ALSA: core: Use seq_file for text proc file reads
[firefly-linux-kernel-4.4.55.git] / sound / core / info.c
index 9f404e965ea26366e6ad9ec65e4946263650fd37..8c1275f0fcbd7fd487077ea0bf1fadcc02771fcc 100644 (file)
@@ -81,66 +81,6 @@ static int snd_info_version_init(void);
 static int snd_info_version_done(void);
 static void snd_info_disconnect(struct snd_info_entry *entry);
 
-
-/* resize the proc r/w buffer */
-static int resize_info_buffer(struct snd_info_buffer *buffer,
-                             unsigned int nsize)
-{
-       char *nbuf;
-
-       nsize = PAGE_ALIGN(nsize);
-       nbuf = krealloc(buffer->buffer, nsize, GFP_KERNEL | __GFP_ZERO);
-       if (! nbuf)
-               return -ENOMEM;
-
-       buffer->buffer = nbuf;
-       buffer->len = nsize;
-       return 0;
-}
-
-/**
- * snd_iprintf - printf on the procfs buffer
- * @buffer: the procfs buffer
- * @fmt: the printf format
- *
- * Outputs the string on the procfs buffer just like printf().
- *
- * Return: The size of output string, or a negative error code.
- */
-int snd_iprintf(struct snd_info_buffer *buffer, const char *fmt, ...)
-{
-       va_list args;
-       int len, res;
-       int err = 0;
-
-       might_sleep();
-       if (buffer->stop || buffer->error)
-               return 0;
-       len = buffer->len - buffer->size;
-       va_start(args, fmt);
-       for (;;) {
-               va_list ap;
-               va_copy(ap, args);
-               res = vsnprintf(buffer->buffer + buffer->curr, len, fmt, ap);
-               va_end(ap);
-               if (res < len)
-                       break;
-               err = resize_info_buffer(buffer, buffer->len + PAGE_SIZE);
-               if (err < 0)
-                       break;
-               len = buffer->len - buffer->size;
-       }
-       va_end(args);
-
-       if (err < 0)
-               return err;
-       buffer->curr += res;
-       buffer->size += res;
-       return res;
-}
-
-EXPORT_SYMBOL(snd_iprintf);
-
 /*
 
  */
@@ -153,6 +93,37 @@ EXPORT_SYMBOL(snd_seq_root);
 struct snd_info_entry *snd_oss_root;
 #endif
 
+static int alloc_info_private(struct snd_info_entry *entry,
+                             struct snd_info_private_data **ret)
+{
+       struct snd_info_private_data *data;
+
+       if (!entry || !entry->p)
+               return -ENODEV;
+       if (!try_module_get(entry->module))
+               return -EFAULT;
+       data = kzalloc(sizeof(*data), GFP_KERNEL);
+       if (!data) {
+               module_put(entry->module);
+               return -ENOMEM;
+       }
+       data->entry = entry;
+       *ret = data;
+       return 0;
+}
+
+static bool valid_pos(loff_t pos, size_t count)
+{
+       if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
+               return false;
+       if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
+               return false;
+       return true;
+}
+
+/*
+ * file ops for binary proc files
+ */
 static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
 {
        struct snd_info_private_data *data;
@@ -162,17 +133,14 @@ static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
        data = file->private_data;
        entry = data->entry;
        mutex_lock(&entry->access);
-       if (entry->content == SNDRV_INFO_CONTENT_DATA &&
-           entry->c.ops->llseek) {
+       if (entry->c.ops->llseek) {
                offset = entry->c.ops->llseek(entry,
                                              data->file_private_data,
                                              file, offset, orig);
                goto out;
        }
-       if (entry->content == SNDRV_INFO_CONTENT_DATA)
-               size = entry->size;
-       else
-               size = 0;
+
+       size = entry->size;
        switch (orig) {
        case SEEK_SET:
                break;
@@ -201,45 +169,20 @@ static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
 static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
                                   size_t count, loff_t * offset)
 {
-       struct snd_info_private_data *data;
-       struct snd_info_entry *entry;
-       struct snd_info_buffer *buf;
-       size_t size = 0;
+       struct snd_info_private_data *data = file->private_data;
+       struct snd_info_entry *entry = data->entry;
+       size_t size;
        loff_t pos;
 
-       data = file->private_data;
-       if (snd_BUG_ON(!data))
-               return -ENXIO;
        pos = *offset;
-       if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
-               return -EIO;
-       if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
+       if (!valid_pos(pos, count))
                return -EIO;
-       entry = data->entry;
-       switch (entry->content) {
-       case SNDRV_INFO_CONTENT_TEXT:
-               buf = data->rbuffer;
-               if (buf == NULL)
-                       return -EIO;
-               if (pos >= buf->size)
-                       return 0;
-               size = buf->size - pos;
-               size = min(count, size);
-               if (copy_to_user(buffer, buf->buffer + pos, size))
-                       return -EFAULT;
-               break;
-       case SNDRV_INFO_CONTENT_DATA:
-               if (pos >= entry->size)
-                       return 0;
-               if (entry->c.ops->read) {
-                       size = entry->size - pos;
-                       size = min(count, size);
-                       size = entry->c.ops->read(entry,
-                                                 data->file_private_data,
-                                                 file, buffer, size, pos);
-               }
-               break;
-       }
+       if (pos >= entry->size)
+               return 0;
+       size = entry->size - pos;
+       size = min(count, size);
+       size = entry->c.ops->read(entry, data->file_private_data,
+                                 file, buffer, size, pos);
        if ((ssize_t) size > 0)
                *offset = pos + size;
        return size;
@@ -248,280 +191,259 @@ static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
 static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
                                    size_t count, loff_t * offset)
 {
-       struct snd_info_private_data *data;
-       struct snd_info_entry *entry;
-       struct snd_info_buffer *buf;
+       struct snd_info_private_data *data = file->private_data;
+       struct snd_info_entry *entry = data->entry;
        ssize_t size = 0;
        loff_t pos;
 
-       data = file->private_data;
-       if (snd_BUG_ON(!data))
-               return -ENXIO;
-       entry = data->entry;
        pos = *offset;
-       if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
+       if (!valid_pos(pos, count))
                return -EIO;
-       if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
-               return -EIO;
-       switch (entry->content) {
-       case SNDRV_INFO_CONTENT_TEXT:
-               buf = data->wbuffer;
-               if (buf == NULL)
-                       return -EIO;
-               mutex_lock(&entry->access);
-               if (pos + count >= buf->len) {
-                       if (resize_info_buffer(buf, pos + count)) {
-                               mutex_unlock(&entry->access);
-                               return -ENOMEM;
-                       }
-               }
-               if (copy_from_user(buf->buffer + pos, buffer, count)) {
-                       mutex_unlock(&entry->access);
-                       return -EFAULT;
-               }
-               buf->size = pos + count;
-               mutex_unlock(&entry->access);
-               size = count;
-               break;
-       case SNDRV_INFO_CONTENT_DATA:
-               if (entry->c.ops->write && count > 0) {
-                       size_t maxsize = entry->size - pos;
-                       count = min(count, maxsize);
-                       size = entry->c.ops->write(entry,
-                                                  data->file_private_data,
-                                                  file, buffer, count, pos);
-               }
-               break;
+       if (count > 0) {
+               size_t maxsize = entry->size - pos;
+               count = min(count, maxsize);
+               size = entry->c.ops->write(entry, data->file_private_data,
+                                          file, buffer, count, pos);
        }
-       if ((ssize_t) size > 0)
+       if (size > 0)
                *offset = pos + size;
        return size;
 }
 
-static int snd_info_entry_open(struct inode *inode, struct file *file)
+static unsigned int snd_info_entry_poll(struct file *file, poll_table *wait)
+{
+       struct snd_info_private_data *data = file->private_data;
+       struct snd_info_entry *entry = data->entry;
+       unsigned int mask = 0;
+
+       if (entry->c.ops->poll)
+               return entry->c.ops->poll(entry,
+                                         data->file_private_data,
+                                         file, wait);
+       if (entry->c.ops->read)
+               mask |= POLLIN | POLLRDNORM;
+       if (entry->c.ops->write)
+               mask |= POLLOUT | POLLWRNORM;
+       return mask;
+}
+
+static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
+                               unsigned long arg)
+{
+       struct snd_info_private_data *data = file->private_data;
+       struct snd_info_entry *entry = data->entry;
+
+       if (!entry->c.ops->ioctl)
+               return -ENOTTY;
+       return entry->c.ops->ioctl(entry, data->file_private_data,
+                                  file, cmd, arg);
+}
+
+static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
 {
+       struct inode *inode = file_inode(file);
+       struct snd_info_private_data *data;
        struct snd_info_entry *entry;
+
+       data = file->private_data;
+       if (data == NULL)
+               return 0;
+       entry = data->entry;
+       if (!entry->c.ops->mmap)
+               return -ENXIO;
+       return entry->c.ops->mmap(entry, data->file_private_data,
+                                 inode, file, vma);
+}
+
+static int snd_info_entry_open(struct inode *inode, struct file *file)
+{
+       struct snd_info_entry *entry = PDE_DATA(inode);
        struct snd_info_private_data *data;
-       struct snd_info_buffer *buffer;
        int mode, err;
 
        mutex_lock(&info_mutex);
-       entry = PDE_DATA(inode);
-       if (entry == NULL || ! entry->p) {
-               mutex_unlock(&info_mutex);
-               return -ENODEV;
-       }
-       if (!try_module_get(entry->module)) {
-               err = -EFAULT;
-               goto __error1;
-       }
+       err = alloc_info_private(entry, &data);
+       if (err < 0)
+               goto unlock;
+
        mode = file->f_flags & O_ACCMODE;
-       if (mode == O_RDONLY || mode == O_RDWR) {
-               if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
-                    entry->c.ops->read == NULL)) {
-                       err = -ENODEV;
-                       goto __error;
-               }
-       }
-       if (mode == O_WRONLY || mode == O_RDWR) {
-               if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
-                    entry->c.ops->write == NULL)) {
-                       err = -ENODEV;
-                       goto __error;
-               }
+       if (((mode == O_RDONLY || mode == O_RDWR) && !entry->c.ops->read) ||
+           ((mode == O_WRONLY || mode == O_RDWR) && !entry->c.ops->write)) {
+               err = -ENODEV;
+               goto error;
        }
-       data = kzalloc(sizeof(*data), GFP_KERNEL);
-       if (data == NULL) {
-               err = -ENOMEM;
-               goto __error;
-       }
-       data->entry = entry;
-       switch (entry->content) {
-       case SNDRV_INFO_CONTENT_TEXT:
-               if (mode == O_RDONLY || mode == O_RDWR) {
-                       buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
-                       if (buffer == NULL)
-                               goto __nomem;
-                       data->rbuffer = buffer;
-                       buffer->len = PAGE_SIZE;
-                       buffer->buffer = kzalloc(buffer->len, GFP_KERNEL);
-                       if (buffer->buffer == NULL)
-                               goto __nomem;
-               }
-               if (mode == O_WRONLY || mode == O_RDWR) {
-                       buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
-                       if (buffer == NULL)
-                               goto __nomem;
-                       data->wbuffer = buffer;
-                       buffer->len = PAGE_SIZE;
-                       buffer->buffer = kmalloc(buffer->len, GFP_KERNEL);
-                       if (buffer->buffer == NULL)
-                               goto __nomem;
-               }
-               break;
-       case SNDRV_INFO_CONTENT_DATA:   /* data */
-               if (entry->c.ops->open) {
-                       if ((err = entry->c.ops->open(entry, mode,
-                                                     &data->file_private_data)) < 0) {
-                               kfree(data);
-                               goto __error;
-                       }
-               }
-               break;
+
+       if (entry->c.ops->open) {
+               err = entry->c.ops->open(entry, mode, &data->file_private_data);
+               if (err < 0)
+                       goto error;
        }
+
        file->private_data = data;
        mutex_unlock(&info_mutex);
-       if (entry->content == SNDRV_INFO_CONTENT_TEXT &&
-           (mode == O_RDONLY || mode == O_RDWR)) {
-               if (entry->c.text.read) {
-                       mutex_lock(&entry->access);
-                       entry->c.text.read(entry, data->rbuffer);
-                       mutex_unlock(&entry->access);
-               }
-       }
        return 0;
 
- __nomem:
-       if (data->rbuffer) {
-               kfree(data->rbuffer->buffer);
-               kfree(data->rbuffer);
-       }
-       if (data->wbuffer) {
-               kfree(data->wbuffer->buffer);
-               kfree(data->wbuffer);
-       }
+ error:
        kfree(data);
-       err = -ENOMEM;
-      __error:
        module_put(entry->module);
     __error1:
unlock:
        mutex_unlock(&info_mutex);
        return err;
 }
 
 static int snd_info_entry_release(struct inode *inode, struct file *file)
 {
-       struct snd_info_entry *entry;
-       struct snd_info_private_data *data;
-       int mode;
+       struct snd_info_private_data *data = file->private_data;
+       struct snd_info_entry *entry = data->entry;
 
-       mode = file->f_flags & O_ACCMODE;
-       data = file->private_data;
-       entry = data->entry;
-       switch (entry->content) {
-       case SNDRV_INFO_CONTENT_TEXT:
-               if (data->rbuffer) {
-                       kfree(data->rbuffer->buffer);
-                       kfree(data->rbuffer);
-               }
-               if (data->wbuffer) {
-                       if (entry->c.text.write) {
-                               entry->c.text.write(entry, data->wbuffer);
-                               if (data->wbuffer->error) {
-                                       if (entry->card)
-                                               dev_warn(entry->card->dev, "info: data write error to %s (%i)\n",
-                                                        entry->name,
-                                                        data->wbuffer->error);
-                                       else
-                                               pr_warn("ALSA: info: data write error to %s (%i)\n",
-                                                       entry->name,
-                                                       data->wbuffer->error);
-                               }
-                       }
-                       kfree(data->wbuffer->buffer);
-                       kfree(data->wbuffer);
-               }
-               break;
-       case SNDRV_INFO_CONTENT_DATA:
-               if (entry->c.ops->release)
-                       entry->c.ops->release(entry, mode,
-                                             data->file_private_data);
-               break;
-       }
+       if (entry->c.ops->release)
+               entry->c.ops->release(entry, file->f_flags & O_ACCMODE,
+                                     data->file_private_data);
        module_put(entry->module);
        kfree(data);
        return 0;
 }
 
-static unsigned int snd_info_entry_poll(struct file *file, poll_table * wait)
+static const struct file_operations snd_info_entry_operations =
 {
-       struct snd_info_private_data *data;
-       struct snd_info_entry *entry;
-       unsigned int mask;
+       .owner =                THIS_MODULE,
+       .llseek =               snd_info_entry_llseek,
+       .read =                 snd_info_entry_read,
+       .write =                snd_info_entry_write,
+       .poll =                 snd_info_entry_poll,
+       .unlocked_ioctl =       snd_info_entry_ioctl,
+       .mmap =                 snd_info_entry_mmap,
+       .open =                 snd_info_entry_open,
+       .release =              snd_info_entry_release,
+};
 
-       data = file->private_data;
-       if (data == NULL)
-               return 0;
-       entry = data->entry;
-       mask = 0;
-       switch (entry->content) {
-       case SNDRV_INFO_CONTENT_DATA:
-               if (entry->c.ops->poll)
-                       return entry->c.ops->poll(entry,
-                                                 data->file_private_data,
-                                                 file, wait);
-               if (entry->c.ops->read)
-                       mask |= POLLIN | POLLRDNORM;
-               if (entry->c.ops->write)
-                       mask |= POLLOUT | POLLWRNORM;
-               break;
+/*
+ * file ops for text proc files
+ */
+static ssize_t snd_info_text_entry_write(struct file *file,
+                                        const char __user *buffer,
+                                        size_t count, loff_t *offset)
+{
+       struct seq_file *m = file->private_data;
+       struct snd_info_private_data *data = m->private;
+       struct snd_info_entry *entry = data->entry;
+       struct snd_info_buffer *buf;
+       loff_t pos;
+       size_t next;
+       int err = 0;
+
+       pos = *offset;
+       if (!valid_pos(pos, count))
+               return -EIO;
+       next = pos + count;
+       mutex_lock(&entry->access);
+       buf = data->wbuffer;
+       if (!buf) {
+               data->wbuffer = buf = kzalloc(sizeof(*buf), GFP_KERNEL);
+               if (!buf) {
+                       err = -ENOMEM;
+                       goto error;
+               }
        }
-       return mask;
+       if (next > buf->len) {
+               char *nbuf = krealloc(buf->buffer, PAGE_ALIGN(next),
+                                     GFP_KERNEL | __GFP_ZERO);
+               if (!nbuf) {
+                       err = -ENOMEM;
+                       goto error;
+               }
+               buf->buffer = nbuf;
+               buf->len = PAGE_ALIGN(next);
+       }
+       if (copy_from_user(buf->buffer + pos, buffer, count)) {
+               err = -EFAULT;
+               goto error;
+       }
+       buf->size = next;
+ error:
+       mutex_unlock(&entry->access);
+       if (err < 0)
+               return err;
+       *offset = next;
+       return count;
 }
 
-static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
-                               unsigned long arg)
+static int snd_info_seq_show(struct seq_file *seq, void *p)
 {
-       struct snd_info_private_data *data;
-       struct snd_info_entry *entry;
+       struct snd_info_private_data *data = seq->private;
+       struct snd_info_entry *entry = data->entry;
 
-       data = file->private_data;
-       if (data == NULL)
-               return 0;
-       entry = data->entry;
-       switch (entry->content) {
-       case SNDRV_INFO_CONTENT_DATA:
-               if (entry->c.ops->ioctl)
-                       return entry->c.ops->ioctl(entry,
-                                                  data->file_private_data,
-                                                  file, cmd, arg);
-               break;
+       if (entry->c.text.read) {
+               data->rbuffer->buffer = (char *)seq; /* XXX hack! */
+               entry->c.text.read(entry, data->rbuffer);
        }
-       return -ENOTTY;
+       return 0;
 }
 
-static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
+static int snd_info_text_entry_open(struct inode *inode, struct file *file)
 {
-       struct inode *inode = file_inode(file);
+       struct snd_info_entry *entry = PDE_DATA(inode);
        struct snd_info_private_data *data;
-       struct snd_info_entry *entry;
+       int err;
 
-       data = file->private_data;
-       if (data == NULL)
-               return 0;
-       entry = data->entry;
-       switch (entry->content) {
-       case SNDRV_INFO_CONTENT_DATA:
-               if (entry->c.ops->mmap)
-                       return entry->c.ops->mmap(entry,
-                                                 data->file_private_data,
-                                                 inode, file, vma);
-               break;
+       mutex_lock(&info_mutex);
+       err = alloc_info_private(entry, &data);
+       if (err < 0)
+               goto unlock;
+
+       data->rbuffer = kzalloc(sizeof(*data->rbuffer), GFP_KERNEL);
+       if (!data->rbuffer) {
+               err = -ENOMEM;
+               goto error;
+       }
+       if (entry->size)
+               err = single_open_size(file, snd_info_seq_show, data,
+                                      entry->size);
+       else
+               err = single_open(file, snd_info_seq_show, data);
+       if (err < 0)
+               goto error;
+       mutex_unlock(&info_mutex);
+       return 0;
+
+ error:
+       kfree(data->rbuffer);
+       kfree(data);
+       module_put(entry->module);
+ unlock:
+       mutex_unlock(&info_mutex);
+       return err;
+}
+
+static int snd_info_text_entry_release(struct inode *inode, struct file *file)
+{
+       struct seq_file *m = file->private_data;
+       struct snd_info_private_data *data = m->private;
+       struct snd_info_entry *entry = data->entry;
+
+       if (data->wbuffer && entry->c.text.write)
+               entry->c.text.write(entry, data->wbuffer);
+
+       single_release(inode, file);
+       kfree(data->rbuffer);
+       if (data->wbuffer) {
+               kfree(data->wbuffer->buffer);
+               kfree(data->wbuffer);
        }
-       return -ENXIO;
+
+       module_put(entry->module);
+       kfree(data);
+       return 0;
 }
 
-static const struct file_operations snd_info_entry_operations =
+static const struct file_operations snd_info_text_entry_ops =
 {
        .owner =                THIS_MODULE,
-       .llseek =               snd_info_entry_llseek,
-       .read =                 snd_info_entry_read,
-       .write =                snd_info_entry_write,
-       .poll =                 snd_info_entry_poll,
-       .unlocked_ioctl =       snd_info_entry_ioctl,
-       .mmap =                 snd_info_entry_mmap,
-       .open =                 snd_info_entry_open,
-       .release =              snd_info_entry_release,
+       .open =                 snd_info_text_entry_open,
+       .release =              snd_info_text_entry_release,
+       .write =                snd_info_text_entry_write,
+       .llseek =               seq_lseek,
+       .read =                 seq_read,
 };
 
 int __init snd_info_init(void)
@@ -955,8 +877,13 @@ int snd_info_register(struct snd_info_entry * entry)
                        return -ENOMEM;
                }
        } else {
+               const struct file_operations *ops;
+               if (entry->content == SNDRV_INFO_CONTENT_DATA)
+                       ops = &snd_info_entry_operations;
+               else
+                       ops = &snd_info_text_entry_ops;
                p = proc_create_data(entry->name, entry->mode, root,
-                                       &snd_info_entry_operations, entry);
+                                    ops, entry);
                if (!p) {
                        mutex_unlock(&info_mutex);
                        return -ENOMEM;