caif: remove CAIF NETWORK LAYER

Remove CAIF (Communication CPU to Application CPU Interface), the
ST-Ericsson modem protocol. The subsystem has been orphaned since 2013.
The last meaningful changes from the maintainers were in March 2013:
  a8c7687bf216 ("caif_virtio: Check that vringh_config is not null")
  b2273be8d2df ("caif_virtio: Use vringh_notify_enable correctly")
  0d2e1a2926b1 ("caif_virtio: Introduce caif over virtio")

Not-so-coincidentally, according to "the Internet" ST-Ericsson officially
shut down its modem joint venture in Aug 2013.

If anyone is using this code please yell!

In the 13 years since, the code has accumulated 200 non-merge commits,
of which 71 were cross-tree API changes, 21 carried Fixes: tags, and
the remaining ~110 were cleanups, doc conversions, treewide refactors,
and one partial removal (caif_hsi, ca75bcf0a83b).

We are still getting fixes to this code, in the last 10 days there were
3 reports on security@ about CAIF that I have been CCed on.

UAPI constants (AF_CAIF, ARPHRD_CAIF, N_CAIF, VIRTIO_ID_CAIF) and the
SELinux classmap entry are intentionally kept for ABI stability.

Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260416182829.1440262-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 0 insertions, 130 deletions

diff --git a/include/net/caif/cfctrl.h b/include/net/caif/cfctrl.h
deleted file mode 100644
index 86d17315c8a1..000000000000
--- a/include/net/caif/cfctrl.h
+++ /dev/null
@@ -1,130 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Copyright (C) ST-Ericsson AB 2010
- * Author:	Sjur Brendeland
- */
-
-#ifndef CFCTRL_H_
-#define CFCTRL_H_
-#include <net/caif/caif_layer.h>
-#include <net/caif/cfsrvl.h>
-
-/* CAIF Control packet commands */
-enum cfctrl_cmd {
-	CFCTRL_CMD_LINK_SETUP = 0,
-	CFCTRL_CMD_LINK_DESTROY = 1,
-	CFCTRL_CMD_LINK_ERR = 2,
-	CFCTRL_CMD_ENUM = 3,
-	CFCTRL_CMD_SLEEP = 4,
-	CFCTRL_CMD_WAKE = 5,
-	CFCTRL_CMD_LINK_RECONF = 6,
-	CFCTRL_CMD_START_REASON = 7,
-	CFCTRL_CMD_RADIO_SET = 8,
-	CFCTRL_CMD_MODEM_SET = 9,
-	CFCTRL_CMD_MASK = 0xf
-};
-
-/* Channel types */
-enum cfctrl_srv {
-	CFCTRL_SRV_DECM = 0,
-	CFCTRL_SRV_VEI = 1,
-	CFCTRL_SRV_VIDEO = 2,
-	CFCTRL_SRV_DBG = 3,
-	CFCTRL_SRV_DATAGRAM = 4,
-	CFCTRL_SRV_RFM = 5,
-	CFCTRL_SRV_UTIL = 6,
-	CFCTRL_SRV_MASK = 0xf
-};
-
-#define CFCTRL_RSP_BIT 0x20
-#define CFCTRL_ERR_BIT 0x10
-
-struct cfctrl_rsp {
-	void (*linksetup_rsp)(struct cflayer *layer, u8 linkid,
-			      enum cfctrl_srv serv, u8 phyid,
-			      struct cflayer *adapt_layer);
-	void (*linkdestroy_rsp)(struct cflayer *layer, u8 linkid);
-	void (*linkerror_ind)(void);
-	void (*enum_rsp)(void);
-	void (*sleep_rsp)(void);
-	void (*wake_rsp)(void);
-	void (*restart_rsp)(void);
-	void (*radioset_rsp)(void);
-	void (*reject_rsp)(struct cflayer *layer, u8 linkid,
-				struct cflayer *client_layer);
-};
-
-/* Link Setup Parameters for CAIF-Links. */
-struct cfctrl_link_param {
-	enum cfctrl_srv linktype;/* (T3,T0) Type of Channel */
-	u8 priority;		  /* (P4,P0) Priority of the channel */
-	u8 phyid;		  /* (U2-U0) Physical interface to connect */
-	u8 endpoint;		  /* (E1,E0) Endpoint for data channels */
-	u8 chtype;		  /* (H1,H0) Channel-Type, applies to
-				   *            VEI, DEBUG */
-	union {
-		struct {
-			u8 connid;	/*  (D7,D0) Video LinkId */
-		} video;
-
-		struct {
-			u32 connid;	/* (N31,Ngit0) Connection ID used
-					 *  for Datagram */
-		} datagram;
-
-		struct {
-			u32 connid;	/* Connection ID used for RFM */
-			char volume[20];	/* Volume to mount for RFM */
-		} rfm;		/* Configuration for RFM */
-
-		struct {
-			u16 fifosize_kb;	/* Psock FIFO size in KB */
-			u16 fifosize_bufs;	/* Psock # signal buffers */
-			char name[16];	/* Name of the PSOCK service */
-			u8 params[255];	/* Link setup Parameters> */
-			u16 paramlen;	/* Length of Link Setup
-						 *   Parameters */
-		} utility;	/* Configuration for Utility Links (Psock) */
-	} u;
-};
-
-/* This structure is used internally in CFCTRL */
-struct cfctrl_request_info {
-	int sequence_no;
-	enum cfctrl_cmd cmd;
-	u8 channel_id;
-	struct cfctrl_link_param param;
-	struct cflayer *client_layer;
-	struct list_head list;
-};
-
-struct cfctrl {
-	struct cfsrvl serv;
-	struct cfctrl_rsp res;
-	atomic_t req_seq_no;
-	atomic_t rsp_seq_no;
-	struct list_head list;
-	/* Protects from simultaneous access to first_req list */
-	spinlock_t info_list_lock;
-#ifndef CAIF_NO_LOOP
-	u8 loop_linkid;
-	int loop_linkused[256];
-	/* Protects simultaneous access to loop_linkid and loop_linkused */
-	spinlock_t loop_linkid_lock;
-#endif
-
-};
-
-void cfctrl_enum_req(struct cflayer *cfctrl, u8 physlinkid);
-int cfctrl_linkup_request(struct cflayer *cfctrl,
-			   struct cfctrl_link_param *param,
-			   struct cflayer *user_layer);
-int  cfctrl_linkdown_req(struct cflayer *cfctrl, u8 linkid,
-			 struct cflayer *client);
-
-struct cflayer *cfctrl_create(void);
-struct cfctrl_rsp *cfctrl_get_respfuncs(struct cflayer *layer);
-int cfctrl_cancel_req(struct cflayer *layr, struct cflayer *adap_layer);
-void cfctrl_remove(struct cflayer *layr);
-
-#endif				/* CFCTRL_H_ */