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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 */
37struct 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 */
49unsigned int host_info_eax;
50unsigned int host_info_ebx;
51unsigned int host_info_ecx;
52unsigned int host_info_edx;
53
54static 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 */
94u64 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}
135EXPORT_SYMBOL_GPL(hv_do_hypercall);
136
137#ifdef CONFIG_X86_64
138static 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
177static 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 */
192int 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
263cleanup:
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 */
281void 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 */
322int 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
348static 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
361static 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
369static 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
381static 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
399int 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;
461err:
462 return -ENOMEM;
463}
464
465static 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
478void 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 */
494void 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 */
569void 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 */
583void 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}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2009, Microsoft Corporation.
4 *
5 * Authors:
6 * Haiyang Zhang <haiyangz@microsoft.com>
7 * Hank Janssen <hjanssen@microsoft.com>
8 */
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/kernel.h>
12#include <linux/mm.h>
13#include <linux/slab.h>
14#include <linux/vmalloc.h>
15#include <linux/hyperv.h>
16#include <linux/random.h>
17#include <linux/clockchips.h>
18#include <linux/delay.h>
19#include <linux/interrupt.h>
20#include <clocksource/hyperv_timer.h>
21#include <asm/mshyperv.h>
22#include "hyperv_vmbus.h"
23
24/* The one and only */
25struct hv_context hv_context;
26
27/*
28 * hv_init - Main initialization routine.
29 *
30 * This routine must be called before any other routines in here are called
31 */
32int hv_init(void)
33{
34 hv_context.cpu_context = alloc_percpu(struct hv_per_cpu_context);
35 if (!hv_context.cpu_context)
36 return -ENOMEM;
37 return 0;
38}
39
40/*
41 * Functions for allocating and freeing memory with size and
42 * alignment HV_HYP_PAGE_SIZE. These functions are needed because
43 * the guest page size may not be the same as the Hyper-V page
44 * size. We depend upon kmalloc() aligning power-of-two size
45 * allocations to the allocation size boundary, so that the
46 * allocated memory appears to Hyper-V as a page of the size
47 * it expects.
48 */
49
50void *hv_alloc_hyperv_page(void)
51{
52 BUILD_BUG_ON(PAGE_SIZE < HV_HYP_PAGE_SIZE);
53
54 if (PAGE_SIZE == HV_HYP_PAGE_SIZE)
55 return (void *)__get_free_page(GFP_KERNEL);
56 else
57 return kmalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
58}
59
60void *hv_alloc_hyperv_zeroed_page(void)
61{
62 if (PAGE_SIZE == HV_HYP_PAGE_SIZE)
63 return (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
64 else
65 return kzalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
66}
67
68void hv_free_hyperv_page(unsigned long addr)
69{
70 if (PAGE_SIZE == HV_HYP_PAGE_SIZE)
71 free_page(addr);
72 else
73 kfree((void *)addr);
74}
75
76/*
77 * hv_post_message - Post a message using the hypervisor message IPC.
78 *
79 * This involves a hypercall.
80 */
81int hv_post_message(union hv_connection_id connection_id,
82 enum hv_message_type message_type,
83 void *payload, size_t payload_size)
84{
85 struct hv_input_post_message *aligned_msg;
86 struct hv_per_cpu_context *hv_cpu;
87 u64 status;
88
89 if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
90 return -EMSGSIZE;
91
92 hv_cpu = get_cpu_ptr(hv_context.cpu_context);
93 aligned_msg = hv_cpu->post_msg_page;
94 aligned_msg->connectionid = connection_id;
95 aligned_msg->reserved = 0;
96 aligned_msg->message_type = message_type;
97 aligned_msg->payload_size = payload_size;
98 memcpy((void *)aligned_msg->payload, payload, payload_size);
99
100 status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL);
101
102 /* Preemption must remain disabled until after the hypercall
103 * so some other thread can't get scheduled onto this cpu and
104 * corrupt the per-cpu post_msg_page
105 */
106 put_cpu_ptr(hv_cpu);
107
108 return hv_result(status);
109}
110
111int hv_synic_alloc(void)
112{
113 int cpu;
114 struct hv_per_cpu_context *hv_cpu;
115
116 /*
117 * First, zero all per-cpu memory areas so hv_synic_free() can
118 * detect what memory has been allocated and cleanup properly
119 * after any failures.
120 */
121 for_each_present_cpu(cpu) {
122 hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu);
123 memset(hv_cpu, 0, sizeof(*hv_cpu));
124 }
125
126 hv_context.hv_numa_map = kcalloc(nr_node_ids, sizeof(struct cpumask),
127 GFP_KERNEL);
128 if (hv_context.hv_numa_map == NULL) {
129 pr_err("Unable to allocate NUMA map\n");
130 goto err;
131 }
132
133 for_each_present_cpu(cpu) {
134 hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu);
135
136 tasklet_init(&hv_cpu->msg_dpc,
137 vmbus_on_msg_dpc, (unsigned long) hv_cpu);
138
139 hv_cpu->synic_message_page =
140 (void *)get_zeroed_page(GFP_ATOMIC);
141 if (hv_cpu->synic_message_page == NULL) {
142 pr_err("Unable to allocate SYNIC message page\n");
143 goto err;
144 }
145
146 hv_cpu->synic_event_page = (void *)get_zeroed_page(GFP_ATOMIC);
147 if (hv_cpu->synic_event_page == NULL) {
148 pr_err("Unable to allocate SYNIC event page\n");
149 goto err;
150 }
151
152 hv_cpu->post_msg_page = (void *)get_zeroed_page(GFP_ATOMIC);
153 if (hv_cpu->post_msg_page == NULL) {
154 pr_err("Unable to allocate post msg page\n");
155 goto err;
156 }
157 }
158
159 return 0;
160err:
161 /*
162 * Any memory allocations that succeeded will be freed when
163 * the caller cleans up by calling hv_synic_free()
164 */
165 return -ENOMEM;
166}
167
168
169void hv_synic_free(void)
170{
171 int cpu;
172
173 for_each_present_cpu(cpu) {
174 struct hv_per_cpu_context *hv_cpu
175 = per_cpu_ptr(hv_context.cpu_context, cpu);
176
177 free_page((unsigned long)hv_cpu->synic_event_page);
178 free_page((unsigned long)hv_cpu->synic_message_page);
179 free_page((unsigned long)hv_cpu->post_msg_page);
180 }
181
182 kfree(hv_context.hv_numa_map);
183}
184
185/*
186 * hv_synic_init - Initialize the Synthetic Interrupt Controller.
187 *
188 * If it is already initialized by another entity (ie x2v shim), we need to
189 * retrieve the initialized message and event pages. Otherwise, we create and
190 * initialize the message and event pages.
191 */
192void hv_synic_enable_regs(unsigned int cpu)
193{
194 struct hv_per_cpu_context *hv_cpu
195 = per_cpu_ptr(hv_context.cpu_context, cpu);
196 union hv_synic_simp simp;
197 union hv_synic_siefp siefp;
198 union hv_synic_sint shared_sint;
199 union hv_synic_scontrol sctrl;
200
201 /* Setup the Synic's message page */
202 simp.as_uint64 = hv_get_register(HV_REGISTER_SIMP);
203 simp.simp_enabled = 1;
204 simp.base_simp_gpa = virt_to_phys(hv_cpu->synic_message_page)
205 >> HV_HYP_PAGE_SHIFT;
206
207 hv_set_register(HV_REGISTER_SIMP, simp.as_uint64);
208
209 /* Setup the Synic's event page */
210 siefp.as_uint64 = hv_get_register(HV_REGISTER_SIEFP);
211 siefp.siefp_enabled = 1;
212 siefp.base_siefp_gpa = virt_to_phys(hv_cpu->synic_event_page)
213 >> HV_HYP_PAGE_SHIFT;
214
215 hv_set_register(HV_REGISTER_SIEFP, siefp.as_uint64);
216
217 /* Setup the shared SINT. */
218 if (vmbus_irq != -1)
219 enable_percpu_irq(vmbus_irq, 0);
220 shared_sint.as_uint64 = hv_get_register(HV_REGISTER_SINT0 +
221 VMBUS_MESSAGE_SINT);
222
223 shared_sint.vector = vmbus_interrupt;
224 shared_sint.masked = false;
225
226 /*
227 * On architectures where Hyper-V doesn't support AEOI (e.g., ARM64),
228 * it doesn't provide a recommendation flag and AEOI must be disabled.
229 */
230#ifdef HV_DEPRECATING_AEOI_RECOMMENDED
231 shared_sint.auto_eoi =
232 !(ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED);
233#else
234 shared_sint.auto_eoi = 0;
235#endif
236 hv_set_register(HV_REGISTER_SINT0 + VMBUS_MESSAGE_SINT,
237 shared_sint.as_uint64);
238
239 /* Enable the global synic bit */
240 sctrl.as_uint64 = hv_get_register(HV_REGISTER_SCONTROL);
241 sctrl.enable = 1;
242
243 hv_set_register(HV_REGISTER_SCONTROL, sctrl.as_uint64);
244}
245
246int hv_synic_init(unsigned int cpu)
247{
248 hv_synic_enable_regs(cpu);
249
250 hv_stimer_legacy_init(cpu, VMBUS_MESSAGE_SINT);
251
252 return 0;
253}
254
255/*
256 * hv_synic_cleanup - Cleanup routine for hv_synic_init().
257 */
258void hv_synic_disable_regs(unsigned int cpu)
259{
260 union hv_synic_sint shared_sint;
261 union hv_synic_simp simp;
262 union hv_synic_siefp siefp;
263 union hv_synic_scontrol sctrl;
264
265 shared_sint.as_uint64 = hv_get_register(HV_REGISTER_SINT0 +
266 VMBUS_MESSAGE_SINT);
267
268 shared_sint.masked = 1;
269
270 /* Need to correctly cleanup in the case of SMP!!! */
271 /* Disable the interrupt */
272 hv_set_register(HV_REGISTER_SINT0 + VMBUS_MESSAGE_SINT,
273 shared_sint.as_uint64);
274
275 simp.as_uint64 = hv_get_register(HV_REGISTER_SIMP);
276 simp.simp_enabled = 0;
277 simp.base_simp_gpa = 0;
278
279 hv_set_register(HV_REGISTER_SIMP, simp.as_uint64);
280
281 siefp.as_uint64 = hv_get_register(HV_REGISTER_SIEFP);
282 siefp.siefp_enabled = 0;
283 siefp.base_siefp_gpa = 0;
284
285 hv_set_register(HV_REGISTER_SIEFP, siefp.as_uint64);
286
287 /* Disable the global synic bit */
288 sctrl.as_uint64 = hv_get_register(HV_REGISTER_SCONTROL);
289 sctrl.enable = 0;
290 hv_set_register(HV_REGISTER_SCONTROL, sctrl.as_uint64);
291
292 if (vmbus_irq != -1)
293 disable_percpu_irq(vmbus_irq);
294}
295
296#define HV_MAX_TRIES 3
297/*
298 * Scan the event flags page of 'this' CPU looking for any bit that is set. If we find one
299 * bit set, then wait for a few milliseconds. Repeat these steps for a maximum of 3 times.
300 * Return 'true', if there is still any set bit after this operation; 'false', otherwise.
301 *
302 * If a bit is set, that means there is a pending channel interrupt. The expectation is
303 * that the normal interrupt handling mechanism will find and process the channel interrupt
304 * "very soon", and in the process clear the bit.
305 */
306static bool hv_synic_event_pending(void)
307{
308 struct hv_per_cpu_context *hv_cpu = this_cpu_ptr(hv_context.cpu_context);
309 union hv_synic_event_flags *event =
310 (union hv_synic_event_flags *)hv_cpu->synic_event_page + VMBUS_MESSAGE_SINT;
311 unsigned long *recv_int_page = event->flags; /* assumes VMBus version >= VERSION_WIN8 */
312 bool pending;
313 u32 relid;
314 int tries = 0;
315
316retry:
317 pending = false;
318 for_each_set_bit(relid, recv_int_page, HV_EVENT_FLAGS_COUNT) {
319 /* Special case - VMBus channel protocol messages */
320 if (relid == 0)
321 continue;
322 pending = true;
323 break;
324 }
325 if (pending && tries++ < HV_MAX_TRIES) {
326 usleep_range(10000, 20000);
327 goto retry;
328 }
329 return pending;
330}
331
332int hv_synic_cleanup(unsigned int cpu)
333{
334 struct vmbus_channel *channel, *sc;
335 bool channel_found = false;
336
337 if (vmbus_connection.conn_state != CONNECTED)
338 goto always_cleanup;
339
340 /*
341 * Hyper-V does not provide a way to change the connect CPU once
342 * it is set; we must prevent the connect CPU from going offline
343 * while the VM is running normally. But in the panic or kexec()
344 * path where the vmbus is already disconnected, the CPU must be
345 * allowed to shut down.
346 */
347 if (cpu == VMBUS_CONNECT_CPU)
348 return -EBUSY;
349
350 /*
351 * Search for channels which are bound to the CPU we're about to
352 * cleanup. In case we find one and vmbus is still connected, we
353 * fail; this will effectively prevent CPU offlining.
354 *
355 * TODO: Re-bind the channels to different CPUs.
356 */
357 mutex_lock(&vmbus_connection.channel_mutex);
358 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
359 if (channel->target_cpu == cpu) {
360 channel_found = true;
361 break;
362 }
363 list_for_each_entry(sc, &channel->sc_list, sc_list) {
364 if (sc->target_cpu == cpu) {
365 channel_found = true;
366 break;
367 }
368 }
369 if (channel_found)
370 break;
371 }
372 mutex_unlock(&vmbus_connection.channel_mutex);
373
374 if (channel_found)
375 return -EBUSY;
376
377 /*
378 * channel_found == false means that any channels that were previously
379 * assigned to the CPU have been reassigned elsewhere with a call of
380 * vmbus_send_modifychannel(). Scan the event flags page looking for
381 * bits that are set and waiting with a timeout for vmbus_chan_sched()
382 * to process such bits. If bits are still set after this operation
383 * and VMBus is connected, fail the CPU offlining operation.
384 */
385 if (vmbus_proto_version >= VERSION_WIN10_V4_1 && hv_synic_event_pending())
386 return -EBUSY;
387
388always_cleanup:
389 hv_stimer_legacy_cleanup(cpu);
390
391 hv_synic_disable_regs(cpu);
392
393 return 0;
394}