firewire: core: use guard macro to maintain the list of card

The core function maintains registered cards by list. The concurrent
access to the list is protected by static mutex.

This commit uses guard macro to maintain the mutex.

Link: https://lore.kernel.org/r/20240805085408.251763-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

diff --git a/drivers/firewire/core-card.c b/drivers/firewire/core-card.c
index f8b99dd6cd827d67e060efc65ff603cb6ceb2860..79a5b19e9d18a4c85fd724c3f9052911c1ec931f 100644 (file)
--- a/drivers/firewire/core-card.c
+++ b/drivers/firewire/core-card.c
@@ -168,7 +168,6 @@ static size_t required_space(struct fw_descriptor *desc)
 int fw_core_add_descriptor(struct fw_descriptor *desc)
 {
        size_t i;
-       int ret;
 
        /*
         * Check descriptor is valid; the length of all blocks in the
@@ -182,29 +181,25 @@ int fw_core_add_descriptor(struct fw_descriptor *desc)
        if (i != desc->length)
                return -EINVAL;
 
-       mutex_lock(&card_mutex);
+       guard(mutex)(&card_mutex);
 
-       if (config_rom_length + required_space(desc) > 256) {
-               ret = -EBUSY;
-       } else {
-               list_add_tail(&desc->link, &descriptor_list);
-               config_rom_length += required_space(desc);
-               descriptor_count++;
-               if (desc->immediate > 0)
-                       descriptor_count++;
-               update_config_roms();
-               ret = 0;
-       }
+       if (config_rom_length + required_space(desc) > 256)
+               return -EBUSY;
 
-       mutex_unlock(&card_mutex);
+       list_add_tail(&desc->link, &descriptor_list);
+       config_rom_length += required_space(desc);
+       descriptor_count++;
+       if (desc->immediate > 0)
+               descriptor_count++;
+       update_config_roms();
 
-       return ret;
+       return 0;
 }
 EXPORT_SYMBOL(fw_core_add_descriptor);
 
 void fw_core_remove_descriptor(struct fw_descriptor *desc)
 {
-       mutex_lock(&card_mutex);
+       guard(mutex)(&card_mutex);
 
        list_del(&desc->link);
        config_rom_length -= required_space(desc);
@@ -212,8 +207,6 @@ void fw_core_remove_descriptor(struct fw_descriptor *desc)
        if (desc->immediate > 0)
                descriptor_count--;
        update_config_roms();
-
-       mutex_unlock(&card_mutex);
 }
 EXPORT_SYMBOL(fw_core_remove_descriptor);
 
@@ -587,16 +580,16 @@ int fw_card_add(struct fw_card *card,
        card->link_speed = link_speed;
        card->guid = guid;
 
-       mutex_lock(&card_mutex);
+       guard(mutex)(&card_mutex);
 
        generate_config_rom(card, tmp_config_rom);
        ret = card->driver->enable(card, tmp_config_rom, config_rom_length);
-       if (ret == 0)
-               list_add_tail(&card->link, &card_list);
+       if (ret < 0)
+               return ret;
 
-       mutex_unlock(&card_mutex);
+       list_add_tail(&card->link, &card_list);
 
-       return ret;
+       return 0;
 }
 EXPORT_SYMBOL(fw_card_add);
 
@@ -720,9 +713,8 @@ void fw_core_remove_card(struct fw_card *card)
                                     PHY_LINK_ACTIVE | PHY_CONTENDER, 0);
        fw_schedule_bus_reset(card, false, true);
 
-       mutex_lock(&card_mutex);
-       list_del_init(&card->link);
-       mutex_unlock(&card_mutex);
+       scoped_guard(mutex, &card_mutex)
+               list_del_init(&card->link);
 
        /* Switch off most of the card driver interface. */
        dummy_driver.free_iso_context   = card->driver->free_iso_context;