GNU Linux-libre 4.4.289-gnu1
[releases.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 <asm/nospec-branch.h>
35 #include "hyperv_vmbus.h"
36
37 /* The one and only */
38 struct hv_context hv_context = {
39         .synic_initialized      = false,
40         .hypercall_page         = NULL,
41 };
42
43 #define HV_TIMER_FREQUENCY (10 * 1000 * 1000) /* 100ns period */
44 #define HV_MAX_MAX_DELTA_TICKS 0xffffffff
45 #define HV_MIN_DELTA_TICKS 1
46
47 /*
48  * query_hypervisor_info - Get version info of the windows hypervisor
49  */
50 unsigned int host_info_eax;
51 unsigned int host_info_ebx;
52 unsigned int host_info_ecx;
53 unsigned int host_info_edx;
54
55 static int query_hypervisor_info(void)
56 {
57         unsigned int eax;
58         unsigned int ebx;
59         unsigned int ecx;
60         unsigned int edx;
61         unsigned int max_leaf;
62         unsigned int op;
63
64         /*
65         * Its assumed that this is called after confirming that Viridian
66         * is present. Query id and revision.
67         */
68         eax = 0;
69         ebx = 0;
70         ecx = 0;
71         edx = 0;
72         op = HVCPUID_VENDOR_MAXFUNCTION;
73         cpuid(op, &eax, &ebx, &ecx, &edx);
74
75         max_leaf = eax;
76
77         if (max_leaf >= HVCPUID_VERSION) {
78                 eax = 0;
79                 ebx = 0;
80                 ecx = 0;
81                 edx = 0;
82                 op = HVCPUID_VERSION;
83                 cpuid(op, &eax, &ebx, &ecx, &edx);
84                 host_info_eax = eax;
85                 host_info_ebx = ebx;
86                 host_info_ecx = ecx;
87                 host_info_edx = edx;
88         }
89         return max_leaf;
90 }
91
92 /*
93  * do_hypercall- Invoke the specified hypercall
94  */
95 static u64 do_hypercall(u64 control, void *input, void *output)
96 {
97         u64 input_address = (input) ? virt_to_phys(input) : 0;
98         u64 output_address = (output) ? virt_to_phys(output) : 0;
99         void *hypercall_page = hv_context.hypercall_page;
100 #ifdef CONFIG_X86_64
101         u64 hv_status = 0;
102
103         if (!hypercall_page)
104                 return (u64)ULLONG_MAX;
105
106         __asm__ __volatile__("mov %0, %%r8" : : "r" (output_address) : "r8");
107         __asm__ __volatile__(CALL_NOSPEC :
108                              "=a" (hv_status) :
109                              "c" (control), "d" (input_address),
110                              THUNK_TARGET(hypercall_page));
111
112         return hv_status;
113
114 #else
115
116         u32 control_hi = control >> 32;
117         u32 control_lo = control & 0xFFFFFFFF;
118         u32 hv_status_hi = 1;
119         u32 hv_status_lo = 1;
120         u32 input_address_hi = input_address >> 32;
121         u32 input_address_lo = input_address & 0xFFFFFFFF;
122         u32 output_address_hi = output_address >> 32;
123         u32 output_address_lo = output_address & 0xFFFFFFFF;
124
125         if (!hypercall_page)
126                 return (u64)ULLONG_MAX;
127
128         __asm__ __volatile__ (CALL_NOSPEC : "=d"(hv_status_hi),
129                               "=a"(hv_status_lo) : "d" (control_hi),
130                               "a" (control_lo), "b" (input_address_hi),
131                               "c" (input_address_lo), "D"(output_address_hi),
132                               "S"(output_address_lo),
133                               THUNK_TARGET(hypercall_page));
134
135         return hv_status_lo | ((u64)hv_status_hi << 32);
136 #endif /* !x86_64 */
137 }
138
139 #ifdef CONFIG_X86_64
140 static cycle_t read_hv_clock_tsc(struct clocksource *arg)
141 {
142         cycle_t current_tick;
143         struct ms_hyperv_tsc_page *tsc_pg = hv_context.tsc_page;
144
145         if (tsc_pg->tsc_sequence != -1) {
146                 /*
147                  * Use the tsc page to compute the value.
148                  */
149
150                 while (1) {
151                         cycle_t tmp;
152                         u32 sequence = tsc_pg->tsc_sequence;
153                         u64 cur_tsc;
154                         u64 scale = tsc_pg->tsc_scale;
155                         s64 offset = tsc_pg->tsc_offset;
156
157                         rdtscll(cur_tsc);
158                         /* current_tick = ((cur_tsc *scale) >> 64) + offset */
159                         asm("mulq %3"
160                                 : "=d" (current_tick), "=a" (tmp)
161                                 : "a" (cur_tsc), "r" (scale));
162
163                         current_tick += offset;
164                         if (tsc_pg->tsc_sequence == sequence)
165                                 return current_tick;
166
167                         if (tsc_pg->tsc_sequence != -1)
168                                 continue;
169                         /*
170                          * Fallback using MSR method.
171                          */
172                         break;
173                 }
174         }
175         rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
176         return current_tick;
177 }
178
179 static struct clocksource hyperv_cs_tsc = {
180                 .name           = "hyperv_clocksource_tsc_page",
181                 .rating         = 425,
182                 .read           = read_hv_clock_tsc,
183                 .mask           = CLOCKSOURCE_MASK(64),
184                 .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
185 };
186 #endif
187
188
189 /*
190  * hv_init - Main initialization routine.
191  *
192  * This routine must be called before any other routines in here are called
193  */
194 int hv_init(void)
195 {
196         int max_leaf;
197         union hv_x64_msr_hypercall_contents hypercall_msr;
198         void *virtaddr = NULL;
199
200         memset(hv_context.synic_event_page, 0, sizeof(void *) * NR_CPUS);
201         memset(hv_context.synic_message_page, 0,
202                sizeof(void *) * NR_CPUS);
203         memset(hv_context.post_msg_page, 0,
204                sizeof(void *) * NR_CPUS);
205         memset(hv_context.vp_index, 0,
206                sizeof(int) * NR_CPUS);
207         memset(hv_context.event_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_RX);
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(bool crash)
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                 if (!crash)
292                         vfree(hv_context.hypercall_page);
293                 hv_context.hypercall_page = NULL;
294         }
295
296 #ifdef CONFIG_X86_64
297         /*
298          * Cleanup the TSC page based CS.
299          */
300         if (ms_hyperv.features & HV_X64_MSR_REFERENCE_TSC_AVAILABLE) {
301                 /*
302                  * Crash can happen in an interrupt context and unregistering
303                  * a clocksource is impossible and redundant in this case.
304                  */
305                 if (!oops_in_progress) {
306                         clocksource_change_rating(&hyperv_cs_tsc, 10);
307                         clocksource_unregister(&hyperv_cs_tsc);
308                 }
309
310                 hypercall_msr.as_uint64 = 0;
311                 wrmsrl(HV_X64_MSR_REFERENCE_TSC, hypercall_msr.as_uint64);
312                 if (!crash) {
313                         vfree(hv_context.tsc_page);
314                         hv_context.tsc_page = NULL;
315                 }
316         }
317 #endif
318 }
319
320 /*
321  * hv_post_message - Post a message using the hypervisor message IPC.
322  *
323  * This involves a hypercall.
324  */
325 int hv_post_message(union hv_connection_id connection_id,
326                   enum hv_message_type message_type,
327                   void *payload, size_t payload_size)
328 {
329
330         struct hv_input_post_message *aligned_msg;
331         u16 status;
332
333         if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
334                 return -EMSGSIZE;
335
336         aligned_msg = (struct hv_input_post_message *)
337                         hv_context.post_msg_page[get_cpu()];
338
339         aligned_msg->connectionid = connection_id;
340         aligned_msg->reserved = 0;
341         aligned_msg->message_type = message_type;
342         aligned_msg->payload_size = payload_size;
343         memcpy((void *)aligned_msg->payload, payload, payload_size);
344
345         status = do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL)
346                 & 0xFFFF;
347
348         put_cpu();
349         return status;
350 }
351
352
353 /*
354  * hv_signal_event -
355  * Signal an event on the specified connection using the hypervisor event IPC.
356  *
357  * This involves a hypercall.
358  */
359 u16 hv_signal_event(void *con_id)
360 {
361         u16 status;
362
363         status = (do_hypercall(HVCALL_SIGNAL_EVENT, con_id, NULL) & 0xFFFF);
364
365         return status;
366 }
367
368 static int hv_ce_set_next_event(unsigned long delta,
369                                 struct clock_event_device *evt)
370 {
371         cycle_t current_tick;
372
373         WARN_ON(!clockevent_state_oneshot(evt));
374
375         rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
376         current_tick += delta;
377         wrmsrl(HV_X64_MSR_STIMER0_COUNT, current_tick);
378         return 0;
379 }
380
381 static int hv_ce_shutdown(struct clock_event_device *evt)
382 {
383         wrmsrl(HV_X64_MSR_STIMER0_COUNT, 0);
384         wrmsrl(HV_X64_MSR_STIMER0_CONFIG, 0);
385
386         return 0;
387 }
388
389 static int hv_ce_set_oneshot(struct clock_event_device *evt)
390 {
391         union hv_timer_config timer_cfg;
392
393         timer_cfg.enable = 1;
394         timer_cfg.auto_enable = 1;
395         timer_cfg.sintx = VMBUS_MESSAGE_SINT;
396         wrmsrl(HV_X64_MSR_STIMER0_CONFIG, timer_cfg.as_uint64);
397
398         return 0;
399 }
400
401 static void hv_init_clockevent_device(struct clock_event_device *dev, int cpu)
402 {
403         dev->name = "Hyper-V clockevent";
404         dev->features = CLOCK_EVT_FEAT_ONESHOT;
405         dev->cpumask = cpumask_of(cpu);
406         dev->rating = 1000;
407         /*
408          * Avoid settint dev->owner = THIS_MODULE deliberately as doing so will
409          * result in clockevents_config_and_register() taking additional
410          * references to the hv_vmbus module making it impossible to unload.
411          */
412
413         dev->set_state_shutdown = hv_ce_shutdown;
414         dev->set_state_oneshot = hv_ce_set_oneshot;
415         dev->set_next_event = hv_ce_set_next_event;
416 }
417
418
419 int hv_synic_alloc(void)
420 {
421         size_t size = sizeof(struct tasklet_struct);
422         size_t ced_size = sizeof(struct clock_event_device);
423         int cpu;
424
425         hv_context.hv_numa_map = kzalloc(sizeof(struct cpumask) * nr_node_ids,
426                                          GFP_ATOMIC);
427         if (hv_context.hv_numa_map == NULL) {
428                 pr_err("Unable to allocate NUMA map\n");
429                 goto err;
430         }
431
432         for_each_present_cpu(cpu) {
433                 hv_context.event_dpc[cpu] = kmalloc(size, GFP_ATOMIC);
434                 if (hv_context.event_dpc[cpu] == NULL) {
435                         pr_err("Unable to allocate event dpc\n");
436                         goto err;
437                 }
438                 tasklet_init(hv_context.event_dpc[cpu], vmbus_on_event, cpu);
439
440                 hv_context.clk_evt[cpu] = kzalloc(ced_size, GFP_ATOMIC);
441                 if (hv_context.clk_evt[cpu] == NULL) {
442                         pr_err("Unable to allocate clock event device\n");
443                         goto err;
444                 }
445
446                 hv_init_clockevent_device(hv_context.clk_evt[cpu], cpu);
447
448                 hv_context.synic_message_page[cpu] =
449                         (void *)get_zeroed_page(GFP_ATOMIC);
450
451                 if (hv_context.synic_message_page[cpu] == NULL) {
452                         pr_err("Unable to allocate SYNIC message page\n");
453                         goto err;
454                 }
455
456                 hv_context.synic_event_page[cpu] =
457                         (void *)get_zeroed_page(GFP_ATOMIC);
458
459                 if (hv_context.synic_event_page[cpu] == NULL) {
460                         pr_err("Unable to allocate SYNIC event page\n");
461                         goto err;
462                 }
463
464                 hv_context.post_msg_page[cpu] =
465                         (void *)get_zeroed_page(GFP_ATOMIC);
466
467                 if (hv_context.post_msg_page[cpu] == NULL) {
468                         pr_err("Unable to allocate post msg page\n");
469                         goto err;
470                 }
471
472                 INIT_LIST_HEAD(&hv_context.percpu_list[cpu]);
473         }
474
475         return 0;
476 err:
477         return -ENOMEM;
478 }
479
480 static void hv_synic_free_cpu(int cpu)
481 {
482         kfree(hv_context.event_dpc[cpu]);
483         kfree(hv_context.clk_evt[cpu]);
484         if (hv_context.synic_event_page[cpu])
485                 free_page((unsigned long)hv_context.synic_event_page[cpu]);
486         if (hv_context.synic_message_page[cpu])
487                 free_page((unsigned long)hv_context.synic_message_page[cpu]);
488         if (hv_context.post_msg_page[cpu])
489                 free_page((unsigned long)hv_context.post_msg_page[cpu]);
490 }
491
492 void hv_synic_free(void)
493 {
494         int cpu;
495
496         kfree(hv_context.hv_numa_map);
497         for_each_present_cpu(cpu)
498                 hv_synic_free_cpu(cpu);
499 }
500
501 /*
502  * hv_synic_init - Initialize the Synthethic Interrupt Controller.
503  *
504  * If it is already initialized by another entity (ie x2v shim), we need to
505  * retrieve the initialized message and event pages.  Otherwise, we create and
506  * initialize the message and event pages.
507  */
508 void hv_synic_init(void *arg)
509 {
510         u64 version;
511         union hv_synic_simp simp;
512         union hv_synic_siefp siefp;
513         union hv_synic_sint shared_sint;
514         union hv_synic_scontrol sctrl;
515         u64 vp_index;
516
517         int cpu = smp_processor_id();
518
519         if (!hv_context.hypercall_page)
520                 return;
521
522         /* Check the version */
523         rdmsrl(HV_X64_MSR_SVERSION, version);
524
525         /* Setup the Synic's message page */
526         rdmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
527         simp.simp_enabled = 1;
528         simp.base_simp_gpa = virt_to_phys(hv_context.synic_message_page[cpu])
529                 >> PAGE_SHIFT;
530
531         wrmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
532
533         /* Setup the Synic's event page */
534         rdmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
535         siefp.siefp_enabled = 1;
536         siefp.base_siefp_gpa = virt_to_phys(hv_context.synic_event_page[cpu])
537                 >> PAGE_SHIFT;
538
539         wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
540
541         /* Setup the shared SINT. */
542         rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
543
544         shared_sint.as_uint64 = 0;
545         shared_sint.vector = HYPERVISOR_CALLBACK_VECTOR;
546         shared_sint.masked = false;
547         shared_sint.auto_eoi = true;
548
549         wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
550
551         /* Enable the global synic bit */
552         rdmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
553         sctrl.enable = 1;
554
555         wrmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
556
557         hv_context.synic_initialized = true;
558
559         /*
560          * Setup the mapping between Hyper-V's notion
561          * of cpuid and Linux' notion of cpuid.
562          * This array will be indexed using Linux cpuid.
563          */
564         rdmsrl(HV_X64_MSR_VP_INDEX, vp_index);
565         hv_context.vp_index[cpu] = (u32)vp_index;
566
567         /*
568          * Register the per-cpu clockevent source.
569          */
570         if (ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE)
571                 clockevents_config_and_register(hv_context.clk_evt[cpu],
572                                                 HV_TIMER_FREQUENCY,
573                                                 HV_MIN_DELTA_TICKS,
574                                                 HV_MAX_MAX_DELTA_TICKS);
575         return;
576 }
577
578 /*
579  * hv_synic_clockevents_cleanup - Cleanup clockevent devices
580  */
581 void hv_synic_clockevents_cleanup(void)
582 {
583         int cpu;
584
585         if (!(ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE))
586                 return;
587
588         for_each_online_cpu(cpu)
589                 clockevents_unbind_device(hv_context.clk_evt[cpu], cpu);
590 }
591
592 /*
593  * hv_synic_cleanup - Cleanup routine for hv_synic_init().
594  */
595 void hv_synic_cleanup(void *arg)
596 {
597         union hv_synic_sint shared_sint;
598         union hv_synic_simp simp;
599         union hv_synic_siefp siefp;
600         union hv_synic_scontrol sctrl;
601         int cpu = smp_processor_id();
602
603         if (!hv_context.synic_initialized)
604                 return;
605
606         /* Turn off clockevent device */
607         if (ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE)
608                 hv_ce_shutdown(hv_context.clk_evt[cpu]);
609
610         rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
611
612         shared_sint.masked = 1;
613
614         /* Need to correctly cleanup in the case of SMP!!! */
615         /* Disable the interrupt */
616         wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
617
618         rdmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
619         simp.simp_enabled = 0;
620         simp.base_simp_gpa = 0;
621
622         wrmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
623
624         rdmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
625         siefp.siefp_enabled = 0;
626         siefp.base_siefp_gpa = 0;
627
628         wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
629
630         /* Disable the global synic bit */
631         rdmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
632         sctrl.enable = 0;
633         wrmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
634 }