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path: root/drivers/ieee1394/raw1394.c
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Diffstat (limited to 'drivers/ieee1394/raw1394.c')
-rw-r--r--drivers/ieee1394/raw1394.c138
1 files changed, 80 insertions, 58 deletions
diff --git a/drivers/ieee1394/raw1394.c b/drivers/ieee1394/raw1394.c
index 571ea68c0cf2..5ec4f5eb6b19 100644
--- a/drivers/ieee1394/raw1394.c
+++ b/drivers/ieee1394/raw1394.c
@@ -44,14 +44,15 @@
#include <linux/compat.h>
#include "csr1212.h"
+#include "highlevel.h"
+#include "hosts.h"
#include "ieee1394.h"
-#include "ieee1394_types.h"
#include "ieee1394_core.h"
-#include "nodemgr.h"
-#include "hosts.h"
-#include "highlevel.h"
-#include "iso.h"
+#include "ieee1394_hotplug.h"
#include "ieee1394_transactions.h"
+#include "ieee1394_types.h"
+#include "iso.h"
+#include "nodemgr.h"
#include "raw1394.h"
#include "raw1394-private.h"
@@ -66,7 +67,7 @@
#define DBGMSG(fmt, args...) \
printk(KERN_INFO "raw1394:" fmt "\n" , ## args)
#else
-#define DBGMSG(fmt, args...)
+#define DBGMSG(fmt, args...) do {} while (0)
#endif
static LIST_HEAD(host_info_list);
@@ -132,10 +133,9 @@ static void free_pending_request(struct pending_request *req)
static void __queue_complete_req(struct pending_request *req)
{
struct file_info *fi = req->file_info;
- list_move_tail(&req->list, &fi->req_complete);
- up(&fi->complete_sem);
- wake_up_interruptible(&fi->poll_wait_complete);
+ list_move_tail(&req->list, &fi->req_complete);
+ wake_up(&fi->wait_complete);
}
static void queue_complete_req(struct pending_request *req)
@@ -463,13 +463,36 @@ raw1394_compat_read(const char __user *buf, struct raw1394_request *r)
#endif
+/* get next completed request (caller must hold fi->reqlists_lock) */
+static inline struct pending_request *__next_complete_req(struct file_info *fi)
+{
+ struct list_head *lh;
+ struct pending_request *req = NULL;
+
+ if (!list_empty(&fi->req_complete)) {
+ lh = fi->req_complete.next;
+ list_del(lh);
+ req = list_entry(lh, struct pending_request, list);
+ }
+ return req;
+}
+
+/* atomically get next completed request */
+static struct pending_request *next_complete_req(struct file_info *fi)
+{
+ unsigned long flags;
+ struct pending_request *req;
+
+ spin_lock_irqsave(&fi->reqlists_lock, flags);
+ req = __next_complete_req(fi);
+ spin_unlock_irqrestore(&fi->reqlists_lock, flags);
+ return req;
+}
static ssize_t raw1394_read(struct file *file, char __user * buffer,
size_t count, loff_t * offset_is_ignored)
{
- unsigned long flags;
struct file_info *fi = (struct file_info *)file->private_data;
- struct list_head *lh;
struct pending_request *req;
ssize_t ret;
@@ -487,22 +510,21 @@ static ssize_t raw1394_read(struct file *file, char __user * buffer,
}
if (file->f_flags & O_NONBLOCK) {
- if (down_trylock(&fi->complete_sem)) {
+ if (!(req = next_complete_req(fi)))
return -EAGAIN;
- }
} else {
- if (down_interruptible(&fi->complete_sem)) {
+ /*
+ * NB: We call the macro wait_event_interruptible() with a
+ * condition argument with side effect. This is only possible
+ * because the side effect does not occur until the condition
+ * became true, and wait_event_interruptible() won't evaluate
+ * the condition again after that.
+ */
+ if (wait_event_interruptible(fi->wait_complete,
+ (req = next_complete_req(fi))))
return -ERESTARTSYS;
- }
}
- spin_lock_irqsave(&fi->reqlists_lock, flags);
- lh = fi->req_complete.next;
- list_del(lh);
- spin_unlock_irqrestore(&fi->reqlists_lock, flags);
-
- req = list_entry(lh, struct pending_request, list);
-
if (req->req.length) {
if (copy_to_user(int2ptr(req->req.recvb), req->data,
req->req.length)) {
@@ -1752,6 +1774,7 @@ static int arm_register(struct file_info *fi, struct pending_request *req)
addr->notification_options |= addr->client_transactions;
addr->recvb = req->req.recvb;
addr->rec_length = (u16) ((req->req.misc >> 16) & 0xFFFF);
+
spin_lock_irqsave(&host_info_lock, flags);
hi = find_host_info(fi->host);
same_host = 0;
@@ -1777,9 +1800,9 @@ static int arm_register(struct file_info *fi, struct pending_request *req)
}
if (same_host) {
/* addressrange occupied by same host */
+ spin_unlock_irqrestore(&host_info_lock, flags);
vfree(addr->addr_space_buffer);
kfree(addr);
- spin_unlock_irqrestore(&host_info_lock, flags);
return (-EALREADY);
}
/* another host with valid address-entry containing same addressrange */
@@ -1807,6 +1830,8 @@ static int arm_register(struct file_info *fi, struct pending_request *req)
}
}
}
+ spin_unlock_irqrestore(&host_info_lock, flags);
+
if (another_host) {
DBGMSG("another hosts entry is valid -> SUCCESS");
if (copy_to_user(int2ptr(req->req.recvb),
@@ -1815,11 +1840,11 @@ static int arm_register(struct file_info *fi, struct pending_request *req)
" address-range-entry is invalid -> EFAULT !!!\n");
vfree(addr->addr_space_buffer);
kfree(addr);
- spin_unlock_irqrestore(&host_info_lock, flags);
return (-EFAULT);
}
free_pending_request(req); /* immediate success or fail */
/* INSERT ENTRY */
+ spin_lock_irqsave(&host_info_lock, flags);
list_add_tail(&addr->addr_list, &fi->addr_list);
spin_unlock_irqrestore(&host_info_lock, flags);
return sizeof(struct raw1394_request);
@@ -1830,15 +1855,15 @@ static int arm_register(struct file_info *fi, struct pending_request *req)
req->req.address + req->req.length);
if (retval) {
/* INSERT ENTRY */
+ spin_lock_irqsave(&host_info_lock, flags);
list_add_tail(&addr->addr_list, &fi->addr_list);
+ spin_unlock_irqrestore(&host_info_lock, flags);
} else {
DBGMSG("arm_register failed errno: %d \n", retval);
vfree(addr->addr_space_buffer);
kfree(addr);
- spin_unlock_irqrestore(&host_info_lock, flags);
return (-EALREADY);
}
- spin_unlock_irqrestore(&host_info_lock, flags);
free_pending_request(req); /* immediate success or fail */
return sizeof(struct raw1394_request);
}
@@ -1904,10 +1929,10 @@ static int arm_unregister(struct file_info *fi, struct pending_request *req)
if (another_host) {
DBGMSG("delete entry from list -> success");
list_del(&addr->addr_list);
+ spin_unlock_irqrestore(&host_info_lock, flags);
vfree(addr->addr_space_buffer);
kfree(addr);
free_pending_request(req); /* immediate success or fail */
- spin_unlock_irqrestore(&host_info_lock, flags);
return sizeof(struct raw1394_request);
}
retval =
@@ -1949,23 +1974,19 @@ static int arm_get_buf(struct file_info *fi, struct pending_request *req)
(arm_addr->end > req->req.address)) {
if (req->req.address + req->req.length <= arm_addr->end) {
offset = req->req.address - arm_addr->start;
+ spin_unlock_irqrestore(&host_info_lock, flags);
DBGMSG
("arm_get_buf copy_to_user( %08X, %p, %u )",
(u32) req->req.recvb,
arm_addr->addr_space_buffer + offset,
(u32) req->req.length);
-
if (copy_to_user
(int2ptr(req->req.recvb),
arm_addr->addr_space_buffer + offset,
- req->req.length)) {
- spin_unlock_irqrestore(&host_info_lock,
- flags);
+ req->req.length))
return (-EFAULT);
- }
- spin_unlock_irqrestore(&host_info_lock, flags);
/* We have to free the request, because we
* queue no response, and therefore nobody
* will free it. */
@@ -2005,24 +2026,23 @@ static int arm_set_buf(struct file_info *fi, struct pending_request *req)
(arm_addr->end > req->req.address)) {
if (req->req.address + req->req.length <= arm_addr->end) {
offset = req->req.address - arm_addr->start;
+ spin_unlock_irqrestore(&host_info_lock, flags);
DBGMSG
("arm_set_buf copy_from_user( %p, %08X, %u )",
arm_addr->addr_space_buffer + offset,
(u32) req->req.sendb,
(u32) req->req.length);
-
if (copy_from_user
(arm_addr->addr_space_buffer + offset,
int2ptr(req->req.sendb),
- req->req.length)) {
- spin_unlock_irqrestore(&host_info_lock,
- flags);
+ req->req.length))
return (-EFAULT);
- }
- spin_unlock_irqrestore(&host_info_lock, flags);
- free_pending_request(req); /* we have to free the request, because we queue no response, and therefore nobody will free it */
+ /* We have to free the request, because we
+ * queue no response, and therefore nobody
+ * will free it. */
+ free_pending_request(req);
return sizeof(struct raw1394_request);
} else {
DBGMSG("arm_set_buf request exceeded mapping");
@@ -2744,7 +2764,7 @@ static unsigned int raw1394_poll(struct file *file, poll_table * pt)
unsigned int mask = POLLOUT | POLLWRNORM;
unsigned long flags;
- poll_wait(file, &fi->poll_wait_complete, pt);
+ poll_wait(file, &fi->wait_complete, pt);
spin_lock_irqsave(&fi->reqlists_lock, flags);
if (!list_empty(&fi->req_complete)) {
@@ -2769,9 +2789,8 @@ static int raw1394_open(struct inode *inode, struct file *file)
fi->state = opened;
INIT_LIST_HEAD(&fi->req_pending);
INIT_LIST_HEAD(&fi->req_complete);
- sema_init(&fi->complete_sem, 0);
spin_lock_init(&fi->reqlists_lock);
- init_waitqueue_head(&fi->poll_wait_complete);
+ init_waitqueue_head(&fi->wait_complete);
INIT_LIST_HEAD(&fi->addr_list);
file->private_data = fi;
@@ -2784,7 +2803,7 @@ static int raw1394_release(struct inode *inode, struct file *file)
struct file_info *fi = file->private_data;
struct list_head *lh;
struct pending_request *req;
- int done = 0, i, fail = 0;
+ int i, fail;
int retval = 0;
struct list_head *entry;
struct arm_addr *addr = NULL;
@@ -2864,25 +2883,28 @@ static int raw1394_release(struct inode *inode, struct file *file)
"error(s) occurred \n");
}
- while (!done) {
+ for (;;) {
+ /* This locked section guarantees that neither
+ * complete nor pending requests exist once i!=0 */
spin_lock_irqsave(&fi->reqlists_lock, flags);
-
- while (!list_empty(&fi->req_complete)) {
- lh = fi->req_complete.next;
- list_del(lh);
-
- req = list_entry(lh, struct pending_request, list);
-
+ while ((req = __next_complete_req(fi)))
free_pending_request(req);
- }
-
- if (list_empty(&fi->req_pending))
- done = 1;
+ i = list_empty(&fi->req_pending);
spin_unlock_irqrestore(&fi->reqlists_lock, flags);
- if (!done)
- down_interruptible(&fi->complete_sem);
+ if (i)
+ break;
+ /*
+ * Sleep until more requests can be freed.
+ *
+ * NB: We call the macro wait_event() with a condition argument
+ * with side effect. This is only possible because the side
+ * effect does not occur until the condition became true, and
+ * wait_event() won't evaluate the condition again after that.
+ */
+ wait_event(fi->wait_complete, (req = next_complete_req(fi)));
+ free_pending_request(req);
}
/* Remove any sub-trees left by user space programs */