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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 | /* * CAIF Framing Layer. * * 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 <linux/crc-ccitt.h> #include <linux/netdevice.h> #include <net/caif/caif_layer.h> #include <net/caif/cfpkt.h> #include <net/caif/cffrml.h> #define container_obj(layr) container_of(layr, struct cffrml, layer) struct cffrml { struct cflayer layer; bool dofcs; /* !< FCS active */ int __percpu *pcpu_refcnt; }; static int cffrml_receive(struct cflayer *layr, struct cfpkt *pkt); static int cffrml_transmit(struct cflayer *layr, struct cfpkt *pkt); static void cffrml_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl, int phyid); static u32 cffrml_rcv_error; static u32 cffrml_rcv_checsum_error; struct cflayer *cffrml_create(u16 phyid, bool use_fcs) { struct cffrml *this = kzalloc(sizeof(struct cffrml), GFP_ATOMIC); if (!this) return NULL; this->pcpu_refcnt = alloc_percpu(int); if (this->pcpu_refcnt == NULL) { kfree(this); return NULL; } caif_assert(offsetof(struct cffrml, layer) == 0); this->layer.receive = cffrml_receive; this->layer.transmit = cffrml_transmit; this->layer.ctrlcmd = cffrml_ctrlcmd; snprintf(this->layer.name, CAIF_LAYER_NAME_SZ, "frm%d", phyid); this->dofcs = use_fcs; this->layer.id = phyid; return (struct cflayer *) this; } void cffrml_free(struct cflayer *layer) { struct cffrml *this = container_obj(layer); free_percpu(this->pcpu_refcnt); kfree(layer); } void cffrml_set_uplayer(struct cflayer *this, struct cflayer *up) { this->up = up; } void cffrml_set_dnlayer(struct cflayer *this, struct cflayer *dn) { this->dn = dn; } static u16 cffrml_checksum(u16 chks, void *buf, u16 len) { /* FIXME: FCS should be moved to glue in order to use OS-Specific * solutions */ return crc_ccitt(chks, buf, len); } static int cffrml_receive(struct cflayer *layr, struct cfpkt *pkt) { u16 tmp; u16 len; u16 hdrchks; u16 pktchks; struct cffrml *this; this = container_obj(layr); cfpkt_extr_head(pkt, &tmp, 2); len = le16_to_cpu(tmp); /* Subtract for FCS on length if FCS is not used. */ if (!this->dofcs) len -= 2; if (cfpkt_setlen(pkt, len) < 0) { ++cffrml_rcv_error; pr_err("Framing length error (%d)\n", len); cfpkt_destroy(pkt); return -EPROTO; } /* * Don't do extract if FCS is false, rather do setlen - then we don't * get a cache-miss. */ if (this->dofcs) { cfpkt_extr_trail(pkt, &tmp, 2); hdrchks = le16_to_cpu(tmp); pktchks = cfpkt_iterate(pkt, cffrml_checksum, 0xffff); if (pktchks != hdrchks) { cfpkt_add_trail(pkt, &tmp, 2); ++cffrml_rcv_error; ++cffrml_rcv_checsum_error; pr_info("Frame checksum error (0x%x != 0x%x)\n", hdrchks, pktchks); return -EILSEQ; } } if (cfpkt_erroneous(pkt)) { ++cffrml_rcv_error; pr_err("Packet is erroneous!\n"); cfpkt_destroy(pkt); return -EPROTO; } if (layr->up == NULL) { pr_err("Layr up is missing!\n"); cfpkt_destroy(pkt); return -EINVAL; } return layr->up->receive(layr->up, pkt); } static int cffrml_transmit(struct cflayer *layr, struct cfpkt *pkt) { u16 chks; u16 len; __le16 data; struct cffrml *this = container_obj(layr); if (this->dofcs) { chks = cfpkt_iterate(pkt, cffrml_checksum, 0xffff); data = cpu_to_le16(chks); cfpkt_add_trail(pkt, &data, 2); } else { cfpkt_pad_trail(pkt, 2); } len = cfpkt_getlen(pkt); data = cpu_to_le16(len); cfpkt_add_head(pkt, &data, 2); cfpkt_info(pkt)->hdr_len += 2; if (cfpkt_erroneous(pkt)) { pr_err("Packet is erroneous!\n"); cfpkt_destroy(pkt); return -EPROTO; } if (layr->dn == NULL) { cfpkt_destroy(pkt); return -ENODEV; } return layr->dn->transmit(layr->dn, pkt); } static void cffrml_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl, int phyid) { if (layr->up && layr->up->ctrlcmd) layr->up->ctrlcmd(layr->up, ctrl, layr->id); } void cffrml_put(struct cflayer *layr) { struct cffrml *this = container_obj(layr); if (layr != NULL && this->pcpu_refcnt != NULL) this_cpu_dec(*this->pcpu_refcnt); } void cffrml_hold(struct cflayer *layr) { struct cffrml *this = container_obj(layr); if (layr != NULL && this->pcpu_refcnt != NULL) this_cpu_inc(*this->pcpu_refcnt); } int cffrml_refcnt_read(struct cflayer *layr) { int i, refcnt = 0; struct cffrml *this = container_obj(layr); for_each_possible_cpu(i) refcnt += *per_cpu_ptr(this->pcpu_refcnt, i); return refcnt; } |