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 };
  40
  41 #define HV_TIMER_FREQUENCY (10 * 1000 * 1000) /* 100ns period */
  42 #define HV_MAX_MAX_DELTA_TICKS 0xffffffff
  43 #define HV_MIN_DELTA_TICKS 1
  44
  45 /*
  46  * hv_init - Main initialization routine.
  47  *
  48  * This routine must be called before any other routines in here are called
  49  */
  50 int hv_init(void)
  51 {
  52         if (!hv_is_hypercall_page_setup())
  53                 return -ENOTSUPP;
  54
  55         hv_context.cpu_context = alloc_percpu(struct hv_per_cpu_context);
  56         if (!hv_context.cpu_context)
  57                 return -ENOMEM;
  58
  59         return 0;
  60 }
  61
  62 /*
  63  * hv_post_message - Post a message using the hypervisor message IPC.
  64  *
  65  * This involves a hypercall.
  66  */
  67 int hv_post_message(union hv_connection_id connection_id,
  68                   enum hv_message_type message_type,
  69                   void *payload, size_t payload_size)
  70 {
  71         struct hv_input_post_message *aligned_msg;
  72         struct hv_per_cpu_context *hv_cpu;
  73         u64 status;
  74
  75         if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
  76                 return -EMSGSIZE;
  77
  78         hv_cpu = get_cpu_ptr(hv_context.cpu_context);
  79         aligned_msg = hv_cpu->post_msg_page;
  80         aligned_msg->connectionid = connection_id;
  81         aligned_msg->reserved = 0;
  82         aligned_msg->message_type = message_type;
  83         aligned_msg->payload_size = payload_size;
  84         memcpy((void *)aligned_msg->payload, payload, payload_size);
  85
  86         status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL);
  87
  88         /* Preemption must remain disabled until after the hypercall
  89          * so some other thread can't get scheduled onto this cpu and
  90          * corrupt the per-cpu post_msg_page
  91          */
  92         put_cpu_ptr(hv_cpu);
  93
  94         return status & 0xFFFF;
  95 }
  96
  97 static int hv_ce_set_next_event(unsigned long delta,
  98                                 struct clock_event_device *evt)
  99 {
 100         u64 current_tick;
 101
 102         WARN_ON(!clockevent_state_oneshot(evt));
 103
 104         current_tick = hyperv_cs->read(NULL);
 105         current_tick += delta;
 106         hv_init_timer(HV_X64_MSR_STIMER0_COUNT, current_tick);
 107         return 0;
 108 }
 109
 110 static int hv_ce_shutdown(struct clock_event_device *evt)
 111 {
 112         hv_init_timer(HV_X64_MSR_STIMER0_COUNT, 0);
 113         hv_init_timer_config(HV_X64_MSR_STIMER0_CONFIG, 0);
 114
 115         return 0;
 116 }
 117
 118 static int hv_ce_set_oneshot(struct clock_event_device *evt)
 119 {
 120         union hv_timer_config timer_cfg;
 121
 122         timer_cfg.enable = 1;
 123         timer_cfg.auto_enable = 1;
 124         timer_cfg.sintx = VMBUS_MESSAGE_SINT;
 125         hv_init_timer_config(HV_X64_MSR_STIMER0_CONFIG, timer_cfg.as_uint64);
 126
 127         return 0;
 128 }
 129
 130 static void hv_init_clockevent_device(struct clock_event_device *dev, int cpu)
 131 {
 132         dev->name = "Hyper-V clockevent";
 133         dev->features = CLOCK_EVT_FEAT_ONESHOT;
 134         dev->cpumask = cpumask_of(cpu);
 135         dev->rating = 1000;
 136         /*
 137          * Avoid settint dev->owner = THIS_MODULE deliberately as doing so will
 138          * result in clockevents_config_and_register() taking additional
 139          * references to the hv_vmbus module making it impossible to unload.
 140          */
 141
 142         dev->set_state_shutdown = hv_ce_shutdown;
 143         dev->set_state_oneshot = hv_ce_set_oneshot;
 144         dev->set_next_event = hv_ce_set_next_event;
 145 }
 146
 147
 148 int hv_synic_alloc(void)
 149 {
 150         int cpu;
 151
 152         hv_context.hv_numa_map = kzalloc(sizeof(struct cpumask) * nr_node_ids,
 153                                          GFP_ATOMIC);
 154         if (hv_context.hv_numa_map == NULL) {
 155                 pr_err("Unable to allocate NUMA map\n");
 156                 goto err;
 157         }
 158
 159         for_each_present_cpu(cpu) {
 160                 struct hv_per_cpu_context *hv_cpu
 161                         = per_cpu_ptr(hv_context.cpu_context, cpu);
 162
 163                 memset(hv_cpu, 0, sizeof(*hv_cpu));
 164                 tasklet_init(&hv_cpu->msg_dpc,
 165                              vmbus_on_msg_dpc, (unsigned long) hv_cpu);
 166
 167                 hv_cpu->clk_evt = kzalloc(sizeof(struct clock_event_device),
 168                                           GFP_KERNEL);
 169                 if (hv_cpu->clk_evt == NULL) {
 170                         pr_err("Unable to allocate clock event device\n");
 171                         goto err;
 172                 }
 173                 hv_init_clockevent_device(hv_cpu->clk_evt, cpu);
 174
 175                 hv_cpu->synic_message_page =
 176                         (void *)get_zeroed_page(GFP_ATOMIC);
 177                 if (hv_cpu->synic_message_page == NULL) {
 178                         pr_err("Unable to allocate SYNIC message page\n");
 179                         goto err;
 180                 }
 181
 182                 hv_cpu->synic_event_page = (void *)get_zeroed_page(GFP_ATOMIC);
 183                 if (hv_cpu->synic_event_page == NULL) {
 184                         pr_err("Unable to allocate SYNIC event page\n");
 185                         goto err;
 186                 }
 187
 188                 hv_cpu->post_msg_page = (void *)get_zeroed_page(GFP_ATOMIC);
 189                 if (hv_cpu->post_msg_page == NULL) {
 190                         pr_err("Unable to allocate post msg page\n");
 191                         goto err;
 192                 }
 193
 194                 INIT_LIST_HEAD(&hv_cpu->chan_list);
 195         }
 196
 197         return 0;
 198 err:
 199         return -ENOMEM;
 200 }
 201
 202
 203 void hv_synic_free(void)
 204 {
 205         int cpu;
 206
 207         for_each_present_cpu(cpu) {
 208                 struct hv_per_cpu_context *hv_cpu
 209                         = per_cpu_ptr(hv_context.cpu_context, cpu);
 210
 211                 if (hv_cpu->synic_event_page)
 212                         free_page((unsigned long)hv_cpu->synic_event_page);
 213                 if (hv_cpu->synic_message_page)
 214                         free_page((unsigned long)hv_cpu->synic_message_page);
 215                 if (hv_cpu->post_msg_page)
 216                         free_page((unsigned long)hv_cpu->post_msg_page);
 217         }
 218
 219         kfree(hv_context.hv_numa_map);
 220 }
 221
 222 /*
 223  * hv_synic_init - Initialize the Synthethic Interrupt Controller.
 224  *
 225  * If it is already initialized by another entity (ie x2v shim), we need to
 226  * retrieve the initialized message and event pages.  Otherwise, we create and
 227  * initialize the message and event pages.
 228  */
 229 int hv_synic_init(unsigned int cpu)
 230 {
 231         struct hv_per_cpu_context *hv_cpu
 232                 = per_cpu_ptr(hv_context.cpu_context, cpu);
 233         union hv_synic_simp simp;
 234         union hv_synic_siefp siefp;
 235         union hv_synic_sint shared_sint;
 236         union hv_synic_scontrol sctrl;
 237
 238         /* Setup the Synic's message page */
 239         hv_get_simp(simp.as_uint64);
 240         simp.simp_enabled = 1;
 241         simp.base_simp_gpa = virt_to_phys(hv_cpu->synic_message_page)
 242                 >> PAGE_SHIFT;
 243
 244         hv_set_simp(simp.as_uint64);
 245
 246         /* Setup the Synic's event page */
 247         hv_get_siefp(siefp.as_uint64);
 248         siefp.siefp_enabled = 1;
 249         siefp.base_siefp_gpa = virt_to_phys(hv_cpu->synic_event_page)
 250                 >> PAGE_SHIFT;
 251
 252         hv_set_siefp(siefp.as_uint64);
 253
 254         /* Setup the shared SINT. */
 255         hv_get_synint_state(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT,
 256                             shared_sint.as_uint64);
 257
 258         shared_sint.as_uint64 = 0;
 259         shared_sint.vector = HYPERVISOR_CALLBACK_VECTOR;
 260         shared_sint.masked = false;
 261         if (ms_hyperv.hints & HV_X64_DEPRECATING_AEOI_RECOMMENDED)
 262                 shared_sint.auto_eoi = false;
 263         else
 264                 shared_sint.auto_eoi = true;
 265
 266         hv_set_synint_state(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT,
 267                             shared_sint.as_uint64);
 268
 269         /* Enable the global synic bit */
 270         hv_get_synic_state(sctrl.as_uint64);
 271         sctrl.enable = 1;
 272
 273         hv_set_synic_state(sctrl.as_uint64);
 274
 275         hv_context.synic_initialized = true;
 276
 277         /*
 278          * Register the per-cpu clockevent source.
 279          */
 280         if (ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE)
 281                 clockevents_config_and_register(hv_cpu->clk_evt,
 282                                                 HV_TIMER_FREQUENCY,
 283                                                 HV_MIN_DELTA_TICKS,
 284                                                 HV_MAX_MAX_DELTA_TICKS);
 285         return 0;
 286 }
 287
 288 /*
 289  * hv_synic_clockevents_cleanup - Cleanup clockevent devices
 290  */
 291 void hv_synic_clockevents_cleanup(void)
 292 {
 293         int cpu;
 294
 295         if (!(ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE))
 296                 return;
 297
 298         for_each_present_cpu(cpu) {
 299                 struct hv_per_cpu_context *hv_cpu
 300                         = per_cpu_ptr(hv_context.cpu_context, cpu);
 301
 302                 clockevents_unbind_device(hv_cpu->clk_evt, cpu);
 303         }
 304 }
 305
 306 /*
 307  * hv_synic_cleanup - Cleanup routine for hv_synic_init().
 308  */
 309 int hv_synic_cleanup(unsigned int cpu)
 310 {
 311         union hv_synic_sint shared_sint;
 312         union hv_synic_simp simp;
 313         union hv_synic_siefp siefp;
 314         union hv_synic_scontrol sctrl;
 315         struct vmbus_channel *channel, *sc;
 316         bool channel_found = false;
 317         unsigned long flags;
 318
 319         if (!hv_context.synic_initialized)
 320                 return -EFAULT;
 321
 322         /*
 323          * Search for channels which are bound to the CPU we're about to
 324          * cleanup. In case we find one and vmbus is still connected we need to
 325          * fail, this will effectively prevent CPU offlining. There is no way
 326          * we can re-bind channels to different CPUs for now.
 327          */
 328         mutex_lock(&vmbus_connection.channel_mutex);
 329         list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
 330                 if (channel->target_cpu == cpu) {
 331                         channel_found = true;
 332                         break;
 333                 }
 334                 spin_lock_irqsave(&channel->lock, flags);
 335                 list_for_each_entry(sc, &channel->sc_list, sc_list) {
 336                         if (sc->target_cpu == cpu) {
 337                                 channel_found = true;
 338                                 break;
 339                         }
 340                 }
 341                 spin_unlock_irqrestore(&channel->lock, flags);
 342                 if (channel_found)
 343                         break;
 344         }
 345         mutex_unlock(&vmbus_connection.channel_mutex);
 346
 347         if (channel_found && vmbus_connection.conn_state == CONNECTED)
 348                 return -EBUSY;
 349
 350         /* Turn off clockevent device */
 351         if (ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE) {
 352                 struct hv_per_cpu_context *hv_cpu
 353                         = this_cpu_ptr(hv_context.cpu_context);
 354
 355                 clockevents_unbind_device(hv_cpu->clk_evt, cpu);
 356                 hv_ce_shutdown(hv_cpu->clk_evt);
 357                 put_cpu_ptr(hv_cpu);
 358         }
 359
 360         hv_get_synint_state(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT,
 361                             shared_sint.as_uint64);
 362
 363         shared_sint.masked = 1;
 364
 365         /* Need to correctly cleanup in the case of SMP!!! */
 366         /* Disable the interrupt */
 367         hv_set_synint_state(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT,
 368                             shared_sint.as_uint64);
 369
 370         hv_get_simp(simp.as_uint64);
 371         simp.simp_enabled = 0;
 372         simp.base_simp_gpa = 0;
 373
 374         hv_set_simp(simp.as_uint64);
 375
 376         hv_get_siefp(siefp.as_uint64);
 377         siefp.siefp_enabled = 0;
 378         siefp.base_siefp_gpa = 0;
 379
 380         hv_set_siefp(siefp.as_uint64);
 381
 382         /* Disable the global synic bit */
 383         hv_get_synic_state(sctrl.as_uint64);
 384         sctrl.enable = 0;
 385         hv_set_synic_state(sctrl.as_uint64);
 386
 387         return 0;
 388 }