Commit 8a0427d1 authored by David Fries's avatar David Fries Committed by Greg Kroah-Hartman
Browse files

w1: optional bundling of netlink kernel replies 

Applications can submit a set of commands in one packet to the kernel,
and in some cases it is required such as reading the temperature
sensor results.  This adds an option W1_CN_BUNDLE to the flags of
cn_msg to request the kernel to reply in one packet for efficiency.

The cn_msg flags now check for unknown flag values and return an error
if one is seen.  See "Proper handling of unknown flags in system
calls" http://lwn.net/Articles/588444/



This corrects the ack values returned as per the protocol standard,
namely the original ack for status messages and seq + 1 for all others
such as the data returned from a read.

Some of the common variable names have been standardized as follows.
struct cn_msg *cn
struct w1_netlink_msg *msg
struct w1_netlink_cmd *cmd
struct w1_master *dev

When an argument and a function scope variable would collide, add req_
to the argument.

Signed-off-by: default avatarDavid Fries <David@Fries.net>
Acked-by: default avatarEvgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 34470e0b

Documentation/connector/connector.txt

+1 −1
Original line number Diff line number Diff line
@@ -118,7 +118,7 @@ acknowledge number MUST be the same + 1. 
If we receive a message and its sequence number is not equal to one we

are expecting, then it is a new message.  If we receive a message and

its sequence number is the same as one we are expecting, but its

acknowledge is not equal to the acknowledge number in the original

acknowledge is not equal to the sequence number in the original

message + 1, then it is a new message.



Obviously, the protocol header contains the above id.

Documentation/w1/w1.generic

+1 −1
Original line number Diff line number Diff line
@@ -82,7 +82,7 @@ driver - (standard) symlink to the w1 driver 
w1_master_add      - Manually register a slave device

w1_master_attempts - the number of times a search was attempted

w1_master_max_slave_count

                   - the maximum slaves that may be attached to a master

                   - maximum number of slaves to search for at a time

w1_master_name     - the name of the device (w1_bus_masterX)

w1_master_pullup   - 5V strong pullup 0 enabled, 1 disabled

w1_master_remove   - Manually remove a slave device

Documentation/w1/w1.netlink

+8 −5
Original line number Diff line number Diff line
@@ -30,7 +30,7 @@ Protocol. 
			W1_SLAVE_CMD

				userspace command for slave device

				(read/write/touch)

	__u8 res	- reserved

	__u8 status	- error indication from kernel

	__u16 len	- size of data attached to this header data

	union {

		__u8 id[8];			 - slave unique device id
@@ -44,10 +44,14 @@ Protocol. 
	__u8 cmd	- command opcode.

			W1_CMD_READ 	- read command

			W1_CMD_WRITE	- write command

			W1_CMD_TOUCH	- touch command

				(write and sample data back to userspace)

			W1_CMD_SEARCH	- search command

			W1_CMD_ALARM_SEARCH - alarm search command

			W1_CMD_TOUCH	- touch command

				(write and sample data back to userspace)

			W1_CMD_RESET	- send bus reset

			W1_CMD_SLAVE_ADD	- add slave to kernel list

			W1_CMD_SLAVE_REMOVE	- remove slave from kernel list

			W1_CMD_LIST_SLAVES	- get slaves list from kernel

	__u8 res	- reserved

	__u16 len	- length of data for this command

		For read command data must be allocated like for write command
@@ -87,8 +91,7 @@ format: 
	id0 ... idN



	Each message is at most 4k in size, so if number of master devices

	exceeds this, it will be split into several messages,

	cn.seq will be increased for each one.

	exceeds this, it will be split into several messages.



W1 search and alarm search commands.

request:

drivers/w1/w1.h

+0 −8
Original line number Diff line number Diff line
@@ -203,7 +203,6 @@ enum w1_master_flags { 
 * @search_id:		allows continuing a search

 * @refcnt:		reference count

 * @priv:		private data storage

 * @priv_size:		size allocated

 * @enable_pullup:	allows a strong pullup

 * @pullup_duration:	time for the next strong pullup

 * @flags:		one of w1_master_flags
@@ -214,7 +213,6 @@ enum w1_master_flags { 
 * @dev:		sysfs device

 * @bus_master:		io operations available

 * @seq:		sequence number used for netlink broadcasts

 * @portid:		destination for the current netlink command

 */

struct w1_master

{
@@ -241,7 +239,6 @@ struct w1_master 
	atomic_t		refcnt;



	void			*priv;

	int			priv_size;



	/** 5V strong pullup enabled flag, 1 enabled, zero disabled. */

	int			enable_pullup;
@@ -260,11 +257,6 @@ struct w1_master 
	struct w1_bus_master	*bus_master;



	u32			seq;

	/* port id to send netlink responses to.  The value is temporarily

	 * stored here while processing a message, set after locking the

	 * mutex, zero before unlocking the mutex.

	 */

	u32			portid;

};



/**

drivers/w1/w1_netlink.c

+401 −248

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