[PATCH] kernel-doc: add support for ____cacheline_aligned attribute

[PATCH] kernel-doc: add support for ____cacheline_aligned attribute

[Jonathan Cameron]

From: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Subroutine dump_struct uses type attributes to check if the struct
syntax is valid. Then, it removes all attributes before using it for
output. `____cacheline_aligned` is an attribute that is
not included in both steps. Add it, since it is used by kernel structs.

Based on previous patch to add ____cacheline_aligned_in_smp.
Motivated by patches to reorder this attribute to before the
variable name.   Whilst we could do that in all cases, that would
be a massive change and it is more common in the kernel to place
this particular attribute after the variable name. A quick grep
suggests approximately 400 instances of which 341 have this
attribute just before a semicolon and hence after the variable name.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Lee Jones <lee.jones@linaro.org>
---

Note I haven't figured out what this is actually doing and hence the
patch is done by copying the changes made for ____cacheline_aligned_in_smp.
It seems to work. :)

 scripts/kernel-doc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/scripts/kernel-doc b/scripts/kernel-doc
index d1b445665ad6..cc55e1c2a8a4 100755
--- a/scripts/kernel-doc
+++ b/scripts/kernel-doc
@@ -1083,7 +1083,7 @@ sub dump_struct($$) {
     my $x = shift;
     my $file = shift;
 
-    if ($x =~ /(struct|union)\s+(\w+)\s*\{(.*)\}(\s*(__packed|__aligned|____cacheline_aligned_in_smp|__attribute__\s*\(\([a-z0-9,_\s\(\)]*\)\)))*/) {
+    if ($x =~ /(struct|union)\s+(\w+)\s*\{(.*)\}(\s*(__packed|__aligned|____cacheline_aligned_in_smp|____cacheline_aligned|__attribute__\s*\(\([a-z0-9,_\s\(\)]*\)\)))*/) {
 	my $decl_type = $1;
 	$declaration_name = $2;
 	my $members = $3;
@@ -1099,6 +1099,7 @@ sub dump_struct($$) {
 	$members =~ s/\s*__packed\s*/ /gos;
 	$members =~ s/\s*CRYPTO_MINALIGN_ATTR/ /gos;
 	$members =~ s/\s*____cacheline_aligned_in_smp/ /gos;
+	$members =~ s/\s*____cacheline_aligned/ /gos;
 
 	# replace DECLARE_BITMAP
 	$members =~ s/__ETHTOOL_DECLARE_LINK_MODE_MASK\s*\(([^\)]+)\)/DECLARE_BITMAP($1, __ETHTOOL_LINK_MODE_MASK_NBITS)/gos;
-- 
2.28.0

Re: [PATCH] kernel-doc: add support for ____cacheline_aligned attribute

[Jonathan Corbet]

On Thu, 10 Sep 2020 19:54:15 +0100
Jonathan Cameron <jic23@kernel.org> wrote:

> Subroutine dump_struct uses type attributes to check if the struct
> syntax is valid. Then, it removes all attributes before using it for
> output. `____cacheline_aligned` is an attribute that is
> not included in both steps. Add it, since it is used by kernel structs.
> 
> Based on previous patch to add ____cacheline_aligned_in_smp.
> Motivated by patches to reorder this attribute to before the
> variable name.   Whilst we could do that in all cases, that would
> be a massive change and it is more common in the kernel to place
> this particular attribute after the variable name. A quick grep
> suggests approximately 400 instances of which 341 have this
> attribute just before a semicolon and hence after the variable name.
> 
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Cc: Lee Jones <lee.jones@linaro.org>
> ---
> 
> Note I haven't figured out what this is actually doing and hence the
> patch is done by copying the changes made for ____cacheline_aligned_in_smp.
> It seems to work. :)

The little secret is that *nobody* really understands what all the regexes
in kernel-doc do :)  Anyway, it does indeed seem to work; applied, thanks.

jon