[PATCH v2 1/8] hpet: simplify subdirectory registration with register_sysctl()

[Luis Chamberlain]

There is no need to user boiler plate code to specify a set of base
directories we're going to stuff sysctls under. Simplify this by using
register_sysctl() and specifying the directory path directly.

// pycocci sysctl-subdir-register-sysctl-simplify.cocci drivers/char/hpet.c

@c1@
expression E1;
identifier subdir, sysctls;
@@

static struct ctl_table subdir[] = {
        {
                .procname = E1,
                .maxlen = 0,
                .mode = 0555,
                .child = sysctls,
        },
        { }
};

@c2@
identifier c1.subdir;

expression E2;
identifier base;
@@

static struct ctl_table base[] = {
        {
                .procname = E2,
                .maxlen = 0,
                .mode = 0555,
                .child = subdir,
        },
        { }
};

@c3@
identifier c2.base;
identifier header;
@@

header = register_sysctl_table(base);

@r1 depends on c1 && c2 && c3@
expression c1.E1;
identifier c1.subdir, c1.sysctls;
@@

-static struct ctl_table subdir[] = {
-       {
-               .procname = E1,
-               .maxlen = 0,
-               .mode = 0555,
-               .child = sysctls,
-       },
-       { }
-};

@r2 depends on c1 && c2 && c3@
identifier c1.subdir;

expression c2.E2;
identifier c2.base;
@@
-static struct ctl_table base[] = {
-       {
-               .procname = E2,
-               .maxlen = 0,
-               .mode = 0555,
-               .child = subdir,
-       },
-       { }
-};

@initialize:python@
@@

def make_my_fresh_expression(s1, s2):
  return '"' + s1.strip('"') + "/" + s2.strip('"') + '"'

@r3 depends on c1 && c2 && c3@
expression c1.E1;
identifier c1.sysctls;
expression c2.E2;
identifier c2.base;
identifier c3.header;
fresh identifier E3 = script:python(E2, E1) { make_my_fresh_expression(E2, E1) 
};
@@

header =
-register_sysctl_table(base);
+register_sysctl(E3, sysctls);

Generated-by: Coccinelle SmPL
Signed-off-by: Luis Chamberlain <mcg...@kernel.org>
---
 drivers/char/hpet.c | 22 +---------------------
 1 file changed, 1 insertion(+), 21 deletions(-)

diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index 4e5431f01450..563dfae3b8da 100644
--- a/drivers/char/hpet.c
+++ b/drivers/char/hpet.c
@@ -746,26 +746,6 @@ static struct ctl_table hpet_table[] = {
        {}
 };
 
-static struct ctl_table hpet_root[] = {
-       {
-        .procname = "hpet",
-        .maxlen = 0,
-        .mode = 0555,
-        .child = hpet_table,
-        },
-       {}
-};
-
-static struct ctl_table dev_root[] = {
-       {
-        .procname = "dev",
-        .maxlen = 0,
-        .mode = 0555,
-        .child = hpet_root,
-        },
-       {}
-};
-
 static struct ctl_table_header *sysctl_header;
 
 /*
@@ -1061,7 +1041,7 @@ static int __init hpet_init(void)
        if (result < 0)
                return -ENODEV;
 
-       sysctl_header = register_sysctl_table(dev_root);
+       sysctl_header = register_sysctl("dev/hpet", hpet_table);
 
        result = acpi_bus_register_driver(&hpet_acpi_driver);
        if (result < 0) {
-- 
2.33.0