The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Reviewed-by: Baolin Wang <baolin.wang7@gmail.com>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20200319213839.GA10669@embeddedor.com
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Since the hwspinlock core has changed the PM runtime to be optional, thus
remove the redundant PM runtime implementation in the u8500 HWSEM driver.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Since the hwspinlock core has changed the PM runtime to be optional, thus
remove the redundant PM runtime implementation in the Spreadtrum hwlock
driver.
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Now some hwspinlock controllers did not have the requirement to implement
the PM runtime, but drivers must enable the PM runtime to comply with the
hwspinlock core.
Thus we can change the PM runtime support to be optional by validating
the -EACCES error number which means the PM runtime is not enabled, and
removing the return value validating of pm_runtime_put(). So that we
can remove some redundant PM runtime code in drivers.
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
The original code use BUG_ON() to validate the parameters when locking
or unlocking one hardware lock, but we should not crash the whole kernel
though the hwlock parameters are incorrect, instead we can return
the error number for users and give some warning.
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Use devm_hwspin_lock_register() to register the hwlock controller instead of
unregistering the hwlock controller explicitly when removing the device.
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Use devm_add_action_or_reset() for calls to clk_disable_unprepare(),
which can simplify the error handling.
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
We must check the return value of clk_prepare_enable() to make sure the
hardware spinlock controller can be enabled successfully, otherwise we
should return error.
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Use the new helper that wraps the calls to platform_get_resource()
and devm_ioremap_resource() together, which can simpify the code.
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Use devm_hwspin_lock_register() to register the hwlock controller instead of
unregistering the hwlock controller explicitly when removing the device.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Use the new helper that wraps the calls to platform_get_resource()
and devm_ioremap_resource() together, which can simpify the code.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Add the 'in_atomic' mode which can be called from an atomic context.
This mode relies on the existing 'raw' mode (no lock, no preemption/irq
disabling) with the difference that the timeout is not based on jiffies
(jiffies won't increase when irq are disabled) but handled with
busy-waiting udelay() calls.
Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Implement this optional ops, called by hwspinlock core while spinning on
a lock, between two successive invocations of trylock().
Reviewed-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
