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-rw-r--r--Documentation/networking/can.txt154
-rw-r--r--drivers/net/can/c_can/Kconfig7
-rw-r--r--drivers/net/can/c_can/Makefile1
-rw-r--r--drivers/net/can/c_can/c_can_pci.c236
-rw-r--r--drivers/net/can/dev.c35
-rw-r--r--drivers/net/can/vcan.c27
-rw-r--r--include/linux/can.h59
-rw-r--r--include/linux/can/core.h4
-rw-r--r--include/linux/can/dev.h33
-rw-r--r--include/linux/can/raw.h3
-rw-r--r--include/linux/if_ether.h3
-rw-r--r--net/can/af_can.c116
-rw-r--r--net/can/raw.c50
13 files changed, 664 insertions, 64 deletions
diff --git a/Documentation/networking/can.txt b/Documentation/networking/can.txt
index a067418..820f553 100644
--- a/Documentation/networking/can.txt
+++ b/Documentation/networking/can.txt
@@ -22,7 +22,8 @@ This file contains
4.1.2 RAW socket option CAN_RAW_ERR_FILTER
4.1.3 RAW socket option CAN_RAW_LOOPBACK
4.1.4 RAW socket option CAN_RAW_RECV_OWN_MSGS
- 4.1.5 RAW socket returned message flags
+ 4.1.5 RAW socket option CAN_RAW_FD_FRAMES
+ 4.1.6 RAW socket returned message flags
4.2 Broadcast Manager protocol sockets (SOCK_DGRAM)
4.3 connected transport protocols (SOCK_SEQPACKET)
4.4 unconnected transport protocols (SOCK_DGRAM)
@@ -41,7 +42,8 @@ This file contains
6.5.1 Netlink interface to set/get devices properties
6.5.2 Setting the CAN bit-timing
6.5.3 Starting and stopping the CAN network device
- 6.6 supported CAN hardware
+ 6.6 CAN FD (flexible data rate) driver support
+ 6.7 supported CAN hardware
7 Socket CAN resources
@@ -273,7 +275,7 @@ solution for a couple of reasons:
struct can_frame {
canid_t can_id; /* 32 bit CAN_ID + EFF/RTR/ERR flags */
- __u8 can_dlc; /* data length code: 0 .. 8 */
+ __u8 can_dlc; /* frame payload length in byte (0 .. 8) */
__u8 data[8] __attribute__((aligned(8)));
};
@@ -375,6 +377,51 @@ solution for a couple of reasons:
nbytes = sendto(s, &frame, sizeof(struct can_frame),
0, (struct sockaddr*)&addr, sizeof(addr));
+ Remark about CAN FD (flexible data rate) support:
+
+ Generally the handling of CAN FD is very similar to the formerly described
+ examples. The new CAN FD capable CAN controllers support two different
+ bitrates for the arbitration phase and the payload phase of the CAN FD frame
+ and up to 64 bytes of payload. This extended payload length breaks all the
+ kernel interfaces (ABI) which heavily rely on the CAN frame with fixed eight
+ bytes of payload (struct can_frame) like the CAN_RAW socket. Therefore e.g.
+ the CAN_RAW socket supports a new socket option CAN_RAW_FD_FRAMES that
+ switches the socket into a mode that allows the handling of CAN FD frames
+ and (legacy) CAN frames simultaneously (see section 4.1.5).
+
+ The struct canfd_frame is defined in include/linux/can.h:
+
+ struct canfd_frame {
+ canid_t can_id; /* 32 bit CAN_ID + EFF/RTR/ERR flags */
+ __u8 len; /* frame payload length in byte (0 .. 64) */
+ __u8 flags; /* additional flags for CAN FD */
+ __u8 __res0; /* reserved / padding */
+ __u8 __res1; /* reserved / padding */
+ __u8 data[64] __attribute__((aligned(8)));
+ };
+
+ The struct canfd_frame and the existing struct can_frame have the can_id,
+ the payload length and the payload data at the same offset inside their
+ structures. This allows to handle the different structures very similar.
+ When the content of a struct can_frame is copied into a struct canfd_frame
+ all structure elements can be used as-is - only the data[] becomes extended.
+
+ When introducing the struct canfd_frame it turned out that the data length
+ code (DLC) of the struct can_frame was used as a length information as the
+ length and the DLC has a 1:1 mapping in the range of 0 .. 8. To preserve
+ the easy handling of the length information the canfd_frame.len element
+ contains a plain length value from 0 .. 64. So both canfd_frame.len and
+ can_frame.can_dlc are equal and contain a length information and no DLC.
+ For details about the distinction of CAN and CAN FD capable devices and
+ the mapping to the bus-relevant data length code (DLC), see chapter 6.6.
+
+ The length of the two CAN(FD) frame structures define the maximum transfer
+ unit (MTU) of the CAN(FD) network interface and skbuff data length. Two
+ definitions are specified for CAN specific MTUs in include/linux/can.h :
+
+ #define CAN_MTU (sizeof(struct can_frame)) == 16 => 'legacy' CAN frame
+ #define CANFD_MTU (sizeof(struct canfd_frame)) == 72 => CAN FD frame
+
4.1 RAW protocol sockets with can_filters (SOCK_RAW)
Using CAN_RAW sockets is extensively comparable to the commonly
@@ -472,7 +519,69 @@ solution for a couple of reasons:
setsockopt(s, SOL_CAN_RAW, CAN_RAW_RECV_OWN_MSGS,
&recv_own_msgs, sizeof(recv_own_msgs));
- 4.1.5 RAW socket returned message flags
+ 4.1.5 RAW socket option CAN_RAW_FD_FRAMES
+
+ CAN FD support in CAN_RAW sockets can be enabled with a new socket option
+ CAN_RAW_FD_FRAMES which is off by default. When the new socket option is
+ not supported by the CAN_RAW socket (e.g. on older kernels), switching the
+ CAN_RAW_FD_FRAMES option returns the error -ENOPROTOOPT.
+
+ Once CAN_RAW_FD_FRAMES is enabled the application can send both CAN frames
+ and CAN FD frames. OTOH the application has to handle CAN and CAN FD frames
+ when reading from the socket.
+
+ CAN_RAW_FD_FRAMES enabled: CAN_MTU and CANFD_MTU are allowed
+ CAN_RAW_FD_FRAMES disabled: only CAN_MTU is allowed (default)
+
+ Example:
+ [ remember: CANFD_MTU == sizeof(struct canfd_frame) ]
+
+ struct canfd_frame cfd;
+
+ nbytes = read(s, &cfd, CANFD_MTU);
+
+ if (nbytes == CANFD_MTU) {
+ printf("got CAN FD frame with length %d\n", cfd.len);
+ /* cfd.flags contains valid data */
+ } else if (nbytes == CAN_MTU) {
+ printf("got legacy CAN frame with length %d\n", cfd.len);
+ /* cfd.flags is undefined */
+ } else {
+ fprintf(stderr, "read: invalid CAN(FD) frame\n");
+ return 1;
+ }
+
+ /* the content can be handled independently from the received MTU size */
+
+ printf("can_id: %X data length: %d data: ", cfd.can_id, cfd.len);
+ for (i = 0; i < cfd.len; i++)
+ printf("%02X ", cfd.data[i]);
+
+ When reading with size CANFD_MTU only returns CAN_MTU bytes that have
+ been received from the socket a legacy CAN frame has been read into the
+ provided CAN FD structure. Note that the canfd_frame.flags data field is
+ not specified in the struct can_frame and therefore it is only valid in
+ CANFD_MTU sized CAN FD frames.
+
+ As long as the payload length is <=8 the received CAN frames from CAN FD
+ capable CAN devices can be received and read by legacy sockets too. When
+ user-generated CAN FD frames have a payload length <=8 these can be send
+ by legacy CAN network interfaces too. Sending CAN FD frames with payload
+ length > 8 to a legacy CAN network interface returns an -EMSGSIZE error.
+
+ Implementation hint for new CAN applications:
+
+ To build a CAN FD aware application use struct canfd_frame as basic CAN
+ data structure for CAN_RAW based applications. When the application is
+ executed on an older Linux kernel and switching the CAN_RAW_FD_FRAMES
+ socket option returns an error: No problem. You'll get legacy CAN frames
+ or CAN FD frames and can process them the same way.
+
+ When sending to CAN devices make sure that the device is capable to handle
+ CAN FD frames by checking if the device maximum transfer unit is CANFD_MTU.
+ The CAN device MTU can be retrieved e.g. with a SIOCGIFMTU ioctl() syscall.
+
+ 4.1.6 RAW socket returned message flags
When using recvmsg() call, the msg->msg_flags may contain following flags:
@@ -573,10 +682,13 @@ solution for a couple of reasons:
dev->type = ARPHRD_CAN; /* the netdevice hardware type */
dev->flags = IFF_NOARP; /* CAN has no arp */
- dev->mtu = sizeof(struct can_frame);
+ dev->mtu = CAN_MTU; /* sizeof(struct can_frame) -> legacy CAN interface */
- The struct can_frame is the payload of each socket buffer in the
- protocol family PF_CAN.
+ or alternative, when the controller supports CAN with flexible data rate:
+ dev->mtu = CANFD_MTU; /* sizeof(struct canfd_frame) -> CAN FD interface */
+
+ The struct can_frame or struct canfd_frame is the payload of each socket
+ buffer (skbuff) in the protocol family PF_CAN.
6.2 local loopback of sent frames
@@ -792,7 +904,33 @@ solution for a couple of reasons:
Note that a restart will also create a CAN error message frame (see
also chapter 3.4).
- 6.6 Supported CAN hardware
+ 6.6 CAN FD (flexible data rate) driver support
+
+ CAN FD capable CAN controllers support two different bitrates for the
+ arbitration phase and the payload phase of the CAN FD frame. Therefore a
+ second bittiming has to be specified in order to enable the CAN FD bitrate.
+
+ Additionally CAN FD capable CAN controllers support up to 64 bytes of
+ payload. The representation of this length in can_frame.can_dlc and
+ canfd_frame.len for userspace applications and inside the Linux network
+ layer is a plain value from 0 .. 64 instead of the CAN 'data length code'.
+ The data length code was a 1:1 mapping to the payload length in the legacy
+ CAN frames anyway. The payload length to the bus-relevant DLC mapping is
+ only performed inside the CAN drivers, preferably with the helper
+ functions can_dlc2len() and can_len2dlc().
+
+ The CAN netdevice driver capabilities can be distinguished by the network
+ devices maximum transfer unit (MTU):
+
+ MTU = 16 (CAN_MTU) => sizeof(struct can_frame) => 'legacy' CAN device
+ MTU = 72 (CANFD_MTU) => sizeof(struct canfd_frame) => CAN FD capable device
+
+ The CAN device MTU can be retrieved e.g. with a SIOCGIFMTU ioctl() syscall.
+ N.B. CAN FD capable devices can also handle and send legacy CAN frames.
+
+ FIXME: Add details about the CAN FD controller configuration when available.
+
+ 6.7 Supported CAN hardware
Please check the "Kconfig" file in "drivers/net/can" to get an actual
list of the support CAN hardware. On the Socket CAN project website
diff --git a/drivers/net/can/c_can/Kconfig b/drivers/net/can/c_can/Kconfig
index 25d371c..3b83baf 100644
--- a/drivers/net/can/c_can/Kconfig
+++ b/drivers/net/can/c_can/Kconfig
@@ -13,4 +13,11 @@ config CAN_C_CAN_PLATFORM
boards from ST Microelectronics (http://www.st.com) like the
SPEAr1310 and SPEAr320 evaluation boards & TI (www.ti.com)
boards like am335x, dm814x, dm813x and dm811x.
+
+config CAN_C_CAN_PCI
+ tristate "Generic PCI Bus based C_CAN/D_CAN driver"
+ depends on PCI
+ ---help---
+ This driver adds support for the C_CAN/D_CAN chips connected
+ to the PCI bus.
endif
diff --git a/drivers/net/can/c_can/Makefile b/drivers/net/can/c_can/Makefile
index 9273f6d..ad1cc84 100644
--- a/drivers/net/can/c_can/Makefile
+++ b/drivers/net/can/c_can/Makefile
@@ -4,5 +4,6 @@
obj-$(CONFIG_CAN_C_CAN) += c_can.o
obj-$(CONFIG_CAN_C_CAN_PLATFORM) += c_can_platform.o
+obj-$(CONFIG_CAN_C_CAN_PCI) += c_can_pci.o
ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
diff --git a/drivers/net/can/c_can/c_can_pci.c b/drivers/net/can/c_can/c_can_pci.c
new file mode 100644
index 0000000..914aecf
--- /dev/null
+++ b/drivers/net/can/c_can/c_can_pci.c
@@ -0,0 +1,236 @@
+/*
+ * PCI bus driver for Bosch C_CAN/D_CAN controller
+ *
+ * Copyright (C) 2012 Federico Vaga <federico.vaga@gmail.com>
+ *
+ * Borrowed from c_can_platform.c
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/clk.h>
+#include <linux/pci.h>
+
+#include <linux/can/dev.h>
+
+#include "c_can.h"
+
+enum c_can_pci_reg_align {
+ C_CAN_REG_ALIGN_16,
+ C_CAN_REG_ALIGN_32,
+};
+
+struct c_can_pci_data {
+ /* Specify if is C_CAN or D_CAN */
+ enum c_can_dev_id type;
+ /* Set the register alignment in the memory */
+ enum c_can_pci_reg_align reg_align;
+ /* Set the frequency if clk is not usable */
+ unsigned int freq;
+};
+
+/*
+ * 16-bit c_can registers can be arranged differently in the memory
+ * architecture of different implementations. For example: 16-bit
+ * registers can be aligned to a 16-bit boundary or 32-bit boundary etc.
+ * Handle the same by providing a common read/write interface.
+ */
+static u16 c_can_pci_read_reg_aligned_to_16bit(struct c_can_priv *priv,
+ enum reg index)
+{
+ return readw(priv->base + priv->regs[index]);
+}
+
+static void c_can_pci_write_reg_aligned_to_16bit(struct c_can_priv *priv,
+ enum reg index, u16 val)
+{
+ writew(val, priv->base + priv->regs[index]);
+}
+
+static u16 c_can_pci_read_reg_aligned_to_32bit(struct c_can_priv *priv,
+ enum reg index)
+{
+ return readw(priv->base + 2 * priv->regs[index]);
+}
+
+static void c_can_pci_write_reg_aligned_to_32bit(struct c_can_priv *priv,
+ enum reg index, u16 val)
+{
+ writew(val, priv->base + 2 * priv->regs[index]);
+}
+
+static int __devinit c_can_pci_probe(struct pci_dev *pdev,
+ const struct pci_device_id *ent)
+{
+ struct c_can_pci_data *c_can_pci_data = (void *)ent->driver_data;
+ struct c_can_priv *priv;
+ struct net_device *dev;
+ void __iomem *addr;
+ struct clk *clk;
+ int ret;
+
+ ret = pci_enable_device(pdev);
+ if (ret) {
+ dev_err(&pdev->dev, "pci_enable_device FAILED\n");
+ goto out;
+ }
+
+ ret = pci_request_regions(pdev, KBUILD_MODNAME);
+ if (ret) {
+ dev_err(&pdev->dev, "pci_request_regions FAILED\n");
+ goto out_disable_device;
+ }
+
+ pci_set_master(pdev);
+ pci_enable_msi(pdev);
+
+ addr = pci_iomap(pdev, 0, pci_resource_len(pdev, 0));
+ if (!addr) {
+ dev_err(&pdev->dev,
+ "device has no PCI memory resources, "
+ "failing adapter\n");
+ ret = -ENOMEM;
+ goto out_release_regions;
+ }
+
+ /* allocate the c_can device */
+ dev = alloc_c_can_dev();
+ if (!dev) {
+ ret = -ENOMEM;
+ goto out_iounmap;
+ }
+
+ priv = netdev_priv(dev);
+ pci_set_drvdata(pdev, dev);
+ SET_NETDEV_DEV(dev, &pdev->dev);
+
+ dev->irq = pdev->irq;
+ priv->base = addr;
+
+ if (!c_can_pci_data->freq) {
+ /* get the appropriate clk */
+ clk = clk_get(&pdev->dev, NULL);
+ if (IS_ERR(clk)) {
+ dev_err(&pdev->dev, "no clock defined\n");
+ ret = -ENODEV;
+ goto out_free_c_can;
+ }
+ priv->can.clock.freq = clk_get_rate(clk);
+ priv->priv = clk;
+ } else {
+ priv->can.clock.freq = c_can_pci_data->freq;
+ priv->priv = NULL;
+ }
+
+ /* Configure CAN type */
+ switch (c_can_pci_data->type) {
+ case C_CAN_DEVTYPE:
+ priv->regs = reg_map_c_can;
+ break;
+ case D_CAN_DEVTYPE:
+ priv->regs = reg_map_d_can;
+ priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
+ break;
+ default:
+ ret = -EINVAL;
+ goto out_free_clock;
+ }
+
+ /* Configure access to registers */
+ switch (c_can_pci_data->reg_align) {
+ case C_CAN_REG_ALIGN_32:
+ priv->read_reg = c_can_pci_read_reg_aligned_to_32bit;
+ priv->write_reg = c_can_pci_write_reg_aligned_to_32bit;
+ break;
+ case C_CAN_REG_ALIGN_16:
+ priv->read_reg = c_can_pci_read_reg_aligned_to_16bit;
+ priv->write_reg = c_can_pci_write_reg_aligned_to_16bit;
+ break;
+ default:
+ ret = -EINVAL;
+ goto out_free_clock;
+ }
+
+ ret = register_c_can_dev(dev);
+ if (ret) {
+ dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
+ KBUILD_MODNAME, ret);
+ goto out_free_clock;
+ }
+
+ dev_dbg(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
+ KBUILD_MODNAME, priv->regs, dev->irq);
+
+ return 0;
+
+out_free_clock:
+ if (priv->priv)
+ clk_put(priv->priv);
+out_free_c_can:
+ pci_set_drvdata(pdev, NULL);
+ free_c_can_dev(dev);
+out_iounmap:
+ pci_iounmap(pdev, addr);
+out_release_regions:
+ pci_disable_msi(pdev);
+ pci_clear_master(pdev);
+ pci_release_regions(pdev);
+out_disable_device:
+ pci_disable_device(pdev);
+out:
+ return ret;
+}
+
+static void __devexit c_can_pci_remove(struct pci_dev *pdev)
+{
+ struct net_device *dev = pci_get_drvdata(pdev);
+ struct c_can_priv *priv = netdev_priv(dev);
+
+ unregister_c_can_dev(dev);
+
+ if (priv->priv)
+ clk_put(priv->priv);
+
+ pci_set_drvdata(pdev, NULL);
+ free_c_can_dev(dev);
+
+ pci_iounmap(pdev, priv->base);
+ pci_disable_msi(pdev);
+ pci_clear_master(pdev);
+ pci_release_regions(pdev);
+ pci_disable_device(pdev);
+}
+
+static struct c_can_pci_data c_can_sta2x11= {
+ .type = C_CAN_DEVTYPE,
+ .reg_align = C_CAN_REG_ALIGN_32,
+ .freq = 52000000, /* 52 Mhz */
+};
+
+#define C_CAN_ID(_vend, _dev, _driverdata) { \
+ PCI_DEVICE(_vend, _dev), \
+ .driver_data = (unsigned long)&_driverdata, \
+}
+static DEFINE_PCI_DEVICE_TABLE(c_can_pci_tbl) = {
+ C_CAN_ID(PCI_VENDOR_ID_STMICRO, PCI_DEVICE_ID_STMICRO_CAN,
+ c_can_sta2x11),
+ {},
+};
+static struct pci_driver c_can_pci_driver = {
+ .name = KBUILD_MODNAME,
+ .id_table = c_can_pci_tbl,
+ .probe = c_can_pci_probe,
+ .remove = __devexit_p(c_can_pci_remove),
+};
+
+module_pci_driver(c_can_pci_driver);
+
+MODULE_AUTHOR("Federico Vaga <federico.vaga@gmail.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("PCI CAN bus driver for Bosch C_CAN/D_CAN controller");
+MODULE_DEVICE_TABLE(pci, c_can_pci_tbl);
diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
index f03d7a48..239e4dd 100644
--- a/drivers/net/can/dev.c
+++ b/drivers/net/can/dev.c
@@ -33,6 +33,39 @@ MODULE_DESCRIPTION(MOD_DESC);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
+/* CAN DLC to real data length conversion helpers */
+
+static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7,
+ 8, 12, 16, 20, 24, 32, 48, 64};
+
+/* get data length from can_dlc with sanitized can_dlc */
+u8 can_dlc2len(u8 can_dlc)
+{
+ return dlc2len[can_dlc & 0x0F];
+}
+EXPORT_SYMBOL_GPL(can_dlc2len);
+
+static const u8 len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, /* 0 - 8 */
+ 9, 9, 9, 9, /* 9 - 12 */
+ 10, 10, 10, 10, /* 13 - 16 */
+ 11, 11, 11, 11, /* 17 - 20 */
+ 12, 12, 12, 12, /* 21 - 24 */
+ 13, 13, 13, 13, 13, 13, 13, 13, /* 25 - 32 */
+ 14, 14, 14, 14, 14, 14, 14, 14, /* 33 - 40 */
+ 14, 14, 14, 14, 14, 14, 14, 14, /* 41 - 48 */
+ 15, 15, 15, 15, 15, 15, 15, 15, /* 49 - 56 */
+ 15, 15, 15, 15, 15, 15, 15, 15}; /* 57 - 64 */
+
+/* map the sanitized data length to an appropriate data length code */
+u8 can_len2dlc(u8 len)
+{
+ if (unlikely(len > 64))
+ return 0xF;
+
+ return len2dlc[len];
+}
+EXPORT_SYMBOL_GPL(can_len2dlc);
+
#ifdef CONFIG_CAN_CALC_BITTIMING
#define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */
@@ -454,7 +487,7 @@ EXPORT_SYMBOL_GPL(can_bus_off);
static void can_setup(struct net_device *dev)
{
dev->type = ARPHRD_CAN;
- dev->mtu = sizeof(struct can_frame);
+ dev->mtu = CAN_MTU;
dev->hard_header_len = 0;
dev->addr_len = 0;
dev->tx_queue_len = 10;
diff --git a/drivers/net/can/vcan.c b/drivers/net/can/vcan.c
index ea2d942..4f93c0b 100644
--- a/drivers/net/can/vcan.c
+++ b/drivers/net/can/vcan.c
@@ -70,13 +70,12 @@ MODULE_PARM_DESC(echo, "Echo sent frames (for testing). Default: 0 (Off)");
static void vcan_rx(struct sk_buff *skb, struct net_device *dev)
{
- struct can_frame *cf = (struct can_frame *)skb->data;
+ struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
struct net_device_stats *stats = &dev->stats;
stats->rx_packets++;
- stats->rx_bytes += cf->can_dlc;
+ stats->rx_bytes += cfd->len;
- skb->protocol = htons(ETH_P_CAN);
skb->pkt_type = PACKET_BROADCAST;
skb->dev = dev;
skb->ip_summed = CHECKSUM_UNNECESSARY;
@@ -86,7 +85,7 @@ static void vcan_rx(struct sk_buff *skb, struct net_device *dev)
static netdev_tx_t vcan_tx(struct sk_buff *skb, struct net_device *dev)
{
- struct can_frame *cf = (struct can_frame *)skb->data;
+ struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
struct net_device_stats *stats = &dev->stats;
int loop;
@@ -94,7 +93,7 @@ static netdev_tx_t vcan_tx(struct sk_buff *skb, struct net_device *dev)
return NETDEV_TX_OK;
stats->tx_packets++;
- stats->tx_bytes += cf->can_dlc;
+ stats->tx_bytes += cfd->len;
/* set flag whether this packet has to be looped back */
loop = skb->pkt_type == PACKET_LOOPBACK;
@@ -108,7 +107,7 @@ static netdev_tx_t vcan_tx(struct sk_buff *skb, struct net_device *dev)
* CAN core already did the echo for us
*/
stats->rx_packets++;
- stats->rx_bytes += cf->can_dlc;
+ stats->rx_bytes += cfd->len;
}
kfree_skb(skb);
return NETDEV_TX_OK;
@@ -133,14 +132,28 @@ static netdev_tx_t vcan_tx(struct sk_buff *skb, struct net_device *dev)
return NETDEV_TX_OK;
}
+static int vcan_change_mtu(struct net_device *dev, int new_mtu)
+{
+ /* Do not allow changing the MTU while running */
+ if (dev->flags & IFF_UP)
+ return -EBUSY;
+
+ if (new_mtu != CAN_MTU && new_mtu != CANFD_MTU)
+ return -EINVAL;
+
+ dev->mtu = new_mtu;
+ return 0;
+}
+
static const struct net_device_ops vcan_netdev_ops = {
.ndo_start_xmit = vcan_tx,
+ .ndo_change_mtu = vcan_change_mtu,
};
static void vcan_setup(struct net_device *dev)
{
dev->type = ARPHRD_CAN;
- dev->mtu = sizeof(struct can_frame);
+ dev->mtu = CAN_MTU;
dev->hard_header_len = 0;
dev->addr_len = 0;
dev->tx_queue_len = 0;
diff --git a/include/linux/can.h b/include/linux/can.h
index 17334c0..1a66cf61 100644
--- a/include/linux/can.h
+++ b/include/linux/can.h
@@ -46,18 +46,67 @@ typedef __u32 canid_t;
*/
typedef __u32 can_err_mask_t;
+/* CAN payload length and DLC definitions according to ISO 11898-1 */
+#define CAN_MAX_DLC 8
+#define CAN_MAX_DLEN 8
+
+/* CAN FD payload length and DLC definitions according to ISO 11898-7 */
+#define CANFD_MAX_DLC 15
+#define CANFD_MAX_DLEN 64
+
/**
* struct can_frame - basic CAN frame structure
- * @can_id: the CAN ID of the frame and CAN_*_FLAG flags, see above.
- * @can_dlc: the data length field of the CAN frame
- * @data: the CAN frame payload.
+ * @can_id: CAN ID of the frame and CAN_*_FLAG flags, see canid_t definition
+ * @can_dlc: frame payload length in byte (0 .. 8) aka data length code
+ * N.B. the DLC field from ISO 11898-1 Chapter 8.4.2.3 has a 1:1
+ * mapping of the 'data length code' to the real payload length
+ * @data: CAN frame payload (up to 8 byte)
*/
struct can_frame {
canid_t can_id; /* 32 bit CAN_ID + EFF/RTR/ERR flags */
- __u8 can_dlc; /* data length code: 0 .. 8 */
- __u8 data[8] __attribute__((aligned(8)));
+ __u8 can_dlc; /* frame payload length in byte (0 .. CAN_MAX_DLEN) */
+ __u8 data[CAN_MAX_DLEN] __attribute__((aligned(8)));
};
+/*
+ * defined bits for canfd_frame.flags
+ *
+ * As the default for CAN FD should be to support the high data rate in the
+ * payload section of the frame (HDR) and to support up to 64 byte in the
+ * data section (EDL) the bits are only set in the non-default case.
+ * Btw. as long as there's no real implementation for CAN FD network driver
+ * these bits are only preliminary.
+ *
+ * RX: NOHDR/NOEDL - info about received CAN FD frame
+ * ESI - bit from originating CAN controller
+ * TX: NOHDR/NOEDL - control per-frame settings if supported by CAN controller
+ * ESI - bit is set by local CAN controller
+ */
+#define CANFD_NOHDR 0x01 /* frame without high data rate */
+#define CANFD_NOEDL 0x02 /* frame without extended data length */
+#define CANFD_ESI 0x04 /* error state indicator */
+
+/**
+ * struct canfd_frame - CAN flexible data rate frame structure
+ * @can_id: CAN ID of the frame and CAN_*_FLAG flags, see canid_t definition
+ * @len: frame payload length in byte (0 .. CANFD_MAX_DLEN)
+ * @flags: additional flags for CAN FD
+ * @__res0: reserved / padding
+ * @__res1: reserved / padding
+ * @data: CAN FD frame payload (up to CANFD_MAX_DLEN byte)
+ */
+struct canfd_frame {
+ canid_t can_id; /* 32 bit CAN_ID + EFF/RTR/ERR flags */
+ __u8 len; /* frame payload length in byte */
+ __u8 flags; /* additional flags for CAN FD */
+ __u8 __res0; /* reserved / padding */
+ __u8 __res1; /* reserved / padding */
+ __u8 data[CANFD_MAX_DLEN] __attribute__((aligned(8)));
+};
+
+#define CAN_MTU (sizeof(struct can_frame))
+#define CANFD_MTU (sizeof(struct canfd_frame))
+
/* particular protocols of the protocol family PF_CAN */
#define CAN_RAW 1 /* RAW sockets */
#define CAN_BCM 2 /* Broadcast Manager */
diff --git a/include/linux/can/core.h b/include/linux/can/core.h
index 0ccc1cd..78c6c52 100644
--- a/include/linux/can/core.h
+++ b/include/linux/can/core.h
@@ -17,10 +17,10 @@
#include <linux/skbuff.h>
#include <linux/netdevice.h>
-#define CAN_VERSION "20090105"
+#define CAN_VERSION "20120528"
/* increment this number each time you change some user-space interface */
-#define CAN_ABI_VERSION "8"
+#define CAN_ABI_VERSION "9"
#define CAN_VERSION_STRING "rev " CAN_VERSION " abi " CAN_ABI_VERSION
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index 5d2efe7..ee5a771 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -61,23 +61,40 @@ struct can_priv {
* To be used in the CAN netdriver receive path to ensure conformance with
* ISO 11898-1 Chapter 8.4.2.3 (DLC field)
*/
-#define get_can_dlc(i) (min_t(__u8, (i), 8))
+#define get_can_dlc(i) (min_t(__u8, (i), CAN_MAX_DLC))
+#define get_canfd_dlc(i) (min_t(__u8, (i), CANFD_MAX_DLC))
/* Drop a given socketbuffer if it does not contain a valid CAN frame. */
static inline int can_dropped_invalid_skb(struct net_device *dev,
struct sk_buff *skb)
{
- const struct can_frame *cf = (struct can_frame *)skb->data;
-
- if (unlikely(skb->len != sizeof(*cf) || cf->can_dlc > 8)) {
- kfree_skb(skb);
- dev->stats.tx_dropped++;
- return 1;
- }
+ const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+
+ if (skb->protocol == htons(ETH_P_CAN)) {
+ if (unlikely(skb->len != CAN_MTU ||
+ cfd->len > CAN_MAX_DLEN))
+ goto inval_skb;
+ } else if (skb->protocol == htons(ETH_P_CANFD)) {
+ if (unlikely(skb->len != CANFD_MTU ||
+ cfd->len > CANFD_MAX_DLEN))
+ goto inval_skb;
+ } else
+ goto inval_skb;
return 0;
+
+inval_skb:
+ kfree_skb(skb);
+ dev->stats.tx_dropped++;
+ return 1;
}
+/* get data length from can_dlc with sanitized can_dlc */
+u8 can_dlc2len(u8 can_dlc);
+
+/* map the sanitized data length to an appropriate data length code */
+u8 can_len2dlc(u8 len);
+
struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max);
void free_candev(struct net_device *dev);
diff --git a/include/linux/can/raw.h b/include/linux/can/raw.h
index 781f3a3..a814062 100644
--- a/include/linux/can/raw.h
+++ b/include/linux/can/raw.h
@@ -23,7 +23,8 @@ enum {
CAN_RAW_FILTER = 1, /* set 0 .. n can_filter(s) */
CAN_RAW_ERR_FILTER, /* set filter for error frames */
CAN_RAW_LOOPBACK, /* local loopback (default:on) */
- CAN_RAW_RECV_OWN_MSGS /* receive my own msgs (default:off) */
+ CAN_RAW_RECV_OWN_MSGS, /* receive my own msgs (default:off) */
+ CAN_RAW_FD_FRAMES, /* allow CAN FD frames (default:off) */
};
#endif
diff --git a/include/linux/if_ether.h b/include/linux/if_ether.h
index 56d907a..167ce5b 100644
--- a/include/linux/if_ether.h
+++ b/include/linux/if_ether.h
@@ -105,7 +105,8 @@
#define ETH_P_WAN_PPP 0x0007 /* Dummy type for WAN PPP frames*/
#define ETH_P_PPP_MP 0x0008 /* Dummy type for PPP MP frames */
#define ETH_P_LOCALTALK 0x0009 /* Localtalk pseudo type */
-#define ETH_P_CAN 0x000C /* Controller Area Network */
+#define ETH_P_CAN 0x000C /* CAN: Controller Area Network */
+#define ETH_P_CANFD 0x000D /* CANFD: CAN flexible data rate*/
#define ETH_P_PPPTALK 0x0010 /* Dummy type for Atalk over PPP*/
#define ETH_P_TR_802_2 0x0011 /* 802.2 frames */
#define ETH_P_MOBITEX 0x0015 /* Mobitex (kaz@cafe.net) */
diff --git a/net/can/af_can.c b/net/can/af_can.c
index 6efcd37..821022a 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -41,6 +41,7 @@
*/
#include <linux/module.h>
+#include <linux/stddef.h>
#include <linux/init.h>
#include <linux/kmod.h>
#include <linux/slab.h>
@@ -220,30 +221,46 @@ static int can_create(struct net *net, struct socket *sock, int protocol,
* -ENOBUFS on full driver queue (see net_xmit_errno())
* -ENOMEM when local loopback failed at calling skb_clone()
* -EPERM when trying to send on a non-CAN interface
+ * -EMSGSIZE CAN frame size is bigger than CAN interface MTU
* -EINVAL when the skb->data does not contain a valid CAN frame
*/
int can_send(struct sk_buff *skb, int loop)
{
struct sk_buff *newskb = NULL;
- struct can_frame *cf = (struct can_frame *)skb->data;
- int err;
+ struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+ int err = -EINVAL;
+
+ if (skb->len == CAN_MTU) {
+ skb->protocol = htons(ETH_P_CAN);
+ if (unlikely(cfd->len > CAN_MAX_DLEN))
+ goto inval_skb;
+ } else if (skb->len == CANFD_MTU) {
+ skb->protocol = htons(ETH_P_CANFD);
+ if (unlikely(cfd->len > CANFD_MAX_DLEN))
+ goto inval_skb;
+ } else
+ goto inval_skb;
- if (skb->len != sizeof(struct can_frame) || cf->can_dlc > 8) {
- kfree_skb(skb);
- return -EINVAL;
+ /*
+ * Make sure the CAN frame can pass the selected CAN netdevice.
+ * As structs can_frame and canfd_frame are similar, we can provide
+ * CAN FD frames to legacy CAN drivers as long as the length is <= 8
+ */
+ if (unlikely(skb->len > skb->dev->mtu && cfd->len > CAN_MAX_DLEN)) {
+ err = -EMSGSIZE;
+ goto inval_skb;
}
- if (skb->dev->type != ARPHRD_CAN) {
- kfree_skb(skb);
- return -EPERM;
+ if (unlikely(skb->dev->type != ARPHRD_CAN)) {
+ err = -EPERM;
+ goto inval_skb;
}
- if (!(skb->dev->flags & IFF_UP)) {
- kfree_skb(skb);
- return -ENETDOWN;
+ if (unlikely(!(skb->dev->flags & IFF_UP))) {
+ err = -ENETDOWN;
+ goto inval_skb;
}
- skb->protocol = htons(ETH_P_CAN);
skb_reset_network_header(skb);
skb_reset_transport_header(skb);
@@ -300,6 +317,10 @@ int can_send(struct sk_buff *skb, int loop)
can_stats.tx_frames_delta++;
return 0;
+
+inval_skb:
+ kfree_skb(skb);
+ return err;
}
EXPORT_SYMBOL(can_send);
@@ -632,24 +653,11 @@ static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb)
return matches;
}
-static int can_rcv(struct sk_buff *skb, struct net_device *dev,
- struct packet_type *pt, struct net_device *orig_dev)
+static void can_receive(struct sk_buff *skb, struct net_device *dev)
{
struct dev_rcv_lists *d;
- struct can_frame *cf = (struct can_frame *)skb->data;
int matches;
- if (!net_eq(dev_net(dev), &init_net))
- goto drop;
-
- if (WARN_ONCE(dev->type != ARPHRD_CAN ||
- skb->len != sizeof(struct can_frame) ||
- cf->can_dlc > 8,
- "PF_CAN: dropped non conform skbuf: "
- "dev type %d, len %d, can_dlc %d\n",
- dev->type, skb->len, cf->can_dlc))
- goto drop;
-
/* update statistics */
can_stats.rx_frames++;
can_stats.rx_frames_delta++;
@@ -673,7 +681,49 @@ static int can_rcv(struct sk_buff *skb, struct net_device *dev,
can_stats.matches++;
can_stats.matches_delta++;
}
+}
+static int can_rcv(struct sk_buff *skb, struct net_device *dev,
+ struct packet_type *pt, struct net_device *orig_dev)
+{
+ struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+
+ if (unlikely(!net_eq(dev_net(dev), &init_net)))
+ goto drop;
+
+ if (WARN_ONCE(dev->type != ARPHRD_CAN ||
+ skb->len != CAN_MTU ||
+ cfd->len > CAN_MAX_DLEN,
+ "PF_CAN: dropped non conform CAN skbuf: "
+ "dev type %d, len %d, datalen %d\n",
+ dev->type, skb->len, cfd->len))
+ goto drop;
+
+ can_receive(skb, dev);
+ return NET_RX_SUCCESS;
+
+drop:
+ kfree_skb(skb);
+ return NET_RX_DROP;
+}
+
+static int canfd_rcv(struct sk_buff *skb, struct net_device *dev,
+ struct packet_type *pt, struct net_device *orig_dev)
+{
+ struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+
+ if (unlikely(!net_eq(dev_net(dev), &init_net)))
+ goto drop;
+
+ if (WARN_ONCE(dev->type != ARPHRD_CAN ||
+ skb->len != CANFD_MTU ||
+ cfd->len > CANFD_MAX_DLEN,
+ "PF_CAN: dropped non conform CAN FD skbuf: "
+ "dev type %d, len %d, datalen %d\n",
+ dev->type, skb->len, cfd->len))
+ goto drop;
+
+ can_receive(skb, dev);
return NET_RX_SUCCESS;
drop:
@@ -807,10 +857,14 @@ static int can_notifier(struct notifier_block *nb, unsigned long msg,
static struct packet_type can_packet __read_mostly = {
.type = cpu_to_be16(ETH_P_CAN),
- .dev = NULL,
.func = can_rcv,
};
+static struct packet_type canfd_packet __read_mostly = {
+ .type = cpu_to_be16(ETH_P_CANFD),
+ .func = canfd_rcv,
+};
+
static const struct net_proto_family can_family_ops = {
.family = PF_CAN,
.create = can_create,
@@ -824,6 +878,12 @@ static struct notifier_block can_netdev_notifier __read_mostly = {
static __init int can_init(void)
{
+ /* check for correct padding to be able to use the structs similarly */
+ BUILD_BUG_ON(offsetof(struct can_frame, can_dlc) !=
+ offsetof(struct canfd_frame, len) ||
+ offsetof(struct can_frame, data) !=
+ offsetof(struct canfd_frame, data));
+
printk(banner);
memset(&can_rx_alldev_list, 0, sizeof(can_rx_alldev_list));
@@ -846,6 +906,7 @@ static __init int can_init(void)
sock_register(&can_family_ops);
register_netdevice_notifier(&can_netdev_notifier);
dev_add_pack(&can_packet);
+ dev_add_pack(&canfd_packet);
return 0;
}
@@ -860,6 +921,7 @@ static __exit void can_exit(void)
can_remove_proc();
/* protocol unregister */
+ dev_remove_pack(&canfd_packet);
dev_remove_pack(&can_packet);
unregister_netdevice_notifier(&can_netdev_notifier);
sock_unregister(PF_CAN);
diff --git a/net/can/raw.c b/net/can/raw.c
index 46cca3a..3e9c893 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -82,6 +82,7 @@ struct raw_sock {
struct notifier_block notifier;
int loopback;
int recv_own_msgs;
+ int fd_frames;
int count; /* number of active filters */
struct can_filter dfilter; /* default/single filter */
struct can_filter *filter; /* pointer to filter(s) */
@@ -119,6 +120,14 @@ static void raw_rcv(struct sk_buff *oskb, void *data)
if (!ro->recv_own_msgs && oskb->sk == sk)
return;
+ /* do not pass frames with DLC > 8 to a legacy socket */
+ if (!ro->fd_frames) {
+ struct canfd_frame *cfd = (struct canfd_frame *)oskb->data;
+
+ if (unlikely(cfd->len > CAN_MAX_DLEN))
+ return;
+ }
+
/* clone the given skb to be able to enqueue it into the rcv queue */
skb = skb_clone(oskb, GFP_ATOMIC);
if (!skb)
@@ -291,6 +300,7 @@ static int raw_init(struct sock *sk)
/* set default loopback behaviour */
ro->loopback = 1;
ro->recv_own_msgs = 0;
+ ro->fd_frames = 0;
/* set notifier */
ro->notifier.notifier_call = raw_notifier;
@@ -569,6 +579,15 @@ static int raw_setsockopt(struct socket *sock, int level, int optname,
break;
+ case CAN_RAW_FD_FRAMES:
+ if (optlen != sizeof(ro->fd_frames))
+ return -EINVAL;
+
+ if (copy_from_user(&ro->fd_frames, optval, optlen))
+ return -EFAULT;
+
+ break;
+
default:
return -ENOPROTOOPT;
}
@@ -627,6 +646,12 @@ static int raw_getsockopt(struct socket *sock, int level, int optname,
val = &ro->recv_own_msgs;
break;
+ case CAN_RAW_FD_FRAMES:
+ if (len > sizeof(int))
+ len = sizeof(int);
+ val = &ro->fd_frames;
+ break;
+
default:
return -ENOPROTOOPT;
}
@@ -662,8 +687,13 @@ static int raw_sendmsg(struct kiocb *iocb, struct socket *sock,
} else
ifindex = ro->ifindex;
- if (size != sizeof(struct can_frame))
- return -EINVAL;
+ if (ro->fd_frames) {
+ if (unlikely(size != CANFD_MTU && size != CAN_MTU))
+ return -EINVAL;
+ } else {
+ if (unlikely(size != CAN_MTU))
+ return -EINVAL;
+ }
dev = dev_get_by_index(&init_net, ifindex);
if (!dev)
@@ -705,7 +735,9 @@ static int raw_recvmsg(struct kiocb *iocb, struct socket *sock,
struct msghdr *msg, size_t size, int flags)
{
struct sock *sk = sock->sk;
+ struct raw_sock *ro = raw_sk(sk);
struct sk_buff *skb;
+ int rxmtu;
int err = 0;
int noblock;
@@ -716,10 +748,20 @@ static int raw_recvmsg(struct kiocb *iocb, struct socket *sock,
if (!skb)
return err;
- if (size < skb->len)
+ /*
+ * when serving a legacy socket the DLC <= 8 is already checked inside
+ * raw_rcv(). Now check if we need to pass a canfd_frame to a legacy
+ * socket and cut the possible CANFD_MTU/CAN_MTU length to CAN_MTU
+ */
+ if (!ro->fd_frames)
+ rxmtu = CAN_MTU;
+ else
+ rxmtu = skb->len;
+
+ if (size < rxmtu)
msg->msg_flags |= MSG_TRUNC;
else
- size = skb->len;
+ size = rxmtu;
err = memcpy_toiovec(msg->msg_iov, skb->data, size);
if (err < 0) {
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