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author | Stefani Seibold <stefani@seibold.net> | 2009-12-21 14:37:26 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-12-22 14:17:55 -0800 |
commit | 45465487897a1c6d508b14b904dc5777f7ec7e04 (patch) | |
tree | 935c8dae68dc793ff2f795d57cf027531475cd53 /drivers/usb | |
parent | 2ec91eec47f713e3d158ba5b28a24a85a2cf3650 (diff) | |
download | blackbird-op-linux-45465487897a1c6d508b14b904dc5777f7ec7e04.tar.gz blackbird-op-linux-45465487897a1c6d508b14b904dc5777f7ec7e04.zip |
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>
Diffstat (limited to 'drivers/usb')
-rw-r--r-- | drivers/usb/host/fhci-sched.c | 10 | ||||
-rw-r--r-- | drivers/usb/host/fhci-tds.c | 35 | ||||
-rw-r--r-- | drivers/usb/host/fhci.h | 10 | ||||
-rw-r--r-- | drivers/usb/serial/usb-serial.c | 5 |
4 files changed, 29 insertions, 31 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"); 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; diff --git a/drivers/usb/host/fhci.h b/drivers/usb/host/fhci.h index 7116284ed21a..2277428ef5d3 100644 --- a/drivers/usb/host/fhci.h +++ b/drivers/usb/host/fhci.h @@ -423,9 +423,9 @@ struct endpoint { struct usb_td __iomem *td_base; /* first TD in the ring */ struct usb_td __iomem *conf_td; /* next TD for confirm after transac */ struct usb_td __iomem *empty_td;/* next TD for new transaction req. */ - struct kfifo *empty_frame_Q; /* Empty frames list to use */ - struct kfifo *conf_frame_Q; /* frames passed to TDs,waiting for tx */ - struct kfifo *dummy_packets_Q;/* dummy packets for the CRC overun */ + struct kfifo empty_frame_Q; /* Empty frames list to use */ + struct kfifo conf_frame_Q; /* frames passed to TDs,waiting for tx */ + struct kfifo dummy_packets_Q;/* dummy packets for the CRC overun */ bool already_pushed_dummy_bd; }; @@ -493,9 +493,9 @@ static inline struct usb_hcd *fhci_to_hcd(struct fhci_hcd *fhci) } /* fifo of pointers */ -static inline struct kfifo *cq_new(int size) +static inline int cq_new(struct kfifo *fifo, int size) { - return kfifo_alloc(size * sizeof(void *), GFP_KERNEL, NULL); + return kfifo_alloc(fifo, size * sizeof(void *), GFP_KERNEL, NULL); } static inline void cq_delete(struct kfifo *kfifo) diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c index 4543f359be75..44b72d47fac2 100644 --- a/drivers/usb/serial/usb-serial.c +++ b/drivers/usb/serial/usb-serial.c @@ -939,9 +939,8 @@ int usb_serial_probe(struct usb_interface *interface, dev_err(&interface->dev, "No free urbs available\n"); goto probe_error; } - port->write_fifo = kfifo_alloc(PAGE_SIZE, GFP_KERNEL, - &port->lock); - if (IS_ERR(port->write_fifo)) + if (kfifo_alloc(&port->write_fifo, PAGE_SIZE, GFP_KERNEL, + &port->lock)) goto probe_error; buffer_size = le16_to_cpu(endpoint->wMaxPacketSize); port->bulk_out_size = buffer_size; |