From 67cccfe17d1b3da1ed6c79e643c9be95ebde9642 Mon Sep 17 00:00:00 2001 From: Eric Lapuyade Date: Thu, 13 Sep 2012 17:10:00 +0200 Subject: NFC: Add an LLC Core layer to HCI The LLC layer manages modules that control the link layer protocol (such as shdlc) between HCI and an HCI driver. The driver must simply specify the required llc when it registers with HCI. Signed-off-by: Eric Lapuyade Signed-off-by: Samuel Ortiz --- net/nfc/hci/llc.c | 168 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 168 insertions(+) create mode 100644 net/nfc/hci/llc.c (limited to 'net/nfc/hci/llc.c') diff --git a/net/nfc/hci/llc.c b/net/nfc/hci/llc.c new file mode 100644 index 000000000000..73c42785ce84 --- /dev/null +++ b/net/nfc/hci/llc.c @@ -0,0 +1,168 @@ +/* + * Link Layer Control manager + * + * Copyright (C) 2012 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the + * Free Software Foundation, Inc., + * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +#include +#include +#include "llc.h" + +static struct list_head llc_engines; + +int nfc_llc_init(void) +{ + INIT_LIST_HEAD(&llc_engines); + + return 0; +} +EXPORT_SYMBOL(nfc_llc_init); + +void nfc_llc_exit(void) +{ + struct nfc_llc_engine *llc_engine, *n; + + list_for_each_entry_safe(llc_engine, n, &llc_engines, entry) { + list_del(&llc_engine->entry); + kfree(llc_engine->name); + kfree(llc_engine); + } +} +EXPORT_SYMBOL(nfc_llc_exit); + +int nfc_llc_register(const char *name, struct nfc_llc_ops *ops) +{ + struct nfc_llc_engine *llc_engine; + + llc_engine = kzalloc(sizeof(struct nfc_llc_engine), GFP_KERNEL); + if (llc_engine == NULL) + return -ENOMEM; + + llc_engine->name = kstrdup(name, GFP_KERNEL); + if (llc_engine->name == NULL) { + kfree(llc_engine); + return -ENOMEM; + } + llc_engine->ops = ops; + + INIT_LIST_HEAD(&llc_engine->entry); + list_add_tail (&llc_engine->entry, &llc_engines); + + return 0; +} +EXPORT_SYMBOL(nfc_llc_register); + +static struct nfc_llc_engine *nfc_llc_name_to_engine(const char *name) +{ + struct nfc_llc_engine *llc_engine; + + list_for_each_entry(llc_engine, &llc_engines, entry) { + if (strcmp(llc_engine->name, name) == 0) + return llc_engine; + } + + return NULL; +} + +void nfc_llc_unregister(const char *name) +{ + struct nfc_llc_engine *llc_engine; + + llc_engine = nfc_llc_name_to_engine(name); + if (llc_engine == NULL) + return; + + list_del(&llc_engine->entry); + kfree(llc_engine->name); + kfree(llc_engine); +} +EXPORT_SYMBOL(nfc_llc_unregister); + +struct nfc_llc *nfc_llc_allocate(const char *name, struct nfc_hci_dev *hdev, + xmit_to_drv_t xmit_to_drv, + rcv_to_hci_t rcv_to_hci, int tx_headroom, + int tx_tailroom, llc_failure_t llc_failure) +{ + struct nfc_llc_engine *llc_engine; + struct nfc_llc *llc; + + llc_engine = nfc_llc_name_to_engine(name); + if (llc_engine == NULL) + return NULL; + + llc = kzalloc(sizeof(struct nfc_llc), GFP_KERNEL); + if (llc == NULL) + return NULL; + + llc->data = llc_engine->ops->init(hdev, xmit_to_drv, rcv_to_hci, + tx_headroom, tx_tailroom, + &llc->rx_headroom, &llc->rx_tailroom, + llc_failure); + if (llc->data == NULL) { + kfree(llc); + return NULL; + } + llc->ops = llc_engine->ops; + + return llc; +} +EXPORT_SYMBOL(nfc_llc_allocate); + +void nfc_llc_free(struct nfc_llc *llc) +{ + llc->ops->deinit(llc); + kfree(llc); +} +EXPORT_SYMBOL(nfc_llc_free); + +inline void nfc_llc_get_rx_head_tail_room(struct nfc_llc *llc, int *rx_headroom, + int *rx_tailroom) +{ + *rx_headroom = llc->rx_headroom; + *rx_tailroom = llc->rx_tailroom; +} +EXPORT_SYMBOL(nfc_llc_get_rx_head_tail_room); + +inline int nfc_llc_start(struct nfc_llc *llc) +{ + return llc->ops->start(llc); +} +EXPORT_SYMBOL(nfc_llc_start); + +inline int nfc_llc_stop(struct nfc_llc *llc) +{ + return llc->ops->stop(llc); +} +EXPORT_SYMBOL(nfc_llc_stop); + +inline void nfc_llc_rcv_from_drv(struct nfc_llc *llc, struct sk_buff *skb) +{ + llc->ops->rcv_from_drv(llc, skb); +} +EXPORT_SYMBOL(nfc_llc_rcv_from_drv); + +inline int nfc_llc_xmit_from_hci(struct nfc_llc *llc, struct sk_buff *skb) +{ + return llc->ops->xmit_from_hci(llc, skb); +} +EXPORT_SYMBOL(nfc_llc_xmit_from_hci); + +inline void *nfc_llc_get_data(struct nfc_llc *llc) +{ + return llc->data; +} +EXPORT_SYMBOL(nfc_llc_get_data); -- cgit v1.2.3 From 8af00d48dc929442644bf68e9cd3d951d9697296 Mon Sep 17 00:00:00 2001 From: Eric Lapuyade Date: Thu, 13 Sep 2012 17:10:48 +0200 Subject: NFC: Add a nop (passthrough) llc module to llc core This is a passthrough llc. It can be used by HCI drivers that don't need link layer control. HCI will then write directly to the driver, and driver will deliver incoming frames directly to HCI without any processing. Signed-off-by: Eric Lapuyade Signed-off-by: Samuel Ortiz --- include/net/nfc/llc.h | 2 + net/nfc/hci/Makefile | 2 +- net/nfc/hci/llc.c | 2 +- net/nfc/hci/llc.h | 2 + net/nfc/hci/llc_nop.c | 101 ++++++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 107 insertions(+), 2 deletions(-) create mode 100644 net/nfc/hci/llc_nop.c (limited to 'net/nfc/hci/llc.c') diff --git a/include/net/nfc/llc.h b/include/net/nfc/llc.h index 98df903f8b7d..146e053f91e7 100644 --- a/include/net/nfc/llc.h +++ b/include/net/nfc/llc.h @@ -24,6 +24,8 @@ #include #include +#define LLC_NOP_NAME "nop" + typedef void (*rcv_to_hci_t) (struct nfc_hci_dev *hdev, struct sk_buff *skb); typedef int (*xmit_to_drv_t) (struct nfc_hci_dev *hdev, struct sk_buff *skb); typedef void (*llc_failure_t) (struct nfc_hci_dev *hdev, int err); diff --git a/net/nfc/hci/Makefile b/net/nfc/hci/Makefile index b44686b581af..2ec4e5876f6b 100644 --- a/net/nfc/hci/Makefile +++ b/net/nfc/hci/Makefile @@ -4,5 +4,5 @@ obj-$(CONFIG_NFC_HCI) += hci.o -hci-y := core.o hcp.o command.o llc.o +hci-y := core.o hcp.o command.o llc.o llc_nop.o hci-$(CONFIG_NFC_SHDLC) += shdlc.o diff --git a/net/nfc/hci/llc.c b/net/nfc/hci/llc.c index 73c42785ce84..32002e5339c0 100644 --- a/net/nfc/hci/llc.c +++ b/net/nfc/hci/llc.c @@ -28,7 +28,7 @@ int nfc_llc_init(void) { INIT_LIST_HEAD(&llc_engines); - return 0; + return nfc_llc_nop_register(); } EXPORT_SYMBOL(nfc_llc_init); diff --git a/net/nfc/hci/llc.h b/net/nfc/hci/llc.h index b2c7285b0309..acdd8d1bbae5 100644 --- a/net/nfc/hci/llc.h +++ b/net/nfc/hci/llc.h @@ -55,4 +55,6 @@ void *nfc_llc_get_data(struct nfc_llc *llc); int nfc_llc_register(const char *name, struct nfc_llc_ops *ops); void nfc_llc_unregister(const char *name); +int nfc_llc_nop_register(void); + #endif /* __LOCAL_LLC_H_ */ diff --git a/net/nfc/hci/llc_nop.c b/net/nfc/hci/llc_nop.c new file mode 100644 index 000000000000..ec627cee12cd --- /dev/null +++ b/net/nfc/hci/llc_nop.c @@ -0,0 +1,101 @@ +/* + * nop (passthrough) Link Layer Control + * + * Copyright (C) 2012 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the + * Free Software Foundation, Inc., + * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +#include +#include + +#include "llc.h" + +struct llc_nop { + struct nfc_hci_dev *hdev; + xmit_to_drv_t xmit_to_drv; + rcv_to_hci_t rcv_to_hci; + int tx_headroom; + int tx_tailroom; + llc_failure_t llc_failure; +}; + +static void *llc_nop_init(struct nfc_hci_dev *hdev, xmit_to_drv_t xmit_to_drv, + rcv_to_hci_t rcv_to_hci, int tx_headroom, + int tx_tailroom, int *rx_headroom, int *rx_tailroom, + llc_failure_t llc_failure) +{ + struct llc_nop *llc_nop; + + *rx_headroom = 0; + *rx_tailroom = 0; + + llc_nop = kzalloc(sizeof(struct llc_nop), GFP_KERNEL); + if (llc_nop == NULL) + return NULL; + + llc_nop->hdev = hdev; + llc_nop->xmit_to_drv = xmit_to_drv; + llc_nop->rcv_to_hci = rcv_to_hci; + llc_nop->tx_headroom = tx_headroom; + llc_nop->tx_tailroom = tx_tailroom; + llc_nop->llc_failure = llc_failure; + + return llc_nop; +} + +static void llc_nop_deinit(struct nfc_llc *llc) +{ + kfree(nfc_llc_get_data(llc)); +} + +static int llc_nop_start(struct nfc_llc *llc) +{ + return 0; +} + +static int llc_nop_stop(struct nfc_llc *llc) +{ + return 0; +} + +static void llc_nop_rcv_from_drv(struct nfc_llc *llc, struct sk_buff *skb) +{ + struct llc_nop *llc_nop = nfc_llc_get_data(llc); + + llc_nop->rcv_to_hci(llc_nop->hdev, skb); +} + +static int llc_nop_xmit_from_hci(struct nfc_llc *llc, struct sk_buff *skb) +{ + struct llc_nop *llc_nop = nfc_llc_get_data(llc); + + return llc_nop->xmit_to_drv(llc_nop->hdev, skb); +} + +static struct nfc_llc_ops llc_nop_ops = { + .init = llc_nop_init, + .deinit = llc_nop_deinit, + .start = llc_nop_start, + .stop = llc_nop_stop, + .rcv_from_drv = llc_nop_rcv_from_drv, + .xmit_from_hci = llc_nop_xmit_from_hci, +}; + +int nfc_llc_nop_register() +{ + return nfc_llc_register(LLC_NOP_NAME, &llc_nop_ops); +} +EXPORT_SYMBOL(nfc_llc_nop_register); -- cgit v1.2.3 From 4a61cd6687fc6348d08724676d34e38160d6cf9b Mon Sep 17 00:00:00 2001 From: Eric Lapuyade Date: Thu, 13 Sep 2012 17:11:37 +0200 Subject: NFC: Add an shdlc llc module to llc core This is used by HCI drivers such as the one for the pn544 which require communications between HCI and the chip to use shdlc. Signed-off-by: Eric Lapuyade Signed-off-by: Samuel Ortiz --- include/net/nfc/llc.h | 1 + net/nfc/hci/Makefile | 2 +- net/nfc/hci/llc.c | 16 +- net/nfc/hci/llc.h | 1 + net/nfc/hci/llc_shdlc.c | 834 ++++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 852 insertions(+), 2 deletions(-) create mode 100644 net/nfc/hci/llc_shdlc.c (limited to 'net/nfc/hci/llc.c') diff --git a/include/net/nfc/llc.h b/include/net/nfc/llc.h index 146e053f91e7..400ab7ae749d 100644 --- a/include/net/nfc/llc.h +++ b/include/net/nfc/llc.h @@ -25,6 +25,7 @@ #include #define LLC_NOP_NAME "nop" +#define LLC_SHDLC_NAME "shdlc" typedef void (*rcv_to_hci_t) (struct nfc_hci_dev *hdev, struct sk_buff *skb); typedef int (*xmit_to_drv_t) (struct nfc_hci_dev *hdev, struct sk_buff *skb); diff --git a/net/nfc/hci/Makefile b/net/nfc/hci/Makefile index 2ec4e5876f6b..c4d65479629b 100644 --- a/net/nfc/hci/Makefile +++ b/net/nfc/hci/Makefile @@ -5,4 +5,4 @@ obj-$(CONFIG_NFC_HCI) += hci.o hci-y := core.o hcp.o command.o llc.o llc_nop.o -hci-$(CONFIG_NFC_SHDLC) += shdlc.o +hci-$(CONFIG_NFC_SHDLC) += shdlc.o llc_shdlc.o diff --git a/net/nfc/hci/llc.c b/net/nfc/hci/llc.c index 32002e5339c0..bd11b0f7658a 100644 --- a/net/nfc/hci/llc.c +++ b/net/nfc/hci/llc.c @@ -26,9 +26,23 @@ static struct list_head llc_engines; int nfc_llc_init(void) { + int r; + INIT_LIST_HEAD(&llc_engines); - return nfc_llc_nop_register(); + r = nfc_llc_nop_register(); + if (r) + goto exit; + + r = nfc_llc_shdlc_register(); + if (r) + goto exit; + + return 0; + +exit: + nfc_llc_exit(); + return r; } EXPORT_SYMBOL(nfc_llc_init); diff --git a/net/nfc/hci/llc.h b/net/nfc/hci/llc.h index acdd8d1bbae5..c7014fdfc8c9 100644 --- a/net/nfc/hci/llc.h +++ b/net/nfc/hci/llc.h @@ -56,5 +56,6 @@ int nfc_llc_register(const char *name, struct nfc_llc_ops *ops); void nfc_llc_unregister(const char *name); int nfc_llc_nop_register(void); +int nfc_llc_shdlc_register(void); #endif /* __LOCAL_LLC_H_ */ diff --git a/net/nfc/hci/llc_shdlc.c b/net/nfc/hci/llc_shdlc.c new file mode 100644 index 000000000000..bb191100ee96 --- /dev/null +++ b/net/nfc/hci/llc_shdlc.c @@ -0,0 +1,834 @@ +/* + * shdlc Link Layer Control + * + * Copyright (C) 2012 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the + * Free Software Foundation, Inc., + * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +#define pr_fmt(fmt) "shdlc: %s: " fmt, __func__ + +#include +#include +#include +#include +#include +#include + +#include "llc.h" + +enum shdlc_state { + SHDLC_DISCONNECTED = 0, + SHDLC_CONNECTING = 1, + SHDLC_NEGOCIATING = 2, + SHDLC_CONNECTED = 3 +}; + +struct llc_shdlc { + struct nfc_hci_dev *hdev; + xmit_to_drv_t xmit_to_drv; + rcv_to_hci_t rcv_to_hci; + + struct mutex state_mutex; + enum shdlc_state state; + int hard_fault; + + wait_queue_head_t *connect_wq; + int connect_tries; + int connect_result; + struct timer_list connect_timer;/* aka T3 in spec 10.6.1 */ + + u8 w; /* window size */ + bool srej_support; + + struct timer_list t1_timer; /* send ack timeout */ + bool t1_active; + + struct timer_list t2_timer; /* guard/retransmit timeout */ + bool t2_active; + + int ns; /* next seq num for send */ + int nr; /* next expected seq num for receive */ + int dnr; /* oldest sent unacked seq num */ + + struct sk_buff_head rcv_q; + + struct sk_buff_head send_q; + bool rnr; /* other side is not ready to receive */ + + struct sk_buff_head ack_pending_q; + + struct work_struct sm_work; + + int tx_headroom; + int tx_tailroom; + + llc_failure_t llc_failure; +}; + +#define SHDLC_LLC_HEAD_ROOM 2 + +#define SHDLC_MAX_WINDOW 4 +#define SHDLC_SREJ_SUPPORT false + +#define SHDLC_CONTROL_HEAD_MASK 0xe0 +#define SHDLC_CONTROL_HEAD_I 0x80 +#define SHDLC_CONTROL_HEAD_I2 0xa0 +#define SHDLC_CONTROL_HEAD_S 0xc0 +#define SHDLC_CONTROL_HEAD_U 0xe0 + +#define SHDLC_CONTROL_NS_MASK 0x38 +#define SHDLC_CONTROL_NR_MASK 0x07 +#define SHDLC_CONTROL_TYPE_MASK 0x18 + +#define SHDLC_CONTROL_M_MASK 0x1f + +enum sframe_type { + S_FRAME_RR = 0x00, + S_FRAME_REJ = 0x01, + S_FRAME_RNR = 0x02, + S_FRAME_SREJ = 0x03 +}; + +enum uframe_modifier { + U_FRAME_UA = 0x06, + U_FRAME_RSET = 0x19 +}; + +#define SHDLC_CONNECT_VALUE_MS 5 +#define SHDLC_T1_VALUE_MS(w) ((5 * w) / 4) +#define SHDLC_T2_VALUE_MS 300 + +#define SHDLC_DUMP_SKB(info, skb) \ +do { \ + pr_debug("%s:\n", info); \ + print_hex_dump(KERN_DEBUG, "shdlc: ", DUMP_PREFIX_OFFSET, \ + 16, 1, skb->data, skb->len, 0); \ +} while (0) + +/* checks x < y <= z modulo 8 */ +static bool llc_shdlc_x_lt_y_lteq_z(int x, int y, int z) +{ + if (x < z) + return ((x < y) && (y <= z)) ? true : false; + else + return ((y > x) || (y <= z)) ? true : false; +} + +/* checks x <= y < z modulo 8 */ +static bool llc_shdlc_x_lteq_y_lt_z(int x, int y, int z) +{ + if (x <= z) + return ((x <= y) && (y < z)) ? true : false; + else /* x > z -> z+8 > x */ + return ((y >= x) || (y < z)) ? true : false; +} + +static struct sk_buff *llc_shdlc_alloc_skb(struct llc_shdlc *shdlc, + int payload_len) +{ + struct sk_buff *skb; + + skb = alloc_skb(shdlc->tx_headroom + SHDLC_LLC_HEAD_ROOM + + shdlc->tx_tailroom + payload_len, GFP_KERNEL); + if (skb) + skb_reserve(skb, shdlc->tx_headroom + SHDLC_LLC_HEAD_ROOM); + + return skb; +} + +/* immediately sends an S frame. */ +static int llc_shdlc_send_s_frame(struct llc_shdlc *shdlc, + enum sframe_type sframe_type, int nr) +{ + int r; + struct sk_buff *skb; + + pr_debug("sframe_type=%d nr=%d\n", sframe_type, nr); + + skb = llc_shdlc_alloc_skb(shdlc, 0); + if (skb == NULL) + return -ENOMEM; + + *skb_push(skb, 1) = SHDLC_CONTROL_HEAD_S | (sframe_type << 3) | nr; + + r = shdlc->xmit_to_drv(shdlc->hdev, skb); + + kfree_skb(skb); + + return r; +} + +/* immediately sends an U frame. skb may contain optional payload */ +static int llc_shdlc_send_u_frame(struct llc_shdlc *shdlc, + struct sk_buff *skb, + enum uframe_modifier uframe_modifier) +{ + int r; + + pr_debug("uframe_modifier=%d\n", uframe_modifier); + + *skb_push(skb, 1) = SHDLC_CONTROL_HEAD_U | uframe_modifier; + + r = shdlc->xmit_to_drv(shdlc->hdev, skb); + + kfree_skb(skb); + + return r; +} + +/* + * Free ack_pending frames until y_nr - 1, and reset t2 according to + * the remaining oldest ack_pending frame sent time + */ +static void llc_shdlc_reset_t2(struct llc_shdlc *shdlc, int y_nr) +{ + struct sk_buff *skb; + int dnr = shdlc->dnr; /* MUST initially be < y_nr */ + + pr_debug("release ack pending up to frame %d excluded\n", y_nr); + + while (dnr != y_nr) { + pr_debug("release ack pending frame %d\n", dnr); + + skb = skb_dequeue(&shdlc->ack_pending_q); + kfree_skb(skb); + + dnr = (dnr + 1) % 8; + } + + if (skb_queue_empty(&shdlc->ack_pending_q)) { + if (shdlc->t2_active) { + del_timer_sync(&shdlc->t2_timer); + shdlc->t2_active = false; + + pr_debug + ("All sent frames acked. Stopped T2(retransmit)\n"); + } + } else { + skb = skb_peek(&shdlc->ack_pending_q); + + mod_timer(&shdlc->t2_timer, *(unsigned long *)skb->cb + + msecs_to_jiffies(SHDLC_T2_VALUE_MS)); + shdlc->t2_active = true; + + pr_debug + ("Start T2(retransmit) for remaining unacked sent frames\n"); + } +} + +/* + * Receive validated frames from lower layer. skb contains HCI payload only. + * Handle according to algorithm at spec:10.8.2 + */ +static void llc_shdlc_rcv_i_frame(struct llc_shdlc *shdlc, + struct sk_buff *skb, int ns, int nr) +{ + int x_ns = ns; + int y_nr = nr; + + pr_debug("recvd I-frame %d, remote waiting frame %d\n", ns, nr); + + if (shdlc->state != SHDLC_CONNECTED) + goto exit; + + if (x_ns != shdlc->nr) { + llc_shdlc_send_s_frame(shdlc, S_FRAME_REJ, shdlc->nr); + goto exit; + } + + if (shdlc->t1_active == false) { + shdlc->t1_active = true; + mod_timer(&shdlc->t1_timer, jiffies + + msecs_to_jiffies(SHDLC_T1_VALUE_MS(shdlc->w))); + pr_debug("(re)Start T1(send ack)\n"); + } + + if (skb->len) { + shdlc->rcv_to_hci(shdlc->hdev, skb); + skb = NULL; + } + + shdlc->nr = (shdlc->nr + 1) % 8; + + if (llc_shdlc_x_lt_y_lteq_z(shdlc->dnr, y_nr, shdlc->ns)) { + llc_shdlc_reset_t2(shdlc, y_nr); + + shdlc->dnr = y_nr; + } + +exit: + kfree_skb(skb); +} + +static void llc_shdlc_rcv_ack(struct llc_shdlc *shdlc, int y_nr) +{ + pr_debug("remote acked up to frame %d excluded\n", y_nr); + + if (llc_shdlc_x_lt_y_lteq_z(shdlc->dnr, y_nr, shdlc->ns)) { + llc_shdlc_reset_t2(shdlc, y_nr); + shdlc->dnr = y_nr; + } +} + +static void llc_shdlc_requeue_ack_pending(struct llc_shdlc *shdlc) +{ + struct sk_buff *skb; + + pr_debug("ns reset to %d\n", shdlc->dnr); + + while ((skb = skb_dequeue_tail(&shdlc->ack_pending_q))) { + skb_pull(skb, 1); /* remove control field */ + skb_queue_head(&shdlc->send_q, skb); + } + shdlc->ns = shdlc->dnr; +} + +static void llc_shdlc_rcv_rej(struct llc_shdlc *shdlc, int y_nr) +{ + struct sk_buff *skb; + + pr_debug("remote asks retransmition from frame %d\n", y_nr); + + if (llc_shdlc_x_lteq_y_lt_z(shdlc->dnr, y_nr, shdlc->ns)) { + if (shdlc->t2_active) { + del_timer_sync(&shdlc->t2_timer); + shdlc->t2_active = false; + pr_debug("Stopped T2(retransmit)\n"); + } + + if (shdlc->dnr != y_nr) { + while ((shdlc->dnr = ((shdlc->dnr + 1) % 8)) != y_nr) { + skb = skb_dequeue(&shdlc->ack_pending_q); + kfree_skb(skb); + } + } + + llc_shdlc_requeue_ack_pending(shdlc); + } +} + +/* See spec RR:10.8.3 REJ:10.8.4 */ +static void llc_shdlc_rcv_s_frame(struct llc_shdlc *shdlc, + enum sframe_type s_frame_type, int nr) +{ + struct sk_buff *skb; + + if (shdlc->state != SHDLC_CONNECTED) + return; + + switch (s_frame_type) { + case S_FRAME_RR: + llc_shdlc_rcv_ack(shdlc, nr); + if (shdlc->rnr == true) { /* see SHDLC 10.7.7 */ + shdlc->rnr = false; + if (shdlc->send_q.qlen == 0) { + skb = llc_shdlc_alloc_skb(shdlc, 0); + if (skb) + skb_queue_tail(&shdlc->send_q, skb); + } + } + break; + case S_FRAME_REJ: + llc_shdlc_rcv_rej(shdlc, nr); + break; + case S_FRAME_RNR: + llc_shdlc_rcv_ack(shdlc, nr); + shdlc->rnr = true; + break; + default: + break; + } +} + +static void llc_shdlc_connect_complete(struct llc_shdlc *shdlc, int r) +{ + pr_debug("result=%d\n", r); + + del_timer_sync(&shdlc->connect_timer); + + if (r == 0) { + shdlc->ns = 0; + shdlc->nr = 0; + shdlc->dnr = 0; + + shdlc->state = SHDLC_CONNECTED; + } else { + shdlc->state = SHDLC_DISCONNECTED; + } + + shdlc->connect_result = r; + + wake_up(shdlc->connect_wq); +} + +static int llc_shdlc_connect_initiate(struct llc_shdlc *shdlc) +{ + struct sk_buff *skb; + + pr_debug("\n"); + + skb = llc_shdlc_alloc_skb(shdlc, 2); + if (skb == NULL) + return -ENOMEM; + + *skb_put(skb, 1) = SHDLC_MAX_WINDOW; + *skb_put(skb, 1) = SHDLC_SREJ_SUPPORT ? 1 : 0; + + return llc_shdlc_send_u_frame(shdlc, skb, U_FRAME_RSET); +} + +static int llc_shdlc_connect_send_ua(struct llc_shdlc *shdlc) +{ + struct sk_buff *skb; + + pr_debug("\n"); + + skb = llc_shdlc_alloc_skb(shdlc, 0); + if (skb == NULL) + return -ENOMEM; + + return llc_shdlc_send_u_frame(shdlc, skb, U_FRAME_UA); +} + +static void llc_shdlc_rcv_u_frame(struct llc_shdlc *shdlc, + struct sk_buff *skb, + enum uframe_modifier u_frame_modifier) +{ + u8 w = SHDLC_MAX_WINDOW; + bool srej_support = SHDLC_SREJ_SUPPORT; + int r; + + pr_debug("u_frame_modifier=%d\n", u_frame_modifier); + + switch (u_frame_modifier) { + case U_FRAME_RSET: + if (shdlc->state == SHDLC_NEGOCIATING) { + /* we sent RSET, but chip wants to negociate */ + if (skb->len > 0) + w = skb->data[0]; + + if (skb->len > 1) + srej_support = skb->data[1] & 0x01 ? true : + false; + + if ((w <= SHDLC_MAX_WINDOW) && + (SHDLC_SREJ_SUPPORT || (srej_support == false))) { + shdlc->w = w; + shdlc->srej_support = srej_support; + r = llc_shdlc_connect_send_ua(shdlc); + llc_shdlc_connect_complete(shdlc, r); + } + } else if (shdlc->state == SHDLC_CONNECTED) { + /* + * Chip wants to reset link. This is unexpected and + * unsupported. + */ + shdlc->hard_fault = -ECONNRESET; + } + break; + case U_FRAME_UA: + if ((shdlc->state == SHDLC_CONNECTING && + shdlc->connect_tries > 0) || + (shdlc->state == SHDLC_NEGOCIATING)) + llc_shdlc_connect_complete(shdlc, 0); + break; + default: + break; + } + + kfree_skb(skb); +} + +static void llc_shdlc_handle_rcv_queue(struct llc_shdlc *shdlc) +{ + struct sk_buff *skb; + u8 control; + int nr; + int ns; + enum sframe_type s_frame_type; + enum uframe_modifier u_frame_modifier; + + if (shdlc->rcv_q.qlen) + pr_debug("rcvQlen=%d\n", shdlc->rcv_q.qlen); + + while ((skb = skb_dequeue(&shdlc->rcv_q)) != NULL) { + control = skb->data[0]; + skb_pull(skb, 1); + switch (control & SHDLC_CONTROL_HEAD_MASK) { + case SHDLC_CONTROL_HEAD_I: + case SHDLC_CONTROL_HEAD_I2: + ns = (control & SHDLC_CONTROL_NS_MASK) >> 3; + nr = control & SHDLC_CONTROL_NR_MASK; + llc_shdlc_rcv_i_frame(shdlc, skb, ns, nr); + break; + case SHDLC_CONTROL_HEAD_S: + s_frame_type = (control & SHDLC_CONTROL_TYPE_MASK) >> 3; + nr = control & SHDLC_CONTROL_NR_MASK; + llc_shdlc_rcv_s_frame(shdlc, s_frame_type, nr); + kfree_skb(skb); + break; + case SHDLC_CONTROL_HEAD_U: + u_frame_modifier = control & SHDLC_CONTROL_M_MASK; + llc_shdlc_rcv_u_frame(shdlc, skb, u_frame_modifier); + break; + default: + pr_err("UNKNOWN Control=%d\n", control); + kfree_skb(skb); + break; + } + } +} + +static int llc_shdlc_w_used(int ns, int dnr) +{ + int unack_count; + + if (dnr <= ns) + unack_count = ns - dnr; + else + unack_count = 8 - dnr + ns; + + return unack_count; +} + +/* Send frames according to algorithm at spec:10.8.1 */ +static void llc_shdlc_handle_send_queue(struct llc_shdlc *shdlc) +{ + struct sk_buff *skb; + int r; + unsigned long time_sent; + + if (shdlc->send_q.qlen) + pr_debug + ("sendQlen=%d ns=%d dnr=%d rnr=%s w_room=%d unackQlen=%d\n", + shdlc->send_q.qlen, shdlc->ns, shdlc->dnr, + shdlc->rnr == false ? "false" : "true", + shdlc->w - llc_shdlc_w_used(shdlc->ns, shdlc->dnr), + shdlc->ack_pending_q.qlen); + + while (shdlc->send_q.qlen && shdlc->ack_pending_q.qlen < shdlc->w && + (shdlc->rnr == false)) { + + if (shdlc->t1_active) { + del_timer_sync(&shdlc->t1_timer); + shdlc->t1_active = false; + pr_debug("Stopped T1(send ack)\n"); + } + + skb = skb_dequeue(&shdlc->send_q); + + *skb_push(skb, 1) = SHDLC_CONTROL_HEAD_I | (shdlc->ns << 3) | + shdlc->nr; + + pr_debug("Sending I-Frame %d, waiting to rcv %d\n", shdlc->ns, + shdlc->nr); + /* SHDLC_DUMP_SKB("shdlc frame written", skb); */ + + r = shdlc->xmit_to_drv(shdlc->hdev, skb); + if (r < 0) { + shdlc->hard_fault = r; + break; + } + + shdlc->ns = (shdlc->ns + 1) % 8; + + time_sent = jiffies; + *(unsigned long *)skb->cb = time_sent; + + skb_queue_tail(&shdlc->ack_pending_q, skb); + + if (shdlc->t2_active == false) { + shdlc->t2_active = true; + mod_timer(&shdlc->t2_timer, time_sent + + msecs_to_jiffies(SHDLC_T2_VALUE_MS)); + pr_debug("Started T2 (retransmit)\n"); + } + } +} + +static void llc_shdlc_connect_timeout(unsigned long data) +{ + struct llc_shdlc *shdlc = (struct llc_shdlc *)data; + + pr_debug("\n"); + + queue_work(system_nrt_wq, &shdlc->sm_work); +} + +static void llc_shdlc_t1_timeout(unsigned long data) +{ + struct llc_shdlc *shdlc = (struct llc_shdlc *)data; + + pr_debug("SoftIRQ: need to send ack\n"); + + queue_work(system_nrt_wq, &shdlc->sm_work); +} + +static void llc_shdlc_t2_timeout(unsigned long data) +{ + struct llc_shdlc *shdlc = (struct llc_shdlc *)data; + + pr_debug("SoftIRQ: need to retransmit\n"); + + queue_work(system_nrt_wq, &shdlc->sm_work); +} + +static void llc_shdlc_sm_work(struct work_struct *work) +{ + struct llc_shdlc *shdlc = container_of(work, struct llc_shdlc, sm_work); + int r; + + pr_debug("\n"); + + mutex_lock(&shdlc->state_mutex); + + switch (shdlc->state) { + case SHDLC_DISCONNECTED: + skb_queue_purge(&shdlc->rcv_q); + skb_queue_purge(&shdlc->send_q); + skb_queue_purge(&shdlc->ack_pending_q); + break; + case SHDLC_CONNECTING: + if (shdlc->hard_fault) { + llc_shdlc_connect_complete(shdlc, shdlc->hard_fault); + break; + } + + if (shdlc->connect_tries++ < 5) + r = llc_shdlc_connect_initiate(shdlc); + else + r = -ETIME; + if (r < 0) + llc_shdlc_connect_complete(shdlc, r); + else { + mod_timer(&shdlc->connect_timer, jiffies + + msecs_to_jiffies(SHDLC_CONNECT_VALUE_MS)); + + shdlc->state = SHDLC_NEGOCIATING; + } + break; + case SHDLC_NEGOCIATING: + if (timer_pending(&shdlc->connect_timer) == 0) { + shdlc->state = SHDLC_CONNECTING; + queue_work(system_nrt_wq, &shdlc->sm_work); + } + + llc_shdlc_handle_rcv_queue(shdlc); + + if (shdlc->hard_fault) { + llc_shdlc_connect_complete(shdlc, shdlc->hard_fault); + break; + } + break; + case SHDLC_CONNECTED: + llc_shdlc_handle_rcv_queue(shdlc); + llc_shdlc_handle_send_queue(shdlc); + + if (shdlc->t1_active && timer_pending(&shdlc->t1_timer) == 0) { + pr_debug + ("Handle T1(send ack) elapsed (T1 now inactive)\n"); + + shdlc->t1_active = false; + r = llc_shdlc_send_s_frame(shdlc, S_FRAME_RR, + shdlc->nr); + if (r < 0) + shdlc->hard_fault = r; + } + + if (shdlc->t2_active && timer_pending(&shdlc->t2_timer) == 0) { + pr_debug + ("Handle T2(retransmit) elapsed (T2 inactive)\n"); + + shdlc->t2_active = false; + + llc_shdlc_requeue_ack_pending(shdlc); + llc_shdlc_handle_send_queue(shdlc); + } + + if (shdlc->hard_fault) { + shdlc->llc_failure(shdlc->hdev, shdlc->hard_fault); + } + break; + default: + break; + } + mutex_unlock(&shdlc->state_mutex); +} + +/* + * Called from syscall context to establish shdlc link. Sleeps until + * link is ready or failure. + */ +static int llc_shdlc_connect(struct llc_shdlc *shdlc) +{ + DECLARE_WAIT_QUEUE_HEAD_ONSTACK(connect_wq); + + pr_debug("\n"); + + mutex_lock(&shdlc->state_mutex); + + shdlc->state = SHDLC_CONNECTING; + shdlc->connect_wq = &connect_wq; + shdlc->connect_tries = 0; + shdlc->connect_result = 1; + + mutex_unlock(&shdlc->state_mutex); + + queue_work(system_nrt_wq, &shdlc->sm_work); + + wait_event(connect_wq, shdlc->connect_result != 1); + + return shdlc->connect_result; +} + +static void llc_shdlc_disconnect(struct llc_shdlc *shdlc) +{ + pr_debug("\n"); + + mutex_lock(&shdlc->state_mutex); + + shdlc->state = SHDLC_DISCONNECTED; + + mutex_unlock(&shdlc->state_mutex); + + queue_work(system_nrt_wq, &shdlc->sm_work); +} + +/* + * Receive an incoming shdlc frame. Frame has already been crc-validated. + * skb contains only LLC header and payload. + * If skb == NULL, it is a notification that the link below is dead. + */ +static void llc_shdlc_recv_frame(struct llc_shdlc *shdlc, struct sk_buff *skb) +{ + if (skb == NULL) { + pr_err("NULL Frame -> link is dead\n"); + shdlc->hard_fault = -EREMOTEIO; + } else { + SHDLC_DUMP_SKB("incoming frame", skb); + skb_queue_tail(&shdlc->rcv_q, skb); + } + + queue_work(system_nrt_wq, &shdlc->sm_work); +} + +static void *llc_shdlc_init(struct nfc_hci_dev *hdev, xmit_to_drv_t xmit_to_drv, + rcv_to_hci_t rcv_to_hci, int tx_headroom, + int tx_tailroom, int *rx_headroom, int *rx_tailroom, + llc_failure_t llc_failure) +{ + struct llc_shdlc *shdlc; + + *rx_headroom = SHDLC_LLC_HEAD_ROOM; + *rx_tailroom = 0; + + shdlc = kzalloc(sizeof(struct llc_shdlc), GFP_KERNEL); + if (shdlc == NULL) + return NULL; + + mutex_init(&shdlc->state_mutex); + shdlc->state = SHDLC_DISCONNECTED; + + init_timer(&shdlc->connect_timer); + shdlc->connect_timer.data = (unsigned long)shdlc; + shdlc->connect_timer.function = llc_shdlc_connect_timeout; + + init_timer(&shdlc->t1_timer); + shdlc->t1_timer.data = (unsigned long)shdlc; + shdlc->t1_timer.function = llc_shdlc_t1_timeout; + + init_timer(&shdlc->t2_timer); + shdlc->t2_timer.data = (unsigned long)shdlc; + shdlc->t2_timer.function = llc_shdlc_t2_timeout; + + shdlc->w = SHDLC_MAX_WINDOW; + shdlc->srej_support = SHDLC_SREJ_SUPPORT; + + skb_queue_head_init(&shdlc->rcv_q); + skb_queue_head_init(&shdlc->send_q); + skb_queue_head_init(&shdlc->ack_pending_q); + + INIT_WORK(&shdlc->sm_work, llc_shdlc_sm_work); + + shdlc->hdev = hdev; + shdlc->xmit_to_drv = xmit_to_drv; + shdlc->rcv_to_hci = rcv_to_hci; + shdlc->tx_headroom = tx_headroom; + shdlc->tx_tailroom = tx_tailroom; + shdlc->llc_failure = llc_failure; + + return shdlc; +} + +static void llc_shdlc_deinit(struct nfc_llc *llc) +{ + struct llc_shdlc *shdlc = nfc_llc_get_data(llc); + + skb_queue_purge(&shdlc->rcv_q); + skb_queue_purge(&shdlc->send_q); + skb_queue_purge(&shdlc->ack_pending_q); + + kfree(shdlc); +} + +static int llc_shdlc_start(struct nfc_llc *llc) +{ + struct llc_shdlc *shdlc = nfc_llc_get_data(llc); + + return llc_shdlc_connect(shdlc); +} + +static int llc_shdlc_stop(struct nfc_llc *llc) +{ + struct llc_shdlc *shdlc = nfc_llc_get_data(llc); + + llc_shdlc_disconnect(shdlc); + + return 0; +} + +static void llc_shdlc_rcv_from_drv(struct nfc_llc *llc, struct sk_buff *skb) +{ + struct llc_shdlc *shdlc = nfc_llc_get_data(llc); + + llc_shdlc_recv_frame(shdlc, skb); +} + +static int llc_shdlc_xmit_from_hci(struct nfc_llc *llc, struct sk_buff *skb) +{ + struct llc_shdlc *shdlc = nfc_llc_get_data(llc); + + skb_queue_tail(&shdlc->send_q, skb); + + queue_work(system_nrt_wq, &shdlc->sm_work); + + return 0; +} + +static struct nfc_llc_ops llc_shdlc_ops = { + .init = llc_shdlc_init, + .deinit = llc_shdlc_deinit, + .start = llc_shdlc_start, + .stop = llc_shdlc_stop, + .rcv_from_drv = llc_shdlc_rcv_from_drv, + .xmit_from_hci = llc_shdlc_xmit_from_hci, +}; + +int nfc_llc_shdlc_register() +{ + return nfc_llc_register(LLC_SHDLC_NAME, &llc_shdlc_ops); +} +EXPORT_SYMBOL(nfc_llc_shdlc_register); -- cgit v1.2.3 From f4f20d0650e9cd13f65b5e7f93af126b526af721 Mon Sep 17 00:00:00 2001 From: Samuel Ortiz Date: Tue, 18 Sep 2012 19:17:33 +0200 Subject: NFC: Remove unneeded LLC symbols export After fixing the LLC Makefile, we no longer need those exports. Signed-off-by: Samuel Ortiz --- net/nfc/hci/llc.c | 14 +------------- net/nfc/hci/llc_nop.c | 2 -- net/nfc/hci/llc_shdlc.c | 2 -- 3 files changed, 1 insertion(+), 17 deletions(-) (limited to 'net/nfc/hci/llc.c') diff --git a/net/nfc/hci/llc.c b/net/nfc/hci/llc.c index bd11b0f7658a..ae1205ded87f 100644 --- a/net/nfc/hci/llc.c +++ b/net/nfc/hci/llc.c @@ -18,8 +18,8 @@ * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ -#include #include + #include "llc.h" static struct list_head llc_engines; @@ -44,7 +44,6 @@ exit: nfc_llc_exit(); return r; } -EXPORT_SYMBOL(nfc_llc_init); void nfc_llc_exit(void) { @@ -56,7 +55,6 @@ void nfc_llc_exit(void) kfree(llc_engine); } } -EXPORT_SYMBOL(nfc_llc_exit); int nfc_llc_register(const char *name, struct nfc_llc_ops *ops) { @@ -78,7 +76,6 @@ int nfc_llc_register(const char *name, struct nfc_llc_ops *ops) return 0; } -EXPORT_SYMBOL(nfc_llc_register); static struct nfc_llc_engine *nfc_llc_name_to_engine(const char *name) { @@ -104,7 +101,6 @@ void nfc_llc_unregister(const char *name) kfree(llc_engine->name); kfree(llc_engine); } -EXPORT_SYMBOL(nfc_llc_unregister); struct nfc_llc *nfc_llc_allocate(const char *name, struct nfc_hci_dev *hdev, xmit_to_drv_t xmit_to_drv, @@ -134,14 +130,12 @@ struct nfc_llc *nfc_llc_allocate(const char *name, struct nfc_hci_dev *hdev, return llc; } -EXPORT_SYMBOL(nfc_llc_allocate); void nfc_llc_free(struct nfc_llc *llc) { llc->ops->deinit(llc); kfree(llc); } -EXPORT_SYMBOL(nfc_llc_free); inline void nfc_llc_get_rx_head_tail_room(struct nfc_llc *llc, int *rx_headroom, int *rx_tailroom) @@ -149,34 +143,28 @@ inline void nfc_llc_get_rx_head_tail_room(struct nfc_llc *llc, int *rx_headroom, *rx_headroom = llc->rx_headroom; *rx_tailroom = llc->rx_tailroom; } -EXPORT_SYMBOL(nfc_llc_get_rx_head_tail_room); inline int nfc_llc_start(struct nfc_llc *llc) { return llc->ops->start(llc); } -EXPORT_SYMBOL(nfc_llc_start); inline int nfc_llc_stop(struct nfc_llc *llc) { return llc->ops->stop(llc); } -EXPORT_SYMBOL(nfc_llc_stop); inline void nfc_llc_rcv_from_drv(struct nfc_llc *llc, struct sk_buff *skb) { llc->ops->rcv_from_drv(llc, skb); } -EXPORT_SYMBOL(nfc_llc_rcv_from_drv); inline int nfc_llc_xmit_from_hci(struct nfc_llc *llc, struct sk_buff *skb) { return llc->ops->xmit_from_hci(llc, skb); } -EXPORT_SYMBOL(nfc_llc_xmit_from_hci); inline void *nfc_llc_get_data(struct nfc_llc *llc) { return llc->data; } -EXPORT_SYMBOL(nfc_llc_get_data); diff --git a/net/nfc/hci/llc_nop.c b/net/nfc/hci/llc_nop.c index ec627cee12cd..d91dd66a082d 100644 --- a/net/nfc/hci/llc_nop.c +++ b/net/nfc/hci/llc_nop.c @@ -19,7 +19,6 @@ */ #include -#include #include "llc.h" @@ -98,4 +97,3 @@ int nfc_llc_nop_register() { return nfc_llc_register(LLC_NOP_NAME, &llc_nop_ops); } -EXPORT_SYMBOL(nfc_llc_nop_register); diff --git a/net/nfc/hci/llc_shdlc.c b/net/nfc/hci/llc_shdlc.c index fad6cd18d613..3761c7490a61 100644 --- a/net/nfc/hci/llc_shdlc.c +++ b/net/nfc/hci/llc_shdlc.c @@ -22,7 +22,6 @@ #include #include -#include #include #include #include @@ -831,4 +830,3 @@ int nfc_llc_shdlc_register() { return nfc_llc_register(LLC_SHDLC_NAME, &llc_shdlc_ops); } -EXPORT_SYMBOL(nfc_llc_shdlc_register); -- cgit v1.2.3