From 87045fbb8083abb9d77e4874ce5d431b2cdd7ef3 Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Fri, 14 Aug 2026 14:19:16 +0300 Subject: thunderbolt: Allow batching of descriptors The hardware allows queueing descriptors ahead of updating producer/consumer fields. This way it is possible to avoid unnecessary register writes on hot-paths such as when transferring networking packets. For this reason introduce an API that allows Thunderbolt service drivers to opt-in for this and take advantage of batching. Assisted-by: LLM Signed-off-by: Mika Westerberg --- include/linux/thunderbolt.h | 42 +++++++++++++++++++++++++++++++++++++++--- 1 file changed, 39 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/thunderbolt.h b/include/linux/thunderbolt.h index d48623fda79b..6fda5596c44b 100644 --- a/include/linux/thunderbolt.h +++ b/include/linux/thunderbolt.h @@ -552,6 +552,8 @@ struct tb_nhi { * @work: Interrupt work structure * @is_tx: Is the ring Tx or Rx * @running: Is the ring running + * @notify_pending: Controller has not been notified about the posted + * descriptors yet * @irq: MSI-X irq number if the ring uses MSI-X. %0 otherwise. * @vector: MSI-X vector number the ring uses (only set if @irq is > 0) * @flags: Ring specific flags @@ -580,6 +582,7 @@ struct tb_ring { struct work_struct work; bool is_tx:1; bool running:1; + bool notify_pending:1; int irq; u8 vector; unsigned int flags; @@ -669,7 +672,8 @@ bool tb_ring_flush(struct tb_ring *ring, unsigned int timeout_msec); void tb_ring_stop(struct tb_ring *ring); void tb_ring_free(struct tb_ring *ring); -int __tb_ring_enqueue(struct tb_ring *ring, struct ring_frame *frame); +int __tb_ring_enqueue(struct tb_ring *ring, struct ring_frame *frame, bool more); +void tb_ring_notify(struct tb_ring *ring); /** * tb_ring_rx() - enqueue a frame on an RX ring @@ -690,7 +694,24 @@ int __tb_ring_enqueue(struct tb_ring *ring, struct ring_frame *frame); static inline int tb_ring_rx(struct tb_ring *ring, struct ring_frame *frame) { WARN_ON(ring->is_tx); - return __tb_ring_enqueue(ring, frame); + return __tb_ring_enqueue(ring, frame, false); +} + +/** + * tb_ring_rx_more() - enqueue a frame on an RX ring without notifying + * @ring: Ring to enqueue the frame + * @frame: Frame to enqueue + * + * Same as tb_ring_rx() but does not notify the controller about the + * enqueued frame. The caller must call tb_ring_notify() once it is done + * enqueuing frames. + * + * Return: %-ESHUTDOWN if tb_ring_stop() has been called, %0 otherwise. + */ +static inline int tb_ring_rx_more(struct tb_ring *ring, struct ring_frame *frame) +{ + WARN_ON(ring->is_tx); + return __tb_ring_enqueue(ring, frame, true); } /** @@ -711,7 +732,22 @@ static inline int tb_ring_rx(struct tb_ring *ring, struct ring_frame *frame) static inline int tb_ring_tx(struct tb_ring *ring, struct ring_frame *frame) { WARN_ON(!ring->is_tx); - return __tb_ring_enqueue(ring, frame); + return __tb_ring_enqueue(ring, frame, false); +} + +/** + * tb_ring_tx_more() - enqueue a frame on a TX ring without notifying + * @ring: Ring to enqueue the frame + * @frame: Frame to enqueue + * + * Same as tb_ring_rx_more() but for TX ring. + * + * Return: %-ESHUTDOWN if tb_ring_stop() has been called, %0 otherwise. + */ +static inline int tb_ring_tx_more(struct tb_ring *ring, struct ring_frame *frame) +{ + WARN_ON(!ring->is_tx); + return __tb_ring_enqueue(ring, frame, true); } /* Used only when the ring is in polling mode */ -- cgit v1.2.3