doc: SubmittingPatches: remove dead link, kerneltrap.org no longer works
[cascardo/linux.git] / drivers / w1 / w1_netlink.c
index 73705af..5234964 100644 (file)
@@ -45,7 +45,7 @@ void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg)
 
        memcpy(w, msg, sizeof(struct w1_netlink_msg));
 
-       cn_netlink_send(m, 0, GFP_KERNEL);
+       cn_netlink_send(m, dev->portid, 0, GFP_KERNEL);
 }
 
 static void w1_send_slave(struct w1_master *dev, u64 rn)
@@ -56,14 +56,11 @@ static void w1_send_slave(struct w1_master *dev, u64 rn)
        int avail;
        u64 *data;
 
-       /* update kernel slave list */
-       w1_slave_found(dev, rn);
-
        avail = dev->priv_size - cmd->len;
 
        if (avail < 8) {
                msg->ack++;
-               cn_netlink_send(msg, 0, GFP_KERNEL);
+               cn_netlink_send(msg, dev->portid, 0, GFP_KERNEL);
 
                msg->len = sizeof(struct w1_netlink_msg) +
                        sizeof(struct w1_netlink_cmd);
@@ -79,29 +76,73 @@ static void w1_send_slave(struct w1_master *dev, u64 rn)
        msg->len += 8;
 }
 
-static int w1_process_search_command(struct w1_master *dev, struct cn_msg *msg,
-               unsigned int avail)
+static void w1_found_send_slave(struct w1_master *dev, u64 rn)
 {
-       struct w1_netlink_msg *hdr = (struct w1_netlink_msg *)(msg + 1);
-       struct w1_netlink_cmd *cmd = (struct w1_netlink_cmd *)(hdr + 1);
-       int search_type = (cmd->cmd == W1_CMD_ALARM_SEARCH)?W1_ALARM_SEARCH:W1_SEARCH;
+       /* update kernel slave list */
+       w1_slave_found(dev, rn);
 
-       dev->priv = msg;
-       dev->priv_size = avail;
+       w1_send_slave(dev, rn);
+}
 
-       w1_search_process_cb(dev, search_type, w1_send_slave);
+/* Get the current slave list, or search (with or without alarm) */
+static int w1_get_slaves(struct w1_master *dev,
+               struct cn_msg *req_msg, struct w1_netlink_msg *req_hdr,
+               struct w1_netlink_cmd *req_cmd)
+{
+       struct cn_msg *msg;
+       struct w1_netlink_msg *hdr;
+       struct w1_netlink_cmd *cmd;
+       struct w1_slave *sl;
 
+       msg = kzalloc(PAGE_SIZE, GFP_KERNEL);
+       if (!msg)
+               return -ENOMEM;
+
+       msg->id = req_msg->id;
+       msg->seq = req_msg->seq;
        msg->ack = 0;
-       cn_netlink_send(msg, 0, GFP_KERNEL);
+       msg->len = sizeof(struct w1_netlink_msg) +
+               sizeof(struct w1_netlink_cmd);
+
+       hdr = (struct w1_netlink_msg *)(msg + 1);
+       cmd = (struct w1_netlink_cmd *)(hdr + 1);
+
+       hdr->type = W1_MASTER_CMD;
+       hdr->id = req_hdr->id;
+       hdr->len = sizeof(struct w1_netlink_cmd);
+
+       cmd->cmd = req_cmd->cmd;
+       cmd->len = 0;
+
+       dev->priv = msg;
+       dev->priv_size = PAGE_SIZE - msg->len - sizeof(struct cn_msg);
+
+       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);
+       }
+
+       msg->ack = 0;
+       cn_netlink_send(msg, dev->portid, 0, GFP_KERNEL);
 
        dev->priv = NULL;
        dev->priv_size = 0;
 
+       kfree(msg);
+
        return 0;
 }
 
 static int w1_send_read_reply(struct cn_msg *msg, struct w1_netlink_msg *hdr,
-               struct w1_netlink_cmd *cmd)
+               struct w1_netlink_cmd *cmd, u32 portid)
 {
        void *data;
        struct w1_netlink_msg *h;
@@ -132,7 +173,7 @@ static int w1_send_read_reply(struct cn_msg *msg, struct w1_netlink_msg *hdr,
 
        memcpy(c->data, cmd->data, c->len);
 
-       err = cn_netlink_send(cm, 0, GFP_KERNEL);
+       err = cn_netlink_send(cm, portid, 0, GFP_KERNEL);
 
        kfree(data);
 
@@ -147,11 +188,11 @@ static int w1_process_command_io(struct w1_master *dev, struct cn_msg *msg,
        switch (cmd->cmd) {
        case W1_CMD_TOUCH:
                w1_touch_block(dev, cmd->data, cmd->len);
-               w1_send_read_reply(msg, hdr, cmd);
+               w1_send_read_reply(msg, hdr, cmd, dev->portid);
                break;
        case W1_CMD_READ:
                w1_read_block(dev, cmd->data, cmd->len);
-               w1_send_read_reply(msg, hdr, cmd);
+               w1_send_read_reply(msg, hdr, cmd, dev->portid);
                break;
        case W1_CMD_WRITE:
                w1_write_block(dev, cmd->data, cmd->len);
@@ -164,38 +205,57 @@ static int w1_process_command_io(struct w1_master *dev, struct cn_msg *msg,
        return err;
 }
 
-static int w1_process_command_master(struct w1_master *dev, struct cn_msg *req_msg,
-               struct w1_netlink_msg *req_hdr, struct w1_netlink_cmd *req_cmd)
+static int w1_process_command_addremove(struct w1_master *dev,
+       struct cn_msg *msg, struct w1_netlink_msg *hdr,
+       struct w1_netlink_cmd *cmd)
 {
-       int err = -EINVAL;
-       struct cn_msg *msg;
-       struct w1_netlink_msg *hdr;
-       struct w1_netlink_cmd *cmd;
+       struct w1_slave *sl;
+       int err = 0;
+       struct w1_reg_num *id;
 
-       msg = kzalloc(PAGE_SIZE, GFP_KERNEL);
-       if (!msg)
-               return -ENOMEM;
+       if (cmd->len != 8)
+               return -EINVAL;
 
-       msg->id = req_msg->id;
-       msg->seq = req_msg->seq;
-       msg->ack = 0;
-       msg->len = sizeof(struct w1_netlink_msg) + sizeof(struct w1_netlink_cmd);
+       id = (struct w1_reg_num *)cmd->data;
 
-       hdr = (struct w1_netlink_msg *)(msg + 1);
-       cmd = (struct w1_netlink_cmd *)(hdr + 1);
+       sl = w1_slave_search_device(dev, id);
+       switch (cmd->cmd) {
+       case W1_CMD_SLAVE_ADD:
+               if (sl)
+                       err = -EINVAL;
+               else
+                       err = w1_attach_slave_device(dev, id);
+               break;
+       case W1_CMD_SLAVE_REMOVE:
+               if (sl)
+                       w1_slave_detach(sl);
+               else
+                       err = -EINVAL;
+               break;
+       default:
+               err = -EINVAL;
+               break;
+       }
 
-       hdr->type = W1_MASTER_CMD;
-       hdr->id = req_hdr->id;
-       hdr->len = sizeof(struct w1_netlink_cmd);
+       return err;
+}
 
-       cmd->cmd = req_cmd->cmd;
-       cmd->len = 0;
+static int w1_process_command_master(struct w1_master *dev,
+       struct cn_msg *req_msg, struct w1_netlink_msg *req_hdr,
+       struct w1_netlink_cmd *req_cmd)
+{
+       int err = -EINVAL;
 
-       switch (cmd->cmd) {
+       /* drop bus_mutex for search (does it's own locking), and add/remove
+        * which doesn't use the bus
+        */
+       switch (req_cmd->cmd) {
        case W1_CMD_SEARCH:
        case W1_CMD_ALARM_SEARCH:
-               err = w1_process_search_command(dev, msg,
-                               PAGE_SIZE - msg->len - sizeof(struct cn_msg));
+       case W1_CMD_LIST_SLAVES:
+               mutex_unlock(&dev->bus_mutex);
+               err = w1_get_slaves(dev, req_msg, req_hdr, req_cmd);
+               mutex_lock(&dev->bus_mutex);
                break;
        case W1_CMD_READ:
        case W1_CMD_WRITE:
@@ -205,12 +265,20 @@ static int w1_process_command_master(struct w1_master *dev, struct cn_msg *req_m
        case W1_CMD_RESET:
                err = w1_reset_bus(dev);
                break;
+       case W1_CMD_SLAVE_ADD:
+       case W1_CMD_SLAVE_REMOVE:
+               mutex_unlock(&dev->bus_mutex);
+               mutex_lock(&dev->mutex);
+               err = w1_process_command_addremove(dev, req_msg, req_hdr,
+                       req_cmd);
+               mutex_unlock(&dev->mutex);
+               mutex_lock(&dev->bus_mutex);
+               break;
        default:
                err = -EINVAL;
                break;
        }
 
-       kfree(msg);
        return err;
 }
 
@@ -224,7 +292,8 @@ static int w1_process_command_slave(struct w1_slave *sl, struct cn_msg *msg,
        return w1_process_command_io(sl->master, msg, hdr, cmd);
 }
 
-static int w1_process_command_root(struct cn_msg *msg, struct w1_netlink_msg *mcmd)
+static int w1_process_command_root(struct cn_msg *msg,
+       struct w1_netlink_msg *mcmd, u32 portid)
 {
        struct w1_master *m;
        struct cn_msg *cn;
@@ -257,7 +326,7 @@ static int w1_process_command_root(struct cn_msg *msg, struct w1_netlink_msg *mc
        mutex_lock(&w1_mlock);
        list_for_each_entry(m, &w1_masters, w1_master_entry) {
                if (cn->len + sizeof(*id) > PAGE_SIZE - sizeof(struct cn_msg)) {
-                       cn_netlink_send(cn, 0, GFP_KERNEL);
+                       cn_netlink_send(cn, portid, 0, GFP_KERNEL);
                        cn->ack++;
                        cn->len = sizeof(struct w1_netlink_msg);
                        w->len = 0;
@@ -270,7 +339,7 @@ static int w1_process_command_root(struct cn_msg *msg, struct w1_netlink_msg *mc
                id++;
        }
        cn->ack = 0;
-       cn_netlink_send(cn, 0, GFP_KERNEL);
+       cn_netlink_send(cn, portid, 0, GFP_KERNEL);
        mutex_unlock(&w1_mlock);
 
        kfree(cn);
@@ -278,7 +347,7 @@ static int w1_process_command_root(struct cn_msg *msg, struct w1_netlink_msg *mc
 }
 
 static int w1_netlink_send_error(struct cn_msg *rcmsg, struct w1_netlink_msg *rmsg,
-               struct w1_netlink_cmd *rcmd, int error)
+               struct w1_netlink_cmd *rcmd, int portid, int error)
 {
        struct cn_msg *cmsg;
        struct w1_netlink_msg *msg;
@@ -305,35 +374,147 @@ static int w1_netlink_send_error(struct cn_msg *rcmsg, struct w1_netlink_msg *rm
                cmsg->len += sizeof(*cmd);
        }
 
-       error = cn_netlink_send(cmsg, 0, GFP_KERNEL);
+       error = cn_netlink_send(cmsg, portid, 0, GFP_KERNEL);
        kfree(cmsg);
 
        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;
+       u32 portid; /* Sending process port ID */
+       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->bus_mutex);
+       dev->portid = node->block->portid;
+       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,
+                       node->block->portid, 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,
+                       node->block->portid, err);
+
+       if (sl)
+               w1_unref_slave(sl);
+       else
+               atomic_dec(&dev->refcnt);
+       dev->portid = 0;
+       mutex_unlock(&dev->bus_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, nsp->portid,
+                               -ENOMEM);
+                       return;
+               }
+               atomic_set(&block->refcnt, 1);
+               block->portid = nsp->portid;
+               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;
                }
@@ -345,7 +526,7 @@ static void w1_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
                        if (sl)
                                dev = sl->master;
                } else {
-                       err = w1_process_command_root(msg, m);
+                       err = w1_process_command_root(msg, m, nsp->portid);
                        goto out_cont;
                }
 
@@ -358,41 +539,24 @@ static void w1_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
                if (!mlen)
                        goto out_cont;
 
-               mutex_lock(&dev->mutex);
-
-               if (sl && w1_reset_select_slave(sl)) {
-                       err = -ENODEV;
-                       goto out_up;
-               }
+               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;
 
-               while (mlen) {
-                       cmd = (struct w1_netlink_cmd *)cmd_data;
+               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;
 
-                       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);
-
-                       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, nsp->portid, err);
+               msg_len -= sizeof(struct w1_netlink_msg) + m->len;
                m = (struct w1_netlink_msg *)(((u8 *)m) + sizeof(struct w1_netlink_msg) + m->len);
 
                /*
@@ -401,6 +565,8 @@ out_cont:
                if (err == -ENODEV)
                        err = 0;
        }
+       if (block && atomic_sub_return(1, &block->refcnt) == 0)
+               kfree(block);
 }
 
 int w1_init_netlink(void)