pcmcia: add locking to set_mem_map()

Protect the pccard_operations callback "set_mem_map" by a new
mutex ops_mutex. This mutex also protects the following values
in struct pcmcia_socket:

        pccard_mem_map          win[]
        pccard_mem_map          cis_mem
        void __iomem            *cis_virt

Tested-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

drivers/pcmcia/cistpl.c

@@ -64,6 +64,7 @@ module_param(cis_width, int, 0444);
 
 void release_cis_mem(struct pcmcia_socket *s)
 {
+    mutex_lock(&s->ops_mutex);
     if (s->cis_mem.flags & MAP_ACTIVE) {
 	s->cis_mem.flags &= ~MAP_ACTIVE;
 	s->ops->set_mem_map(s, &s->cis_mem);
@@ -75,6 +76,7 @@ void release_cis_mem(struct pcmcia_socket *s)
 	iounmap(s->cis_virt);
 	s->cis_virt = NULL;
     }
+    mutex_unlock(&s->ops_mutex);
 }
 
 /*
@@ -88,11 +90,13 @@ set_cis_map(struct pcmcia_socket *s, unsigned int card_offset, unsigned int flag
 	pccard_mem_map *mem = &s->cis_mem;
 	int ret;
 
+	mutex_lock(&s->ops_mutex);
 	if (!(s->features & SS_CAP_STATIC_MAP) && (mem->res == NULL)) {
 		mem->res = pcmcia_find_mem_region(0, s->map_size, s->map_size, 0, s);
 		if (mem->res == NULL) {
 			dev_printk(KERN_NOTICE, &s->dev,
 				   "cs: unable to map card memory!\n");
+			mutex_unlock(&s->ops_mutex);
 			return NULL;
 		}
 		s->cis_virt = NULL;
@@ -108,6 +112,7 @@ set_cis_map(struct pcmcia_socket *s, unsigned int card_offset, unsigned int flag
 	if (ret) {
 		iounmap(s->cis_virt);
 		s->cis_virt = NULL;
+		mutex_unlock(&s->ops_mutex);
 		return NULL;
 	}
 
@@ -117,6 +122,7 @@ set_cis_map(struct pcmcia_socket *s, unsigned int card_offset, unsigned int flag
 		s->cis_virt = ioremap(mem->static_start, s->map_size);
 	}
 
+	mutex_unlock(&s->ops_mutex);
 	return s->cis_virt;
 }
 

drivers/pcmcia/cs.c

@@ -222,6 +222,7 @@ int pcmcia_register_socket(struct pcmcia_socket *socket)
 	init_completion(&socket->socket_released);
 	init_completion(&socket->thread_done);
 	mutex_init(&socket->skt_mutex);
+	mutex_init(&socket->ops_mutex);
 	spin_lock_init(&socket->thread_lock);
 
 	if (socket->resource_ops->init) {

drivers/pcmcia/pcmcia_resource.c

@@ -223,6 +223,7 @@ int pcmcia_map_mem_page(struct pcmcia_device *p_dev, window_handle_t wh,
 			memreq_t *req)
 {
 	struct pcmcia_socket *s = p_dev->socket;
+	int ret;
 
 	wh--;
 	if (wh >= MAX_WIN)
@@ -231,12 +232,13 @@ int pcmcia_map_mem_page(struct pcmcia_device *p_dev, window_handle_t wh,
 		dev_dbg(&s->dev, "failure: requested page is zero\n");
 		return -EINVAL;
 	}
+	mutex_lock(&s->ops_mutex);
 	s->win[wh].card_start = req->CardOffset;
-	if (s->ops->set_mem_map(s, &s->win[wh]) != 0) {
-		dev_dbg(&s->dev, "failed to set_mem_map\n");
-		return -EIO;
-	}
-	return 0;
+	ret = s->ops->set_mem_map(s, &s->win[wh]);
+	if (ret)
+		dev_warn(&s->dev, "failed to set_mem_map\n");
+	mutex_unlock(&s->ops_mutex);
+	return ret;
 } /* pcmcia_map_mem_page */
 EXPORT_SYMBOL(pcmcia_map_mem_page);
 
@@ -437,10 +439,12 @@ int pcmcia_release_window(struct pcmcia_device *p_dev, window_handle_t wh)
 	if (wh >= MAX_WIN)
 		return -EINVAL;
 
+	mutex_lock(&s->ops_mutex);
 	win = &s->win[wh];
 
 	if (!(p_dev->_win & CLIENT_WIN_REQ(wh))) {
 		dev_dbg(&s->dev, "not releasing unknown window\n");
+		mutex_unlock(&s->ops_mutex);
 		return -EINVAL;
 	}
 
@@ -456,6 +460,7 @@ int pcmcia_release_window(struct pcmcia_device *p_dev, window_handle_t wh)
 		win->res = NULL;
 	}
 	p_dev->_win &= ~CLIENT_WIN_REQ(wh);
+	mutex_unlock(&s->ops_mutex);
 
 	return 0;
 } /* pcmcia_release_window */
@@ -829,6 +834,7 @@ int pcmcia_request_window(struct pcmcia_device *p_dev, win_req_t *req, window_ha
 		return -EINVAL;
 	}
 
+	mutex_lock(&s->ops_mutex);
 	win = &s->win[w];
 
 	if (!(s->features & SS_CAP_STATIC_MAP)) {
@@ -836,6 +842,7 @@ int pcmcia_request_window(struct pcmcia_device *p_dev, win_req_t *req, window_ha
 						      (req->Attributes & WIN_MAP_BELOW_1MB), s);
 		if (!win->res) {
 			dev_dbg(&s->dev, "allocating mem region failed\n");
+			mutex_unlock(&s->ops_mutex);
 			return -EINVAL;
 		}
 	}
@@ -854,8 +861,10 @@ int pcmcia_request_window(struct pcmcia_device *p_dev, win_req_t *req, window_ha
 	if (req->Attributes & WIN_USE_WAIT)
 		win->flags |= MAP_USE_WAIT;
 	win->card_start = 0;
+
 	if (s->ops->set_mem_map(s, win) != 0) {
 		dev_dbg(&s->dev, "failed to set memory mapping\n");
+		mutex_unlock(&s->ops_mutex);
 		return -EIO;
 	}
 	s->state |= SOCKET_WIN_REQ(w);
@@ -866,6 +875,7 @@ int pcmcia_request_window(struct pcmcia_device *p_dev, win_req_t *req, window_ha
 	else
 		req->Base = win->res->start;
 
+	mutex_unlock(&s->ops_mutex);
 	*wh = w + 1;
 
 	return 0;

drivers/pcmcia/rsrc_nonstatic.c

@@ -274,17 +274,21 @@ static int readable(struct pcmcia_socket *s, struct resource *res,
 {
 	int ret = -EINVAL;
 
+	mutex_lock(&s->ops_mutex);
 	s->cis_mem.res = res;
 	s->cis_virt = ioremap(res->start, s->map_size);
 	if (s->cis_virt) {
+		mutex_unlock(&s->ops_mutex);
 		/* as we're only called from pcmcia.c, we're safe */
 		if (s->callback->validate)
 			ret = s->callback->validate(s, count);
 		/* invalidate mapping */
+		mutex_lock(&s->ops_mutex);
 		iounmap(s->cis_virt);
 		s->cis_virt = NULL;
 	}
 	s->cis_mem.res = NULL;
+	mutex_unlock(&s->ops_mutex);
 	if ((ret) || (*count == 0))
 		return -EINVAL;
 	return 0;
@@ -300,6 +304,8 @@ static int checksum(struct pcmcia_socket *s, struct resource *res,
 	int i, a = 0, b = -1, d;
 	void __iomem *virt;
 
+	mutex_lock(&s->ops_mutex);
+
 	virt = ioremap(res->start, s->map_size);
 	if (virt) {
 		map.map = 0;
@@ -322,6 +328,8 @@ static int checksum(struct pcmcia_socket *s, struct resource *res,
 		iounmap(virt);
 	}
 
+	mutex_unlock(&s->ops_mutex);
+
 	if (b == -1)
 		return -EINVAL;
 

include/pcmcia/ss.h

@@ -203,6 +203,8 @@ struct pcmcia_socket {
 	unsigned int			thread_events;
 	/* protects socket h/w state */
 	struct mutex			skt_mutex;
+	/* protects PCMCIA state */
+	struct mutex			ops_mutex;
 	/* protects thread_events */
 	spinlock_t			thread_lock;