4 * Copyright (C) ST-Ericsson AB 2010
5 * Author: Sjur Brendeland/sjur.brandeland@stericsson.com
6 * License terms: GNU General Public License (GPL) version 2
9 #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
11 #include <linux/stddef.h>
12 #include <linux/spinlock.h>
13 #include <linux/slab.h>
14 #include <linux/crc-ccitt.h>
15 #include <linux/netdevice.h>
16 #include <net/caif/caif_layer.h>
17 #include <net/caif/cfpkt.h>
18 #include <net/caif/cffrml.h>
20 #define container_obj(layr) container_of(layr, struct cffrml, layer)
24 bool dofcs; /* !< FCS active */
25 int __percpu *pcpu_refcnt;
28 static int cffrml_receive(struct cflayer *layr, struct cfpkt *pkt);
29 static int cffrml_transmit(struct cflayer *layr, struct cfpkt *pkt);
30 static void cffrml_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
33 static u32 cffrml_rcv_error;
34 static u32 cffrml_rcv_checsum_error;
35 struct cflayer *cffrml_create(u16 phyid, bool use_fcs)
37 struct cffrml *this = kmalloc(sizeof(struct cffrml), GFP_ATOMIC);
39 pr_warn("Out of memory\n");
42 this->pcpu_refcnt = alloc_percpu(int);
43 if (this->pcpu_refcnt == NULL) {
48 caif_assert(offsetof(struct cffrml, layer) == 0);
50 memset(this, 0, sizeof(struct cflayer));
51 this->layer.receive = cffrml_receive;
52 this->layer.transmit = cffrml_transmit;
53 this->layer.ctrlcmd = cffrml_ctrlcmd;
54 snprintf(this->layer.name, CAIF_LAYER_NAME_SZ, "frm%d", phyid);
55 this->dofcs = use_fcs;
56 this->layer.id = phyid;
57 return (struct cflayer *) this;
60 void cffrml_free(struct cflayer *layer)
62 struct cffrml *this = container_obj(layer);
63 free_percpu(this->pcpu_refcnt);
67 void cffrml_set_uplayer(struct cflayer *this, struct cflayer *up)
72 void cffrml_set_dnlayer(struct cflayer *this, struct cflayer *dn)
77 static u16 cffrml_checksum(u16 chks, void *buf, u16 len)
79 /* FIXME: FCS should be moved to glue in order to use OS-Specific
82 return crc_ccitt(chks, buf, len);
85 static int cffrml_receive(struct cflayer *layr, struct cfpkt *pkt)
92 this = container_obj(layr);
94 cfpkt_extr_head(pkt, &tmp, 2);
95 len = le16_to_cpu(tmp);
97 /* Subtract for FCS on length if FCS is not used. */
101 if (cfpkt_setlen(pkt, len) < 0) {
103 pr_err("Framing length error (%d)\n", len);
108 * Don't do extract if FCS is false, rather do setlen - then we don't
112 cfpkt_extr_trail(pkt, &tmp, 2);
113 hdrchks = le16_to_cpu(tmp);
114 pktchks = cfpkt_iterate(pkt, cffrml_checksum, 0xffff);
115 if (pktchks != hdrchks) {
116 cfpkt_add_trail(pkt, &tmp, 2);
118 ++cffrml_rcv_checsum_error;
119 pr_info("Frame checksum error (0x%x != 0x%x)\n",
124 if (cfpkt_erroneous(pkt)) {
126 pr_err("Packet is erroneous!\n");
131 if (layr->up == NULL) {
132 pr_err("Layr up is missing!\n");
137 return layr->up->receive(layr->up, pkt);
140 static int cffrml_transmit(struct cflayer *layr, struct cfpkt *pkt)
145 struct cffrml *this = container_obj(layr);
147 chks = cfpkt_iterate(pkt, cffrml_checksum, 0xffff);
148 tmp = cpu_to_le16(chks);
149 cfpkt_add_trail(pkt, &tmp, 2);
151 cfpkt_pad_trail(pkt, 2);
153 len = cfpkt_getlen(pkt);
154 tmp = cpu_to_le16(len);
155 cfpkt_add_head(pkt, &tmp, 2);
156 cfpkt_info(pkt)->hdr_len += 2;
157 if (cfpkt_erroneous(pkt)) {
158 pr_err("Packet is erroneous!\n");
163 if (layr->dn == NULL) {
168 return layr->dn->transmit(layr->dn, pkt);
171 static void cffrml_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
174 if (layr->up && layr->up->ctrlcmd)
175 layr->up->ctrlcmd(layr->up, ctrl, layr->id);
178 void cffrml_put(struct cflayer *layr)
180 struct cffrml *this = container_obj(layr);
181 if (layr != NULL && this->pcpu_refcnt != NULL)
182 irqsafe_cpu_dec(*this->pcpu_refcnt);
185 void cffrml_hold(struct cflayer *layr)
187 struct cffrml *this = container_obj(layr);
188 if (layr != NULL && this->pcpu_refcnt != NULL)
189 irqsafe_cpu_inc(*this->pcpu_refcnt);
192 int cffrml_refcnt_read(struct cflayer *layr)
195 struct cffrml *this = container_obj(layr);
196 for_each_possible_cpu(i)
197 refcnt += *per_cpu_ptr(this->pcpu_refcnt, i);