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