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| author | Julian Wiedmann <jwi@linux.ibm.com> | 2020-03-25 10:35:00 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-03-25 12:07:15 -0700 |
| commit | 0a6e634535f1b47b00501c0b563a827eb1f8ec8c (patch) | |
| tree | b446647da95f0981b672f570df362b09f66bc9d8 /arch/s390 | |
| parent | b439044b70e4b7992f82974eb77d92c95da5960f (diff) | |
| download | linux-0a6e634535f1b47b00501c0b563a827eb1f8ec8c.tar.gz linux-0a6e634535f1b47b00501c0b563a827eb1f8ec8c.tar.bz2 linux-0a6e634535f1b47b00501c0b563a827eb1f8ec8c.zip | |
s390/qdio: extend polling support to multiple queues
When the support for polling drivers was initially added, it only
considered Input Queue 0. But as QDIO interrupts are actually for the
full device and not a single queue, this doesn't really fit for
configurations where multiple Input Queues are used.
Rework the qdio code so that interrupts for a polling driver are not
split up into actions for each queue. Instead deliver the interrupt as
a single event, and let the driver decide which queue needs what action.
When re-enabling the QDIO interrupt via qdio_start_irq(), this means
that the qdio code needs to
(1) put _all_ eligible queues back into a state where they raise IRQs,
(2) and afterwards check _all_ eligible queues for new work to bridge
the race window.
On the qeth side of things (as the only qdio polling driver), we can now
add CQ polling support to the main NAPI poll routine. It doesn't consume
NAPI budget, and to avoid hogging the CPU we yield control after
completing one full queue worth of buffers.
The subsequent qdio_start_irq() will check for any additional work, and
have us re-schedule the NAPI instance accordingly.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/include/asm/qdio.h | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/arch/s390/include/asm/qdio.h b/arch/s390/include/asm/qdio.h index 1e3517b0518b..e577f8533009 100644 --- a/arch/s390/include/asm/qdio.h +++ b/arch/s390/include/asm/qdio.h @@ -338,7 +338,7 @@ typedef void qdio_handler_t(struct ccw_device *, unsigned int, int, * @no_output_qs: number of output queues * @input_handler: handler to be called for input queues * @output_handler: handler to be called for output queues - * @queue_start_poll_array: polling handlers (one per input queue or NULL) + * @irq_poll: Data IRQ polling handler (NULL when not supported) * @scan_threshold: # of in-use buffers that triggers scan on output queue * @int_parm: interruption parameter * @input_sbal_addr_array: address of no_input_qs * 128 pointers @@ -359,8 +359,7 @@ struct qdio_initialize { unsigned int no_output_qs; qdio_handler_t *input_handler; qdio_handler_t *output_handler; - void (**queue_start_poll_array) (struct ccw_device *, int, - unsigned long); + void (*irq_poll)(struct ccw_device *cdev, unsigned long data); unsigned int scan_threshold; unsigned long int_parm; struct qdio_buffer **input_sbal_addr_array; @@ -415,8 +414,8 @@ extern int qdio_activate(struct ccw_device *); extern void qdio_release_aob(struct qaob *); extern int do_QDIO(struct ccw_device *, unsigned int, int, unsigned int, unsigned int); -extern int qdio_start_irq(struct ccw_device *, int); -extern int qdio_stop_irq(struct ccw_device *, int); +extern int qdio_start_irq(struct ccw_device *cdev); +extern int qdio_stop_irq(struct ccw_device *cdev); extern int qdio_get_next_buffers(struct ccw_device *, int, int *, int *); extern int qdio_inspect_queue(struct ccw_device *cdev, unsigned int nr, bool is_input, unsigned int *bufnr, |