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Commit | Line | Data |
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5ab5ab34 DS |
1 | /* |
2 | * SGI RTC clock/timer routines. | |
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 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, write to the Free Software | |
16 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
17 | * | |
0af63520 | 18 | * Copyright (c) 2009-2013 Silicon Graphics, Inc. All Rights Reserved. |
5ab5ab34 DS |
19 | * Copyright (c) Dimitri Sivanich |
20 | */ | |
21 | #include <linux/clockchips.h> | |
5a0e3ad6 | 22 | #include <linux/slab.h> |
5ab5ab34 DS |
23 | |
24 | #include <asm/uv/uv_mmrs.h> | |
25 | #include <asm/uv/uv_hub.h> | |
26 | #include <asm/uv/bios.h> | |
27 | #include <asm/uv/uv.h> | |
1400b3fa DS |
28 | #include <asm/apic.h> |
29 | #include <asm/cpu.h> | |
5ab5ab34 DS |
30 | |
31 | #define RTC_NAME "sgi_rtc" | |
32 | ||
c5428e95 | 33 | static cycle_t uv_read_rtc(struct clocksource *cs); |
5ab5ab34 | 34 | static int uv_rtc_next_event(unsigned long, struct clock_event_device *); |
ca53d434 | 35 | static int uv_rtc_shutdown(struct clock_event_device *evt); |
5ab5ab34 DS |
36 | |
37 | static struct clocksource clocksource_uv = { | |
38 | .name = RTC_NAME, | |
b0deca2e | 39 | .rating = 299, |
5ab5ab34 DS |
40 | .read = uv_read_rtc, |
41 | .mask = (cycle_t)UVH_RTC_REAL_TIME_CLOCK_MASK, | |
5ab5ab34 DS |
42 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, |
43 | }; | |
44 | ||
45 | static struct clock_event_device clock_event_device_uv = { | |
ca53d434 VK |
46 | .name = RTC_NAME, |
47 | .features = CLOCK_EVT_FEAT_ONESHOT, | |
48 | .shift = 20, | |
49 | .rating = 400, | |
50 | .irq = -1, | |
51 | .set_next_event = uv_rtc_next_event, | |
52 | .set_state_shutdown = uv_rtc_shutdown, | |
53 | .event_handler = NULL, | |
5ab5ab34 DS |
54 | }; |
55 | ||
56 | static DEFINE_PER_CPU(struct clock_event_device, cpu_ced); | |
57 | ||
58 | /* There is one of these allocated per node */ | |
59 | struct uv_rtc_timer_head { | |
60 | spinlock_t lock; | |
61 | /* next cpu waiting for timer, local node relative: */ | |
62 | int next_cpu; | |
63 | /* number of cpus on this node: */ | |
64 | int ncpus; | |
65 | struct { | |
66 | int lcpu; /* systemwide logical cpu number */ | |
67 | u64 expires; /* next timer expiration for this cpu */ | |
68 | } cpu[1]; | |
69 | }; | |
70 | ||
71 | /* | |
72 | * Access to uv_rtc_timer_head via blade id. | |
73 | */ | |
74 | static struct uv_rtc_timer_head **blade_info __read_mostly; | |
75 | ||
8c28de4d | 76 | static int uv_rtc_evt_enable; |
5ab5ab34 DS |
77 | |
78 | /* | |
79 | * Hardware interface routines | |
80 | */ | |
81 | ||
82 | /* Send IPIs to another node */ | |
83 | static void uv_rtc_send_IPI(int cpu) | |
84 | { | |
85 | unsigned long apicid, val; | |
86 | int pnode; | |
87 | ||
1400b3fa | 88 | apicid = cpu_physical_id(cpu); |
5ab5ab34 | 89 | pnode = uv_apicid_to_pnode(apicid); |
8191c9f6 | 90 | apicid |= uv_apicid_hibits; |
5ab5ab34 DS |
91 | val = (1UL << UVH_IPI_INT_SEND_SHFT) | |
92 | (apicid << UVH_IPI_INT_APIC_ID_SHFT) | | |
4a4de9c7 | 93 | (X86_PLATFORM_IPI_VECTOR << UVH_IPI_INT_VECTOR_SHFT); |
5ab5ab34 DS |
94 | |
95 | uv_write_global_mmr64(pnode, UVH_IPI_INT, val); | |
96 | } | |
97 | ||
98 | /* Check for an RTC interrupt pending */ | |
99 | static int uv_intr_pending(int pnode) | |
100 | { | |
2a919596 JS |
101 | if (is_uv1_hub()) |
102 | return uv_read_global_mmr64(pnode, UVH_EVENT_OCCURRED0) & | |
103 | UV1H_EVENT_OCCURRED0_RTC1_MASK; | |
0af63520 MT |
104 | else if (is_uvx_hub()) |
105 | return uv_read_global_mmr64(pnode, UVXH_EVENT_OCCURRED2) & | |
106 | UVXH_EVENT_OCCURRED2_RTC_1_MASK; | |
107 | return 0; | |
5ab5ab34 DS |
108 | } |
109 | ||
110 | /* Setup interrupt and return non-zero if early expiration occurred. */ | |
111 | static int uv_setup_intr(int cpu, u64 expires) | |
112 | { | |
113 | u64 val; | |
8191c9f6 | 114 | unsigned long apicid = cpu_physical_id(cpu) | uv_apicid_hibits; |
5ab5ab34 DS |
115 | int pnode = uv_cpu_to_pnode(cpu); |
116 | ||
117 | uv_write_global_mmr64(pnode, UVH_RTC1_INT_CONFIG, | |
118 | UVH_RTC1_INT_CONFIG_M_MASK); | |
119 | uv_write_global_mmr64(pnode, UVH_INT_CMPB, -1L); | |
120 | ||
2a919596 JS |
121 | if (is_uv1_hub()) |
122 | uv_write_global_mmr64(pnode, UVH_EVENT_OCCURRED0_ALIAS, | |
123 | UV1H_EVENT_OCCURRED0_RTC1_MASK); | |
124 | else | |
0af63520 MT |
125 | uv_write_global_mmr64(pnode, UVXH_EVENT_OCCURRED2_ALIAS, |
126 | UVXH_EVENT_OCCURRED2_RTC_1_MASK); | |
5ab5ab34 | 127 | |
4a4de9c7 | 128 | val = (X86_PLATFORM_IPI_VECTOR << UVH_RTC1_INT_CONFIG_VECTOR_SHFT) | |
8191c9f6 | 129 | ((u64)apicid << UVH_RTC1_INT_CONFIG_APIC_ID_SHFT); |
5ab5ab34 DS |
130 | |
131 | /* Set configuration */ | |
132 | uv_write_global_mmr64(pnode, UVH_RTC1_INT_CONFIG, val); | |
133 | /* Initialize comparator value */ | |
134 | uv_write_global_mmr64(pnode, UVH_INT_CMPB, expires); | |
135 | ||
e47938b1 DS |
136 | if (uv_read_rtc(NULL) <= expires) |
137 | return 0; | |
138 | ||
139 | return !uv_intr_pending(pnode); | |
5ab5ab34 DS |
140 | } |
141 | ||
142 | /* | |
143 | * Per-cpu timer tracking routines | |
144 | */ | |
145 | ||
146 | static __init void uv_rtc_deallocate_timers(void) | |
147 | { | |
148 | int bid; | |
149 | ||
150 | for_each_possible_blade(bid) { | |
151 | kfree(blade_info[bid]); | |
152 | } | |
153 | kfree(blade_info); | |
154 | } | |
155 | ||
156 | /* Allocate per-node list of cpu timer expiration times. */ | |
157 | static __init int uv_rtc_allocate_timers(void) | |
158 | { | |
159 | int cpu; | |
160 | ||
e87b686b | 161 | blade_info = kzalloc(uv_possible_blades * sizeof(void *), GFP_KERNEL); |
5ab5ab34 DS |
162 | if (!blade_info) |
163 | return -ENOMEM; | |
5ab5ab34 DS |
164 | |
165 | for_each_present_cpu(cpu) { | |
166 | int nid = cpu_to_node(cpu); | |
167 | int bid = uv_cpu_to_blade_id(cpu); | |
168 | int bcpu = uv_cpu_hub_info(cpu)->blade_processor_id; | |
169 | struct uv_rtc_timer_head *head = blade_info[bid]; | |
170 | ||
171 | if (!head) { | |
172 | head = kmalloc_node(sizeof(struct uv_rtc_timer_head) + | |
173 | (uv_blade_nr_possible_cpus(bid) * | |
174 | 2 * sizeof(u64)), | |
175 | GFP_KERNEL, nid); | |
176 | if (!head) { | |
177 | uv_rtc_deallocate_timers(); | |
178 | return -ENOMEM; | |
179 | } | |
180 | spin_lock_init(&head->lock); | |
181 | head->ncpus = uv_blade_nr_possible_cpus(bid); | |
182 | head->next_cpu = -1; | |
183 | blade_info[bid] = head; | |
184 | } | |
185 | ||
186 | head->cpu[bcpu].lcpu = cpu; | |
187 | head->cpu[bcpu].expires = ULLONG_MAX; | |
188 | } | |
189 | ||
190 | return 0; | |
191 | } | |
192 | ||
193 | /* Find and set the next expiring timer. */ | |
194 | static void uv_rtc_find_next_timer(struct uv_rtc_timer_head *head, int pnode) | |
195 | { | |
196 | u64 lowest = ULLONG_MAX; | |
197 | int c, bcpu = -1; | |
198 | ||
199 | head->next_cpu = -1; | |
200 | for (c = 0; c < head->ncpus; c++) { | |
201 | u64 exp = head->cpu[c].expires; | |
202 | if (exp < lowest) { | |
203 | bcpu = c; | |
204 | lowest = exp; | |
205 | } | |
206 | } | |
207 | if (bcpu >= 0) { | |
208 | head->next_cpu = bcpu; | |
209 | c = head->cpu[bcpu].lcpu; | |
210 | if (uv_setup_intr(c, lowest)) | |
211 | /* If we didn't set it up in time, trigger */ | |
212 | uv_rtc_send_IPI(c); | |
213 | } else { | |
214 | uv_write_global_mmr64(pnode, UVH_RTC1_INT_CONFIG, | |
215 | UVH_RTC1_INT_CONFIG_M_MASK); | |
216 | } | |
217 | } | |
218 | ||
219 | /* | |
220 | * Set expiration time for current cpu. | |
221 | * | |
222 | * Returns 1 if we missed the expiration time. | |
223 | */ | |
224 | static int uv_rtc_set_timer(int cpu, u64 expires) | |
225 | { | |
226 | int pnode = uv_cpu_to_pnode(cpu); | |
227 | int bid = uv_cpu_to_blade_id(cpu); | |
228 | struct uv_rtc_timer_head *head = blade_info[bid]; | |
229 | int bcpu = uv_cpu_hub_info(cpu)->blade_processor_id; | |
230 | u64 *t = &head->cpu[bcpu].expires; | |
231 | unsigned long flags; | |
232 | int next_cpu; | |
233 | ||
234 | spin_lock_irqsave(&head->lock, flags); | |
235 | ||
236 | next_cpu = head->next_cpu; | |
237 | *t = expires; | |
e47938b1 | 238 | |
5ab5ab34 DS |
239 | /* Will this one be next to go off? */ |
240 | if (next_cpu < 0 || bcpu == next_cpu || | |
241 | expires < head->cpu[next_cpu].expires) { | |
242 | head->next_cpu = bcpu; | |
243 | if (uv_setup_intr(cpu, expires)) { | |
244 | *t = ULLONG_MAX; | |
245 | uv_rtc_find_next_timer(head, pnode); | |
246 | spin_unlock_irqrestore(&head->lock, flags); | |
e47938b1 | 247 | return -ETIME; |
5ab5ab34 DS |
248 | } |
249 | } | |
250 | ||
251 | spin_unlock_irqrestore(&head->lock, flags); | |
252 | return 0; | |
253 | } | |
254 | ||
255 | /* | |
256 | * Unset expiration time for current cpu. | |
257 | * | |
258 | * Returns 1 if this timer was pending. | |
259 | */ | |
e47938b1 | 260 | static int uv_rtc_unset_timer(int cpu, int force) |
5ab5ab34 DS |
261 | { |
262 | int pnode = uv_cpu_to_pnode(cpu); | |
263 | int bid = uv_cpu_to_blade_id(cpu); | |
264 | struct uv_rtc_timer_head *head = blade_info[bid]; | |
265 | int bcpu = uv_cpu_hub_info(cpu)->blade_processor_id; | |
266 | u64 *t = &head->cpu[bcpu].expires; | |
267 | unsigned long flags; | |
268 | int rc = 0; | |
269 | ||
270 | spin_lock_irqsave(&head->lock, flags); | |
271 | ||
e47938b1 | 272 | if ((head->next_cpu == bcpu && uv_read_rtc(NULL) >= *t) || force) |
5ab5ab34 DS |
273 | rc = 1; |
274 | ||
e47938b1 DS |
275 | if (rc) { |
276 | *t = ULLONG_MAX; | |
277 | /* Was the hardware setup for this timer? */ | |
278 | if (head->next_cpu == bcpu) | |
279 | uv_rtc_find_next_timer(head, pnode); | |
280 | } | |
5ab5ab34 DS |
281 | |
282 | spin_unlock_irqrestore(&head->lock, flags); | |
283 | ||
284 | return rc; | |
285 | } | |
286 | ||
287 | ||
288 | /* | |
289 | * Kernel interface routines. | |
290 | */ | |
291 | ||
292 | /* | |
293 | * Read the RTC. | |
aca3bb59 DS |
294 | * |
295 | * Starting with HUB rev 2.0, the UV RTC register is replicated across all | |
296 | * cachelines of it's own page. This allows faster simultaneous reads | |
297 | * from a given socket. | |
5ab5ab34 | 298 | */ |
c5428e95 | 299 | static cycle_t uv_read_rtc(struct clocksource *cs) |
5ab5ab34 | 300 | { |
aca3bb59 DS |
301 | unsigned long offset; |
302 | ||
303 | if (uv_get_min_hub_revision_id() == 1) | |
304 | offset = 0; | |
305 | else | |
306 | offset = (uv_blade_processor_id() * L1_CACHE_BYTES) % PAGE_SIZE; | |
307 | ||
308 | return (cycle_t)uv_read_local_mmr(UVH_RTC | offset); | |
5ab5ab34 DS |
309 | } |
310 | ||
311 | /* | |
312 | * Program the next event, relative to now | |
313 | */ | |
314 | static int uv_rtc_next_event(unsigned long delta, | |
315 | struct clock_event_device *ced) | |
316 | { | |
317 | int ced_cpu = cpumask_first(ced->cpumask); | |
318 | ||
c5428e95 | 319 | return uv_rtc_set_timer(ced_cpu, delta + uv_read_rtc(NULL)); |
5ab5ab34 DS |
320 | } |
321 | ||
322 | /* | |
ca53d434 | 323 | * Shutdown the RTC timer |
5ab5ab34 | 324 | */ |
ca53d434 | 325 | static int uv_rtc_shutdown(struct clock_event_device *evt) |
5ab5ab34 DS |
326 | { |
327 | int ced_cpu = cpumask_first(evt->cpumask); | |
328 | ||
ca53d434 VK |
329 | uv_rtc_unset_timer(ced_cpu, 1); |
330 | return 0; | |
5ab5ab34 DS |
331 | } |
332 | ||
333 | static void uv_rtc_interrupt(void) | |
334 | { | |
5ab5ab34 | 335 | int cpu = smp_processor_id(); |
e47938b1 | 336 | struct clock_event_device *ced = &per_cpu(cpu_ced, cpu); |
5ab5ab34 DS |
337 | |
338 | if (!ced || !ced->event_handler) | |
339 | return; | |
340 | ||
e47938b1 | 341 | if (uv_rtc_unset_timer(cpu, 0) != 1) |
5ab5ab34 DS |
342 | return; |
343 | ||
344 | ced->event_handler(ced); | |
345 | } | |
346 | ||
8c28de4d DS |
347 | static int __init uv_enable_evt_rtc(char *str) |
348 | { | |
349 | uv_rtc_evt_enable = 1; | |
350 | ||
351 | return 1; | |
352 | } | |
353 | __setup("uvrtcevt", uv_enable_evt_rtc); | |
354 | ||
5ab5ab34 DS |
355 | static __init void uv_rtc_register_clockevents(struct work_struct *dummy) |
356 | { | |
89cbc767 | 357 | struct clock_event_device *ced = this_cpu_ptr(&cpu_ced); |
5ab5ab34 DS |
358 | |
359 | *ced = clock_event_device_uv; | |
360 | ced->cpumask = cpumask_of(smp_processor_id()); | |
361 | clockevents_register_device(ced); | |
362 | } | |
363 | ||
364 | static __init int uv_rtc_setup_clock(void) | |
365 | { | |
366 | int rc; | |
367 | ||
581f202b | 368 | if (!is_uv_system()) |
5ab5ab34 DS |
369 | return -ENODEV; |
370 | ||
b01cc1b0 | 371 | rc = clocksource_register_hz(&clocksource_uv, sn_rtc_cycles_per_second); |
8c28de4d DS |
372 | if (rc) |
373 | printk(KERN_INFO "UV RTC clocksource failed rc %d\n", rc); | |
374 | else | |
375 | printk(KERN_INFO "UV RTC clocksource registered freq %lu MHz\n", | |
376 | sn_rtc_cycles_per_second/(unsigned long)1E6); | |
377 | ||
581f202b | 378 | if (rc || !uv_rtc_evt_enable || x86_platform_ipi_callback) |
5ab5ab34 | 379 | return rc; |
8c28de4d | 380 | |
5ab5ab34 DS |
381 | /* Setup and register clockevents */ |
382 | rc = uv_rtc_allocate_timers(); | |
d5991ff2 DS |
383 | if (rc) |
384 | goto error; | |
385 | ||
4a4de9c7 | 386 | x86_platform_ipi_callback = uv_rtc_interrupt; |
5ab5ab34 DS |
387 | |
388 | clock_event_device_uv.mult = div_sc(sn_rtc_cycles_per_second, | |
389 | NSEC_PER_SEC, clock_event_device_uv.shift); | |
390 | ||
391 | clock_event_device_uv.min_delta_ns = NSEC_PER_SEC / | |
392 | sn_rtc_cycles_per_second; | |
393 | ||
394 | clock_event_device_uv.max_delta_ns = clocksource_uv.mask * | |
395 | (NSEC_PER_SEC / sn_rtc_cycles_per_second); | |
396 | ||
397 | rc = schedule_on_each_cpu(uv_rtc_register_clockevents); | |
398 | if (rc) { | |
4a4de9c7 | 399 | x86_platform_ipi_callback = NULL; |
5ab5ab34 | 400 | uv_rtc_deallocate_timers(); |
d5991ff2 | 401 | goto error; |
5ab5ab34 DS |
402 | } |
403 | ||
d5991ff2 DS |
404 | printk(KERN_INFO "UV RTC clockevents registered\n"); |
405 | ||
406 | return 0; | |
407 | ||
408 | error: | |
409 | clocksource_unregister(&clocksource_uv); | |
410 | printk(KERN_INFO "UV RTC clockevents failed rc %d\n", rc); | |
411 | ||
5ab5ab34 DS |
412 | return rc; |
413 | } | |
414 | arch_initcall(uv_rtc_setup_clock); |