V4L/DVB (3306): Fixed i2c return value, conversion mdelay to msleep
[powerpc.git] / drivers / usb / gadget / file_storage.c
index ea09aaa..de59c58 100644 (file)
 #include <linux/fs.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
+#include <linux/kref.h>
 #include <linux/kthread.h>
 #include <linux/limits.h>
 #include <linux/list.h>
 #include <linux/string.h>
 #include <linux/suspend.h>
 #include <linux/utsname.h>
-#include <linux/wait.h>
 
 #include <linux/usb_ch9.h>
 #include <linux/usb_gadget.h>
 
 #define DRIVER_DESC            "File-backed Storage Gadget"
 #define DRIVER_NAME            "g_file_storage"
-#define DRIVER_VERSION         "20 October 2004"
+#define DRIVER_VERSION         "28 November 2005"
 
 static const char longname[] = DRIVER_DESC;
 static const char shortname[] = DRIVER_NAME;
@@ -335,8 +335,8 @@ MODULE_LICENSE("Dual BSD/GPL");
 #define MAX_LUNS       8
 
        /* Arggh!  There should be a module_param_array_named macro! */
-static char            *file[MAX_LUNS] = {NULL, };
-static int             ro[MAX_LUNS] = {0, };
+static char            *file[MAX_LUNS];
+static int             ro[MAX_LUNS];
 
 static struct {
        int             num_filenames;
@@ -587,7 +587,7 @@ enum fsg_buffer_state {
 struct fsg_buffhd {
        void                            *buf;
        dma_addr_t                      dma;
-       volatile enum fsg_buffer_state  state;
+       enum fsg_buffer_state           state;
        struct fsg_buffhd               *next;
 
        /* The NetChip 2280 is faster, and handles some protocol faults
@@ -596,9 +596,9 @@ struct fsg_buffhd {
        unsigned int                    bulk_out_intended_length;
 
        struct usb_request              *inreq;
-       volatile int                    inreq_busy;
+       int                             inreq_busy;
        struct usb_request              *outreq;
-       volatile int                    outreq_busy;
+       int                             outreq_busy;
 };
 
 enum fsg_state {
@@ -631,13 +631,16 @@ struct fsg_dev {
        /* filesem protects: backing files in use */
        struct rw_semaphore     filesem;
 
+       /* reference counting: wait until all LUNs are released */
+       struct kref             ref;
+
        struct usb_ep           *ep0;           // Handy copy of gadget->ep0
        struct usb_request      *ep0req;        // For control responses
-       volatile unsigned int   ep0_req_tag;
+       unsigned int            ep0_req_tag;
        const char              *ep0req_name;
 
        struct usb_request      *intreq;        // For interrupt responses
-       volatile int            intreq_busy;
+       int                     intreq_busy;
        struct fsg_buffhd       *intr_buffhd;
 
        unsigned int            bulk_out_maxpacket;
@@ -667,7 +670,6 @@ struct fsg_dev {
        struct fsg_buffhd       *next_buffhd_to_drain;
        struct fsg_buffhd       buffhds[NUM_BUFFERS];
 
-       wait_queue_head_t       thread_wqh;
        int                     thread_wakeup_needed;
        struct completion       thread_notifier;
        struct task_struct      *thread_task;
@@ -694,7 +696,6 @@ struct fsg_dev {
        unsigned int            nluns;
        struct lun              *luns;
        struct lun              *curlun;
-       struct completion       lun_released;
 };
 
 typedef void (*fsg_routine_t)(struct fsg_dev *);
@@ -1073,11 +1074,13 @@ static int populate_config_buf(struct usb_gadget *gadget,
 
 /* These routines may be called in process context or in_irq */
 
+/* Caller must hold fsg->lock */
 static void wakeup_thread(struct fsg_dev *fsg)
 {
        /* Tell the main thread that something has happened */
        fsg->thread_wakeup_needed = 1;
-       wake_up_all(&fsg->thread_wqh);
+       if (fsg->thread_task)
+               wake_up_process(fsg->thread_task);
 }
 
 
@@ -1164,11 +1167,12 @@ static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
                usb_ep_fifo_flush(ep);
 
        /* Hold the lock while we update the request and buffer states */
+       smp_wmb();
        spin_lock(&fsg->lock);
        bh->inreq_busy = 0;
        bh->state = BUF_STATE_EMPTY;
-       spin_unlock(&fsg->lock);
        wakeup_thread(fsg);
+       spin_unlock(&fsg->lock);
 }
 
 static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
@@ -1185,11 +1189,12 @@ static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
                usb_ep_fifo_flush(ep);
 
        /* Hold the lock while we update the request and buffer states */
+       smp_wmb();
        spin_lock(&fsg->lock);
        bh->outreq_busy = 0;
        bh->state = BUF_STATE_FULL;
-       spin_unlock(&fsg->lock);
        wakeup_thread(fsg);
+       spin_unlock(&fsg->lock);
 }
 
 
@@ -1206,11 +1211,12 @@ static void intr_in_complete(struct usb_ep *ep, struct usb_request *req)
                usb_ep_fifo_flush(ep);
 
        /* Hold the lock while we update the request and buffer states */
+       smp_wmb();
        spin_lock(&fsg->lock);
        fsg->intreq_busy = 0;
        bh->state = BUF_STATE_EMPTY;
-       spin_unlock(&fsg->lock);
        wakeup_thread(fsg);
+       spin_unlock(&fsg->lock);
 }
 
 #else
@@ -1261,8 +1267,8 @@ static void received_cbi_adsc(struct fsg_dev *fsg, struct fsg_buffhd *bh)
        fsg->cbbuf_cmnd_size = req->actual;
        memcpy(fsg->cbbuf_cmnd, req->buf, fsg->cbbuf_cmnd_size);
 
-       spin_unlock(&fsg->lock);
        wakeup_thread(fsg);
+       spin_unlock(&fsg->lock);
 }
 
 #else
@@ -1514,8 +1520,8 @@ static int fsg_setup(struct usb_gadget *gadget,
 
 /* Use this for bulk or interrupt transfers, not ep0 */
 static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
-               struct usb_request *req, volatile int *pbusy,
-               volatile enum fsg_buffer_state *state)
+               struct usb_request *req, int *pbusy,
+               enum fsg_buffer_state *state)
 {
        int     rc;
 
@@ -1523,8 +1529,11 @@ static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
                dump_msg(fsg, "bulk-in", req->buf, req->length);
        else if (ep == fsg->intr_in)
                dump_msg(fsg, "intr-in", req->buf, req->length);
+
+       spin_lock_irq(&fsg->lock);
        *pbusy = 1;
        *state = BUF_STATE_BUSY;
+       spin_unlock_irq(&fsg->lock);
        rc = usb_ep_queue(ep, req, GFP_KERNEL);
        if (rc != 0) {
                *pbusy = 0;
@@ -1544,14 +1553,23 @@ static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
 
 static int sleep_thread(struct fsg_dev *fsg)
 {
-       int     rc;
+       int     rc = 0;
 
        /* Wait until a signal arrives or we are woken up */
-       rc = wait_event_interruptible(fsg->thread_wqh,
-                       fsg->thread_wakeup_needed);
+       for (;;) {
+               try_to_freeze();
+               set_current_state(TASK_INTERRUPTIBLE);
+               if (signal_pending(current)) {
+                       rc = -EINTR;
+                       break;
+               }
+               if (fsg->thread_wakeup_needed)
+                       break;
+               schedule();
+       }
+       __set_current_state(TASK_RUNNING);
        fsg->thread_wakeup_needed = 0;
-       try_to_freeze();
-       return (rc ? -EINTR : 0);
+       return rc;
 }
 
 
@@ -1788,6 +1806,7 @@ static int do_write(struct fsg_dev *fsg)
                if (bh->state == BUF_STATE_EMPTY && !get_some_more)
                        break;                  // We stopped early
                if (bh->state == BUF_STATE_FULL) {
+                       smp_rmb();
                        fsg->next_buffhd_to_drain = bh->next;
                        bh->state = BUF_STATE_EMPTY;
 
@@ -1872,7 +1891,7 @@ static int fsync_sub(struct lun *curlun)
                return -EINVAL;
 
        inode = filp->f_dentry->d_inode;
-       down(&inode->i_sem);
+       mutex_lock(&inode->i_mutex);
        current->flags |= PF_SYNCWRITE;
        rc = filemap_fdatawrite(inode->i_mapping);
        err = filp->f_op->fsync(filp, filp->f_dentry, 1);
@@ -1882,7 +1901,7 @@ static int fsync_sub(struct lun *curlun)
        if (!rc)
                rc = err;
        current->flags &= ~PF_SYNCWRITE;
-       up(&inode->i_sem);
+       mutex_unlock(&inode->i_mutex);
        VLDBG(curlun, "fdatasync -> %d\n", rc);
        return rc;
 }
@@ -2356,6 +2375,7 @@ static int throw_away_data(struct fsg_dev *fsg)
 
                /* Throw away the data in a filled buffer */
                if (bh->state == BUF_STATE_FULL) {
+                       smp_rmb();
                        bh->state = BUF_STATE_EMPTY;
                        fsg->next_buffhd_to_drain = bh->next;
 
@@ -3021,6 +3041,7 @@ static int get_next_command(struct fsg_dev *fsg)
                        if ((rc = sleep_thread(fsg)) != 0)
                                return rc;
                        }
+               smp_rmb();
                rc = received_cbw(fsg, bh);
                bh->state = BUF_STATE_EMPTY;
 
@@ -3642,11 +3663,19 @@ static DEVICE_ATTR(file, 0444, show_file, NULL);
 
 /*-------------------------------------------------------------------------*/
 
+static void fsg_release(struct kref *ref)
+{
+       struct fsg_dev  *fsg = container_of(ref, struct fsg_dev, ref);
+
+       kfree(fsg->luns);
+       kfree(fsg);
+}
+
 static void lun_release(struct device *dev)
 {
        struct fsg_dev  *fsg = (struct fsg_dev *) dev_get_drvdata(dev);
 
-       complete(&fsg->lun_released);
+       kref_put(&fsg->ref, fsg_release);
 }
 
 static void fsg_unbind(struct usb_gadget *gadget)
@@ -3660,14 +3689,12 @@ static void fsg_unbind(struct usb_gadget *gadget)
        clear_bit(REGISTERED, &fsg->atomic_bitflags);
 
        /* Unregister the sysfs attribute files and the LUNs */
-       init_completion(&fsg->lun_released);
        for (i = 0; i < fsg->nluns; ++i) {
                curlun = &fsg->luns[i];
                if (curlun->registered) {
                        device_remove_file(&curlun->dev, &dev_attr_ro);
                        device_remove_file(&curlun->dev, &dev_attr_file);
                        device_unregister(&curlun->dev);
-                       wait_for_completion(&fsg->lun_released);
                        curlun->registered = 0;
                }
        }
@@ -3846,6 +3873,7 @@ static int __init fsg_bind(struct usb_gadget *gadget)
                        curlun->dev.release = lun_release;
                        device_create_file(&curlun->dev, &dev_attr_ro);
                        device_create_file(&curlun->dev, &dev_attr_file);
+                       kref_get(&fsg->ref);
                }
 
                if (file[i] && *file[i]) {
@@ -4061,7 +4089,7 @@ static int __init fsg_alloc(void)
                return -ENOMEM;
        spin_lock_init(&fsg->lock);
        init_rwsem(&fsg->filesem);
-       init_waitqueue_head(&fsg->thread_wqh);
+       kref_init(&fsg->ref);
        init_completion(&fsg->thread_notifier);
 
        the_fsg = fsg;
@@ -4069,13 +4097,6 @@ static int __init fsg_alloc(void)
 }
 
 
-static void fsg_free(struct fsg_dev *fsg)
-{
-       kfree(fsg->luns);
-       kfree(fsg);
-}
-
-
 static int __init fsg_init(void)
 {
        int             rc;
@@ -4085,7 +4106,7 @@ static int __init fsg_init(void)
                return rc;
        fsg = the_fsg;
        if ((rc = usb_gadget_register_driver(&fsg_driver)) != 0)
-               fsg_free(fsg);
+               kref_put(&fsg->ref, fsg_release);
        return rc;
 }
 module_init(fsg_init);
@@ -4103,6 +4124,6 @@ static void __exit fsg_cleanup(void)
        wait_for_completion(&fsg->thread_notifier);
 
        close_all_backing_files(fsg);
-       fsg_free(fsg);
+       kref_put(&fsg->ref, fsg_release);
 }
 module_exit(fsg_cleanup);