33 struct ring {  struct
39 	struct ring	       *ring;  argument
47 void qxl_ring_free(struct qxl_ring *ring)  in qxl_ring_free()  argument
49 	kfree(ring);  in qxl_ring_free()
52 void qxl_ring_init_hdr(struct qxl_ring *ring)  in qxl_ring_init_hdr()  argument
54 	ring->ring->header.notify_on_prod = ring->n_elements;  in qxl_ring_init_hdr()
65 	struct qxl_ring *ring;  in qxl_ring_create()  local
67 	ring = kmalloc(sizeof(*ring), GFP_KERNEL);  in qxl_ring_create()
68 	if (!ring)  in qxl_ring_create()
71 	ring->ring = (struct ring *)header;  in qxl_ring_create()
72 	ring->element_size = element_size;  in qxl_ring_create()
73 	ring->n_elements = n_elements;  in qxl_ring_create()
74 	ring->prod_notify = prod_notify;  in qxl_ring_create()
75 	ring->push_event = push_event;  in qxl_ring_create()
77 		qxl_ring_init_hdr(ring);  in qxl_ring_create()
78 	spin_lock_init(&ring->lock);  in qxl_ring_create()
79 	return ring;  in qxl_ring_create()
82 static int qxl_check_header(struct qxl_ring *ring)  in qxl_check_header()  argument
85 	struct qxl_ring_header *header = &(ring->ring->header);  in qxl_check_header()
87 	spin_lock_irqsave(&ring->lock, flags);  in qxl_check_header()
91 	spin_unlock_irqrestore(&ring->lock, flags);  in qxl_check_header()
95 int qxl_check_idle(struct qxl_ring *ring)  in qxl_check_idle()  argument
98 	struct qxl_ring_header *header = &(ring->ring->header);  in qxl_check_idle()
100 	spin_lock_irqsave(&ring->lock, flags);  in qxl_check_idle()
102 	spin_unlock_irqrestore(&ring->lock, flags);  in qxl_check_idle()
106 int qxl_ring_push(struct qxl_ring *ring,  in qxl_ring_push()  argument
109 	struct qxl_ring_header *header = &(ring->ring->header);  in qxl_ring_push()
113 	spin_lock_irqsave(&ring->lock, flags);  in qxl_ring_push()
117 		spin_unlock_irqrestore(&ring->lock, flags);  in qxl_ring_push()
119 			while (!qxl_check_header(ring))  in qxl_ring_push()
123 				ret = wait_event_interruptible(*ring->push_event,  in qxl_ring_push()
124 							       qxl_check_header(ring));  in qxl_ring_push()
128 				wait_event(*ring->push_event,  in qxl_ring_push()
129 					   qxl_check_header(ring));  in qxl_ring_push()
133 		spin_lock_irqsave(&ring->lock, flags);  in qxl_ring_push()
136 	idx = header->prod & (ring->n_elements - 1);  in qxl_ring_push()
137 	elt = ring->ring->elements + idx * ring->element_size;  in qxl_ring_push()
139 	memcpy((void *)elt, new_elt, ring->element_size);  in qxl_ring_push()
146 		outb(0, ring->prod_notify);  in qxl_ring_push()
148 	spin_unlock_irqrestore(&ring->lock, flags);  in qxl_ring_push()
152 static bool qxl_ring_pop(struct qxl_ring *ring,  in qxl_ring_pop()  argument
155 	volatile struct qxl_ring_header *header = &(ring->ring->header);  in qxl_ring_pop()
159 	spin_lock_irqsave(&ring->lock, flags);  in qxl_ring_pop()
162 		spin_unlock_irqrestore(&ring->lock, flags);  in qxl_ring_pop()
166 	idx = header->cons & (ring->n_elements - 1);  in qxl_ring_pop()
167 	ring_elt = ring->ring->elements + idx * ring->element_size;  in qxl_ring_pop()
169 	memcpy(element, (void *)ring_elt, ring->element_size);  in qxl_ring_pop()
173 	spin_unlock_irqrestore(&ring->lock, flags);  in qxl_ring_pop()