mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-22 01:47:47 +07:00
usb: usbtmc: Support Read Status Byte with SRQ per file
Add 'struct usbtmc_file_data' for each file handle to cache last srq_byte (=Status Byte with SRQ) received by usbtmc_interrupt(..) usbtmc488_ioctl_read_stb returns cached srq_byte when available for each file handle to avoid race conditions of concurrent applications. SRQ now sets EPOLLPRI instead of EPOLLIN since EPOLLIN is now reserved for asynchronous reads Tested-by: Dave Penkler <dpenkler@gmail.com> Reviewed-by: Steve Bayless <steve_bayless@keysight.com> Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Guido Kiener
Greg Kroah-Hartman
parent
04b453c859
commit
4f3c8d6edd
@ -67,6 +67,7 @@ struct usbtmc_device_data {
|
||||
const struct usb_device_id *id;
|
||||
struct usb_device *usb_dev;
|
||||
struct usb_interface *intf;
|
||||
struct list_head file_list;
|
||||
|
||||
unsigned int bulk_in;
|
||||
unsigned int bulk_out;
|
||||
@ -87,7 +88,6 @@ struct usbtmc_device_data {
|
||||
int iin_interval;
|
||||
struct urb *iin_urb;
|
||||
u16 iin_wMaxPacketSize;
|
||||
atomic_t srq_asserted;
|
||||
|
||||
/* coalesced usb488_caps from usbtmc_dev_capabilities */
|
||||
__u8 usb488_caps;
|
||||
@ -104,9 +104,21 @@ struct usbtmc_device_data {
|
||||
struct mutex io_mutex; /* only one i/o function running at a time */
|
||||
wait_queue_head_t waitq;
|
||||
struct fasync_struct *fasync;
|
||||
spinlock_t dev_lock; /* lock for file_list */
|
||||
};
|
||||
#define to_usbtmc_data(d) container_of(d, struct usbtmc_device_data, kref)
|
||||
|
||||
/*
|
||||
* This structure holds private data for each USBTMC file handle.
|
||||
*/
|
||||
struct usbtmc_file_data {
|
||||
struct usbtmc_device_data *data;
|
||||
struct list_head file_elem;
|
||||
|
||||
u8 srq_byte;
|
||||
atomic_t srq_asserted;
|
||||
};
|
||||
|
||||
/* Forward declarations */
|
||||
static struct usb_driver usbtmc_driver;
|
||||
|
||||
@ -122,7 +134,7 @@ static int usbtmc_open(struct inode *inode, struct file *filp)
|
||||
{
|
||||
struct usb_interface *intf;
|
||||
struct usbtmc_device_data *data;
|
||||
int retval = 0;
|
||||
struct usbtmc_file_data *file_data;
|
||||
|
||||
intf = usb_find_interface(&usbtmc_driver, iminor(inode));
|
||||
if (!intf) {
|
||||
@ -130,21 +142,45 @@ static int usbtmc_open(struct inode *inode, struct file *filp)
|
||||
return -ENODEV;
|
||||
}
|
||||
|
||||
file_data = kzalloc(sizeof(*file_data), GFP_KERNEL);
|
||||
if (!file_data)
|
||||
return -ENOMEM;
|
||||
|
||||
data = usb_get_intfdata(intf);
|
||||
/* Protect reference to data from file structure until release */
|
||||
kref_get(&data->kref);
|
||||
|
||||
/* Store pointer in file structure's private data field */
|
||||
filp->private_data = data;
|
||||
mutex_lock(&data->io_mutex);
|
||||
file_data->data = data;
|
||||
|
||||
return retval;
|
||||
INIT_LIST_HEAD(&file_data->file_elem);
|
||||
spin_lock_irq(&data->dev_lock);
|
||||
list_add_tail(&file_data->file_elem, &data->file_list);
|
||||
spin_unlock_irq(&data->dev_lock);
|
||||
mutex_unlock(&data->io_mutex);
|
||||
|
||||
/* Store pointer in file structure's private data field */
|
||||
filp->private_data = file_data;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int usbtmc_release(struct inode *inode, struct file *file)
|
||||
{
|
||||
struct usbtmc_device_data *data = file->private_data;
|
||||
struct usbtmc_file_data *file_data = file->private_data;
|
||||
|
||||
kref_put(&data->kref, usbtmc_delete);
|
||||
/* prevent IO _AND_ usbtmc_interrupt */
|
||||
mutex_lock(&file_data->data->io_mutex);
|
||||
spin_lock_irq(&file_data->data->dev_lock);
|
||||
|
||||
list_del(&file_data->file_elem);
|
||||
|
||||
spin_unlock_irq(&file_data->data->dev_lock);
|
||||
mutex_unlock(&file_data->data->io_mutex);
|
||||
|
||||
kref_put(&file_data->data->kref, usbtmc_delete);
|
||||
file_data->data = NULL;
|
||||
kfree(file_data);
|
||||
return 0;
|
||||
}
|
||||
|
||||
@ -369,10 +405,12 @@ static int usbtmc_ioctl_abort_bulk_out(struct usbtmc_device_data *data)
|
||||
return rv;
|
||||
}
|
||||
|
||||
static int usbtmc488_ioctl_read_stb(struct usbtmc_device_data *data,
|
||||
static int usbtmc488_ioctl_read_stb(struct usbtmc_file_data *file_data,
|
||||
void __user *arg)
|
||||
{
|
||||
struct usbtmc_device_data *data = file_data->data;
|
||||
struct device *dev = &data->intf->dev;
|
||||
int srq_asserted = 0;
|
||||
u8 *buffer;
|
||||
u8 tag;
|
||||
__u8 stb;
|
||||
@ -381,15 +419,25 @@ static int usbtmc488_ioctl_read_stb(struct usbtmc_device_data *data,
|
||||
dev_dbg(dev, "Enter ioctl_read_stb iin_ep_present: %d\n",
|
||||
data->iin_ep_present);
|
||||
|
||||
spin_lock_irq(&data->dev_lock);
|
||||
srq_asserted = atomic_xchg(&file_data->srq_asserted, srq_asserted);
|
||||
if (srq_asserted) {
|
||||
/* a STB with SRQ is already received */
|
||||
stb = file_data->srq_byte;
|
||||
spin_unlock_irq(&data->dev_lock);
|
||||
rv = put_user(stb, (__u8 __user *)arg);
|
||||
dev_dbg(dev, "stb:0x%02x with srq received %d\n",
|
||||
(unsigned int)stb, rv);
|
||||
return rv;
|
||||
}
|
||||
spin_unlock_irq(&data->dev_lock);
|
||||
|
||||
buffer = kmalloc(8, GFP_KERNEL);
|
||||
if (!buffer)
|
||||
return -ENOMEM;
|
||||
|
||||
atomic_set(&data->iin_data_valid, 0);
|
||||
|
||||
/* must issue read_stb before using poll or select */
|
||||
atomic_set(&data->srq_asserted, 0);
|
||||
|
||||
rv = usb_control_msg(data->usb_dev,
|
||||
usb_rcvctrlpipe(data->usb_dev, 0),
|
||||
USBTMC488_REQUEST_READ_STATUS_BYTE,
|
||||
@ -435,9 +483,8 @@ static int usbtmc488_ioctl_read_stb(struct usbtmc_device_data *data,
|
||||
stb = buffer[2];
|
||||
}
|
||||
|
||||
rv = copy_to_user(arg, &stb, sizeof(stb));
|
||||
if (rv)
|
||||
rv = -EFAULT;
|
||||
rv = put_user(stb, (__u8 __user *)arg);
|
||||
dev_dbg(dev, "stb:0x%02x received %d\n", (unsigned int)stb, rv);
|
||||
|
||||
exit:
|
||||
/* bump interrupt bTag */
|
||||
@ -565,6 +612,7 @@ static int send_request_dev_dep_msg_in(struct usbtmc_device_data *data, size_t t
|
||||
static ssize_t usbtmc_read(struct file *filp, char __user *buf,
|
||||
size_t count, loff_t *f_pos)
|
||||
{
|
||||
struct usbtmc_file_data *file_data;
|
||||
struct usbtmc_device_data *data;
|
||||
struct device *dev;
|
||||
u32 n_characters;
|
||||
@ -576,7 +624,8 @@ static ssize_t usbtmc_read(struct file *filp, char __user *buf,
|
||||
size_t this_part;
|
||||
|
||||
/* Get pointer to private data structure */
|
||||
data = filp->private_data;
|
||||
file_data = filp->private_data;
|
||||
data = file_data->data;
|
||||
dev = &data->intf->dev;
|
||||
|
||||
buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
|
||||
@ -721,6 +770,7 @@ static ssize_t usbtmc_read(struct file *filp, char __user *buf,
|
||||
static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
|
||||
size_t count, loff_t *f_pos)
|
||||
{
|
||||
struct usbtmc_file_data *file_data;
|
||||
struct usbtmc_device_data *data;
|
||||
u8 *buffer;
|
||||
int retval;
|
||||
@ -730,7 +780,8 @@ static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
|
||||
int done;
|
||||
int this_part;
|
||||
|
||||
data = filp->private_data;
|
||||
file_data = filp->private_data;
|
||||
data = file_data->data;
|
||||
|
||||
buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
|
||||
if (!buffer)
|
||||
@ -1140,10 +1191,13 @@ static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
|
||||
|
||||
static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
||||
{
|
||||
struct usbtmc_file_data *file_data;
|
||||
struct usbtmc_device_data *data;
|
||||
int retval = -EBADRQC;
|
||||
|
||||
data = file->private_data;
|
||||
file_data = file->private_data;
|
||||
data = file_data->data;
|
||||
|
||||
mutex_lock(&data->io_mutex);
|
||||
if (data->zombie) {
|
||||
retval = -ENODEV;
|
||||
@ -1184,7 +1238,8 @@ static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
||||
break;
|
||||
|
||||
case USBTMC488_IOCTL_READ_STB:
|
||||
retval = usbtmc488_ioctl_read_stb(data, (void __user *)arg);
|
||||
retval = usbtmc488_ioctl_read_stb(file_data,
|
||||
(void __user *)arg);
|
||||
break;
|
||||
|
||||
case USBTMC488_IOCTL_REN_CONTROL:
|
||||
@ -1210,14 +1265,15 @@ static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
||||
|
||||
static int usbtmc_fasync(int fd, struct file *file, int on)
|
||||
{
|
||||
struct usbtmc_device_data *data = file->private_data;
|
||||
struct usbtmc_file_data *file_data = file->private_data;
|
||||
|
||||
return fasync_helper(fd, file, on, &data->fasync);
|
||||
return fasync_helper(fd, file, on, &file_data->data->fasync);
|
||||
}
|
||||
|
||||
static __poll_t usbtmc_poll(struct file *file, poll_table *wait)
|
||||
{
|
||||
struct usbtmc_device_data *data = file->private_data;
|
||||
struct usbtmc_file_data *file_data = file->private_data;
|
||||
struct usbtmc_device_data *data = file_data->data;
|
||||
__poll_t mask;
|
||||
|
||||
mutex_lock(&data->io_mutex);
|
||||
@ -1229,7 +1285,7 @@ static __poll_t usbtmc_poll(struct file *file, poll_table *wait)
|
||||
|
||||
poll_wait(file, &data->waitq, wait);
|
||||
|
||||
mask = (atomic_read(&data->srq_asserted)) ? EPOLLIN | EPOLLRDNORM : 0;
|
||||
mask = (atomic_read(&file_data->srq_asserted)) ? EPOLLPRI : 0;
|
||||
|
||||
no_poll:
|
||||
mutex_unlock(&data->io_mutex);
|
||||
@ -1276,15 +1332,33 @@ static void usbtmc_interrupt(struct urb *urb)
|
||||
}
|
||||
/* check for SRQ notification */
|
||||
if (data->iin_buffer[0] == 0x81) {
|
||||
unsigned long flags;
|
||||
struct list_head *elem;
|
||||
|
||||
if (data->fasync)
|
||||
kill_fasync(&data->fasync,
|
||||
SIGIO, POLL_IN);
|
||||
SIGIO, POLL_PRI);
|
||||
|
||||
atomic_set(&data->srq_asserted, 1);
|
||||
wake_up_interruptible(&data->waitq);
|
||||
spin_lock_irqsave(&data->dev_lock, flags);
|
||||
list_for_each(elem, &data->file_list) {
|
||||
struct usbtmc_file_data *file_data;
|
||||
|
||||
file_data = list_entry(elem,
|
||||
struct usbtmc_file_data,
|
||||
file_elem);
|
||||
file_data->srq_byte = data->iin_buffer[1];
|
||||
atomic_set(&file_data->srq_asserted, 1);
|
||||
}
|
||||
spin_unlock_irqrestore(&data->dev_lock, flags);
|
||||
|
||||
dev_dbg(dev, "srq received bTag %x stb %x\n",
|
||||
(unsigned int)data->iin_buffer[0],
|
||||
(unsigned int)data->iin_buffer[1]);
|
||||
wake_up_interruptible_all(&data->waitq);
|
||||
goto exit;
|
||||
}
|
||||
dev_warn(dev, "invalid notification: %x\n", data->iin_buffer[0]);
|
||||
dev_warn(dev, "invalid notification: %x\n",
|
||||
data->iin_buffer[0]);
|
||||
break;
|
||||
case -EOVERFLOW:
|
||||
dev_err(dev, "overflow with length %d, actual length is %d\n",
|
||||
@ -1295,6 +1369,7 @@ static void usbtmc_interrupt(struct urb *urb)
|
||||
case -ESHUTDOWN:
|
||||
case -EILSEQ:
|
||||
case -ETIME:
|
||||
case -EPIPE:
|
||||
/* urb terminated, clean up */
|
||||
dev_dbg(dev, "urb terminated, status: %d\n", status);
|
||||
return;
|
||||
@ -1339,7 +1414,9 @@ static int usbtmc_probe(struct usb_interface *intf,
|
||||
mutex_init(&data->io_mutex);
|
||||
init_waitqueue_head(&data->waitq);
|
||||
atomic_set(&data->iin_data_valid, 0);
|
||||
atomic_set(&data->srq_asserted, 0);
|
||||
INIT_LIST_HEAD(&data->file_list);
|
||||
spin_lock_init(&data->dev_lock);
|
||||
|
||||
data->zombie = 0;
|
||||
|
||||
/* Initialize USBTMC bTag and other fields */
|
||||
@ -1442,17 +1519,14 @@ static int usbtmc_probe(struct usb_interface *intf,
|
||||
|
||||
static void usbtmc_disconnect(struct usb_interface *intf)
|
||||
{
|
||||
struct usbtmc_device_data *data;
|
||||
struct usbtmc_device_data *data = usb_get_intfdata(intf);
|
||||
|
||||
dev_dbg(&intf->dev, "usbtmc_disconnect called\n");
|
||||
|
||||
data = usb_get_intfdata(intf);
|
||||
usb_deregister_dev(intf, &usbtmc_class);
|
||||
sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
|
||||
sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
|
||||
mutex_lock(&data->io_mutex);
|
||||
data->zombie = 1;
|
||||
wake_up_all(&data->waitq);
|
||||
wake_up_interruptible_all(&data->waitq);
|
||||
mutex_unlock(&data->io_mutex);
|
||||
usbtmc_free_int(data);
|
||||
kref_put(&data->kref, usbtmc_delete);
|
||||
|
||||
Loading…
Reference in New Issue
Block a user