Commit Graph

4 Commits

Author SHA1 Message Date
Gustavo A. R. Silva 6a8785082c dmaengine: uniphier-mdmac: replace zero-length array with flexible-array member
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")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20200213003535.GA3269@embeddedor.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-02-13 20:15:57 +05:30
Masahiro Yamada 5b3e3606ab dmaengine: uniphier-mdmac: use devm_platform_ioremap_resource()
Replace the chain of platform_get_resource() and devm_ioremap_resource()
with devm_platform_ioremap_resource().

This allows to remove the local variable for (struct resource *), and
have one function call less.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Link: https://lore.kernel.org/r/20190905034133.29514-1-yamada.masahiro@socionext.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2019-10-11 15:45:41 +05:30
Stephen Boyd e17be6e1b7 dmaengine: Remove dev_err() usage after platform_get_irq()
We don't need dev_err() messages when platform_get_irq() fails now that
platform_get_irq() prints an error message itself when something goes
wrong. Let's remove these prints with a simple semantic patch.

// <smpl>
@@
expression ret;
struct platform_device *E;
@@

ret =
(
platform_get_irq(E, ...)
|
platform_get_irq_byname(E, ...)
);

if ( \( ret < 0 \| ret <= 0 \) )
{
(
-if (ret != -EPROBE_DEFER)
-{ ...
-dev_err(...);
-... }
|
...
-dev_err(...);
)
...
}
// </smpl>

While we're here, remove braces on if statements that only have one
statement (manually).

Cc: Vinod Koul <vkoul@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: dmaengine@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20190730181557.90391-11-swboyd@chromium.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2019-07-31 20:50:53 +05:30
Masahiro Yamada 32e74aabeb dmaengine: uniphier-mdmac: add UniPhier MIO DMAC driver
The MIO DMAC (Media IO DMA Controller) is used in UniPhier LD4,
Pro4, and sLD8 SoCs.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2018-11-24 19:42:59 +05:30