1 /*
2 * Copyright (C) 2001 Mike Corrigan IBM Corporation
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 */
9
10 #include <linux/stddef.h>
11 #include <linux/kernel.h>
12 #include <linux/sched.h>
13 #include <linux/bootmem.h>
14 #include <linux/seq_file.h>
15 #include <linux/proc_fs.h>
16 #include <linux/module.h>
17
18 #include <asm/system.h>
19 #include <asm/paca.h>
20 #include <asm/firmware.h>
21 #include <asm/iseries/it_lp_queue.h>
22 #include <asm/iseries/hv_lp_event.h>
23 #include <asm/iseries/hv_call_event.h>
24 #include "it_lp_naca.h"
25
26 /*
27 * The LpQueue is used to pass event data from the hypervisor to
28 * the partition. This is where I/O interrupt events are communicated.
29 *
30 * It is written to by the hypervisor so cannot end up in the BSS.
31 */
32 struct hvlpevent_queue hvlpevent_queue __attribute__((__section__(".data")));
33
34 DEFINE_PER_CPU(unsigned long[HvLpEvent_Type_NumTypes], hvlpevent_counts);
35
36 static char *event_types[HvLpEvent_Type_NumTypes] = {
37 "Hypervisor",
38 "Machine Facilities",
39 "Session Manager",
40 "SPD I/O",
41 "Virtual Bus",
42 "PCI I/O",
43 "RIO I/O",
44 "Virtual Lan",
45 "Virtual I/O"
46 };
47
48 /* Array of LpEvent handler functions */
49 static LpEventHandler lpEventHandler[HvLpEvent_Type_NumTypes];
50 static unsigned lpEventHandlerPaths[HvLpEvent_Type_NumTypes];
51
get_next_hvlpevent(void)52 static struct HvLpEvent * get_next_hvlpevent(void)
53 {
54 struct HvLpEvent * event;
55 event = (struct HvLpEvent *)hvlpevent_queue.hq_current_event;
56
57 if (hvlpevent_is_valid(event)) {
58 /* rmb() needed only for weakly consistent machines (regatta) */
59 rmb();
60 /* Set pointer to next potential event */
61 hvlpevent_queue.hq_current_event += ((event->xSizeMinus1 +
62 IT_LP_EVENT_ALIGN) / IT_LP_EVENT_ALIGN) *
63 IT_LP_EVENT_ALIGN;
64
65 /* Wrap to beginning if no room at end */
66 if (hvlpevent_queue.hq_current_event >
67 hvlpevent_queue.hq_last_event) {
68 hvlpevent_queue.hq_current_event =
69 hvlpevent_queue.hq_event_stack;
70 }
71 } else {
72 event = NULL;
73 }
74
75 return event;
76 }
77
78 static unsigned long spread_lpevents = NR_CPUS;
79
hvlpevent_is_pending(void)80 int hvlpevent_is_pending(void)
81 {
82 struct HvLpEvent *next_event;
83
84 if (smp_processor_id() >= spread_lpevents)
85 return 0;
86
87 next_event = (struct HvLpEvent *)hvlpevent_queue.hq_current_event;
88
89 return hvlpevent_is_valid(next_event) ||
90 hvlpevent_queue.hq_overflow_pending;
91 }
92
hvlpevent_clear_valid(struct HvLpEvent * event)93 static void hvlpevent_clear_valid(struct HvLpEvent * event)
94 {
95 /* Tell the Hypervisor that we're done with this event.
96 * Also clear bits within this event that might look like valid bits.
97 * ie. on 64-byte boundaries.
98 */
99 struct HvLpEvent *tmp;
100 unsigned extra = ((event->xSizeMinus1 + IT_LP_EVENT_ALIGN) /
101 IT_LP_EVENT_ALIGN) - 1;
102
103 switch (extra) {
104 case 3:
105 tmp = (struct HvLpEvent*)((char*)event + 3 * IT_LP_EVENT_ALIGN);
106 hvlpevent_invalidate(tmp);
107 case 2:
108 tmp = (struct HvLpEvent*)((char*)event + 2 * IT_LP_EVENT_ALIGN);
109 hvlpevent_invalidate(tmp);
110 case 1:
111 tmp = (struct HvLpEvent*)((char*)event + 1 * IT_LP_EVENT_ALIGN);
112 hvlpevent_invalidate(tmp);
113 }
114
115 mb();
116
117 hvlpevent_invalidate(event);
118 }
119
process_hvlpevents(void)120 void process_hvlpevents(void)
121 {
122 struct HvLpEvent * event;
123
124 restart:
125 /* If we have recursed, just return */
126 if (!spin_trylock(&hvlpevent_queue.hq_lock))
127 return;
128
129 for (;;) {
130 event = get_next_hvlpevent();
131 if (event) {
132 /* Call appropriate handler here, passing
133 * a pointer to the LpEvent. The handler
134 * must make a copy of the LpEvent if it
135 * needs it in a bottom half. (perhaps for
136 * an ACK)
137 *
138 * Handlers are responsible for ACK processing
139 *
140 * The Hypervisor guarantees that LpEvents will
141 * only be delivered with types that we have
142 * registered for, so no type check is necessary
143 * here!
144 */
145 if (event->xType < HvLpEvent_Type_NumTypes)
146 __get_cpu_var(hvlpevent_counts)[event->xType]++;
147 if (event->xType < HvLpEvent_Type_NumTypes &&
148 lpEventHandler[event->xType])
149 lpEventHandler[event->xType](event);
150 else {
151 u8 type = event->xType;
152
153 /*
154 * Don't printk in the spinlock as printk
155 * may require ack events form the HV to send
156 * any characters there.
157 */
158 hvlpevent_clear_valid(event);
159 spin_unlock(&hvlpevent_queue.hq_lock);
160 printk(KERN_INFO
161 "Unexpected Lp Event type=%d\n", type);
162 goto restart;
163 }
164
165 hvlpevent_clear_valid(event);
166 } else if (hvlpevent_queue.hq_overflow_pending)
167 /*
168 * No more valid events. If overflow events are
169 * pending process them
170 */
171 HvCallEvent_getOverflowLpEvents(hvlpevent_queue.hq_index);
172 else
173 break;
174 }
175
176 spin_unlock(&hvlpevent_queue.hq_lock);
177 }
178
set_spread_lpevents(char * str)179 static int set_spread_lpevents(char *str)
180 {
181 unsigned long val = simple_strtoul(str, NULL, 0);
182
183 /*
184 * The parameter is the number of processors to share in processing
185 * lp events.
186 */
187 if (( val > 0) && (val <= NR_CPUS)) {
188 spread_lpevents = val;
189 printk("lpevent processing spread over %ld processors\n", val);
190 } else {
191 printk("invalid spread_lpevents %ld\n", val);
192 }
193
194 return 1;
195 }
196 __setup("spread_lpevents=", set_spread_lpevents);
197
setup_hvlpevent_queue(void)198 void __init setup_hvlpevent_queue(void)
199 {
200 void *eventStack;
201
202 spin_lock_init(&hvlpevent_queue.hq_lock);
203
204 /* Allocate a page for the Event Stack. */
205 eventStack = alloc_bootmem_pages(IT_LP_EVENT_STACK_SIZE);
206 memset(eventStack, 0, IT_LP_EVENT_STACK_SIZE);
207
208 /* Invoke the hypervisor to initialize the event stack */
209 HvCallEvent_setLpEventStack(0, eventStack, IT_LP_EVENT_STACK_SIZE);
210
211 hvlpevent_queue.hq_event_stack = eventStack;
212 hvlpevent_queue.hq_current_event = eventStack;
213 hvlpevent_queue.hq_last_event = (char *)eventStack +
214 (IT_LP_EVENT_STACK_SIZE - IT_LP_EVENT_MAX_SIZE);
215 hvlpevent_queue.hq_index = 0;
216 }
217
218 /* Register a handler for an LpEvent type */
HvLpEvent_registerHandler(HvLpEvent_Type eventType,LpEventHandler handler)219 int HvLpEvent_registerHandler(HvLpEvent_Type eventType, LpEventHandler handler)
220 {
221 if (eventType < HvLpEvent_Type_NumTypes) {
222 lpEventHandler[eventType] = handler;
223 return 0;
224 }
225 return 1;
226 }
227 EXPORT_SYMBOL(HvLpEvent_registerHandler);
228
HvLpEvent_unregisterHandler(HvLpEvent_Type eventType)229 int HvLpEvent_unregisterHandler(HvLpEvent_Type eventType)
230 {
231 might_sleep();
232
233 if (eventType < HvLpEvent_Type_NumTypes) {
234 if (!lpEventHandlerPaths[eventType]) {
235 lpEventHandler[eventType] = NULL;
236 /*
237 * We now sleep until all other CPUs have scheduled.
238 * This ensures that the deletion is seen by all
239 * other CPUs, and that the deleted handler isn't
240 * still running on another CPU when we return.
241 */
242 synchronize_sched();
243 return 0;
244 }
245 }
246 return 1;
247 }
248 EXPORT_SYMBOL(HvLpEvent_unregisterHandler);
249
250 /*
251 * lpIndex is the partition index of the target partition.
252 * needed only for VirtualIo, VirtualLan and SessionMgr. Zero
253 * indicates to use our partition index - for the other types.
254 */
HvLpEvent_openPath(HvLpEvent_Type eventType,HvLpIndex lpIndex)255 int HvLpEvent_openPath(HvLpEvent_Type eventType, HvLpIndex lpIndex)
256 {
257 if ((eventType < HvLpEvent_Type_NumTypes) &&
258 lpEventHandler[eventType]) {
259 if (lpIndex == 0)
260 lpIndex = itLpNaca.xLpIndex;
261 HvCallEvent_openLpEventPath(lpIndex, eventType);
262 ++lpEventHandlerPaths[eventType];
263 return 0;
264 }
265 return 1;
266 }
267
HvLpEvent_closePath(HvLpEvent_Type eventType,HvLpIndex lpIndex)268 int HvLpEvent_closePath(HvLpEvent_Type eventType, HvLpIndex lpIndex)
269 {
270 if ((eventType < HvLpEvent_Type_NumTypes) &&
271 lpEventHandler[eventType] &&
272 lpEventHandlerPaths[eventType]) {
273 if (lpIndex == 0)
274 lpIndex = itLpNaca.xLpIndex;
275 HvCallEvent_closeLpEventPath(lpIndex, eventType);
276 --lpEventHandlerPaths[eventType];
277 return 0;
278 }
279 return 1;
280 }
281
proc_lpevents_show(struct seq_file * m,void * v)282 static int proc_lpevents_show(struct seq_file *m, void *v)
283 {
284 int cpu, i;
285 unsigned long sum;
286 static unsigned long cpu_totals[NR_CPUS];
287
288 /* FIXME: do we care that there's no locking here? */
289 sum = 0;
290 for_each_online_cpu(cpu) {
291 cpu_totals[cpu] = 0;
292 for (i = 0; i < HvLpEvent_Type_NumTypes; i++) {
293 cpu_totals[cpu] += per_cpu(hvlpevent_counts, cpu)[i];
294 }
295 sum += cpu_totals[cpu];
296 }
297
298 seq_printf(m, "LpEventQueue 0\n");
299 seq_printf(m, " events processed:\t%lu\n", sum);
300
301 for (i = 0; i < HvLpEvent_Type_NumTypes; ++i) {
302 sum = 0;
303 for_each_online_cpu(cpu) {
304 sum += per_cpu(hvlpevent_counts, cpu)[i];
305 }
306
307 seq_printf(m, " %-20s %10lu\n", event_types[i], sum);
308 }
309
310 seq_printf(m, "\n events processed by processor:\n");
311
312 for_each_online_cpu(cpu) {
313 seq_printf(m, " CPU%02d %10lu\n", cpu, cpu_totals[cpu]);
314 }
315
316 return 0;
317 }
318
proc_lpevents_open(struct inode * inode,struct file * file)319 static int proc_lpevents_open(struct inode *inode, struct file *file)
320 {
321 return single_open(file, proc_lpevents_show, NULL);
322 }
323
324 static const struct file_operations proc_lpevents_operations = {
325 .open = proc_lpevents_open,
326 .read = seq_read,
327 .llseek = seq_lseek,
328 .release = single_release,
329 };
330
proc_lpevents_init(void)331 static int __init proc_lpevents_init(void)
332 {
333 if (!firmware_has_feature(FW_FEATURE_ISERIES))
334 return 0;
335
336 proc_create("iSeries/lpevents", S_IFREG|S_IRUGO, NULL,
337 &proc_lpevents_operations);
338 return 0;
339 }
340 __initcall(proc_lpevents_init);
341
342