

hwspinlock/omap: omap_hwspinlock_remove should be __devexit

Mark omap_hwspinlock_remove with __devexit (and use __devexit_p
appropriately) so the function can be discarded when the conditions are met.

Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>

hwspinlock/core: register a bank of hwspinlocks in a single API call

Hardware Spinlock devices usually contain numerous locks (known
devices today support between 32 to 256 locks).

Originally hwspinlock core required drivers to register (and later,
when needed, unregister) each lock separately.

That worked, but required hwspinlocks drivers to do a bit extra work
when they were probed/removed.

This patch changes hwspin_lock_{un}register() to allow a bank of
hwspinlocks to be {un}registered in a single invocation.

A new 'struct hwspinlock_device', which contains an array of 'struct
hwspinlock's is now being passed to the core upon registration (so
instead of wrapping each struct hwspinlock, a priv member has been added
to allow drivers to piggyback their private data with each hwspinlock).

While at it, several per-lock members were moved to be per-device:
1. struct device *dev
2. struct hwspinlock_ops *ops

In addition, now that the array of locks is handled by the core,
there's no reason to maintain a per-lock 'int id' member: the id of the
lock anyway equals to its index in the bank's array plus the bank's
base_id.
Remove this per-lock id member too, and instead use a simple pointers
arithmetic to derive it.

As a result of this change, hwspinlocks drivers are now simpler and smaller
(about %20 code reduction) and the memory footprint of the hwspinlock
framework is reduced.

Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>

hwspinlock/core/omap: fix id issues on multiple hwspinlock devices

hwspinlock devices provide system-wide hardware locks that are used
by remote processors that have no other way to achieve synchronization.

To achieve that, each physical lock must have a system-wide id number
that is agreed upon, otherwise remote processors can't possibly assume
they're using the same hardware lock.

Usually boards have a single hwspinlock device, which provides several
hwspinlocks, and in this case, they can be trivially numbered 0 to
(num-of-locks - 1).

In case boards have several hwspinlocks devices, a different base id
should be used for each hwspinlock device (they can't all use 0 as
a starting id!).

While this is certainly not common, it's just plain wrong to just
silently use 0 as a base id whenever the hwspinlock driver is probed.

This patch provides a hwspinlock_pdata structure, that boards can use
to set a different base id for each of the hwspinlock devices they may
have, and demonstrates how to use it with the omap hwspinlock driver.

While we're at it, make sure the hwspinlock core prints an explicit
error message in case an hwspinlock is registered with an id number
that already exists; this will help users catch such base id issues.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Acked-by: Tony Lindgren <tony@atomide.com>

hwspinlock/omap: simplify allocation scheme

Instead of allocating every hwspinlock separately, allocate
them all in one shot.

This both simplifies the driver and helps achieving better
slab utilization.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>

hwspinlock/core: simplify 'owner' handling

Use struct device_driver's owner member instead of asking drivers to
explicitly pass the owner again.

This simplifies drivers and also save some memory, since there's no
point now in maintaining a separate owner pointer per hwspinlock.

Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>

drivers: hwspinlock: add OMAP implementation

Add hwspinlock support for the OMAP4 Hardware Spinlock device.

The Hardware Spinlock device on OMAP4 provides hardware assistance
for synchronization between the multiple processors in the system
(dual Cortex-A9, dual Cortex-M3 and a C64x+ DSP).

[ohad@wizery.com: adapt to hwspinlock framework, tidy up]
Signed-off-by: Simon Que <sque@ti.com>
Signed-off-by: Hari Kanigeri <h-kanigeri2@ti.com>
Signed-off-by: Krishnamoorthy, Balaji T <balajitk@ti.com>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Benoit Cousson <b-cousson@ti.com>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Tony Lindgren <tony@atomide.com>