Commit ecd68ef8 authored by Christophe JAILLET's avatar Christophe JAILLET Committed by Jason Gunthorpe
Browse files

RDMA/pvrdma: Use non-atomic bitmap functions when possible 

In 'pvrdma_uar_table_init()', the 'tbl->table' bitmap has just been
allocated, so no concurrent accesses can occur.

The other accesses to the 'tbl->table' bitmap are protected by the
'tbl->lock' spinlock, so no concurrent accesses can happen.

So prefer the non-atomic '__[set|clear]_bit()' functions to save a few
cycles.

Link: https://lore.kernel.org/r/271b0e2c316e2b4cf34ac6fbca0701edd2d882ec.1637870667.git.christophe.jaillet@wanadoo.fr


Signed-off-by: default avatarChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent 67ec0fdf

drivers/infiniband/hw/vmw_pvrdma/pvrdma_doorbell.c

+3 −3
Original line number Diff line number Diff line
@@ -68,7 +68,7 @@ int pvrdma_uar_table_init(struct pvrdma_dev *dev) 
		return -ENOMEM;



	/* 0th UAR is taken by the device. */

	set_bit(0, tbl->table);

	__set_bit(0, tbl->table);



	return 0;

}
@@ -100,7 +100,7 @@ int pvrdma_uar_alloc(struct pvrdma_dev *dev, struct pvrdma_uar_map *uar) 
		return -ENOMEM;

	}



	set_bit(obj, tbl->table);

	__set_bit(obj, tbl->table);

	obj |= tbl->top;



	spin_unlock_irqrestore(&tbl->lock, flags);
@@ -120,7 +120,7 @@ void pvrdma_uar_free(struct pvrdma_dev *dev, struct pvrdma_uar_map *uar) 


	obj = uar->index & (tbl->max - 1);

	spin_lock_irqsave(&tbl->lock, flags);

	clear_bit(obj, tbl->table);

	__clear_bit(obj, tbl->table);

	tbl->last = min(tbl->last, obj);

	tbl->top = (tbl->top + tbl->max) & tbl->mask;

	spin_unlock_irqrestore(&tbl->lock, flags);