[PATCH] TTY layer buffering revamp

[powerpc.git] / include / linux / tty.h

diff --git a/include/linux/tty.h b/include/linux/tty.h
index 5744970..3787102 100644 (file)
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -51,16 +51,22 @@
  */
 #define TTY_FLIPBUF_SIZE 512
 
-struct tty_flip_buffer {
+struct tty_buffer {
+       struct tty_buffer *next;
+       char *char_buf_ptr;
+       unsigned char *flag_buf_ptr;
+       int used;
+       int size;
+       /* Data points here */
+       unsigned long data[0];
+};
+
+struct tty_bufhead {
        struct work_struct              work;
        struct semaphore pty_sem;
-       char            *char_buf_ptr;
-       unsigned char   *flag_buf_ptr;
-       int             count;
-       int             buf_num;
-       unsigned char   char_buf[2*TTY_FLIPBUF_SIZE];
-       char            flag_buf[2*TTY_FLIPBUF_SIZE];
-       unsigned char   slop[4]; /* N.B. bug overwrites buffer by 1 */
+       struct tty_buffer *head;        /* Queue head */
+       struct tty_buffer *tail;        /* Active buffer */
+       struct tty_buffer *free;        /* Free queue head */
 };
 /*
  * The pty uses char_buf and flag_buf as a contiguous buffer
@@ -186,10 +192,11 @@ struct tty_struct {
        unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1;
        unsigned char low_latency:1, warned:1;
        unsigned char ctrl_status;
+       unsigned int receive_room;      /* Bytes free for queue */
 
        struct tty_struct *link;
        struct fasync_struct *fasync;
-       struct tty_flip_buffer flip;
+       struct tty_bufhead buf;
        int max_flip_cnt;
        int alt_speed;          /* For magic substitution of 38400 bps */
        wait_queue_head_t write_wait;