diff options
Diffstat (limited to 'drivers/net/mctp')
| -rw-r--r-- | drivers/net/mctp/Kconfig | 12 | ||||
| -rw-r--r-- | drivers/net/mctp/Makefile | 1 | ||||
| -rw-r--r-- | drivers/net/mctp/mctp-i2c.c | 982 |
3 files changed, 0 insertions, 995 deletions
diff --git a/drivers/net/mctp/Kconfig b/drivers/net/mctp/Kconfig index b758b29c2ddf..d8f966cedc89 100644 --- a/drivers/net/mctp/Kconfig +++ b/drivers/net/mctp/Kconfig @@ -3,18 +3,6 @@ if MCTP menu "MCTP Device Drivers" -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 - depends on I2C_MUX || !I2C_MUX - depends on I2C - depends on I2C_SLAVE - select MCTP_FLOWS - help - Provides a driver to access MCTP devices over SMBus/I2C transport, - from DMTF specification DSP0237. A MCTP protocol network device is - created for each I2C bus that has been assigned a mctp-i2c device. - endmenu endif diff --git a/drivers/net/mctp/Makefile b/drivers/net/mctp/Makefile index 73dc411986a6..e69de29bb2d1 100644 --- a/drivers/net/mctp/Makefile +++ b/drivers/net/mctp/Makefile @@ -1 +0,0 @@ -obj-$(CONFIG_MCTP_TRANSPORT_I2C) += mctp-i2c.o diff --git a/drivers/net/mctp/mctp-i2c.c b/drivers/net/mctp/mctp-i2c.c deleted file mode 100644 index ed213b4765a1..000000000000 --- a/drivers/net/mctp/mctp-i2c.c +++ /dev/null @@ -1,982 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * Management Controller Transport Protocol (MCTP) - * - * Copyright (c) 2021 Code Construct - * Copyright (c) 2021 Google - */ - -#include <linux/module.h> -#include <linux/netdevice.h> -#include <linux/i2c.h> -#include <linux/i2c-mux.h> -#include <linux/if_arp.h> -#include <net/mctp.h> -#include <net/mctpdevice.h> - -/* SMBus 3.0 allows 255 data bytes (plus PEC), but the - * first byte is taken for source slave address. - */ -#define MCTP_I2C_MAXBLOCK 255 -#define MCTP_I2C_MAXMTU (MCTP_I2C_MAXBLOCK - 1) -#define MCTP_I2C_MINMTU (64 + 4) -/* Allow space for address, command, byte_count, databytes, PEC */ -#define MCTP_I2C_RXBUFSZ (3 + MCTP_I2C_MAXBLOCK + 1) -#define MCTP_I2C_MINLEN 8 -#define MCTP_I2C_COMMANDCODE 0x0f -#define MCTP_I2C_TX_WORK_LEN 100 -// sufficient for 64kB at min mtu -#define MCTP_I2C_TX_QUEUE_LEN 1100 - -#define MCTP_I2C_OF_PROP "mctp-controller" - -enum { - MCTP_I2C_FLOW_STATE_NEW = 0, - MCTP_I2C_FLOW_STATE_ACTIVE, -}; - -static struct { - /* lock protects clients and also prevents adding/removing adapters - * during mctp_i2c_client probe/remove. - */ - struct mutex lock; - // list of struct mctp_i2c_client - struct list_head clients; -} mi_driver_state; - -struct mctp_i2c_client; - -// The netdev structure. One of these per I2C adapter. -struct mctp_i2c_dev { - struct net_device *ndev; - struct i2c_adapter *adapter; - struct mctp_i2c_client *client; - struct list_head list; // for mctp_i2c_client.devs - - size_t pos; - u8 buffer[MCTP_I2C_RXBUFSZ]; - - struct task_struct *tx_thread; - wait_queue_head_t tx_wq; - struct sk_buff_head tx_queue; - - // a fake entry in our tx queue to perform an unlock operation - struct sk_buff unlock_marker; - - spinlock_t flow_lock; // protects i2c_lock_count and release_count - int i2c_lock_count; - int release_count; -}; - -/* The i2c client structure. One per hardware i2c bus at the top of the - * mux tree, shared by multiple netdevs - */ -struct mctp_i2c_client { - struct i2c_client *client; - u8 lladdr; - - struct mctp_i2c_dev *sel; - struct list_head devs; - spinlock_t curr_lock; // protects sel - - struct list_head list; // for mi_driver_state.clients -}; - -// Header on the wire -struct mctp_i2c_hdr { - u8 dest_slave; - u8 command; - u8 byte_count; - u8 source_slave; -}; - -static int mctp_i2c_recv(struct mctp_i2c_dev *midev); -static int mctp_i2c_slave_cb(struct i2c_client *client, - enum i2c_slave_event event, u8 *val); - -static struct i2c_adapter *mux_root_adapter(struct i2c_adapter *adap) -{ -#if IS_ENABLED(CONFIG_I2C_MUX) - return i2c_root_adapter(&adap->dev); -#else - /* In non-mux config all i2c adapters are root adapters */ - return adap; -#endif -} - -static ssize_t mctp_current_mux_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct mctp_i2c_client *mcli = i2c_get_clientdata(to_i2c_client(dev)); - struct net_device *ndev = NULL; - unsigned long flags; - ssize_t l; - - spin_lock_irqsave(&mcli->curr_lock, flags); - if (mcli->sel) { - ndev = mcli->sel->ndev; - dev_hold(ndev); - } - spin_unlock_irqrestore(&mcli->curr_lock, flags); - l = scnprintf(buf, PAGE_SIZE, "%s\n", ndev ? ndev->name : "(none)"); - if (ndev) - dev_put(ndev); - return l; -} -static DEVICE_ATTR_RO(mctp_current_mux); - -/* Creates a new i2c slave device attached to the root adapter. - * Sets up the slave callback. - * Must be called with a client on a root adapter. - */ -static struct mctp_i2c_client *mctp_i2c_new_client(struct i2c_client *client) -{ - struct mctp_i2c_client *mcli = NULL; - struct i2c_adapter *root = NULL; - int rc; - - if (client->flags & I2C_CLIENT_TEN) { - dev_err(&client->dev, "%s failed, MCTP requires a 7-bit I2C address, addr=0x%x", - __func__, client->addr); - rc = -EINVAL; - goto err; - } - - root = mux_root_adapter(client->adapter); - if (!root) { - dev_err(&client->dev, "%s failed to find root adapter\n", __func__); - rc = -ENOENT; - goto err; - } - if (root != client->adapter) { - dev_err(&client->dev, - "A mctp-i2c-controller client cannot be placed on an I2C mux adapter.\n" - " It should be placed on the mux tree root adapter\n" - " then set mctp-controller property on adapters to attach\n"); - rc = -EINVAL; - goto err; - } - - mcli = kzalloc(sizeof(*mcli), GFP_KERNEL); - if (!mcli) { - rc = -ENOMEM; - goto err; - } - spin_lock_init(&mcli->curr_lock); - INIT_LIST_HEAD(&mcli->devs); - INIT_LIST_HEAD(&mcli->list); - mcli->lladdr = client->addr & 0xff; - mcli->client = client; - i2c_set_clientdata(client, mcli); - - rc = i2c_slave_register(mcli->client, mctp_i2c_slave_cb); - if (rc) { - dev_err(&client->dev, "%s i2c register failed %d\n", __func__, rc); - mcli->client = NULL; - i2c_set_clientdata(client, NULL); - goto err; - } - - rc = device_create_file(&client->dev, &dev_attr_mctp_current_mux); - if (rc) { - dev_err(&client->dev, "%s adding sysfs \"%s\" failed %d\n", __func__, - dev_attr_mctp_current_mux.attr.name, rc); - // continue anyway - } - - return mcli; -err: - if (mcli) { - if (mcli->client) { - device_remove_file(&mcli->client->dev, &dev_attr_mctp_current_mux); - i2c_unregister_device(mcli->client); - } - kfree(mcli); - } - return ERR_PTR(rc); -} - -static void mctp_i2c_free_client(struct mctp_i2c_client *mcli) -{ - int rc; - - WARN_ON(!mutex_is_locked(&mi_driver_state.lock)); - WARN_ON(!list_empty(&mcli->devs)); - WARN_ON(mcli->sel); // sanity check, no locking - - device_remove_file(&mcli->client->dev, &dev_attr_mctp_current_mux); - rc = i2c_slave_unregister(mcli->client); - // leak if it fails, we can't propagate errors upwards - if (rc) - dev_err(&mcli->client->dev, "%s i2c unregister failed %d\n", __func__, rc); - else - kfree(mcli); -} - -/* Switch the mctp i2c device to receive responses. - * Call with curr_lock held - */ -static void __mctp_i2c_device_select(struct mctp_i2c_client *mcli, - struct mctp_i2c_dev *midev) -{ - assert_spin_locked(&mcli->curr_lock); - if (midev) - dev_hold(midev->ndev); - if (mcli->sel) - dev_put(mcli->sel->ndev); - mcli->sel = midev; -} - -// Switch the mctp i2c device to receive responses -static void mctp_i2c_device_select(struct mctp_i2c_client *mcli, - struct mctp_i2c_dev *midev) -{ - unsigned long flags; - - spin_lock_irqsave(&mcli->curr_lock, flags); - __mctp_i2c_device_select(mcli, midev); - spin_unlock_irqrestore(&mcli->curr_lock, flags); -} - -static int mctp_i2c_slave_cb(struct i2c_client *client, - enum i2c_slave_event event, u8 *val) -{ - struct mctp_i2c_client *mcli = i2c_get_clientdata(client); - struct mctp_i2c_dev *midev = NULL; - unsigned long flags; - int rc = 0; - - spin_lock_irqsave(&mcli->curr_lock, flags); - midev = mcli->sel; - if (midev) - dev_hold(midev->ndev); - spin_unlock_irqrestore(&mcli->curr_lock, flags); - - if (!midev) - return 0; - - switch (event) { - case I2C_SLAVE_WRITE_RECEIVED: - if (midev->pos < MCTP_I2C_RXBUFSZ) { - midev->buffer[midev->pos] = *val; - midev->pos++; - } else { - midev->ndev->stats.rx_over_errors++; - } - - break; - case I2C_SLAVE_WRITE_REQUESTED: - /* dest_slave as first byte */ - midev->buffer[0] = mcli->lladdr << 1; - midev->pos = 1; - break; - case I2C_SLAVE_STOP: - rc = mctp_i2c_recv(midev); - break; - default: - break; - } - - dev_put(midev->ndev); - return rc; -} - -// Processes incoming data that has been accumulated by the slave cb -static int mctp_i2c_recv(struct mctp_i2c_dev *midev) -{ - struct net_device *ndev = midev->ndev; - struct mctp_i2c_hdr *hdr; - struct mctp_skb_cb *cb; - struct sk_buff *skb; - u8 pec, calc_pec; - size_t recvlen; - - /* + 1 for the PEC */ - if (midev->pos < MCTP_I2C_MINLEN + 1) { - ndev->stats.rx_length_errors++; - return -EINVAL; - } - recvlen = midev->pos - 1; - - hdr = (void *)midev->buffer; - if (hdr->command != MCTP_I2C_COMMANDCODE) { - ndev->stats.rx_dropped++; - return -EINVAL; - } - - pec = midev->buffer[midev->pos - 1]; - calc_pec = i2c_smbus_pec(0, midev->buffer, recvlen); - if (pec != calc_pec) { - ndev->stats.rx_crc_errors++; - return -EINVAL; - } - - skb = netdev_alloc_skb(ndev, recvlen); - if (!skb) { - ndev->stats.rx_dropped++; - return -ENOMEM; - } - - skb->protocol = htons(ETH_P_MCTP); - skb_put_data(skb, midev->buffer, recvlen); - skb_reset_mac_header(skb); - skb_pull(skb, sizeof(struct mctp_i2c_hdr)); - skb_reset_network_header(skb); - - cb = __mctp_cb(skb); - cb->halen = 1; - cb->haddr[0] = hdr->source_slave; - - if (netif_rx(skb) == NET_RX_SUCCESS) { - ndev->stats.rx_packets++; - ndev->stats.rx_bytes += skb->len; - } else { - ndev->stats.rx_dropped++; - } - return 0; -} - -enum mctp_i2c_flow_state { - MCTP_I2C_TX_FLOW_INVALID, - MCTP_I2C_TX_FLOW_NONE, - MCTP_I2C_TX_FLOW_NEW, - MCTP_I2C_TX_FLOW_EXISTING, -}; - -static enum mctp_i2c_flow_state -mctp_i2c_get_tx_flow_state(struct mctp_i2c_dev *midev, struct sk_buff *skb) -{ - enum mctp_i2c_flow_state state; - struct mctp_sk_key *key; - struct mctp_flow *flow; - unsigned long flags; - - flow = skb_ext_find(skb, SKB_EXT_MCTP); - if (!flow) - return MCTP_I2C_TX_FLOW_NONE; - - key = flow->key; - if (!key) - return MCTP_I2C_TX_FLOW_NONE; - - spin_lock_irqsave(&key->lock, flags); - /* if the key is present but invalid, we're unlikely to be able - * to handle the flow at all; just drop now - */ - if (!key->valid) { - state = MCTP_I2C_TX_FLOW_INVALID; - - } else if (key->dev_flow_state == MCTP_I2C_FLOW_STATE_NEW) { - key->dev_flow_state = MCTP_I2C_FLOW_STATE_ACTIVE; - state = MCTP_I2C_TX_FLOW_NEW; - } else { - state = MCTP_I2C_TX_FLOW_EXISTING; - } - - spin_unlock_irqrestore(&key->lock, flags); - - return state; -} - -/* We're not contending with ourselves here; we only need to exclude other - * i2c clients from using the bus. refcounts are simply to prevent - * recursive locking. - */ -static void mctp_i2c_lock_nest(struct mctp_i2c_dev *midev) -{ - unsigned long flags; - bool lock; - - spin_lock_irqsave(&midev->flow_lock, flags); - lock = midev->i2c_lock_count == 0; - midev->i2c_lock_count++; - spin_unlock_irqrestore(&midev->flow_lock, flags); - - if (lock) - i2c_lock_bus(midev->adapter, I2C_LOCK_SEGMENT); -} - -static void mctp_i2c_unlock_nest(struct mctp_i2c_dev *midev) -{ - unsigned long flags; - bool unlock; - - spin_lock_irqsave(&midev->flow_lock, flags); - if (!WARN_ONCE(midev->i2c_lock_count == 0, "lock count underflow!")) - midev->i2c_lock_count--; - unlock = midev->i2c_lock_count == 0; - spin_unlock_irqrestore(&midev->flow_lock, flags); - - if (unlock) - i2c_unlock_bus(midev->adapter, I2C_LOCK_SEGMENT); -} - -static void mctp_i2c_xmit(struct mctp_i2c_dev *midev, struct sk_buff *skb) -{ - struct net_device_stats *stats = &midev->ndev->stats; - enum mctp_i2c_flow_state fs; - union i2c_smbus_data *data; - struct mctp_i2c_hdr *hdr; - unsigned int len; - u16 daddr; - int rc; - - fs = mctp_i2c_get_tx_flow_state(midev, skb); - - len = skb->len; - hdr = (void *)skb_mac_header(skb); - data = (void *)&hdr->byte_count; - daddr = hdr->dest_slave >> 1; - - switch (fs) { - case MCTP_I2C_TX_FLOW_NONE: - /* no flow: full lock & unlock */ - mctp_i2c_lock_nest(midev); - mctp_i2c_device_select(midev->client, midev); - rc = __i2c_smbus_xfer(midev->adapter, daddr, I2C_CLIENT_PEC, - I2C_SMBUS_WRITE, hdr->command, - I2C_SMBUS_BLOCK_DATA, data); - mctp_i2c_unlock_nest(midev); - break; - - case MCTP_I2C_TX_FLOW_NEW: - /* new flow: lock, tx, but don't unlock; that will happen - * on flow release - */ - mctp_i2c_lock_nest(midev); - mctp_i2c_device_select(midev->client, midev); - fallthrough; - - case MCTP_I2C_TX_FLOW_EXISTING: - /* existing flow: we already have the lock; just tx */ - rc = __i2c_smbus_xfer(midev->adapter, daddr, I2C_CLIENT_PEC, - I2C_SMBUS_WRITE, hdr->command, - I2C_SMBUS_BLOCK_DATA, data); - break; - - case MCTP_I2C_TX_FLOW_INVALID: - return; - } - - if (rc) { - dev_warn_ratelimited(&midev->adapter->dev, - "%s i2c_smbus_xfer failed %d", __func__, rc); - stats->tx_errors++; - } else { - stats->tx_bytes += len; - stats->tx_packets++; - } -} - -static void mctp_i2c_flow_release(struct mctp_i2c_dev *midev) -{ - unsigned long flags; - bool unlock; - - spin_lock_irqsave(&midev->flow_lock, flags); - if (midev->release_count > midev->i2c_lock_count) { - WARN_ONCE(1, "release count overflow"); - midev->release_count = midev->i2c_lock_count; - } - - midev->i2c_lock_count -= midev->release_count; - unlock = midev->i2c_lock_count == 0 && midev->release_count > 0; - midev->release_count = 0; - spin_unlock_irqrestore(&midev->flow_lock, flags); - - if (unlock) - i2c_unlock_bus(midev->adapter, I2C_LOCK_SEGMENT); -} - -static int mctp_i2c_header_create(struct sk_buff *skb, struct net_device *dev, - unsigned short type, const void *daddr, - const void *saddr, unsigned int len) -{ - struct mctp_i2c_hdr *hdr; - struct mctp_hdr *mhdr; - u8 lldst, llsrc; - - lldst = *((u8 *)daddr); - llsrc = *((u8 *)saddr); - - skb_push(skb, sizeof(struct mctp_i2c_hdr)); - skb_reset_mac_header(skb); - hdr = (void *)skb_mac_header(skb); - mhdr = mctp_hdr(skb); - hdr->dest_slave = (lldst << 1) & 0xff; - hdr->command = MCTP_I2C_COMMANDCODE; - hdr->byte_count = len + 1; - if (hdr->byte_count > MCTP_I2C_MAXBLOCK) - return -EMSGSIZE; - hdr->source_slave = ((llsrc << 1) & 0xff) | 0x01; - mhdr->ver = 0x01; - - return 0; -} - -static int mctp_i2c_tx_thread(void *data) -{ - struct mctp_i2c_dev *midev = data; - struct sk_buff *skb; - unsigned long flags; - - for (;;) { - if (kthread_should_stop()) - break; - - spin_lock_irqsave(&midev->tx_queue.lock, flags); - skb = __skb_dequeue(&midev->tx_queue); - if (netif_queue_stopped(midev->ndev)) - netif_wake_queue(midev->ndev); - spin_unlock_irqrestore(&midev->tx_queue.lock, flags); - - if (skb == &midev->unlock_marker) { - mctp_i2c_flow_release(midev); - - } else if (skb) { - mctp_i2c_xmit(midev, skb); - kfree_skb(skb); - - } else { - wait_event(midev->tx_wq, - !skb_queue_empty(&midev->tx_queue) || - kthread_should_stop()); - } - } - - return 0; -} - -static netdev_tx_t mctp_i2c_start_xmit(struct sk_buff *skb, - struct net_device *dev) -{ - struct mctp_i2c_dev *midev = netdev_priv(dev); - unsigned long flags; - - spin_lock_irqsave(&midev->tx_queue.lock, flags); - if (skb_queue_len(&midev->tx_queue) >= MCTP_I2C_TX_WORK_LEN) { - netif_stop_queue(dev); - spin_unlock_irqrestore(&midev->tx_queue.lock, flags); - netdev_err(dev, "BUG! Tx Ring full when queue awake!\n"); - return NETDEV_TX_BUSY; - } - - __skb_queue_tail(&midev->tx_queue, skb); - if (skb_queue_len(&midev->tx_queue) == MCTP_I2C_TX_WORK_LEN) - netif_stop_queue(dev); - spin_unlock_irqrestore(&midev->tx_queue.lock, flags); - - wake_up(&midev->tx_wq); - return NETDEV_TX_OK; -} - -static void mctp_i2c_release_flow(struct mctp_dev *mdev, - struct mctp_sk_key *key) - -{ - struct mctp_i2c_dev *midev = netdev_priv(mdev->dev); - unsigned long flags; - - spin_lock_irqsave(&midev->flow_lock, flags); - midev->release_count++; - spin_unlock_irqrestore(&midev->flow_lock, flags); - - /* Ensure we have a release operation queued, through the fake - * marker skb - */ - spin_lock(&midev->tx_queue.lock); - if (!midev->unlock_marker.next) - __skb_queue_tail(&midev->tx_queue, &midev->unlock_marker); - spin_unlock(&midev->tx_queue.lock); - - wake_up(&midev->tx_wq); -} - -static const struct net_device_ops mctp_i2c_ops = { - .ndo_start_xmit = mctp_i2c_start_xmit, -}; - -static const struct header_ops mctp_i2c_headops = { - .create = mctp_i2c_header_create, -}; - -static const struct mctp_netdev_ops mctp_i2c_mctp_ops = { - .release_flow = mctp_i2c_release_flow, -}; - -static void mctp_i2c_net_setup(struct net_device *dev) -{ - dev->type = ARPHRD_MCTP; - - dev->mtu = MCTP_I2C_MAXMTU; - dev->min_mtu = MCTP_I2C_MINMTU; - dev->max_mtu = MCTP_I2C_MAXMTU; - dev->tx_queue_len = MCTP_I2C_TX_QUEUE_LEN; - - dev->hard_header_len = sizeof(struct mctp_i2c_hdr); - dev->addr_len = 1; - - dev->netdev_ops = &mctp_i2c_ops; - dev->header_ops = &mctp_i2c_headops; - dev->needs_free_netdev = true; -} - -static int mctp_i2c_add_netdev(struct mctp_i2c_client *mcli, - struct i2c_adapter *adap) -{ - unsigned long flags; - struct mctp_i2c_dev *midev = NULL; - struct net_device *ndev = NULL; - struct i2c_adapter *root; - char namebuf[30]; - int rc; - - root = mux_root_adapter(adap); - if (root != mcli->client->adapter) { - dev_err(&mcli->client->dev, - "I2C adapter %s is not a child bus of %s", - mcli->client->adapter->name, root->name); - return -EINVAL; - } - - WARN_ON(!mutex_is_locked(&mi_driver_state.lock)); - snprintf(namebuf, sizeof(namebuf), "mctpi2c%d", adap->nr); - ndev = alloc_netdev(sizeof(*midev), namebuf, NET_NAME_ENUM, mctp_i2c_net_setup); - if (!ndev) { - dev_err(&mcli->client->dev, "%s alloc netdev failed\n", __func__); - rc = -ENOMEM; - goto err; - } - dev_net_set(ndev, current->nsproxy->net_ns); - SET_NETDEV_DEV(ndev, &adap->dev); - ndev->dev_addr = &mcli->lladdr; - - midev = netdev_priv(ndev); - skb_queue_head_init(&midev->tx_queue); - INIT_LIST_HEAD(&midev->list); - midev->adapter = adap; - midev->client = mcli; - spin_lock_init(&midev->flow_lock); - midev->i2c_lock_count = 0; - midev->release_count = 0; - /* Hold references */ - get_device(&midev->adapter->dev); - get_device(&midev->client->client->dev); - midev->ndev = ndev; - init_waitqueue_head(&midev->tx_wq); - midev->tx_thread = kthread_create(mctp_i2c_tx_thread, midev, - "%s/tx", namebuf); - if (IS_ERR_OR_NULL(midev->tx_thread)) { - rc = -ENOMEM; - goto err_free; - } - - rc = mctp_register_netdev(ndev, &mctp_i2c_mctp_ops); - if (rc) { - dev_err(&mcli->client->dev, - "%s register netdev \"%s\" failed %d\n", __func__, - ndev->name, rc); - goto err_stop_kthread; - } - spin_lock_irqsave(&mcli->curr_lock, flags); - list_add(&midev->list, &mcli->devs); - // Select a device by default - if (!mcli->sel) - __mctp_i2c_device_select(mcli, midev); - spin_unlock_irqrestore(&mcli->curr_lock, flags); - - wake_up_process(midev->tx_thread); - - return 0; - -err_stop_kthread: - kthread_stop(midev->tx_thread); - -err_free: - free_netdev(ndev); - -err: - return rc; -} - -// Removes and unregisters a mctp-i2c netdev -static void mctp_i2c_free_netdev(struct mctp_i2c_dev *midev) -{ - struct mctp_i2c_client *mcli = midev->client; - unsigned long flags; - - netif_stop_queue(midev->ndev); - kthread_stop(midev->tx_thread); - skb_queue_purge(&midev->tx_queue); - - /* Release references, used only for TX which has stopped */ - put_device(&midev->adapter->dev); - put_device(&mcli->client->dev); - - /* Remove it from the parent mcli */ - spin_lock_irqsave(&mcli->curr_lock, flags); - list_del(&midev->list); - if (mcli->sel == midev) { - struct mctp_i2c_dev *first; - - first = list_first_entry_or_null(&mcli->devs, struct mctp_i2c_dev, list); - __mctp_i2c_device_select(mcli, first); - } - spin_unlock_irqrestore(&mcli->curr_lock, flags); - - /* Remove netdev. mctp_i2c_slave_cb() takes a dev_hold() so removing - * it now is safe. unregister_netdev() frees ndev and midev. - */ - mctp_unregister_netdev(midev->ndev); -} - -// Removes any netdev for adap. mcli is the parent root i2c client -static void mctp_i2c_remove_netdev(struct mctp_i2c_client *mcli, - struct i2c_adapter *adap) -{ - unsigned long flags; - struct mctp_i2c_dev *midev = NULL, *m = NULL; - - WARN_ON(!mutex_is_locked(&mi_driver_state.lock)); - spin_lock_irqsave(&mcli->curr_lock, flags); - // list size is limited by number of MCTP netdevs on a single hardware bus - list_for_each_entry(m, &mcli->devs, list) - if (m->adapter == adap) { - midev = m; - break; - } - spin_unlock_irqrestore(&mcli->curr_lock, flags); - - if (midev) - mctp_i2c_free_netdev(midev); -} - -/* Determines whether a device is an i2c adapter. - * Optionally returns the root i2c_adapter - */ -static struct i2c_adapter *mctp_i2c_get_adapter(struct device *dev, - struct i2c_adapter **ret_root) -{ - struct i2c_adapter *root, *adap; - - if (dev->type != &i2c_adapter_type) - return NULL; - adap = to_i2c_adapter(dev); - root = mux_root_adapter(adap); - WARN_ONCE(!root, "%s failed to find root adapter for %s\n", - __func__, dev_name(dev)); - if (!root) - return NULL; - if (ret_root) - *ret_root = root; - return adap; -} - -/* Determines whether a device is an i2c adapter with the "mctp-controller" - * devicetree property set. If adap is not an OF node, returns match_no_of - */ -static bool mctp_i2c_adapter_match(struct i2c_adapter *adap, bool match_no_of) -{ - if (!adap->dev.of_node) - return match_no_of; - return of_property_read_bool(adap->dev.of_node, MCTP_I2C_OF_PROP); -} - -/* Called for each existing i2c device (adapter or client) when a - * new mctp-i2c client is probed. - */ -static int mctp_i2c_client_try_attach(struct device *dev, void *data) -{ - struct i2c_adapter *adap = NULL, *root = NULL; - struct mctp_i2c_client *mcli = data; - - adap = mctp_i2c_get_adapter(dev, &root); - if (!adap) - return 0; - if (mcli->client->adapter != root) - return 0; - // Must either have mctp-controller property on the adapter, or - // be a root adapter if it's non-devicetree - if (!mctp_i2c_adapter_match(adap, adap == root)) - return 0; - - return mctp_i2c_add_netdev(mcli, adap); -} - -static void mctp_i2c_notify_add(struct device *dev) -{ - struct mctp_i2c_client *mcli = NULL, *m = NULL; - struct i2c_adapter *root = NULL, *adap = NULL; - int rc; - - adap = mctp_i2c_get_adapter(dev, &root); - if (!adap) - return; - // Check for mctp-controller property on the adapter - if (!mctp_i2c_adapter_match(adap, false)) - return; - - /* Find an existing mcli for adap's root */ - mutex_lock(&mi_driver_state.lock); - list_for_each_entry(m, &mi_driver_state.clients, list) { - if (m->client->adapter == root) { - mcli = m; - break; - } - } - - if (mcli) { - rc = mctp_i2c_add_netdev(mcli, adap); - if (rc) - dev_warn(dev, "%s Failed adding mctp-i2c device", - __func__); - } - mutex_unlock(&mi_driver_state.lock); -} - -static void mctp_i2c_notify_del(struct device *dev) -{ - struct i2c_adapter *root = NULL, *adap = NULL; - struct mctp_i2c_client *mcli = NULL; - - adap = mctp_i2c_get_adapter(dev, &root); - if (!adap) - return; - - mutex_lock(&mi_driver_state.lock); - list_for_each_entry(mcli, &mi_driver_state.clients, list) { - if (mcli->client->adapter == root) { - mctp_i2c_remove_netdev(mcli, adap); - break; - } - } - mutex_unlock(&mi_driver_state.lock); -} - -static int mctp_i2c_probe(struct i2c_client *client) -{ - struct mctp_i2c_client *mcli = NULL; - int rc; - - /* Check for >32 byte block support required for MCTP */ - if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_V3_BLOCK)) { - dev_err(&client->dev, - "%s failed, I2C bus driver does not support 255 byte block transfer\n", - __func__); - return -EOPNOTSUPP; - } - - mutex_lock(&mi_driver_state.lock); - mcli = mctp_i2c_new_client(client); - if (IS_ERR(mcli)) { - rc = PTR_ERR(mcli); - mcli = NULL; - goto out; - } else { - list_add(&mcli->list, &mi_driver_state.clients); - } - - // Add a netdev for adapters that have a 'mctp-controller' property - i2c_for_each_dev(mcli, mctp_i2c_client_try_attach); - rc = 0; -out: - mutex_unlock(&mi_driver_state.lock); - return rc; -} - -static int mctp_i2c_remove(struct i2c_client *client) -{ - struct mctp_i2c_client *mcli = i2c_get_clientdata(client); - struct mctp_i2c_dev *midev = NULL, *tmp = NULL; - - mutex_lock(&mi_driver_state.lock); - list_del(&mcli->list); - // Remove all child adapter netdevs - list_for_each_entry_safe(midev, tmp, &mcli->devs, list) - mctp_i2c_free_netdev(midev); - - mctp_i2c_free_client(mcli); - mutex_unlock(&mi_driver_state.lock); - // Callers ignore return code - return 0; -} - -/* We look for a 'mctp-controller' property on I2C busses as they are - * added/deleted, creating/removing netdevs as required. - */ -static int mctp_i2c_notifier_call(struct notifier_block *nb, - unsigned long action, void *data) -{ - struct device *dev = data; - - switch (action) { - case BUS_NOTIFY_ADD_DEVICE: - mctp_i2c_notify_add(dev); - break; - case BUS_NOTIFY_DEL_DEVICE: - mctp_i2c_notify_del(dev); - break; - } - return NOTIFY_DONE; -} - -static struct notifier_block mctp_i2c_notifier = { - .notifier_call = mctp_i2c_notifier_call, -}; - -static const struct i2c_device_id mctp_i2c_id[] = { - { "mctp-i2c", 0 }, - {}, -}; -MODULE_DEVICE_TABLE(i2c, mctp_i2c_id); - -static const struct of_device_id mctp_i2c_of_match[] = { - { .compatible = "mctp-i2c-controller" }, - {}, -}; -MODULE_DEVICE_TABLE(of, mctp_i2c_of_match); - -static struct i2c_driver mctp_i2c_driver = { - .driver = { - .name = "mctp-i2c", - .of_match_table = mctp_i2c_of_match, - }, - .probe_new = mctp_i2c_probe, - .remove = mctp_i2c_remove, - .id_table = mctp_i2c_id, -}; - -static __init int mctp_i2c_init(void) -{ - int rc; - - INIT_LIST_HEAD(&mi_driver_state.clients); - mutex_init(&mi_driver_state.lock); - pr_info("MCTP SMBus/I2C transport driver\n"); - rc = i2c_add_driver(&mctp_i2c_driver); - if (rc) - return rc; - rc = bus_register_notifier(&i2c_bus_type, &mctp_i2c_notifier); - if (rc) { - i2c_del_driver(&mctp_i2c_driver); - return rc; - } - return 0; -} - -static __exit void mctp_i2c_exit(void) -{ - int rc; - - rc = bus_unregister_notifier(&i2c_bus_type, &mctp_i2c_notifier); - if (rc) - pr_warn("%s Could not unregister notifier, %d", __func__, rc); - i2c_del_driver(&mctp_i2c_driver); -} - -module_init(mctp_i2c_init); -module_exit(mctp_i2c_exit); - -MODULE_DESCRIPTION("MCTP SMBus/I2C device"); -MODULE_LICENSE("GPL v2"); -MODULE_AUTHOR("Matt Johnston <matt@codeconstruct.com.au>"); |