diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/pipe_fs_i.h | 64 | ||||
| -rw-r--r-- | include/linux/uio.h | 4 | ||||
| -rw-r--r-- | include/linux/wait.h | 11 |
3 files changed, 69 insertions, 10 deletions
diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h index 5c626fdc10db..44f2245debda 100644 --- a/include/linux/pipe_fs_i.h +++ b/include/linux/pipe_fs_i.h @@ -30,9 +30,10 @@ struct pipe_buffer { * struct pipe_inode_info - a linux kernel pipe * @mutex: mutex protecting the whole thing * @wait: reader/writer wait point in case of empty/full pipe - * @nrbufs: the number of non-empty pipe buffers in this pipe - * @buffers: total number of buffers (should be a power of 2) - * @curbuf: the current pipe buffer entry + * @head: The point of buffer production + * @tail: The point of buffer consumption + * @max_usage: The maximum number of slots that may be used in the ring + * @ring_size: total number of buffers (should be a power of 2) * @tmp_page: cached released page * @readers: number of current readers of this pipe * @writers: number of current writers of this pipe @@ -48,7 +49,10 @@ struct pipe_buffer { struct pipe_inode_info { struct mutex mutex; wait_queue_head_t wait; - unsigned int nrbufs, curbuf, buffers; + unsigned int head; + unsigned int tail; + unsigned int max_usage; + unsigned int ring_size; unsigned int readers; unsigned int writers; unsigned int files; @@ -105,6 +109,58 @@ struct pipe_buf_operations { }; /** + * pipe_empty - Return true if the pipe is empty + * @head: The pipe ring head pointer + * @tail: The pipe ring tail pointer + */ +static inline bool pipe_empty(unsigned int head, unsigned int tail) +{ + return head == tail; +} + +/** + * pipe_occupancy - Return number of slots used in the pipe + * @head: The pipe ring head pointer + * @tail: The pipe ring tail pointer + */ +static inline unsigned int pipe_occupancy(unsigned int head, unsigned int tail) +{ + return head - tail; +} + +/** + * pipe_full - Return true if the pipe is full + * @head: The pipe ring head pointer + * @tail: The pipe ring tail pointer + * @limit: The maximum amount of slots available. + */ +static inline bool pipe_full(unsigned int head, unsigned int tail, + unsigned int limit) +{ + return pipe_occupancy(head, tail) >= limit; +} + +/** + * pipe_space_for_user - Return number of slots available to userspace + * @head: The pipe ring head pointer + * @tail: The pipe ring tail pointer + * @pipe: The pipe info structure + */ +static inline unsigned int pipe_space_for_user(unsigned int head, unsigned int tail, + struct pipe_inode_info *pipe) +{ + unsigned int p_occupancy, p_space; + + p_occupancy = pipe_occupancy(head, tail); + if (p_occupancy >= pipe->max_usage) + return 0; + p_space = pipe->ring_size - p_occupancy; + if (p_space > pipe->max_usage) + p_space = pipe->max_usage; + return p_space; +} + +/** * pipe_buf_get - get a reference to a pipe_buffer * @pipe: the pipe that the buffer belongs to * @buf: the buffer to get a reference to diff --git a/include/linux/uio.h b/include/linux/uio.h index ab5f523bc0df..9576fd8158d7 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -45,8 +45,8 @@ struct iov_iter { union { unsigned long nr_segs; struct { - int idx; - int start_idx; + unsigned int head; + unsigned int start_head; }; }; }; diff --git a/include/linux/wait.h b/include/linux/wait.h index 3eb7cae8206c..3283c8d02137 100644 --- a/include/linux/wait.h +++ b/include/linux/wait.h @@ -201,9 +201,10 @@ void __wake_up(struct wait_queue_head *wq_head, unsigned int mode, int nr, void void __wake_up_locked_key(struct wait_queue_head *wq_head, unsigned int mode, void *key); void __wake_up_locked_key_bookmark(struct wait_queue_head *wq_head, unsigned int mode, void *key, wait_queue_entry_t *bookmark); -void __wake_up_sync_key(struct wait_queue_head *wq_head, unsigned int mode, int nr, void *key); +void __wake_up_sync_key(struct wait_queue_head *wq_head, unsigned int mode, void *key); +void __wake_up_locked_sync_key(struct wait_queue_head *wq_head, unsigned int mode, void *key); void __wake_up_locked(struct wait_queue_head *wq_head, unsigned int mode, int nr); -void __wake_up_sync(struct wait_queue_head *wq_head, unsigned int mode, int nr); +void __wake_up_sync(struct wait_queue_head *wq_head, unsigned int mode); #define wake_up(x) __wake_up(x, TASK_NORMAL, 1, NULL) #define wake_up_nr(x, nr) __wake_up(x, TASK_NORMAL, nr, NULL) @@ -214,7 +215,7 @@ void __wake_up_sync(struct wait_queue_head *wq_head, unsigned int mode, int nr); #define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL) #define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL) #define wake_up_interruptible_all(x) __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL) -#define wake_up_interruptible_sync(x) __wake_up_sync((x), TASK_INTERRUPTIBLE, 1) +#define wake_up_interruptible_sync(x) __wake_up_sync((x), TASK_INTERRUPTIBLE) /* * Wakeup macros to be used to report events to the targets. @@ -228,7 +229,9 @@ void __wake_up_sync(struct wait_queue_head *wq_head, unsigned int mode, int nr); #define wake_up_interruptible_poll(x, m) \ __wake_up(x, TASK_INTERRUPTIBLE, 1, poll_to_key(m)) #define wake_up_interruptible_sync_poll(x, m) \ - __wake_up_sync_key((x), TASK_INTERRUPTIBLE, 1, poll_to_key(m)) + __wake_up_sync_key((x), TASK_INTERRUPTIBLE, poll_to_key(m)) +#define wake_up_interruptible_sync_poll_locked(x, m) \ + __wake_up_locked_sync_key((x), TASK_INTERRUPTIBLE, poll_to_key(m)) #define ___wait_cond_timeout(condition) \ ({ \ |