Commit 6dcdd884 authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by David S. Miller
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net: hwbm: Make the hwbm_pool lock a mutex 



Based on review, `lock' is only acquired in hwbm_pool_add() which is
invoked via ->probe(), ->resume() and ->ndo_change_mtu(). Based on this
the lock can become a mutex and there is no need to disable interrupts
during the procedure.
Now that the lock is a mutex, hwbm_pool_add() no longer invokes
hwbm_pool_refill() in an atomic context so we can pass GFP_KERNEL to
hwbm_pool_refill() and remove the `gfp' argument from hwbm_pool_add().

Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 49eef82d

drivers/net/ethernet/marvell/mvneta.c

+1 −1
Original line number Diff line number Diff line
@@ -1119,7 +1119,7 @@ static void mvneta_bm_update_mtu(struct mvneta_port *pp, int mtu) 
			SKB_DATA_ALIGN(MVNETA_RX_BUF_SIZE(bm_pool->pkt_size));



	/* Fill entire long pool */

	num = hwbm_pool_add(hwbm_pool, hwbm_pool->size, GFP_ATOMIC);

	num = hwbm_pool_add(hwbm_pool, hwbm_pool->size);

	if (num != hwbm_pool->size) {

		WARN(1, "pool %d: %d of %d allocated\n",

		     bm_pool->id, num, hwbm_pool->size);

drivers/net/ethernet/marvell/mvneta_bm.c

+2 −2
Original line number Diff line number Diff line
@@ -190,7 +190,7 @@ struct mvneta_bm_pool *mvneta_bm_pool_use(struct mvneta_bm *priv, u8 pool_id, 
			SKB_DATA_ALIGN(sizeof(struct skb_shared_info));

		hwbm_pool->construct = mvneta_bm_construct;

		hwbm_pool->priv = new_pool;

		spin_lock_init(&hwbm_pool->lock);

		mutex_init(&hwbm_pool->buf_lock);



		/* Create new pool */

		err = mvneta_bm_pool_create(priv, new_pool);
@@ -201,7 +201,7 @@ struct mvneta_bm_pool *mvneta_bm_pool_use(struct mvneta_bm *priv, u8 pool_id, 
		}



		/* Allocate buffers for this pool */

		num = hwbm_pool_add(hwbm_pool, hwbm_pool->size, GFP_ATOMIC);

		num = hwbm_pool_add(hwbm_pool, hwbm_pool->size);

		if (num != hwbm_pool->size) {

			WARN(1, "pool %d: %d of %d allocated\n",

			     new_pool->id, num, hwbm_pool->size);

include/net/hwbm.h

+3 −3
Original line number Diff line number Diff line
@@ -12,18 +12,18 @@ struct hwbm_pool { 
	/* constructor called during alocation */

	int (*construct)(struct hwbm_pool *bm_pool, void *buf);

	/* protect acces to the buffer counter*/

	spinlock_t lock;

	struct mutex buf_lock;

	/* private data */

	void *priv;

};

#ifdef CONFIG_HWBM

void hwbm_buf_free(struct hwbm_pool *bm_pool, void *buf);

int hwbm_pool_refill(struct hwbm_pool *bm_pool, gfp_t gfp);

int hwbm_pool_add(struct hwbm_pool *bm_pool, unsigned int buf_num, gfp_t gfp);

int hwbm_pool_add(struct hwbm_pool *bm_pool, unsigned int buf_num);

#else

void hwbm_buf_free(struct hwbm_pool *bm_pool, void *buf) {}

int hwbm_pool_refill(struct hwbm_pool *bm_pool, gfp_t gfp) { return 0; }

int hwbm_pool_add(struct hwbm_pool *bm_pool, unsigned int buf_num, gfp_t gfp)

int hwbm_pool_add(struct hwbm_pool *bm_pool, unsigned int buf_num)

{ return 0; }

#endif /* CONFIG_HWBM */

#endif /* _HWBM_H */

net/core/hwbm.c

+7 −8
Original line number Diff line number Diff line
@@ -43,34 +43,33 @@ int hwbm_pool_refill(struct hwbm_pool *bm_pool, gfp_t gfp) 
}

EXPORT_SYMBOL_GPL(hwbm_pool_refill);



int hwbm_pool_add(struct hwbm_pool *bm_pool, unsigned int buf_num, gfp_t gfp)

int hwbm_pool_add(struct hwbm_pool *bm_pool, unsigned int buf_num)

{

	int err, i;

	unsigned long flags;



	spin_lock_irqsave(&bm_pool->lock, flags);

	mutex_lock(&bm_pool->buf_lock);

	if (bm_pool->buf_num == bm_pool->size) {

		pr_warn("pool already filled\n");

		spin_unlock_irqrestore(&bm_pool->lock, flags);

		mutex_unlock(&bm_pool->buf_lock);

		return bm_pool->buf_num;

	}



	if (buf_num + bm_pool->buf_num > bm_pool->size) {

		pr_warn("cannot allocate %d buffers for pool\n",

			buf_num);

		spin_unlock_irqrestore(&bm_pool->lock, flags);

		mutex_unlock(&bm_pool->buf_lock);

		return 0;

	}



	if ((buf_num + bm_pool->buf_num) < bm_pool->buf_num) {

		pr_warn("Adding %d buffers to the %d current buffers will overflow\n",

			buf_num,  bm_pool->buf_num);

		spin_unlock_irqrestore(&bm_pool->lock, flags);

		mutex_unlock(&bm_pool->buf_lock);

		return 0;

	}



	for (i = 0; i < buf_num; i++) {

		err = hwbm_pool_refill(bm_pool, gfp);

		err = hwbm_pool_refill(bm_pool, GFP_KERNEL);

		if (err < 0)

			break;

	}
@@ -79,7 +78,7 @@ int hwbm_pool_add(struct hwbm_pool *bm_pool, unsigned int buf_num, gfp_t gfp) 
	bm_pool->buf_num += i;



	pr_debug("hwpm pool: %d of %d buffers added\n", i, buf_num);

	spin_unlock_irqrestore(&bm_pool->lock, flags);

	mutex_unlock(&bm_pool->buf_lock);



	return i;

}

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