firewire: core: code refactoring to find and pop transaction entry

The list operation to find and pop transaction entry appears several
times in transaction implementation, and can be replaced with a helper
functional macro.

Link: https://lore.kernel.org/r/20251101102131.925071-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

diff --git a/drivers/firewire/core-transaction.c b/drivers/firewire/core-transaction.c
index 8bd79c3f97f2459995d5bb88653307fbd209e6cd..e80791d6d46b90923c798bf9f6c41e4d3b662ddd 100644 (file)
--- a/drivers/firewire/core-transaction.c
+++ b/drivers/firewire/core-transaction.c
@@ -51,28 +51,34 @@ static void remove_transaction_entry(struct fw_card *card, struct fw_transaction
        card->transactions.tlabel_mask &= ~(1ULL << entry->tlabel);
 }
 
+// card->transactions.lock must be acquired in advance.
+#define find_and_pop_transaction_entry(card, condition)                        \
+({                                                                     \
+       struct fw_transaction *iter, *t = NULL;                         \
+       list_for_each_entry(iter, &card->transactions.list, link) {     \
+               if (condition) {                                        \
+                       t = iter;                                       \
+                       break;                                          \
+               }                                                       \
+       }                                                               \
+       if (t && try_cancel_split_timeout(t))                           \
+               remove_transaction_entry(card, t);                      \
+       t;                                                              \
+})
+
 static int close_transaction(struct fw_transaction *transaction, struct fw_card *card, int rcode,
                             u32 response_tstamp)
 {
-       struct fw_transaction *t = NULL, *iter;
+       struct fw_transaction *t;
 
        // NOTE: This can be without irqsave when we can guarantee that __fw_send_request() for
        // local destination never runs in any type of IRQ context.
        scoped_guard(spinlock_irqsave, &card->transactions.lock) {
-               list_for_each_entry(iter, &card->transactions.list, link) {
-                       if (iter == transaction) {
-                               if (try_cancel_split_timeout(iter)) {
-                                       remove_transaction_entry(card, iter);
-                                       t = iter;
-                               }
-                               break;
-                       }
-               }
+               t = find_and_pop_transaction_entry(card, iter == transaction);
+               if (!t)
+                       return -ENOENT;
        }
 
-       if (!t)
-               return -ENOENT;
-
        if (!t->with_tstamp) {
                t->callback.without_tstamp(card, rcode, NULL, 0, t->callback_data);
        } else {
@@ -1102,7 +1108,7 @@ EXPORT_SYMBOL(fw_core_handle_request);
 
 void fw_core_handle_response(struct fw_card *card, struct fw_packet *p)
 {
-       struct fw_transaction *t = NULL, *iter;
+       struct fw_transaction *t = NULL;
        u32 *data;
        size_t data_length;
        int tcode, tlabel, source, rcode;
@@ -1144,15 +1150,8 @@ void fw_core_handle_response(struct fw_card *card, struct fw_packet *p)
        // NOTE: This can be without irqsave when we can guarantee that __fw_send_request() for
        // local destination never runs in any type of IRQ context.
        scoped_guard(spinlock_irqsave, &card->transactions.lock) {
-               list_for_each_entry(iter, &card->transactions.list, link) {
-                       if (iter->node_id == source && iter->tlabel == tlabel) {
-                               if (try_cancel_split_timeout(iter)) {
-                                       remove_transaction_entry(card, iter);
-                                       t = iter;
-                               }
-                               break;
-                       }
-               }
+               t = find_and_pop_transaction_entry(card,
+                               iter->node_id == source && iter->tlabel == tlabel);
        }
 
        trace_async_response_inbound((uintptr_t)t, card->index, p->generation, p->speed, p->ack,