![Sjur Braendeland](/assets/img/avatar_default.png)
Previously CAIF supported maximum transfer size of ~4050. The transfer size is now calculated dynamically based on the link layers mtu size. Signed-off-by: Sjur Braendeland@stericsson.com Signed-off-by: David S. Miller <davem@davemloft.net>
114 lines
2.9 KiB
C
114 lines
2.9 KiB
C
/*
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* Copyright (C) ST-Ericsson AB 2010
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* Author: Sjur Brendeland/sjur.brandeland@stericsson.com
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* License terms: GNU General Public License (GPL) version 2
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*/
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#include <linux/stddef.h>
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#include <linux/spinlock.h>
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#include <linux/slab.h>
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#include <net/caif/caif_layer.h>
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#include <net/caif/cfsrvl.h>
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#include <net/caif/cfpkt.h>
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#define container_obj(layr) ((struct cfsrvl *) layr)
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#define DGM_CMD_BIT 0x80
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#define DGM_FLOW_OFF 0x81
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#define DGM_FLOW_ON 0x80
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#define DGM_CTRL_PKT_SIZE 1
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#define DGM_MTU 1500
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static int cfdgml_receive(struct cflayer *layr, struct cfpkt *pkt);
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static int cfdgml_transmit(struct cflayer *layr, struct cfpkt *pkt);
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struct cflayer *cfdgml_create(u8 channel_id, struct dev_info *dev_info)
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{
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struct cfsrvl *dgm = kmalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
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if (!dgm) {
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pr_warning("CAIF: %s(): Out of memory\n", __func__);
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return NULL;
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}
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caif_assert(offsetof(struct cfsrvl, layer) == 0);
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memset(dgm, 0, sizeof(struct cfsrvl));
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cfsrvl_init(dgm, channel_id, dev_info, true);
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dgm->layer.receive = cfdgml_receive;
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dgm->layer.transmit = cfdgml_transmit;
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snprintf(dgm->layer.name, CAIF_LAYER_NAME_SZ - 1, "dgm%d", channel_id);
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dgm->layer.name[CAIF_LAYER_NAME_SZ - 1] = '\0';
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return &dgm->layer;
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}
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static int cfdgml_receive(struct cflayer *layr, struct cfpkt *pkt)
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{
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u8 cmd = -1;
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u8 dgmhdr[3];
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int ret;
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caif_assert(layr->up != NULL);
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caif_assert(layr->receive != NULL);
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caif_assert(layr->ctrlcmd != NULL);
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if (cfpkt_extr_head(pkt, &cmd, 1) < 0) {
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pr_err("CAIF: %s(): Packet is erroneous!\n", __func__);
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cfpkt_destroy(pkt);
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return -EPROTO;
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}
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if ((cmd & DGM_CMD_BIT) == 0) {
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if (cfpkt_extr_head(pkt, &dgmhdr, 3) < 0) {
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pr_err("CAIF: %s(): Packet is erroneous!\n", __func__);
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cfpkt_destroy(pkt);
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return -EPROTO;
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}
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ret = layr->up->receive(layr->up, pkt);
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return ret;
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}
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switch (cmd) {
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case DGM_FLOW_OFF: /* FLOW OFF */
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layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0);
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cfpkt_destroy(pkt);
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return 0;
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case DGM_FLOW_ON: /* FLOW ON */
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layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0);
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cfpkt_destroy(pkt);
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return 0;
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default:
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cfpkt_destroy(pkt);
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pr_info("CAIF: %s(): Unknown datagram control %d (0x%x)\n",
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__func__, cmd, cmd);
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return -EPROTO;
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}
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}
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static int cfdgml_transmit(struct cflayer *layr, struct cfpkt *pkt)
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{
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u32 zero = 0;
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struct caif_payload_info *info;
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struct cfsrvl *service = container_obj(layr);
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int ret;
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if (!cfsrvl_ready(service, &ret))
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return ret;
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/* STE Modem cannot handle more than 1500 bytes datagrams */
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if (cfpkt_getlen(pkt) > DGM_MTU)
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return -EMSGSIZE;
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cfpkt_add_head(pkt, &zero, 4);
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/* Add info for MUX-layer to route the packet out. */
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info = cfpkt_info(pkt);
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info->channel_id = service->layer.id;
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/* To optimize alignment, we add up the size of CAIF header
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* before payload.
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*/
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info->hdr_len = 4;
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info->dev_info = &service->dev_info;
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ret = layr->dn->transmit(layr->dn, pkt);
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if (ret < 0) {
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u32 tmp32;
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cfpkt_extr_head(pkt, &tmp32, 4);
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}
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return ret;
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}
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