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-rw-r--r--drivers/net/mctp/Kconfig24
-rw-r--r--drivers/net/mctp/Makefile2
-rw-r--r--drivers/net/mctp/mctp-i2c.c61
-rw-r--r--drivers/net/mctp/mctp-i3c.c767
-rw-r--r--drivers/net/mctp/mctp-serial.c146
-rw-r--r--drivers/net/mctp/mctp-usb.c390
6 files changed, 1366 insertions, 24 deletions
diff --git a/drivers/net/mctp/Kconfig b/drivers/net/mctp/Kconfig
index dc71657d9184..cf325ab0b1ef 100644
--- a/drivers/net/mctp/Kconfig
+++ b/drivers/net/mctp/Kconfig
@@ -21,6 +21,11 @@ config MCTP_SERIAL
Say y here if you need to connect to MCTP endpoints over serial. To
compile as a module, use m; the module will be called mctp-serial.
+config MCTP_SERIAL_TEST
+ bool "MCTP serial tests" if !KUNIT_ALL_TESTS
+ depends on MCTP_SERIAL=y && KUNIT=y
+ default KUNIT_ALL_TESTS
+
config MCTP_TRANSPORT_I2C
tristate "MCTP SMBus/I2C transport"
# i2c-mux is optional, but we must build as a module if i2c-mux is a module
@@ -33,6 +38,25 @@ config MCTP_TRANSPORT_I2C
from DMTF specification DSP0237. A MCTP protocol network device is
created for each I2C bus that has been assigned a mctp-i2c device.
+config MCTP_TRANSPORT_I3C
+ tristate "MCTP I3C transport"
+ depends on I3C
+ help
+ Provides a driver to access MCTP devices over I3C transport,
+ from DMTF specification DSP0233.
+ A MCTP protocol network device is created for each I3C bus
+ having a "mctp-controller" devicetree property.
+
+config MCTP_TRANSPORT_USB
+ tristate "MCTP USB transport"
+ depends on USB
+ help
+ Provides a driver to access MCTP devices over USB transport,
+ defined by DMTF specification DSP0283.
+
+ MCTP-over-USB interfaces are peer-to-peer, so each interface
+ represents a physical connection to one remote MCTP endpoint.
+
endmenu
endif
diff --git a/drivers/net/mctp/Makefile b/drivers/net/mctp/Makefile
index 1ca3e6028f77..c36006849a1e 100644
--- a/drivers/net/mctp/Makefile
+++ b/drivers/net/mctp/Makefile
@@ -1,2 +1,4 @@
obj-$(CONFIG_MCTP_SERIAL) += mctp-serial.o
obj-$(CONFIG_MCTP_TRANSPORT_I2C) += mctp-i2c.o
+obj-$(CONFIG_MCTP_TRANSPORT_I3C) += mctp-i3c.o
+obj-$(CONFIG_MCTP_TRANSPORT_USB) += mctp-usb.o
diff --git a/drivers/net/mctp/mctp-i2c.c b/drivers/net/mctp/mctp-i2c.c
index 1d67a3ca1fd1..f782d93f826e 100644
--- a/drivers/net/mctp/mctp-i2c.c
+++ b/drivers/net/mctp/mctp-i2c.c
@@ -177,8 +177,7 @@ static struct mctp_i2c_client *mctp_i2c_new_client(struct i2c_client *client)
return mcli;
err:
if (mcli) {
- if (mcli->client)
- i2c_unregister_device(mcli->client);
+ i2c_unregister_device(mcli->client);
kfree(mcli);
}
return ERR_PTR(rc);
@@ -442,6 +441,42 @@ static void mctp_i2c_unlock_reset(struct mctp_i2c_dev *midev)
i2c_unlock_bus(midev->adapter, I2C_LOCK_SEGMENT);
}
+static void mctp_i2c_invalidate_tx_flow(struct mctp_i2c_dev *midev,
+ struct sk_buff *skb)
+{
+ struct mctp_sk_key *key;
+ struct mctp_flow *flow;
+ unsigned long flags;
+ bool release;
+
+ flow = skb_ext_find(skb, SKB_EXT_MCTP);
+ if (!flow)
+ return;
+
+ key = flow->key;
+ if (!key)
+ return;
+
+ spin_lock_irqsave(&key->lock, flags);
+ if (key->manual_alloc) {
+ /* we don't have control over lifetimes for manually-allocated
+ * keys, so cannot assume we can invalidate all future flows
+ * that would use this key.
+ */
+ release = false;
+ } else {
+ release = key->dev_flow_state == MCTP_I2C_FLOW_STATE_ACTIVE;
+ key->dev_flow_state = MCTP_I2C_FLOW_STATE_INVALID;
+ }
+ spin_unlock_irqrestore(&key->lock, flags);
+
+ /* if we have changed state from active, the flow held a reference on
+ * the lock; release that now.
+ */
+ if (release)
+ mctp_i2c_unlock_nest(midev);
+}
+
static void mctp_i2c_xmit(struct mctp_i2c_dev *midev, struct sk_buff *skb)
{
struct net_device_stats *stats = &midev->ndev->stats;
@@ -500,6 +535,11 @@ static void mctp_i2c_xmit(struct mctp_i2c_dev *midev, struct sk_buff *skb)
case MCTP_I2C_TX_FLOW_EXISTING:
/* existing flow: we already have the lock; just tx */
rc = __i2c_transfer(midev->adapter, &msg, 1);
+
+ /* on tx errors, the flow can no longer be considered valid */
+ if (rc < 0)
+ mctp_i2c_invalidate_tx_flow(midev, skb);
+
break;
case MCTP_I2C_TX_FLOW_INVALID:
@@ -543,13 +583,21 @@ static int mctp_i2c_header_create(struct sk_buff *skb, struct net_device *dev,
struct mctp_i2c_hdr *hdr;
struct mctp_hdr *mhdr;
u8 lldst, llsrc;
+ int rc;
if (len > MCTP_I2C_MAXMTU)
return -EMSGSIZE;
+ if (!daddr || !saddr)
+ return -EINVAL;
+
lldst = *((u8 *)daddr);
llsrc = *((u8 *)saddr);
+ rc = skb_cow_head(skb, sizeof(struct mctp_i2c_hdr));
+ if (rc)
+ return rc;
+
skb_push(skb, sizeof(struct mctp_i2c_hdr));
skb_reset_mac_header(skb);
hdr = (void *)skb_mac_header(skb);
@@ -836,7 +884,8 @@ static int mctp_i2c_add_netdev(struct mctp_i2c_client *mcli,
goto err;
}
- rc = mctp_register_netdev(ndev, &mctp_i2c_mctp_ops);
+ rc = mctp_register_netdev(ndev, &mctp_i2c_mctp_ops,
+ MCTP_PHYS_BINDING_SMBUS);
if (rc < 0) {
dev_err(&mcli->client->dev,
"register netdev \"%s\" failed %d\n",
@@ -1042,8 +1091,8 @@ static struct notifier_block mctp_i2c_notifier = {
};
static const struct i2c_device_id mctp_i2c_id[] = {
- { "mctp-i2c-interface", 0 },
- {},
+ { "mctp-i2c-interface" },
+ {}
};
MODULE_DEVICE_TABLE(i2c, mctp_i2c_id);
@@ -1058,7 +1107,7 @@ static struct i2c_driver mctp_i2c_driver = {
.name = "mctp-i2c-interface",
.of_match_table = mctp_i2c_of_match,
},
- .probe_new = mctp_i2c_probe,
+ .probe = mctp_i2c_probe,
.remove = mctp_i2c_remove,
.id_table = mctp_i2c_id,
};
diff --git a/drivers/net/mctp/mctp-i3c.c b/drivers/net/mctp/mctp-i3c.c
new file mode 100644
index 000000000000..36c2405677c2
--- /dev/null
+++ b/drivers/net/mctp/mctp-i3c.c
@@ -0,0 +1,767 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Implements DMTF specification
+ * "DSP0233 Management Component Transport Protocol (MCTP) I3C Transport
+ * Binding"
+ * https://www.dmtf.org/sites/default/files/standards/documents/DSP0233_1.0.0.pdf
+ *
+ * Copyright (c) 2023 Code Construct
+ */
+
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/i3c/device.h>
+#include <linux/i3c/master.h>
+#include <linux/if_arp.h>
+#include <linux/unaligned.h>
+#include <net/mctp.h>
+#include <net/mctpdevice.h>
+
+#define MCTP_I3C_MAXBUF 65536
+/* 48 bit Provisioned Id */
+#define PID_SIZE 6
+
+/* 64 byte payload, 4 byte MCTP header */
+static const int MCTP_I3C_MINMTU = 64 + 4;
+/* One byte less to allow for the PEC */
+static const int MCTP_I3C_MAXMTU = MCTP_I3C_MAXBUF - 1;
+/* 4 byte MCTP header, no data, 1 byte PEC */
+static const int MCTP_I3C_MINLEN = 4 + 1;
+
+/* Sufficient for 64kB at min mtu */
+static const int MCTP_I3C_TX_QUEUE_LEN = 1100;
+
+/* Somewhat arbitrary */
+static const int MCTP_I3C_IBI_SLOTS = 8;
+
+/* Mandatory Data Byte in an IBI, from DSP0233 */
+#define I3C_MDB_MCTP 0xAE
+/* From MIPI Device Characteristics Register (DCR) Assignments */
+#define I3C_DCR_MCTP 0xCC
+
+static const char *MCTP_I3C_OF_PROP = "mctp-controller";
+
+/* List of mctp_i3c_busdev */
+static LIST_HEAD(busdevs);
+/* Protects busdevs, as well as mctp_i3c_bus.devs lists */
+static DEFINE_MUTEX(busdevs_lock);
+
+struct mctp_i3c_bus {
+ struct net_device *ndev;
+
+ struct task_struct *tx_thread;
+ wait_queue_head_t tx_wq;
+ /* tx_lock protects tx_skb and devs */
+ spinlock_t tx_lock;
+ /* Next skb to transmit */
+ struct sk_buff *tx_skb;
+ /* Scratch buffer for xmit */
+ u8 tx_scratch[MCTP_I3C_MAXBUF];
+
+ /* Element of busdevs */
+ struct list_head list;
+
+ /* Provisioned ID of our controller */
+ u64 pid;
+
+ struct i3c_bus *bus;
+ /* Head of mctp_i3c_device.list. Protected by busdevs_lock */
+ struct list_head devs;
+};
+
+struct mctp_i3c_device {
+ struct i3c_device *i3c;
+ struct mctp_i3c_bus *mbus;
+ struct list_head list; /* Element of mctp_i3c_bus.devs */
+
+ /* Held while tx_thread is using this device */
+ struct mutex lock;
+
+ /* Whether BCR indicates MDB is present in IBI */
+ bool have_mdb;
+ /* I3C dynamic address */
+ u8 addr;
+ /* Maximum read length */
+ u16 mrl;
+ /* Maximum write length */
+ u16 mwl;
+ /* Provisioned ID */
+ u64 pid;
+};
+
+/* We synthesise a mac header using the Provisioned ID.
+ * Used to pass dest to mctp_i3c_start_xmit.
+ */
+struct mctp_i3c_internal_hdr {
+ u8 dest[PID_SIZE];
+ u8 source[PID_SIZE];
+} __packed;
+
+static int mctp_i3c_read(struct mctp_i3c_device *mi)
+{
+ struct i3c_xfer xfer = { .rnw = 1, .len = mi->mrl };
+ struct net_device_stats *stats = &mi->mbus->ndev->stats;
+ struct mctp_i3c_internal_hdr *ihdr = NULL;
+ struct sk_buff *skb = NULL;
+ struct mctp_skb_cb *cb;
+ int net_status, rc;
+ u8 pec, addr;
+
+ skb = netdev_alloc_skb(mi->mbus->ndev,
+ mi->mrl + sizeof(struct mctp_i3c_internal_hdr));
+ if (!skb) {
+ stats->rx_dropped++;
+ rc = -ENOMEM;
+ goto err;
+ }
+
+ skb->protocol = htons(ETH_P_MCTP);
+ /* Create a header for internal use */
+ skb_reset_mac_header(skb);
+ ihdr = skb_put(skb, sizeof(struct mctp_i3c_internal_hdr));
+ put_unaligned_be48(mi->pid, ihdr->source);
+ put_unaligned_be48(mi->mbus->pid, ihdr->dest);
+ skb_pull(skb, sizeof(struct mctp_i3c_internal_hdr));
+
+ xfer.data.in = skb_put(skb, mi->mrl);
+
+ /* Make sure netif_rx() is read in the same order as i3c. */
+ mutex_lock(&mi->lock);
+ rc = i3c_device_do_xfers(mi->i3c, &xfer, 1, I3C_SDR);
+ if (rc < 0)
+ goto err;
+
+ if (WARN_ON_ONCE(xfer.len > mi->mrl)) {
+ /* Bad i3c bus driver */
+ rc = -EIO;
+ goto err;
+ }
+ if (xfer.len < MCTP_I3C_MINLEN) {
+ stats->rx_length_errors++;
+ rc = -EIO;
+ goto err;
+ }
+
+ /* check PEC, including address byte */
+ addr = mi->addr << 1 | 1;
+ pec = i2c_smbus_pec(0, &addr, 1);
+ pec = i2c_smbus_pec(pec, xfer.data.in, xfer.len - 1);
+ if (pec != ((u8 *)xfer.data.in)[xfer.len - 1]) {
+ stats->rx_crc_errors++;
+ rc = -EINVAL;
+ goto err;
+ }
+
+ /* Remove PEC */
+ skb_trim(skb, xfer.len - 1);
+
+ cb = __mctp_cb(skb);
+ cb->halen = PID_SIZE;
+ put_unaligned_be48(mi->pid, cb->haddr);
+
+ net_status = netif_rx(skb);
+
+ if (net_status == NET_RX_SUCCESS) {
+ stats->rx_packets++;
+ stats->rx_bytes += xfer.len - 1;
+ } else {
+ stats->rx_dropped++;
+ }
+
+ mutex_unlock(&mi->lock);
+ return 0;
+err:
+ mutex_unlock(&mi->lock);
+ kfree_skb(skb);
+ return rc;
+}
+
+static void mctp_i3c_ibi_handler(struct i3c_device *i3c,
+ const struct i3c_ibi_payload *payload)
+{
+ struct mctp_i3c_device *mi = i3cdev_get_drvdata(i3c);
+
+ if (WARN_ON_ONCE(!mi))
+ return;
+
+ if (mi->have_mdb) {
+ if (payload->len > 0) {
+ if (((u8 *)payload->data)[0] != I3C_MDB_MCTP) {
+ /* Not a mctp-i3c interrupt, ignore it */
+ return;
+ }
+ } else {
+ /* The BCR advertised a Mandatory Data Byte but the
+ * device didn't send one.
+ */
+ dev_warn_once(i3cdev_to_dev(i3c), "IBI with missing MDB");
+ }
+ }
+
+ mctp_i3c_read(mi);
+}
+
+static int mctp_i3c_setup(struct mctp_i3c_device *mi)
+{
+ const struct i3c_ibi_setup ibi = {
+ .max_payload_len = 1,
+ .num_slots = MCTP_I3C_IBI_SLOTS,
+ .handler = mctp_i3c_ibi_handler,
+ };
+ struct i3c_device_info info;
+ int rc;
+
+ i3c_device_get_info(mi->i3c, &info);
+ mi->have_mdb = info.bcr & BIT(2);
+ mi->addr = info.dyn_addr;
+ mi->mwl = info.max_write_len;
+ mi->mrl = info.max_read_len;
+ mi->pid = info.pid;
+
+ rc = i3c_device_request_ibi(mi->i3c, &ibi);
+ if (rc == -ENOTSUPP) {
+ /* This driver only supports In-Band Interrupt mode.
+ * Support for Polling Mode could be added if required.
+ * (ENOTSUPP is from the i3c layer, not EOPNOTSUPP).
+ */
+ dev_warn(i3cdev_to_dev(mi->i3c),
+ "Failed, bus driver doesn't support In-Band Interrupts");
+ goto err;
+ } else if (rc < 0) {
+ dev_err(i3cdev_to_dev(mi->i3c),
+ "Failed requesting IBI (%d)\n", rc);
+ goto err;
+ }
+
+ rc = i3c_device_enable_ibi(mi->i3c);
+ if (rc < 0) {
+ /* Assume a driver supporting request_ibi also
+ * supports enable_ibi.
+ */
+ dev_err(i3cdev_to_dev(mi->i3c), "Failed enabling IBI (%d)\n", rc);
+ goto err_free_ibi;
+ }
+
+ return 0;
+
+err_free_ibi:
+ i3c_device_free_ibi(mi->i3c);
+
+err:
+ return rc;
+}
+
+/* Adds a new MCTP i3c_device to a bus */
+static int mctp_i3c_add_device(struct mctp_i3c_bus *mbus,
+ struct i3c_device *i3c)
+__must_hold(&busdevs_lock)
+{
+ struct mctp_i3c_device *mi = NULL;
+ int rc;
+
+ mi = kzalloc(sizeof(*mi), GFP_KERNEL);
+ if (!mi) {
+ rc = -ENOMEM;
+ goto err;
+ }
+ mi->mbus = mbus;
+ mi->i3c = i3c;
+ mutex_init(&mi->lock);
+ list_add(&mi->list, &mbus->devs);
+
+ i3cdev_set_drvdata(i3c, mi);
+ rc = mctp_i3c_setup(mi);
+ if (rc < 0)
+ goto err_free;
+
+ return 0;
+
+err_free:
+ list_del(&mi->list);
+ kfree(mi);
+
+err:
+ dev_warn(i3cdev_to_dev(i3c), "Error adding mctp-i3c device, %d\n", rc);
+ return rc;
+}
+
+static int mctp_i3c_probe(struct i3c_device *i3c)
+{
+ struct mctp_i3c_bus *b = NULL, *mbus = NULL;
+
+ /* Look for a known bus */
+ mutex_lock(&busdevs_lock);
+ list_for_each_entry(b, &busdevs, list)
+ if (b->bus == i3c->bus) {
+ mbus = b;
+ break;
+ }
+ mutex_unlock(&busdevs_lock);
+
+ if (!mbus) {
+ /* probably no "mctp-controller" property on the i3c bus */
+ return -ENODEV;
+ }
+
+ return mctp_i3c_add_device(mbus, i3c);
+}
+
+static void mctp_i3c_remove_device(struct mctp_i3c_device *mi)
+__must_hold(&busdevs_lock)
+{
+ /* Ensure the tx thread isn't using the device */
+ mutex_lock(&mi->lock);
+
+ /* Counterpart of mctp_i3c_setup */
+ i3c_device_disable_ibi(mi->i3c);
+ i3c_device_free_ibi(mi->i3c);
+
+ /* Counterpart of mctp_i3c_add_device */
+ i3cdev_set_drvdata(mi->i3c, NULL);
+ list_del(&mi->list);
+
+ /* Safe to unlock after removing from the list */
+ mutex_unlock(&mi->lock);
+ kfree(mi);
+}
+
+static void mctp_i3c_remove(struct i3c_device *i3c)
+{
+ struct mctp_i3c_device *mi = i3cdev_get_drvdata(i3c);
+
+ /* We my have received a Bus Remove notify prior to device remove,
+ * so mi will already be removed.
+ */
+ if (!mi)
+ return;
+
+ mutex_lock(&busdevs_lock);
+ mctp_i3c_remove_device(mi);
+ mutex_unlock(&busdevs_lock);
+}
+
+/* Returns the device for an address, with mi->lock held */
+static struct mctp_i3c_device *
+mctp_i3c_lookup(struct mctp_i3c_bus *mbus, u64 pid)
+{
+ struct mctp_i3c_device *mi = NULL, *ret = NULL;
+
+ mutex_lock(&busdevs_lock);
+ list_for_each_entry(mi, &mbus->devs, list)
+ if (mi->pid == pid) {
+ ret = mi;
+ mutex_lock(&mi->lock);
+ break;
+ }
+ mutex_unlock(&busdevs_lock);
+ return ret;
+}
+
+static void mctp_i3c_xmit(struct mctp_i3c_bus *mbus, struct sk_buff *skb)
+{
+ struct net_device_stats *stats = &mbus->ndev->stats;
+ struct i3c_xfer xfer = { .rnw = false };
+ struct mctp_i3c_internal_hdr *ihdr = NULL;
+ struct mctp_i3c_device *mi = NULL;
+ unsigned int data_len;
+ u8 *data = NULL;
+ u8 addr, pec;
+ int rc = 0;
+ u64 pid;
+
+ skb_pull(skb, sizeof(struct mctp_i3c_internal_hdr));
+ data_len = skb->len;
+
+ ihdr = (void *)skb_mac_header(skb);
+
+ pid = get_unaligned_be48(ihdr->dest);
+ mi = mctp_i3c_lookup(mbus, pid);
+ if (!mi) {
+ /* I3C endpoint went away after the packet was enqueued? */
+ stats->tx_dropped++;
+ goto out;
+ }
+
+ if (WARN_ON_ONCE(data_len + 1 > MCTP_I3C_MAXBUF))
+ goto out;
+
+ if (data_len + 1 > (unsigned int)mi->mwl) {
+ /* Route MTU was larger than supported by the endpoint */
+ stats->tx_dropped++;
+ goto out;
+ }
+
+ /* Need a linear buffer with space for the PEC */
+ xfer.len = data_len + 1;
+ if (skb_tailroom(skb) >= 1) {
+ skb_put(skb, 1);
+ data = skb->data;
+ } else {
+ /* Otherwise need to copy the buffer */
+ skb_copy_bits(skb, 0, mbus->tx_scratch, skb->len);
+ data = mbus->tx_scratch;
+ }
+
+ /* PEC calculation */
+ addr = mi->addr << 1;
+ pec = i2c_smbus_pec(0, &addr, 1);
+ pec = i2c_smbus_pec(pec, data, data_len);
+ data[data_len] = pec;
+
+ xfer.data.out = data;
+ rc = i3c_device_do_xfers(mi->i3c, &xfer, 1, I3C_SDR);
+ if (rc == 0) {
+ stats->tx_bytes += data_len;
+ stats->tx_packets++;
+ } else {
+ stats->tx_errors++;
+ }
+
+out:
+ if (mi)
+ mutex_unlock(&mi->lock);
+}
+
+static int mctp_i3c_tx_thread(void *data)
+{
+ struct mctp_i3c_bus *mbus = data;
+ struct sk_buff *skb;
+
+ for (;;) {
+ if (kthread_should_stop())
+ break;
+
+ spin_lock_bh(&mbus->tx_lock);
+ skb = mbus->tx_skb;
+ mbus->tx_skb = NULL;
+ spin_unlock_bh(&mbus->tx_lock);
+
+ if (netif_queue_stopped(mbus->ndev))
+ netif_wake_queue(mbus->ndev);
+
+ if (skb) {
+ mctp_i3c_xmit(mbus, skb);
+ kfree_skb(skb);
+ } else {
+ wait_event_idle(mbus->tx_wq,
+ mbus->tx_skb || kthread_should_stop());
+ }
+ }
+
+ return 0;
+}
+
+static netdev_tx_t mctp_i3c_start_xmit(struct sk_buff *skb,
+ struct net_device *ndev)
+{
+ struct mctp_i3c_bus *mbus = netdev_priv(ndev);
+ netdev_tx_t ret;
+
+ spin_lock(&mbus->tx_lock);
+ netif_stop_queue(ndev);
+ if (mbus->tx_skb) {
+ dev_warn_ratelimited(&ndev->dev, "TX with queue stopped");
+ ret = NETDEV_TX_BUSY;
+ } else {
+ mbus->tx_skb = skb;
+ ret = NETDEV_TX_OK;
+ }
+ spin_unlock(&mbus->tx_lock);
+
+ if (ret == NETDEV_TX_OK)
+ wake_up(&mbus->tx_wq);
+
+ return ret;
+}
+
+static void mctp_i3c_bus_free(struct mctp_i3c_bus *mbus)
+__must_hold(&busdevs_lock)
+{
+ struct mctp_i3c_device *mi = NULL, *tmp = NULL;
+
+ if (mbus->tx_thread) {
+ kthread_stop(mbus->tx_thread);
+ mbus->tx_thread = NULL;
+ }
+
+ /* Remove any child devices */
+ list_for_each_entry_safe(mi, tmp, &mbus->devs, list) {
+ mctp_i3c_remove_device(mi);
+ }
+
+ kfree_skb(mbus->tx_skb);
+ list_del(&mbus->list);
+}
+
+static void mctp_i3c_ndo_uninit(struct net_device *ndev)
+{
+ struct mctp_i3c_bus *mbus = netdev_priv(ndev);
+
+ /* Perform cleanup here to ensure there are no remaining references */
+ mctp_i3c_bus_free(mbus);
+}
+
+static int mctp_i3c_header_create(struct sk_buff *skb, struct net_device *dev,
+ unsigned short type, const void *daddr,
+ const void *saddr, unsigned int len)
+{
+ struct mctp_i3c_internal_hdr *ihdr;
+ int rc;
+
+ if (!daddr || !saddr)
+ return -EINVAL;
+
+ rc = skb_cow_head(skb, sizeof(struct mctp_i3c_internal_hdr));
+ if (rc)
+ return rc;
+
+ skb_push(skb, sizeof(struct mctp_i3c_internal_hdr));
+ skb_reset_mac_header(skb);
+ ihdr = (void *)skb_mac_header(skb);
+ memcpy(ihdr->dest, daddr, PID_SIZE);
+ memcpy(ihdr->source, saddr, PID_SIZE);
+ return 0;
+}
+
+static const struct net_device_ops mctp_i3c_ops = {
+ .ndo_start_xmit = mctp_i3c_start_xmit,
+ .ndo_uninit = mctp_i3c_ndo_uninit,
+};
+
+static const struct header_ops mctp_i3c_headops = {
+ .create = mctp_i3c_header_create,
+};
+
+static void mctp_i3c_net_setup(struct net_device *dev)
+{
+ dev->type = ARPHRD_MCTP;
+
+ dev->mtu = MCTP_I3C_MAXMTU;
+ dev->min_mtu = MCTP_I3C_MINMTU;
+ dev->max_mtu = MCTP_I3C_MAXMTU;
+ dev->tx_queue_len = MCTP_I3C_TX_QUEUE_LEN;
+
+ dev->hard_header_len = sizeof(struct mctp_i3c_internal_hdr);
+ dev->addr_len = PID_SIZE;
+
+ dev->netdev_ops = &mctp_i3c_ops;
+ dev->header_ops = &mctp_i3c_headops;
+}
+
+static bool mctp_i3c_is_mctp_controller(struct i3c_bus *bus)
+{
+ struct i3c_dev_desc *master = bus->cur_master;
+
+ if (!master)
+ return false;
+
+ return of_property_read_bool(master->common.master->dev.of_node,
+ MCTP_I3C_OF_PROP);
+}
+
+/* Returns the Provisioned Id of a local bus master */
+static int mctp_i3c_bus_local_pid(struct i3c_bus *bus, u64 *ret_pid)
+{
+ struct i3c_dev_desc *master;
+
+ master = bus->cur_master;
+ if (WARN_ON_ONCE(!master))
+ return -ENOENT;
+ *ret_pid = master->info.pid;
+
+ return 0;
+}
+
+/* Returns an ERR_PTR on failure */
+static struct mctp_i3c_bus *mctp_i3c_bus_add(struct i3c_bus *bus)
+__must_hold(&busdevs_lock)
+{
+ struct mctp_i3c_bus *mbus = NULL;
+ struct net_device *ndev = NULL;
+ char namebuf[IFNAMSIZ];
+ u8 addr[PID_SIZE];
+ int rc;
+
+ if (!mctp_i3c_is_mctp_controller(bus))
+ return ERR_PTR(-ENOENT);
+
+ snprintf(namebuf, sizeof(namebuf), "mctpi3c%d", bus->id);
+ ndev = alloc_netdev(sizeof(*mbus), namebuf, NET_NAME_ENUM,
+ mctp_i3c_net_setup);
+ if (!ndev) {
+ rc = -ENOMEM;
+ goto err;
+ }
+
+ mbus = netdev_priv(ndev);
+ mbus->ndev = ndev;
+ mbus->bus = bus;
+ INIT_LIST_HEAD(&mbus->devs);
+ list_add(&mbus->list, &busdevs);
+
+ rc = mctp_i3c_bus_local_pid(bus, &mbus->pid);
+ if (rc < 0) {
+ dev_err(&ndev->dev, "No I3C PID available\n");
+ goto err_free_uninit;
+ }
+ put_unaligned_be48(mbus->pid, addr);
+ dev_addr_set(ndev, addr);
+
+ init_waitqueue_head(&mbus->tx_wq);
+ spin_lock_init(&mbus->tx_lock);
+ mbus->tx_thread = kthread_run(mctp_i3c_tx_thread, mbus,
+ "%s/tx", ndev->name);
+ if (IS_ERR(mbus->tx_thread)) {
+ dev_warn(&ndev->dev, "Error creating thread: %pe\n",
+ mbus->tx_thread);
+ rc = PTR_ERR(mbus->tx_thread);
+ mbus->tx_thread = NULL;
+ goto err_free_uninit;
+ }
+
+ rc = mctp_register_netdev(ndev, NULL, MCTP_PHYS_BINDING_I3C);
+ if (rc < 0) {
+ dev_warn(&ndev->dev, "netdev register failed: %d\n", rc);
+ goto err_free_netdev;
+ }
+ return mbus;
+
+err_free_uninit:
+ /* uninit will not get called if a netdev has not been registered,
+ * so we perform the same mbus cleanup manually.
+ */
+ mctp_i3c_bus_free(mbus);
+
+err_free_netdev:
+ free_netdev(ndev);
+
+err:
+ return ERR_PTR(rc);
+}
+
+static void mctp_i3c_bus_remove(struct mctp_i3c_bus *mbus)
+__must_hold(&busdevs_lock)
+{
+ /* Unregister calls through to ndo_uninit -> mctp_i3c_bus_free() */
+ mctp_unregister_netdev(mbus->ndev);
+
+ free_netdev(mbus->ndev);
+ /* mbus is deallocated */
+}
+
+/* Removes all mctp-i3c busses */
+static void mctp_i3c_bus_remove_all(void)
+{
+ struct mctp_i3c_bus *mbus = NULL, *tmp = NULL;
+
+ mutex_lock(&busdevs_lock);
+ list_for_each_entry_safe(mbus, tmp, &busdevs, list) {
+ mctp_i3c_bus_remove(mbus);
+ }
+ mutex_unlock(&busdevs_lock);
+}
+
+/* Adds a i3c_bus if it isn't already in the busdevs list.
+ * Suitable as an i3c_for_each_bus_locked callback.
+ */
+static int mctp_i3c_bus_add_new(struct i3c_bus *bus, void *data)
+{
+ struct mctp_i3c_bus *mbus = NULL, *tmp = NULL;
+ bool exists = false;
+
+ mutex_lock(&busdevs_lock);
+ list_for_each_entry_safe(mbus, tmp, &busdevs, list)
+ if (mbus->bus == bus)
+ exists = true;
+
+ /* It is OK for a bus to already exist. That can occur due to
+ * the race in mod_init between notifier and for_each_bus
+ */
+ if (!exists)
+ mctp_i3c_bus_add(bus);
+ mutex_unlock(&busdevs_lock);
+ return 0;
+}
+
+static void mctp_i3c_notify_bus_remove(struct i3c_bus *bus)
+{
+ struct mctp_i3c_bus *mbus = NULL, *tmp;
+
+ mutex_lock(&busdevs_lock);
+ list_for_each_entry_safe(mbus, tmp, &busdevs, list)
+ if (mbus->bus == bus)
+ mctp_i3c_bus_remove(mbus);
+ mutex_unlock(&busdevs_lock);
+}
+
+static int mctp_i3c_notifier_call(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ switch (action) {
+ case I3C_NOTIFY_BUS_ADD:
+ mctp_i3c_bus_add_new((struct i3c_bus *)data, NULL);
+ break;
+ case I3C_NOTIFY_BUS_REMOVE:
+ mctp_i3c_notify_bus_remove((struct i3c_bus *)data);
+ break;
+ }
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block mctp_i3c_notifier = {
+ .notifier_call = mctp_i3c_notifier_call,
+};
+
+static const struct i3c_device_id mctp_i3c_ids[] = {
+ I3C_CLASS(I3C_DCR_MCTP, NULL),
+ { 0 },
+};
+
+static struct i3c_driver mctp_i3c_driver = {
+ .driver = {
+ .name = "mctp-i3c",
+ },
+ .probe = mctp_i3c_probe,
+ .remove = mctp_i3c_remove,
+ .id_table = mctp_i3c_ids,
+};
+
+static __init int mctp_i3c_mod_init(void)
+{
+ int rc;
+
+ rc = i3c_register_notifier(&mctp_i3c_notifier);
+ if (rc < 0) {
+ i3c_driver_unregister(&mctp_i3c_driver);
+ return rc;
+ }
+
+ i3c_for_each_bus_locked(mctp_i3c_bus_add_new, NULL);
+
+ rc = i3c_driver_register(&mctp_i3c_driver);
+ if (rc < 0)
+ return rc;
+
+ return 0;
+}
+
+static __exit void mctp_i3c_mod_exit(void)
+{
+ int rc;
+
+ i3c_driver_unregister(&mctp_i3c_driver);
+
+ rc = i3c_unregister_notifier(&mctp_i3c_notifier);
+ if (rc < 0)
+ pr_warn("MCTP I3C could not unregister notifier, %d\n", rc);
+
+ mctp_i3c_bus_remove_all();
+}
+
+module_init(mctp_i3c_mod_init);
+module_exit(mctp_i3c_mod_exit);
+
+MODULE_DEVICE_TABLE(i3c, mctp_i3c_ids);
+MODULE_DESCRIPTION("MCTP I3C device");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Matt Johnston <matt@codeconstruct.com.au>");
diff --git a/drivers/net/mctp/mctp-serial.c b/drivers/net/mctp/mctp-serial.c
index 9f9eaf896047..26c9a33fd636 100644
--- a/drivers/net/mctp/mctp-serial.c
+++ b/drivers/net/mctp/mctp-serial.c
@@ -23,6 +23,7 @@
#include <linux/mctp.h>
#include <net/mctp.h>
+#include <net/mctpdevice.h>
#include <net/pkt_sched.h>
#define MCTP_SERIAL_MTU 68 /* base mtu (64) + mctp header */
@@ -64,18 +65,18 @@ struct mctp_serial {
u16 txfcs, rxfcs, rxfcs_rcvd;
unsigned int txlen, rxlen;
unsigned int txpos, rxpos;
- unsigned char txbuf[BUFSIZE],
+ u8 txbuf[BUFSIZE],
rxbuf[BUFSIZE];
};
-static bool needs_escape(unsigned char c)
+static bool needs_escape(u8 c)
{
return c == BYTE_ESC || c == BYTE_FRAME;
}
-static int next_chunk_len(struct mctp_serial *dev)
+static unsigned int next_chunk_len(struct mctp_serial *dev)
{
- int i;
+ unsigned int i;
/* either we have no bytes to send ... */
if (dev->txpos == dev->txlen)
@@ -91,15 +92,15 @@ static int next_chunk_len(struct mctp_serial *dev)
* will be those non-escaped bytes, and does not include the escaped
* byte.
*/
- for (i = 1; i + dev->txpos + 1 < dev->txlen; i++) {
- if (needs_escape(dev->txbuf[dev->txpos + i + 1]))
+ for (i = 1; i + dev->txpos < dev->txlen; i++) {
+ if (needs_escape(dev->txbuf[dev->txpos + i]))
break;
}
return i;
}
-static int write_chunk(struct mctp_serial *dev, unsigned char *buf, int len)
+static ssize_t write_chunk(struct mctp_serial *dev, u8 *buf, size_t len)
{
return dev->tty->ops->write(dev->tty, buf, len);
}
@@ -108,9 +109,10 @@ static void mctp_serial_tx_work(struct work_struct *work)
{
struct mctp_serial *dev = container_of(work, struct mctp_serial,
tx_work);
- unsigned char c, buf[3];
unsigned long flags;
- int len, txlen;
+ ssize_t txlen;
+ unsigned int len;
+ u8 c, buf[3];
spin_lock_irqsave(&dev->lock, flags);
@@ -293,7 +295,7 @@ static void mctp_serial_rx(struct mctp_serial *dev)
dev->netdev->stats.rx_bytes += dev->rxlen;
}
-static void mctp_serial_push_header(struct mctp_serial *dev, unsigned char c)
+static void mctp_serial_push_header(struct mctp_serial *dev, u8 c)
{
switch (dev->rxpos) {
case 0:
@@ -323,7 +325,7 @@ static void mctp_serial_push_header(struct mctp_serial *dev, unsigned char c)
}
}
-static void mctp_serial_push_trailer(struct mctp_serial *dev, unsigned char c)
+static void mctp_serial_push_trailer(struct mctp_serial *dev, u8 c)
{
switch (dev->rxpos) {
case 0:
@@ -347,7 +349,7 @@ static void mctp_serial_push_trailer(struct mctp_serial *dev, unsigned char c)
}
}
-static void mctp_serial_push(struct mctp_serial *dev, unsigned char c)
+static void mctp_serial_push(struct mctp_serial *dev, u8 c)
{
switch (dev->rxstate) {
case STATE_IDLE:
@@ -390,12 +392,11 @@ static void mctp_serial_push(struct mctp_serial *dev, unsigned char c)
}
}
-static void mctp_serial_tty_receive_buf(struct tty_struct *tty,
- const unsigned char *c,
- const char *f, int len)
+static void mctp_serial_tty_receive_buf(struct tty_struct *tty, const u8 *c,
+ const u8 *f, size_t len)
{
struct mctp_serial *dev = tty->disc_data;
- int i;
+ size_t i;
if (!netif_running(dev->netdev))
return;
@@ -470,7 +471,7 @@ static int mctp_serial_open(struct tty_struct *tty)
spin_lock_init(&dev->lock);
INIT_WORK(&dev->tx_work, mctp_serial_tx_work);
- rc = register_netdev(ndev);
+ rc = mctp_register_netdev(ndev, NULL, MCTP_PHYS_BINDING_SERIAL);
if (rc)
goto free_netdev;
@@ -492,7 +493,7 @@ static void mctp_serial_close(struct tty_struct *tty)
struct mctp_serial *dev = tty->disc_data;
int idx = dev->idx;
- unregister_netdev(dev->netdev);
+ mctp_unregister_netdev(dev->netdev);
ida_free(&mctp_serial_ida, idx);
}
@@ -522,3 +523,112 @@ module_exit(mctp_serial_exit);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Jeremy Kerr <jk@codeconstruct.com.au>");
MODULE_DESCRIPTION("MCTP Serial transport");
+
+#if IS_ENABLED(CONFIG_MCTP_SERIAL_TEST)
+#include <kunit/test.h>
+
+#define MAX_CHUNKS 6
+struct test_chunk_tx {
+ u8 input_len;
+ u8 input[MCTP_SERIAL_MTU];
+ u8 chunks[MAX_CHUNKS];
+};
+
+static void test_next_chunk_len(struct kunit *test)
+{
+ struct mctp_serial devx;
+ struct mctp_serial *dev = &devx;
+ int next;
+
+ const struct test_chunk_tx *params = test->param_value;
+
+ memset(dev, 0x0, sizeof(*dev));
+ memcpy(dev->txbuf, params->input, params->input_len);
+ dev->txlen = params->input_len;
+
+ for (size_t i = 0; i < MAX_CHUNKS; i++) {
+ next = next_chunk_len(dev);
+ dev->txpos += next;
+ KUNIT_EXPECT_EQ(test, next, params->chunks[i]);
+
+ if (next == 0) {
+ KUNIT_EXPECT_EQ(test, dev->txpos, dev->txlen);
+ return;
+ }
+ }
+
+ KUNIT_FAIL_AND_ABORT(test, "Ran out of chunks");
+}
+
+static struct test_chunk_tx chunk_tx_tests[] = {
+ {
+ .input_len = 5,
+ .input = { 0x00, 0x11, 0x22, 0x7e, 0x80 },
+ .chunks = { 3, 1, 1, 0},
+ },
+ {
+ .input_len = 5,
+ .input = { 0x00, 0x11, 0x22, 0x7e, 0x7d },
+ .chunks = { 3, 1, 1, 0},
+ },
+ {
+ .input_len = 3,
+ .input = { 0x7e, 0x11, 0x22, },
+ .chunks = { 1, 2, 0},
+ },
+ {
+ .input_len = 3,
+ .input = { 0x7e, 0x7e, 0x7d, },
+ .chunks = { 1, 1, 1, 0},
+ },
+ {
+ .input_len = 4,
+ .input = { 0x7e, 0x7e, 0x00, 0x7d, },
+ .chunks = { 1, 1, 1, 1, 0},
+ },
+ {
+ .input_len = 6,
+ .input = { 0x7e, 0x7e, 0x00, 0x7d, 0x10, 0x10},
+ .chunks = { 1, 1, 1, 1, 2, 0},
+ },
+ {
+ .input_len = 1,
+ .input = { 0x7e },
+ .chunks = { 1, 0 },
+ },
+ {
+ .input_len = 1,
+ .input = { 0x80 },
+ .chunks = { 1, 0 },
+ },
+ {
+ .input_len = 3,
+ .input = { 0x80, 0x80, 0x00 },
+ .chunks = { 3, 0 },
+ },
+ {
+ .input_len = 7,
+ .input = { 0x01, 0x00, 0x08, 0xc8, 0x00, 0x80, 0x02 },
+ .chunks = { 7, 0 },
+ },
+ {
+ .input_len = 7,
+ .input = { 0x01, 0x00, 0x08, 0xc8, 0x7e, 0x80, 0x02 },
+ .chunks = { 4, 1, 2, 0 },
+ },
+};
+
+KUNIT_ARRAY_PARAM(chunk_tx, chunk_tx_tests, NULL);
+
+static struct kunit_case mctp_serial_test_cases[] = {
+ KUNIT_CASE_PARAM(test_next_chunk_len, chunk_tx_gen_params),
+};
+
+static struct kunit_suite mctp_serial_test_suite = {
+ .name = "mctp_serial",
+ .test_cases = mctp_serial_test_cases,
+};
+
+kunit_test_suite(mctp_serial_test_suite);
+
+#endif /* CONFIG_MCTP_SERIAL_TEST */
diff --git a/drivers/net/mctp/mctp-usb.c b/drivers/net/mctp/mctp-usb.c
new file mode 100644
index 000000000000..ef860cfc629f
--- /dev/null
+++ b/drivers/net/mctp/mctp-usb.c
@@ -0,0 +1,390 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * mctp-usb.c - MCTP-over-USB (DMTF DSP0283) transport binding driver.
+ *
+ * DSP0283 is available at:
+ * https://www.dmtf.org/sites/default/files/standards/documents/DSP0283_1.0.1.pdf
+ *
+ * Copyright (C) 2024-2025 Code Construct Pty Ltd
+ */
+
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/usb.h>
+#include <linux/usb/mctp-usb.h>
+
+#include <net/mctp.h>
+#include <net/mctpdevice.h>
+#include <net/pkt_sched.h>
+
+#include <uapi/linux/if_arp.h>
+
+struct mctp_usb {
+ struct usb_device *usbdev;
+ struct usb_interface *intf;
+ bool stopped;
+
+ struct net_device *netdev;
+
+ u8 ep_in;
+ u8 ep_out;
+
+ struct urb *tx_urb;
+ struct urb *rx_urb;
+
+ struct delayed_work rx_retry_work;
+};
+
+static void mctp_usb_out_complete(struct urb *urb)
+{
+ struct sk_buff *skb = urb->context;
+ struct net_device *netdev = skb->dev;
+ int status;
+
+ status = urb->status;
+
+ switch (status) {
+ case -ENOENT:
+ case -ECONNRESET:
+ case -ESHUTDOWN:
+ case -EPROTO:
+ dev_dstats_tx_dropped(netdev);
+ break;
+ case 0:
+ dev_dstats_tx_add(netdev, skb->len);
+ netif_wake_queue(netdev);
+ consume_skb(skb);
+ return;
+ default:
+ netdev_dbg(netdev, "unexpected tx urb status: %d\n", status);
+ dev_dstats_tx_dropped(netdev);
+ }
+
+ kfree_skb(skb);
+}
+
+static netdev_tx_t mctp_usb_start_xmit(struct sk_buff *skb,
+ struct net_device *dev)
+{
+ struct mctp_usb *mctp_usb = netdev_priv(dev);
+ struct mctp_usb_hdr *hdr;
+ unsigned int plen;
+ struct urb *urb;
+ int rc;
+
+ plen = skb->len;
+
+ if (plen + sizeof(*hdr) > MCTP_USB_XFER_SIZE)
+ goto err_drop;
+
+ rc = skb_cow_head(skb, sizeof(*hdr));
+ if (rc)
+ goto err_drop;
+
+ hdr = skb_push(skb, sizeof(*hdr));
+ if (!hdr)
+ goto err_drop;
+
+ hdr->id = cpu_to_be16(MCTP_USB_DMTF_ID);
+ hdr->rsvd = 0;
+ hdr->len = plen + sizeof(*hdr);
+
+ urb = mctp_usb->tx_urb;
+
+ usb_fill_bulk_urb(urb, mctp_usb->usbdev,
+ usb_sndbulkpipe(mctp_usb->usbdev, mctp_usb->ep_out),
+ skb->data, skb->len,
+ mctp_usb_out_complete, skb);
+
+ /* Stops TX queue first to prevent race condition with URB complete */
+ netif_stop_queue(dev);
+ rc = usb_submit_urb(urb, GFP_ATOMIC);
+ if (rc) {
+ netif_wake_queue(dev);
+ goto err_drop;
+ }
+
+ return NETDEV_TX_OK;
+
+err_drop:
+ dev_dstats_tx_dropped(dev);
+ kfree_skb(skb);
+ return NETDEV_TX_OK;
+}
+
+static void mctp_usb_in_complete(struct urb *urb);
+
+/* If we fail to queue an in urb atomically (either due to skb allocation or
+ * urb submission), we will schedule a rx queue in nonatomic context
+ * after a delay, specified in jiffies
+ */
+static const unsigned long RX_RETRY_DELAY = HZ / 4;
+
+static int mctp_usb_rx_queue(struct mctp_usb *mctp_usb, gfp_t gfp)
+{
+ struct sk_buff *skb;
+ int rc;
+
+ skb = __netdev_alloc_skb(mctp_usb->netdev, MCTP_USB_XFER_SIZE, gfp);
+ if (!skb) {
+ rc = -ENOMEM;
+ goto err_retry;
+ }
+
+ usb_fill_bulk_urb(mctp_usb->rx_urb, mctp_usb->usbdev,
+ usb_rcvbulkpipe(mctp_usb->usbdev, mctp_usb->ep_in),
+ skb->data, MCTP_USB_XFER_SIZE,
+ mctp_usb_in_complete, skb);
+
+ rc = usb_submit_urb(mctp_usb->rx_urb, gfp);
+ if (rc) {
+ netdev_dbg(mctp_usb->netdev, "rx urb submit failure: %d\n", rc);
+ kfree_skb(skb);
+ if (rc == -ENOMEM)
+ goto err_retry;
+ }
+
+ return rc;
+
+err_retry:
+ schedule_delayed_work(&mctp_usb->rx_retry_work, RX_RETRY_DELAY);
+ return rc;
+}
+
+static void mctp_usb_in_complete(struct urb *urb)
+{
+ struct sk_buff *skb = urb->context;
+ struct net_device *netdev = skb->dev;
+ struct mctp_usb *mctp_usb = netdev_priv(netdev);
+ struct mctp_skb_cb *cb;
+ unsigned int len;
+ int status;
+
+ status = urb->status;
+
+ switch (status) {
+ case -ENOENT:
+ case -ECONNRESET:
+ case -ESHUTDOWN:
+ case -EPROTO:
+ kfree_skb(skb);
+ return;
+ case 0:
+ break;
+ default:
+ netdev_dbg(netdev, "unexpected rx urb status: %d\n", status);
+ kfree_skb(skb);
+ return;
+ }
+
+ len = urb->actual_length;
+ __skb_put(skb, len);
+
+ while (skb) {
+ struct sk_buff *skb2 = NULL;
+ struct mctp_usb_hdr *hdr;
+ u8 pkt_len; /* length of MCTP packet, no USB header */
+
+ skb_reset_mac_header(skb);
+ hdr = skb_pull_data(skb, sizeof(*hdr));
+ if (!hdr)
+ break;
+
+ if (be16_to_cpu(hdr->id) != MCTP_USB_DMTF_ID) {
+ netdev_dbg(netdev, "rx: invalid id %04x\n",
+ be16_to_cpu(hdr->id));
+ break;
+ }
+
+ if (hdr->len <
+ sizeof(struct mctp_hdr) + sizeof(struct mctp_usb_hdr)) {
+ netdev_dbg(netdev, "rx: short packet (hdr) %d\n",
+ hdr->len);
+ break;
+ }
+
+ /* we know we have at least sizeof(struct mctp_usb_hdr) here */
+ pkt_len = hdr->len - sizeof(struct mctp_usb_hdr);
+ if (pkt_len > skb->len) {
+ netdev_dbg(netdev,
+ "rx: short packet (xfer) %d, actual %d\n",
+ hdr->len, skb->len);
+ break;
+ }
+
+ if (pkt_len < skb->len) {
+ /* more packets may follow - clone to a new
+ * skb to use on the next iteration
+ */
+ skb2 = skb_clone(skb, GFP_ATOMIC);
+ if (skb2) {
+ if (!skb_pull(skb2, pkt_len)) {
+ kfree_skb(skb2);
+ skb2 = NULL;
+ }
+ }
+ skb_trim(skb, pkt_len);
+ }
+
+ dev_dstats_rx_add(netdev, skb->len);
+
+ skb->protocol = htons(ETH_P_MCTP);
+ skb_reset_network_header(skb);
+ cb = __mctp_cb(skb);
+ cb->halen = 0;
+ netif_rx(skb);
+
+ skb = skb2;
+ }
+
+ if (skb)
+ kfree_skb(skb);
+
+ mctp_usb_rx_queue(mctp_usb, GFP_ATOMIC);
+}
+
+static void mctp_usb_rx_retry_work(struct work_struct *work)
+{
+ struct mctp_usb *mctp_usb = container_of(work, struct mctp_usb,
+ rx_retry_work.work);
+
+ if (READ_ONCE(mctp_usb->stopped))
+ return;
+
+ mctp_usb_rx_queue(mctp_usb, GFP_KERNEL);
+}
+
+static int mctp_usb_open(struct net_device *dev)
+{
+ struct mctp_usb *mctp_usb = netdev_priv(dev);
+
+ WRITE_ONCE(mctp_usb->stopped, false);
+
+ netif_start_queue(dev);
+
+ return mctp_usb_rx_queue(mctp_usb, GFP_KERNEL);
+}
+
+static int mctp_usb_stop(struct net_device *dev)
+{
+ struct mctp_usb *mctp_usb = netdev_priv(dev);
+
+ netif_stop_queue(dev);
+
+ /* prevent RX submission retry */
+ WRITE_ONCE(mctp_usb->stopped, true);
+
+ usb_kill_urb(mctp_usb->rx_urb);
+ usb_kill_urb(mctp_usb->tx_urb);
+
+ cancel_delayed_work_sync(&mctp_usb->rx_retry_work);
+
+ return 0;
+}
+
+static const struct net_device_ops mctp_usb_netdev_ops = {
+ .ndo_start_xmit = mctp_usb_start_xmit,
+ .ndo_open = mctp_usb_open,
+ .ndo_stop = mctp_usb_stop,
+};
+
+static void mctp_usb_netdev_setup(struct net_device *dev)
+{
+ dev->type = ARPHRD_MCTP;
+
+ dev->mtu = MCTP_USB_MTU_MIN;
+ dev->min_mtu = MCTP_USB_MTU_MIN;
+ dev->max_mtu = MCTP_USB_MTU_MAX;
+
+ dev->hard_header_len = sizeof(struct mctp_usb_hdr);
+ dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
+ dev->flags = IFF_NOARP;
+ dev->netdev_ops = &mctp_usb_netdev_ops;
+ dev->pcpu_stat_type = NETDEV_PCPU_STAT_DSTATS;
+}
+
+static int mctp_usb_probe(struct usb_interface *intf,
+ const struct usb_device_id *id)
+{
+ struct usb_endpoint_descriptor *ep_in, *ep_out;
+ struct usb_host_interface *iface_desc;
+ struct net_device *netdev;
+ struct mctp_usb *dev;
+ int rc;
+
+ /* only one alternate */
+ iface_desc = intf->cur_altsetting;
+
+ rc = usb_find_common_endpoints(iface_desc, &ep_in, &ep_out, NULL, NULL);
+ if (rc) {
+ dev_err(&intf->dev, "invalid endpoints on device?\n");
+ return rc;
+ }
+
+ netdev = alloc_netdev(sizeof(*dev), "mctpusb%d", NET_NAME_ENUM,
+ mctp_usb_netdev_setup);
+ if (!netdev)
+ return -ENOMEM;
+
+ SET_NETDEV_DEV(netdev, &intf->dev);
+ dev = netdev_priv(netdev);
+ dev->netdev = netdev;
+ dev->usbdev = usb_get_dev(interface_to_usbdev(intf));
+ dev->intf = intf;
+ usb_set_intfdata(intf, dev);
+
+ dev->ep_in = ep_in->bEndpointAddress;
+ dev->ep_out = ep_out->bEndpointAddress;
+
+ dev->tx_urb = usb_alloc_urb(0, GFP_KERNEL);
+ dev->rx_urb = usb_alloc_urb(0, GFP_KERNEL);
+ if (!dev->tx_urb || !dev->rx_urb) {
+ rc = -ENOMEM;
+ goto err_free_urbs;
+ }
+
+ INIT_DELAYED_WORK(&dev->rx_retry_work, mctp_usb_rx_retry_work);
+
+ rc = mctp_register_netdev(netdev, NULL, MCTP_PHYS_BINDING_USB);
+ if (rc)
+ goto err_free_urbs;
+
+ return 0;
+
+err_free_urbs:
+ usb_free_urb(dev->tx_urb);
+ usb_free_urb(dev->rx_urb);
+ free_netdev(netdev);
+ return rc;
+}
+
+static void mctp_usb_disconnect(struct usb_interface *intf)
+{
+ struct mctp_usb *dev = usb_get_intfdata(intf);
+
+ mctp_unregister_netdev(dev->netdev);
+ usb_free_urb(dev->tx_urb);
+ usb_free_urb(dev->rx_urb);
+ usb_put_dev(dev->usbdev);
+ free_netdev(dev->netdev);
+}
+
+static const struct usb_device_id mctp_usb_devices[] = {
+ { USB_INTERFACE_INFO(USB_CLASS_MCTP, 0x0, 0x1) },
+ { 0 },
+};
+
+MODULE_DEVICE_TABLE(usb, mctp_usb_devices);
+
+static struct usb_driver mctp_usb_driver = {
+ .name = "mctp-usb",
+ .id_table = mctp_usb_devices,
+ .probe = mctp_usb_probe,
+ .disconnect = mctp_usb_disconnect,
+};
+
+module_usb_driver(mctp_usb_driver)
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jeremy Kerr <jk@codeconstruct.com.au>");
+MODULE_DESCRIPTION("MCTP USB transport");
generated by cgit (git 2.34.1) at 2025-12-25 03:56:23 +0000