V4L/DVB (3501): Dmxdev: use dvb_ringbuffer

Use dvb_ringbuffer instead of an own buffer implementation in
dmxdev.[ch].

Signed-off-by: Andreas Oberritter <obi@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

2 files changed, 62 insertions, 108 deletions

diff --git a/drivers/media/dvb/dvb-core/dmxdev.c b/drivers/media/dvb/dvb-core/dmxdev.c
index f6932d6c62e3..09e96e9ddbdf 100644
--- a/drivers/media/dvb/dvb-core/dmxdev.c
+++ b/drivers/media/dvb/dvb-core/dmxdev.c
@@ -40,110 +40,72 @@ MODULE_PARM_DESC(debug, "Turn on/off debugging (default:off).");
 
 #define dprintk if (debug) printk
 
-static inline void dvb_dmxdev_buffer_init(struct dmxdev_buffer *buffer)
+static int dvb_dmxdev_buffer_write(struct dvb_ringbuffer *buf,
+                                   const u8 *src, size_t len)
 {
-        buffer->data = NULL;
-        buffer->size = 8192;
-        buffer->pread = 0;
-        buffer->pwrite = 0;
-        buffer->error = 0;
-        init_waitqueue_head(&buffer->queue);
-}
-
-static inline int dvb_dmxdev_buffer_write(struct dmxdev_buffer *buf,
-                                          const u8 *src, int len)
-{
-        int split;
-        int free;
-        int todo;
+        ssize_t free;
 
         if (!len)
                 return 0;
         if (!buf->data)
                 return 0;
 
-        free = buf->pread - buf->pwrite;
-        split = 0;
-        if (free <= 0) {
-                free += buf->size;
-                split = buf->size - buf->pwrite;
-        }
-        if (len >= free) {
+        free = dvb_ringbuffer_free(buf);
+        if (len > free) {
                 dprintk("dmxdev: buffer overflow\n");
-                return -1;
-        }
-        if (split >= len)
-                split = 0;
-        todo = len;
-        if (split) {
-                memcpy(buf->data + buf->pwrite, src, split);
-                todo -= split;
-                buf->pwrite = 0;
+                return -EOVERFLOW;
         }
-        memcpy(buf->data + buf->pwrite, src + split, todo);
-        buf->pwrite = (buf->pwrite + todo) % buf->size;
-        return len;
+
+        return dvb_ringbuffer_write(buf, src, len);
 }
 
-static ssize_t dvb_dmxdev_buffer_read(struct dmxdev_buffer *src,
+static ssize_t dvb_dmxdev_buffer_read(struct dvb_ringbuffer *src,
                                       int non_blocking, char __user *buf,
                                       size_t count, loff_t *ppos)
 {
-        unsigned long todo = count;
-        int split, avail, error;
+        size_t todo;
+        ssize_t avail;
+        ssize_t ret = 0;
 
         if (!src->data)
                 return 0;
 
-        if ((error = src->error)) {
-                src->pwrite = src->pread;
-                src->error = 0;
-                return error;
+        if (src->error) {
+                ret = src->error;
+                dvb_ringbuffer_flush(src);
+                return ret;
         }
 
-        if (non_blocking && (src->pwrite == src->pread))
-                return -EWOULDBLOCK;
-
-        while (todo > 0) {
-                if (non_blocking && (src->pwrite == src->pread))
-                        return (count - todo) ? (count - todo) : -EWOULDBLOCK;
+        for (todo = count; todo > 0; todo -= ret) {
+                if (non_blocking && dvb_ringbuffer_empty(src)) {
+                        ret = -EWOULDBLOCK;
+                        break;
+                }
 
-                if (wait_event_interruptible(src->queue,
-                                             (src->pread != src->pwrite) ||
-                                             (src->error)) < 0)
-                        return count - todo;
+                ret = wait_event_interruptible(src->queue,
+                                               !dvb_ringbuffer_empty(src) ||
+                                               (src->error != 0));
+                if (ret < 0)
+                        break;
 
-                if ((error = src->error)) {
-                        src->pwrite = src->pread;
-                        src->error = 0;
-                        return error;
+                if (src->error) {
+                        ret = src->error;
+                        dvb_ringbuffer_flush(src);
+                        break;
                 }
 
-                split = src->size;
-                avail = src->pwrite - src->pread;
-                if (avail < 0) {
-                        avail += src->size;
-                        split = src->size - src->pread;
-                }
+                avail = dvb_ringbuffer_avail(src);
                 if (avail > todo)
                         avail = todo;
-                if (split < avail) {
-                        if (copy_to_user(buf, src->data + src->pread, split))
-                                return -EFAULT;
-                        buf += split;
-                        src->pread = 0;
-                        todo -= split;
-                        avail -= split;
-                }
-                if (avail) {
-                        if (copy_to_user(buf, src->data + src->pread, avail))
-                                return -EFAULT;
-                        src->pread = (src->pread + avail) % src->size;
-                        todo -= avail;
-                        buf += avail;
-                }
+
+                ret = dvb_ringbuffer_read(src, buf, avail, 1);
+                if (ret < 0)
+                        break;
+
+                buf += ret;
         }
-        return count;
+
+        return (count - todo) ? (count - todo) : ret;
 }
 
 static struct dmx_frontend *get_fe(struct dmx_demux *demux, int type)
@@ -179,13 +141,12 @@ static int dvb_dvr_open(struct inode *inode, struct file *file)
         }
 
         if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
-                dvb_dmxdev_buffer_init(&dmxdev->dvr_buffer);
-                dmxdev->dvr_buffer.size = DVR_BUFFER_SIZE;
-                dmxdev->dvr_buffer.data = vmalloc(DVR_BUFFER_SIZE);
-                if (!dmxdev->dvr_buffer.data) {
+                void *mem = vmalloc(DVR_BUFFER_SIZE);
+                if (!mem) {
                         mutex_unlock(&dmxdev->mutex);
                         return -ENOMEM;
                 }
+                dvb_ringbuffer_init(&dmxdev->dvr_buffer, mem, DVR_BUFFER_SIZE);
         }
 
         if ((file->f_flags & O_ACCMODE) == O_WRONLY) {
@@ -280,7 +241,7 @@ static inline void dvb_dmxdev_filter_state_set(struct dmxdev_filter
 static int dvb_dmxdev_set_buffer_size(struct dmxdev_filter *dmxdevfilter,
                                       unsigned long size)
 {
-        struct dmxdev_buffer *buf = &dmxdevfilter->buffer;
+        struct dvb_ringbuffer *buf = &dmxdevfilter->buffer;
         void *mem;
 
         if (buf->size == size)
@@ -291,7 +252,7 @@ static int dvb_dmxdev_set_buffer_size(struct dmxdev_filter *dmxdevfilter,
         mem = buf->data;
         buf->data = NULL;
         buf->size = size;
-        buf->pwrite = buf->pread = 0;
+        dvb_ringbuffer_flush(buf);
         spin_unlock_irq(&dmxdevfilter->dev->lock);
         vfree(mem);
 
@@ -359,8 +320,8 @@ static int dvb_dmxdev_section_callback(const u8 *buffer1, size_t buffer1_len,
                                               buffer2_len);
         }
         if (ret < 0) {
-                dmxdevfilter->buffer.pwrite = dmxdevfilter->buffer.pread;
-                dmxdevfilter->buffer.error = -EOVERFLOW;
+                dvb_ringbuffer_flush(&dmxdevfilter->buffer);
+                dmxdevfilter->buffer.error = ret;
         }
         if (dmxdevfilter->params.sec.flags & DMX_ONESHOT)
                 dmxdevfilter->state = DMXDEV_STATE_DONE;
@@ -375,7 +336,7 @@ static int dvb_dmxdev_ts_callback(const u8 *buffer1, size_t buffer1_len,
                                   enum dmx_success success)
 {
         struct dmxdev_filter *dmxdevfilter = feed->priv;
-        struct dmxdev_buffer *buffer;
+        struct dvb_ringbuffer *buffer;
         int ret;
 
         spin_lock(&dmxdevfilter->dev->lock);
@@ -397,8 +358,8 @@ static int dvb_dmxdev_ts_callback(const u8 *buffer1, size_t buffer1_len,
         if (ret == buffer1_len)
                 ret = dvb_dmxdev_buffer_write(buffer, buffer2, buffer2_len);
         if (ret < 0) {
-                buffer->pwrite = buffer->pread;
-                buffer->error = -EOVERFLOW;
+                dvb_ringbuffer_flush(buffer);
+                buffer->error = ret;
         }
         spin_unlock(&dmxdevfilter->dev->lock);
         wake_up(&buffer->queue);
@@ -494,7 +455,8 @@ static int dvb_dmxdev_filter_stop(struct dmxdev_filter *dmxdevfilter)
                         return 0;
                 return -EINVAL;
         }
-        dmxdevfilter->buffer.pwrite = dmxdevfilter->buffer.pread = 0;
+
+        dvb_ringbuffer_flush(&dmxdevfilter->buffer);
         return 0;
 }
 
@@ -520,16 +482,16 @@ static int dvb_dmxdev_filter_start(struct dmxdev_filter *filter)
         if (filter->state >= DMXDEV_STATE_GO)
                 dvb_dmxdev_filter_stop(filter);
 
-        if (!(mem = filter->buffer.data)) {
+        if (!filter->buffer.data) {
                 mem = vmalloc(filter->buffer.size);
+                if (!mem)
+                        return -ENOMEM;
                 spin_lock_irq(&filter->dev->lock);
                 filter->buffer.data = mem;
                 spin_unlock_irq(&filter->dev->lock);
-                if (!filter->buffer.data)
-                        return -ENOMEM;
         }
 
-        filter->buffer.pwrite = filter->buffer.pread = 0;
+        dvb_ringbuffer_flush(&filter->buffer);
 
         switch (filter->type) {
         case DMXDEV_TYPE_SEC:
@@ -692,7 +654,7 @@ static int dvb_demux_open(struct inode *inode, struct file *file)
         mutex_init(&dmxdevfilter->mutex);
         file->private_data = dmxdevfilter;
 
-        dvb_dmxdev_buffer_init(&dmxdevfilter->buffer);
+        dvb_ringbuffer_init(&dmxdevfilter->buffer, NULL, 8192);
         dmxdevfilter->type = DMXDEV_TYPE_NONE;
         dvb_dmxdev_filter_state_set(dmxdevfilter, DMXDEV_STATE_ALLOCATED);
         dmxdevfilter->feed.ts = NULL;
@@ -973,7 +935,7 @@ static unsigned int dvb_demux_poll(struct file *file, poll_table *wait)
         if (dmxdevfilter->buffer.error)
                 mask |= (POLLIN | POLLRDNORM | POLLPRI | POLLERR);
 
-        if (dmxdevfilter->buffer.pread != dmxdevfilter->buffer.pwrite)
+        if (!dvb_ringbuffer_empty(&dmxdevfilter->buffer))
                 mask |= (POLLIN | POLLRDNORM | POLLPRI);
 
         return mask;
@@ -1047,7 +1009,7 @@ static unsigned int dvb_dvr_poll(struct file *file, poll_table *wait)
                 if (dmxdev->dvr_buffer.error)
                         mask |= (POLLIN | POLLRDNORM | POLLPRI | POLLERR);
 
-                if (dmxdev->dvr_buffer.pread != dmxdev->dvr_buffer.pwrite)
+                if (!dvb_ringbuffer_empty(&dmxdev->dvr_buffer))
                         mask |= (POLLIN | POLLRDNORM | POLLPRI);
         } else
                 mask |= (POLLOUT | POLLWRNORM | POLLPRI);
@@ -1097,7 +1059,7 @@ int dvb_dmxdev_init(struct dmxdev *dmxdev, struct dvb_adapter *dvb_adapter)
         dvb_register_device(dvb_adapter, &dmxdev->dvr_dvbdev, &dvbdev_dvr,
                             dmxdev, DVB_DEVICE_DVR);
 
-        dvb_dmxdev_buffer_init(&dmxdev->dvr_buffer);
+        dvb_ringbuffer_init(&dmxdev->dvr_buffer, NULL, 8192);
 
         return 0;
 }
diff --git a/drivers/media/dvb/dvb-core/dmxdev.h b/drivers/media/dvb/dvb-core/dmxdev.h
index 1b3e49bd9aa2..d2bee9ffe43c 100644
--- a/drivers/media/dvb/dvb-core/dmxdev.h
+++ b/drivers/media/dvb/dvb-core/dmxdev.h
@@ -36,6 +36,7 @@
 
 #include "dvbdev.h"
 #include "demux.h"
+#include "dvb_ringbuffer.h"
 
 enum dmxdev_type {
         DMXDEV_TYPE_NONE,
@@ -52,15 +53,6 @@ enum dmxdev_state {
         DMXDEV_STATE_TIMEDOUT
 };
 
-struct dmxdev_buffer {
-        u8 *data;
-        int size;
-        int pread;
-        int pwrite;
-        wait_queue_head_t queue;
-        int error;
-};
-
 struct dmxdev_filter {
         union {
                 struct dmx_section_filter *sec;
@@ -79,7 +71,7 @@ struct dmxdev_filter {
         enum dmxdev_type type;
         enum dmxdev_state state;
         struct dmxdev *dev;
-        struct dmxdev_buffer buffer;
+        struct dvb_ringbuffer buffer;
 
         struct mutex mutex;
 
@@ -102,7 +94,7 @@ struct dmxdev {
 #define DMXDEV_CAP_DUPLEX 1
         struct dmx_frontend *dvr_orig_fe;
 
-        struct dmxdev_buffer dvr_buffer;
+        struct dvb_ringbuffer dvr_buffer;
 #define DVR_BUFFER_SIZE (10*188*1024)
 
         struct mutex mutex;