File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/net/caif/cffrml.c b/net/caif/cffrml.c
new file mode 100644
index 0000000..434ba85
--- /dev/null
+++ b/net/caif/cffrml.c
@@ -0,0 +1,197 @@
+/*
+ * 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;
+ int 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;
+}