1 /*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * (C) Copyright 2020 Hewlett Packard Enterprise Development LP
7 * Copyright (c) 2004-2008 Silicon Graphics, Inc. All Rights Reserved.
8 */
9
10 /*
11 * Cross Partition (XP) base.
12 *
13 * XP provides a base from which its users can interact
14 * with XPC, yet not be dependent on XPC.
15 *
16 */
17
18 #include <linux/module.h>
19 #include <linux/device.h>
20 #include "xp.h"
21
22 /* define the XP debug device structures to be used with dev_dbg() et al */
23
24 static struct device_driver xp_dbg_name = {
25 .name = "xp"
26 };
27
28 static struct device xp_dbg_subname = {
29 .init_name = "", /* set to "" */
30 .driver = &xp_dbg_name
31 };
32
33 struct device *xp = &xp_dbg_subname;
34
35 /* max #of partitions possible */
36 short xp_max_npartitions;
37 EXPORT_SYMBOL_GPL(xp_max_npartitions);
38
39 short xp_partition_id;
40 EXPORT_SYMBOL_GPL(xp_partition_id);
41
42 u8 xp_region_size;
43 EXPORT_SYMBOL_GPL(xp_region_size);
44
45 unsigned long (*xp_pa) (void *addr);
46 EXPORT_SYMBOL_GPL(xp_pa);
47
48 unsigned long (*xp_socket_pa) (unsigned long gpa);
49 EXPORT_SYMBOL_GPL(xp_socket_pa);
50
51 enum xp_retval (*xp_remote_memcpy) (unsigned long dst_gpa,
52 const unsigned long src_gpa, size_t len);
53 EXPORT_SYMBOL_GPL(xp_remote_memcpy);
54
55 int (*xp_cpu_to_nasid) (int cpuid);
56 EXPORT_SYMBOL_GPL(xp_cpu_to_nasid);
57
58 enum xp_retval (*xp_expand_memprotect) (unsigned long phys_addr,
59 unsigned long size);
60 EXPORT_SYMBOL_GPL(xp_expand_memprotect);
61 enum xp_retval (*xp_restrict_memprotect) (unsigned long phys_addr,
62 unsigned long size);
63 EXPORT_SYMBOL_GPL(xp_restrict_memprotect);
64
65 /*
66 * xpc_registrations[] keeps track of xpc_connect()'s done by the kernel-level
67 * users of XPC.
68 */
69 struct xpc_registration xpc_registrations[XPC_MAX_NCHANNELS];
70 EXPORT_SYMBOL_GPL(xpc_registrations);
71
72 /*
73 * Initialize the XPC interface to NULL to indicate that XPC isn't loaded.
74 */
75 struct xpc_interface xpc_interface = { };
76 EXPORT_SYMBOL_GPL(xpc_interface);
77
78 /*
79 * XPC calls this when it (the XPC module) has been loaded.
80 */
81 void
xpc_set_interface(void (* connect)(int),void (* disconnect)(int),enum xp_retval (* send)(short,int,u32,void *,u16),enum xp_retval (* send_notify)(short,int,u32,void *,u16,xpc_notify_func,void *),void (* received)(short,int,void *),enum xp_retval (* partid_to_nasids)(short,void *))82 xpc_set_interface(void (*connect) (int),
83 void (*disconnect) (int),
84 enum xp_retval (*send) (short, int, u32, void *, u16),
85 enum xp_retval (*send_notify) (short, int, u32, void *, u16,
86 xpc_notify_func, void *),
87 void (*received) (short, int, void *),
88 enum xp_retval (*partid_to_nasids) (short, void *))
89 {
90 xpc_interface.connect = connect;
91 xpc_interface.disconnect = disconnect;
92 xpc_interface.send = send;
93 xpc_interface.send_notify = send_notify;
94 xpc_interface.received = received;
95 xpc_interface.partid_to_nasids = partid_to_nasids;
96 }
97 EXPORT_SYMBOL_GPL(xpc_set_interface);
98
99 /*
100 * XPC calls this when it (the XPC module) is being unloaded.
101 */
102 void
xpc_clear_interface(void)103 xpc_clear_interface(void)
104 {
105 memset(&xpc_interface, 0, sizeof(xpc_interface));
106 }
107 EXPORT_SYMBOL_GPL(xpc_clear_interface);
108
109 /*
110 * Register for automatic establishment of a channel connection whenever
111 * a partition comes up.
112 *
113 * Arguments:
114 *
115 * ch_number - channel # to register for connection.
116 * func - function to call for asynchronous notification of channel
117 * state changes (i.e., connection, disconnection, error) and
118 * the arrival of incoming messages.
119 * key - pointer to optional user-defined value that gets passed back
120 * to the user on any callouts made to func.
121 * payload_size - size in bytes of the XPC message's payload area which
122 * contains a user-defined message. The user should make
123 * this large enough to hold their largest message.
124 * nentries - max #of XPC message entries a message queue can contain.
125 * The actual number, which is determined when a connection
126 * is established and may be less then requested, will be
127 * passed to the user via the xpConnected callout.
128 * assigned_limit - max number of kthreads allowed to be processing
129 * messages (per connection) at any given instant.
130 * idle_limit - max number of kthreads allowed to be idle at any given
131 * instant.
132 */
133 enum xp_retval
xpc_connect(int ch_number,xpc_channel_func func,void * key,u16 payload_size,u16 nentries,u32 assigned_limit,u32 idle_limit)134 xpc_connect(int ch_number, xpc_channel_func func, void *key, u16 payload_size,
135 u16 nentries, u32 assigned_limit, u32 idle_limit)
136 {
137 struct xpc_registration *registration;
138
139 DBUG_ON(ch_number < 0 || ch_number >= XPC_MAX_NCHANNELS);
140 DBUG_ON(payload_size == 0 || nentries == 0);
141 DBUG_ON(func == NULL);
142 DBUG_ON(assigned_limit == 0 || idle_limit > assigned_limit);
143
144 if (XPC_MSG_SIZE(payload_size) > XPC_MSG_MAX_SIZE)
145 return xpPayloadTooBig;
146
147 registration = &xpc_registrations[ch_number];
148
149 if (mutex_lock_interruptible(®istration->mutex) != 0)
150 return xpInterrupted;
151
152 /* if XPC_CHANNEL_REGISTERED(ch_number) */
153 if (registration->func != NULL) {
154 mutex_unlock(®istration->mutex);
155 return xpAlreadyRegistered;
156 }
157
158 /* register the channel for connection */
159 registration->entry_size = XPC_MSG_SIZE(payload_size);
160 registration->nentries = nentries;
161 registration->assigned_limit = assigned_limit;
162 registration->idle_limit = idle_limit;
163 registration->key = key;
164 registration->func = func;
165
166 mutex_unlock(®istration->mutex);
167
168 if (xpc_interface.connect)
169 xpc_interface.connect(ch_number);
170
171 return xpSuccess;
172 }
173 EXPORT_SYMBOL_GPL(xpc_connect);
174
175 /*
176 * Remove the registration for automatic connection of the specified channel
177 * when a partition comes up.
178 *
179 * Before returning this xpc_disconnect() will wait for all connections on the
180 * specified channel have been closed/torndown. So the caller can be assured
181 * that they will not be receiving any more callouts from XPC to their
182 * function registered via xpc_connect().
183 *
184 * Arguments:
185 *
186 * ch_number - channel # to unregister.
187 */
188 void
xpc_disconnect(int ch_number)189 xpc_disconnect(int ch_number)
190 {
191 struct xpc_registration *registration;
192
193 DBUG_ON(ch_number < 0 || ch_number >= XPC_MAX_NCHANNELS);
194
195 registration = &xpc_registrations[ch_number];
196
197 /*
198 * We've decided not to make this a down_interruptible(), since we
199 * figured XPC's users will just turn around and call xpc_disconnect()
200 * again anyways, so we might as well wait, if need be.
201 */
202 mutex_lock(®istration->mutex);
203
204 /* if !XPC_CHANNEL_REGISTERED(ch_number) */
205 if (registration->func == NULL) {
206 mutex_unlock(®istration->mutex);
207 return;
208 }
209
210 /* remove the connection registration for the specified channel */
211 registration->func = NULL;
212 registration->key = NULL;
213 registration->nentries = 0;
214 registration->entry_size = 0;
215 registration->assigned_limit = 0;
216 registration->idle_limit = 0;
217
218 if (xpc_interface.disconnect)
219 xpc_interface.disconnect(ch_number);
220
221 mutex_unlock(®istration->mutex);
222
223 return;
224 }
225 EXPORT_SYMBOL_GPL(xpc_disconnect);
226
227 static int __init
xp_init(void)228 xp_init(void)
229 {
230 enum xp_retval ret;
231 int ch_number;
232
233 /* initialize the connection registration mutex */
234 for (ch_number = 0; ch_number < XPC_MAX_NCHANNELS; ch_number++)
235 mutex_init(&xpc_registrations[ch_number].mutex);
236
237 if (is_uv_system())
238 ret = xp_init_uv();
239 else
240 ret = 0;
241
242 if (ret != xpSuccess)
243 return ret;
244
245 return 0;
246 }
247
248 module_init(xp_init);
249
250 static void __exit
xp_exit(void)251 xp_exit(void)
252 {
253 if (is_uv_system())
254 xp_exit_uv();
255 }
256
257 module_exit(xp_exit);
258
259 MODULE_AUTHOR("Silicon Graphics, Inc.");
260 MODULE_DESCRIPTION("Cross Partition (XP) base");
261 MODULE_LICENSE("GPL");
262