Re: [PATCH] Rename DECLARE_MUTEX to DEFINE_SEMAPHORE

Marcin Slusarz
2008-10-26T15:27:11Z

On Sun, Oct 26, 2008 at 02:39:06PM +0100, Peter Zijlstra wrote:
> On Sun, 2008-10-26 at 13:06 +0100, Marcin Slusarz wrote:
> > DECLARE_MUTEX is doubly misleading name (it actually _defines_ struct
> > _semaphore_ initialized to 1) and it can be confused with DEFINE_MUTEX
> > (which defines real struct mutex). Rename it.
>
> I'd prefer DEFINE_BINARY_SEM or somesuch

Sounds better.

---
Subject: [PATCH] Rename DECLARE_MUTEX to DEFINE_BINARY_SEM

DECLARE_MUTEX is doubly misleading name (it actually _defines_ struct
_semaphore_ initialized to 1) and it can be confused with DEFINE_MUTEX
(which defines real struct mutex). Rename it.

Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
---
arch/arm/mach-lh7a40x/clocks.c | 2 +-
drivers/macintosh/adb.c | 2 +-
drivers/staging/go7007/go7007-i2c.c | 4 ++--
include/linux/semaphore.h | 5 +++--
kernel/printk.c | 4 ++--
lib/dynamic_printk.c | 2 +-
scripts/checkpatch.pl | 2 +-
sound/soc/s3c24xx/s3c2443-ac97.c | 2 +-
8 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/arch/arm/mach-lh7a40x/clocks.c b/arch/arm/mach-lh7a40x/clocks.c
index 4fb23ac..de27e81 100644
--- a/arch/arm/mach-lh7a40x/clocks.c
+++ b/arch/arm/mach-lh7a40x/clocks.c
@@ -80,7 +80,7 @@ unsigned int pclkfreq_get (void)
/* ----- */

static LIST_HEAD(clocks);
-static DECLARE_MUTEX(clocks_sem);
+static DEFINE_BINARY_SEM(clocks_sem);

struct clk *clk_get (struct device *dev, const char *id)
{
diff --git a/drivers/macintosh/adb.c b/drivers/macintosh/adb.c
index 23741ce..7cf07c2 100644
--- a/drivers/macintosh/adb.c
+++ b/drivers/macintosh/adb.c
@@ -83,7 +83,7 @@ static struct adb_driver *adb_controller;
BLOCKING_NOTIFIER_HEAD(adb_client_list);
static int adb_got_sleep;
static int adb_inited;
-static DECLARE_MUTEX(adb_probe_mutex);
+static DEFINE_BINARY_SEM(adb_probe_mutex);
static int sleepy_trackpad;
static int autopoll_devs;
int __adb_probe_sync;
diff --git a/drivers/staging/go7007/go7007-i2c.c b/drivers/staging/go7007/go7007-i2c.c
index cd55b76..6f698af 100644
--- a/drivers/staging/go7007/go7007-i2c.c
+++ b/drivers/staging/go7007/go7007-i2c.c
@@ -56,7 +56,7 @@ struct wis_i2c_client_driver {
};

static LIST_HEAD(i2c_client_drivers);
-static DECLARE_MUTEX(i2c_client_driver_list_lock);
+static DEFINE_BINARY_SEM(i2c_client_driver_list_lock);

/* Client drivers register here by their I2C driver ID */
int wis_i2c_add_driver(unsigned int id, found_proc found_proc)
@@ -129,7 +129,7 @@ int wis_i2c_probe_device(struct i2c_adapter *adapter,

/* There is only one I2C port on the TW2804 that feeds all four GO7007 VIPs
* on the Adlink PCI-MPG24, so access is shared between all of them. */
-static DECLARE_MUTEX(adlink_mpg24_i2c_lock);
+static DEFINE_BINARY_SEM(adlink_mpg24_i2c_lock);

static int go7007_i2c_xfer(struct go7007 *go, u16 addr, int read,
u16 command, int flags, u8 *data)
diff --git a/include/linux/semaphore.h b/include/linux/semaphore.h
index 7415839..824b423 100644
--- a/include/linux/semaphore.h
+++ b/include/linux/semaphore.h
@@ -26,8 +26,9 @@ struct semaphore {
.wait_list = LIST_HEAD_INIT((name).wait_list), \
}

-#define DECLARE_MUTEX(name) \
- struct semaphore name = __SEMAPHORE_INITIALIZER(name, 1)
+#define DEFINE_SEMAPHORE(name, init) \
+ struct semaphore name = __SEMAPHORE_INITIALIZER(name, init)
+#define DEFINE_BINARY_SEM(name) DEFINE_SEMAPHORE(name, 1)

static inline void sema_init(struct semaphore *sem, int val)
{
diff --git a/kernel/printk.c b/kernel/printk.c
index 6341af7..2a2281b 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -72,8 +72,8 @@ EXPORT_SYMBOL(oops_in_progress);
* provides serialisation for access to the entire console
* driver system.
*/
-static DECLARE_MUTEX(console_sem);
-static DECLARE_MUTEX(secondary_console_sem);
+static DEFINE_BINARY_SEM(console_sem);
+static DEFINE_BINARY_SEM(secondary_console_sem);
struct console *console_drivers;
EXPORT_SYMBOL_GPL(console_drivers);

diff --git a/lib/dynamic_printk.c b/lib/dynamic_printk.c
index d640f87..0b3dbdb 100644
--- a/lib/dynamic_printk.c
+++ b/lib/dynamic_printk.c
@@ -34,7 +34,7 @@ static struct hlist_head module_table[DEBUG_HASH_TABLE_SIZE] =
{ [0 ... DEBUG_HASH_TABLE_SIZE-1] = HLIST_HEAD_INIT };
static struct hlist_head module_table2[DEBUG_HASH_TABLE_SIZE] =
{ [0 ... DEBUG_HASH_TABLE_SIZE-1] = HLIST_HEAD_INIT };
-static DECLARE_MUTEX(debug_list_mutex);
+static DEFINE_BINARY_SEM(debug_list_mutex);

/* dynamic_printk_enabled, and dynamic_printk_enabled2 are bitmasks in which
* bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index f88bb3e..91462b0 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2428,7 +2428,7 @@ sub process {
}

# check for semaphores used as mutexes
- if ($line =~ /^.\s*(DECLARE_MUTEX|init_MUTEX)\s*\(/) {
+ if ($line =~ /^.\s*(DEFINE_BINARY_SEM|init_MUTEX)\s*\(/) {
WARN("mutexes are preferred for single holder semaphores\n" . $herecurr);
}
# check for semaphores used as mutexes
diff --git a/sound/soc/s3c24xx/s3c2443-ac97.c b/sound/soc/s3c24xx/s3c2443-ac97.c
index 19c5c3c..8980111 100644
--- a/sound/soc/s3c24xx/s3c2443-ac97.c
+++ b/sound/soc/s3c24xx/s3c2443-ac97.c
@@ -46,7 +46,7 @@ static struct s3c24xx_ac97_info s3c24xx_ac97;

static DECLARE_COMPLETION(ac97_completion);
static u32 codec_ready;
-static DECLARE_MUTEX(ac97_mutex);
+static DEFINE_BINARY_SEM(ac97_mutex);

static unsigned short s3c2443_ac97_read(struct snd_ac97 *ac97,
unsigned short reg)
--
1.5.6.4