From d635711daa98be86d4c7fd01499c34f566b54ccb Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Fri, 10 Jun 2016 05:30:17 -0300 Subject: Linux-libre 4.6.2-gnu --- drivers/usb/misc/chaoskey.c | 122 ++++++++++++++++++++++++++++++-------------- 1 file changed, 83 insertions(+), 39 deletions(-) (limited to 'drivers/usb/misc/chaoskey.c') diff --git a/drivers/usb/misc/chaoskey.c b/drivers/usb/misc/chaoskey.c index 23c794813..76350e4ee 100644 --- a/drivers/usb/misc/chaoskey.c +++ b/drivers/usb/misc/chaoskey.c @@ -73,6 +73,8 @@ static const struct usb_device_id chaoskey_table[] = { }; MODULE_DEVICE_TABLE(usb, chaoskey_table); +static void chaos_read_callback(struct urb *urb); + /* Driver-local specific stuff */ struct chaoskey { struct usb_interface *interface; @@ -80,7 +82,8 @@ struct chaoskey { struct mutex lock; struct mutex rng_lock; int open; /* open count */ - int present; /* device not disconnected */ + bool present; /* device not disconnected */ + bool reading; /* ongoing IO */ int size; /* size of buf */ int valid; /* bytes of buf read */ int used; /* bytes of buf consumed */ @@ -88,15 +91,19 @@ struct chaoskey { struct hwrng hwrng; /* Embedded struct for hwrng */ int hwrng_registered; /* registered with hwrng API */ wait_queue_head_t wait_q; /* for timeouts */ + struct urb *urb; /* for performing IO */ char *buf; }; static void chaoskey_free(struct chaoskey *dev) { - usb_dbg(dev->interface, "free"); - kfree(dev->name); - kfree(dev->buf); - kfree(dev); + if (dev) { + usb_dbg(dev->interface, "free"); + usb_free_urb(dev->urb); + kfree(dev->name); + kfree(dev->buf); + kfree(dev); + } } static int chaoskey_probe(struct usb_interface *interface, @@ -107,7 +114,7 @@ static int chaoskey_probe(struct usb_interface *interface, int i; int in_ep = -1; struct chaoskey *dev; - int result; + int result = -ENOMEM; int size; usb_dbg(interface, "probe %s-%s", udev->product, udev->serial); @@ -142,14 +149,25 @@ static int chaoskey_probe(struct usb_interface *interface, dev = kzalloc(sizeof(struct chaoskey), GFP_KERNEL); if (dev == NULL) - return -ENOMEM; + goto out; dev->buf = kmalloc(size, GFP_KERNEL); - if (dev->buf == NULL) { - kfree(dev); - return -ENOMEM; - } + if (dev->buf == NULL) + goto out; + + dev->urb = usb_alloc_urb(0, GFP_KERNEL); + + if (!dev->urb) + goto out; + + usb_fill_bulk_urb(dev->urb, + udev, + usb_rcvbulkpipe(udev, in_ep), + dev->buf, + size, + chaos_read_callback, + dev); /* Construct a name using the product and serial values. Each * device needs a unique name for the hwrng code @@ -158,11 +176,8 @@ static int chaoskey_probe(struct usb_interface *interface, if (udev->product && udev->serial) { dev->name = kmalloc(strlen(udev->product) + 1 + strlen(udev->serial) + 1, GFP_KERNEL); - if (dev->name == NULL) { - kfree(dev->buf); - kfree(dev); - return -ENOMEM; - } + if (dev->name == NULL) + goto out; strcpy(dev->name, udev->product); strcat(dev->name, "-"); @@ -186,9 +201,7 @@ static int chaoskey_probe(struct usb_interface *interface, result = usb_register_dev(interface, &chaoskey_class); if (result) { usb_err(interface, "Unable to allocate minor number."); - usb_set_intfdata(interface, NULL); - chaoskey_free(dev); - return result; + goto out; } dev->hwrng.name = dev->name ? dev->name : chaoskey_driver.name; @@ -215,6 +228,11 @@ static int chaoskey_probe(struct usb_interface *interface, usb_dbg(interface, "chaoskey probe success, size %d", dev->size); return 0; + +out: + usb_set_intfdata(interface, NULL); + chaoskey_free(dev); + return result; } static void chaoskey_disconnect(struct usb_interface *interface) @@ -237,6 +255,7 @@ static void chaoskey_disconnect(struct usb_interface *interface) mutex_lock(&dev->lock); dev->present = 0; + usb_poison_urb(dev->urb); if (!dev->open) { mutex_unlock(&dev->lock); @@ -311,14 +330,33 @@ static int chaoskey_release(struct inode *inode, struct file *file) return 0; } +static void chaos_read_callback(struct urb *urb) +{ + struct chaoskey *dev = urb->context; + int status = urb->status; + + usb_dbg(dev->interface, "callback status (%d)", status); + + if (status == 0) + dev->valid = urb->actual_length; + else + dev->valid = 0; + + dev->used = 0; + + /* must be seen first before validity is announced */ + smp_wmb(); + + dev->reading = false; + wake_up(&dev->wait_q); +} + /* Fill the buffer. Called with dev->lock held */ static int _chaoskey_fill(struct chaoskey *dev) { DEFINE_WAIT(wait); int result; - int this_read; - struct usb_device *udev = interface_to_usbdev(dev->interface); usb_dbg(dev->interface, "fill"); @@ -343,21 +381,31 @@ static int _chaoskey_fill(struct chaoskey *dev) return result; } - result = usb_bulk_msg(udev, - usb_rcvbulkpipe(udev, dev->in_ep), - dev->buf, dev->size, &this_read, - NAK_TIMEOUT); + dev->reading = true; + result = usb_submit_urb(dev->urb, GFP_KERNEL); + if (result < 0) { + result = usb_translate_errors(result); + dev->reading = false; + goto out; + } + + result = wait_event_interruptible_timeout( + dev->wait_q, + !dev->reading, + NAK_TIMEOUT); + + if (result < 0) + goto out; + if (result == 0) + result = -ETIMEDOUT; + else + result = dev->valid; +out: /* Let the device go back to sleep eventually */ usb_autopm_put_interface(dev->interface); - if (result == 0) { - dev->valid = this_read; - dev->used = 0; - } - - usb_dbg(dev->interface, "bulk_msg result %d this_read %d", - result, this_read); + usb_dbg(dev->interface, "read %d bytes", dev->valid); return result; } @@ -395,13 +443,7 @@ static ssize_t chaoskey_read(struct file *file, goto bail; if (dev->valid == dev->used) { result = _chaoskey_fill(dev); - if (result) { - mutex_unlock(&dev->lock); - goto bail; - } - - /* Read returned zero bytes */ - if (dev->used == dev->valid) { + if (result < 0) { mutex_unlock(&dev->lock); goto bail; } @@ -435,6 +477,8 @@ bail: return read_count; } usb_dbg(dev->interface, "empty read, result %d", result); + if (result == -ETIMEDOUT) + result = -EAGAIN; return result; } -- cgit v1.2.3-54-g00ecf