diff options
author | David Fries <David@Fries.net> | 2014-01-16 08:29:18 +0400 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-02-08 03:40:17 +0400 |
commit | 9fcbbac5ded489c3a4e121343db999dd51cd6c75 (patch) | |
tree | 1207602c8d7cc2da54784114a5d32d9ed6924b58 /drivers/w1/w1_netlink.c | |
parent | 70b34d2ed807b722413894975a8c60617defb887 (diff) |
w1: process w1 netlink commands in w1_process thread
Netlink is a socket interface and is expected to be asynchronous.
Clients can now make w1 requests without blocking by making use of the
w1_master thread to process netlink commands which was previously only
used for doing an automatic bus search.
Signed-off-by: David Fries <David@Fries.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/w1/w1_netlink.c')
-rw-r--r-- | drivers/w1/w1_netlink.c | 166 |
1 files changed, 129 insertions, 37 deletions
diff --git a/drivers/w1/w1_netlink.c b/drivers/w1/w1_netlink.c index 747174be7b50..06d614af1166 100644 --- a/drivers/w1/w1_netlink.c +++ b/drivers/w1/w1_netlink.c @@ -119,10 +119,12 @@ static int w1_get_slaves(struct w1_master *dev, if (req_cmd->cmd == W1_CMD_LIST_SLAVES) { __u64 rn; + mutex_lock(&dev->list_mutex); list_for_each_entry(sl, &dev->slist, w1_slave_entry) { memcpy(&rn, &sl->reg_num, sizeof(rn)); w1_send_slave(dev, rn); } + mutex_unlock(&dev->list_mutex); } else { w1_search_process_cb(dev, cmd->cmd == W1_CMD_ALARM_SEARCH ? W1_ALARM_SEARCH : W1_SEARCH, w1_found_send_slave); @@ -368,29 +370,134 @@ static int w1_netlink_send_error(struct cn_msg *rcmsg, struct w1_netlink_msg *rm return error; } +/* Bundle together a reference count, the full message, and broken out + * commands to be executed on each w1 master kthread in one memory allocation. + */ +struct w1_cb_block { + atomic_t refcnt; + struct cn_msg msg; + /* cn_msg data */ + /* one or more variable length struct w1_cb_node */ +}; +struct w1_cb_node { + struct w1_async_cmd async; + /* pointers within w1_cb_block and msg data */ + struct w1_cb_block *block; + struct w1_netlink_msg *m; + struct w1_slave *sl; + struct w1_master *dev; +}; + +static void w1_process_cb(struct w1_master *dev, struct w1_async_cmd *async_cmd) +{ + struct w1_cb_node *node = container_of(async_cmd, struct w1_cb_node, + async); + u16 mlen = node->m->len; + u8 *cmd_data = node->m->data; + int err = 0; + struct w1_slave *sl = node->sl; + struct w1_netlink_cmd *cmd = NULL; + + mutex_lock(&dev->mutex); + if (sl && w1_reset_select_slave(sl)) + err = -ENODEV; + + while (mlen && !err) { + cmd = (struct w1_netlink_cmd *)cmd_data; + + if (cmd->len + sizeof(struct w1_netlink_cmd) > mlen) { + err = -E2BIG; + break; + } + + if (sl) + err = w1_process_command_slave(sl, &node->block->msg, + node->m, cmd); + else + err = w1_process_command_master(dev, &node->block->msg, + node->m, cmd); + + w1_netlink_send_error(&node->block->msg, node->m, cmd, err); + err = 0; + + cmd_data += cmd->len + sizeof(struct w1_netlink_cmd); + mlen -= cmd->len + sizeof(struct w1_netlink_cmd); + } + + if (!cmd || err) + w1_netlink_send_error(&node->block->msg, node->m, cmd, err); + + if (sl) + w1_unref_slave(sl); + else + atomic_dec(&dev->refcnt); + mutex_unlock(&dev->mutex); + + mutex_lock(&dev->list_mutex); + list_del(&async_cmd->async_entry); + mutex_unlock(&dev->list_mutex); + + if (atomic_sub_return(1, &node->block->refcnt) == 0) + kfree(node->block); +} + static void w1_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp) { struct w1_netlink_msg *m = (struct w1_netlink_msg *)(msg + 1); - struct w1_netlink_cmd *cmd; struct w1_slave *sl; struct w1_master *dev; + u16 msg_len; int err = 0; + struct w1_cb_block *block = NULL; + struct w1_cb_node *node = NULL; + int node_count = 0; + + /* Count the number of master or slave commands there are to allocate + * space for one cb_node each. + */ + msg_len = msg->len; + while (msg_len && !err) { + if (m->len + sizeof(struct w1_netlink_msg) > msg_len) { + err = -E2BIG; + break; + } + + if (m->type == W1_MASTER_CMD || m->type == W1_SLAVE_CMD) + ++node_count; + + msg_len -= sizeof(struct w1_netlink_msg) + m->len; + m = (struct w1_netlink_msg *)(((u8 *)m) + + sizeof(struct w1_netlink_msg) + m->len); + } + m = (struct w1_netlink_msg *)(msg + 1); + if (node_count) { + /* msg->len doesn't include itself */ + long size = sizeof(struct w1_cb_block) + msg->len + + node_count*sizeof(struct w1_cb_node); + block = kmalloc(size, GFP_KERNEL); + if (!block) { + w1_netlink_send_error(msg, m, NULL, -ENOMEM); + return; + } + atomic_set(&block->refcnt, 1); + memcpy(&block->msg, msg, sizeof(*msg) + msg->len); + node = (struct w1_cb_node *)((u8 *)block->msg.data + msg->len); + } - while (msg->len && !err) { + msg_len = msg->len; + while (msg_len && !err) { struct w1_reg_num id; u16 mlen = m->len; - u8 *cmd_data = m->data; dev = NULL; sl = NULL; - cmd = NULL; memcpy(&id, m->id.id, sizeof(id)); #if 0 printk("%s: %02x.%012llx.%02x: type=%02x, len=%u.\n", __func__, id.family, (unsigned long long)id.id, id.crc, m->type, m->len); #endif - if (m->len + sizeof(struct w1_netlink_msg) > msg->len) { + if (m->len + sizeof(struct w1_netlink_msg) > msg_len) { err = -E2BIG; break; } @@ -415,41 +522,24 @@ static void w1_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp) if (!mlen) goto out_cont; - mutex_lock(&dev->mutex); + atomic_inc(&block->refcnt); + node->async.cb = w1_process_cb; + node->block = block; + node->m = (struct w1_netlink_msg *)((u8 *)&block->msg + + (size_t)((u8 *)m - (u8 *)msg)); + node->sl = sl; + node->dev = dev; - if (sl && w1_reset_select_slave(sl)) { - err = -ENODEV; - goto out_up; - } - - while (mlen) { - cmd = (struct w1_netlink_cmd *)cmd_data; - - if (cmd->len + sizeof(struct w1_netlink_cmd) > mlen) { - err = -E2BIG; - break; - } - - if (sl) - err = w1_process_command_slave(sl, msg, m, cmd); - else - err = w1_process_command_master(dev, msg, m, cmd); + mutex_lock(&dev->list_mutex); + list_add_tail(&node->async.async_entry, &dev->async_list); + wake_up_process(dev->thread); + mutex_unlock(&dev->list_mutex); + ++node; - w1_netlink_send_error(msg, m, cmd, err); - err = 0; - - cmd_data += cmd->len + sizeof(struct w1_netlink_cmd); - mlen -= cmd->len + sizeof(struct w1_netlink_cmd); - } -out_up: - atomic_dec(&dev->refcnt); - if (sl) - atomic_dec(&sl->refcnt); - mutex_unlock(&dev->mutex); out_cont: - if (!cmd || err) - w1_netlink_send_error(msg, m, cmd, err); - msg->len -= sizeof(struct w1_netlink_msg) + m->len; + if (err) + w1_netlink_send_error(msg, m, NULL, err); + msg_len -= sizeof(struct w1_netlink_msg) + m->len; m = (struct w1_netlink_msg *)(((u8 *)m) + sizeof(struct w1_netlink_msg) + m->len); /* @@ -458,6 +548,8 @@ out_cont: if (err == -ENODEV) err = 0; } + if (block && atomic_sub_return(1, &block->refcnt) == 0) + kfree(block); } int w1_init_netlink(void) |