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ionic: use index not pointer for queue tracking

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Use index counters rather than pointers for tracking head
and tail in the queues to save a little memory and to perhaps
slightly faster queue processing.

Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Shannon Nelson 2020-08-27 16:00:26 -07:00 • committed by David S. Miller
parent ea5a8b09dc
commit f1d2e894f1
7 changed files with 129 additions and 88 deletions
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40
drivers/net/ethernet/pensando/ionic/ionic_dev.c
View file

@ -482,7 +482,7 @@ int ionic_cq_init(struct ionic_lif *lif, struct ionic_cq *cq,
cq->bound_intr = intr;
cq->num_descs = num_descs;
cq->desc_size = desc_size;
cq->tail = cq->info;
cq->tail_idx = 0;
cq->done_color = 1;
cur = cq->info;
@ -522,15 +522,18 @@ unsigned int ionic_cq_service(struct ionic_cq *cq, unsigned int work_to_do,
ionic_cq_cb cb, ionic_cq_done_cb done_cb,
void *done_arg)
{
struct ionic_cq_info *cq_info;
unsigned int work_done = 0;
if (work_to_do == 0)
return 0;
while (cb(cq, cq->tail)) {
if (cq->tail->last)
cq_info = &cq->info[cq->tail_idx];
while (cb(cq, cq_info)) {
if (cq->tail_idx == cq->num_descs - 1)
cq->done_color = !cq->done_color;
cq->tail = cq->tail->next;
cq->tail_idx = (cq->tail_idx + 1) & (cq->num_descs - 1);
cq_info = &cq->info[cq->tail_idx];
DEBUG_STATS_CQE_CNT(cq);
if (++work_done >= work_to_do)
@ -565,8 +568,8 @@ int ionic_q_init(struct ionic_lif *lif, struct ionic_dev *idev,
q->num_descs = num_descs;
q->desc_size = desc_size;
q->sg_desc_size = sg_desc_size;
q->tail = q->info;
q->head = q->tail;
q->tail_idx = 0;
q->head_idx = 0;
q->pid = pid;
snprintf(q->name, sizeof(q->name), "L%d-%s%u", lif->index, name, index);
@ -614,19 +617,22 @@ void ionic_q_post(struct ionic_queue *q, bool ring_doorbell, ionic_desc_cb cb,
void *cb_arg)
{
struct device *dev = q->lif->ionic->dev;
struct ionic_desc_info *desc_info;
struct ionic_lif *lif = q->lif;
q->head->cb = cb;
q->head->cb_arg = cb_arg;
q->head = q->head->next;
desc_info = &q->info[q->head_idx];
desc_info->cb = cb;
desc_info->cb_arg = cb_arg;
q->head_idx = (q->head_idx + 1) & (q->num_descs - 1);
dev_dbg(dev, "lif=%d qname=%s qid=%d qtype=%d p_index=%d ringdb=%d\n",
q->lif->index, q->name, q->hw_type, q->hw_index,
q->head->index, ring_doorbell);
q->head_idx, ring_doorbell);
if (ring_doorbell)
ionic_dbell_ring(lif->kern_dbpage, q->hw_type,
q->dbval | q->head->index);
q->dbval | q->head_idx);
}
static bool ionic_q_is_posted(struct ionic_queue *q, unsigned int pos)
@ -634,8 +640,8 @@ static bool ionic_q_is_posted(struct ionic_queue *q, unsigned int pos)
unsigned int mask, tail, head;
mask = q->num_descs - 1;
tail = q->tail->index;
head = q->head->index;
tail = q->tail_idx;
head = q->head_idx;
return ((pos - tail) & mask) < ((head - tail) & mask);
}
@ -648,18 +654,18 @@ void ionic_q_service(struct ionic_queue *q, struct ionic_cq_info *cq_info,
void *cb_arg;
/* check for empty queue */
if (q->tail->index == q->head->index)
if (q->tail_idx == q->head_idx)
return;
/* stop index must be for a descriptor that is not yet completed */
if (unlikely(!ionic_q_is_posted(q, stop_index)))
dev_err(q->lif->ionic->dev,
"ionic stop is not posted %s stop %u tail %u head %u\n",
q->name, stop_index, q->tail->index, q->head->index);
q->name, stop_index, q->tail_idx, q->head_idx);
do {
desc_info = q->tail;
q->tail = desc_info->next;
desc_info = &q->info[q->tail_idx];
q->tail_idx = (q->tail_idx + 1) & (q->num_descs - 1);
cb = desc_info->cb;
cb_arg = desc_info->cb_arg;