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ieee1394: raw1394: narrow down the state_mutex protected region
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Refactor the ioctl dispatcher in order to move a fraction of it out of
the section which is serialized by fi->state_mutex.  This is not so much
about performance but more about self-documentation:  The mutex_lock()/
mutex_unlock() calls are now closer to the data accesses which the mutex
protects, i.e. to the iso_state switch.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
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Stefan Richter committed Oct 15, 2008
1 parent 10963ea commit ddfb908
Showing 1 changed file with 110 additions and 101 deletions.
211 changes: 110 additions & 101 deletions drivers/ieee1394/raw1394.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2556,102 +2556,106 @@ static int raw1394_mmap(struct file *file, struct vm_area_struct *vma)
return ret;
}

/* ioctl is only used for rawiso operations */
static long do_raw1394_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
static long raw1394_ioctl_inactive(struct file_info *fi, unsigned int cmd,
void __user *argp)
{
switch (cmd) {
case RAW1394_IOC_ISO_XMIT_INIT:
return raw1394_iso_xmit_init(fi, argp);
case RAW1394_IOC_ISO_RECV_INIT:
return raw1394_iso_recv_init(fi, argp);
default:
return -EINVAL;
}
}

static long raw1394_ioctl_recv(struct file_info *fi, unsigned int cmd,
unsigned long arg)
{
struct file_info *fi = file->private_data;
void __user *argp = (void __user *)arg;

switch (fi->iso_state) {
case RAW1394_ISO_INACTIVE:
switch (cmd) {
case RAW1394_IOC_ISO_XMIT_INIT:
return raw1394_iso_xmit_init(fi, argp);
case RAW1394_IOC_ISO_RECV_INIT:
return raw1394_iso_recv_init(fi, argp);
default:
break;
switch (cmd) {
case RAW1394_IOC_ISO_RECV_START:{
int args[3];

if (copy_from_user(&args[0], argp, sizeof(args)))
return -EFAULT;
return hpsb_iso_recv_start(fi->iso_handle,
args[0], args[1], args[2]);
}
break;
case RAW1394_ISO_RECV:
switch (cmd) {
case RAW1394_IOC_ISO_RECV_START:{
/* copy args from user-space */
int args[3];
if (copy_from_user
(&args[0], argp, sizeof(args)))
return -EFAULT;
return hpsb_iso_recv_start(fi->iso_handle,
args[0], args[1],
args[2]);
}
case RAW1394_IOC_ISO_XMIT_RECV_STOP:
hpsb_iso_stop(fi->iso_handle);
return 0;
case RAW1394_IOC_ISO_RECV_LISTEN_CHANNEL:
return hpsb_iso_recv_listen_channel(fi->iso_handle,
arg);
case RAW1394_IOC_ISO_RECV_UNLISTEN_CHANNEL:
return hpsb_iso_recv_unlisten_channel(fi->iso_handle,
arg);
case RAW1394_IOC_ISO_RECV_SET_CHANNEL_MASK:{
/* copy the u64 from user-space */
u64 mask;
if (copy_from_user(&mask, argp, sizeof(mask)))
return -EFAULT;
return hpsb_iso_recv_set_channel_mask(fi->
iso_handle,
mask);
}
case RAW1394_IOC_ISO_GET_STATUS:
return raw1394_iso_get_status(fi, argp);
case RAW1394_IOC_ISO_RECV_PACKETS:
return raw1394_iso_recv_packets(fi, argp);
case RAW1394_IOC_ISO_RECV_RELEASE_PACKETS:
return hpsb_iso_recv_release_packets(fi->iso_handle,
arg);
case RAW1394_IOC_ISO_RECV_FLUSH:
return hpsb_iso_recv_flush(fi->iso_handle);
case RAW1394_IOC_ISO_SHUTDOWN:
raw1394_iso_shutdown(fi);
return 0;
case RAW1394_IOC_ISO_QUEUE_ACTIVITY:
queue_rawiso_event(fi);
return 0;
case RAW1394_IOC_ISO_XMIT_RECV_STOP:
hpsb_iso_stop(fi->iso_handle);
return 0;
case RAW1394_IOC_ISO_RECV_LISTEN_CHANNEL:
return hpsb_iso_recv_listen_channel(fi->iso_handle, arg);
case RAW1394_IOC_ISO_RECV_UNLISTEN_CHANNEL:
return hpsb_iso_recv_unlisten_channel(fi->iso_handle, arg);
case RAW1394_IOC_ISO_RECV_SET_CHANNEL_MASK:{
u64 mask;

if (copy_from_user(&mask, argp, sizeof(mask)))
return -EFAULT;
return hpsb_iso_recv_set_channel_mask(fi->iso_handle,
mask);
}
break;
case RAW1394_ISO_XMIT:
switch (cmd) {
case RAW1394_IOC_ISO_XMIT_START:{
/* copy two ints from user-space */
int args[2];
if (copy_from_user
(&args[0], argp, sizeof(args)))
return -EFAULT;
return hpsb_iso_xmit_start(fi->iso_handle,
args[0], args[1]);
}
case RAW1394_IOC_ISO_XMIT_SYNC:
return hpsb_iso_xmit_sync(fi->iso_handle);
case RAW1394_IOC_ISO_XMIT_RECV_STOP:
hpsb_iso_stop(fi->iso_handle);
return 0;
case RAW1394_IOC_ISO_GET_STATUS:
return raw1394_iso_get_status(fi, argp);
case RAW1394_IOC_ISO_XMIT_PACKETS:
return raw1394_iso_send_packets(fi, argp);
case RAW1394_IOC_ISO_SHUTDOWN:
raw1394_iso_shutdown(fi);
return 0;
case RAW1394_IOC_ISO_QUEUE_ACTIVITY:
queue_rawiso_event(fi);
return 0;
case RAW1394_IOC_ISO_GET_STATUS:
return raw1394_iso_get_status(fi, argp);
case RAW1394_IOC_ISO_RECV_PACKETS:
return raw1394_iso_recv_packets(fi, argp);
case RAW1394_IOC_ISO_RECV_RELEASE_PACKETS:
return hpsb_iso_recv_release_packets(fi->iso_handle, arg);
case RAW1394_IOC_ISO_RECV_FLUSH:
return hpsb_iso_recv_flush(fi->iso_handle);
case RAW1394_IOC_ISO_SHUTDOWN:
raw1394_iso_shutdown(fi);
return 0;
case RAW1394_IOC_ISO_QUEUE_ACTIVITY:
queue_rawiso_event(fi);
return 0;
default:
return -EINVAL;
}
}

static long raw1394_ioctl_xmit(struct file_info *fi, unsigned int cmd,
void __user *argp)
{
switch (cmd) {
case RAW1394_IOC_ISO_XMIT_START:{
int args[2];

if (copy_from_user(&args[0], argp, sizeof(args)))
return -EFAULT;
return hpsb_iso_xmit_start(fi->iso_handle,
args[0], args[1]);
}
break;
case RAW1394_IOC_ISO_XMIT_SYNC:
return hpsb_iso_xmit_sync(fi->iso_handle);
case RAW1394_IOC_ISO_XMIT_RECV_STOP:
hpsb_iso_stop(fi->iso_handle);
return 0;
case RAW1394_IOC_ISO_GET_STATUS:
return raw1394_iso_get_status(fi, argp);
case RAW1394_IOC_ISO_XMIT_PACKETS:
return raw1394_iso_send_packets(fi, argp);
case RAW1394_IOC_ISO_SHUTDOWN:
raw1394_iso_shutdown(fi);
return 0;
case RAW1394_IOC_ISO_QUEUE_ACTIVITY:
queue_rawiso_event(fi);
return 0;
default:
break;
return -EINVAL;
}
}

/* ioctl is only used for rawiso operations */
static long raw1394_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct file_info *fi = file->private_data;
void __user *argp = (void __user *)arg;
long ret;

/* state-independent commands */
switch(cmd) {
Expand All @@ -2661,18 +2665,25 @@ static long do_raw1394_ioctl(struct file *file, unsigned int cmd,
break;
}

return -EINVAL;
}
mutex_lock(&fi->state_mutex);

static long raw1394_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct file_info *fi = file->private_data;
long ret;
switch (fi->iso_state) {
case RAW1394_ISO_INACTIVE:
ret = raw1394_ioctl_inactive(fi, cmd, argp);
break;
case RAW1394_ISO_RECV:
ret = raw1394_ioctl_recv(fi, cmd, arg);
break;
case RAW1394_ISO_XMIT:
ret = raw1394_ioctl_xmit(fi, cmd, argp);
break;
default:
ret = -EINVAL;
break;
}

mutex_lock(&fi->state_mutex);
ret = do_raw1394_ioctl(file, cmd, arg);
mutex_unlock(&fi->state_mutex);

return ret;
}

Expand Down Expand Up @@ -2710,7 +2721,7 @@ static long raw1394_iso_xmit_recv_packets32(struct file *file, unsigned int cmd,
!copy_from_user(&infos32, &arg->infos, sizeof infos32)) {
infos = compat_ptr(infos32);
if (!copy_to_user(&dst->infos, &infos, sizeof infos))
err = do_raw1394_ioctl(file, cmd, (unsigned long)dst);
err = raw1394_ioctl(file, cmd, (unsigned long)dst);
}
return err;
}
Expand All @@ -2734,7 +2745,6 @@ static long raw1394_compat_ioctl(struct file *file,
void __user *argp = (void __user *)arg;
long err;

mutex_lock(&fi->state_mutex);
switch (cmd) {
/* These requests have same format as long as 'int' has same size. */
case RAW1394_IOC_ISO_RECV_INIT:
Expand All @@ -2751,7 +2761,7 @@ static long raw1394_compat_ioctl(struct file *file,
case RAW1394_IOC_ISO_GET_STATUS:
case RAW1394_IOC_ISO_SHUTDOWN:
case RAW1394_IOC_ISO_QUEUE_ACTIVITY:
err = do_raw1394_ioctl(file, cmd, arg);
err = raw1394_ioctl(file, cmd, arg);
break;
/* These request have different format. */
case RAW1394_IOC_ISO_RECV_PACKETS32:
Expand All @@ -2767,7 +2777,6 @@ static long raw1394_compat_ioctl(struct file *file,
err = -EINVAL;
break;
}
mutex_unlock(&fi->state_mutex);

return err;
}
Expand Down

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