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w1: new netlink commands, add/remove/list slaves
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Introduce new commands to add, remove, and list slave devices through
the netlink interface.  This can be useful to skip the search on a
static network.  They could previously only be added or removed
through automatic search or sysfs, and this allows a program to only
use netlink.

Only allocate memory when needed, so move kzalloc into w1_get_slaves
where it was used.

Signed-off-by: David Fries <David@Fries.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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David Fries authored and Greg Kroah-Hartman committed Feb 7, 2014
1 parent 3c6955e commit 70b34d2
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Showing 4 changed files with 126 additions and 39 deletions.
6 changes: 2 additions & 4 deletions drivers/w1/w1.c
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Original file line number Diff line number Diff line change
Expand Up @@ -56,8 +56,6 @@ module_param_named(slave_ttl, w1_max_slave_ttl, int, 0);
DEFINE_MUTEX(w1_mlock);
LIST_HEAD(w1_masters);

static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn);

static int w1_master_match(struct device *dev, struct device_driver *drv)
{
return 1;
Expand Down Expand Up @@ -444,7 +442,7 @@ static int w1_atoreg_num(struct device *dev, const char *buf, size_t count,
/* Searches the slaves in the w1_master and returns a pointer or NULL.
* Note: must hold the mutex
*/
static struct w1_slave *w1_slave_search_device(struct w1_master *dev,
struct w1_slave *w1_slave_search_device(struct w1_master *dev,
struct w1_reg_num *rn)
{
struct w1_slave *sl;
Expand Down Expand Up @@ -711,7 +709,7 @@ static int __w1_attach_slave_device(struct w1_slave *sl)
return 0;
}

static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
{
struct w1_slave *sl;
struct w1_family *f;
Expand Down
3 changes: 3 additions & 0 deletions drivers/w1/w1.h
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Original file line number Diff line number Diff line change
Expand Up @@ -213,6 +213,8 @@ struct w1_slave *w1_search_slave(struct w1_reg_num *id);
void w1_slave_found(struct w1_master *dev, u64 rn);
void w1_search_process_cb(struct w1_master *dev, u8 search_type,
w1_slave_found_callback cb);
struct w1_slave *w1_slave_search_device(struct w1_master *dev,
struct w1_reg_num *rn);
struct w1_master *w1_search_master_id(u32 id);

/* Disconnect and reconnect devices in the given family. Used for finding
Expand All @@ -221,6 +223,7 @@ struct w1_master *w1_search_master_id(u32 id);
* has just been registered, to 0 when it has been unregistered.
*/
void w1_reconnect_slaves(struct w1_family *f, int attach);
int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn);
void w1_slave_detach(struct w1_slave *sl);

u8 w1_triplet(struct w1_master *dev, int bdir);
Expand Down
125 changes: 91 additions & 34 deletions drivers/w1/w1_netlink.c
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Original file line number Diff line number Diff line change
Expand Up @@ -56,9 +56,6 @@ 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) {
Expand All @@ -79,24 +76,66 @@ 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);

w1_send_slave(dev, rn);
}

/* 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;
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 = avail;
dev->priv_size = PAGE_SIZE - msg->len - sizeof(struct cn_msg);

w1_search_process_cb(dev, search_type, w1_send_slave);
if (req_cmd->cmd == W1_CMD_LIST_SLAVES) {
__u64 rn;
list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
memcpy(&rn, &sl->reg_num, sizeof(rn));
w1_send_slave(dev, rn);
}
} 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, 0, GFP_KERNEL);

dev->priv = NULL;
dev->priv_size = 0;

kfree(msg);

return 0;
}

Expand Down Expand Up @@ -164,38 +203,52 @@ 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) {
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:
err = w1_get_slaves(dev, req_msg, req_hdr, req_cmd);
break;
case W1_CMD_READ:
case W1_CMD_WRITE:
Expand All @@ -205,12 +258,16 @@ 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:
err = w1_process_command_addremove(dev, req_msg, req_hdr,
req_cmd);
break;
default:
err = -EINVAL;
break;
}

kfree(msg);
return err;
}

Expand Down
31 changes: 30 additions & 1 deletion drivers/w1/w1_netlink.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -27,6 +27,17 @@

#include "w1.h"

/** enum w1_netlink_message_types - message type
*
* @W1_SLAVE_ADD: notification that a slave device was added
* @W1_SLAVE_REMOVE: notification that a slave device was removed
* @W1_MASTER_ADD: notification that a new bus master was added
* @W1_MASTER_REMOVE: notification that a bus masterwas removed
* @W1_MASTER_CMD: initiate operations on a specific master
* @W1_SLAVE_CMD: sends reset, selects the slave, then does a read/write/touch
* operation
* @W1_LIST_MASTERS: used to determine the bus master identifiers
*/
enum w1_netlink_message_types {
W1_SLAVE_ADD = 0,
W1_SLAVE_REMOVE,
Expand All @@ -52,14 +63,32 @@ struct w1_netlink_msg
__u8 data[0];
};

/** enum w1_commands - commands available for master or slave operations
* @W1_CMD_READ: read len bytes
* @W1_CMD_WRITE: write len bytes
* @W1_CMD_SEARCH: initiate a standard search, returns only the slave
* devices found during that search
* @W1_CMD_ALARM_SEARCH: search for devices that are currently alarming
* @W1_CMD_TOUCH: Touches a series of bytes.
* @W1_CMD_RESET: sends a bus reset on the given master
* @W1_CMD_SLAVE_ADD: adds a slave to the given master,
* 8 byte slave id at data[0]
* @W1_CMD_SLAVE_REMOVE: removes a slave to the given master,
* 8 byte slave id at data[0]
* @W1_CMD_LIST_SLAVES: list of slaves registered on this master
* @W1_CMD_MAX: number of available commands
*/
enum w1_commands {
W1_CMD_READ = 0,
W1_CMD_WRITE,
W1_CMD_SEARCH,
W1_CMD_ALARM_SEARCH,
W1_CMD_TOUCH,
W1_CMD_RESET,
W1_CMD_MAX,
W1_CMD_SLAVE_ADD,
W1_CMD_SLAVE_REMOVE,
W1_CMD_LIST_SLAVES,
W1_CMD_MAX
};

struct w1_netlink_cmd
Expand Down

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