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[linux-2.6-microblaze.git] / drivers / hv / hv.c
1 /*
2  * Copyright (c) 2009, Microsoft Corporation.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  *
13  * You should have received a copy of the GNU General Public License along with
14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
15  * Place - Suite 330, Boston, MA 02111-1307 USA.
16  *
17  * Authors:
18  *   Haiyang Zhang <haiyangz@microsoft.com>
19  *   Hank Janssen  <hjanssen@microsoft.com>
20  *
21  */
22 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
23
24 #include <linux/kernel.h>
25 #include <linux/mm.h>
26 #include <linux/slab.h>
27 #include <linux/vmalloc.h>
28 #include <linux/hyperv.h>
29 #include <linux/version.h>
30 #include <linux/interrupt.h>
31 #include <linux/clockchips.h>
32 #include <asm/hyperv.h>
33 #include <asm/mshyperv.h>
34 #include "hyperv_vmbus.h"
35
36 /* The one and only */
37 struct hv_context hv_context = {
38         .synic_initialized      = false,
39         .hypercall_page         = NULL,
40 };
41
42 #define HV_TIMER_FREQUENCY (10 * 1000 * 1000) /* 100ns period */
43 #define HV_MAX_MAX_DELTA_TICKS 0xffffffff
44 #define HV_MIN_DELTA_TICKS 1
45
46 /*
47  * query_hypervisor_info - Get version info of the windows hypervisor
48  */
49 unsigned int host_info_eax;
50 unsigned int host_info_ebx;
51 unsigned int host_info_ecx;
52 unsigned int host_info_edx;
53
54 static int query_hypervisor_info(void)
55 {
56         unsigned int eax;
57         unsigned int ebx;
58         unsigned int ecx;
59         unsigned int edx;
60         unsigned int max_leaf;
61         unsigned int op;
62
63         /*
64         * Its assumed that this is called after confirming that Viridian
65         * is present. Query id and revision.
66         */
67         eax = 0;
68         ebx = 0;
69         ecx = 0;
70         edx = 0;
71         op = HVCPUID_VENDOR_MAXFUNCTION;
72         cpuid(op, &eax, &ebx, &ecx, &edx);
73
74         max_leaf = eax;
75
76         if (max_leaf >= HVCPUID_VERSION) {
77                 eax = 0;
78                 ebx = 0;
79                 ecx = 0;
80                 edx = 0;
81                 op = HVCPUID_VERSION;
82                 cpuid(op, &eax, &ebx, &ecx, &edx);
83                 host_info_eax = eax;
84                 host_info_ebx = ebx;
85                 host_info_ecx = ecx;
86                 host_info_edx = edx;
87         }
88         return max_leaf;
89 }
90
91 /*
92  * hv_do_hypercall- Invoke the specified hypercall
93  */
94 u64 hv_do_hypercall(u64 control, void *input, void *output)
95 {
96         u64 input_address = (input) ? virt_to_phys(input) : 0;
97         u64 output_address = (output) ? virt_to_phys(output) : 0;
98         void *hypercall_page = hv_context.hypercall_page;
99 #ifdef CONFIG_X86_64
100         u64 hv_status = 0;
101
102         if (!hypercall_page)
103                 return (u64)ULLONG_MAX;
104
105         __asm__ __volatile__("mov %0, %%r8" : : "r" (output_address) : "r8");
106         __asm__ __volatile__("call *%3" : "=a" (hv_status) :
107                              "c" (control), "d" (input_address),
108                              "m" (hypercall_page));
109
110         return hv_status;
111
112 #else
113
114         u32 control_hi = control >> 32;
115         u32 control_lo = control & 0xFFFFFFFF;
116         u32 hv_status_hi = 1;
117         u32 hv_status_lo = 1;
118         u32 input_address_hi = input_address >> 32;
119         u32 input_address_lo = input_address & 0xFFFFFFFF;
120         u32 output_address_hi = output_address >> 32;
121         u32 output_address_lo = output_address & 0xFFFFFFFF;
122
123         if (!hypercall_page)
124                 return (u64)ULLONG_MAX;
125
126         __asm__ __volatile__ ("call *%8" : "=d"(hv_status_hi),
127                               "=a"(hv_status_lo) : "d" (control_hi),
128                               "a" (control_lo), "b" (input_address_hi),
129                               "c" (input_address_lo), "D"(output_address_hi),
130                               "S"(output_address_lo), "m" (hypercall_page));
131
132         return hv_status_lo | ((u64)hv_status_hi << 32);
133 #endif /* !x86_64 */
134 }
135 EXPORT_SYMBOL_GPL(hv_do_hypercall);
136
137 #ifdef CONFIG_X86_64
138 static cycle_t read_hv_clock_tsc(struct clocksource *arg)
139 {
140         cycle_t current_tick;
141         struct ms_hyperv_tsc_page *tsc_pg = hv_context.tsc_page;
142
143         if (tsc_pg->tsc_sequence != 0) {
144                 /*
145                  * Use the tsc page to compute the value.
146                  */
147
148                 while (1) {
149                         cycle_t tmp;
150                         u32 sequence = tsc_pg->tsc_sequence;
151                         u64 cur_tsc;
152                         u64 scale = tsc_pg->tsc_scale;
153                         s64 offset = tsc_pg->tsc_offset;
154
155                         rdtscll(cur_tsc);
156                         /* current_tick = ((cur_tsc *scale) >> 64) + offset */
157                         asm("mulq %3"
158                                 : "=d" (current_tick), "=a" (tmp)
159                                 : "a" (cur_tsc), "r" (scale));
160
161                         current_tick += offset;
162                         if (tsc_pg->tsc_sequence == sequence)
163                                 return current_tick;
164
165                         if (tsc_pg->tsc_sequence != 0)
166                                 continue;
167                         /*
168                          * Fallback using MSR method.
169                          */
170                         break;
171                 }
172         }
173         rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
174         return current_tick;
175 }
176
177 static struct clocksource hyperv_cs_tsc = {
178                 .name           = "hyperv_clocksource_tsc_page",
179                 .rating         = 425,
180                 .read           = read_hv_clock_tsc,
181                 .mask           = CLOCKSOURCE_MASK(64),
182                 .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
183 };
184 #endif
185
186
187 /*
188  * hv_init - Main initialization routine.
189  *
190  * This routine must be called before any other routines in here are called
191  */
192 int hv_init(void)
193 {
194         int max_leaf;
195         union hv_x64_msr_hypercall_contents hypercall_msr;
196         void *virtaddr = NULL;
197
198         memset(hv_context.synic_event_page, 0, sizeof(void *) * NR_CPUS);
199         memset(hv_context.synic_message_page, 0,
200                sizeof(void *) * NR_CPUS);
201         memset(hv_context.post_msg_page, 0,
202                sizeof(void *) * NR_CPUS);
203         memset(hv_context.vp_index, 0,
204                sizeof(int) * NR_CPUS);
205         memset(hv_context.event_dpc, 0,
206                sizeof(void *) * NR_CPUS);
207         memset(hv_context.msg_dpc, 0,
208                sizeof(void *) * NR_CPUS);
209         memset(hv_context.clk_evt, 0,
210                sizeof(void *) * NR_CPUS);
211
212         max_leaf = query_hypervisor_info();
213
214         /*
215          * Write our OS ID.
216          */
217         hv_context.guestid = generate_guest_id(0, LINUX_VERSION_CODE, 0);
218         wrmsrl(HV_X64_MSR_GUEST_OS_ID, hv_context.guestid);
219
220         /* See if the hypercall page is already set */
221         rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
222
223         virtaddr = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL_EXEC);
224
225         if (!virtaddr)
226                 goto cleanup;
227
228         hypercall_msr.enable = 1;
229
230         hypercall_msr.guest_physical_address = vmalloc_to_pfn(virtaddr);
231         wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
232
233         /* Confirm that hypercall page did get setup. */
234         hypercall_msr.as_uint64 = 0;
235         rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
236
237         if (!hypercall_msr.enable)
238                 goto cleanup;
239
240         hv_context.hypercall_page = virtaddr;
241
242 #ifdef CONFIG_X86_64
243         if (ms_hyperv.features & HV_X64_MSR_REFERENCE_TSC_AVAILABLE) {
244                 union hv_x64_msr_hypercall_contents tsc_msr;
245                 void *va_tsc;
246
247                 va_tsc = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL);
248                 if (!va_tsc)
249                         goto cleanup;
250                 hv_context.tsc_page = va_tsc;
251
252                 rdmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
253
254                 tsc_msr.enable = 1;
255                 tsc_msr.guest_physical_address = vmalloc_to_pfn(va_tsc);
256
257                 wrmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
258                 clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100);
259         }
260 #endif
261         return 0;
262
263 cleanup:
264         if (virtaddr) {
265                 if (hypercall_msr.enable) {
266                         hypercall_msr.as_uint64 = 0;
267                         wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
268                 }
269
270                 vfree(virtaddr);
271         }
272
273         return -ENOTSUPP;
274 }
275
276 /*
277  * hv_cleanup - Cleanup routine.
278  *
279  * This routine is called normally during driver unloading or exiting.
280  */
281 void hv_cleanup(void)
282 {
283         union hv_x64_msr_hypercall_contents hypercall_msr;
284
285         /* Reset our OS id */
286         wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
287
288         if (hv_context.hypercall_page) {
289                 hypercall_msr.as_uint64 = 0;
290                 wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
291                 vfree(hv_context.hypercall_page);
292                 hv_context.hypercall_page = NULL;
293         }
294
295 #ifdef CONFIG_X86_64
296         /*
297          * Cleanup the TSC page based CS.
298          */
299         if (ms_hyperv.features & HV_X64_MSR_REFERENCE_TSC_AVAILABLE) {
300                 /*
301                  * Crash can happen in an interrupt context and unregistering
302                  * a clocksource is impossible and redundant in this case.
303                  */
304                 if (!oops_in_progress) {
305                         clocksource_change_rating(&hyperv_cs_tsc, 10);
306                         clocksource_unregister(&hyperv_cs_tsc);
307                 }
308
309                 hypercall_msr.as_uint64 = 0;
310                 wrmsrl(HV_X64_MSR_REFERENCE_TSC, hypercall_msr.as_uint64);
311                 vfree(hv_context.tsc_page);
312                 hv_context.tsc_page = NULL;
313         }
314 #endif
315 }
316
317 /*
318  * hv_post_message - Post a message using the hypervisor message IPC.
319  *
320  * This involves a hypercall.
321  */
322 int hv_post_message(union hv_connection_id connection_id,
323                   enum hv_message_type message_type,
324                   void *payload, size_t payload_size)
325 {
326
327         struct hv_input_post_message *aligned_msg;
328         u64 status;
329
330         if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
331                 return -EMSGSIZE;
332
333         aligned_msg = (struct hv_input_post_message *)
334                         hv_context.post_msg_page[get_cpu()];
335
336         aligned_msg->connectionid = connection_id;
337         aligned_msg->reserved = 0;
338         aligned_msg->message_type = message_type;
339         aligned_msg->payload_size = payload_size;
340         memcpy((void *)aligned_msg->payload, payload, payload_size);
341
342         status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL);
343
344         put_cpu();
345         return status & 0xFFFF;
346 }
347
348 static int hv_ce_set_next_event(unsigned long delta,
349                                 struct clock_event_device *evt)
350 {
351         cycle_t current_tick;
352
353         WARN_ON(!clockevent_state_oneshot(evt));
354
355         rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
356         current_tick += delta;
357         wrmsrl(HV_X64_MSR_STIMER0_COUNT, current_tick);
358         return 0;
359 }
360
361 static int hv_ce_shutdown(struct clock_event_device *evt)
362 {
363         wrmsrl(HV_X64_MSR_STIMER0_COUNT, 0);
364         wrmsrl(HV_X64_MSR_STIMER0_CONFIG, 0);
365
366         return 0;
367 }
368
369 static int hv_ce_set_oneshot(struct clock_event_device *evt)
370 {
371         union hv_timer_config timer_cfg;
372
373         timer_cfg.enable = 1;
374         timer_cfg.auto_enable = 1;
375         timer_cfg.sintx = VMBUS_MESSAGE_SINT;
376         wrmsrl(HV_X64_MSR_STIMER0_CONFIG, timer_cfg.as_uint64);
377
378         return 0;
379 }
380
381 static void hv_init_clockevent_device(struct clock_event_device *dev, int cpu)
382 {
383         dev->name = "Hyper-V clockevent";
384         dev->features = CLOCK_EVT_FEAT_ONESHOT;
385         dev->cpumask = cpumask_of(cpu);
386         dev->rating = 1000;
387         /*
388          * Avoid settint dev->owner = THIS_MODULE deliberately as doing so will
389          * result in clockevents_config_and_register() taking additional
390          * references to the hv_vmbus module making it impossible to unload.
391          */
392
393         dev->set_state_shutdown = hv_ce_shutdown;
394         dev->set_state_oneshot = hv_ce_set_oneshot;
395         dev->set_next_event = hv_ce_set_next_event;
396 }
397
398
399 int hv_synic_alloc(void)
400 {
401         size_t size = sizeof(struct tasklet_struct);
402         size_t ced_size = sizeof(struct clock_event_device);
403         int cpu;
404
405         hv_context.hv_numa_map = kzalloc(sizeof(struct cpumask) * nr_node_ids,
406                                          GFP_ATOMIC);
407         if (hv_context.hv_numa_map == NULL) {
408                 pr_err("Unable to allocate NUMA map\n");
409                 goto err;
410         }
411
412         for_each_online_cpu(cpu) {
413                 hv_context.event_dpc[cpu] = kmalloc(size, GFP_ATOMIC);
414                 if (hv_context.event_dpc[cpu] == NULL) {
415                         pr_err("Unable to allocate event dpc\n");
416                         goto err;
417                 }
418                 tasklet_init(hv_context.event_dpc[cpu], vmbus_on_event, cpu);
419
420                 hv_context.msg_dpc[cpu] = kmalloc(size, GFP_ATOMIC);
421                 if (hv_context.msg_dpc[cpu] == NULL) {
422                         pr_err("Unable to allocate event dpc\n");
423                         goto err;
424                 }
425                 tasklet_init(hv_context.msg_dpc[cpu], vmbus_on_msg_dpc, cpu);
426
427                 hv_context.clk_evt[cpu] = kzalloc(ced_size, GFP_ATOMIC);
428                 if (hv_context.clk_evt[cpu] == NULL) {
429                         pr_err("Unable to allocate clock event device\n");
430                         goto err;
431                 }
432
433                 hv_init_clockevent_device(hv_context.clk_evt[cpu], cpu);
434
435                 hv_context.synic_message_page[cpu] =
436                         (void *)get_zeroed_page(GFP_ATOMIC);
437
438                 if (hv_context.synic_message_page[cpu] == NULL) {
439                         pr_err("Unable to allocate SYNIC message page\n");
440                         goto err;
441                 }
442
443                 hv_context.synic_event_page[cpu] =
444                         (void *)get_zeroed_page(GFP_ATOMIC);
445
446                 if (hv_context.synic_event_page[cpu] == NULL) {
447                         pr_err("Unable to allocate SYNIC event page\n");
448                         goto err;
449                 }
450
451                 hv_context.post_msg_page[cpu] =
452                         (void *)get_zeroed_page(GFP_ATOMIC);
453
454                 if (hv_context.post_msg_page[cpu] == NULL) {
455                         pr_err("Unable to allocate post msg page\n");
456                         goto err;
457                 }
458         }
459
460         return 0;
461 err:
462         return -ENOMEM;
463 }
464
465 static void hv_synic_free_cpu(int cpu)
466 {
467         kfree(hv_context.event_dpc[cpu]);
468         kfree(hv_context.msg_dpc[cpu]);
469         kfree(hv_context.clk_evt[cpu]);
470         if (hv_context.synic_event_page[cpu])
471                 free_page((unsigned long)hv_context.synic_event_page[cpu]);
472         if (hv_context.synic_message_page[cpu])
473                 free_page((unsigned long)hv_context.synic_message_page[cpu]);
474         if (hv_context.post_msg_page[cpu])
475                 free_page((unsigned long)hv_context.post_msg_page[cpu]);
476 }
477
478 void hv_synic_free(void)
479 {
480         int cpu;
481
482         kfree(hv_context.hv_numa_map);
483         for_each_online_cpu(cpu)
484                 hv_synic_free_cpu(cpu);
485 }
486
487 /*
488  * hv_synic_init - Initialize the Synthethic Interrupt Controller.
489  *
490  * If it is already initialized by another entity (ie x2v shim), we need to
491  * retrieve the initialized message and event pages.  Otherwise, we create and
492  * initialize the message and event pages.
493  */
494 void hv_synic_init(void *arg)
495 {
496         u64 version;
497         union hv_synic_simp simp;
498         union hv_synic_siefp siefp;
499         union hv_synic_sint shared_sint;
500         union hv_synic_scontrol sctrl;
501         u64 vp_index;
502
503         int cpu = smp_processor_id();
504
505         if (!hv_context.hypercall_page)
506                 return;
507
508         /* Check the version */
509         rdmsrl(HV_X64_MSR_SVERSION, version);
510
511         /* Setup the Synic's message page */
512         rdmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
513         simp.simp_enabled = 1;
514         simp.base_simp_gpa = virt_to_phys(hv_context.synic_message_page[cpu])
515                 >> PAGE_SHIFT;
516
517         wrmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
518
519         /* Setup the Synic's event page */
520         rdmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
521         siefp.siefp_enabled = 1;
522         siefp.base_siefp_gpa = virt_to_phys(hv_context.synic_event_page[cpu])
523                 >> PAGE_SHIFT;
524
525         wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
526
527         /* Setup the shared SINT. */
528         rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
529
530         shared_sint.as_uint64 = 0;
531         shared_sint.vector = HYPERVISOR_CALLBACK_VECTOR;
532         shared_sint.masked = false;
533         shared_sint.auto_eoi = true;
534
535         wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
536
537         /* Enable the global synic bit */
538         rdmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
539         sctrl.enable = 1;
540
541         wrmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
542
543         hv_context.synic_initialized = true;
544
545         /*
546          * Setup the mapping between Hyper-V's notion
547          * of cpuid and Linux' notion of cpuid.
548          * This array will be indexed using Linux cpuid.
549          */
550         rdmsrl(HV_X64_MSR_VP_INDEX, vp_index);
551         hv_context.vp_index[cpu] = (u32)vp_index;
552
553         INIT_LIST_HEAD(&hv_context.percpu_list[cpu]);
554
555         /*
556          * Register the per-cpu clockevent source.
557          */
558         if (ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE)
559                 clockevents_config_and_register(hv_context.clk_evt[cpu],
560                                                 HV_TIMER_FREQUENCY,
561                                                 HV_MIN_DELTA_TICKS,
562                                                 HV_MAX_MAX_DELTA_TICKS);
563         return;
564 }
565
566 /*
567  * hv_synic_clockevents_cleanup - Cleanup clockevent devices
568  */
569 void hv_synic_clockevents_cleanup(void)
570 {
571         int cpu;
572
573         if (!(ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE))
574                 return;
575
576         for_each_online_cpu(cpu)
577                 clockevents_unbind_device(hv_context.clk_evt[cpu], cpu);
578 }
579
580 /*
581  * hv_synic_cleanup - Cleanup routine for hv_synic_init().
582  */
583 void hv_synic_cleanup(void *arg)
584 {
585         union hv_synic_sint shared_sint;
586         union hv_synic_simp simp;
587         union hv_synic_siefp siefp;
588         union hv_synic_scontrol sctrl;
589         int cpu = smp_processor_id();
590
591         if (!hv_context.synic_initialized)
592                 return;
593
594         /* Turn off clockevent device */
595         if (ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE)
596                 hv_ce_shutdown(hv_context.clk_evt[cpu]);
597
598         rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
599
600         shared_sint.masked = 1;
601
602         /* Need to correctly cleanup in the case of SMP!!! */
603         /* Disable the interrupt */
604         wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
605
606         rdmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
607         simp.simp_enabled = 0;
608         simp.base_simp_gpa = 0;
609
610         wrmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
611
612         rdmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
613         siefp.siefp_enabled = 0;
614         siefp.base_siefp_gpa = 0;
615
616         wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
617
618         /* Disable the global synic bit */
619         rdmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
620         sctrl.enable = 0;
621         wrmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
622 }