github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-11-07 06:17:02 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

firewire: core: use appropriate spinlock variants for transaction-related locks

Browse Source 
The spinlocks in the fw_card structure protect transaction-related state
from concurrent access. They are acquired mostly from process context.
The exceptions are split_transaction_timeout_callback(), which runs in
softirq context for the timer wheel, and __fw_send_request(), which may
also be called from interrupt context.

Use spin_lock() in split_transaction_timeout_callback() and
spin_lock_irqsave() in the other functions. The latter preserves and
restores the caller's interrupt state, as the callers are not guaranteed
to have interrupts enabled.

Link: https://lore.kernel.org/r/20261012015739.530731-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
This commit is contained in:
Takashi Sakamoto 2026-10-12 10:57:39 +09:00
parent aea8c084cb
commit a78c645379
1 changed files with 2 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
drivers/firewire/core-transaction.c
View File

@ -78,8 +78,6 @@ __must_not_hold(&card->transactions.lock)
lockdep_assert_not_held(&card->transactions.lock);
// 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_safe(t, tmp, &card->transactions.list, link) {
if (try_cancel_split_timeout(t))
@ -140,9 +138,6 @@ __must_not_hold(&card->transactions.lock)
// If the request packet has already been sent, we need to see if the transaction is still
// pending and remove it in that case (e.g. the split transaction).
//
// 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) {
if (!find_and_pop_transaction_entry(card, iter == transaction))
return -ENOENT;
@ -184,7 +179,7 @@ static void split_transaction_timeout_callback(struct timer_list *timer)
lockdep_assert_not_held(&card->transactions.lock);
scoped_guard(spinlock_irqsave, &card->transactions.lock) {
scoped_guard(spinlock, &card->transactions.lock) {
if (list_empty(&t->link))
return;
remove_transaction_entry(card, t);
@ -227,14 +222,12 @@ __must_not_hold(&card->transactions.lock)
{
unsigned int delta;
scoped_guard(spinlock, &card->split_timeout.lock) {
scoped_guard(spinlock_irqsave, &card->split_timeout.lock) {
t->split_timeout_cycle =
compute_split_timeout_timestamp(card, packet->timestamp) & 0xffff;
delta = card->split_timeout.jiffies;
}
// 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)
start_split_transaction_timeout(t, delta);
return;
@ -259,8 +252,6 @@ __must_not_hold(&card->transactions.lock)
break;
}
// 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) {
if (!find_and_pop_transaction_entry(card, iter == t))
return;
@ -431,8 +422,6 @@ __must_not_hold(&card->transactions.lock)
* the list while holding the card spinlock.
*/
// 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)
tlabel = allocate_tlabel(card);
if (tlabel < 0) {
@ -458,15 +447,11 @@ __must_not_hold(&card->transactions.lock)
// The node_id field of fw_card can be updated when handling SelfIDComplete.
int node_id;
// 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->lock)
node_id = card->node_id;
fw_fill_request(&t->packet, tcode, t->tlabel, destination_id, node_id, generation, speed,
offset, payload, length);
// 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_add_tail(&t->link, &card->transactions.list);
@ -1232,8 +1217,6 @@ __must_not_hold(&card->transactions.lock)
break;
}
// 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) {
t = find_and_pop_transaction_entry(card,
iter->node_id == source && iter->tlabel == tlabel);