android_kernel_xiaomi_sm8350/include/net/iucv/iucv.h
Martin Schwidefsky 04b090d50c [AF_IUCV/IUCV]: smp_call_function deadlock
Calling smp_call_function can lead to a deadlock if it is called
from tasklet context. 
Fixing this deadlock requires to move the smp_call_function from the
tasklet context to a work queue. To do that queue the path pending
interrupts to a separate list and move the path cleanup out of
iucv_path_sever to iucv_path_connect and iucv_path_pending.
This creates a new requirement for iucv_path_connect: it may not be
called from tasklet context anymore. 
Also fixed compile problem for CONFIG_HOTPLUG_CPU=n and
another one when walking the cpu_online mask. When doing this, 
we must disable cpu hotplug.

Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-28 23:03:59 -07:00

416 lines
14 KiB
C

/*
* drivers/s390/net/iucv.h
* IUCV base support.
*
* S390 version
* Copyright 2000, 2006 IBM Corporation
* Author(s):Alan Altmark (Alan_Altmark@us.ibm.com)
* Xenia Tkatschow (xenia@us.ibm.com)
* Rewritten for af_iucv:
* Martin Schwidefsky <schwidefsky@de.ibm.com>
*
*
* Functionality:
* To explore any of the IUCV functions, one must first register their
* program using iucv_register(). Once your program has successfully
* completed a register, it can exploit the other functions.
* For furthur reference on all IUCV functionality, refer to the
* CP Programming Services book, also available on the web thru
* www.vm.ibm.com/pubs, manual # SC24-6084
*
* Definition of Return Codes
* - All positive return codes including zero are reflected back
* from CP. The definition of each return code can be found in
* CP Programming Services book.
* - Return Code of:
* -EINVAL: Invalid value
* -ENOMEM: storage allocation failed
*/
#include <linux/types.h>
#include <asm/debug.h>
/*
* IUCV option flags usable by device drivers:
*
* IUCV_IPRMDATA Indicates that your program can handle a message in the
* parameter list / a message is sent in the parameter list.
* Used for iucv_path_accept, iucv_path_connect,
* iucv_message_reply, iucv_message_send, iucv_message_send2way.
* IUCV_IPQUSCE Indicates that you do not want to receive messages on this
* path until an iucv_path_resume is issued.
* Used for iucv_path_accept, iucv_path_connect.
* IUCV_IPBUFLST Indicates that an address list is used for the message data.
* Used for iucv_message_receive, iucv_message_send,
* iucv_message_send2way.
* IUCV_IPPRTY Specifies that you want to send priority messages.
* Used for iucv_path_accept, iucv_path_connect,
* iucv_message_reply, iucv_message_send, iucv_message_send2way.
* IUCV_IPSYNC Indicates a synchronous send request.
* Used for iucv_message_send, iucv_message_send2way.
* IUCV_IPANSLST Indicates that an address list is used for the reply data.
* Used for iucv_message_reply, iucv_message_send2way.
* IUCV_IPLOCAL Specifies that the communication partner has to be on the
* local system. If local is specified no target class can be
* specified.
* Used for iucv_path_connect.
*
* All flags are defined in the input field IPFLAGS1 of each function
* and can be found in CP Programming Services.
*/
#define IUCV_IPRMDATA 0x80
#define IUCV_IPQUSCE 0x40
#define IUCV_IPBUFLST 0x40
#define IUCV_IPPRTY 0x20
#define IUCV_IPANSLST 0x08
#define IUCV_IPSYNC 0x04
#define IUCV_IPLOCAL 0x01
/*
* iucv_array : Defines buffer array.
* Inside the array may be 31- bit addresses and 31-bit lengths.
* Use a pointer to an iucv_array as the buffer, reply or answer
* parameter on iucv_message_send, iucv_message_send2way, iucv_message_receive
* and iucv_message_reply if IUCV_IPBUFLST or IUCV_IPANSLST are used.
*/
struct iucv_array {
u32 address;
u32 length;
} __attribute__ ((aligned (8)));
extern struct bus_type iucv_bus;
extern struct device *iucv_root;
/*
* struct iucv_path
* pathid: 16 bit path identification
* msglim: 16 bit message limit
* flags: properties of the path: IPRMDATA, IPQUSCE, IPPRTY
* handler: address of iucv handler structure
* private: private information of the handler associated with the path
* list: list_head for the iucv_handler path list.
*/
struct iucv_path {
u16 pathid;
u16 msglim;
u8 flags;
void *private;
struct iucv_handler *handler;
struct list_head list;
};
/*
* struct iucv_message
* id: 32 bit message id
* audit: 32 bit error information of purged or replied messages
* class: 32 bit target class of a message (source class for replies)
* tag: 32 bit tag to be associated with the message
* length: 32 bit length of the message / reply
* reply_size: 32 bit maximum allowed length of the reply
* rmmsg: 8 byte inline message
* flags: message properties (IUCV_IPPRTY)
*/
struct iucv_message {
u32 id;
u32 audit;
u32 class;
u32 tag;
u32 length;
u32 reply_size;
u8 rmmsg[8];
u8 flags;
};
/*
* struct iucv_handler
*
* A vector of functions that handle IUCV interrupts. Each functions gets
* a parameter area as defined by the CP Programming Services and private
* pointer that is provided by the user of the interface.
*/
struct iucv_handler {
/*
* The path_pending function is called after an iucv interrupt
* type 0x01 has been received. The base code allocates a path
* structure and "asks" the handler if this path belongs to the
* handler. To accept the path the path_pending function needs
* to call iucv_path_accept and return 0. If the callback returns
* a value != 0 the iucv base code will continue with the next
* handler. The order in which the path_pending functions are
* called is the order of the registration of the iucv handlers
* to the base code.
*/
int (*path_pending)(struct iucv_path *, u8 ipvmid[8], u8 ipuser[16]);
/*
* The path_complete function is called after an iucv interrupt
* type 0x02 has been received for a path that has been established
* for this handler with iucv_path_connect and got accepted by the
* peer with iucv_path_accept.
*/
void (*path_complete)(struct iucv_path *, u8 ipuser[16]);
/*
* The path_severed function is called after an iucv interrupt
* type 0x03 has been received. The communication peer shutdown
* his end of the communication path. The path still exists and
* remaining messages can be received until a iucv_path_sever
* shuts down the other end of the path as well.
*/
void (*path_severed)(struct iucv_path *, u8 ipuser[16]);
/*
* The path_quiesced function is called after an icuv interrupt
* type 0x04 has been received. The communication peer has quiesced
* the path. Delivery of messages is stopped until iucv_path_resume
* has been called.
*/
void (*path_quiesced)(struct iucv_path *, u8 ipuser[16]);
/*
* The path_resumed function is called after an icuv interrupt
* type 0x05 has been received. The communication peer has resumed
* the path.
*/
void (*path_resumed)(struct iucv_path *, u8 ipuser[16]);
/*
* The message_pending function is called after an icuv interrupt
* type 0x06 or type 0x07 has been received. A new message is
* availabe and can be received with iucv_message_receive.
*/
void (*message_pending)(struct iucv_path *, struct iucv_message *);
/*
* The message_complete function is called after an icuv interrupt
* type 0x08 or type 0x09 has been received. A message send with
* iucv_message_send2way has been replied to. The reply can be
* received with iucv_message_receive.
*/
void (*message_complete)(struct iucv_path *, struct iucv_message *);
struct list_head list;
struct list_head paths;
};
/**
* iucv_register:
* @handler: address of iucv handler structure
* @smp: != 0 indicates that the handler can deal with out of order messages
*
* Registers a driver with IUCV.
*
* Returns 0 on success, -ENOMEM if the memory allocation for the pathid
* table failed, or -EIO if IUCV_DECLARE_BUFFER failed on all cpus.
*/
int iucv_register(struct iucv_handler *handler, int smp);
/**
* iucv_unregister
* @handler: address of iucv handler structure
* @smp: != 0 indicates that the handler can deal with out of order messages
*
* Unregister driver from IUCV.
*/
void iucv_unregister(struct iucv_handler *handle, int smp);
/**
* iucv_path_alloc
* @msglim: initial message limit
* @flags: initial flags
* @gfp: kmalloc allocation flag
*
* Allocate a new path structure for use with iucv_connect.
*
* Returns NULL if the memory allocation failed or a pointer to the
* path structure.
*/
static inline struct iucv_path *iucv_path_alloc(u16 msglim, u8 flags, gfp_t gfp)
{
struct iucv_path *path;
path = kzalloc(sizeof(struct iucv_path), gfp);
if (path) {
path->msglim = msglim;
path->flags = flags;
}
return path;
}
/**
* iucv_path_free
* @path: address of iucv path structure
*
* Frees a path structure.
*/
static inline void iucv_path_free(struct iucv_path *path)
{
kfree(path);
}
/**
* iucv_path_accept
* @path: address of iucv path structure
* @handler: address of iucv handler structure
* @userdata: 16 bytes of data reflected to the communication partner
* @private: private data passed to interrupt handlers for this path
*
* This function is issued after the user received a connection pending
* external interrupt and now wishes to complete the IUCV communication path.
*
* Returns the result of the CP IUCV call.
*/
int iucv_path_accept(struct iucv_path *path, struct iucv_handler *handler,
u8 userdata[16], void *private);
/**
* iucv_path_connect
* @path: address of iucv path structure
* @handler: address of iucv handler structure
* @userid: 8-byte user identification
* @system: 8-byte target system identification
* @userdata: 16 bytes of data reflected to the communication partner
* @private: private data passed to interrupt handlers for this path
*
* This function establishes an IUCV path. Although the connect may complete
* successfully, you are not able to use the path until you receive an IUCV
* Connection Complete external interrupt.
*
* Returns the result of the CP IUCV call.
*/
int iucv_path_connect(struct iucv_path *path, struct iucv_handler *handler,
u8 userid[8], u8 system[8], u8 userdata[16],
void *private);
/**
* iucv_path_quiesce:
* @path: address of iucv path structure
* @userdata: 16 bytes of data reflected to the communication partner
*
* This function temporarily suspends incoming messages on an IUCV path.
* You can later reactivate the path by invoking the iucv_resume function.
*
* Returns the result from the CP IUCV call.
*/
int iucv_path_quiesce(struct iucv_path *path, u8 userdata[16]);
/**
* iucv_path_resume:
* @path: address of iucv path structure
* @userdata: 16 bytes of data reflected to the communication partner
*
* This function resumes incoming messages on an IUCV path that has
* been stopped with iucv_path_quiesce.
*
* Returns the result from the CP IUCV call.
*/
int iucv_path_resume(struct iucv_path *path, u8 userdata[16]);
/**
* iucv_path_sever
* @path: address of iucv path structure
* @userdata: 16 bytes of data reflected to the communication partner
*
* This function terminates an IUCV path.
*
* Returns the result from the CP IUCV call.
*/
int iucv_path_sever(struct iucv_path *path, u8 userdata[16]);
/**
* iucv_message_purge
* @path: address of iucv path structure
* @msg: address of iucv msg structure
* @srccls: source class of message
*
* Cancels a message you have sent.
*
* Returns the result from the CP IUCV call.
*/
int iucv_message_purge(struct iucv_path *path, struct iucv_message *msg,
u32 srccls);
/**
* iucv_message_receive
* @path: address of iucv path structure
* @msg: address of iucv msg structure
* @flags: flags that affect how the message is received (IUCV_IPBUFLST)
* @buffer: address of data buffer or address of struct iucv_array
* @size: length of data buffer
* @residual:
*
* This function receives messages that are being sent to you over
* established paths. This function will deal with RMDATA messages
* embedded in struct iucv_message as well.
*
* Returns the result from the CP IUCV call.
*/
int iucv_message_receive(struct iucv_path *path, struct iucv_message *msg,
u8 flags, void *buffer, size_t size, size_t *residual);
/**
* iucv_message_reject
* @path: address of iucv path structure
* @msg: address of iucv msg structure
*
* The reject function refuses a specified message. Between the time you
* are notified of a message and the time that you complete the message,
* the message may be rejected.
*
* Returns the result from the CP IUCV call.
*/
int iucv_message_reject(struct iucv_path *path, struct iucv_message *msg);
/**
* iucv_message_reply
* @path: address of iucv path structure
* @msg: address of iucv msg structure
* @flags: how the reply is sent (IUCV_IPRMDATA, IUCV_IPPRTY, IUCV_IPBUFLST)
* @reply: address of data buffer or address of struct iucv_array
* @size: length of reply data buffer
*
* This function responds to the two-way messages that you receive. You
* must identify completely the message to which you wish to reply. ie,
* pathid, msgid, and trgcls. Prmmsg signifies the data is moved into
* the parameter list.
*
* Returns the result from the CP IUCV call.
*/
int iucv_message_reply(struct iucv_path *path, struct iucv_message *msg,
u8 flags, void *reply, size_t size);
/**
* iucv_message_send
* @path: address of iucv path structure
* @msg: address of iucv msg structure
* @flags: how the message is sent (IUCV_IPRMDATA, IUCV_IPPRTY, IUCV_IPBUFLST)
* @srccls: source class of message
* @buffer: address of data buffer or address of struct iucv_array
* @size: length of send buffer
*
* This function transmits data to another application. Data to be
* transmitted is in a buffer and this is a one-way message and the
* receiver will not reply to the message.
*
* Returns the result from the CP IUCV call.
*/
int iucv_message_send(struct iucv_path *path, struct iucv_message *msg,
u8 flags, u32 srccls, void *buffer, size_t size);
/**
* iucv_message_send2way
* @path: address of iucv path structure
* @msg: address of iucv msg structure
* @flags: how the message is sent and the reply is received
* (IUCV_IPRMDATA, IUCV_IPBUFLST, IUCV_IPPRTY, IUCV_ANSLST)
* @srccls: source class of message
* @buffer: address of data buffer or address of struct iucv_array
* @size: length of send buffer
* @ansbuf: address of answer buffer or address of struct iucv_array
* @asize: size of reply buffer
*
* This function transmits data to another application. Data to be
* transmitted is in a buffer. The receiver of the send is expected to
* reply to the message and a buffer is provided into which IUCV moves
* the reply to this message.
*
* Returns the result from the CP IUCV call.
*/
int iucv_message_send2way(struct iucv_path *path, struct iucv_message *msg,
u8 flags, u32 srccls, void *buffer, size_t size,
void *answer, size_t asize, size_t *residual);