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firewire: ohci: use workqueue to handle events of AT request/response contexts

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This commit adds a work item to handle events of 1394 OHCI AT
request/response contexts, and queues the item to the specific
workqueue. The call of struct fw_packet.callbaqck() is done in the
workqueue when receiving acknowledgement to the asynchronous packet
transferred to remote node.

Link: https://lore.kernel.org/r/20250615133253.433057-4-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
This commit is contained in:
Takashi Sakamoto 2025-06-15 22:32:53 +09:00
parent 57e6d9f85f
commit aef6bcc0f2
3 changed files with 35 additions and 20 deletions
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4
drivers/firewire/net.c
View file

@ -1007,7 +1007,7 @@ static int fwnet_send_packet(struct fwnet_packet_task *ptask)
spin_lock_irqsave(&dev->lock, flags); spin_lock_irqsave(&dev->lock, flags);
/* If the AT tasklet already ran, we may be last user. */ /* If the AT work item already ran, we may be last user. */
free = (ptask->outstanding_pkts == 0 && !ptask->enqueued); free = (ptask->outstanding_pkts == 0 && !ptask->enqueued);
if (!free) if (!free)
ptask->enqueued = true; ptask->enqueued = true;
@ -1026,7 +1026,7 @@ static int fwnet_send_packet(struct fwnet_packet_task *ptask)
spin_lock_irqsave(&dev->lock, flags); spin_lock_irqsave(&dev->lock, flags);
/* If the AT tasklet already ran, we may be last user. */ /* If the AT work item already ran, we may be last user. */
free = (ptask->outstanding_pkts == 0 && !ptask->enqueued); free = (ptask->outstanding_pkts == 0 && !ptask->enqueued);
if (!free) if (!free)
ptask->enqueued = true; ptask->enqueued = true;

40
drivers/firewire/ohci.c
View file

@ -158,7 +158,7 @@ struct context {
descriptor_callback_t callback; descriptor_callback_t callback;
struct tasklet_struct tasklet; struct work_struct work;
}; };
struct iso_context { struct iso_context {
@ -1176,9 +1176,9 @@ static void context_retire_descriptors(struct context *ctx)
} }
} }
static void context_tasklet(unsigned long data) static void ohci_at_context_work(struct work_struct *work)
{ {
struct context *ctx = (struct context *) data; struct context *ctx = from_work(ctx, work, work);
context_retire_descriptors(ctx); context_retire_descriptors(ctx);
} }
@ -1243,7 +1243,6 @@ static int context_init(struct context *ctx, struct fw_ohci *ohci,
ctx->buffer_tail = list_entry(ctx->buffer_list.next, ctx->buffer_tail = list_entry(ctx->buffer_list.next,
struct descriptor_buffer, list); struct descriptor_buffer, list);
tasklet_init(&ctx->tasklet, context_tasklet, (unsigned long)ctx);
ctx->callback = callback; ctx->callback = callback;
/* /*
@ -1524,13 +1523,17 @@ static int at_context_queue_packet(struct context *ctx,
static void at_context_flush(struct context *ctx) static void at_context_flush(struct context *ctx)
{ {
tasklet_disable(&ctx->tasklet); // Avoid dead lock due to programming mistake.
if (WARN_ON_ONCE(current_work() == &ctx->work))
return;
ctx->flushing = true; disable_work_sync(&ctx->work);
context_tasklet((unsigned long)ctx);
ctx->flushing = false;
tasklet_enable(&ctx->tasklet); WRITE_ONCE(ctx->flushing, true);
ohci_at_context_work(&ctx->work);
WRITE_ONCE(ctx->flushing, false);
enable_work(&ctx->work);
} }
static int handle_at_packet(struct context *context, static int handle_at_packet(struct context *context,
@ -1542,7 +1545,7 @@ static int handle_at_packet(struct context *context,
struct fw_ohci *ohci = context->ohci; struct fw_ohci *ohci = context->ohci;
int evt; int evt;
if (last->transfer_status == 0 && !context->flushing) if (last->transfer_status == 0 && !READ_ONCE(context->flushing))
/* This descriptor isn't done yet, stop iteration. */ /* This descriptor isn't done yet, stop iteration. */
return 0; return 0;
@ -1576,7 +1579,7 @@ static int handle_at_packet(struct context *context,
break; break;
case OHCI1394_evt_missing_ack: case OHCI1394_evt_missing_ack:
if (context->flushing) if (READ_ONCE(context->flushing))
packet->ack = RCODE_GENERATION; packet->ack = RCODE_GENERATION;
else { else {
/* /*
@ -1598,7 +1601,7 @@ static int handle_at_packet(struct context *context,
break; break;
case OHCI1394_evt_no_status: case OHCI1394_evt_no_status:
if (context->flushing) { if (READ_ONCE(context->flushing)) {
packet->ack = RCODE_GENERATION; packet->ack = RCODE_GENERATION;
break; break;
} }
@ -2239,10 +2242,10 @@ static irqreturn_t irq_handler(int irq, void *data)
queue_work(ohci->card.async_wq, &ohci->ar_response_ctx.work); queue_work(ohci->card.async_wq, &ohci->ar_response_ctx.work);
if (event & OHCI1394_reqTxComplete) if (event & OHCI1394_reqTxComplete)
tasklet_schedule(&ohci->at_request_ctx.tasklet); queue_work(ohci->card.async_wq, &ohci->at_request_ctx.work);
if (event & OHCI1394_respTxComplete) if (event & OHCI1394_respTxComplete)
tasklet_schedule(&ohci->at_response_ctx.tasklet); queue_work(ohci->card.async_wq, &ohci->at_response_ctx.work);
if (event & OHCI1394_isochRx) { if (event & OHCI1394_isochRx) {
iso_event = reg_read(ohci, OHCI1394_IsoRecvIntEventClear); iso_event = reg_read(ohci, OHCI1394_IsoRecvIntEventClear);
@ -2684,7 +2687,10 @@ static int ohci_cancel_packet(struct fw_card *card, struct fw_packet *packet)
struct driver_data *driver_data = packet->driver_data; struct driver_data *driver_data = packet->driver_data;
int ret = -ENOENT; int ret = -ENOENT;
tasklet_disable_in_atomic(&ctx->tasklet); // Avoid dead lock due to programming mistake.
if (WARN_ON_ONCE(current_work() == &ctx->work))
return 0;
disable_work_sync(&ctx->work);
if (packet->ack != 0) if (packet->ack != 0)
goto out; goto out;
@ -2703,7 +2709,7 @@ static int ohci_cancel_packet(struct fw_card *card, struct fw_packet *packet)
packet->callback(packet, &ohci->card, packet->ack); packet->callback(packet, &ohci->card, packet->ack);
ret = 0; ret = 0;
out: out:
tasklet_enable(&ctx->tasklet); enable_work(&ctx->work);
return ret; return ret;
} }
@ -3765,11 +3771,13 @@ static int pci_probe(struct pci_dev *dev,
OHCI1394_AsReqTrContextControlSet, handle_at_packet); OHCI1394_AsReqTrContextControlSet, handle_at_packet);
if (err < 0) if (err < 0)
return err; return err;
INIT_WORK(&ohci->at_request_ctx.work, ohci_at_context_work);
err = context_init(&ohci->at_response_ctx, ohci, err = context_init(&ohci->at_response_ctx, ohci,
OHCI1394_AsRspTrContextControlSet, handle_at_packet); OHCI1394_AsRspTrContextControlSet, handle_at_packet);
if (err < 0) if (err < 0)
return err; return err;
INIT_WORK(&ohci->at_response_ctx.work, ohci_at_context_work);
reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, ~0); reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, ~0);
ohci->ir_context_channels = ~0ULL; ohci->ir_context_channels = ~0ULL;

11
include/linux/firewire.h
View file

@ -308,8 +308,7 @@ struct fw_packet {
* For successful transmission, the status code is the ack received * For successful transmission, the status code is the ack received
* from the destination. Otherwise it is one of the juju-specific * from the destination. Otherwise it is one of the juju-specific
* rcodes: RCODE_SEND_ERROR, _CANCELLED, _BUSY, _GENERATION, _NO_ACK. * rcodes: RCODE_SEND_ERROR, _CANCELLED, _BUSY, _GENERATION, _NO_ACK.
* The callback can be called from tasklet context and thus * The callback can be called from workqueue and thus must never block.
* must never block.
*/ */
fw_packet_callback_t callback; fw_packet_callback_t callback;
int ack; int ack;
@ -382,6 +381,10 @@ void __fw_send_request(struct fw_card *card, struct fw_transaction *t, int tcode
* *
* A variation of __fw_send_request() to generate callback for response subaction without time * A variation of __fw_send_request() to generate callback for response subaction without time
* stamp. * stamp.
*
* The callback is invoked in the workqueue context in most cases. However, if an error is detected
* before queueing or the destination address refers to the local node, it is invoked in the
* current context instead.
*/ */
static inline void fw_send_request(struct fw_card *card, struct fw_transaction *t, int tcode, static inline void fw_send_request(struct fw_card *card, struct fw_transaction *t, int tcode,
int destination_id, int generation, int speed, int destination_id, int generation, int speed,
@ -411,6 +414,10 @@ static inline void fw_send_request(struct fw_card *card, struct fw_transaction *
* @callback_data: data to be passed to the transaction completion callback * @callback_data: data to be passed to the transaction completion callback
* *
* A variation of __fw_send_request() to generate callback for response subaction with time stamp. * A variation of __fw_send_request() to generate callback for response subaction with time stamp.
*
* The callback is invoked in the workqueue context in most cases. However, if an error is detected
* before queueing or the destination address refers to the local node, it is invoked in the current
* context instead.
*/ */
static inline void fw_send_request_with_tstamp(struct fw_card *card, struct fw_transaction *t, static inline void fw_send_request_with_tstamp(struct fw_card *card, struct fw_transaction *t,
int tcode, int destination_id, int generation, int speed, unsigned long long offset, int tcode, int destination_id, int generation, int speed, unsigned long long offset,