diff options
Diffstat (limited to 'kernel/net/caif/cfrfml.c')
| -rw-r--r-- | kernel/net/caif/cfrfml.c | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/kernel/net/caif/cfrfml.c b/kernel/net/caif/cfrfml.c new file mode 100644 index 000000000..61d7617d9 --- /dev/null +++ b/kernel/net/caif/cfrfml.c @@ -0,0 +1,302 @@ +/* + * Copyright (C) ST-Ericsson AB 2010 + * Author: Sjur Brendeland + * License terms: GNU General Public License (GPL) version 2 + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__ + +#include <linux/stddef.h> +#include <linux/spinlock.h> +#include <linux/slab.h> +#include <asm/unaligned.h> +#include <net/caif/caif_layer.h> +#include <net/caif/cfsrvl.h> +#include <net/caif/cfpkt.h> + +#define container_obj(layr) container_of(layr, struct cfrfml, serv.layer) +#define RFM_SEGMENTATION_BIT 0x01 +#define RFM_HEAD_SIZE 7 + +static int cfrfml_receive(struct cflayer *layr, struct cfpkt *pkt); +static int cfrfml_transmit(struct cflayer *layr, struct cfpkt *pkt); + +struct cfrfml { + struct cfsrvl serv; + struct cfpkt *incomplete_frm; + int fragment_size; + u8 seghead[6]; + u16 pdu_size; + /* Protects serialized processing of packets */ + spinlock_t sync; +}; + +static void cfrfml_release(struct cflayer *layer) +{ + struct cfsrvl *srvl = container_of(layer, struct cfsrvl, layer); + struct cfrfml *rfml = container_obj(&srvl->layer); + + if (rfml->incomplete_frm) + cfpkt_destroy(rfml->incomplete_frm); + + kfree(srvl); +} + +struct cflayer *cfrfml_create(u8 channel_id, struct dev_info *dev_info, + int mtu_size) +{ + int tmp; + struct cfrfml *this = kzalloc(sizeof(struct cfrfml), GFP_ATOMIC); + + if (!this) + return NULL; + + cfsrvl_init(&this->serv, channel_id, dev_info, false); + this->serv.release = cfrfml_release; + this->serv.layer.receive = cfrfml_receive; + this->serv.layer.transmit = cfrfml_transmit; + + /* Round down to closest multiple of 16 */ + tmp = (mtu_size - RFM_HEAD_SIZE - 6) / 16; + tmp *= 16; + + this->fragment_size = tmp; + spin_lock_init(&this->sync); + snprintf(this->serv.layer.name, CAIF_LAYER_NAME_SZ, + "rfm%d", channel_id); + + return &this->serv.layer; +} + +static struct cfpkt *rfm_append(struct cfrfml *rfml, char *seghead, + struct cfpkt *pkt, int *err) +{ + struct cfpkt *tmppkt; + *err = -EPROTO; + /* n-th but not last segment */ + + if (cfpkt_extr_head(pkt, seghead, 6) < 0) + return NULL; + + /* Verify correct header */ + if (memcmp(seghead, rfml->seghead, 6) != 0) + return NULL; + + tmppkt = cfpkt_append(rfml->incomplete_frm, pkt, + rfml->pdu_size + RFM_HEAD_SIZE); + + /* If cfpkt_append failes input pkts are not freed */ + *err = -ENOMEM; + if (tmppkt == NULL) + return NULL; + + *err = 0; + return tmppkt; +} + +static int cfrfml_receive(struct cflayer *layr, struct cfpkt *pkt) +{ + u8 tmp; + bool segmented; + int err; + u8 seghead[6]; + struct cfrfml *rfml; + struct cfpkt *tmppkt = NULL; + + caif_assert(layr->up != NULL); + caif_assert(layr->receive != NULL); + rfml = container_obj(layr); + spin_lock(&rfml->sync); + + err = -EPROTO; + if (cfpkt_extr_head(pkt, &tmp, 1) < 0) + goto out; + segmented = tmp & RFM_SEGMENTATION_BIT; + + if (segmented) { + if (rfml->incomplete_frm == NULL) { + /* Initial Segment */ + if (cfpkt_peek_head(pkt, rfml->seghead, 6) < 0) + goto out; + + rfml->pdu_size = get_unaligned_le16(rfml->seghead+4); + + if (cfpkt_erroneous(pkt)) + goto out; + rfml->incomplete_frm = pkt; + pkt = NULL; + } else { + + tmppkt = rfm_append(rfml, seghead, pkt, &err); + if (tmppkt == NULL) + goto out; + + if (cfpkt_erroneous(tmppkt)) + goto out; + + rfml->incomplete_frm = tmppkt; + + + if (cfpkt_erroneous(tmppkt)) + goto out; + } + err = 0; + goto out; + } + + if (rfml->incomplete_frm) { + + /* Last Segment */ + tmppkt = rfm_append(rfml, seghead, pkt, &err); + if (tmppkt == NULL) + goto out; + + if (cfpkt_erroneous(tmppkt)) + goto out; + + rfml->incomplete_frm = NULL; + pkt = tmppkt; + tmppkt = NULL; + + /* Verify that length is correct */ + err = EPROTO; + if (rfml->pdu_size != cfpkt_getlen(pkt) - RFM_HEAD_SIZE + 1) + goto out; + } + + err = rfml->serv.layer.up->receive(rfml->serv.layer.up, pkt); + +out: + + if (err != 0) { + if (tmppkt) + cfpkt_destroy(tmppkt); + if (pkt) + cfpkt_destroy(pkt); + if (rfml->incomplete_frm) + cfpkt_destroy(rfml->incomplete_frm); + rfml->incomplete_frm = NULL; + + pr_info("Connection error %d triggered on RFM link\n", err); + + /* Trigger connection error upon failure.*/ + layr->up->ctrlcmd(layr->up, CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND, + rfml->serv.dev_info.id); + } + spin_unlock(&rfml->sync); + + if (unlikely(err == -EAGAIN)) + /* It is not possible to recover after drop of a fragment */ + err = -EIO; + + return err; +} + + +static int cfrfml_transmit_segment(struct cfrfml *rfml, struct cfpkt *pkt) +{ + caif_assert(cfpkt_getlen(pkt) < rfml->fragment_size + RFM_HEAD_SIZE); + + /* Add info for MUX-layer to route the packet out. */ + cfpkt_info(pkt)->channel_id = rfml->serv.layer.id; + + /* + * To optimize alignment, we add up the size of CAIF header before + * payload. + */ + cfpkt_info(pkt)->hdr_len = RFM_HEAD_SIZE; + cfpkt_info(pkt)->dev_info = &rfml->serv.dev_info; + + return rfml->serv.layer.dn->transmit(rfml->serv.layer.dn, pkt); +} + +static int cfrfml_transmit(struct cflayer *layr, struct cfpkt *pkt) +{ + int err; + u8 seg; + u8 head[6]; + struct cfpkt *rearpkt = NULL; + struct cfpkt *frontpkt = pkt; + struct cfrfml *rfml = container_obj(layr); + + caif_assert(layr->dn != NULL); + caif_assert(layr->dn->transmit != NULL); + + if (!cfsrvl_ready(&rfml->serv, &err)) + goto out; + + err = -EPROTO; + if (cfpkt_getlen(pkt) <= RFM_HEAD_SIZE-1) + goto out; + + err = 0; + if (cfpkt_getlen(pkt) > rfml->fragment_size + RFM_HEAD_SIZE) + err = cfpkt_peek_head(pkt, head, 6); + + if (err < 0) + goto out; + + while (cfpkt_getlen(frontpkt) > rfml->fragment_size + RFM_HEAD_SIZE) { + + seg = 1; + err = -EPROTO; + + if (cfpkt_add_head(frontpkt, &seg, 1) < 0) + goto out; + /* + * On OOM error cfpkt_split returns NULL. + * + * NOTE: Segmented pdu is not correctly aligned. + * This has negative performance impact. + */ + + rearpkt = cfpkt_split(frontpkt, rfml->fragment_size); + if (rearpkt == NULL) + goto out; + + err = cfrfml_transmit_segment(rfml, frontpkt); + + if (err != 0) { + frontpkt = NULL; + goto out; + } + + frontpkt = rearpkt; + rearpkt = NULL; + + err = -ENOMEM; + if (frontpkt == NULL) + goto out; + err = -EPROTO; + if (cfpkt_add_head(frontpkt, head, 6) < 0) + goto out; + + } + + seg = 0; + err = -EPROTO; + + if (cfpkt_add_head(frontpkt, &seg, 1) < 0) + goto out; + + err = cfrfml_transmit_segment(rfml, frontpkt); + + frontpkt = NULL; +out: + + if (err != 0) { + pr_info("Connection error %d triggered on RFM link\n", err); + /* Trigger connection error upon failure.*/ + + layr->up->ctrlcmd(layr->up, CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND, + rfml->serv.dev_info.id); + + if (rearpkt) + cfpkt_destroy(rearpkt); + + if (frontpkt) + cfpkt_destroy(frontpkt); + } + + return err; +} |