From 45465487897a1c6d508b14b904dc5777f7ec7e04 Mon Sep 17 00:00:00 2001 From: Stefani Seibold Date: Mon, 21 Dec 2009 14:37:26 -0800 Subject: 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 Acked-by: Greg Kroah-Hartman Acked-by: Mauro Carvalho Chehab Acked-by: Andi Kleen Acked-by: Arnd Bergmann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/usb/host/fhci-tds.c | 35 +++++++++++++++++------------------ 1 file changed, 17 insertions(+), 18 deletions(-) (limited to 'drivers/usb/host/fhci-tds.c') diff --git a/drivers/usb/host/fhci-tds.c b/drivers/usb/host/fhci-tds.c index b40332290319..d224ab467a40 100644 --- a/drivers/usb/host/fhci-tds.c +++ b/drivers/usb/host/fhci-tds.c @@ -106,33 +106,33 @@ void fhci_ep0_free(struct fhci_usb *usb) cpm_muram_free(cpm_muram_offset(ep->td_base)); if (ep->conf_frame_Q) { - size = cq_howmany(ep->conf_frame_Q); + size = cq_howmany(&ep->conf_frame_Q); for (; size; size--) { - struct packet *pkt = cq_get(ep->conf_frame_Q); + struct packet *pkt = cq_get(&ep->conf_frame_Q); kfree(pkt); } - cq_delete(ep->conf_frame_Q); + cq_delete(&ep->conf_frame_Q); } if (ep->empty_frame_Q) { - size = cq_howmany(ep->empty_frame_Q); + size = cq_howmany(&ep->empty_frame_Q); for (; size; size--) { - struct packet *pkt = cq_get(ep->empty_frame_Q); + struct packet *pkt = cq_get(&ep->empty_frame_Q); kfree(pkt); } - cq_delete(ep->empty_frame_Q); + cq_delete(&ep->empty_frame_Q); } if (ep->dummy_packets_Q) { - size = cq_howmany(ep->dummy_packets_Q); + size = cq_howmany(&ep->dummy_packets_Q); for (; size; size--) { - u8 *buff = cq_get(ep->dummy_packets_Q); + u8 *buff = cq_get(&ep->dummy_packets_Q); kfree(buff); } - cq_delete(ep->dummy_packets_Q); + cq_delete(&ep->dummy_packets_Q); } kfree(ep); @@ -175,10 +175,9 @@ u32 fhci_create_ep(struct fhci_usb *usb, enum fhci_mem_alloc data_mem, ep->td_base = cpm_muram_addr(ep_offset); /* zero all queue pointers */ - ep->conf_frame_Q = cq_new(ring_len + 2); - ep->empty_frame_Q = cq_new(ring_len + 2); - ep->dummy_packets_Q = cq_new(ring_len + 2); - if (!ep->conf_frame_Q || !ep->empty_frame_Q || !ep->dummy_packets_Q) { + if (cq_new(&ep->conf_frame_Q, ring_len + 2) || + cq_new(&ep->empty_frame_Q, ring_len + 2) || + cq_new(&ep->dummy_packets_Q, ring_len + 2)) { err_for = "frame_queues"; goto err; } @@ -199,8 +198,8 @@ u32 fhci_create_ep(struct fhci_usb *usb, enum fhci_mem_alloc data_mem, err_for = "buffer"; goto err; } - cq_put(ep->empty_frame_Q, pkt); - cq_put(ep->dummy_packets_Q, buff); + cq_put(&ep->empty_frame_Q, pkt); + cq_put(&ep->dummy_packets_Q, buff); } /* we put the endpoint parameter RAM right behind the TD ring */ @@ -319,7 +318,7 @@ static void fhci_td_transaction_confirm(struct fhci_usb *usb) if ((buf == DUMMY2_BD_BUFFER) && !(td_status & ~TD_W)) continue; - pkt = cq_get(ep->conf_frame_Q); + pkt = cq_get(&ep->conf_frame_Q); if (!pkt) fhci_err(usb->fhci, "no frame to confirm\n"); @@ -460,9 +459,9 @@ u32 fhci_host_transaction(struct fhci_usb *usb, out_be16(&td->length, pkt->len); /* put the frame to the confirmation queue */ - cq_put(ep->conf_frame_Q, pkt); + cq_put(&ep->conf_frame_Q, pkt); - if (cq_howmany(ep->conf_frame_Q) == 1) + if (cq_howmany(&ep->conf_frame_Q) == 1) out_8(&usb->fhci->regs->usb_comm, USB_CMD_STR_FIFO); return 0; -- cgit v1.2.3