Commit 313dc689 authored by Julian Wiedmann's avatar Julian Wiedmann Committed by David S. Miller
Browse files

s390/qdio: let drivers opt-out from Output Queue scanning 



If a driver wants to use the new Output Queue poll code, then the qdio
layer must disable its internal Queue scanning. Let the driver select
this mode by passing a special scan_threshold of 0.

As the scan_threshold is the same for all Output Queues, also move it
into the main qdio_irq struct. This allows for fast opt-out checking, a
driver is expected to operate either _all_ or none of its Output Queues
in polling mode.

Signed-off-by: default avatarJulian Wiedmann <jwi@linux.ibm.com>
Acked-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7c47f5af

arch/s390/include/asm/qdio.h

+1 −1
Original line number Diff line number Diff line
@@ -359,7 +359,7 @@ struct qdio_initialize { 
	qdio_handler_t *output_handler;

	void (**queue_start_poll_array) (struct ccw_device *, int,

					  unsigned long);

	int scan_threshold;

	unsigned int scan_threshold;

	unsigned long int_parm;

	struct qdio_buffer **input_sbal_addr_array;

	struct qdio_buffer **output_sbal_addr_array;

drivers/s390/cio/qdio.h

+1 −2
Original line number Diff line number Diff line
@@ -206,8 +206,6 @@ struct qdio_output_q { 
	struct qdio_outbuf_state *sbal_state;

	/* timer to check for more outbound work */

	struct timer_list timer;

	/* used SBALs before tasklet schedule */

	int scan_threshold;

};



/*
@@ -295,6 +293,7 @@ struct qdio_irq { 
	struct qdio_ssqd_desc ssqd_desc;

	void (*orig_handler) (struct ccw_device *, unsigned long, struct irb *);



	unsigned int scan_threshold;	/* used SBALs before tasklet schedule */

	int perf_stat_enabled;



	struct qdr *qdr;

drivers/s390/cio/qdio_main.c

+8 −3
Original line number Diff line number Diff line
@@ -880,7 +880,7 @@ static inline void qdio_check_outbound_pci_queues(struct qdio_irq *irq) 
	struct qdio_q *out;

	int i;



	if (!pci_out_supported(irq))

	if (!pci_out_supported(irq) || !irq->scan_threshold)

		return;



	for_each_output_queue(irq, out, i)
@@ -973,7 +973,7 @@ static void qdio_int_handler_pci(struct qdio_irq *irq_ptr) 
		}

	}



	if (!pci_out_supported(irq_ptr))

	if (!pci_out_supported(irq_ptr) || !irq_ptr->scan_threshold)

		return;



	for_each_output_queue(irq_ptr, q, i) {
@@ -1528,6 +1528,7 @@ set: 
static int handle_outbound(struct qdio_q *q, unsigned int callflags,

			   int bufnr, int count)

{

	const unsigned int scan_threshold = q->irq_ptr->scan_threshold;

	unsigned char state = 0;

	int used, rc = 0;
@@ -1566,8 +1567,12 @@ static int handle_outbound(struct qdio_q *q, unsigned int callflags, 
		rc = qdio_kick_outbound_q(q, 0);

	}



	/* Let drivers implement their own completion scanning: */

	if (!scan_threshold)

		return rc;



	/* in case of SIGA errors we must process the error immediately */

	if (used >= q->u.out.scan_threshold || rc)

	if (used >= scan_threshold || rc)

		qdio_tasklet_schedule(q);

	else

		/* free the SBALs in case of no further traffic */

drivers/s390/cio/qdio_setup.c

+1 −1
Original line number Diff line number Diff line
@@ -248,7 +248,6 @@ static void setup_queues(struct qdio_irq *irq_ptr, 
		output_sbal_state_array += QDIO_MAX_BUFFERS_PER_Q;



		q->is_input_q = 0;

		q->u.out.scan_threshold = qdio_init->scan_threshold;

		setup_storage_lists(q, irq_ptr, output_sbal_array, i);

		output_sbal_array += QDIO_MAX_BUFFERS_PER_Q;
@@ -474,6 +473,7 @@ int qdio_setup_irq(struct qdio_initialize *init_data) 
	irq_ptr->nr_input_qs = init_data->no_input_qs;

	irq_ptr->nr_output_qs = init_data->no_output_qs;

	irq_ptr->cdev = init_data->cdev;

	irq_ptr->scan_threshold = init_data->scan_threshold;

	ccw_device_get_schid(irq_ptr->cdev, &irq_ptr->schid);

	setup_queues(irq_ptr, init_data);

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