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From:   Yury Norov <yury.norov@gmail.com>
To:     linux-kernel@vger.kernel.org, Karsten Graul <kgraul@linux.ibm.com>,
        Wenjia Zhang <wenjia@linux.ibm.com>,
        Jan Karcher <jaka@linux.ibm.com>,
        "D. Wythe" <alibuda@linux.alibaba.com>,
        Tony Lu <tonylu@linux.alibaba.com>,
        Wen Gu <guwen@linux.alibaba.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, linux-s390@vger.kernel.org,
        netdev@vger.kernel.org
Cc:     Yury Norov <yury.norov@gmail.com>, Jan Kara <jack@suse.cz>,
        Mirsad Todorovac <mirsad.todorovac@alu.unizg.hr>,
        Matthew Wilcox <willy@infradead.org>,
        Rasmus Villemoes <linux@rasmusvillemoes.dk>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Maxim Kuvyrkov <maxim.kuvyrkov@linaro.org>,
        Alexey Klimov <klimov.linux@gmail.com>,
        Bart Van Assche <bvanassche@acm.org>,
        Sergey Shtylyov <s.shtylyov@omp.ru>,
        Alexandra Winter <wintera@linux.ibm.com>
Subject: [PATCH v3 31/35] net: smc: optimize smc_wr_tx_get_free_slot_index()
Date:   Mon, 11 Dec 2023 18:27:45 -0800
Message-Id: <20231212022749.625238-32-yury.norov@gmail.com>
In-Reply-To: <20231212022749.625238-1-yury.norov@gmail.com>
References: <20231212022749.625238-1-yury.norov@gmail.com>
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Simplify the function by using find_and_set_bit() and make it a simple
almost one-liner.

While here, drop explicit initialization of *idx, because it's already
initialized by the caller in case of ENOLINK, or set properly with
->wr_tx_mask, if nothing is found, in case of EBUSY.

CC: Tony Lu <tonylu@linux.alibaba.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
---
 net/smc/smc_wr.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/net/smc/smc_wr.c b/net/smc/smc_wr.c
index 0021065a600a..b6f0cfc52788 100644
--- a/net/smc/smc_wr.c
+++ b/net/smc/smc_wr.c
@@ -170,15 +170,11 @@ void smc_wr_tx_cq_handler(struct ib_cq *ib_cq, void *cq_context)
 
 static inline int smc_wr_tx_get_free_slot_index(struct smc_link *link, u32 *idx)
 {
-	*idx = link->wr_tx_cnt;
 	if (!smc_link_sendable(link))
 		return -ENOLINK;
-	for_each_clear_bit(*idx, link->wr_tx_mask, link->wr_tx_cnt) {
-		if (!test_and_set_bit(*idx, link->wr_tx_mask))
-			return 0;
-	}
-	*idx = link->wr_tx_cnt;
-	return -EBUSY;
+
+	*idx = find_and_set_bit(link->wr_tx_mask, link->wr_tx_cnt);
+	return *idx < link->wr_tx_cnt ? 0 : -EBUSY;
 }
 
 /**
-- 
2.40.1