diff --git a/Documentation/networking/can.txt b/Documentation/networking/can.txt index a06741898f29f99ed6a766f50647c34521968b35..820f55344edc0a035358fa643bbe79c48d4d887f 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 25d371cf98dda73ef5507ed841629a07ded85df8..3b83bafcd9474c5089e4f1f17a05944471066dcd 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 9273f6d5c4b7ab8be244810a42c47f160a96ad7a..ad1cc842170add4076f17ec08c211bc16b7b647b 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 0000000000000000000000000000000000000000..914aecfa09a926a5423a0b9d0387e72dd9931382 --- /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 + * + * 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 +#include +#include +#include +#include + +#include + +#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 "); +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 f03d7a481a809902ea03ada0bb4ff6c9f2ca5196..239e4dd92ca1af77cc29df6bcd1563d6e6b7cd06 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 "); +/* 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 ea2d94285936bcc1e0df8b42beb297d7979ec1bf..4f93c0be00535025bdafc6d42d289b59c2c1bcff 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 17334c09bd933459fb3fb8586cabe0dc5af82168..1a66cf6112ae7d255c3e6585914720d6a6620951 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 0ccc1cd28b951876b2999c009c2acc1d612e8cc4..78c6c52073ad62948a7d750951ed94d232957048 100644 --- a/include/linux/can/core.h +++ b/include/linux/can/core.h @@ -17,10 +17,10 @@ #include #include -#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 5d2efe7e3f1bfb97429cbb30e8d0b31395ced8ac..ee5a771fb20d207cff444ec6f6310416713a5443 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 781f3a3701be1ad77482efa1fbd9e870292dc784..a814062b07191819c80812b843a46bd80870344b 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 56d907a2c80478d4c2932a3856662b59af2fdc1f..167ce5b363d2731aa4e5b82600164fb9ef52b245 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 6efcd37b4bd067958161ca1bfdb8d6d179a85898..821022a7214f544090eb8504bce180484bf0d79e 100644 --- a/net/can/af_can.c +++ b/net/can/af_can.c @@ -41,6 +41,7 @@ */ #include +#include #include #include #include @@ -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 46cca3a91d198093b86ea4d5701ecd42ce9dbce7..3e9c89356a939db3901d6ee664873691ac2accb1 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) {