From a15af54f8f2a32d629781417503843bfbd02a004 Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Tue, 4 Oct 2016 11:25:50 +1100 Subject: [PATCH] net/ncsi: Rework request index allocation The NCSI request index (struct ncsi_request::id) is put into instance ID (IID) field while sending NCSI command packet. It was designed the available IDs are given in round-robin fashion. @ndp->request_id was introduced to represent the next available ID, but it has been used as number of successively allocated IDs. It breaks the round-robin design. Besides, we shouldn't put 0 to NCSI command packet's IID field, meaning ID#0 should be reserved according section 6.3.1.1 in NCSI spec (v1.1.0). This fixes above two issues. With it applied, the available IDs will be assigned in round-robin fashion and ID#0 won't be assigned. Signed-off-by: Gavin Shan Reviewed-by: Joel Stanley Signed-off-by: David S. Miller --- net/ncsi/internal.h | 1 + net/ncsi/ncsi-manage.c | 17 +++++++++-------- 2 files changed, 10 insertions(+), 8 deletions(-) diff --git a/net/ncsi/internal.h b/net/ncsi/internal.h index 66dc851d49ee..c956fe8d80c3 100644 --- a/net/ncsi/internal.h +++ b/net/ncsi/internal.h @@ -259,6 +259,7 @@ struct ncsi_dev_priv { struct list_head packages; /* List of packages */ struct ncsi_request requests[256]; /* Request table */ unsigned int request_id; /* Last used request ID */ +#define NCSI_REQ_START_IDX 1 unsigned int pending_req_num; /* Number of pending requests */ struct ncsi_package *active_package; /* Currently handled package */ struct ncsi_channel *active_channel; /* Currently handled channel */ diff --git a/net/ncsi/ncsi-manage.c b/net/ncsi/ncsi-manage.c index 8c5e0160d578..00ce2c7fdb15 100644 --- a/net/ncsi/ncsi-manage.c +++ b/net/ncsi/ncsi-manage.c @@ -427,30 +427,31 @@ struct ncsi_request *ncsi_alloc_request(struct ncsi_dev_priv *ndp, bool driven) /* Check if there is one available request until the ceiling */ spin_lock_irqsave(&ndp->lock, flags); - for (i = ndp->request_id; !nr && i < limit; i++) { + for (i = ndp->request_id; i < limit; i++) { if (ndp->requests[i].used) continue; nr = &ndp->requests[i]; nr->used = true; nr->driven = driven; - if (++ndp->request_id >= limit) - ndp->request_id = 0; + ndp->request_id = i + 1; + goto found; } /* Fail back to check from the starting cursor */ - for (i = 0; !nr && i < ndp->request_id; i++) { + for (i = NCSI_REQ_START_IDX; i < ndp->request_id; i++) { if (ndp->requests[i].used) continue; nr = &ndp->requests[i]; nr->used = true; nr->driven = driven; - if (++ndp->request_id >= limit) - ndp->request_id = 0; + ndp->request_id = i + 1; + goto found; } - spin_unlock_irqrestore(&ndp->lock, flags); +found: + spin_unlock_irqrestore(&ndp->lock, flags); return nr; } @@ -1148,7 +1149,7 @@ struct ncsi_dev *ncsi_register_dev(struct net_device *dev, /* Initialize private NCSI device */ spin_lock_init(&ndp->lock); INIT_LIST_HEAD(&ndp->packages); - ndp->request_id = 0; + ndp->request_id = NCSI_REQ_START_IDX; for (i = 0; i < ARRAY_SIZE(ndp->requests); i++) { ndp->requests[i].id = i; ndp->requests[i].ndp = ndp; -- 2.20.1