Merge git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6
[pandora-kernel.git] / drivers / ieee1394 / raw1394.c
index 571ea68..5ec4f5e 100644 (file)
 #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 */