kfifo: move struct kfifo in place

This is a new generic kernel FIFO implementation.

The current kernel fifo API is not very widely used, because it has to
many constrains.  Only 17 files in the current 2.6.31-rc5 used it.
FIFO's are like list's a very basic thing and a kfifo API which handles
the most use case would save a lot of development time and memory
resources.

I think this are the reasons why kfifo is not in use:

 - The API is to simple, important functions are missing
 - A fifo can be only allocated dynamically
 - There is a requirement of a spinlock whether you need it or not
 - There is no support for data records inside a fifo

So I decided to extend the kfifo in a more generic way without blowing up
the API to much.  The new API has the following benefits:

 - Generic usage: For kernel internal use and/or device driver.
 - Provide an API for the most use case.
 - Slim API: The whole API provides 25 functions.
 - Linux style habit.
 - DECLARE_KFIFO, DEFINE_KFIFO and INIT_KFIFO Macros
 - Direct copy_to_user from the fifo and copy_from_user into the fifo.
 - The kfifo itself is an in place member of the using data structure, this save an
   indirection access and does not waste the kernel allocator.
 - Lockless access: if only one reader and one writer is active on the fifo,
   which is the common use case, no additional locking is necessary.
 - Remove spinlock - give the user the freedom of choice what kind of locking to use if
   one is required.
 - Ability to handle records. Three type of records are supported:
   - Variable length records between 0-255 bytes, with a record size
     field of 1 bytes.
   - Variable length records between 0-65535 bytes, with a record size
     field of 2 bytes.
   - Fixed size records, which no record size field.
 - Preserve memory resource.
 - Performance!
 - Easy to use!

This patch:

Since most users want to have the kfifo as part of another object,
reorganize the code to allow including struct kfifo in another data
structure.  This requires changing the kfifo_alloc and kfifo_init
prototypes so that we pass an existing kfifo pointer into them.  This
patch changes the implementation and all existing users.

[akpm@linux-foundation.org: fix warning]
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 5 deletions

diff --git a/drivers/usb/host/fhci-sched.c b/drivers/usb/host/fhci-sched.c
index 00a29855d0c4..ff43747a614f 100644
--- a/drivers/usb/host/fhci-sched.c
+++ b/drivers/usb/host/fhci-sched.c
@@ -37,7 +37,7 @@ static void recycle_frame(struct fhci_usb *usb, struct packet *pkt)
 	pkt->info = 0;
 	pkt->priv_data = NULL;
 
-	cq_put(usb->ep0->empty_frame_Q, pkt);
+	cq_put(&usb->ep0->empty_frame_Q, pkt);
 }
 
 /* confirm submitted packet */
@@ -57,7 +57,7 @@ void fhci_transaction_confirm(struct fhci_usb *usb, struct packet *pkt)
 		if ((td->data + td->actual_len) && trans_len)
 			memcpy(td->data + td->actual_len, pkt->data,
 			       trans_len);
-		cq_put(usb->ep0->dummy_packets_Q, pkt->data);
+		cq_put(&usb->ep0->dummy_packets_Q, pkt->data);
 	}
 
 	recycle_frame(usb, pkt);
@@ -213,7 +213,7 @@ static int add_packet(struct fhci_usb *usb, struct ed *ed, struct td *td)
 	}
 
 	/* update frame object fields before transmitting */
-	pkt = cq_get(usb->ep0->empty_frame_Q);
+	pkt = cq_get(&usb->ep0->empty_frame_Q);
 	if (!pkt) {
 		fhci_dbg(usb->fhci, "there is no empty frame\n");
 		return -1;
@@ -222,7 +222,7 @@ static int add_packet(struct fhci_usb *usb, struct ed *ed, struct td *td)
 
 	pkt->info = 0;
 	if (data == NULL) {
-		data = cq_get(usb->ep0->dummy_packets_Q);
+		data = cq_get(&usb->ep0->dummy_packets_Q);
 		BUG_ON(!data);
 		pkt->info = PKT_DUMMY_PACKET;
 	}
@@ -246,7 +246,7 @@ static int add_packet(struct fhci_usb *usb, struct ed *ed, struct td *td)
 		list_del_init(&td->frame_lh);
 		td->status = USB_TD_OK;
 		if (pkt->info & PKT_DUMMY_PACKET)
-			cq_put(usb->ep0->dummy_packets_Q, pkt->data);
+			cq_put(&usb->ep0->dummy_packets_Q, pkt->data);
 		recycle_frame(usb, pkt);
 		usb->actual_frame->total_bytes -= (len + PROTOCOL_OVERHEAD);
 		fhci_err(usb->fhci, "host transaction failed\n");