tty: Merge tty_buffer_find() into tty_buffer_alloc()

tty_buffer_find() implements a simple free list lookaside cache.
Merge this functionality into tty_buffer_alloc() to reflect the
more traditional alloc/free symmetry.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 18 insertions, 32 deletions

diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index 56d460295c87..a428fa2f7259 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -64,6 +64,8 @@ void tty_buffer_free_all(struct tty_port *port)
  *      @size: desired size (characters)
  *
  *      Allocate a new tty buffer to hold the desired number of characters.
+ *      We round our buffers off in 256 character chunks to get better
+ *      allocation behaviour.
  *      Return NULL if out of memory or the allocation would exceed the
  *      per device queue
  *
@@ -72,14 +74,29 @@ void tty_buffer_free_all(struct tty_port *port)
 
 static struct tty_buffer *tty_buffer_alloc(struct tty_port *port, size_t size)
 {
+        struct tty_buffer **tbh = &port->buf.free;
         struct tty_buffer *p;
 
+        /* Round the buffer size out */
+        size = __ALIGN_MASK(size, TTYB_ALIGN_MASK);
+
+        if (size <= MIN_TTYB_SIZE) {
+                if (*tbh) {
+                        p = *tbh;
+                        *tbh = p->next;
+                        goto found;
+                }
+        }
+
+        /* Should possibly check if this fails for the largest buffer we
+           have queued and recycle that ? */
         if (port->buf.memory_used + size > 65536)
                 return NULL;
         p = kmalloc(sizeof(struct tty_buffer) + 2 * size, GFP_ATOMIC);
         if (p == NULL)
                 return NULL;
 
+found:
         tty_buffer_reset(p, size);
         port->buf.memory_used += size;
         return p;
@@ -172,37 +189,6 @@ void tty_buffer_flush(struct tty_struct *tty)
 }
 
 /**
- *      tty_buffer_find         -       find a free tty buffer
- *      @tty: tty owning the buffer
- *      @size: characters wanted
- *
- *      Locate an existing suitable tty buffer or if we are lacking one then
- *      allocate a new one. We round our buffers off in 256 character chunks
- *      to get better allocation behaviour.
- *
- *      Locking: Caller must hold tty->buf.lock
- */
-
-static struct tty_buffer *tty_buffer_find(struct tty_port *port, size_t size)
-{
-        struct tty_buffer **tbh = &port->buf.free;
-        if (size <= MIN_TTYB_SIZE) {
-                if (*tbh) {
-                        struct tty_buffer *t = *tbh;
-
-                        *tbh = t->next;
-                        tty_buffer_reset(t, t->size);
-                        port->buf.memory_used += t->size;
-                        return t;
-                }
-        }
-        /* Round the buffer size out */
-        size = __ALIGN_MASK(size, TTYB_ALIGN_MASK);
-        return tty_buffer_alloc(port, size);
-        /* Should possibly check if this fails for the largest buffer we
-           have queued and recycle that ? */
-}
-/**
  *      tty_buffer_request_room         -       grow tty buffer if needed
  *      @tty: tty structure
  *      @size: size desired
@@ -230,7 +216,7 @@ int tty_buffer_request_room(struct tty_port *port, size_t size)
 
         if (left < size) {
                 /* This is the slow path - looking for new buffers to use */
-                if ((n = tty_buffer_find(port, size)) != NULL) {
+                if ((n = tty_buffer_alloc(port, size)) != NULL) {
                         if (b != NULL) {
                                 b->next = n;
                                 b->commit = b->used;